Nuclear reactor locking piston drive system and valve assembly

摘要

A locking piston drive system and valve assembly is provided for shutdown of a nuclear reactor. "Chatter" in a check valve assembly which occurs during charging and/or re-charging of control fluid within a control line is eliminated by providing a valve head and a resisting portion defined on the valve head to resist movement of the valve, head when it is urged from sealing engagement on its seat during the charging or re-charging procedure.