Nuclear reactor coolant system inventory control system and method
AssigneeRust Industrial Services Inc.
InventorsCliff Evans, Jagdish H. Shah
Life of this patent
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Abstract
A nozzle dam has a valve controlled passage through the nozzle dam wall for releasing trapped gas from the nozzle in the region below the nozzle dam. The gas is released while the reactor coolant system water general level is above the level of the nozzle dam.
Claims12
In a nozzle dam for hermetically sealing against a wall of a nozzle of the steam generator bowl of a water cooled nuclear reactor primary coolant system against passage of fluids between said nozzle and said bowl, said nozzle dam comprising:
- passage means completely through said nozzle dam for releasing gas from the nozzle in the region below the nozzle dam, through the dam, to said bowl when said nozzle dam is mounted sealingly in said nozzle.
In a water cooled nuclear reactor primary coolant system in which a nozzle dam is in place for hermetically sealing a nozzle of the steam generator bowl, a method for reducing the chance of uncontrolled drop of reactor coolant system inventory level below mid loop level when a hermetic seal between the nozzle and steam generator bowl is broken, said method comprising:
- after the reactor coolant system water general level is raised to a level that is higher than the nozzle dam, and
- before completion of a later step of lowering of the reactor coolant system water general level to bring it to a level that is below the nozzle dam wherein taking of the general level below the nozzle dam is not yet attained,
- the intermediate step of opening a passage exiting the nozzle for release of trapped gas through said passage from the nozzle from the region immediately below the nozzle dam.
In a water cooled nuclear reactor primary coolant system in which a nozzle dam is in place for hermetically sealing a nozzle of the steam generator bowl, a method for reducing the chance of uncontrolled drop of reactor coolant system inventory level below mid loop level when a hermetic seal between the nozzle and steam generator bowl is broken, said method comprising:
- in preparation for removing said nozzle dam from said nozzle,
- before completion of the step of lowering of the reactor coolant system water general level to bring it to a level that is below the nozzle dam, wherein taking of the general level below the nozzle dam is not yet attained,
- the step of opening a passage exiting the nozzle for release of trapped gas from the nozzle in the region immediately below the nozzle dam, and keeping the passage open until the trapped gas is released and water in the nozzle rises to the dam.
Dependencies are inferred from the claim text.