Electrostatic precipitator for nuclide sampling

Abstract

Monitoring airborne radionuclides in an environment can be difficult because of different elements in ambient air. A nuclide sampling apparatus is provided that includes a first electrostatic precipitator subsystem comprising a first electrostatic precipitator, a first sample collector, and a first spectrometer system. The air outlet of the first electrostatic precipitator subsystem is fluidly connected to an inlet of a reactor subsystem. An outlet of the reactor subsystem is fluidly connected to an air inlet of a second electrostatic precipitator subsystem, which similarly comprises a second electrostatic precipitator, a second sample collector, and a second spectrometer system. In some cases, the reactor subsystem reacts ozone, provided by an ozone generator, with iodine gas, which exists in the ambient air that was not collected first sample collector, to produce iodine oxide aerosols that are collected by the second sample collector.

Description

ELECTROSTATIC PRECIPITATOR FOR NUCLIDE SAMPLINGCROSS-REFERENCE TO RELATED APPLICATION

[0001] This patent application claims priority to United States Provisional Patent Application No. 63 / 614,013 filed on December 22, 2023 and entitled “ELECTROSTATIC PRECIPITATOR FOR RADIONUCLIDE SAMPLING”, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The following disclosure generally relates to an electrostatic precipitator for nuclide sampling, and, more particularly, to an electrostatic precipitator for radionuclide sampling.DESCRIPTION OF THE RELATED ART

[0003] PCT Patent Application Publication No. WO 2023 / 000093 A1 discloses a portable system for monitoring radionuclides. The disclosed system is configured to automatically use two or more filters over a given detection period which purportedly helps improve the temporal resolution of the measurements. The system also includes at least two different types of filters, such as at least one aerosol filter and at least one iodine filter, that can be configured to capture different radionuclides from an incoming air sample. Preferably, the disclosed system can separately detect the radionuclides captured on each filter. The in-situ measurements are accomplished with a pair of cadmium zinc telluride (CZT) gamma spectrometers (or other suitable detectors, one associated with each filter). These detectors can collect data while the system is sampling from the air.

[0004] US Patent No. 8,043,412 is directed to a portable electrostatic precipitator capable of collecting analytes from air and concentrating them on or in appropriately selected collection media. An electrostatic precipitator that is portable and can accommodate a variety of collection media at relatively high rates of air flow may be used to detect trace chemicals or bacteria.

[0005] Gouello et al. disclose a process to filter gaseous iodine and iodine containing particles (e.g., IxOy) from a radioactive discharge. The disclosed system consists of a combination of an ozone feed and a wet electrostatic precipitator (WESP). The electrostatic precipitation (ESP) technique is widely used in the industry to filter out impurities (i.e., particles) in gases. The advantage of a WESP is that the impurities are removed from the system with a solution. They can thus directly be transported to a water container, such as the sump in a nuclear power plant thus mitigating the release of iodine into the environment [Gouello, Melany, Hokkinen, Jouni, Karkela, Teemu, & Auvinen, Ari (2017) Proceedings of2017 International Congress on Advances in Nuclear Power Plants (ICAPP2017), (p. 2573), Japan],

[0006] There is still a desire for an improved sampling device that can provide information on the composition of radioactive releases into the atmosphere including, but not limited to, iodine.SUMMARY

[0007] This summary is intended to introduce the reader to the more detailed description that follows and not to limit or define any claimed or as yet unclaimed invention. One or more inventions may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures.

[0008] In at least one broad example aspect, a nuclide sampling apparatus is provided comprising: a first electrostatic precipitator subsystem comprising a first housing defining therein a first chamber, a first air inlet of the first chamber, a first air outlet of the first chamber, a first electrostatic precipitator positioned within the first chamber, and a first sample collector positioned within the first chamber; a reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, and a reactor air outlet of the reactor chamber; a second electrostatic precipitator subsystem comprising a second housing defining therein a second chamber, a second air inlet of the second chamber, a second air outlet of the second chamber, a second electrostatic precipitator positioned within the second chamber, and a second sample collector positioned within the second chamber; and, wherein the first air outlet is fluidly connected to the reactor air inlet, the reactor air outlet is fluidly connected to the second air inlet.

[0009] In some cases, the reactor subsystem further comprises an ozone inlet that is fluidly connected to the reactor chamber, and the ozone inlet is configured to receive ozone that flows into the reactor chamber.

[0010] In some cases, the nuclide sampling device further comprises an ozone generator that is configured to provide the ozone to the ozone inlet.

[0011] In some cases, the first electrostatic precipitator comprises a first electrode that is positioned fluidly downstream from the first air inlet and fluidly upstream from the first sample collector; and wherein the second electrostatic precipitator comprises a second electrode that is positioned fluidly downstream from the second air inlet and fluidly upstream from the second sample collector.

[0012] In some cases, the first electrode and the second electrode each defines therein one or more air openings.

[0013] In some cases, the first electrode and the second electrode each comprises an air- permeable mesh.

[0014] In some cases, the first air inlet comprises a first inlet tube, the first inlet tube comprising a first end positioned external to the first chamber and a second end positioned within the first chamber, and the first electrode is positioned on the second end of the first inlet tube; and wherein the second air inlet comprises a second inlet tube, the second inlet tube comprising a first end positioned external to the second chamber and a second end positioned within the second chamber, and the second electrode is positioned on the second end of the second inlet tube.

[0015] In some cases, the first electrostatic precipitator subsystem further comprises a first spectrometer system, the first sample collector comprises a first deposition sheet that comprises a first deposition surface and a first opposite-facing surface, and the first deposition surface faces the first electrostatic precipitator and the first opposite-facing surface faces the first spectrometer system; and wherein the second electrostatic precipitator subsystem further comprises a second spectrometer system, the second sample collector comprises a second deposition sheet that comprises a second deposition surface and a second opposite-facing surface, and the second deposition surface faces the second electrostatic precipitator and the second opposite-facing surface faces the second spectrometer system.

[0016] In some cases, the first spectrometer system is fluidly isolated from the first chamber, and the second spectrometer system is fluidly isolated from the second chamber.

[0017] In some cases, the first housing comprises a first recess structure protruding inwardly into the first chamber and defines therein a first recess that is fluidly separated from the first chamber, the first recess structure comprises a first opening, and the first spectrometer system is positioned within the first recess and is removable and insertable via the first opening; and wherein the second housing comprises a second recess structure protruding inwardly into the second chamber and defines therein a second recess that is fluidly separated from the second chamber, the second recess structure comprises a second opening, and the second spectrometer system is positioned within the second recess and is removable and insertable via the second opening.

[0018] In some cases, the first housing defines within the first chamber a first air gap between at least one wall of the first housing and the first recess structure, the first air gap configured to facilitate airflow within the first chamber around the first recess structure; and wherein the second housing defines within the second chamber a second air gap between at least one wall of the second housing and the second recess structure, the second air gap configured to facilitate airflow within the second chamber around the second recess structure.

[0019] In some cases, the first spectrometer system comprises a first gamma spectrometer that is housed within a first shield that blocks gamma radiation; and wherein the second spectrometer system comprises a second gamma spectrometer that is housed within a second shield that blocks the gamma radiation.

[0020] In some cases, the nuclide sampling apparatus further comprises a computer in data communication with the first spectrometer and the second spectrometer, the computer configured to collect data from the first spectrometer system and the second spectrometer system and transmit the data via a network interface.

[0021] In some cases, the first housing further comprises a first sheet inlet through which the first deposition sheet enters into the first chamber; and wherein the second housing further comprises a second sheet inlet through which the second deposition sheet enters into the second chamber.

[0022] In some cases, the first housing further comprises a first sheet outlet through which the first deposition sheet exits the first chamber, the first sheet inlet and the first sheet outlet positioned on opposite-facing walls of the first housing; and wherein the second housing further comprises a second sheet outlet through which the second deposition sheet exits the second chamber, the second sheet inlet and the second sheet outlet positioned on oppositefacing walls of the second housing.

[0023] In some cases, the first deposition sheet is a portion of a first deposition film that is flexible, and wherein the first electrostatic precipitator subsystem further comprises a first film exchange roller system that comprises a first roller operable to pull the first deposition sheet across the first spectrometer system; and wherein the second deposition sheet is a portion of a second deposition film that is flexible, and wherein the second electrostatic precipitator subsystem further comprises a second film exchange roller system that comprises a second roller operable to pull the second deposition sheet across the second spectrometer system.

[0024] In some cases, the first roller and the second roller are respectively driven by a first motor and a second motor, and the first motor and the second motor are controllable by an electronic controller.

[0025] In some cases, the first deposition film comprises a first continuous metallic film strip, including the portion that forms the first deposition sheet; and wherein the second deposition film comprises a second continuous metallic film strip, including the portion that forms the second deposition sheet.

[0026] In some cases, the first deposition film comprises a plurality of discrete metallic sheets positioned in spaced relationship to each other along a first tape, and wherein the portion that forms the first deposition sheet comprises one of the plurality of discrete metallic sheets on the first tape; and wherein the second deposition film comprises a plurality of discrete metallic sheets positioned in spaced relationship to each other along a second tape, and wherein the portion that forms the second deposition sheet comprises one of the plurality of discrete metallic sheets on the second tape.

[0027] In some cases, the first deposition sheet is a first plate; and the second deposition sheet is a second plate.

[0028] In some cases, the reactor housing is an elongate tube and comprises one or more baffles positioned within the reactor chamber.

[0029] In some cases, a first baffle is positioned in proximity to the reactor air inlet and a second baffle is positioned in proximity to the reactor air outlet.

[0030] In some cases, the nuclide sampling device further comprises a fan that is positioned downstream from the second air outlet and is fluidly connected to the second air outlet, and the fan is configured to move air at least through: the first air inlet, the first chamber, the first air outlet, the reactor air inlet, the reactor chamber, the reactor air outlet, the second air inlet, the second chamber, and the second air outlet.

[0031] In another broad example aspect, a radionuclide sampling apparatus is provided comprising: a first electrostatic precipitator subsystem comprising a first housing defining therein a first chamber, a first air inlet of the first chamber, a first air outlet of the first chamber, a first electrostatic precipitator positioned within the first chamber, a first sample collector positioned within the first chamber, and a first gamma spectrometer system configured to detect a first sample of radionuclides collected at the first sample collector; an iodine reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, a reactor air outlet of the reactor chamber, an ozone generator subsystem comprising an ozone generator and an ozone outlet; a second electrostatic precipitator subsystem comprising a second housing defining therein a second chamber, a second air inlet of the second chamber, a second air outlet of the second chamber, a second electrostatic precipitator positioned within the second chamber, a second sample collector positioned within the second chamber, and a second gamma spectrometer system configured to detect a second sample of radionuclides collected at the second sample collector; wherein the reactor air inlet is fluidly connected to the first air outlet, and the reactor air outlet is fluidly connected to the second air inlet; wherein the ozone outlet is fluidly connected to the reactor chamber via an ozone inlet that is fluidly connected upstream to the reactor air inlet or that isfluidly connected directly to the reactor chamber; and wherein the reactor chamber receives ozone outputted from the ozone generator and iodine gas outputted from the first air outlet, facilitates a reaction between the ozone and the iodine gas to generate iodine oxide aerosol, and outputs the iodine oxide aerosol to the second chamber.

[0032] In another broad example aspect, a radionuclide sampling apparatus is provided comprising: a reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, and a reactor air outlet of the reactor chamber; the reactor subsystem further comprising an ozone inlet that is fluidly connected to the reactor chamber, and the ozone inlet is configured to receive ozone that flows into the reactor chamber; an ozone generator that is configured to provide the ozone to the ozone inlet; a computer in data communication with the ozone generator configured to control the ozone generator to operate in a first operating mode that generates the ozone and operate in a second operating mode that does not generate the ozone; an electrostatic precipitator subsystem comprising a housing defining therein a chamber, an air inlet of the chamber, an air outlet of the chamber, an electrostatic precipitator positioned within the chamber, a sample collector positioned within the chamber, and a spectrometer system configured to detect radionuclides collected at the sample collector; and wherein the reactor air outlet is fluidly connected to the air inlet.

[0033] In some cases, in the first operating mode, the ozone flows into the reactor chamber and reacts with iodine gas in air flowing though the reactor air inlet to produce aerosolized iodine oxides.

[0034] In some cases, the computer is also configured to control and communicate with the spectrometer system; wherein the computer controls the ozone generator to operate in the first operating mode for a first time period and collects a first measurement from the spectrometer system during the first time period; and wherein the computer controls the ozone generator to operate in the second operating mode for a second time period and collects a second measurement from the spectrometer system during the second time period.

[0035] In some cases, during the first time period, the first measurement is made using a first deposition surface as the sample collector; and, during the second time period, the second measurement is made using a second deposition surface as the sample collector; and, wherein the second deposition surface is new compared to the first deposition surface.

[0036] In some cases, the second deposition surface replaces the first deposition surface as the sample collector before the second measurement is collected.

[0037] In some cases, the computer detects that the second deposition surface has replaced the first deposition surface as the sample collector before the computer controls the ozone generator to operate in the second operating mode.

[0038] In some cases, the computer stores thereon executable instructions to compute a difference between the second measurement and the first measurement to determine a gasphase iodine measurement in in air flowing into the reactor air inlet.

[0039] In some cases, the electrostatic precipitator comprises an electrode that is positioned fluidly downstream from the air inlet of the chamber and fluidly upstream from the sample collector.

[0040] In some cases, the electrode defines therein one or more air openings.

[0041] In some cases, the electrode comprises an air-permeable mesh.

[0042] In some cases, the air inlet of the chamber comprises an inlet tube, the inlet tube comprising a first end positioned external to the chamber and a second end positioned within the chamber, and the electrode is positioned on the second end of the inlet tube.

[0043] In some cases, the sample collector comprises a deposition sheet that comprises a deposition surface and an opposite-facing surface, and the deposition surface faces the electrostatic precipitator and the opposite-facing surface faces the spectrometer system.

[0044] In some cases, the spectrometer system is fluidly isolated from the chamber.

[0045] In some cases, the housing comprises a recess structure protruding inwardly into the chamber and defines therein a recess that is fluidly separated from the chamber, the recess structure comprises an opening, and the spectrometer system is positioned within the recess and is removable and insertable via the opening.

[0046] In some cases, the housing defines within the chamber an air gap between at least one wall of the housing and the recess structure, the air gap configured to facilitate airflow within the chamber around the recess structure.

[0047] In some cases, the deposition sheet is a portion of a deposition film that is flexible, and wherein the electrostatic precipitator subsystem further comprises a film exchange roller system that comprises a roller operable to pull the deposition sheet across the spectrometer system.

[0048] In some cases, the roller is driven by a motor, and the motor is controllable by the computer.

[0049] In some cases, the deposition film comprises a continuous metallic film strip, including the portion that forms the deposition sheet.

[0050] In some cases, the deposition film comprises a plurality of discrete metallic sheets positioned in spaced relationship to each other along a tape, and wherein the portion that forms the deposition sheet comprises one of the plurality of discrete metallic sheets on the tape.

[0051] In some cases, the deposition sheet is a plate.

[0052] In some cases, the reactor housing is an elongate tube and comprises one or more baffles positioned within the reactor chamber.

[0053] In some cases, a first baffle is positioned in proximity to the reactor air inlet and a second baffle is positioned in proximity to the reactor air outlet.

[0054] In some cases, the radionuclide sampling device further comprises a fan that is positioned downstream from the air outlet of the chamber and is fluidly connected to the air outlet of the chamber, and the fan is configured to move air at least through: the reactor air inlet, the reactor chamber, the reactor air outlet, the air inlet of the chamber, the chamber, and the air outlet of the chamber.

[0055] In some cases, the spectrometer system comprises a gamma spectrometer that is housed within a shield that blocks gamma radiation.

[0056] In another broad example aspect, a radionuclide sampling apparatus is provided comprising: a first stage and a second stage that are configured to be fluidly parallel to each other; the first stage comprising a first electrostatic precipitator subsystem comprising a first housing defining therein a first chamber, a first air inlet of the first chamber, a first air outlet of the first chamber, a first electrostatic precipitator positioned within the first chamber, a first sample collector positioned within the first chamber, and a first spectrometer system configured to detect radionuclides collected at the first sample collector; the second stage comprising a reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, and a reactor air outlet of the reactor chamber; the reactor subsystem further comprising an ozone inlet that is fluidly connected to the reactor chamber, and the ozone inlet is configured to receive ozone that flows into the reactor chamber; the second stage further comprising an ozone generator that is configured to provide the ozone to the ozone inlet; the second stage further comprising a second electrostatic precipitator subsystem comprising a second housing defining therein a second chamber, a second air inlet of the second chamber, a second air outlet of the second chamber, a second electrostatic precipitator positioned within the second chamber, a second sample collector positioned within the second chamber, and a second spectrometer system configured to detect radionuclides collected at the second sample collector, and wherein the second reactor air outlet is fluidly connected to the second air inlet of the second chamber;and a computer in data communication with the first spectrometer system and the second spectrometer system. In another broad example aspect, a method is provided for using a nuclide sampling apparatus as described herein, including for radionuclide sampling.BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The drawings included herewith are for illustrating various examples of apparatus, methods, and systems of the present specification and are not intended to limit the scope of what is taught in any way. In the drawings:

[0058] FIG. 1 A is a schematic diagram of an apparatus for nuclide sampling, according to an example embodiment;

[0059] FIG. 1 B is a schematic diagram of an apparatus for nuclide sampling, according to another example embodiment;

[0060] FIG. 2 is a schematic diagram of an apparatus for nuclide sampling, according to another example embodiment;

[0061] FIG. 3 is a schematic diagram of an electrostatic precipitator subsystem according to an example embodiment, shown in isolation;

[0062] FIG. 4A is a perspective view of an electrostatic precipitator subsystem shown in isolation, and further showing a deposition sheet and a spectrometer being inserted into a recess within the electrostatic precipitator subsystem, according to another example embodiment;

[0063] FIG. 4B is a cross-sectional view taken along the line 400A-400A in FIG. 4A, and further showing the deposition sheet and the spectrometer position within the electrostatic precipitator subsystem, according to an example embodiment;

[0064] FIG. 5A is a schematic diagram of an apparatus for nuclide sampling, further showing a film exchange roller system that is operable to replace a used deposition sheet with a new deposition sheet, according to an example embodiment;

[0065] FIG. 5B is a schematic diagram of an apparatus for nuclide sampling, and further showing a film exchange roller system housed within a chamber of an electrostatic precipitator subsystem, according to an example embodiment;

[0066] FIG. 5C is a top schematic view of a continuous metallic strip that includes a plurality of portions of deposition sheets, according to an example embodiment;

[0067] FIG. 5D is a top schematic view of a plurality of discrete metallic sheets positioned in spaced relationship to each other along a non-metallic tape, according to an example embodiment;

[0068] FIG. 6A is a perspective schematic view of an apparatus for nuclide sampling, according to another example embodiment;

[0069] FIG. 6B is a partial cross-sectional view of the housing of the electrostatic precipitator subsystem in the apparatus of FIG. 6A;

[0070] FIG. 6C is a partial cross-sectional view of the housing of the reactor in the apparatus of FIG. 6A;

[0071] FIG. 7 is a modelled view of airflow past an electrode of an electrostatic precipitator and around a deposition sheet that is a sample collector;

[0072] FIG. 8 is a modelled view of electric potential between an electrode of an electrostatic precipitator and a deposition sheet that is a sample collector;

[0073] FIG. 9A is a schematic diagram of an apparatus for nuclide sampling that includes a reactor and a single electrostatic precipitator operating in a first operating mode, according to an example embodiment;

[0074] FIG. 9B is a schematic diagram of the apparatus shown in FIG. 9A operating in a second operating mode; and

[0075] FIG. 10 is a schematic diagram of an apparatus for nuclide sampling that includes a first stage and a second stage configured to be fluidly parallel to each other, according to an example embodiment.DETAILED DESCRIPTION

[0076] It will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the example embodiments described herein. However, it will be understood by those of ordinary skill in the art that the example embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the example embodiments described herein. Also, the description is not to be considered as limiting the scope of the example embodiments described herein.

[0077] A major nuclear accident could emit a substantial amount of radioactivity into the atmosphere. For example, the Fukushima accident emitted xenon, iodine, cesium, and tellurium on the order of 1016to 1019Bq. Real-time (or near-real time) information on the composition of the releases, obtained in the field from environmental sampling, may offersubstantial input to decision makers. For example, the composition of the radionuclide mix has a considerable impact on projected doses obtained by the public.

[0078] Composition has important implications on off-site consequences estimation. As an example, high radioiodine concentrations would indicate that there would be a higher public risk for thyroid cancer, which could influence decisions to distribute iodine tablets, recommend sheltering, or recommend evacuation. As another example, the presence of certain radioisotopes like ruthenium may be considered indicators of severe core damage and could provide important information about the state of the reactor.

[0079] Some existing electrostatic precipitator-based monitoring systems add a static charge to the aerosols by running the input gas through a coronal discharge, and then cause the charged aerosols to migrate towards a deposition surface by applying a large electric potential. However, an electrostatic precipitator-based monitoring system does not typically capture gas-phase elements, for example, gas-phase iodine, effectively. In the case of environment radionuclide monitoring, detecting gas-phase iodine may provide more information about the radioactivity in the air.

[0080] A radionuclide monitoring setup would typically include an iodine filter placed downstream of an aerosol filter. However, utilizing filters can introduce complexity when trying to provide real-time monitoring. Also, replacing either filter can introduce complexity. For example, the filters would accumulate a build-up of radioactivity (including radio-iodine) over time, making it difficult to obtain samples for discrete time periods, different locations, or both. Accordingly, a typical filter-based setup may be considered difficult to use in the field where a human operator may have limited access.

[0081] In an example embodiment disclosed herein, a radionuclide sampling apparatus includes a first electrostatic precipitator stage, an iodine reactor stage, and a second electrostatic precipitator stage. Each electrostatic precipitator stage includes a sample collector. The iodine reactor receives ozone (e.g. from an ozone generator) and promotes mixing of ozone with iodine gas that may be present in air exiting the first electrostatic precipitator stage to generate iodine oxide aerosol (e.g., aerosolized IOX), which may be more readily collected in the second electrostatic precipitator stage.

[0082] In some cases, the sample collector can be operated mechanically. For example, the sample collector may promote deposition to occur onto a removable plate. Alternatively, the sample collector can include one or more sampling channels, so that a washing solution can be periodically run through the sample collector to re-suspend collected material and carry it away to e.g., a drain tank. In some other cases, the sample collector can be a deposition film exchange system.

[0083] In an example aspect, each electrostatic precipitator stage may have a detector, such as a gamma spectrometer, incorporated into it. Each gamma spectrometer may be housed in a shield of gamma blocking material, such as a tungsten shield. This can help to reduce or eliminate background radiation fields from interfering with the detector, such as from contamination of the ground surrounding the sampling apparatus, or from the other collection stage within the sampling apparatus.

[0084] In some cases, the gamma spectrometry results, as well as diagnostic information on the status of the instrument in general, are continuously collected by the sampling apparatus when the apparatus is deployed in the field. Some of the data processing may take place locally on an onboard computer. For example, software for running the gamma spectrometry apparatus may be run locally. In some cases, collected data and diagnostic information can be stored locally, with capability to locally access the data (e.g., eitherthrough download to a USB drive or other detachable storage device, or access by connecting the sampling apparatus to a USB port on a mobile computing device, such as a laptop or tablet computer). In some cases, the onboard computer is configured for real-time (or near-real-time) communication, so that other computing devices, for example, located at an emergency operations center, can receive real-time (or near-real-time) radionuclide sampling data and diagnostics.

[0085] In some cases, the sampling apparatus includes a rugged environmental container or a ruggedized housing so that it can operate outdoors in the presence of precipitation. In some embodiments, a heating and / or cooling system is incorporated into the apparatus so that certain electronic components can operate despite external temperature fluctuations. Additionally, or alternatively, a humidity control system can be incorporated into the sampling apparatus to influence the relative humidity of air within the sampling apparatus. Additionally, or alternatively, a temperature control system can be incorporated into the sampling apparatus to influence the temperature of air within the sampling apparatus. It will be appreciated that, in some cases, the temperature and / or relative humidity of air to be sampled may affect the efficiency of the electrostatic precipitators and / or iodine I ozone reaction chemistry.

[0086] It will be appreciated that the apparatus described herein can be used for nuclide sampling, and more specifically for radionuclide sampling.

[0087] Turning to FIG. 1A, an example of a nuclide sampling apparatus 100 is provided. The illustrated example includes a first electrostatic precipitator subsystem 110a, a reactor subsystem 130, and a second electrostatic precipitator subsystem 110b. The first electrostatic precipitator subsystem 110a includes a first housing 112a defining therein a first chamber 114a. The first electrostatic precipitator subsystem 110a also includes a first air inlet 116a ofthe first chamber 114a and a first air outlet 118a of the first chamber 114a. A first electrostatic precipitator 115a includes a first electrode 120a positioned within the first chamber 114a, and a first sample collector 122a positioned within the first chamber. During operation of the first electrostatic precipitator 115a, a first electrostatic field 121a is formed between the first electrode 120a and the first sample collector 122a. Air (e.g., ambient air to be sampled) can flow from the first air inlet 116a, past or through the first electrode 120a, through the first chamber 114a, and out the first air outlet 118a.

[0088] Reactor subsystem 130 includes a reactor housing 132 defining within it a reactor chamber 134. The illustrated example also includes a reactor air inlet 136 of the reactor chamber 134, and a reactor air outlet 138 of the reactor chamber 134. Air (e.g., air exiting first electrostatic precipitator subsystem 110a) can flow from the reactor air inlet 136, through the reactor chamber 134, and out the first air outlet 138.

[0089] The second electrostatic precipitator subsystem 110b includes a second housing 112b defining therein a second chamber 114b, a second air inlet 116b of the second chamber, a second air outlet 118b of the second chamber, and a second electrostatic precipitator 115b. The second electrostatic precipitator includes a second electrode 120b positioned within the second chamber, and a second sample collector 122b positioned within the second chamber. During operation of the second electrostatic precipitator 115b, a second electrostatic field 121 b is formed between the second electrode 120b and the second sample collector 122b. Air (e.g., air exiting reactor subsystem 130) can flow from the second air inlet 116b, past or through the second electrode 120b, through the second chamber 114b, and out the second air outlet 118b.

[0090] In the illustrated example, the first air outlet 118a is fluidly connected to the reactor air inlet 136, and the reactor air outlet 138 is fluidly connected to the second air inlet 116b. Accordingly, sampling apparatus 100 defines a gas flow path from first air inlet 116a to second air outlet 118b.

[0091] In the example illustrated in FIG. 1A, reactor subsystem 130 further comprises an ozone inlet 194 that is fluidly connected to the flow path between first air outlet 118a and reactor air inlet 136. As a result, ozone O3from the ozone inlet 194 can be introduced to air exiting the first air outlet 118a. In an example aspect, nuclide sampling apparatus 100 further includes an ozone generator 190 that is configured to generate ozone and provide the ozone to the ozone inlet 194 via an ozone outlet 192.

[0092] Turning briefly to FIG. 1B, in this illustrated embodiment, a separate ozone inlet 195 and a separate reactor air inlet 137 are defined in the reactor housing. The ozone inlet 195 receives ozone and directs it to the reactor chamber 134, and the reactor air inlet 137 separately receives air from the first air outlet 118a and directs it to the reactor chamber 134.

[0093] Returning to FIG. 1A, in the illustrated example, the first electrode 120a is positioned fluidly downstream from the first air inlet 116a and fluidly upstream from the first sample collector 122a. Similarly, the second electrode 120b is positioned fluidly downstream from the second air inlet 116b and fluidly upstream from the second sample collector 122b.

[0094] In an example aspect, the first electrode 120a and the second electrode 120b each define therein one or more air openings. In some cases, the first electrode and the second electrode each comprise an air-permeable mesh.

[0095] With reference to FIG, 3, in the illustrated embodiment the first air inlet 116a comprises a first inlet tube that has a first end 117a positioned external to the first chamber 114a and a second end 119a positioned within the first chamber. In some embodiments, the first electrode 120a can be positioned on the second end 119a of the first inlet tube. Similarly, the second air inlet 116b comprises a second inlet tube that has a first end 117b positioned external to the second chamber 114b and a second end 119b positioned within the second chamber 114b. The second electrode 120b can be positioned on the second end 119b of the second inlet tube.

[0096] In some embodiments, the first electrode120a can be electrostatically charged to have a negative charge, and the first sample collector 122a can be charged to have a positive charge, so that the first electrode 120a and the first sample collector 122a have opposite charges. Alternatively, the first electrode 120a can be electrostatically charged to have a positive charge, and the first sample collector 122a can be charged to have a negative charge. The first electrostatic field 121a is formed between the first electrode 120a and the first sample collector 122a. As aerosols containing nuclides (e.g., radionuclides) in air passing through or passing by the first electrode 120a, the aerosols travel through the first electrostatic field 121a and are directed to and deposited onto the first sample collector 122a. A similar electrical configuration and operation applies to the second electrostatic precipitator 115b, which creates the second electrostatic field 121 b between the second electrode 120b and the second sample collector 122b.

[0097] In operation, air A1 (e.g., such as from the ambient environment) enters apparatus 100 via the first air inlet 116a. Air A1 flows past or through the first electrostatic precipitator 115a. Aerosolized nuclides, including radionuclides, travel through the first electrostatic field 121a and are deposited onto the first sample collector 122a. In some embodiments, aerosols containing nuclides are charged by the first electrode 120a and migrate to the first sample collector 122a due to the first electric field 121a. In some embodiments, over 98% of the aerosolized nuclides in air A1 may be captured by the first sample collector 122a.

[0098] Air A2, from which some aerosols containing nuclides have been removed - but not necessarily gas-phase nuclides present in air A1 , including iodine gas-phase nuclides - flows out the first outlet 118a and into the reactor air inlet 136. Ozone O3flows into the ozone inlet 194 and into the reactor air inlet 136. Gas-phase iodine nuclides in air A2 and ozone O3react with each other in the reactor chamber 134. In an example embodiment, the product of the reaction is a type of oxide aerosol. In some cases, air A2 includes iodine gas that was not captured by the sample collector 122a. The reaction chamber 134 facilitates a reaction between the ozone O and the iodine gas within air A2, to generate iodine oxide aerosol (e.g., aerosolized IOX).

[0099] Air A3 (i.e. air possibly containing iodine oxide aerosol) is output from reactor air outlet 138 and directed into the second chamber 114b via second air inlet 116b. Aerosols present in air A3, including aerosolized iodine oxides, travel through the second electrostatic field 121 b and are deposited onto the second sample collector 122b. Air A4, from which some aerosolized nuclides (e.g., the aerosolized iodine oxides) have been removed, flows out the second outlet 118b, e.g. into the ambient environment. In some embodiments, most of the aerosolized iodine oxides in air A3 may be captured by the second sample collector 122b. In some embodiments, over 95% of the aerosolized iodine oxides in air A3 may be captured by the second sample collector 122b.

[0100] In this way, aerosols containing radionuclides that are present in sampled air (e.g., ambient air) can be captured using the first sample collector 122a. For radionuclide gases that are not captured by the first sample collector 122a, the reaction with ozone generates aerosolized oxides that can be captured by the second sample collector 122b. In a particular example aspect, gas-phase iodine nuclides that are not captured by the first sample collector 122a are reacted with ozone to generate aerosolized iodine oxides that can be captured by the second sample collector 122b.

[0101] In some embodiments, the first and the second sample collectors 122a, 122b are removable from their respective chambers 114a, 114b and can be measured with a spectrometer external to the apparatus 100. Additionally, or alternatively, sample collectors 122a, 122b can be measured using one or more on-board spectrometers.

[0102] Referring to FIG. 2, in the illustrated example a first spectrometer system 202a is positioned within the first chamber 114a to measure the sample of nuclides (e.g., radionuclides) collected by the first sample collector 122a. Alternatively, spectrometer system 202a may be positioned sufficiently close to the first sample collector 122a while being external to the first chamber 114a.

[0103] Similarly, a second spectrometer system 202b is positioned within the second chamber 114b to measure the sample of nuclides (e.g., radionuclides) collected by the second sample collector 122b. Alternatively, spectrometer system 202b may be positioned sufficiently close to the first sample collector 122b while being external to the second chamber 114b.

[0104] In some embodiments, the first and the second spectrometer systems 202a, 202b each include a gamma spectrometer configured to detect radionuclides.

[0105] Each of the spectrometer systems 202a, 202b may include a radiation shield for blocking gamma radiation. Such radiation shields may include collimators.

[0106] In the apparatus 100 illustrated in FIG. 2, an optional fan or blower 230 is positioned downstream from the second air outlet 118b and is fluidly connected to the second air outlet 118b. Fan 230 is configured to move air at least through: the first air inlet 116a, the first chamber 114a, the first air outlet 118a, the reactor air inlet 136, the reactor chamber 134, the reactor air outlet 138, the second air inlet 116b, the second chamber 114b, and the second air outlet 118b.

[0107] In another example aspect, the apparatus 100 includes a power and control subsystem 240. In the illustrated example, subsystem 240 includes a computer 210, a high voltage power system 220, and a main power system 222. Main power system 222 provides electrical power to the computer 210 and to the high voltage power system 220. Computer 210 includes data acquisition hardware, memory, and a processor. In some cases, computer 210 includes a network interface to provide real-time (or near-real-time) communication over a network, such as a cell phone network, Wi-Fi network, satellite network, a wired network, or a combination thereof. Computer 210 is configured to control the spectrometer systems 202a, 202b via communication wires 204a and 204b, and to collect data from the spectrometer systems. Computer 210 also controls fan 230 via control wires 231. In some embodiments, computer 210 is also configured to control the high voltage power system 220. The high voltage power system 220 is configured to selectively generate a high voltage difference between the first electrode 120a and the first sample collector 122a (via wires 212a and 214a) to generate the first electrostatic field 121a. Similarly, the high voltage power system 220 is configured to selectively generate a high voltage difference between the second electrode 120b and the second sample collector 122b (via wires 212b and 214b) to generate the second electrostatic field 121 b.

[0108] In some embodiments, the components of the apparatus 100 are enclosed within an optional housing 232.

[0109] In some embodiments, computer 210 also controls the ozone generator 190 (e.g., over data wires 217). In some cases, computer 210 is configured to control the amount ofozone generated. For example, computer 210 may be configured to turn ozone generator 190 on or off. Additionally, or alternatively, computer 210 may be configured to adjust the flowrate of air through ozone generator 190 to change the ozone generation rate. In some cases, the computer may be configured to control when ozone is flowed into the reaction chamber 134, and when no ozone is supplied to the reaction chamber 134. For example, computer 210 may be configured to open and / or close one or more valves or other flow control devices (not shown) positioned between ozone generator 190 and reaction chamber 134.

[0110] In some embodiments, computer 210 is configured to compare aerosol / particle iodine data collected from the first spectrometer system 202a to gas-phase iodine data collected from the second spectrometer system 202b. Such a comparison may indicate how much iodine is actually in the gas phase, which may be considered relevant for understanding the impact of iodine in the sampled ambient air. For example, iodine in a gas state has a higher inhalation dose coefficient according to standards established by the International Commission on Radiation Protection.

[0111] In some embodiments, computer 210 is configured to analyze data from the second stage (i.e., as detected by the second spectrometer system 202b) as compared to data from the first stage (i.e., as detected by the first spectrometer system 202a) to compute and output an efficiency of the first stage vs the second stage. For example, the collection / capture efficiency of the first stage is unlikely to be 100% efficient. However, an efficiency for the first stage can be determined by e.g., analyzing how much of other radionuclides in the sample are captured on the second filter. For example, at Fukushima, cesium was always detected. By determining how much cesium is collected / captured by the second stage relative to the first stage, an actual efficiency for the first stage can be calculated. If, for example, from cesium measurements it is determined that 2.1% of the aerosols pass through the first stage without being collected / captured. This calculated efficiency can then be used as a correction factor when determining how much of the iodine collected / captured in the second stage was actually from the gas phase.

[0112] FIG. 3 illustrates an isolated view of an electrostatic precipitator subsystem 110, which is representative of the first and the second electrostatic precipitator subsystems 110a, 100b. Subsystem 110 includes a spectrometer system 202. The sample collector 122 includes a deposition sheet that comprises a first deposition surface 350 and an opposite-facing surface 352. In the illustrated example, the first deposition surface 350 faces the electrostatic precipitator 120 and the opposite-facing surface 352 faces the spectrometer system 202.

[0113] In the illustrated example, an air gap 302 between the spectrometer system 202 and walls of the housing 112 facilitates airflow within the chamber 114 and around the sample collector 122 and the spectrometer system 202.

[0114] FIG. 4A illustrates a perspective view of an electrostatic precipitator subsystem 110 according to another example embodiment, which is representative of the first and the second electrostatic precipitator subsystems 110a, 100b. In the illustrated example, a deposition sheet (which functions as a sample collector 122) and a spectrometer system 202 are insertable into the housing 112. The cross-sectional view taken along the line 400A-400A in FIG. 4A is shown in FIG. 4B. FIG, 4B illustrates the spectrometer system 202 and the sample collector 122 positioned within the housing 112.

[0115] Referring to both FIGs. 4A and 4B, in the illustrated example the spectrometer system 202 is fluidly isolated from the chamber 114. The housing 112 comprises a recess structure 402 that protrudes inwardly into the chamber 114 and defines therein a recess 404 that is fluidly separated from the chamber 114. The recess structure 402 comprises an opening 408, and the spectrometer system 202 is positioned within the recess 404 and is removable and insertable via the opening 408. As shown in FIG. 4B, an air gap 440 is defined between the recess structure 402 and the at least one wall of the housing 112 to facilitate airflow within the chamber 114 around the recess structure 402.

[0116] In an example embodiment, the spectrometer system 202 includes a gamma spectrometer that is housed within a shield 410. The shield 410 is configured to inhibit or prevent background radiation fields from interfering with the spectrometer. Such background radiation fields may arise from contamination of the ground surrounding the detection apparatus, or from the other electrostatic precipitator subsystem. Shield 410 may be made of tungsten or another type of radiation blocking material. Optionally, shield 410 includes at least one collimator. In some embodiments, the shield 410 includes three collimators. For example, the collimator may be a specific type of opening in the shield.

[0117] The housing 112 illustrated in FIG. 4A further includes a sheet inlet 406 through which the deposition sheet (which functions as a sample collector 122) can enter into the chamber 114. In some embodiments, the sheet inlet 406 is sealable to inhibit or prevent airflow through the inlet. For example, a seal that reduces airflow may be positioned over the sheet inlet 406. In some embodiments, the seal may be a sealing mechanism configured to selectively seal the sheet inlet 406 to reduce or prevent airflow through the sheet inlet 406, and to selectively provide an opening to the sheet inlet 406 to allow movement of the deposition sheet through the sheet inlet 406. The deposition sheet (which functions as asample collector 122) can be inserted into and removed from the chamber 114 via the sheet inlet 406.

[0118] In some examples, the sealing mechanism is an inflatable seal that is configured to selectively seal the sheet inlet 406 and to selectively provide an unsealed opening to the sheet inlet 406. It will be appreciated that other types of sealing mechanisms can be used in alternative embodiments.

[0119] In some embodiments (not shown), housing 112 further includes a separate sheet outlet through which a deposition sheet can exit the chamber. The sheet inlet and the first sheet outlet may be positioned on opposite-facing walls of the housing. In this way, a deposition sheet, acting as a sample collector 122, can be inserted into chamber 114 via the sheet inlet 406 and can be removed from the chamber 114 via the sheet outlet. In some cases, a seal that reduces airflow may be positioned over the sheet outlet.

[0120] In some embodiments, the sealing mechanisms at the sheet inlet and sheet outlet may be controlled by computer 210 or by a separate controller (not shown).

[0121] In some embodiments, the sheet inlet and the sheet outlet are not sealed.

[0122] Turning to FIG. 5A, another example embodiment of an apparatus 100 is illustrated, in which the sample collector is part of a film exchange roller system.

[0123] In the illustrated example, a first deposition sheet (which functions as a first sample collector 122a) is a portion of a first flexible deposition film 504a. The first electrostatic precipitator subsystem 110a further comprises a first film exchange roller system 502a that includes a first roller 506a that is operable to pull the first deposition sheet through a first sheet inlet 510a defined in the first housing 112a, into the first chamber 114a, and out the first chamber 114a through the first sheet outlet 512a. Similarly, the second deposition sheet, which is the second sample collector 122b, is a portion of a second flexible deposition film 504b. The second electrostatic precipitator subsystem 110b further comprises a second film exchange roller system 502b that comprises a second roller 506b operable to pull the second deposition sheet through a second sheet inlet 510b defined in the housing 112b, into the second chamber 114b, and out the second chamber through a second sheet outlet 512b defined in the housing 112b.

[0124] The unused or fresh first deposition film 504a is stored on a first storage roller 514a. The used first deposition film 504a is stored on the first roller 506a. Similarly, the unused or fresh second deposition film 504b is stored on a second storage roller 514b. The used second deposition film 504b is stored on the second roller 506b.

[0125] In an example embodiment, the first roller 506a and the second roller 506b are selectively driven by, respectively, a first motor 508a and a second motor 508b. The first motor and the second motor are controllable by an electronic controller, e.g., by computer 210 or a separate controller.

[0126] The first sheet inlet 510a, the first sheet outlet 512a, the second sheet inlet 510b, and the second sheet outlet 512b may each include a sealing mechanism that seals the air within the first chamber 114a. The sealing mechanism can be operated, using the computer 210, to be in a sealed state or to be in an unsealed state. The sealing mechanism is preferably in a sealed state when the apparatus is drawing a sample.

[0127] In the example illustrated in FIG. 5B, the first film exchange roller system 502a is positioned within the housing 112a, and the second film exchange roller system 502b is positioned within the housing 112b. No sealing mechanisms are used in the embodiment shown in FIG. 5B.

[0128] In the example illustrated in FIG. 5C, deposition film 504 (which is an example of first and the second deposition films 504a, 504b) comprises a continuous metallic film strip, portions of which function as sample collectors 122. Put another way, different portions of the continuous metallic film strip 504 are used as different sample collectors 122.

[0129] In the example illustrated in FIG. 5D, deposition film 504 504 (which is another example of first and the second deposition films 504a, 504b) comprises a plurality of discrete metallic sheets (which function as sample collectors 122) positioned along a non-metallic tape 550 in spaced relation to each other. The portions that form a deposition sheet (which functions as a sample collector 122) each comprise one of the plurality of discrete metallic sheets.

[0130] Returning to FIGs. 5A and 5B, in some embodiments film exchange roller system 502 is configured to advance the deposition film into place in the electrostatic precipitator subsystem, store fresh deposition film, and store used deposition film. In the illustrated examples there are two sets of rollers with a fabric tape spanning between them. The deposition film includes squares of aluminum foil, and these are spaced along the fabric tape. The positions of the aluminum squares are such that, when one is in place in the electrostatic precipitator, the used ones that passed before are wound onto the used film roller. To reduce false readings in the spectrometer system, rollers may be positioned such that radiation fields originating from any collected aerosol products are shielded (and preferably completely shielded) from the gamma spectrometer by the tungsten shield 410. In the illustrated example, fabric tape passes through a pair of slits (e.g., sheet inlet and sheet outlet) in the housing ofthe electrostatic precipitator subsystem. In some cases, a sealing mechanism may be used to seal the open slits while the apparatus is drawing a sample.

[0131] In an example embodiment for controlling the motors 508a, 508b for the rollers, after the computer 210 may be configured to detect, via a spectrometer system, that a radionuclide level has reach a predetermined threshold. In response to determining that a predetermined radionuclide level has been reached, the computer 210 may be configured to control the motor to the roll of deposition film to advance a new section of the deposition film, thus replacing the deposition sheet being used as a sample collector.

[0132] In another example embodiment for controlling the motors 508a, 508b for the rollers, the computer 210 may be configured use a time-based threshold. For example, response to determining that the electrostatic precipitator and the sample collector have been charged with voltages for a cumulative predetermined time period threshold, the computer 210 may be configured to control the motor to the roll of deposition film to advance a new section of the deposition film, thus replacing the deposition sheet being used as a sample collector.

[0133] It will be appreciated that other types of logic may be stored in the memory of the computer 210 to control the motors 508a, 508b.

[0134] While some of the above examples describe the sample collector as a deposition sheet that is a flexible deposition film, the deposition sheet may alternatively be a deposition plate that is metallic and can be charged.

[0135] FIG. 6A illustrates another example embodiment of an apparatus 100. In this embodiment, apparatus 100 includes a first electrostatic precipitator subsystem 110a that is fluidly connected to a reactor subsystem 130, which is in turn fluidly connected to a second electrostatic precipitator subsystem 110b.

[0136] FIG. 6A also illustrates an example of tubing connecting the subsystems together. In the embodiment illustrated in FIG. 6A, and as more clearly seen in FIG. 6B showing an electrostatic precipitator subsystem 110 in isolation, film exchange roller system 502 is shown passing through a sheet inlet and sheet outlet, with a portion of the deposition film 504 forming a deposition sheet acting as the sample collector 122 within the chamber 114. The deposition sheet acting as the sample collector 122 is positioned above the spectrometer system 202, which is housed in a shield 410 (e.g., a tungsten shield). The shield 410 and the spectrometer system 202 are positioned within the recess 404 defined by the recess structure 402.

[0137] In the illustrated example, the electrode that forms the electrostatic precipitator 120 is attached to the bottom end 119 of the inlet tube.

[0138] Turning to FIG. 6C, an example of reactor subsystem 130 is shown in more detail. In the illustrated example, reactor housing 132 is an elongate tube and comprises one or more baffles 602, 604 positioned within the reactor chamber 134. In this example, a first baffle 602 is positioned in proximity to the reactor air inlet 136 and a second baffle 604 is positioned in proximity to the reactor air outlet 138. In some embodiments, the baffles 602, 604 are discs that define multiple small openings that promote the churning of air as it passes through the openings. It will be appreciated that other configurations of baffles suitable for disturbing the air flow within the reactor chamber 134 may be incorporated into the reactor subsystem 130.

[0139] In some embodiments, there are three main stages in the radionuclide monitoring apparatus: a first electrostatic precipitator stage, an iodine reactor stage, and a second electrostatic precipitator stage. The electrostatic precipitator stages include gamma spectrometer systems incorporated into them, as well as the deposition film exchange systems. The iodine reactor stage includes an ozone generator. Other components include a fan system to drive the flow of air through the apparatus, control systems, and monitoring systems. Optionally, the apparatus may includes a gas conditioning system to control, for example, the temperature and humidity of the air, which in some cases are parameters that affect the efficiency of the electrostatic precipitators or iodine / ozone reaction chemistry.

[0140] In another example embodiment, a radionuclide sampling apparatus includes: a first electrostatic precipitator subsystem, an iodine reactor subsystem, an ozone generator subsystem, and a second electrostatic precipitator subsystem. The first electrostatic precipitator subsystem includes a first housing defining therein a first chamber, a first air inlet of the first chamber, a first air outlet of the first chamber, a first electrostatic precipitator positioned within the first chamber, a first sample collector positioned within the first chamber, and a first gamma spectrometer system configured to detect a first sample of radionuclides collected at the first sample detector. The iodine reactor subsystem includes a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, and a reactor air outlet of the reactor chamber. The ozone generator subsystem includes an ozone generator and an ozone outlet. The second electrostatic precipitator subsystem includes a second housing defining therein a second chamber, a second air inlet of the second chamber, a second air outlet of the second chamber, a second electrostatic precipitator positioned within the second chamber, a second sample collector positioned within the second chamber, and a second gamma spectrometer system configured to detect a second sample of radionuclides collected at the second sample detector. The reactor air inlet is fluidly connected to the first air outlet and the ozone outlet, and the reactor air outlet is fluidly connected to the second air inlet. The reactor chamber receives ozone outputted from the ozone generator and iodine gas- ZZ -outputted from the first air outlet, facilitates a reaction between the ozone and the iodine gas to generate iodine oxide aerosol, and outputs the iodine oxide aerosol to the second chamber.

[0141] Example Operating Envelope for Radionuclide Monitoring

[0142] The main value of interest is typically the airborne activity concentration ca iof different radionuclides, and these would be expected to be observed with concentrations in the range of 1-104Bq / m3. The gamma spectrometers used in a monitoring system measure a physical count rate of a species C(, which is related to the activity of species i collected on the deposition surface Af)iby the detection efficiency et:

[0143] The collected activity is a function of the volumetric flow rate of air F, the capture efficiency C , and the amount of time that the deposition surface has been used. In addition, the activity of the deposition surface is also subject to radioactive decay, based on the decay constant . As such, the count rate relates to the air concentration by:

[0144] For radionuclides with half-lives much greater than the collection time, such that

[0145] Increasing the capture efficiency and detector efficiency positively impact the sensitivity of the overall system. Laminar-flow electrostatic precipitators can theoretically achieve 100% aerosol collection efficiency as long as all aerosols are charged by the corona and the collection area is large enough. The detector efficiency is limited by the geometric view factor between the collected radioactivity and the semi-conductor crystal in the gamma spectrometer, and can be optimized by allowing the material to collect as close as possible to the detector. Likewise, increasing either the flow rate or the collection time is also expected to improve the performance of the apparatus, although these come with additional drawbacks. For example, increasing the flow rate of the apparatus increases the power requirements, and also decreases the residency time for aerosol collection requiring higher electric fields or larger collection surfaces. Increasing the collection time increases the average activity on the detector, allowing detection of lower activity at the expense of the temporal resolution the system.

[0146] Another factor positively impacting the effectiveness of the overall system is the ability, in some embodiments, to automatically change the deposition surface, and periodically replace it with a fresh one, as this can help improve the sensitivity, and can allow for continuous monitoring of an area.

[0147] In some embodiments, air flow rates of around 10 L / min in the electrostatic precipitator are employed. The flow rate is preferably optimized for the expected range of outdoor concentrations in the ambient environment in which the apparatus is (or is expected to be) used. In some cases, flow rates below ~ 10 L / min may not collect enough radioactivity in order to be detectable with the desired temporal resolution, and higher flow rates risk overwhelming and saturating the detector should high concentration radioactivity releases be observed.

[0148] In some embodiments, apparatus 100 may be operated such that a deposition sheet (which acts as a sample collector 122) is changed frequently (e.g. about every 10 minutes, every 20 minutes, every 30 minutes, every 40 minutes, every 50 minutes, or every hour) during an emergency, when airborne concentrations of radioactive species are expected to be high. In some embodiments, apparatus 100 may be operated such that the deposition sheet (which acts as a sample collector 122) is changed less frequently (e.g. about every 12 hours, or every 24 hours) during routine monitoring.

[0149] In some cases, computer 210 includes control logic to automatically adjust the air flow rates and counting times based on observed count rates. For example, if the detected count activity is low, the computer 210 may be configured to adjust one or more systems to operate at higher air flow rates and to operate the spectrometer system at longer counting times to improve the lower detection limit. As another example, in a high activity environment, the computer 210 may be configured to adjust the air flow rate to be lower or reduced, and adjust the count times of the spectrometer systems to be lower or reduced to avoid saturating the gamma detector.

[0150] Electrostatic Precipitator Subsystem

[0151] The electrostatic precipitator collects aerosols by using electrostatic fields. There are two main steps in the process: first the aerosols become charged by running them through a coronal discharge and, second, the aerosols are collected as they pass through a large electric field where the charged aerosols are attracted to the deposition surface.

[0152] The purpose of the electrostatic precipitator stages are to remove the radionuclides from the air and collect them near the gamma spectrometer system so that their activity can be measured. The first electrostatic precipitator stage is meant to collect radionuclides that exist as atmospheric aerosols. The second electrostatic precipitator stage is meant to collectiodine gas that was in the atmosphere, and was converted into IOXaerosols in the iodine reactor.

[0153] In an example airflow model shown in FIG. 7, which shows a quarter-cut-away view of an electrostatic precipitator, the sample collector was modelled as 4.5 cm x 4.5 cm, the housing walls was modelled at 1 cm thickness, the air inlet was modelled with an internal radius of 1 cm, the electrode of the electrostatic precipitator was modelled as a spherical radius of 2.2 cm, the spacing between the electrode of the electrostatic precipitator and the deposition sheet was modelled at 0.75 cm, and the outlet channel flowing around the deposition sheet was modelled at a width of 1 cm. The model assumed laminar, incompressible air flow. No slip boundary conditions were applied to the interior walls of the model. A fully developed flow condition with a volume flowrate of 10 L / min was applied at the inlet surface.

[0154] In an example electrostatic model shown in FIG. 8, a high voltage cable fixed to one side of the air inlet tube is connected to a spherical cap electrode made of a conductive mesh which allows air to flow through it. A rectangular or square sample collector (e.g., a plate or a deposition sheet) is placed below the air inlet and connected to a second high voltage supply of the opposite polarity to the spherical cap. The radiation detector is positioned below the collector plate inside electrical insulation and tungsten shielding, which is also electrically grounded. The electric potential, <t>, in the air and polyethylene (assuming the precipitator walls are 1 cm thick polyethylene) may be calculated by:-V ■ 606rVO> = pv(4)

[0155] Here, e0is the vacuum permittivity, eris the relative permeability in air and polyethylene, and pvis the space charge density. Calculation of the space charge density due to coronas is difficult due to the non-linearity and the potential for multiple charge carriers that may interact with each other and the aerosols. Alternatively, electrical potential may be estimated neglecting any space charges (v= 0) to provide initial estimates. In FIG. 8, the approximated electric potential is shown for electrode voltages of ±10 kV. In other words, in some case when operating the electrostatic precipitator subsystem, there can be a voltage difference of 20 kV between the electrode of the electrostatic precipitator and the surface of the sample collector 122.

[0156] If the magnitude of the electric field is sufficiently high, charge carriers can be accelerated sufficiently to cause ionization of some molecules, creating a region of partial ionization. If this region extends between conductors at different voltages, electrical breakdown can occur leading to an electrical arc. However, if the high electrical field region issurrounded by a region of lower electric fields that is insufficient to cause breakdown, then a stable corona may form. Utilizing this simple model of coronas, it is desired that the electrostatic precipitator be operated at a high enough voltage to create a corona that envelops the electrode, but does not extend to the surface of the sample collector 122 plate.

[0157] Spectrometer System

[0158] For the application of radionuclide monitoring, the spectrometer system includes a gamma spectrometer. In some cases, a cadmium zinc telluride (CZT) semiconductor-based gamma spectrometer can be used, as it has desirable spectral resolution, is more compact than sodium iodide scintillator detectors, and can operate at room temperature without the need for cryogenics (as is the case for germanium-based detectors). In some examples, CZT detectors are small in size, with crystals on the order of 1 cm3, and the whole system being about 2 cm by 2 cm by 5 cm, with power and communication being provided through a USB cable. It will be appreciated that other types of gamma detectors can be used.

[0159] In some examples, spectrometer system 202 may be a CSM-GR1™ spectrometer system provided by Miron Technologies, Inc. It will be appreciated that other types of spectrometer systems suitable for detecting radionuclides according the principles described herein may be used in alternative embodiments.

[0160] Reactor Subsystem

[0161] In some embodiments, reactor subsystem 130 is configured specifically for iodine reactions - i.e. to convert iodine gas into IOXparticles, which can then be collected in the second electrostatic precipitator stage. This can be done through the reaction with ozone supplied from an ozone generator. The reactor chamber is configured to provide enough contact time between the two reactants for an adequately large conversion fraction to occur.

[0162] In reactor subsystem 130, air that has passed through the first electrostatic precipitator is mixed with an ozone stream, and the air / ozone mixture is introduced to the reaction chamber. In some embodiments, the reactor housing 132 is oriented vertically and the reactor air inlet 136 is positioned at the bottom of the reactor housing and the reactor air outlet 138 is positioned at the top of the reactor housing. In some examples, the reactor housing 132 may be a glass tube having a diameter of about 150 mm, and a length of about 600 mm. Polytetrafluoroethylene (PTFE) end caps may be positioned on both ends of the glass tube, as well as PTFE baffle plates near the inlet and outlet in order to promote an even distribution of the ozone concentration and flow profile.

[0163] It is expected that the corona discharge in the first electrostatic precipitator stage will produce some ozone, but the concentrations will not likely be high enough for the IOXproduction reactions to proceed fast enough. As such, an ozone generator may be used to augment the ozone concentration. For example, there may be an ozone input rate of 0.8 g / h from the ozone generator, and the operating concentration of ozone in the reactor chamber 134 may be about 650 ppm. This sort of production level is possible with a laboratory-scale ozone generator that uses air (as opposed to pure O2 gas) as the feed gas.

[0164] The concentration of iodine along the length of the reactor chamber, as a function of residence time T , can be calculated according to the following equation, assuming that the ozone concentration will be enough in excess that it will be approximately constant.[I2] = [l2]oe -k [0^ (5)

[0165] By way of background, after the Fukushima accident, the maximum concentrations that were observed were on the order of 104Bq / m3, which is a mole fraction of approximately 4x1 o-16in air. The residence time is the ratio of the reactor volume and the volumetric flow rate through the reactor chamber, as given by:_ V (6)TF

[0166] The reactor volume required to achieve a 95% conversion of iodine to IOXspecies, with a volumetric flow rate of 10 L / min and a temperature of 283 K, would be approximately 10.3 L. The example dimensions of the reactor housing noted above (e.g., a tube with a 150 mm diameter, and a 600 mm length) achieve this. Baffles 602, 604 installed within the reactor housing cause the air flow to spread out evenly throughout the full width of vessel. In an example embodiment, each baffle includes eighteen holes, that are each 12 mm in diameter.

[0167] The nuclide sampling apparatus 100 may be adapted or modified for other types of detection, such as detecting bromine, halides, chlorine, nitrogen, volatile organic compounds (VOCs), chlorofluorocarbons (CFCs), or the like. It is likely that a spectrometer or a different type of detector would be required to detect these other types of compounds.

[0168] In another example embodiment, an apparatus does not include the first electrostatic precipitator subsystem. In other words, air A1 from the environment is passed into the reaction chamber 134 along with ozone O3. Air A3 exiting the reaction chamber 134 is then passed through electrostatic precipitator 120b for sampling on the second sample collector 122b. In other words, there is only one stage of electrostatic sampling, which occurs after the ozone-iodine reaction in reactor subsystem 130.

[0169] For example, FIGs. 9A and 9B illustrate an example embodiment of an apparatus 900. Apparatus 900 includes a reactor subsystem 130 positioned upstream from a single electrostatic precipitator subsystem 110. The computer 210, or another controller, is configured to control the ozone generator 190 (e.g. activate ozone generation and deactivate ozone generation). In a first operating mode in which there is no ozone reaction (as illustrated in FIG. 9A), air A1 is passed into apparatus 900 and through the reactor subsystem 130 without any ozone reaction. In the first operating mode, ozone generator 190 is controlled to not provide any ozone to the reaction chamber. For example, the ozone generating function of the ozone generator 190 may be turned off. Air A1 is then passed into the electrostatic precipitator subsystem 110 and radionuclides are collected on the sample collector 122 for measurement by spectrometer system 202. This produces a spectrometer measurement in the first operating mode. Air A5, which has at least a portion of the radionuclides removed from air A1 , exits the apparatus 900.

[0170] In a second operating mode, illustrated in FIG. 9B, the ozone generator 190 is controlled to generate ozone and provide the ozone to the reaction chamber 134. Air A1 and ozone O3flow into the reaction chamber 134 and chemically react to produce aerosolized iodine oxides. Air A7 exiting the reaction chamber 133 includes at least a portion of the radionuclides from air A1 that did not react with the ozone and the aerosolized iodine oxides. The radionuclides from air A1 that did not react with the ozone and the aerosolized iodine oxides pass into the electrostatic precipitator subsystem 110, and are collected on the sample collector 122 for measurement by spectrometer system 202. This produces a spectrometer measurement in the second operating mode. Air A8, which has most of the radionuclides from air A1 that did not react with the ozone and the aerosolized iodine oxides removed from the air A1 , exits the apparatus 900.

[0171] In some cases, the sample collector (or deposition sheet) 122 is refreshed between the first operating mode and the second operating mode. For example, a first instance of a sample collector is used in the first operating mode, and a second instance of the sample collector is used in the second mode. In this way, a radionuclide measurement from the spectrometer system 202 in the first operating mode and a radionuclide measurement from the spectrometer system 202 in the second operating mode are considered distinct from each other. In some examples, such as shown in FIGs. 9A and 9B, film exchange roller system 502 may be used to refresh or change from a first instance of a sample collector (e.g., a first deposition sheet) to a second instance of a sample collector (e.g., a second deposition sheet). In some other cases the apparatus 900 may be operated in the first operating mode followed by the second operating mode, with the same instance of the sample collector (or deposition sheet if used) used for both the first operating mode and the second operating mode.

[0172] The computer 210 is configured to compute a difference between the spectrometer measurement in the second operating mode and the spectrometer measurement in the first operating mode to determine (and preferably store) a gas-phase iodine measurement for air A1.

[0173] The apparatus may be operated in the first operating mode for a given time period, and operated in the second operating mode for another given time period. The given time periods for the first operating mode and the second operating mode may be different from each other. Preferably, the first operating mode and the second operating mode are implemented in succession. For example, the first operating mode is implemented for a first time period, and immediately (or shortly) afterwards, e.g. within a predetermined intermediate time period, the second operating mode is implemented fora second time period. Alternatively, the second operating mode may be implemented for a first time period, and immediately (or shortly) afterwards, e.g. within a predetermined intermediate time period, the first operating mode may be implemented for a second time period.

[0174] The process described with respect to FIGs. 9A and 9B assumes that the amount and type of radionuclides in air A1 does not significantly change between the time period of the first operating mode and the time period of the second operating mode.

[0175] In some embodiments, during the first time period, the first measurement is made using a first deposition surface as the sample collector, and during the second time period, the second measurement is made using a new second deposition surface as the sample collector. For example, the first deposition surface can be characterized as ‘used’ as it has already collected radionuclides during the first operating mode. Continuing with the example, the second deposition surface can be characterized as ‘new as it has not yet been used to collect radionuclides, and the second deposition surface is then positioned relative to the electrostatic precipitator to collect radionuclides during the second operating mode.

[0176] In some cases, the second deposition surface replaces the first deposition surface as the sample collector before the second measurement is collected. In some cases, the computer 210 is configured to detect that the second deposition surface has replaced the first deposition surface as the sample collector before the computer controls the ozone generator to operate in the second operating mode. In some cases, the detection of the replacement of the first deposition surface with the second deposition surface includes the computer 210 controlling the replacement of the second deposition surface to replace the first deposition surface. For example, this can be done by controlling the film exchange roller system 502 or another mechanism for replacing deposition surfaces. In some embodiments, the detection of the replacement of the first deposition surface with the second deposition surface includes theuse of a sensor (not shown) positioned within the electrostatic precipitator subsystem 110 and operatively connected to the computer 210. In some cases, the sensor is a presence sensor, an optical sensor, a mechanical sensor, or a combination thereof. In some cases, the detection of the replacement of the first deposition surface with the second deposition surface includes the computer 210 receiving a data message or signal, such as from another device, that may be automatically generated or provided responsive to a person’s (i.e., operator) input.

[0177] In another example embodiment, a detection apparatus includes two parallel stages. For example, FIG. 10 illustrates an example embodiment of an apparatus 1000. (For clarity, power lines from power system 220 and communications lines from computer 210 to the first stage components are not shown in FIG. 10.) In the illustrated example, a first stage includes the first electrostatic precipitator subsystem 110a. A second stage includes the reactor subsystem 130 with its reactor air outlet 138 fluidly connected to the second air inlet 116b of the second electrostatic precipitator subsystem. The first stage and the second stage are configured to be fluidly parallel to each other. In other words, air A1 from the environment can be drawn into the first air inlet 116a of the first electrostatic precipitator subsystem 110a and air A1 from the environment can also be drawn into the reactor air inlet 136 of the reactor air subsystem 130. Air A9 leaving the first air outlet 118a of the first electrostatic precipitator subsystem 110a and air A8 leaving the second air outlet 118b of the second electrostatic precipitator subsystem 110b are both vented to the environment.

[0178] In some embodiments, computer 210 may be configured to calculate a gas-phase iodine amount by determining the difference between a detected iodine amount in the first stage (i.e., by electrostatic precipitator subsystem 110a) and a detected iodine amount in the second stage (i.e., by electrostatic precipitator subsystem 110b).

[0179] The systems, methods, and apparatus described herein may be implemented as a combination of hardware or software. In some cases, the systems, methods, and apparatus described herein may be implemented, at least in part, by using one or more computer programs, executing on one or more programmable devices including at least one processing element, and a data storage element (including volatile and non-volatile memory and / or storage elements). The apparatus may also include at least one input device (e.g., a pushbutton keyboard, mouse, a touchscreen, and the like), and at least one output device (e.g., a display screen, a printer, a wireless radio, and the like) depending on the nature of the device.

[0180] Various apparatuses, subsystems or processes have been described to provide examples of embodiments of the claimed subject matter. No such example embodiment described limits any claim and any claim may cover processes or subsystems or apparatuses that differ from those described. The claims are not limited to apparatuses or systems orprocesses having all the features of any one apparatus or system or process described above or to features common to multiple or all the apparatuses or systems or processes described above. It is possible that an apparatus or system or process described above is not an embodiment of any exclusive right granted by issuance of this patent application. Any subject matter described above and for which an exclusive right is not granted by issuance of this patent application may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such subject matter by its disclosure in this document.

[0181] It will also be appreciated that different components and different example aspects from different embodiments described herein can be combined together according to the principles described herein, even though such a combination may not be explicitly stated in relation to a particular example embodiment.

[0182] For simplicity and clarity of illustration, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth to provide a thorough understanding of the subject matter described herein. However, it will be understood by those of ordinary skill in the art that the subject matter described herein may be practiced without these specific details. In other instances, well- known methods, procedures, and components have not been described in detail so as not to obscure the subject matter described herein.

[0183] As used herein, the wording “and / or” is intended to represent an inclusive-or. That is, “X and / or Y” is intended to mean X or Y or both, for example. As a further example, “X, Y, and / or Z” is intended to mean X or Y or Z or any combination thereof.

[0184] Terms of degree such as "substantially", "about", and "approximately" as used herein mean a reasonable amount of deviation of the modified term such that the result is not significantly changed. These terms of degree may also be construed as including a deviation of the modified term if this deviation would not negate the meaning of the term it modifies.

[0185] Any recitation of numerical ranges by endpoints herein includes all numbers and fractions subsumed within that range (e.g., 1 to 5 includes 1 , 1.5, 2, 2.75, 3, 3.90, 4, and 5). It is also to be understood that all numbers and fractions thereof are presumed to be modified by the term "about" which means a variation of up to a certain amount of the number to which reference is being made if the result is not significantly changed.

[0186] Some elements herein may be identified by a part number, which is composed of a base number followed by an alphabetical or subscript-numerical suffix (e.g., 112a, or 112b).All elements with a common base number may be referred to collectively or generically using the base number without a suffix (e.g., 112).

[0187] While the above description provides examples of one or more apparatuses or subsystem or processes, it will be appreciated that other apparatuses or subsystems or processes may be within the scope of the accompanying claims.

[0188] To the extent any amendments, characterizations, or other assertions previously made (in this or in any related patent applications or patents, including any parent, sibling, or child) with respect to any art, prior or otherwise, could be construed as a disclaimer of any subject matter supported by the present disclosure of this application, Applicant hereby rescinds and retracts such disclaimer. Applicant also respectfully submits that any prior art previously considered in any related patent applications or patents, including any parent, sibling, or child, may need to be revisited.

[0189] While the above description provides examples of one or more apparatuses or subsystems or processes, it will be appreciated that other apparatuses or subsystems or processes may be within the scope of the accompanying claims.

Claims

Claims:

1. A nuclide sampling apparatus comprising: a first electrostatic precipitator subsystem comprising a first housing defining therein a first chamber, a first air inlet of the first chamber, a first air outlet of the first chamber, a first electrostatic precipitator positioned within the first chamber, and a first sample collector positioned within the first chamber; a reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, and a reactor air outlet of the reactor chamber; and a second electrostatic precipitator subsystem comprising a second housing defining therein a second chamber, a second air inlet of the second chamber, a second air outlet of the second chamber, a second electrostatic precipitator positioned within the second chamber, and a second sample collector positioned within the second chamber, wherein the first air outlet is fluidly connected to the reactor air inlet, and the reactor air outlet is fluidly connected to the second air inlet.

2. The nuclide sampling apparatus of claim 1, wherein the reactor subsystem further comprises an ozone inlet that is fluidly connected to the reactor chamber, and the ozone inlet is configured to receive ozone that flows into the reactor chamber.

3. The nuclide sampling device of claim 2, further comprising an ozone generator that is configured to provide the ozone to the ozone inlet.

4. The nuclide sampling apparatus of any one of claims 1 to 3, wherein the first electrostatic precipitator comprises a first electrode that is positioned fluidly downstream from the first air inlet and fluidly upstream from the first sample collector; and wherein the second electrostatic precipitator comprises a second electrode that is positioned fluidly downstream from the second air inlet and fluidly upstream from the second sample collector.

5. The nuclide sampling apparatus of claim 4, wherein the first electrode and the second electrode each defines therein one or more air openings.

6. The nuclide sampling apparatus of claim 4, wherein the first electrode and the second electrode each comprises an air-permeable mesh.

7. The nuclide sampling apparatus of any one of claims 4 to 6, wherein the first air inlet comprises a first inlet tube, the first inlet tube comprising a first end positioned external to the first chamber and a second end positioned within the first chamber, and the first electrode is positioned on the second end of the first inlet tube; and wherein the second air inlet comprises a second inlet tube, the second inlet tube comprising a first end positioned external to the second chamber and a second end positioned within the second chamber, and the second electrode is positioned on the second end of the second inlet tube.

8. The nuclide sampling apparatus of any one of claims 1 to 7, wherein the first electrostatic precipitator subsystem further comprises a first spectrometer system, the first sample collector comprises a first deposition sheet that comprises a first deposition surface and a first oppositefacing surface, and the first deposition surface faces the first electrostatic precipitator and the first opposite-facing surface faces the first spectrometer system; and wherein the second electrostatic precipitator subsystem further comprises a second spectrometer system, the second sample collector comprises a second deposition sheet that comprises a second deposition surface and a second opposite-facing surface, and the second deposition surface faces the second electrostatic precipitator and the second opposite-facing surface faces the second spectrometer system.

9. The nuclide sampling apparatus of claim 8, wherein the first spectrometer system is fluidly isolated from the first chamber, and the second spectrometer system is fluidly isolated from the second chamber.

10. The nuclide sampling apparatus of claim 9, wherein the first housing comprises a first recess structure protruding inwardly into the first chamber and defines therein a first recess that is fluidly separated from the first chamber, the first recess structure comprises a first opening, and the first spectrometer system is positioned within the first recess and is removable and insertable via the first opening; and wherein the second housing comprises a second recess structure protruding inwardly into the second chamber and defines therein a second recess that is fluidly separated from the second chamber, the second recess structure comprises a second opening, and the second spectrometer system is positioned within the second recess and is removable and insertable via the second opening.

11. The nuclide sampling apparatus of claim 10, wherein the first housing defines within the first chamber a first air gap between at least one wall of the first housing and the first recess structure, the first air gap configured to facilitate airflow within the first chamber around the first recess structure; and wherein the second housing defines within the second chamber a second air gap between at least one wall of the second housing and the second recess structure, the second air gap configured to facilitate airflow within the second chamber around the second recess structure.

12. The nuclide sampling apparatus of any one of claims 8 to 11, wherein the first spectrometer system comprises a first gamma spectrometer that is housed within a first shield that blocks gamma radiation; and wherein the second spectrometer system comprises a second gamma spectrometer that is housed within a second shield that blocks the gamma radiation.

13. The nuclide sampling apparatus of any one of claims 8 to 12, further comprising a computer in data communication with the first spectrometer and the second spectrometer, the computer configured to collect data from the first spectrometer system and the second spectrometer system and transmit the data via a network interface.

14. The nuclide sampling apparatus of any one of claims 8 to 13, wherein the first housing further comprises a first sheet inlet through which the first deposition sheet enters into the first chamber; and wherein the second housing further comprises a second sheet inlet through which the second deposition sheet enters into the second chamber.

15. The nuclide sampling apparatus of claim 14, wherein the first housing further comprises a first sheet outlet through which the first deposition sheet exits the first chamber, the first sheet inlet and the first sheet outlet positioned on opposite-facing walls of the first housing; and wherein the second housing further comprises a second sheet outlet through which the second deposition sheet exits the second chamber, the second sheet inlet and the second sheet outlet positioned on opposite-facing walls of the second housing.

16. The nuclide sampling apparatus of any one of claims 8 to 15, wherein the first deposition sheet is a portion of a first deposition film that is flexible, and wherein the first electrostatic precipitator subsystem further comprises a first film exchange roller system that comprises a first roller operable to pull the first deposition sheet across the first spectrometer system; and wherein the second deposition sheet is a portion of a second deposition film that is flexible, and wherein the second electrostatic precipitator subsystem further comprises a second film exchange roller system that comprises a second roller operable to pull the second deposition sheet across the second spectrometer system.

17. The nuclide sampling apparatus of claim 16, wherein the first roller and the second roller are respectively driven by a first motor and a second motor, and the first motor and the second motor are controllable by an electronic controller.

18. The nuclide sampling apparatus of claim 16 or claim 17, wherein the first deposition film comprises a first continuous metallic film strip, including the portion that forms the first deposition sheet; and wherein the second deposition film comprises a second continuous metallic film strip, including the portion that forms the second deposition sheet.

19. The nuclide sampling apparatus of claim 16 or claim 17, wherein the first deposition film comprises a plurality of discrete metallic sheets positioned in spaced relationship to each other along a first tape, and wherein the portion that forms the first deposition sheet comprises one of the plurality of discrete metallic sheets on the first tape; and wherein the second deposition film comprises a plurality of discrete metallic sheets positioned in spaced relationship to each other along a second tape, and wherein the portion that forms the second deposition sheet comprises one of the plurality of discrete metallic sheets on the second tape.

20. The nuclide sampling apparatus of any one of claims 8 to 15, wherein the first deposition sheet is a first plate; and the second deposition sheet is a second plate.

21. The nuclide sampling apparatus of any one of claims 1 to 20, wherein the reactor housing is an elongate tube and comprises one or more baffles positioned within the reactor chamber.

22. The nuclide sampling device of claim 21 , wherein a first baffle is positioned in proximity to the reactor air inlet and a second baffle is positioned in proximity to the reactor air outlet.

23. The nuclide sampling device of any one of claims 1 to 22 further comprising a fan that is positioned downstream from the second air outlet and is fluidly connected to the second air outlet, and the fan is configured to move air at least through: the first air inlet, the first chamber, the first air outlet, the reactor air inlet, the reactor chamber, the reactor air outlet, the second air inlet, the second chamber, and the second air outlet.

24. A radionuclide sampling apparatus comprising: a first electrostatic precipitator subsystem comprising a first housing defining therein a first chamber, a first air inlet of the first chamber, a first air outlet of the first chamber, a first electrostatic precipitator positioned within the first chamber, a first sample collector positioned within the first chamber, and a first gamma spectrometer system configured to detect a first sample of radionuclides collected at the first sample collector; an iodine reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, a reactor air outlet of the reactor chamber, an ozone generator subsystem comprising an ozone generator and an ozone outlet; a second electrostatic precipitator subsystem comprising a second housing defining therein a second chamber, a second air inlet of the second chamber, a second air outlet of the second chamber, a second electrostatic precipitator positioned within the second chamber, a second sample collector positioned within the second chamber, and a second gamma spectrometer system configured to detect a second sample of radionuclides collected at the second sample collector; wherein the reactor air inlet is fluidly connected to the first air outlet, and the reactor air outlet is fluidly connected to the second air inlet; wherein the ozone outlet is fluidly connected to the reactor chamber via an ozone inlet that is fluidly connected upstream to the reactor air inlet or that is fluidly connected directly to the reactor chamber; and wherein the reactor chamber receives ozone outputted from the ozone generator and iodine gas outputted from the first air outlet, facilitates a reaction between the ozone and the iodine gas to generate iodine oxide aerosol, and outputs the iodine oxide aerosol to the second chamber.

25. A radionuclide sampling apparatus comprising: a reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, and a reactor air outlet of the reactor chamber; the reactor subsystem further comprising an ozone inlet that is fluidly connected to the reactor chamber, and the ozone inlet is configured to receive ozone that flows into the reactor chamber; an ozone generator that is configured to provide the ozone to the ozone inlet; a computer in data communication with the ozone generator configured to control the ozone generator to operate in a first operating mode that generates the ozone and operate in a second operating mode that does not generate the ozone; an electrostatic precipitator subsystem comprising a housing defining therein a chamber, an air inlet of the chamber, an air outlet of the chamber, an electrostatic precipitator positioned within the chamber, a sample collector positioned within the chamber, and a spectrometer system configured to detect radionuclides collected at the sample collector; and wherein the reactor air outlet is fluidly connected to the air inlet.

26. The radionuclide sampling apparatus of claim 25, wherein in the first operating mode, the ozone flows into the reactor chamber and reacts with iodine gas in air flowing though the reactor air inlet to produce aerosolized iodine oxides.

27. The radionuclide sampling apparatus of claim 26, wherein the computer is also configured to control and communicate with the spectrometer system; wherein the computer controls the ozone generator to operate in the first operating mode for a first time period and collects a first measurement from the spectrometer system during the first time period; and wherein the computer controls the ozone generator to operate in the second operating mode for a second time period and collects a second measurement from the spectrometer system during the second time period.

28. The radionuclide sampling apparatus of claim 27, wherein, during the first time period, the first measurement is made using a first deposition surface as the sample collector; and, during the second time period, the second measurement is made using a second deposition surface as the sample collector; and, wherein the second deposition surface is new compared to the first deposition surface.

29. The radionuclide sampling apparatus of claim 28, wherein the second deposition surface replaces the first deposition surface as the sample collector before the second measurement is collected.

30. The radionuclide sampling apparatus of claim 28 or claim 29, wherein the computer detects that the second deposition surface has replaced the first deposition surface as the sample collector before the computer controls the ozone generator to operate in the second operating mode.

31. The radionuclide sampling apparatus of any one of claims 27 to 30, wherein the computer stores thereon executable instructions to compute a difference between the second measurement and the first measurement to determine a gas-phase iodine measurement in air flowing into the reactor air inlet.

32. The radionuclide sampling apparatus of any one of claims 25 to 31 , wherein the electrostatic precipitator comprises an electrode that is positioned fluidly downstream from the air inlet of the chamber and fluidly upstream from the sample collector.

33. The radionuclide sampling apparatus of claim 32, wherein the electrode defines therein one or more air openings.

34. The radionuclide sampling apparatus of claim 33, wherein the electrode comprises an air- permeable mesh.

35. The radionuclide sampling apparatus of any one of claims 32 to 34, wherein the air inlet of the chamber comprises an inlet tube, the inlet tube comprising a first end positioned external to the chamber and a second end positioned within the chamber, and the electrode is positioned on the second end of the inlet tube.

36. The radionuclide sampling apparatus of any one of claims 25 to 35, wherein the sample collector comprises a deposition sheet that comprises a deposition surface and an opposite-facing surface, and the deposition surface faces the electrostatic precipitator and the opposite-facing surface faces the spectrometer system.

37. The radionuclide sampling apparatus of claim 36, wherein the spectrometer system is fluidly isolated from the chamber.

38. The radionuclide sampling apparatus of claim 37, wherein the housing comprises a recess structure protruding inwardly into the chamber and defines therein a recess that is fluidly separated from the chamber, the recess structure comprises an opening, and the spectrometer system is positioned within the recess and is removable and insertable via the opening.

39. The radionuclide sampling apparatus of claim 38, wherein the housing defines within the chamber an air gap between at least one wall of the housing and the recess structure, the air gap configured to facilitate airflow within the chamber around the recess structure.

40. The radionuclide sampling apparatus of any one of claims 36 to 39, wherein the deposition sheet is a portion of a deposition film that is flexible, and wherein the electrostatic precipitator subsystem further comprises a film exchange roller system that comprises a roller operable to pull the deposition sheet across the spectrometer system.

41. The radionuclide sampling apparatus of claim 40, wherein the roller is driven by a motor, and the motor is controllable by the computer.

42. The radionuclide sampling apparatus of claim 40 or claim 41 , wherein the deposition film comprises a continuous metallic film strip, including the portion that forms the deposition sheet.

43. The radionuclide sampling apparatus of claim 40 or claim 41 , wherein the deposition film comprises a plurality of discrete metallic sheets positioned in spaced relationship to each other along a tape, and wherein the portion that forms the deposition sheet comprises one of the plurality of discrete metallic sheets on the tape.

44. The radionuclide sampling apparatus of any one of claims 36 to 39, wherein the deposition sheet is a plate.

45. The radionuclide sampling apparatus of any one of claims 25 to 41 , wherein the reactor housing is an elongate tube and comprises one or more baffles positioned within the reactor chamber.

46. The radionuclide sampling device of claim 45, wherein a first baffle is positioned in proximity to the reactor air inlet and a second baffle is positioned in proximity to the reactor air outlet.

47. The radionuclide sampling device of any one of claims 25 to 46, further comprising a fan that is positioned downstream from the air outlet of the chamber and is fluidly connected to the air outlet of the chamber, and the fan is configured to move air at least through: the reactor air inlet, the reactor chamber, the reactor air outlet, the air inlet of the chamber, the chamber, and the air outlet of the chamber.

48. The radionuclide sampling apparatus of any one of claims 25 to 47, wherein the spectrometer system comprises a gamma spectrometer that is housed within a shield that blocks gamma radiation.

49. A radionuclide sampling apparatus comprising: a first stage and a second stage that are configured to be fluidly parallel to each other; the first stage comprising a first electrostatic precipitator subsystem comprising a first housing defining therein a first chamber, a first air inlet of the first chamber, a first air outlet of the first chamber, a first electrostatic precipitator positioned within the first chamber, a first sample collector positioned within the first chamber, and a first spectrometer system configured to detect radionuclides collected at the first sample collector; the second stage comprising a reactor subsystem comprising a reactor housing defining within a reactor chamber, a reactor air inlet of the reactor chamber, and a reactor air outlet of the reactor chamber; the reactor subsystem further comprising an ozone inlet that is fluidly connected to the reactor chamber, and the ozone inlet is configured to receive ozone that flows into the reactor chamber; the second stage further comprising an ozone generator that is configured to provide the ozone to the ozone inlet; the second stage further comprising a second electrostatic precipitator subsystem comprising a second housing defining therein a second chamber, a second air inlet of the second chamber, a second air outlet of the second chamber, a second electrostatic precipitator positioned within the second chamber, a second sample collector positioned within the second chamber, and a second spectrometer system configured to detect radionuclides collected at thesecond sample collector, and wherein the second reactor air outlet is fluidly connected to the second air inlet of the second chamber; and a computer in data communication with the first spectrometer system and the second spectrometer system.

50. A method for using a nuclide sampling apparatus according to any one of claims 1 to 23.

51. A method for using a radionuclide sampling apparatus according to claim 24.

52. A method for using a radionuclide sampling apparatus according to any one of claims 25 to 48.

53. A method for using a radionuclide sampling apparatus according to claim 49.

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