The Nuclear Regulatory Commission (NRC) said it had reached a settlement with nuclear plant operator Entergy involving mitigation actions in response to a 2011 leak that allowed an estimated 80 gallons of radioactive water to reach Lake Michigan. The NRC said, however, that it “agreed to disagree” on a whether or Entergy's response to the leak's discovery also included willful disregard of procedures at the Palisades Nuclear Plant in Covert, Michigan.
The NRC said that chemistry analysis of the leakage “revealed several radioactive isotopes including Cobalt-58, a short-lived isotope found in the primary coolant.”
A Condition Report (CR) noted a minor flange leak involving “less than one drop per minute" on a 3-inch piping flange that was bolted into place with carbon steel that was susceptible to boric acid corrosion. The CR, however, did not identify any through-wall leakage or component waste, the NRC noted in a February 2015 letter to Entergy Nuclear Operations Vice President Anthony Vitale.
It took several investigations, including an assessment by Structural Integrity Associates to conclude with certainty that a safety injection and refueling water storage tank, SIRWT was the source of the leak, eventually deciding that it was “essentially 100 percent,” certain the tank was the source of the leakage.
The disagreement comes with the NRC categorizing inadequate reporting done by four workers as “willful.” Entergy defines the problem as a failure of the plant's “organizational safety culture.” It also says it has corrected that problem.
While fining Entergy was a possibility, the company requested the NRC employ a mediation process, which the NRC now says has enabled it to concentrate on corrective actions that will have more valuable outcomes than a fine. “One of the agreements involved not issuing a fine, while Entergy committed to a far greater range of corrective actions than would have been possible through a regular enforcement process that would have resulted in a fine,” said NRC Regional Spokewoman Viktoria Mitlyng.
In lieu of a fine, Entergy has agreed to prepare a report on the lessons learned and to upgrade training to include those lessons. It will also take steps to increase transparency with the public, agreeing to hold public meetings to discuss plant safety and to allow the public to ask questions at those meetings.
Palisades spokeswoman Val Gent noted this week that Entergy "fell short" in its response to the leak. “While this issue did not pose a threat to safe operation of the plant and the tank remained operable during the period in question, we fell short of our standard for excellence in operations,” she said.
The water tank, meanwhile, was “permanently repaired in 2013 and has experienced no further issues,” she added.