The Nuclear Regulatory Commission delivered a letter to Vogtle Nuclear Plant Site Vice President B. Keith Taber on Monday, officially issuing a “white” violation for discrepancies in radiation emission systems discovered during a February inspection.
Inspectors issued a “pre-white” violation when they discovered two emergency radionuclide detection systems had numbers for warning levels crisscrossed. According to regulations, Southern Nuclear, the licensed operator of Plant Vogtle’s two active units, is required to maintain emergency action plans, including emissions monitors.
Two emissions monitoring systems, one for plant vent radiation and another for steam jet air ejector radiation, had their numbers switched. That left the systems with safety benchmarks 42 times different than correct values, according to the NRC. A white violation is characterized as having a low to moderate safety significance.
“These radiation monitors were being relied upon to determine the magnitude of, and for continuously assessing the impact of, the release of radioactive materials, as well as providing criteria for determining the need for notification and participation of local and State agencies,” the letter said.
That means that radioactive releases could have been 42 times lower than what would typically initiate notification of other agencies. Conversely, there could have been radioactive emissions up to 42 times higher than safe levels before area residents were notified or local and state agencies were brought in to help. The NRC violation said Vogtle was in violation from October 2014 to October 2016.
Following the initial discovery and issuance of the pre-white violation, Southern Company sent a response to the NRC. In the letter, the company told the NRC it believed that even with the admitted violation, it believed the redundant and systemic monitors that keep watch for a “nuclear event” would have accurately classified emissions and issued appropriate reactions.
In Monday’s letter, the NRC said, “After careful consideration of the facts, the NRC disagrees with your conclusion. The transposed radiation monitor threshold values degraded your ability to make timely and accurate general emergency and site area emergency classifications.”
“Radiation levels are continuously measured by monitors at the site to determine which, if any, actions should be taken, and there are multiple layers of conservatism when making the appropriate declaration to provide adequate protection of the health and safety of the public,” Southern Nuclear told The Augusta Chronicle when the initial violation was announced. “In this case, when making the calculation, these values on two monitors were inadvertently exchanged.”
Southern Nuclear has 30 days to deliver a response to the NRC.
“The White Finding issued on April 24, 2017 was expected as we have been working with the NRC on this issue and the corrective actions taken to date,” company spokesperson Craig Bell said. “Southern Nuclear took prompt and immediate action to correct the issue to prevent it from occurring again. Due to the immediate action taken by Southern Nuclear when the issue occurred, there are no additional actions that need to be taken at this time. The official notice is part of the normal process the NRC uses for notifications to Southern Nuclear.”
The violation and correspondence between NRC and Southern Nuclear are available at www.nrc.gov.
Reach Thomas Gardiner at (706)823-3339 or firstname.lastname@example.org