Federal officials say a company that manufactured fuel-storage casks at Vermont Yankee violated safety regulations in connection with loose parts found in those casks at other sites.
The Nuclear Regulatory Commission this week finalized its enforcement action against Holtec International. Officials said the company did not follow proper procedures in modifying the design of its casks, which are used to store radioactive material at nuclear plants around the country.
However, the defect was not found at Vermont Yankee. Also, federal regulators and a Holtec executive said the defects were not found to have hindered the casks’ function.
“The loaded canisters do not and have never posed any risk to public health and safety,” Joy Russell, a senior vice president of business development and communications at Holtec, said in a statement issued Friday.
Vermont Yankee stopped power production at the end of 2014, but all of the plant’s spent nuclear fuel remains at the Vernon site due to the federal government’s failure to establish a disposal site.
Last year, then-owner Entergy completed a $143 million project to transfer Vermont Yankee’s spent fuel from a cooling pool to sealed casks. Holtec made those casks and also handled the fuel move.
But that project was halted for nearly two months after a loose part was found in a Holtec cask at the closed San Onofre nuclear plant in California. The part was identified as a shim standoff pin, and another broken pin later was found at Holtec’s facility in Camden, N.J., NRC spokesman Neil Sheehan said.
The Vermont Yankee fuel move restarted last May “following detailed inspections and engineering analyses by Entergy and Holtec,” an Entergy administrator said at the time.
But that wasn’t the end of the issue. The NRC inspected Holtec’s headquarters and found “two apparent violations,” which were finalized this week after consultation with Holtec, Sheehan said.
The NRC found a “failure to establish adequate design control measures” for Holtec’s casks, federal documents say. Holtec also failed to perform certain evaluations before implementing changes.
The design control measure violation was “deemed potentially safety significant,” documents say, because Holtec “did not adequately assess a potentially credible accident and exposure scenario that had the potential for a significant consequence.”
But documents also say a later analysis by Holtec showed that the casks would still perform acceptably even if multiple pins failed. NRC staff arrived at the same conclusion, saying the casks “would continue to be in a safe condition during the entire licensed period of storage.”
The NRC considered a fine of $36,250 for one of the violations but ultimately decided it wasn’t warranted. That’s due in part to “Holtec’s prompt and comprehensive correction of the violation,” documents say.
Sheehan said the NRC will do a follow-up inspection “to verify the effective implementation of Holtec’s corrective actions and methods to preclude repetition” of the cask problem.
Russell, the Holtec executive, noted that the NRC said the company’s violations resulted in “moderate to low safety significance.”
“Holtec remains committed to safety in all we do and will continue to work with the NRC through the enforcement policy process,” Russell said.
In January, Entergy completed the sale of Vermont Yankee to NorthStar, a New York-based cleanup company that will undertake an accelerated decommissioning project.
A spokesman for NorthStar on Friday said the company had no comment on the NRC’s enforcement action against Holtec.
