Modular pool type nuclear reactor and methods of using the same

Abstract

Example systems include modular reactor pods that can be separately shipped, delivered, and assembled at a commercial electricity generating site. Systems may include central pods that can be loaded with and house a nuclear fuel core carrying a coolant from a primary coolant flow path through the core. One or more pump pods and / or heat exchanger pods can be attached to the reactor pod post-fabrication and even post-delivery at the site. The pump and heat exchanger pods carry the continuous coolant flow path and recirculate the same into the central pod. The pods can be connected in any manner to secure the flow path in a continuous and impermeable fashion, such as by welding or hermetically sealing the pods at each point where the flow path passes between the pods.

Description

MODULAR POOL TYPE NUCLEAR REACTOR AND METHODS OF USING THE SAMERELATED APPLICATIONS

[0001] This application claims the benefit of US Provisional Application 63 / 734,289, filed December 16, 2024, the contents of which are incorporated herein by reference in their entirety.BACKGROUND

[0002] FIG. 1 is a profile cross-section of a related art liquid metal nuclear reactor 100, such as that described in co-owned U.S. Patent Publication 2022 / 0051811 to Bass et al. filed on April 19, 2021, incorporated herein in its entirety by reference. As seen in FIG. 1, a liquid metal coolant, such as liquid sodium, is heated in reactor core 102 where it rises, due to natural circulation, pump input flow, or both, to hot pool 104. The level of liquid metal is regulated to maintain gas space 106 above the liquid metal level. Liquid metal from hot pool 104 enters heat exchanger 108 and flows downward to cold pool 110 at the exit of heat exchanger 108. Intermediate pool 111 is a relatively stagnant portion adjacent cold pool 110 and partially contributes to the volume to cold pool 110. The cold liquid metal enters suction plenum 112 of primary sodium pump 114, is drawn up through primary sodium pump 114, and exits the top of primary sodium pump 114 at a high-pressure to low-pressure interface 116. High-pressure to low-pressure interface 116 is sealed against mixing with hot pool 104. High-pressure to low-pressure interface 116 inhibits mixing between hot pool 104 and cold pool 110. Internal pipe 118 carries liquid metal from cold pool 110 through high-pressure plenum 120 to reactor core 102 using primary sodium pump 114.

[0003] This background provides a useful baseline or starting point from which to better understand some example embodiments discussed below. Except for any clearly identified third-party subject matter, likely separately submitted, this Background and any figures are by the Inventor(s) or otherwise commonly owned by Applicant, created or included for purposes of this application. Nothing in this application is necessarily known or represented as prior art.SUMMARY

[0004] Example systems include modular reactor pods that can be separately shipped, delivered, and assembled at a commercial electricity generating site. Systemsmay include central pods that can be loaded with and house a nuclear fuel core carrying a coolant from a primary coolant flow path through the core. One or more pump pods and / or heat exchanger pods can be attached to the reactor pod post -fabrication and even post-delivery at the site. The pump and heat exchanger pods carry the continuous coolant flow path and recirculate the same into the central pod. The pump pod can be outfitted with an electromagnetic pump to drive the coolant, and the heat exchanger pod can be outfitted with a heat exchanger for extracting heat from the coolant and generating electricity from the extracted heat. The pods can be connected in any manner to secure the flow path in a continuous and impermeable fashion, such as by welding or hermetically sealing the pods at each point where the flow path passes between the pods.BRIEF DESCRIPTIONS OF THE DRAWINGS

[0005] Example embodiments will become more apparent by describing, in detail, the attached drawings, wherein like elements are represented by like reference numerals, which are given by way of illustration only and thus do not limit the terms which they depict.

[0006] FIG. 1 is a schematic cross-sectional profile view of a related art liquid metal nuclear reactor vessel.

[0007] FIG. 2 is a simplified, schematic cross-sectional top view of an example embodiment Shippable Modular Vessel system.

[0008] FIG. 3 is a schematic cross-sectional profile view of flow paths of an example embodiment Shippable Modular Vessel system.

[0009] FIGS. 4A and 4B are schematic cross-sectional profile views of an example embodiment electromagnetic pump pod.

[0010] FIGS. 5A and 5B are schematic cross-sectional profile views of an example embodiment intermediate heat exchanger pod in accordance with the present disclosure.

[0011] FIGS. 6A and 6B are schematic perspective views of an example embodiment external pod head collar.

[0012] FIGS. 7A and 7B are schematic perspective views of an example embodiment central pod head.DETAILED DESCRIPTION

[0013] Because this is a patent document, general broad rules of construction should be applied when reading it. Everything described and shown in this document is an example of subject matter falling within the scope of the claims, appended below. Any specific structural and functional details disclosed herein are merely for purposes of describing how to make and use examples. Several different embodiments and methods not specifically disclosed herein may fall within the claim scope; as such, the claims may be embodied in many alternate forms and should not be construed as limited to only examples set forth herein.

[0014] Membership terms like "comprises," "includes," “has,” or “with” reflect the presence of stated features, characteristics, steps, operations, elements, and / or components, but do not themselves preclude the presence or addition of one or more other features, characteristics, steps, operations, elements, components, and / or groups thereof. Rather, exclusive modifiers like “only” or “singular” may preclude presence or addition of other subject matter in modified terms. The use of permissive terms like “may” or “can” reflect optionality such that modified terms are not necessarily present, but absence of permissive terms does not reflect compulsion. In listing items in example embodiments, conjunctions and inclusive terms like “and,” “with,” and “or” include all combinations of one or more of the listed items without exclusion of non-listed items. The use of “etc.” is defined as “et cetera” and indicates the inclusion of all other elements belonging to the same group of the preceding items, in any “and / or” combination(s). Modifiers “first,” “second,” “another,” etc. do not confine modified items to any order. These terms are used only to distinguish one element from another; where there are “second” or higher ordinals, there merely must be that many number of elements, without necessarily any difference or other relationship among those elements.

[0015] When an element is related, such as by being "connected," "coupled," “on,” “attached,” “fixed,” etc., to another element, it can be directly connected to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected," "directly coupled," etc. to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0016] As used herein, singular forms like "a," "an," and "the" are intended to include both the singular and plural forms, unless the language explicitly indicatesotherwise. Indefinite articles like “a” and “an” introduce or refer to any modified term, both previously-introduced and not, while definite articles like “the” refer to the same previously-introduced term. Relative terms such as “almost” or “more” and terms of degree such as “approximately” or “substantially” reflect io% variance in modified values or, where understood by the skilled artisan in the technological context, the full range of imprecision that still achieves functionality of modified terms. Precision and non- variance are expressed by contrary terms like “exactly.”

[0017] The structures and operations discussed below may occur out of the order described and / or noted in the figures. For example, two operations and / or figures shown in succession may be executed concurrently or may be executed in the reverse order, depending upon the functional! ty / acts involved. Similarly, individual operations within example methods described below maybe executed repetitively, individually or sequentially, so as to provide looping or other series of operations aside from exact operations described below. It should be presumed that any embodiment or method having features and functionality described below, in any workable combination, falls within the scope of example embodiments.

[0018] Proportions, sizes, and shapes shown in the figures are examples for illustration. While they reflect features of some example embodiments, other relationships and magnitudes of dimensions are included in these examples. As used herein, “angular” directions substantially follow a rounded perimeter of a referenced feature, and “radial” directions substantially follow a radius of that rounded perimeter, perpendicular to the angular direction. “Vertical” and height directions substantially follow an up-down orientation, orthogonal to the radial and angular directions of a referenced feature and more likely oriented with gravity.

[0019] Related reactor designs may use a single reactor vessel that houses at least the reactor core, an electromagnetic pump, and an intermediate heat exchanger. The inventors have recognized that single-vessel designs cannot be shipped intact or largely intact to a plant location and, thus, necessitate complicated and costly on-site essential fabrication. On-site fabrication requires at least one temporary reactor fabrication building, which often rivals in size and expense compared to mandatory reactor and turbine buildings. Further, on-site fabrication of single-vessel designs requires specialized tooling, equipment, and workforce, such as a machinist, knowledge and experience, each of which may contribute to increased costs and increased startup time that may lead to a failure to meet budget and / or scheduling targets.

[0020] The inventors have further recognized that certain limitations may stem from single vessel reactor designs. Functional limitations may include operating and / or fabrication inefficiencies related to pump and intermediate heat exchanger capacity and configuration. Other limitations may include, for example, lifespan reduction of pumps and / or intermediate heat exchangers, as well as associated components, due to radiation and thermal exposure degradation.

[0021] The inventors have thus recognized multiple problems in single vessel reactor designs. To overcome these newly identified problems, as well as others, the inventors have developed example embodiments and methods described below to address these and other problems recognized by the inventors with unique solutions enabled by example embodiments.

[0022] Example embodiments include pool-type nuclear reactor vessels usable with modular functional pods. Example embodiment vessels may be a single rigid system or even single continuous piece without internal material separation, allowing both fabrication and handling of the vessel as a single article. Such vessels and pods may further be shipped in conventional trucking, railway, and barge commerce and are referred to as a Shippable Modular Vessel (“SMV”). Example embodiment SMVs may use liquid metal, such as liquid sodium or a molten salt, in a fast nuclear reactor.

[0023] Example embodiment systems include at least one of a central pod, electromagnetic pump pod (EMP pod), and intermediate heat exchanger pod (IHX pod). The pods collectively may form a primary coolant boundary of the SMV. The terms “SMV” and “SMV reactor” may be used interchangeably herein, without limitation.

[0024] As described in detail below, the EMP pod and / or the IHX pod may be external to the central pod and, upon full assembly, may be in fluid-communication with the central pod via flow paths formed through various flow ports. For example, one example embodiment system may have a central pod, one or more external EMP pods in fluid communication with the central pod, and one or more IXH pods in fluid communication with the central pod. The central pod is configured to house a reactor core. The EMP pod(s) are configured for an electromagnetic pump (EMP); and the IHX pod(s) are configured for an intermediate heat exchanger (IHX). A primary flow path maybe formed between the central pod, EMP pod(s), and IHX pod(s).

[0025] Advantageously, the SMV, either as individual, prefabricated pods or as a single, prefabricated unit, for example, if the external pods are hermetically attached to the central pod, can be fabricated off-site and delivered to a plant location by standardfreight transportation shipping methods, including by truck, rail, and barge. If shipped as individual pod components, example embodiment SMVs maybe fully assembled, such as through welding, connecting, hermetically sealing etc., at the plant location using commercially available equipment. In one or more instances, the SMV may be fully assembled within a temporary or permanent construction building, such building requiring considerably less space and expense compared to single vessel reactor fabrication buildings.

[0026] The externality of the pump and IHX pods further advantageously provides increased capacity, configuration flexibility, and increased radiation and thermal shielding capability for the component pods. Moreover, the central pod and external EMP pod(s) and IHX pod(s) maybe configured to have various lengths and diameters to facilitate various SMV configurations, capacity demands, power needs, and shipping requirements.

[0027] As shown in FIG. 2, example embodiment SMV system 200 includes central pod 202. Central pod 202 includes inner reactor vessel 207 positioned within outer central pod guard vessel 208. Guard vessel 208 maybe composed of one or more metal materials, such as stainless steel, carbon steel, and the like. Reactor vessel 207 maybe in close-fitting separation from outer central pod guard vessel 208 to prevent loss of coolant, while providing the necessary heat transfer to cool the fuel, up to necessary safety limits without power, actively-moving components, or control system actuation.

[0028] Reactor vessel 207 maybe loaded with nuclear core 205. For example, core 205 maybe a liquid sodium or other metal or molten salt-cooled core made up of several distinct fuel elements or fuel assemblies. Core 205 maybe loaded with a plurality of fuel components in a variety of shaped, such as core assemblies 203 and / or stored peripheral assemblies 204. Assemblies 203 and 204 maybe in the form of a rod, plate, tube, bundle, etc. and may include shielding materials, control materials, fuel materials, reflector materials, and / or safety or shutdown materials. Core assemblies203 may drive and control a nuclear chain reaction rate. Stored peripheral assemblies204 maybe provided within reactor vessel 207 to refuel reactor core 205, for example, to refuel assemblies 203. Fuel maybe replenished using fuel port 206. In this way, example embodiment SMV 200 may allows for increased in- vessel fuel storage capacity compared to single vessel reactor designs.

[0029] Example embodiment SMV system 200 is not limited to the aforementioned reactor components. Any suitable additional subcomponent maybe included within reactor vessel 207, such as support structures, gas expansion modules, fixed shieldingstructures, shim blades, neutron poison structures, and the like, and any one or combination thereof.

[0030] Reactor vessel 207 is configured to join to external EMP pod 210, and may join to any number of pods 210, such as EMP pods 210a and 210b which may operate in parallel or in series and be located at lateral opposing, or antipodal, locations relative to one another to facilitate load balancing or distribution across reactor vessel 207. While FIG. 2 shows two EMP pods 210a, 210b, example embodiment SMV system 200 may include a single external EMP pod 210 or greater than two external EMP pods 210.

[0031] EMP pod 210 may include outer EMP pod guard vessel 212 composed of one or more metal materials, such as stainless steel, carbon steel, and the like. Any pump structures maybe housed in guard vessel 212. For example, EMP pods 210a and 210b may each include at least one EMP that circulates cooled liquid metal (FIG. 3) from a cold pool in fluid communication with interiors 214a, 214b of EMP pods 210a, 210b. EMP pod 210 maybe cylindrical in shape and extend in a length of a longest dimension of reactor vessel 207. EMP pod 210 maybe nearly any size as a modular component that joins to reactor vessel 207. For example, EMP pod 210 maybe oversized, having significantly greater length and cross-sectional area, and thus greater capacity, compared to pump capacity in single vessel reactor designs.

[0032] Example embodiment SMV system 200 may accommodate larger diameter primary EMPs, and may accommodate supplemental pumps within EMP pods 210a, 210b. Moreover, because of the greater capacity, supplemental pumps such as relatively large diameter centrifugal pumps maybe incorporated within interiors 214a, 214b of EMP pods 210a, 210b to serve as backup to the EMPs. External EMP pods 210a, 210b may be connected, such as via hermetic attachment, and in fluid communication with, the central pod 202, forming representative flow paths 216a, 216b through specific flow ports (see FIG. 3 below).

[0033] As shown in FIG. 2, example embodiment SMV system 200 further includes external IHX pod 218, such as dual pods 218a, 218b, which may operate in parallel or in series and be located at opposing, or antipodal, locations relative to one another to facilitate load balancing or distribution across reactor 207. While two IHX pods 218a, 218b are shown, systems may use a single external IHX pod or greater than two IHX pods. IHX pods 218a, 218b may include outer IHX pod guard vessels 220a, 220b, respectively. Guard vessels 220a, 220b maybe composed of one or more metal materials, such as stainless steel, carbon steel, and the like. External IHX pods 218a, 218b maybe attached in any manner and in fluid communication with the central pod202, forming representative flow paths 216a, 216b through specific flow ports (see FIG. 3 below).

[0034] Like EMP pods 210a, 210b, IHX pods 218a, 218b may be cylindrical in shape and oversized, having significantly greater length and cross-sectional area, and thus greater capacity, compared to IXH capacity in single vessel reactor designs. Accordingly, SMV 200 may accommodate larger, rounded IHXs with larger diameters that present ease of fabrication and technology readiness compared to related kidneyshaped IHXs.

[0035] FIG. 3 is a schematic cross-sectional profile view of various flow paths within example embodiment SMV system 200 during normal operations. The flow paths described with reference to FIG. 3 are not intended to be limiting and other flow paths may exist in example embodiments. As shown in FIG. 3, example embodiment SMV system 200 may include central pod 202; external EMP pods 210a, 210b; and / or external IHX pods 218a, 218b. Each of EMP pods 210a, 210b and IHX pods 218a, 218b maybe attached to and in fluid communication with central pod 202, potentially in an hermetic, integral, or otherwise containing manner. While various components and flow paths in EMP pod 210a and IHX pod 218a are depicted in FIG. 3, the description provided herein with reference to EMP pod 210a maybe applied to EMP pod 210b, without limitation, and the description provided herein with reference to IHX pod 218a maybe applied to IHX pod 218b, without limitation.

[0036] As shown in the interiors of FIG. 3, central pod 202 may include reactor core 205 within reactor vessel 207 (FIG. 2) with fuel assemblies positioned therein. EMP pod interior 214a (FIG. 2) of EMP pod 210a includes at least one EMP 302, such as a stator-type EMP. IHX pod 222a (FIG. 2) includes at least one heat exchanger 304. EMP 302 maybe located at any position along the longitudinal length of the EMP pod 210a and heat exchanger 304 may be located at any position along the longitudinal length of the IHX pod 218a, provided that the operation of primary coolant loop described herein is not compromised.

[0037] Example embodiment SMV system 200 is configured to operate to cause liquid metal coolant 310 to circulate, as depicted by the arrows in FIG. 3. A primary coolant loop is defined by circulation of liquid metal coolant such as liquid sodium 310 between the major components of example embodiment SMV system 200. Generally, the primary coolant loop of example embodiment SMV system 200 maybe configured to circulate coolant 310 through at least a portion of the core 205 of central pod 202 to remove from core 205 heat generated due to nuclear reactions therein.

[0038] Example embodiment SMV system 200 may include hot reservoir 320, also referred to as a hot pool. Hot reservoir 320 maybe in fluid communication between central pod 202 and the IHX pod 218a. SMV may further include cold reservoir 322, also referred to as a cold pool. Cold reservoir 322 maybe in fluid communication between central pod 202 and both of IHX pod 218a and EMP pod 210a. The two reservoirs may be in fluid communication across an intermediate reservoir (not labeled), also referred to as an intermediate pool, between and adjacent to hot reservoir 320 and cold reservoir 322 within interior 222a (FIG. 2) of IHX pod 218a. Coolant may be relatively stagnant and have a temperature between the temperature of hot reservoir 320 and cold reservoir 322. The existence of an intermediate reservoir maybe avoided, for example, when example embodiment SMV system 200 includes cold reservoir 322 having a relatively larger volume compared to hot reservoir 320.

[0039] As shown in FIG. 3, example embodiment IHX pod 218a may include hot reservoir 320 in which coolant 310 exiting core 205 may circulate between core 205 and heat exchanger 304 of IHX pod 218a. “Hot” coolant 310 may circulate to IHX pod 218a and through heat exchanger 304 from core 205 through IHX pod inlet port 330 configured for fluid communication between the core 205 and IHX pod 218a. IHX pod inlet port 330 maybe located at an upper portion of IHX pod 218a, compared to IHX pod outlet 332, to receive “hot” coolant 310 (arrow) from hot reservoir 320 within core 205. IHX pod inlet port 330 is also shown in FIG. 3 with reference to IHX pod 218b. The coolant 310 received into interior 222a (FIG. 2) of IHX pod 218a is directed through heat exchanger 304. Heat exchanger 304 maybe configured to transfer heat from “hot” coolant 310 entering IHX 304 from core 205 to cold reservoir 322, also referred to as a cold pool. Cold reservoir 322 may include coolant 310 that is colder in temperature than coolant 310 forming hot reservoir 320.

[0040] As shown in FIG. 3, example embodiment SMV system 200 may include cold reservoir 322 in which coolant 310 exiting heat exchanger 304 may circulate between IHX pod 218a and EMP pod 210a through central pod 202. “Cold” coolant 310 may circulate to central pod 202 from cold reservoir 322 within IHX pod 218a through IHX pod outlet port 332. IHX pod outlet port 332 maybe located at a lower portion of IHX pod 218a, compared to IHX pod inlet port 330, to discharge “cold” coolant 310 (arrow) from cold reservoir 322 within IHX pod 218a and into reactor vessel 207 (FIG. 2) of central pod 202. Thereafter, “cold” coolant 310 may circulate to the interior 214a (FIG. 2) of EMP pod 210a from cold reservoir 322 within of central pod 202 through EMP pod lower cold port 334.

[0041] Coolant 310 entering interior 214a of EMP pod 210a through EMP pod lower cold port 334 maybe drawn upward to EMP 302. Coolant 310 from the cold reservoir 322 within reactor vessel 207 (FIG. 2) of central pod 202, composed at least partially of coolant 310 received through the IHX pod outlet port 332, circulates upward and into EMP 302. Coolant 310 maybe pumped upward through EMP 302 and circulated downward to exit EMP 302 through discharge pipe 336. Discharge pipe 336 is in fluid communication with discharge pipe outlet assembly 340, which maybe a component separate from discharge pipe 336. EMP discharge pipe outlet assembly 340 maybe configured as a L-shaped or U-shaped conduit, such as pipe or tubing, connecting back into a lower plenum or portion of reactor vessel 207.

[0042] As shown in FIG. 3, EMP 302 and reactor core 205 of central pod 202 may be in fluid communication through discharge pipe 336 and discharge pipe outlet assembly 340, where discharge outlet port extends through EMP pod lower cold port 334. Accordingly, “cold” coolant 310 maybe received by core 205 from discharge pipe 336 through discharge pipe outlet assembly 340 for cooling core 205. “Hot” coolant 310 may thereafter be received into hot reservoir 320 of central pod 202 for receipt to IHX pod 218a through IHX pod inlet port 330, thereby continuing operation of the primary coolant loop (arrows) of coolant 310.

[0043] Although various flow paths within example embodiment SMV system 200 forming the primary coolant loop during normal operations, with EMP and heat exchangers active, are described above with regard to various temperature conditions, other conditions are possible. During normal operations, example embodiment SMV system 200 may have hot reservoir 320 with a relatively high volumetric level and cold reservoir 322 with a relatively low volumetric level. In a deactivated condition, however, without pumping example embodiment SMV system 200 may provide a supplemental residual heat removal in which hot reservoir 320 and cold reservoir 322 are in or approximately in equilibrium. The supplemental coolant loop (not labeled) may include primarily annulus 350 between guard vessel 208 (FIG. 2) and reactor vessel 207 (FIG. 2) of central pod 202, direct auxiliary cooling system (DRAGS) 352, and EMP 302.DRAGS 352 may be configured to passively remove decay heat from at least a portion of core 205 heat via natural circulation, without power, labor, or control system actuation.

[0044] As part of supplemental coolant loop, coolant 310 maybe received into annulus 350 from cold reservoir 322 through one or both of IHX pod outlet port 332 and / or EMP pod lower cold port 334. DRAGS 352 maybe configured to receive coolant 310 through EMP pod upper cold port 354. Thereafter, example embodiment SMVsystem 200 maybe configured such that the coolant 310 in the supplemental coolant loop flows around (outside of) EMP 302 and circulates upward and into EMP portion 336 of EMP 302, thereby circulating as described with reference to the primary coolant loop, wherein the coolant 310 circulates downward through the discharge pipe 336 and out through discharge pipe outlet assembly 340 into central pod 202, upwards through the core 205 of central pod 202, and into the IHX pod 218a and through the IHX 304 to again arrive at coolant reservoir 322 in IHX pod 218a thereby continuing operation of the supplemental coolant loop.

[0045] Example embodiment SMV system 200 may further be equipped with a backup means for decay heat removal, such as a reactor vessel air cooling system (RVACS) employing natural draft, such as with, ambient air, cooling along all or a portion of the exterior perimeter of example embodiment SMV system 200, potentially around an external boundary of the fully assembled SMV, including the external boundaries of central pod guard vessel 208; EMP pod guard vessels 212a, 212b; and / or IXH pod guard vessels 220a, 220b (FIG. 2). In one or more instances, DRACS 352 and RVACS (not shown) may maintain an average hot reservoir 320 temperature of less than or equal to 675°C (1247°F).

[0046] In this way, example embodiment system 200 may circulate “hot” liquid metal coolant exiting the reactor core to a hot reservoir in the central pod to the IHX pod through an IHX pod inlet port; circulate the hot liquid metal coolant through a heat exchanger within the IHX pod, cooling it and directing the cold coolant to a cold reservoir in the IHX pod; circulate the cold liquid metal coolant from the IHX pod through IHX pod outlet port and back into the central pod; circulate the cold liquid metal coolant from the central pod to the EMP pod through EMP lower cold port; drive the cold liquid metal coolant through an EMP within the EMP pod to exit the EMP through a discharge pipe to the central pod through the EMP pod lower cold port; and circulate the cold liquid metal coolant back through the reactor core in the central pod to cool and remove heat from the reactor core, generating hot coolant to repeat the cycle.

[0047] FIGS. 4A and 4B, and with continued reference to FIG. 2 and FIG. 3, where like elements are denoted by like reference numerals, provided are various schematic cross-sectional profile views of elements related to EMP pod 210a according to one or more embodiments of the present disclosure. While FIGS. 4A and 4B reference EMP pod 210a, it is to be appreciated that, where not otherwise specified, the descriptionprovided herein with reference to EMP pod 210a applies to EMP pod 210b (FIGS. 2 and 3).

[0048] Referring to FIG. 4A, EMP pod 210a may include guard vessel 212a forming interior 214a. A topmost portion of the EMP pod 210a may include EMP pod head 402 permanently attached, such as by welding, to the topmost portion of the guard vessel 212a, as shown. EMP pod head 402 may include EMP head riser 404 and EMP head collar 406. EMP head collar 406 maybe used to hermetically attach and establish fluid communication between EMP pod 210a to central pod 202 (FIGS. 2 and 3).

[0049] With continued reference to FIG. 4A, guard vessel 212a is configured to form EMP pod lower cold port 334 and EMP pod upper cold port 354. In one or more instances, the EMP pod lower cold port 334 maybe configured to have a larger orifice size (i.e., allowing greater flow volume) compared to EMP upper cold port 345 to accommodate various flow path configurations (see FIG. 3). Guard vessel 212a may further be configured to form EMP pod cover gas port 410. EMP pod cover gas port 410 may be configured to prevent oxygen, air, or other contaminants from entering interior 214a of EMP pod 210a.

[0050] Interior 214a of EMP pod 210a may include EMP 302 having EMP outlet 408, discharge pipe 336, discharge pipe outlet assembly 340, and DRAGS 352. EMP 302 and central pod 202 (FIGS. 2 and 3) maybe in fluid communication through discharge pipe 336 and discharge pipe outlet assembly 340 extending through EMP pod lower cold port 334. Interior 214a may further include EMP pod shielding 420. EMP pod shielding 420 maybe composed of a shielding material (e.g., radiation, such as gamma radiation, shielding material) and configured to prevent radiation from entering the interior 214a of the EMP pod 302.

[0051] FIG. 4B shows a detailed view of a portion of EMP pod 210a. As shown in FIG. 4B, EMP discharge pipe outlet assembly 340 is in fluid communication with the bottommost portion of discharge pipe 336 (not show) and extends through EMP pod lower cold port 334. Discharge pipe outlet end 430 extends into central pod 202, as described above.

[0052] FIGS. 5A and 5B, and with continued reference to FIG. 2 and FIG. 3, where like elements are denoted by like reference numerals, provided are various schematic cross-sectional profile views of elements related to IHX pod 218a according to one or more embodiments of the present disclosure. While FIGS. 5A and 5B reference IHX pod 218a, it is to be appreciated that, where not otherwise specified, the descriptionprovided herein with reference to IHX pod 218a applies to IHX pod 218b (FIGS. 2 and 3).

[0053] Referring to FIG. 5A, IHX pod 218a may include guard vessel 220a forming interior 222a. A topmost portion of the IHX pod 218a may include IHX pod head 502 permanently attached, for example, through welding, to the topmost portion of the guard vessel 220a, as shown. IHX pod head 502 may include IHX head riser 504 and IHX head collar 506. IHX head collar 506 maybe used to hermetically attach and establish fluid communication between IHX pod 218a to central pod 202 (FIGS. 2 and 3).

[0054] With continued reference to FIG. 5A, guard vessel 220a is configured to form IHX pod inlet port 330 and IHX pod outlet port 332. In one or more instances, the IHX outlet port 332 may be configured to have a larger orifice size to allow greater flow volume compared to IHX pod inlet port 330 to accommodate various flow path configurations (see FIG. 3). The ports for the IHX pod maybe substantially like those of the EMP pod. Guard vessel 220a may further be configured to form IHX pod cover gas port 510. IHX pod cover gas port 510 maybe configured to prevent oxygen from entering the interior 222a of IHX pod 218a.

[0055] Interior 222a of IHX pod 218a may include IHX 304 having IHX outlet 508.IHX 304 and central pod 202 (FIGS. 2 and 3) maybe in fluid communication through IHX outlet 508. Interior 222a may further include IHX pod shielding 520. IHX pod shielding 520 maybe composed of a shielding material (e.g., radiation, such as gamma radiation, shielding material) and configured to prevent radiation from entering the interior 222a of the IHX pod 304.

[0056] FIG. 5B shows a detailed view of a portion of IHX pod 218a. As shown in FIG. 5B, IHX pod 218a includes a guard vessel 220a. FIG. 5B shows IHX pod head 502, IHX head riser 504, and IHX head collar 506. As shown, IHX pod 218a includes IHX pod cover gas port 510 and IHX pod inlet port 330, which may extend through vessel liner 512 located in interior 222a (FIG. 5A) of IHX pod 218a. The vessel liner maybe similar or different than the guard vessel shapes. The guard vessels of the pods may be cylindrical in their entirety. IHX pod 218a maybe initially secured to central pod 202 (not shown) using tabs or flange and bolt or stud assemblies 530 prior to being welded thereto, for example. Although not shown, similar tabs or flange and bolt assemblies maybe associated with the EMP pods 210a, 210b (FIG. 3) to secure the EMP pods 210a, 210b to the central pod 202. In one or more instances, such assemblies 530 maybe removed after welding is completed to form a fully assembled SMV.

[0057] FIGS. 6A and 6B illustrate schematic perspective views of an example external pod head collar 6oo in accordance with one or more embodiments of the present disclosure. Head collar 6oo maybe representative of EMP head collar 406 (FIG. 4A) and / or IHX head collar 506 (FIG. 5A). FIG. 6A illustrates a schematic perspective top view of a head collar 600. Head collar 600 maybe configured to have head collar arch length 602. The head collar arch length 602 maybe used to control the angular placement of EMP pod 210a, 210b and / or IHX pod 218a, 218b. FIG. 6B illustrates a schematic perspective bottom view of a head collar 600 having head collar arch length 602. Head collar 600 further includes a collar weld-buildup for welding attachment to EMP pod 210a, 210b and / or IHX pod 218a, 218b.

[0058] Referring now to FIGS. 7A and 7B, and with continued reference to FIGS. 3 and 6A, where like elements are denoted by like reference numerals, provided are various schematic perspective views of central pod head 700 according to one or more embodiments of the present disclosure. FIG. 7A illustrates a schematic perspective top view of example embodiment SMV system 200 comprising central pod 202; two EMP pods 210a, 210b at opposing locations; and two IHX pods 218a, 218b at opposing locations. Each of EMP pods 210a, 210b and IHX pods 218a, 218b each include head collar 600 (labeled with reference to EMP pod 210b and IHX pod 218b. As shown, central pod 202 includes central pod head 700. Referring now to FIG. 7B, illustrated is a schematic perspective top view of central pod head 700 of central pod 202. As shown, central pod head 700 includes central pod head keyway 702. Keyway 702 maybe configured as a slot or channel machined or otherwise formed within a perimeter of central pod head 700. Keyway 702 maybe configured to be complementary to receive head collar 600 (FIG. 6A and 7A) and to position (orient) each of external EMP pods 210a, 210b and IHX pods 218a, 218b (FIG. 7 A) for hermetic attachment and fluid communication with central pod 202.

[0059] The various components of example embodiment SMV system 200 (FIGS. 2 through 7B) may be fabricated of resilient materials that are compatible with a nuclear reactor environment without substantially changing in physical properties, such as becoming substantially radioactive, melting, embrittlement, and / or retaining / adsorbing radioactive particulates. For example, several known structural materials, including austenitic stainless steels 304 or 316, XM-19, zirconium alloys, nickel alloys, Alloy 600, etc. maybe chosen for any element of components of example embodiment SMV system 200. Joining structures and directly-touching elements may be chosen of different and compatible materials to prevent fouling.METHOD OF SMV ASSEMBLY

[0060] Hermetic attachment, for fluid communication, of the one or more EMP pods and the one or more IHX pods to the central pod, thereby fully assembling an SMV according to the present disclosure, may follow the following described methodology. It is to be appreciated, however, that other methodologies maybe followed provided that operation of the primary coolant loop (and any supplemental coolant loop) are not compromised, without departing from the scope of the present disclosure.

[0061] In one or more instances, and as previously described, the SMV may be shipped as individual pods (i.e., central pod, EMP pod(s), and IHX pod(s)) and fully assembled at a plant location. The assembly method of the present disclosure may include building a temporary or permanent building in which to fully assemble the SMV. The assembly building maybe a bespoke structure having a size and shape sufficient to allow assembly operations, including the size (e.g., length or height, width) of the SMV itself and necessary assembly equipment, such as a gantry, one or more cranes, and the like. Moreover, the assembly building maybe built directly over a silo or containment structure for housing the SMV below ground surface.

[0062] Assembly methods may include first excavating a pit below ground surface and fabricating a silo or containment structure for receiving the SMV therein. In one or more instances, the containment structure is shaped to mimic the shape of the exterior perimeter of the fully assembled SMV (see FIG. 2). The containment structure maybe thus configured to receive the SMV, thereby forming an air space between the exterior perimeter of the fully assembled SMV and the containment structure, which may form an RVACS air space. The containment structure may be composed of cement, concrete, or other suitable material for supporting the SMV and other associated structures, components, buildings, and the like, related to the operation of the SMV.

[0063] Prior to, during, or after excavation and fabrication of the containment structure, various assembly equipment maybe positioned over the containment structure for assembly of the SMV. Such assembly equipment may include a gantry, bridge / walk platform, and the like. Other assembly equipment may include cranes, and the like. Further, prior to, during, or after excavation and fabrication of the containment structure, shipment of the individual SMV pods (central pod, EMP pod(s), and IHX pod(s)) may be received at the plant location.

[0064] Fully assembling the SMV may include lifting the central pod above the containment structure using a gantry. Unwanted movement of the central pod may becontrolled using a fabrication skirt. Thereafter, discharge pipe outlet assembly (see discharge pipe outlet assembly 340 of FIGS. 3, 4A, and 4B) maybe installed into the interior of the central pod.

[0065] The EMP discharge pipe assemblies may next be installed by welding, which may include welding of a pipe support standoff, bracket, or other support structure for ensuring the integrity and positioning of the EMP discharge pipe outlet assemblies (and the associated discharge pipes). Thereafter, opposing external EMP pods are lifted at using pod placement machines (one for each opposing pod) that grip the riser of the EMP pod heads (see FIG. 4A). In one or more instances, the pod placement machines may include a crane and a specially, specifically designed gripping mechanism for the particular configuration of the SMV external pods. The pod placement machines simultaneously position the EMP pod head collars into appropriate opposing central pod head keyways (see FIG. 7B). Simultaneous positioning is critical to ensure proper load balancing (or load distribution) across the SMV and prevent strain upon the gantry supporting (lifting) the SMV pods as the SMV is fully assembled. Upon positioning, the EMP pods are welded and thus hermetically attached to the central pod. In one or more instances, the EMP pods may be bolted or otherwise mechanically affixed to the central pod (see e.g., FIG. 5B) prior to welding.

[0066] Next, opposing external IHX pods are lifted at using the pod placement machines (one for each opposing pod) that grip the riser of the IHX pod heads (see FIG. 5A). The pod placement machines simultaneously position the IHX pod head collars into appropriate opposing central pod head keyways (see FIG. 7B). Simultaneous positioning is critical to ensure proper load balancing (or load distribution) across the SMV and prevent strain upon the gantry supporting (lifting) the SMV pods as the SMV is fully assembled. Upon positioning, the IHX pods are welded and thus hermetically attached to the central pod. In one or more instances, the EMP pods maybe bolted or otherwise mechanically affixed to the central pod (see e.g., FIG. 5B) prior to welding.

[0067] While the present disclosure describes positioning and welding of opposing EMP pods prior to positioning and welding of opposing IHX pods, it is to be appreciated that the methods of the present disclosure may be performed in reverse order. That is, positioning and welding of opposing IHX pods may be completed prior to positioning and welding of opposing EMP pods, without departing from the scope of the present disclosure.

[0068] In one or more instances, the gantry may rotate such that after positioning and welding of the first opposing pair of external pods, the gantry rotates the central pod 90° for positioning and welding of the second opposing pair of external pods.

[0069] Upon fully assembling the SMV, the assembly equipment may be removed from association with the fully assembled SMV and the fully assembled SMV may be lowed into the interior of the containment structure below ground level to its final, installed position.

[0070] Once installed, fully assembled SMV (see FIG. 3) may be activated by allowing liquid metal coolant to flow at least according to the primary coolant loop described herein (see FIG. 3). While one or more example SMV embodiments may be fully assembled and installed, other systems may be in fluid communication or otherwise associated with the SMV, such as an RVACS, a steam generator, a steam generator auxiliary cooling system, a heat transfer system, seismic isolation bearings, and the like, and any combination thereof.

[0071] Example embodiment systems and methods thus being described, it will be appreciated by one skilled in the art that example embodiments may be varied and substituted through routine experimentation while still falling within the scope of the following claims. Such variations are not to be regarded as departure from the scope of these claims.

Claims

What is claimed is:

1. A Shipping Modular Vessel (SMV) system comprising: a central pod housing an inner reactor vessel positioned within an outer central pod guard vessel, the inner reactor vessel being configured to be loaded with nuclear fuel; a first external electromagnetic pump pod (EMP pod) in fluid communication with the central pod, the EMP pod housing an electromagnetic pump and located exterior to the central pod guard vessel; and a first external intermediate heat exchanger pod (IHX pod) in fluid communication with the central pod, the IHX pod housing at least one heat exchanger and located exterior to the central pod guard vessel, wherein the central pod, the first EMP pod, and the first IHX pod form a primary flow path, and wherein the pump is configured to circulate a liquid metal coolant through the primary flow path.

2. The SMV system of claim 1, wherein the liquid metal coolant is liquid sodium.

3. The system of claim 1, wherein the external EMP pod and the external IHX pod are in fluid communication with the central pod at lateral opposing locations.

4. The system of claim 1, further comprising: a second external EMP pod in fluid communication with the central pod at a lateral opposing location to the first EMP pod and located external to the central pod guard vessel; and a second external IHX pod in fluid communication with the central pod at a lateral opposing location to the first IHX pod and located external to the central pod guard vessel.

5. The SMV system of claim 1, wherein the external EMP pod includes a lower cold port inlet, and wherein the primary coolant loop includes the external EMP pod receiving the liquid metal coolant through the lower cold port inlet from the central pod.

6. The SMV system of claim 1, wherein the external EMP pod includes a discharge pipe outlet assembly and the primary coolant loop includes the central pod receiving the liquid metal coolant through the discharge pipe assembly outlet from the external EMP pod.

7. The SMV system of claim 1, wherein the external IHX pod includes an upper IHX pod inlet port and the primary coolant loop includes the external IHX pod receiving the liquid metal coolant through the upper IHX pod inlet port from the central pod.

8. The SMV system of claim 1, wherein the external IHX pod includes a lower IHX pod outlet port and the primary coolant loop includes the central pod receiving the liquid metal coolant through the lower IHX pod outlet port from the external IHX pod.

9. The SMV system of claim 1, wherein the external EMP pod includes an EMP head and the EMP head includes an EMP head collar, and the central pod includes a central pod head and a first keyway that is complementary to the EMP head collar; and wherein the external IHX pod includes an IHX head and the IHX head includes an IHX head collar, and the central pod includes a central pod head and a second keyway that is complementary to the IHX head collar.

10. The SMV system of claim 1, wherein the EMP pod further includes a direct auxiliary cooling system.

11. A method of delivering and / or assembling an SMV system, the method comprising: receiving, at a site for a commercial nuclear power plant, at least one of a central pod configured to house a nuclear core, a first external electromagnetic pump pod (EMP pod) configured to be attached in fluid communication with the central pod and house an electromagnetic pump, and a first external intermediate heat exchanger pod (IHX pod) configured to be attached in fluid communication with the central pod and house an intermediate heat exchanger, wherein none of the central pod, EMP pod, and IHX pod are attached to one another to form a closed, continuous flow path through one another in the receiving; andattaching at least one of the EMP pod and the IHX pod to the central pod at the site so as to form a primary flow path through the central pod and the at least one of the EMP pod and the IHX pod.

12. The method of claim n, wherein the EMP pod includes a lower cold port inlet, and wherein the primary coolant loop includes the external EMP pod configured to receive coolant through the lower cold port inlet from the central pod.

13. The method of claim 11, wherein the external EMP pod includes a discharge pipe outlet assembly and the primary coolant loop includes the central pod configured to receive coolant through the discharge pipe assembly outlet from the external EMP pod.

14. The method of claim 11, wherein the external IHX pod includes an upper IHX pod inlet port and the primary coolant loop includes the external IHX pod configured to receive coolant through the upper IHX pod inlet port from the central pod.

15. The method of claim 11, wherein the external IHX pod includes a lower IHX pod outlet port and the primary coolant loop includes the central pod configured to receive coolant through the lower IHX pod outlet port from the external IHX pod.

16. The method of claim 11, wherein the external EMP pod includes an EMP head and the EMP head includes an EMP head collar, and the central pod includes a central pod head and a first keyway that is complementary to the EMP head collar; and wherein the external IHX pod includes an IHX head and the IHX head includes an IHX head collar, and the central pod includes a central pod head and a second keyway that is complementary to the IHX head collar.

17. The method of claim 11, further comprising: installing an electromagnetic pump in the EMP pod; and installing an intermediate heat exchanger in the IHX pod.

18. The method of claim 11, wherein the attaching includes hermetically sealing the at least one of the EMP pod and the IHX pod to the central pod so that the primary flow path is materially continuous about its entire perimeter.

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