A few things from today’s Nuclear Regulatory Commission’s Event Reports page:
1. Yesterday morning, operators at the Waterford nuclear power plant in Louisiana took Essential Chilled Water Pump B out of service for maintenance. Actions taken at that time also “rendered motor driven Emergency Feedwater Pump B inoperable.” This left the reactor with only one operable feedwater pump, and it was not rated to be the sole operating feedwater pump. “The remaining operable Emergency Feedwater Pump A is a design rated 50 percent pump; therefore, this event could have prevented fulfillment of the Residual Heat Removal safety function.” Despite the pump failure, the plant’s single reactor continued to operate at 100 per cent.
2. AREVA’s nuclear fuel fabrication facility in Richland, Wasington, yesterday issued an update on an event that occured on July 22, 2011. A criticality drain originally declared to be in a degraded condition has now been determined to have been in a failed status, a more serious descirption than the company initially reported. The new Event Report now desribes the condition as “a failed item relied on for safety.” The drain has now been modified to prevent buildup of radioactive materials.
3. And also yesterday morning, the Fort Calhoun nuclear power plant reported that some of the conduits penetrating two rooms did not have the proper insulation to prevent floodwater from entering containment. From the report: “Three fittings into room 19 (auxiliary feedwater and plant air compressors) and fittings into room 56E (electrical switchgear) were found to contain no filling material.” An additional conduit was also inadequately protected from flooding: “One additional fitting into room 56E that was thought to be capped was found to be open with a sheet metal box covering the inside access thereby obscuring inspections.” Fort Calhoun was shut down for much of the summer due to rising water from the Missouri River.