Patent Number: 063174774
Section: abstract

A seal assembly for sealing a space between an annular flange on a nuclear reactor vessel and a surrounding ledge of a refueling canal to provide a temporary water barrier during refueling operations. The seal assembly includes an annular closure plate having an outer portion secured to the surrounding ledge and an inner portion supporting a first sealing surface. A second sealing surface opposing the first sealing surface is formed on or secured to the annular flange of the reactor vessel. An annular space between the first and second sealing surfaces provides a ventilation path from the reactor cavity during normal plant operation. The annular space is sealed by an inflatable seal during refueling operations to provide a water barrier between the refueling canal and the reactor vessel. The inflatable seal is secured to and supported by an annular support structure that straddles the annular space. The annular support structure provides a structure for handling the inflatable seal during installation and removal. The annular support structure also provides a leak limiting function in the event the inflatable seal is pulled or pushed through the annular space or otherwise fails to seal the annular space. The inflatable seal is secured to the annular support structure in a manner that allows independent movement of the seal to conform to irregularities in the sealing surfaces. The closure plate has a plurality of normally closed access ports that permit access to the external core detectors and the reactor vessel cavity.