Safer Hanford demolition planned
Demolition of the Plutonium Finishing Plant at Hanford could restart Tuesday, more than 15 months after the tear down was halted because of an airborne spread of radioactive contamination.
Many changes have been made since December 2017 to make sure that work at the radioactively contaminated plant will be done safely as demolition resumes.
“There can be no repeats of releases of contamination outside posted radiological boundaries,” said Tom Teynor, Department of Energy project director for the plant.
In 2017, 42 workers inhaled or ingested small amounts of radioactive contamination from demolition of the plant. Several workers’ cars were contaminated with radioactive particles, including two that were driven home before the contamination was discovered.
Very small amounts of radioactive plutonium or americium were found to have spread from the plant for miles, with contamination found near the Columbia River and not far from public Highway 240.
Limited work already started
In September contractor CH2M Hill Plateau Remediation Co. was allowed to restart some work at the plant, but only the less hazardous work.
Crews began removing contaminated demolition debris left on the ground and unpackaged at the main part of the plant after the December halt to most work.
That work was completed last week, with close to 2,500 tons of debris loaded up and packaged for disposal at a central Hanford landfill for low-level radioactive waste.
Now crews are ready to resume demolition.
The restart is planned for Tuesday, although it may have to be delayed if the weather is too windy to work safely and control contamination.
The initial demolition will be on the remaining parts with the lowest levels of contamination, with the first planned work the tear down of one of the vaults where plutonium was once stored.
The plant was used during the Cold War to process two-thirds of the plutonium for the nation’s nuclear weapons program. Plutonium came into the plant in a liquid solution and was turned into solids that could be sent to a weapons production plant.
New safety measures in place
“We’re satisfied that they have procedures in place to allow the lower-risk demolition to proceed,” said Stephanie Schleif, project manager for the plant for the Washington state Department of Ecology, a regulator on the project. “Like everyone who follows the Hanford cleanup, we’re eager to see this work proceed safely and be completed.”
Workers have used the same safety precautions to load up contaminated debris in recent months that are planned for the restart of demolition using heavy equipment in the open air.
The boundaries around demolition areas where contamination might be expected and extra precautions are taken were expanded.
Fixative is sprayed on debris or disturbed surfaces at the end of each day.
Communication has been increased, both with the workers on the project and workers on other projects nearby in central Hanford.
Significantly more monitoring is being done for contamination spread, both in the air and on surfaces.
The controls have been working well, said Mark Hughey, CH2M deputy vice president for the project.
Demolition schedule has slipped
The restart of demolition initially was planned for mid October 2018 but was delayed because of employee turnover on the project. About 48 union workers at the project had the opportunity to transfer to jobs with higher pay at the Hanford tank farms.
Work was slowed to allow new workers to train and to practice work, including loading and wrapping uncontaminated material at a mock-up site at Hanford.
An unusually snowy winter at Hanford further further slowed work to load up contaminated debris.
The new schedule projects completing the demolition work on less contaminated portions of the plant in early July.
Later that month demolition on more highly contaminated parts of the plant will resume.
It will require Hanford regulators — the Department of Ecology and the Environmental Protection Agency — to lift a stop-work order issued after the contamination spread.
“We will continue to work with the Department of Energy in reviewing plans and work packages for resuming the high-risk portion of work left at PFP before we will lift our stop-work with the EPA,” Schleif said.
An independent management review also is planned before CH2M and DOE officials sign off on the higher risk work.
All demolition could be completed and some remaining highly contaminated demolition rubble from a annex to the plant loaded up in late September.
The annex, the Plutonium Reclamation Facility, had been nearly completely demolished in December 2017 when the contamination spread was discovered.
However, keeping to the schedule is not a priority.
“The contractor is committed, from (President) Ty Blackford down to the work in the field, to proceed at a safe, deliberate speed,” Teynor said.