Iron-based composition for fuel element

Patent metadata

Field	Value
Publication number	US-10930403-B2
Application number	US-201816222587-A
Country	US
Kind code	B2
Filing date	Dec 17, 2018
Priority date	Dec 28, 2012
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.

First claim

What is claimed is:

1. A steel composition comprising:
Cr at between about 10.0 wt% and about 13.0 wt%;
C at between about 0.17 wt% and about 0.23 wt%;
Mo at between about 0.80 wt% and about 1.2 wt%;
Si less than or equal to about 0.5 wt%;
Mn less than or equal to about 1.0 wt%;
V at between about 0.25 wt% and about 0.35 wt%;
W at between about 0.40 wt% and about 0.60 wt%; and
Fe at least 80 wt%;
wherein the processing of the steel composition includes transforming at least some of the steel composition into an austenite phase by heating the steel composition to a temperature from 1100° C. to 1300° C. for 40-60 hours.

2. The steel composition of claim 1 ,
wherein the steel composition has been processed so that it exhibits a swelling of less than 0.9% by volume at a depth between 500-700 nm below the surface after dual-beam Fe++ and He++ irradiation to doses of 188 displacements per atom (dpa) with 0.2 appm He/dpa, as calculated using the Stopping Range in Matter simulation with the K-P option for damage cascades and a 40 eV displacement energy, created by irradiating the steel composition at 460° C. with a defocused beam of 5 MeV Fe++ ions and a raster-scanned beam of ˜2 MeV He++ ions transmitted through a thin Al foil for scattering and energy reduction to create a uniform He profile at the irradiation depth of a sample of the steel composition.

3. The steel composition of claim 2 , wherein the steel composition exhibits a swelling of less than 0.75% by volume.

4. The steel composition of claim 2 , wherein the steel composition exhibits a swelling of less than 0.5% by volume.

5. The steel composition of claim 2 , wherein the steel composition exhibits a swelling of less than 0.3% by volume.

6. The steel composition of claim 1 , wherein the steel composition is an HT9 steel.

7. A fuel element made of the steel composition of claim 1 .

8. A component of a fuel assembly made of the steel composition of claim 1 .

9. A steel composition comprising:
(Fe) a (Cr) b (Mo, Ni, Mn, W, V) c N d ;
wherein
a, b, c, and d are each a number greater than zero representing a weight percentage;
b is between 11 and 13;
c is between about 0.25 and about 0.9;
d is between about 0.01 and about 0.04; and
balanced by a; and
wherein the processing of the steel composition includes transforming at least some of the steel composition into an austenite phase by heating the steel composition to a temperature from 1100° C. to 1300° C. for 40-60 hours.

10. The steel composition of claim 9 , wherein b is between 11.5 and 12.5.

11. The steel composition of claim 9 ,
wherein the steel composition has been processed so that it exhibits a swelling of less than 0.9% by volume at a depth between 500-700 nm below the surface after dual-beam Fe++ and He++ irradiation to doses of 188 displacements per atom (dpa) with 0.2 appm He/dpa, as calculated using the Stopping Range in Matter simulation with the K-P option for damage cascades and a 40 eV displacement energy, created by irradiating the steel composition at 460° C. with a defocused beam of 5 MeV Fe++ ions and a raster-scanned beam of ˜2 MeV He++ ions transmitted through a thin Al foil for scattering and energy reduction to create a uniform He profile at the irradiation depth of a sample of the steel composition.

12. The steel composition of claim 11 , wherein the steel composition exhibits a swelling of less than 0.75% by volume.

13. The steel composition of claim 11 , wherein the steel composition exhibits a swelling of less than 0.5% by volume.

14. The steel composition of claim 11 , wherein the steel composition exhibits a swelling of less than 0.3% by volume.

15. The steel composition of claim 9 , wherein the steel composition is an HT9 steel.

16. A fuel element made of the steel composition of claim 9 .

17. A component of a fuel assembly made of the steel composition of claim 9 .

18. The steel composition of claim 1 , wherein:
Cr is at between about 10.0 wt% and about 12.5 wt%;
C at between about 0.17 wt% and about 0.22 wt%;
Mo at between about 0.80 wt% and about 1.2 wt%;
Si less than or equal to about 0.5 wt%;
Mn less than or equal to about 1.0 wt%;
V at between about 0.25 wt% and about 0.35 wt%;
W at between about 0.40 wt% and about 0.60 wt%;
P less than or equal to about 0.5 wt%;
S less than or equal to about 0.5 wt%; and
Fe at least 80 wt%.

19. The steel composition of claim 1 , further comprising:
Ni at between about 0.3 wt% and about 0.7 wt%.

20. The steel composition of claim 1 , wherein at least substantially all of the composition is in the martensite phase.

Assignees

• Terrapower Llc

Inventors

• Hackett Micah J
• Klueh Ronald L

Classifications

• G21C3/08

  provided with external means to promote heat-transfer, e.g. fins, baffles · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C21D6/02

  Hardening by precipitation · CPC title

• C21D2211/008

  Martensite · CPC title

• C22C38/18

  containing chromium · CPC title