燃料装荷バスケット及びプラグ検知用圧力検知器の不具合に関する処置

Measures for the failure of pressure detectors for dissolver baskets and plugs

大谷 吉邦; 巖渕 弘樹; 伊藤 信一; 田中 真; 所 武司

not registered; not registered; not registered; not registered; not registered

平成9年に施設・設備等に係わる問題点を自ら洗い出す方針で全社的な安全総点検が実施され、このなかで燃料装荷バスケット及びプラグ検知用圧力検知器の不具合についてを摘出した。この不具合については、原子炉等規制法に基づく許認可手続きを経て工事を実施し平成11年9月に処置を終了している。一方で、本件は安全総点検で摘出された事項のなかでも特に報道機関・市民団体等の関心が高く、適宜種々の問い合わせに対応してきているところである。本報告書は、上記の経緯を踏まえ事実を整理し正しい情報の継承を図ることを目的として、不具合発生から処置に至る対応全般についてを総括的に取りまとめたものである。

Safety review for the whole facilities and equipments of the Japan Nuclear Cycle Development Institute(JNC) was carried out in order to dig up their problems voluntarily in 1997, and the failure of pressure detectors making sure that dissolver baskets and plugs were in each right position was taken out from these investigations. An improving treatment for this failure finished in September, 1999, after legal formalities with the Law for the Regulations for Nuclear Source Material, Nuclear Fuel Material and Reactors had been completed. While many problems were taken out from the safety review, on the other hand mass media and citizen groups particularly took an interest in this detector's trouble which concerned criticality safety of the dissolver unit. Consequently we have been replaying to various questions from them. For the purpose of being sure to keep accurate facts of this trouble and handing down these information, general countermeasure covered from occurrence of this trouble to completion of improving work was described.