9 results about "Neutron poison" patented technology

The invention discloses a monitoring device and an experimental device for a neutron poison layer in a spent fuel bearing device, and relates to the technical field of nuclear chemical engineering, the monitoring device comprises a first support and a second support, the bottoms of the first support and the second support are respectively provided with a moving device, and the first support and the second support are arranged in parallel at an interval; the radiation device is connected to the first support, the radiation end of the radiation device faces the second support, and the radiation end is provided with a first moderation layer; the detection device is connected to the second support, the detection device is provided with a second moderation layer, and a plurality of detectors are sequentially inserted into the second moderation layer. According to the technical scheme, the radiation device and the detection device are supported through the first support and the second support respectively, the radiation device and the detection device can move relatively through the moving device, and the monitoring device can flexibly monitor neutron poison layers at different positions of the spent fuel bearing device.

The invention discloses an automatic inhibition system for critical accidents. The system comprises a soluble neutron poison preparation subsystem, a neutron poison solution injection subsystem and a critical accident detection subsystem, the critical accident detection subsystem is electrically connected with the soluble neutron poison preparation subsystem and the neutron poison solution injection subsystem and used for detecting and judging whether critical accidents happen to target equipment or not, when it is judged that the critical accidents happen, a neutron poison solution injection instruction is automatically triggered, and the neutron poison solution is injected into the target equipment. The neutron poison solution is sent to the soluble neutron poison preparation subsystem and the neutron poison solution injection subsystem; the soluble neutron poison preparation subsystem is connected with the neutron poison solution injection subsystem and is used for preparing a neutron poison solution after receiving the neutron poison solution injection instruction and transferring the neutron poison solution into the neutron poison solution injection subsystem; and the neutron poison solution injection subsystem is used for receiving the neutron poison solution and injecting the neutron poison solution into target equipment so as to automatically inhibit critical accidents. According to the invention, critical accidents can be automatically and rapidly inhibited.

The application discloses an off-site transportation container for plutonium dioxide powder product cups, which comprises an outer container, a shock absorber, an inner container and a holder, the inner container is arranged in the outer container, the shock absorber is arranged between the inner wall of the outer container and the outer wall of the inner container, and the holder is arranged in the inner container, the inner wall of the body of the outer container is filled with heat insulation material, the shock absorber is used for buffering the vibration of the inner container, the inner wall of the body of the inner container is filled with a shielding neutron poison, and the holder is used for supporting and limiting a plutonium dioxide powder product cup hanger. The technical scheme of the application can effectively reduce the influence of vibration and thermal shock in the transportation process on the plutonium dioxide powder product cups in the container, the shock absorption performance and the heat insulation effect are good, the product transportation requirements are met, and the safe transportation of radioactive substances is ensured.

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.

The application discloses an evaporator and a PUREX process system, which comprises a heating chamber and a separation chamber, the heating chamber is an annular gap heating chamber, a feed liquid inlet and a concentrated liquid outlet are arranged on the annular gap heating chamber, a heating piece is arranged outside the heating chamber, and a hollow part is filled with a neutron poison; the bottom of the separation chamber is communicated with the top of the heating chamber, the top of the separation chamber is provided with a secondary steam outlet, and a leaching liquid inlet is further arranged on the separation chamber. The evaporator has the advantages of simple structure, large capacity, long discharge interval, low operation frequency, high purification efficiency, satisfaction of critical safety, very stable operation, realization of evaporation and concentration of plutonium-containing liquid, recovery of plutonium in a reprocessing plant and reduction of plutonium loss.

The application discloses a pressurized water reactor chemical shutdown system and method using cadmium nitrate as a shutdown solution, which comprises a chemical shutdown system and a main loop; the chemical shutdown system adopts an active or passive mode and mainly comprises a concentrated cadmium nitrate storage tank, a high-pressure injection pump and an injection pipeline; after receiving a poison emergency injection signal or a cold shutdown maintenance signal, the injection pipeline inlet valve and the outlet valve are opened, the concentrated cadmium nitrate solution is driven in an active or passive mode, is injected from the concentrated cadmium nitrate storage tank to a nuclear reactor cold end main pipeline through the injection pipeline, is further stirred in a lower chamber of a pressure vessel, and is then distributed in the pressure vessel through flow redistribution. At the same temperature, cadmium nitrate has a greater solubility and a neutron absorption cross section than traditional neutron poison boric acid; the application enhances the reliability of reactor chemical shutdown under accident conditions, improves the safety of nuclear reactor shutdown, and reduces the arrangement and maintenance costs.

The invention relates to a boron-containing extraction agent, a preparation method thereof and application of the boron-containing extraction agent in critical plutonium purification prevention, and the boron-containing extraction agent is 2, 4, 6-trimethylphenoxy-bis [2-(N, N-dioctyl acetamide)] borate. According to the method, 2, 4, 6-trimethylphenol and bis [2-(N, N-dioctyl acetamide)] boric acid are used as raw materials, and the boron-containing extraction agent is prepared through a dehydration condensation reaction between phenolic hydroxyl groups and boric acid. The neutron poison B element is introduced into the amide extraction agent to obtain the anti-criticality boron-containing extraction agent; trimethylphenoxy is introduced to a central boron atom of the boron-containing extraction agent, and the boron atom with electron deficiency in the center is protected by utilizing a hyperconjugation effect and steric hindrance, so that the water stability of the boron-containing extraction agent is improved. The boron-containing extraction agent has a high-selectivity extraction effect on plutonium, and the extraction distribution ratio of uranium, americium, strontium, cesium and other fissure elements is very low; the method is suitable for separation, purification and recovery of a large amount of plutonium in a post-treatment plant and an MOX fuel preparation plant so as to eliminate the critical risk of organic phase extraction of plutonium.

The present application relates to a concentration detection device, method, storage medium and program product. The concentration detection device includes a pulsed neutron source, a measuring tank, an attenuator, a detector and a processing device. The measuring tank contains a first solution and a neutron poison element; the pulsed neutron source is used to generate neutrons that are incident on the measuring tank; the neutrons are used to react with the nuclides generated by the first solution to generate a first gamma signal, and react with the neutron poison element to generate a second gamma signal; the attenuator is used to attenuate the first gamma signal and the second gamma signal, and output the attenuated first gamma signal and the attenuated second gamma signal to the detector; the detector is used to detect and output the attenuated first gamma signal and the attenuated second gamma signal to the processing device; the processing device is used to detect the concentration of the neutron poison element based on the attenuated first gamma signal and the attenuated second gamma signal, so that the concentration of the neutron poison element is more accurate.

A nuclear fission reactor comprising a passive thermal shut-down device, and a reactor core containing fissile fuel. The passive thermal shutdown device comprises a reservoir and a Pythagorean syphon. The reservoir is in thermal communication with the reactor core, and containing a neutron poison material which has a free surface. The Pythagorean syphon has an inlet within the reservoir, an outlet in fluid communication with the reactor core. When the neutron poison material overtops the syphon due to thermal expansion, the neutron poison material flows through the Pythagorean syphon and into the reactor core. Also provided are nuclear fission reactors having passive thermal shutdown devices using a Pythagorean syphon to control the flow of fissile fuel, neutron moderators, or neutron reflectors.