Abstract: A shutdown cooling system for a nuclear reactor operates during lapse of normal power and emergency power and has an independent power source fo removing residual heat while cooling the seals of the main reactor coolant pump. A high pressure pump delivers cooling water to the reactor cooling pump seals, a low pressure pump circulates core coolant, and a cooling mechanism discharges the decay heat. Electrical power for the pumps and associated valves and controls is provided by a dedicated power source apart from the regular residual heat removal apparatus of the reactor, and apart from the emergency generators provided for regular power failure backup.

Abstract: A pipe end sealing element for use in hydrotesting of plain end pipes, such as instrument tubes of a nuclear reactor, and a method of hydrotesting of such plain end pipes. The pipe sealing element comprises a hollow tubular member with a bevelled flange at one end and a threaded portion at the other end, a hollow conical bushing of decreasable interior diameter having a bevelled surface complementary to the bevelled surface of the tubular member, a sealing plug and threaded bolt engageable with the threaded portion of the hollow tubular member. The hollow tubular member is placed about the open end of the pipe, with the threaded portion thereof adjacent and beyond the pipe end, and inserting the conical bushing into the hollow tubular member about the pipe wall. The sealing plug is placed on the pipe end and the threaded bolt engaged with the threads of the hollow tubular member.