In-service inspection of the Very High Temperature Gas-Cooled Reactor

For the guidelines of inservice inspection (ISI) and the first conceptual design of the Very High Temperature Gas-Cooled Reactor, ISI feasibility is described: accessibility to the location of inspection, practicability of examination methods, manpower for ISI, and ISI occupational radiation exposure. Following are the results. About 2,000 man-days are required during each inspection interval (3, 7, 10 years respectively), with about 500 man-rem ISI occupational radiation exposure; this exposure may be lowered by advanced designs of components. There are some problems in the surface examination of pressure retaining welds of inner-bodies in an intermediate heat exchanger. From the above, practicable ISI plans and associated structual design requirements are presneted. (author)