高速実験炉「常陽」性能試験報告書; PT-41主冷却系による熱除去試験

JOYO Start-up test report; PT-41 Decay heat removal by main cooling system

広瀬 正史*; 遠藤 雅行*; 七島 建志*; 藤原 昭和*; 坂井 茂*; 山本 寿*

Hirose, Tadashi*; Endo, Masayuki*; Nanashima, Takeshi*; not registered; not registered; Yamamoto, Hisashi*

本試験は,50MWt「100」時間運転の後に行われたものである。試験の目的は,▲1)原子炉通常運転状態より原子炉停止を行い,2)停止後の崩壊熱を,主冷却系により除熱出来ること,3)上記の間,冷却材温度降下率が-50/hrを越えない,ことを確認するものである。▲試験時の操作は,主に以下の方法で行った。▲1)原子炉停止に当っては,調整棒を1mm/minの割合で挿入し,各ステップで約15分間保持した。▲2)主送風機の停止は10MWtで行い,1MWtで調整棒一斉挿入により原子炉を停止した。▲3)停止後は,2次系のダンパ,ベーンを手動制御し,温態待機の状態に移行させた。▲上記の結果,冷却材温度降下率は-50/hrを越えることなく,原子炉出力50MWtより,原子炉停止を経て,温態待機への移行が完了し,その操作手順が確立された。▲

The purposes of this test are to : (1)verify the procedure for decreasing reactor power from 50 MWt to shutdown, (2)remove the decay heat after shutdoun by the main heat-transport system using the normal procedure, (3)confirm that the rate of temperature decrease does not exceed -50C/hr during the cooldown. At the end of a full power (50MWt) run of 100hours, record steady state plant data. By insertion of one regulating rod, decrease reactor power until PRM indicates 80% (40MWt). Verify that a steady-state condition has been achieved (at least 15 minutes) and repeat data recording. Following same procedure, decrease power stepwise to 30 MWt, 20MWt and 10MWt. Stop the DHX Blowers at 10MWt. Decrease reactor power with one regulatiag rod to 1MWt as indicated on IRM, then shut down the reactor by slow scram. By manual operation of DHX vanes and dampers, decrease coolant temperature as rapidly as possible to the "warm standby" condition (The maximum allowable cooldown rate of 50C/hr must not be exceeded). Test results : (1)The main coolant temperature decrease rate averaged 34C/hr (maximum of 48C/hr) during the cooldown from full power to reator shutdown. During this period, the insertion rate of one regulating rod was approx. 1mm/minute. (2)The average rate of main coolant temperature decrease from shut down to "warm standby" was 35C/hr in manual control.