Several mistakes were made leading up to an incident in November in which radioactive waste was not correctly packaged as it was trucked to a commercial disposal site at Hanford, according to a Nuclear Regulatory Commission report.
Energy Northwest was temporarily barred by state regulators from sending waste to the US Ecology site on leased Hanford nuclear reservation land, after a Nov. 9 shipment from the nuclear power plant near Richland was more radioactive than claimed on the shipping manifest.
Energy Northwest has not had its disposal permit reinstated by the state Department of Health, but is in continuing talks with the agency, according to Energy Northwest.
The NRC conducted an inspection in response to the incident and said this week that it was considering issuing a “white” finding.
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The NRC evaluates regulatory performance at commercial nuclear power plants with a color-coded process that classifies findings as either green, white, yellow or red in order of increasing safety significance. A white finding has low to moderate safety significance and may lead to additional federal inspections or other enforcement action.
The licensee transported a Type A package containing a Type B quantity of radioactive material.
Nuclear Regulatory Commission letter
Before the NRC makes a decision, it will consider information from Energy Northwest at a May 2 regulatory conference in Texas.
The potential white finding involves “the failure to ensure that radioactive contents of a radwaste container did not exceed the radiation level requirements for shipping,” according to the NRC.
It said the cask holding waste trucked to the US Ecology site was approved for transporting waste with about half the radioactivity of the waste the cask contained. the case was about 7 feet tall and weighed about 45,000 pounds.
Energy Northwest has said that although radioactivity was not correctly reported for the shipment, it remained at levels within occupational health standards for workers handling the heavily shielded cask.
The shipment was on the road for about 50 minutes from when it left the Columbia Generating Station on leased land at Hanford until US Ecology confirmed it had arrived about 10 miles away at the disposal site. Most of the drive was on Hanford roads that are closed to the public.
US Ecology surveyed the cask for radiation and rejected it after determining radiation was seven times greater than the shipping manifest for the package declared, according to Energy Northwest.
We have taken a number of immediate actions with regard to how we process and ship low-level material to US Ecology,
John Dobken, Energy Northwest spokesman
The NRC investigation found that the issue started in 2010 when some contaminated items, including filters from routine vacuuming of the used fuel pool, were stored in the used fuel pool but not properly labeled or inventoried.
That led to incorrect labeling in September 2015 that did not appropriately account for the radioactivity of the filters among less radioactive items as shipments were prepared.
The shipment may have included 18 more filters than shipping records indicated, according to the NRC.
Another error occurred when radiation surveys were improperly recorded as the radiation measured on contact with the waste when it was actually a lower level measurement recorded six inches away from the waste.
“We have taken a number of immediate actions with regard to how we process and ship low-level material to US Ecology,” said Energy Northwest spokesman John Dobken.
It has had nuclear industry officials assess its program, provided additional training for the employees who handle waste materials and prepare it for shipment, and put in place new procedures to address issues identified during the recent inspection, he said.