Used nuclear fuel management specialist NAC International could face civil penalties for failing to adhere to federal regulations in updating the design for one of its storage casks, according to the Nuclear Regulatory Commission.
The federal agency cited two apparent violations on Sept. 3 in submitting the findings of a February 2020 routine inspection of NAC’s corporate offices in Norcross, Ga. The document was posted Wednesday to the NRC website.
Both seeming breaches involve NAC’s pre-December 2016 update to the design of its MAGNASTOR used-fuel cask, according to the NRC report. The change involved the concrete overpack for MAGNASTOR, which was then designated CC5 – “a reinforced concrete structure with a structural steel inner liner and base.”
“The apparent violations related to performing design changes to an NRC approved design and not subjecting the changes to design control measures commensurate with those applied to the original design and implementing a proposed change that would result in a departure from a method of evaluation described in the [final safety analysis report] used in establishing the design bases or in the safety analyses are further described in the applicable sections of this inspection report,” the regulator said.
First, the company was found to have failed to meet the requirement under agency regulations to ensure that design changes are subjected to the same control measures applied to the original design. Management did not employ a specific computer model used on the original MAGNASTOR design “for the assessment of acceleration values for a design basis tip-over accident of the MAGNASTOR CC5 spent fuel cask,” the report says.
A tip-over accident is just what it sounds like – a used-fuel storage cask toppling over. The design basis is the level of an accident that a nuclear facility must be able to incur without endangering public health and safety.
Second, NAC did not obtain a required Nuclear Regulatory Commission amendment for its MAGNSTOR certificate of compliance before proceeding with the design change. Such an amendment is mandatory under federal regulations in any change from a method of evaluation laid out in the final safety evaluation report for setting the design basis or in other safety evaluations. That also involved the failure to use the computer model in the cask design change, the report says.
Both apparent violations are being considered for escalated enforcement, according to the Sept. 3 letter to NAC President and CEO Kent Cole from Andrea Kock, director of the NRC’s Division of Fuel Management. That process can result in financial penalties against an NRC licensee.
The report does note that the NRC inspection team overall determined that NAC operations were sufficient in areas including quality assurance, document controls, and auditing.
NAC has 30 days from the date of the letter to file any written response with the agency, including potential disputes with the findings or detailing corrective actions taken to address the issues. Management also has the options to request alternative dispute resolution via a mediator or a pre-decisional enforcement conference to discuss its perspective on the matter.
At deadline Friday, NAC had not responded to questions about the regulatory findings.
MAGNASTOR (Modular, Advanced Generation, Nuclear All-purpose STORage System) is designed with capacity to hold 37 spent fuel assemblies from a pressurized water reactor, or 87 assemblies from a boiling water reactor.
A fully owned subsidiary of Japanese manunfacturing and engineering corporation Hitachi Zosen since 2013, 52-year-old NAC International offers systems for storage and transportation of used nuclear fuel, along with associated consulting services. The company is supporting a project the Interim Storage Partners project in West Texas for centralized, interim storage of spent fuel from nuclear power plants.
The company last year asked the Nuclear Regulatory Commission to waive over $632,000 in fees for the review of its MAGNATRAN spent-fuel transportation package. NAC said that portion of more than $2 million in fees resulted from poor work by an agency contractor that created more work and extended the eight-year proceeding. That matter had not been resolved as of Friday.
