抄録
If a Loss-of-Coolant-Accident (LOCA) inside the reactor building were to occur, it could generate debris. Debris that could accumulate on the sump screens would increase head loss across the resulting debris bed and sump screen. Furthermore, materials within containment could dissolve or corrode, and result in precipitation or corrosion products which could add to the debris load and further increase head loss across the debris bed and sump screen. This head loss might be sufficiently large such that it might exceed the net positive suction head (NPSH) margin of the RIS and EAS pumps, which would challenge the safety function of RIS and EAS system.This paper describes the impact of chemical effect on sump strainer head loss in a power plant in China. The test fluid used representative plant coolant chemistry, and the test fluid temperature was controlled to simulate the post-LOCA plant coolant temperature profile. Water samples were taken periodically during the test and then analyzed for elemental concentrations of the Al, Si, Na, Ca. Following the tests, we can conclude that no visible precipitation was noted during the test. The aluminium coupon was corroded, but did not form precipitation in the solutions during the test. The available Ca ions in TSP environment were potentially related to the Ca_3(PO_4)_2 precipitation. Overall, Ca ICP levels were reducing over time which may indicate that the Ca was used to form precipitate. Although the chemical reaction occurred and precipitation formed during the test, it didn`t have remarkable impact on the sump strainer head loss.
