Application of Probabilistic Safety Assessment to Rokkasho Reprocessing Plant, (I) The Occurrence Frequency of Loss of Hydrogen Scavenging Function in Plutonium Solution Vessel

Accession number;07A0057433
Title;Application of Probabilistic Safety Assessment to Rokkasho Reprocessing Plant, (I) The Occurrence Frequency of Loss of Hydrogen Scavenging Function in Plutonium Solution Vessel
Author; TAMAUCHI YOSHIKAZU (Nihon Gennen) SHOJI TATSURO (Nihon Gennen) TAKEBE KAZUMI (Nihon Gennen) SEKINE KEIJI (Nihon Gennen) MATSUOKA SHINGO (Nihon Gennen) TANAKA FUTOSHI (Mitsubishi Heavy Ind., Ltd., JPN) KUROIWA KATSUYA (Mitsubishi Heavy Ind., Ltd., JPN) HAYASHI KAZUYA (Mitsubishi Heavy Ind., Ltd., JPN)
Journal Title;Transactions of the Atomic Energy Society of Japan
Journal Code:L4596A
ISSN:1347-2879
VOL.5;NO.4;PAGE.334-346(2006)
Figure&Table&Reference;FIG.6, TBL.2, REF.44
Pub. Country;Japan
Language;Japanese
Abstract;In the application of the probabilistic safety assessment (PSA) to a reprocessing plant, target accidents for the assessment should be identified first. The HAZOP method developed for a chemical plant was used to identify abnormal candidate events systematically and comprehensively. Among the many abnormal events thus identified, several typical accidents with high latent consequences were selected for the target accidents of PSA. Among them the PSA for complete loss of scavenging air to prevent explosion of radiolyzed hydrogen in the reservoir of concentrated PuNO3 solution is taken up. Its occurrence frequency, uncertainty of the frequency and also relative risk-importance of each apparatus and operator's action composing its prevention were evaluated using the method originally developed for the PSA of a nuclear power plant. The frequency was calculated as 8*10'-6'/yr. The results showed that the design of the scavenging system of the Rokkasho plant is adequate to prevent the accumulation of hydrogen. In addition, it was shown that even the present results with somewhat large uncertainties could be applied for practical use of risk-informed management of the reprocessing plant due to its low latent consequence compared to a nuclear power plant. (author abst.)