Investigation on spent fuel characteristics of Reduced-Moderation Water Reactor (RMWR)

低減速軽水炉(RMWR)における使用済燃料特性の検討

深谷 裕司   ; 大久保 努; 内川 貞夫

Fukaya, Yuji; Okubo, Tsutomu; Uchikawa, Sadao

低減速軽水炉(RMWR)における使用済燃料特性の検討をSWATコードとORIGENコードを用いて行った。この評価においてはRMWR用のORIGENライブラリが必要であったが、公開されたものが存在しなかったため本研究においてSWATコードを用いて作成した。RMWRの使用済燃料特性を検討するために崩壊熱,放射能,各核種の組成をORIGENを用いて評価した。また、これらについてほかの炉型に対する評価も行った。RMWRの使用済燃料における崩壊熱と放射能はフルMOX軽水炉やFBRのものよりも低く、高燃焼度PWRと同程度のものであることがわかった。加えて、廃棄物処理の観点から、発熱性元素,白金族元素, Mo, LLFPについての検討も行った。

The spent fuel characteristics of the reduced-moderation water reactor (RMWR) have been investigated using the SWAT and ORIGEN codes. In the code calculation, the ORIGEN libraries for RMWR were necessary. Since there were no open libraries for RMWR, they were produced in this study by using the SWAT code. In order to investigate the characteristics of the RMWR spent fuel, the decay heat, the radioactivity and the content of each nuclide were evaluated with ORIGEN using these libraries. In this study, the spent fuel characteristics of other types of reactors were also evaluated with ORIGEN. It has been found that the decay heat and the radioactivity of the RMWR spent fuel are lower than those of full-MOX-LWRs and FBR, and are the same level as those of the high burn-up PWR. In addition, from the waste disposal point of view, the characteristics of the heat generation FP elements, the platinum group metals, Mo and the long-lived FPs (LLFPs) were also investigated.