FMF増設施設集合体試験装置の開発; 「常陽」集合体の寸法測定断面形状測定試験

Development of multipurpose test Apparatus for core assemblies in FMF-extention; Examination of size and cross section from measurement for core assemblies irradiated in "JOYO"

佐々木 新治  ; 阿部 和幸; 永峯 剛; 松元 愼一郎

not registered; Abe, Kazuyuki; not registered; Matsumoto, Shinichiro

大洗工学センターの照射燃料集合体試験施設には、既設施設に加え、高速増殖炉「もんじゆ」などの大型集合体を取り扱うための増設施設が付設されている。そこに設置するために集合体縦型試験装置を開発し、これまでに高速実験炉「常陽」の集合体6体の寸法測定等を試験的に実施してきた。本装置は多機能を有しており、外観検査と各種の寸法測定、さらには集合体の解体が可能である。寸法測定としては、集合体の全長,対面間寸法,頂角間寸法,曲がり,ねじれを同時に自動的に測定する機能を有する。さらに、新たに開発した専用の治具を用いることにより、集合体の断面形状の測定も行うことができる。集合体の全長,対面間寸法および頂角間寸法の結果についてはFMF既設施設に設置されている校正済みの集合体寸法測定装置の値と比較し、測定誤差内にあることを確認した。曲がりに関しては、最大で1mmを越える差が見られた。これは、両装置の測定方法の違いを考慮すれば、必ずしも有意な差ではないと考えられる。新たに導入した断面形状測定については、寸法測定結果から算出された値と比較して、測定誤差範囲内で一致した。このデータはこれまでの装置では直接取得できないものであった。

In the place adjacent to the Fuel Monitoring Faciliy (FMF) in the O-arai Engineering Center, FMF-Extension was constructed to examine large subassemblies irradiated in the prototype fast breeder reactor "MONJU" and so on. Until now, in order to confirm the performances of subassembly vertical examination machine, which is one of main apparatus installed in FMF-Extension, it has been experimentally conducted, to measure six subassemblies irradiated in the experimental fast reactor "JOYO". This machine has multi-functions such as appearance inspection, various size measurements and dismantling a subassembly. As to the size measurements, it is possible to measure subassembly length, hexagonal wrapper tube face-to-face distance, corner-to-comer distance, bowing and twisting automatically. Furthermore, this machine has a function of grasping the cross section form of hexagonal wrapper tube, using a new special tool. The results measured by this machine were compared with the data of the same subassemblies with the exiting machine in FMF, which was calibrated already. For the date of subassembly length, hexagonal wrapper tube face-to-face distance and corner-to-corner distance, the difference of both machines was within a measurement error. In some results of bowing, the difference was over 1mm. It was thought that the difference was not a considerable error when taking into account the characteristics of these machines that the error was easy to propagate. The results of cross section from of hexagonal wrapper tube newly introduced in this machine were in a good agreement within a measurement error, compared with the data calculated on the basis of size measurement results. The existing machine in FMF could not treat this cross section form measurement.