IP Library Granted Patent US 12,437,888
Granted Patent B2
US 12,437,888 · App. 17/640,033 · Granted Oct 7, 2025

Nuclear reactor core architecture with moderator elements inside insulator elements

Inventors: Paolo Francesco Venneri (Seattle, WA); Michael John Eades (Seattle, WA); Kelsey Souza (Seattle, WA); Wesley Deason (Seattle, WA)
Assignee: LOKI MMR INC.
G21C11/022G21C5/12G21C7/12G21D5/02B64D27/22G21C3/626G21C9/02G21C11/06G21C13/02G21C15/08
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,437,888
App. No.
17/640,033
Granted
Oct 7, 2025
Kind
B2
Abstract

An enhanced architecture for a nuclear reactor core includes: (1) nuclear fuel tiles (S-Block); and (2) a thermal insulator and tube liners with a solid-phase moderator (U-Mod) to improve safety, reliability, heat transfer, efficiency, and compactness. In S-Block, nuclear fuel tiles include a fuel shape designed with an interlocking geometry pattern to optimize heat transfer between nuclear fuel tiles and into a fuel coolant and bring the fuel coolant in direct contact with the nuclear fuel tiles. Nuclear fuel tiles can be shaped with discontinuous nuclear fuel lateral facets and have fuel coolant passages formed therein to provide direct contact between the fuel coolant and the nuclear fuel tiles. In U-Mod, tube liners with hydrogen diffusivity retain hydrogen in the solid-phase moderator even at elevated temperatures and the thermal insulator insulates the solid-phase moderator from the nuclear fuel tiles.

Claims (100)

1. A nuclear reactor system comprising:

a nuclear reactor core including:

an insulator element array of insulator elements;

a plurality of tube liners formed of a hydrogen barrier material;

a neutron moderator element array of moderator elements, wherein a respective moderator element is formed of a solid-phase moderator disposed inside a respective insulator element; and

a nuclear fuel tile array of nuclear fuel tiles, wherein a respective nuclear fuel tile includes a plurality of nuclear fuel lateral facets that border the respective insulator element or another respective nuclear fuel tile;

wherein:

the respective moderator element is insulated from the nuclear fuel tile array of nuclear fuel tiles by the respective insulator element,

the respective moderator element is disposed inside a respective tube liner, and

the respective tube liner is formed as a cladding that sheaths the respective moderator element.

2. The nuclear reactor system of claim 1 , further comprising a plurality of moderator coolant passages, wherein:

the respective tube liner is surrounded by a respective moderator coolant passage; and

the respective moderator coolant passage is surrounded by the respective insulator element.

3. The nuclear reactor system of claim 2 , wherein:

the respective tube liner is between the respective moderator element and the respective moderator coolant passage; and

the respective moderator coolant passage is between the respective tube liner and the respective insulator element.

4. The nuclear reactor system of claim 2 , wherein:

the respective insulator element is between the respective moderator coolant passage and the respective nuclear fuel tile.

5. The nuclear reactor system of claim 1 , wherein:

the cladding includes a hermetically sealed container; and

the solid-phase moderator material forming the respective moderator element is disposed inside the hermetically sealed container.

6. The nuclear reactor system of claim 1 , wherein:

the respective tube liner is formed as a coating on the respective moderator element; and

the solid-phase moderator material forming the respective moderator element is disposed inside the coating.

7. The nuclear reactor system of claim 1 , wherein:

the hydrogen barrier material includes Al y O x , SiC, ZrC, MgO, Mo, W, Cu, Ni, Cr, or a combination thereof.

8. The nuclear reactor system of claim 1 , wherein:

each of the insulator elements is formed of a thermal insulator; and

the thermal insulator includes SiC, stabilized zirconium oxide, aluminum oxide, ZrC, carbon, or a combination thereof.

9. The nuclear reactor system of claim 1 , wherein:

the solid-phase moderator includes MgH x , YH x , ZrH x , CaH x , ZrO x , CaO x , BeO x , BeC x , Be, enriched boron carbide, 11 B 4 C, CeH x , LiH x , or a combination thereof.

10. The nuclear reactor system of claim 1 , wherein:

the respective insulator element is shaped as a prism or a cylinder that includes a moderator opening formed longitudinally therein; and

the respective moderator element is disposed inside the moderator opening.

11. The nuclear reactor system of claim 1 , wherein:

the respective insulator element includes a plurality of insulator element lateral facets that in aggregate shape the respective insulator element as a prism.

12. The nuclear reactor system of claim 11 , wherein:

the respective insulator element is shaped as the prism;

the prism includes a plurality of insulator element border walls; and

each of the insulator element border walls includes a subset of the insulator element lateral facets.

13. The nuclear reactor system of claim 11 , wherein:

the insulator element lateral facets are planar, aspherical, spherical, or freeform surfaces.

14. The nuclear reactor system of claim 12 , wherein:

the insulator element border walls include an alternating pattern of a planar surface with an aspherical or spherical surface.

15. The nuclear reactor system of claim 11 , wherein:

the prism is a triangular prism; and

the respective insulator element includes three insulator element border walls.

16. The nuclear reactor system of claim 1 , wherein:

each of the nuclear fuel tiles is formed of a fuel compact comprised of coated fuel particles embedded inside a matrix; and

the matrix includes silicon carbide, zirconium carbide, titanium carbide, niobium carbide, tungsten, molybdenum, or a combination thereof.

17. The nuclear reactor system of claim 16 , wherein:

the coated fuel particles includes tristructural-isotropic (TRISO) fuel particles or bistructural-isotropic (BISO) fuel particles.

18. The nuclear reactor system of claim 1 , wherein:

the plurality of nuclear fuel lateral facets are discontinuous to form an outer periphery of the respective nuclear fuel tile.

19. The nuclear reactor system of claim 18 , wherein:

the outer periphery includes a plurality of planar, aspherical, spherical, or freeform surfaces.

20. The nuclear reactor system of claim 1 , wherein:

the nuclear fuel lateral facets alternate between bordering the respective insulator element and the other respective nuclear fuel tile.

21. The nuclear reactor system of claim 1 , wherein:

the nuclear fuel lateral facets include a plurality of tile interface walls and a plurality of insulator element interface walls; and

a respective tile interface wall alternates with a respective insulator element interface wall to form an alternating pattern of the outer periphery.

22. The nuclear reactor system of claim 21 , wherein:

the respective tile interface wall includes a planar surface.

23. The nuclear reactor system of claim 21 , wherein:

the respective tile interface wall includes two nuclear fuel lateral facets with a nuclear fuel lateral facet extending between;

the two nuclear fuel lateral facets include a planar surface; and

the nuclear fuel lateral facet extending between includes an aspherical or spherical surface.

24. The nuclear reactor system of claim 21 , wherein:

the respective tile interface wall borders the other respective nuclear fuel tile; and

the respective insulator element interface wall borders the respective insulator element.

25. The nuclear reactor system of claim 21 , wherein:

the respective insulator element interface wall includes an aspherical or spherical surface.

26. The nuclear reactor system of claim 21 , wherein:

the respective insulator element is shaped as a tube or a pipe; and

the respective insulator element lines the respective insulator element interface wall of two or more nuclear fuel tiles.

27. The nuclear reactor system of claim 1 , wherein:

the respective insulator element with the respective moderator element disposed inside includes a respective moderator coolant passage formed therein.

28. The nuclear reactor system of claim 27 , wherein:

the respective moderator coolant passage is located between the respective moderator element and the respective insulator element.

29. The nuclear reactor system of claim 27 , wherein:

the respective moderator coolant passage is a flattened ring shaped opening.

30. The nuclear reactor system of claim 27 , wherein:

the respective moderator coolant passage flows a coolant through to both: (i) heat the coolant, and (ii) cool the respective moderator element;

the respective nuclear fuel tile includes one or more fuel coolant passages formed therein for subsequent heating of the coolant by the respective nuclear fuel tile after the coolant flows through the moderator coolant passage; and

the coolant is a gas or a liquid.

31. The nuclear reactor system of claim 27 , wherein:

the respective moderator coolant passage flows a moderator coolant through to both: (i) heat the moderator coolant, and (ii) cool the respective moderator element; and

the respective nuclear fuel tile includes one or more nuclear fuel coolant passages formed therein that flow a nuclear fuel coolant to heat the nuclear fuel coolant via direct contact with the respective nuclear fuel tile.

32. The nuclear reactor system of claim 31 , wherein:

the moderator coolant that flows through the respective moderator coolant passage is in a moderator coolant loop dedicated to the neutron moderator element array of moderator elements and that is thermally isolated and separated from a fuel coolant loop that includes the nuclear fuel coolant passages.

33. The nuclear reactor system of claim 32 , wherein:

the moderator coolant loop thermally isolates the moderator coolant from the nuclear fuel coolant to actively remove heat from the moderator elements to maintain the moderator elements at a lower temperature compared to the nuclear fuel tile array of nuclear fuel tiles during operation of the nuclear reactor core.

34. The nuclear reactor system of claim 32 , wherein:

the moderator coolant is different than the nuclear fuel coolant.

35. The nuclear reactor system of claim 1 , further comprising a turbine and a compressor.

36. The nuclear reactor system of claim 1 , further comprising a pump, a compressor, a blower, or a combination thereof.

37. The nuclear reactor system of claim 1 , wherein:

the respective moderator element is disposed inside the respective tube liner for hydrogen retention.

38. The nuclear reactor system of claim 1 , wherein:

the respective moderator element is disposed inside the respective tube liner for coolant or propellant retention.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 6, 2025
From: ULTRA SAFE NUCLEAR CORPORATION
To: LOKI MMR INC.
Reel/Frame 070131/0480 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 4, 2022
From: VENNERI, PAOLO FRANCESCO; EADES, MICHAEL JOHN; SOUZA, KELSEY; DEASON, WESLEY
To: ULTRA SAFE NUCLEAR CORPORATION
Reel/Frame 059173/0189 →
Continuity (2)
Provisional Application 62910561 · Oct 4, 2019
Related Publication 20220301732A1 · Sep 22, 2022
References Cited (25)
US 3129140A · Stohr et al. · 1964 [cited by applicant]
US 4569820A · Fortescue · 1986 [cited by applicant]
US 4626405A · Field et al. · 1986 [cited by applicant]
US 5410578A · Walton · 1995 [cited by applicant]
US 9299464B2 · Venneri et al. · 2016 [cited by applicant]
US 9620248B2 · Venneri · 2017 [cited by applicant]
US 10032528B2 · Venneri · 2018 [cited by applicant]
US 10109378B2 · Snead · 2018 [cited by applicant]
US 10475543B2 · Venneri · 2019 [cited by applicant]
US 10573416B2 · Venneri · 2020 [cited by applicant]
US 10643754B2 · Venneri · 2020 [cited by applicant]
US 12249435B2 · Barringer · 2025 [cited by examiner]
US 20170249999A1 · DeWitte et al. · 2017 [cited by applicant]
US 20170263345A1 · Venneri et al. · 2017 [cited by applicant]
US 20200027587A1 · Venneri · 2020 [cited by applicant]
GB 963565A · 1964 [cited by applicant]
The extended European Search Report issued Feb. 16, 2024, by the European Patent Office in corresponding European Patent Application No. 20871765.2-1212. (8 pages). [cited by applicant]
Office Action (Notice of Reasons for Rejection) issued May 14, 2024, by the Japan Patent Office in corresponding Japanese Patent Application No. 2022-516343 and an English translation of the Office Action. (10 pages). [cited by applicant]
International Preliminary Report on Patentability for International Application No. PCT/US2020/054190, dated Apr. 5, 2022, 5 pages. [cited by applicant]
International Search Report and Written Opinion for International Application No. PCT/US2020/054190, dated Feb. 17, 2021, 6 pages. [cited by applicant]
McClure, P., “Design and Testing of Small Nuclear Reactors for Defense and Space Applications,” Invited Talk to ANS Trinity Section, Los Alamos National Laboratory, Santa Fe, NM, Sep. 20, 2013, 52 pages. [cited by applicant]
National Aeronautics and Space Administration (NASA), “Prometheus Project Final Report,” 982-R120461, Oct. 1, 2005, 227 pages. [cited by applicant]
Poston et al., “Reference Reactor Module Design for NASA's Lunar Fission Surface Power System,” Proceedings of Nuclear and Emerging Technologies for Space 2009, Atlanta, GA, Jun. 14-19, 2009, 18 pages. [cited by applicant]
Office Action, Communication pursuant to Article 94(3) EPC, issued Mar. 17, 2025, by the European Patent Office in corresponding European Patent Application No. 20 871 765.2-1211. (5 pages). [cited by applicant]
Office Action, Notice of Preliminary Rejection, issued Jun. 19, 2025, by the Korean Intellectual Property Office in corresponding Korean Patent Application No. 10-2022-7014930. (12 pages). [cited by applicant]