The Nuclear Regulatory Commission has moved forward in conducting the next set of inspections at Oyster Creek Generating Station after it was determined that the power plant had performed within the nominal and expected range for its mid-cycle performance review.
The mid-cycle performance review was completed on Aug. 16. The NRC reviewed the most recent quarterly performance indicators as well as inspection results and actions from July 1, 2011 through June 30, 2012.
The only findings noted in the most recent quarterly report were green, or minor.
“Both were green findings, which are very low safety significance. We have NRC inspectors here on site and their job is to look at everything we do and make sure we’re doing everything right to a T,” plant spokeswoman Suzanne D’Ambrosio said. “We invite these kind of findings because it tells us how we can continually improve.”
The findings also fell under a cross cutting aspect in the area of human performance and decision making, similar to the
“Those human performance flaws are extremely serious because you’re dealing with a plant that’s on its last legs and has a history of safety problems and a corroding containment,” Janet Tauro of Grandmothers, Mothers and More for Energy Safety previously said of the annual assessment. “You can’t have performance issues. You have to be perfect every single day and that’s impossible.”
Oyster Creek employees strive for excellence, D’Ambrosio said.
“We will always strive for excellence but as humans, things will happen. That’s why we have inspectors and written procedures and processes and continuous training,” she said.
Due to the findings, plant employees will have additional training and process reviews, D’Ambrosio said.
Initiating Events
The NRC found that Exelon did not perform an adequate operability determination of Average Power Range Monitor 7 prior to restoring in on March 24.
The monitor was declared inoperable on Feb. 2 and declared operable on March 24 without documenting a surveillance test to demonstrate its operability. It was operated through April 3, when it failed in the same manner and was declared inoperable.
The finding was determined to be a more significant safety concern because equipment requires a full screening to ensure inoperable equipment is not being restored to an operable status.
Although, the report later stated that the finding is of “very low safety significance” because it would not contribute to a reactor trip or impact other mitigating equipment.
Mitigating Systems
Inspectors found that Exelon did not enter the correct technical specification and take the required actions when both isolation condensers were made inoperable in order to perform corrective maintenance.
Exelon operators should have entered a more specific specifications for when both isolation condensers are inoperable, which would have required the initiation of an immediate shutdown instead of allowing 30 hours to reach cold shutdown, the report said. Therefore, the finding was “more than minor.”
It also affects the Mitigating Systems cornerstone objective of “ensuring the availability, reliability and capability of systems that respond to initiating events to prevent undesirable consequences.”
Because the finding did not result in a loss of functionality or operability and was not potentially risk-significant due to a seismic, fire, flooding or severe weather, it was deemed of very low safety significance.
Upcoming Inspections
Because Oyster Creek had a positive mid-cycle review, additional upcoming inspections were set.
The inspections include flooding and seismic walkdowns, which was initiated according to the post-Fukushima Near-Term Task Force Recommendations.
“We have here on site a team who are tasked with addressing all the post Fukushima testing and surveillance and subsequent actions as a full time job,” D’Ambrosio said. “It’s not a process where you go in and look at something and your done. It’s going to be a very thorough and rigorous process.”
The seismic walkdowns focus on adverse anchorage conditions, adverse seismic spatial interactions and other seismic conditions, according to the NRC’s Inspection Manual. The walkdowns confirm that there aren’t potentially adverse anchorage conditions such as bent, broken, missing or loose hardware; corrosion that is more than mid surface oxidation; or visible cracks in the concrete near the anchors.
The flooding walkdowns are to confirm the following, according to the NRC’s Inspection Manual:
- Cable and piping trenches and other penetrations to structures, systems and components important to safety, including underground rooms, are not pathways for external ingress of water
- Adequate water detection and warning systems are available, if credited in the current licensing basis
- The effects of elevated water levels and severe weather conditions would not impair support functions or would not impede performing necessary actions given the weather conditions
- Other factors at multi-unit sites would not prevent implementation of flood protection measures
- The procedure or activity can be executed as specified
The seismic and flooding walkdowns are just a piece of the post Fukushima project, D’Ambrosio said.
“We don’t want to leave any questions or any room for doubt. We want to make sure the information we have and the plan we have in place is solid and secure and designed to keep Oyster Creek at the pinnacle of safety no matter what Mother Nature throws at us,” she said.
