Annual report on operation, utilization and technical development of hot laboratories (From April 1, 2004 to March 31, 2005)

This is an annual report in a fiscal year of 2004 that describes activities of the Reactor Fuel Examination facility (RFEF), the Waste Safety Testing Facility (WASTEF), and the Research Hot Laboratory (RHL) in the Department of Hot laboratories. In RFEF, BWR fuel rods were withdrawn from a fuel assembly irradiated for 5 cycles in the Fukusima-2 Nuclear Power Station Unit-1 and PIEs including nondestructive examination of those rods were carried out. Re-assembly of the FUGEN high burn-up mixed oxide fuel and destructive examinations of 55GWd/t fuel rods were carried out. In addition, re-assembly and PIEs for fuel assemblies irradiated in the nuclear ship Mutsu'' were carried out. In WASTEF, Slow Strain Rate Tests (SSRT) for detecting the susceptibility to IASCC of BWR core structural materials in high-temperature water, the corrosion test of reprocessing plant materials, tests for evaluating barrier performance in terms of waste disposal were performed. Pipe specimens cut out from the secondary system in the Mihama Nuclear Power Station Unit-3 were inspected for analyzing the failure mechanism. In addition, auger electron spectroscopy was newly installed to inspect the irradiation embrittlement of structural materials of nuclear power plants. In RHL, 15 lead cells are dismantled under the decommissioning plan at JAERI Tokai. And an arrangement of the RHL facility was started to use the storage of unirradiated nuclear materials. (author)