AMIR-8照射キャプセルの設計

The design of irradiation capsules for absorber material irradiation rig-8

永田 貴子  ; 丸山 忠司; 小野瀬 庄二 

Nagata, Takako; Maruyama, Tadashi; Onose, Shoji

高速炉制御棒の長寿命化を達成するため高温シュラウドを有するヘリウムボンドシュラウド型吸収ピン及びナトリウムシュラウド型吸収ピンの開発が進められている。また,炭化ほう素に代る物質についても検討されている。制御棒材料照射用反射体(AMIR‐8)照射試験では前記吸収ピンをキャプセルに入れて照射する。このキャプセルは照射目的を達成するため燃焼度50・10の26乗cap/立方m,最高1200でも健全性を保持する必要がある。ギャップ幅,装荷位置及びガスプレナム容積を調整してキャプセルの設計を行った。ヘリウムボンド型吸収ピンタイプの中AMIR‐10,11に継続照射を予定しているキャプセルを除き,最終的な設計値を確定した。

In order to extend life of control rods for fast reactors, development of both helium-bonded and sodium-bonded absorber pins with shroud are now under investigation. Also, in development of advanced absorber materials which are alternative materials to B4C, the materials that exhibited better properties in out of pile experiments are needed to do irradiation tests to evaluate applicability as neutron absorber in long life control rods. In irradiation tests of AMIR-8, capsules of two types of helium-bonded and three types of sodium-bonded absorber pins are to be irradiated. In designing these capsules, it is requested that the capsules must possess integrity during irradiation at burnup values of 50 200 10 cap/m at maximum irradiation temperature of 1200C. In order to satisfy above requirements, the design of capsules was done by adjusting the gap size between absorber and cladding, the loading positions and the volume of plenums. The results of design study indicated that, although a target burnup was limited in some capsules, it was confirmed that the irradiation tests are successfully carried out in the other capsules to meet the object of irradiation tests, thereby numerical values in the design of capsules were able to fix.