The Nuclear Regulatory Commission (NRC) has cited Entergy (NYSE:ETR) for a problem of low-to-moderate safety significance at its River Bend plant in St. Francisville, La.
Better use of a simulator in operator training could have lessened the problems encountered at the plant on Dec. 25, 2014, NRC said in a news release issued Sept. 11.
“Entergy officials failed to ensure that a control room simulator used to train reactor operators was capable of reproducing all of the challenges those operators might encounter during a specific unplanned reactor shutdown scenario,” NRC Region IV Administrator Marc Dapas said. “As a result of this training program deficiency, the operators took some actions that unnecessarily complicated the plant’s response to the unplanned shutdown on Dec. 25, 2014.”
“Specifically, the incorrect simulator response adversely affected the operations personnel’s ability to assess plant conditions and take actions in accordance with approved procedures during the December 25, 2014, scram,” NRC said.
River Bend was operating at 85% capacity Christmas morning when the shutdown occurred. Following the shutdown, some problems were experienced with the plant’s feedwater system, which supplies short-term cooling water to the reactor core. Several electrical circuit breakers also failed to operate properly. Operators took compensatory actions to ensure the plant would remain in a safe shutdown mode.
The NRC held a special inspection to better understand the circumstances surrounding the event.
The team identified an apparent violation of NRC requirements for failing to maintain a training simulator that accurately reproduced the kinds of conditions that control room operators faced on that day, complicating the operators’ efforts to respond to the event. The finding is discussed in a July 7 inspection report. Entergy officials notified the NRC on July 30 that they agreed with the preliminary finding.
The NRC evaluates regulatory performance at commercial nuclear plants with a color-coded process that classifies inspection findings as green, white, yellow or red in order of increasing safety significance. The NRC has determined that the inspection finding has low-to-moderate (white) safety significance which may require additional inspections, regulatory actions and oversight.
The NRC report on the River Bend problem was issued July 7. River Bend is a single-unit boiling water reactor (BWR) with a summer capacity of 975 MW.