According to a report issued on Thursday, the findings were related to "Requirements for monitoring the effectiveness of maintenance at nuclear power plants." In the first finding, NRC inspectors determined that plant personnel had not analyzed the impact to plant risk with the condensate pumps' minimum flow line to the main condenser isolated.
In the second finding, inspectors concluded personnel had failed to conduct an adequate risk assessment prior to securing the "C" feedwater pump.
"Specifically, the inspectors identified that Entergy personnel had not analyzed the impact to plant risk of securing the 'C' feedwater pump."
Though the findings were of very low safety significance, the inspectors determined that the finding had a cross-cutting aspect in the Human Performance cross-cutting area.
Inspectors reviewed 14 aspects of the power plant's operation, including adverse weather protection, fire protection, flood protection measures, maintenance effectiveness, plant modifications and radiation safety.
The inspections were conducted during a period when the plant experienced a number of power downs for maintenance issues.
On April 9, operators reduced power to 35 percent to repair a tube leak in the main condenser. Operators returned
The plant was returned to 100 percent on April 28 and on May 7, power was again reduced, this time to 80 percent, to make repairs to the "C" reactor feedwater pump.
On May 8, operators reduced power to 48 percent to repair a leak on the condensate system minimum flow line.
Though the plant was returned to 100 percent on May 11, a month later, operators reduced power to 40 percent to perform a control rod pattern adjustment and install a temporary patch on a steam leak on the steam seal header associated with the main turbine.
Two days later, on June 13, the plant was returned to 100 percent and then two days after that, it was reduced to 69 percent for a control rod pattern adjustment.
That same day, the plant was returned to 100 percent, but on June 18, power was reduced to 33 percent when the "A" recirculation pump tripped due to an electrical fault associated with the "A" recirculation pump motor-generator set.
On June 30, the last day of the inspection period, the plant was returned to 100 percent.
The findings were related to activities that occurred in May.
On the morning of May 3, an auxiliary operator identified a leak of approximately one to two gallons per minute on the condensate system minimum flow piping at a weld for a drain valve.
The section of pipe that was leaking was isolated, which affected the system's automatic flow control valve.
"Entergy personnel's incorrect assessment of the risk impact of isolating the condensate pumps' minimum flow line's was a performance deficiency that was reasonably within Entergy's ability to foresee and correct and should have been prevented," stated the report.
In the second finding, the NRC determined there was an inadequate risk assessment due to not considering the increased risk of a plant transient when securing a feedwater pump.
On the morning of May 7, plant operators received a low oil pressure alarm for the "C" feedwater pump while the pump was running.
Prior to powering down the plant to troubleshoot and repair the shaft driven lube oil pump, operators performed a risk assessment that did not adequately address the effect of securing the feedwater pump while the three condensate pumps were unavailable due to the isolation of the minimum flow line's automatic flow control valve, stated the report.
Bob Audette can be reached at firstname.lastname@example.org, or at 802-254-2311, ext. 160. Follow Bob on Twitter @shocked60.