Method and apparatus for annealing nuclear reactor pressure vessels
AssigneeElectric Power Research Institute, Inc.
InventorMelvin E. Lapides
Life of this patent
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Abstract
A nuclear reactor annealing apparatus and method for annealing a vessel of the reactor by utilizing a non-aqueous fluid, a means for replacing water in the vessel with the non-aqueous fluid, a means for heating the non-aqueous fluid to a predetermined temperature and for a predetermined length of time. The non-aqueous fluid creates less pressure than water at the same temperature and is in communication with said vessel so that heating the non-aqueous fluid in turn heats the vessel thereby annealing the vessel. A can device is used to anneal only a portion of the vessel walls.
Claims13
A nuclear reactor vessel annealing system comprising:
- a closed fluid system including said reactor vessel;
- a low vapor pressure non-aqueous fluid having a vapor pressure at elevated temperatures substantially less than the vapor pressure of water in said closed fluid system;
- means for heating said non-aqueous fluid to a predetermined temperature of at least 650.degree. F.;
- and
- means for circulating said non-aqueous fluid through said closed fluid system and said vessel so that said non-aqueous fluid is in heat exchange relationship with at least the portion of said vessel to be annealed.
A nuclear reactor vessel annealing system for annealing a vessel of the reactor:
- a fluid system including said reactor vessel;
- a heat transfer fluid in said fluid system;
- a means for heating said heat transfer fluid to a predetermined temperature and for a predetermined length of time;
- and
- a means for confining said heat transfer fluid so that said heat transfer fluid in said confining means is in heat exchange relationship with a portion of said vessel in said closed fluid system;
- whereby said heated heat transfer fluid heats said portion of said vessel to anneal said portion of said vessel.
The method of annealing the vessel of a nuclear reactor, comprising the steps of:
- circulating a low vapor pressure non-aqueous heat transfer fluid through said vessel whereby said heat transfer fluid is in heat exchange relationship with at least a portion of said vessel, said non-aqueous heat transfer fluid having a vapor pressure substantially less than vapor pressure of water at elevated temperatures;
- heating said heat transfer fluid to a predetermined temperature of at least 650.degree. F.;
- and
- maintaining said heated heat transfer fluid in heat exchange relationship with said vessel for a predetermined length of time;
- whereby said heat transfer fluid heats at least said portion of said vessel to annealing temperature.
Dependencies are inferred from the claim text.