DEBRIS ACCUMULATION AT NUCLEAR SUMP PUMPS BEING ADDRESSED

摘要

For many years, the Nuclear Regulatory Commission (NRC) has sponsored and published research on the effects that debris accumulation can have on sump screens in pressurized water reactors (PWR). Such debris accumulation could potentially hinder emergency cooling in the event of a coolant pipe break. The commission plans to issue a bulletin requiring PWR operators to assess their sumps and take near-term compensatory actions if they are uncertain their emergency core cooling system (ECCS) containment sumps will operate properly. These near-term compensatory actions could range from increasing the quantity of water available to flood the reactor from external storage tanks to training control room operators to recognize the onset of sump screen blockage and initiate actions to compensate for blockage. In addition, the NRC plans to issue a generic letter this summer requesting that PWR operators evaluate their sump condition and take long-term corrective action as necessary.