Patent Number: 
Section: claims

1. A method comprising:adjusting a reactor coolant system to provide heat from a coolant of the reactor coolant system to a component to be annealed to produce a temperature deviation from a nominal operating temperature range;based at least in part on the heat from the coolant, maintaining the temperature deviation from the nominal operating temperature for a period selected to produce a selected annealing effect on the component; andafter the period selected to produce the selected annealing effect, adjusting the reactor coolant system to return to the nominal operating temperature range. 2. The method of claim 1, wherein adjusting a reactor coolant system to produce a temperature deviation from a nominal operating temperature range includes adjusting reactor coolant flow. 3. The method of claim 1, wherein adjusting a reactor coolant system includes reversing direction of reactor coolant flow. 4. The method of claim 1, wherein adjusting a reactor coolant system includes adjusting a rate of heat generation. 5. The method of claim 1, wherein adjusting a reactor coolant system to produce a temperature deviation from a nominal operating temperature range includes adjusting a rate of heat transferred from the reactor coolant. 6. The method of claim 1, wherein adjusting a reactor coolant system to produce a temperature deviation from a nominal operating temperature range includes adjusting a rate of heat transferred to the reactor coolant. 7. The method of claim 1, wherein adjusting a reactor coolant system to produce a temperature deviation from a nominal operating temperature range includes replacing at least a portion of a first reactor coolant having first heat transfer characteristics with second coolant having second heat transfer characteristics. 8. The method of claim 1, wherein adjusting a reactor coolant system to produce a temperature deviation from a nominal operating temperature range includes adjusting a temperature of reactor coolant. 9. The method of claim 1, wherein the selected annealing effect anneals at least one reactor core component chosen from a nuclear fission fuel assembly, a reactor core cooling component, and a reactor core structural member. 10. The method of claim 9, wherein the at least one reactor core component includes at least one nuclear fission fuel assembly component chosen from cladding, a cooling component, a structural member, a thermally conductive member, and nuclear fission fuel material. 11. The method of claim 1, wherein adjusting a reactor coolant system includes providing heat generated by a nuclear fission fuel material. 12. The method of claim 11, wherein providing heat generated by a nuclear fission fuel material includes providing decay heat from a fuel assembly containing the component. 13. The method of claim 11, wherein the nuclear fission fuel material is co-located with at least a portion of the reactor coolant system are co-located within a nuclear reactor vessel. 14. The method of claim 11, wherein providing heat generated by a nuclear fission fuel material includes reducing an amount of heat transferred from a coolant of the reactor coolant system. 15. The method of claim 8, wherein adjusting a temperature of reactor coolant includes heating coolant of the reactor coolant system using an external heat source.