PRESSURIZED-WATER REACTOR INSPECTION PROC EDURES

Inspections of the reactor pressure vessels of pressurized water react ors (PWR) so far used to be carried out with different central mast ma nipulators, For technical reasons, parallel inspections of two manipul ators alongside work on the refueling cavity, so as to reduce the time spent on the critical path in a revision outrage, are not possible. E fforts made to minimize the inspection time required with one manipula tor have been successful, but their effects are limited. Major reducti ons in inspection time can be achieved only if inspections are run wit h two manipulators in parallel. The decentralized manipulator built by GEC Alsthom Energie and so far employed in boiling water reactors in the USA, Spain, Switzerland and Japan allows two systems to be used in parallel, thus reducing the time required inspection of a pressure ve ssel from som six days to three days. These savings of approximately t hree days are made possible without any compromises in terms of positi oning by rail-bound systems. During inspection, the reactor refueling cavity is available for other revision work without any restrictions. The manipulator can be used equally well for inspecting standard PWR, PWR with a thermal shield. for inspecting the land between in-core ins trumentation nozzles, BWR with and without jet pumps (complementary in spection), and for inspecting core support shrouds.