초록 ▼

An irradiated steel pressurized nuclear reactor pressure vessel 10 is provided with a crack initiation retarding and crack extension retarding reactor vessel integrity girdle 20 or 120 made up of shoes or links 22, with mechanical take up joints (26 to 34a or 126 to 134a). Instead of pivoted shoe li

An irradiated steel pressurized nuclear reactor pressure vessel 10 is provided with a crack initiation retarding and crack extension retarding reactor vessel integrity girdle 20 or 120 made up of shoes or links 22, with mechanical take up joints (26 to 34a or 126 to 134a). Instead of pivoted shoe links 22, the girdle 120 may be made using constricting roller chain links 122. In any event, crack initiation and crack extension which may result from pressure loading or vessel material embrittled in the beltline region by neutron bombardment is retarded by maintenance of a prestress under the nozzles during all periods of operation of the reactor.

대표청구항 ▼

A method of providing a preloaded radial compression girdle for an integral steel nuclear pressurized water reactor pressure vessel to retard crack initiation and to retard crack extension in said vessel which comprises the combination of steps of: determining in-situ in an existing operating nuclea

A method of providing a preloaded radial compression girdle for an integral steel nuclear pressurized water reactor pressure vessel to retard crack initiation and to retard crack extension in said vessel which comprises the combination of steps of: determining in-situ in an existing operating nuclear plant on an irradiated vessel the overall radial growth and shrinkage of said vessel during the vessel\s normal heat-up period, during the vessel\s steady state operation period and during a hypothetical pressurized thermal shock event of the vessel which includes during a rapid cooldown and depressurization period of the vessel and during a repressurization period of the vessel; applying and preloading a metal radial compression girdle to maintain a positive prestress radial load on said vessel during each of said periods and during said event in intimate and positive radial contact with the outer vessel surface to maintain radial compression thereon during each of said periods, and during occurrence of any such event, to retard crack initiation and to retard crack extension in said vessel.