A radiologically contaminated piece of equipment left the Hanford nuclear reservation and was taken into north Richland by mistake, according to a message sent Wednesday afternoon to Hanford employees.
The equipment, a “spreader bar” that distributes weight while hoisting items, had been used at Hanford’s Plutonium Finishing Plant.
Most work has stopped at the plant since a spread of plutonium was discovered there in December. Then several employee cars were contaminated and some employees inhaled radioactive contamination.
In the most recent incident. a worker assigned to Mission Support Alliance, which is responsible for rigging at Hanford, removed the equipment from an area at the plant’s complex where radiological contamination might be present without checking it for radiation. The area was designated a radiological buffer area.
The action was taken without the knowledge of upper level managers at the plant, which is being demolished by CH2M Hill Plateau Remediation Co.
The truck carrying the bar left the plant July 26 and drove to two places on the Hanford site and then to a contractor facility in north Richland.
The truck later returned to Hanford and the bar was unloaded at an outdoor yard in central Hanford and moved inside a building used to store hoisting and rigging equipment.
The bar was checked there, and “low levels” of plutonium and other radioactive contamination were discovered, according to the message to employees.
No radioactive contamination has been found at any place where the truck traveled, according to the message.
The Washington state Department of Health, which is responsible for public protection off the Hanford site, has requested records of the surveys done for radioactive contamination and will review them.
The spreader bar has been moved into an area for contaminated material at Hanford.
The Department of Energy is working with its contractors and the Washington state Departments of Health and Ecology to determine what actions will be necessary to protect workers and the public, according to the employee message.
CH2M has changed its protocols for releasing materials from radiological buffer areas to maintain accountability and prevent contaminated equipment from being moved out of areas controlled for contamination, employees were told.
A management assessment is planned to start Monday, with DOE evaluating whether the correct procedures and controls are in place to resume demolition of the Plutonium Finishing Plant.
The rigging bar incident will be a focus during the assessment, the message to workers said.
The December contamination spread at the Plutonium Finishing Plant came after an earlier spread in June.
In the June incident, an air monitor alarmed and workers were ordered to take cover indoors. Checks of workers later found 31 had inhaled or ingested small amounts of airborne radioactive particles.
After the December spread was discovered, 11 more workers were discovered to have small amounts of contamination radioactively decaying inside their bodies from inhaling or ingesting the particles.
Specks of contamination were found after the December incident on seven worker cars, with at least two driven home and one of them a rental car. Checks of several worker homes found no radioactive contamination.
Contamination also was found on government vehicles used at the site.
Small amounts of radioactive contamination were found to have spread from the plant for miles in December and earlier, with contamination found near the Columbia River and at the site’s Rattlesnake Barricade just off public Highway 240.
The plant was used during the Cold War to process plutonium, which came into the plant in a liquid solution, into a solid form that could be shipped to plants that produced nuclear weapons for the nation.
The work left the plant highly contaminated, and contamination spread during its demolition in the open air using heavy equipment. In December, demolition was being done then on of the most contaminated part of the plant, its Plutonium Reclamation Facility.
Hanford officials announced plans in late July to resume demolition of the plant if DOE and its regulators conclude the work can be done safely, based in part on results of the management review that is set to start on Monday.
Work could restart after Labor Day to remove contaminated demolition debris left on the ground and unpackaged at the main part of the plant after work stopped in December.
Then in October demolition of part of the main plant that has low levels of contamination could begin.
Higher risk demolition work could restart in January, including tearing down a production area of the main plant. The final step will be removing demolition rubble left at the plant’s Plutonium Reclamation Facility, with work possibly completed by summer 2019.
CH2M plans several changes as work resumes, including more air monitoring and not allowing demolition rubble to accumulate for more than a day before packaging it for removal.