プルトニウム消費型高速炉の特性解析(II)

An evaluation of core characteristics of the Pu burning by LMFRs (II)

矢野 眞理*; 大久保 良幸*; 小山 和也*; 田中 洋司*

not registered; not registered; not registered; not registered

これまでに炉心の主要性能を損ねることなくPu消滅特性を向上きせる為の高速炉の各種炉心概念(中性子漏洩増大型高富化度炉心,吸収材添加型高富化度炉心等)の検村を行い、反応度特性を含む主要炉心特性を把握した。昨年度は80万kWe級炉心を対象に炉心高さ60cm、炉心直径5.3m、運転サイクル日数123日の基準炉心を選定し、炉心高さ、燃料体積比等の炉心パラメータが炉心特性に及ぽす影響を広範囲に解析秤価した。本年度は炉出カを60万kWeとし、以下の仕様条件の下で解析を実施し、Pu消費型高速炉の概念を更に明確にした。主要仕様は以下の通りである。炉心高さ :60cm炉心直径 :4m以内違転期間 :半年程度検討対象とした炉心概念は、(1)高富化度炉心1(最大45w/O Pu富化度)(2)高富化度炉心2(乎均30w/O Pu富化度)(3)B4C添加型炉心である。・また高富化度炉心1をペースに,1・出カ密度,2・MA添加,4・Pu組成比変更の影響を調べた.更に上紀(1).(2)の炉心を対象に炉心動特性解析を行い、ULOF、UTOP時の受動的炉停止能力を検討すると共に従来炉(60万kWe級MOX燃料炉心)との比較もおこなった。

Until now, the investigation was conducted for the concept of various kinds of core (high-Pu enrichment core with increased neutron leakage, absorber addition type high-Pu enrichment core, etc.) in LMFRs to improve the Pu transmutation characteristics without damaging main characteristics of the core, and the main core characteristics including reactivity characteristics were obtained. In preceding year, the reference core with core height of 60cm, core equivalent diameter of 5.3 m and refueling interval (123 days) was selected on 800MWe core, and the effect of the core parameters such as core height, fuel volume fraction, etc. upon the core characteristic was analyzed and evaluated. In this year, the analysis was performed under the below-mentioned specification conditions, and the concept of the Pu burner fast reactor was further clarified. The main specifications are as follows: (Core hight: 60cm) (Equivalent core diameter: 4 m or shorter) (Refueling interval: around half year) The core concept of investigation object is: (1)High-Pu enrichment core 1 (Pu enrichment:45w/o at maximum) (2)High-Pu enrichment core 2 (Pu enrichment:30w/o as average) (3)BC addition type core Also, based on the high-Pu enrichment core 1, the effect was surveyed for (1)power density, (2)MA addition and (3)Pu composition ratio change, Further, the transient characteristics of the cores of (1) and (2) were analyzed under the ULOF and UTOP events, and, at the same time, the comparison with the conventional MOX core (600MWe FBR) was also conducted. .....