The NRC won’t fine International Isotopes for license and regulatory violations the company made last year that contributed to the release of cesium-137 last year at a Seattle hospital facility.
In a letter of enforcement published on Tuesday, NRC staff dinged International Isotopes with two violations: failure to have appropriate administrative procedures to mitigate the risk of contamination release and the inappropriate approval of procedures that decreased the effectiveness of the radiation safety program.
While 13 people on site and seven floors of the University of Washington’s Research and Training Building at Harborview Medical Center were contaminated in the May 2019 incident, there were no overexposures. According to spokesman Victor Dricks, that means members of the public who were exposed to the cesium-137 weren’t exposed to more than the regulatory limit of 100 millirem per year.
The industry workers who were exposed received doses of less than 5 rem per year, Dricks said. Dricks said the NRC came to this conclusion after reviewing the licensee’s own investigation.
In the incident, International Isotopes inappropriately used a mobile hot cell and power tool to remove a sealed Cesium-137 source from its source holder in a blood irradiator.
“[T]he NRC determined that because the cesium-137 sealed source that was inadvertently breached contained a large amount of activity relative to the regulatory limits (either public or occupational) for inhalation dose, one or more personnel overexposures could have occurred under only slightly different circumstances,” staff wrote.
Because of the amplified risk, staff labeled the violations as Security Level II, which would normally incur a $24,000 base civil penalty. However, the commission declined to impose the fee because International Isotopes had taken “significant actions to terminate all field service activities and remove them from your license.”
International Isotopes was removing the cesium source under a program funded by Department of Energy’s National Nuclear Security Administration. The agency has since stopped using International Isotopes for this sort of work, and the company has decided to get out of the source-removal business entirely.
In a teleconference held in August, the company said it had already paid civil penalties from the Washington state Department of Health for the accident and the full shutdown of its source recovery business. More than $1 million in field service contracts have been terminated and the company has over $350,000 in internal costs from its recovery.
Meanwhile, the contaminated building could reopen in about a year or so, a senior Department of Energy official estimated in late August.
