Demolition work at Hanford Plutonium Finishing Plant has been stopped because of concerns about spreading contamination. Seven homes off-site were surveyed, and more than 200 workers have requested testing.
A government contractor has suspended demolition work at Hanford’s long-shuttered plutonium finishing plant after repeated incidents of contamination spreading from the job site in recent weeks, raising concerns among workers who might have been exposed to radioactive materials.
Radioactive particles were detected on 14 vehicles, and as of Friday 257 workers had requested bioassay tests to determine whether they might have breathed in contamination. Seven homes have been surveyed, but no signs of contamination were found, according to a federal Energy Department timeline of events.
In recent days, the major contractor on the job — CH2M Hill Plateau Remediation Co. — has scrambled to assess the scope of the problems, which likely were exacerbated by high winds that whipped through the site near the Tri-Cities last Sunday when the demolition work was halted.
“Mistakes were made at several levels that created a situation that is unacceptable for worker safety, protection of the environment, and service to our customer,” said Ty Blackford, president of CH2M Hill Plateau Remediation Company, in a written statement.
An Energy Department statement released Thursday said that contaminated areas were found, that they were covered with soil and a “fixative” and that no new contaminated sites were located during the day’s work.
State Department of Health workers have been involved in the incident response, participating in the home surveys and monitoring off the site for signs of contamination.
“We have no evidence that there is any public-health risk,” said John Martell, manager of the department’s radioactive air-emissions section.
But Martell said the concerns about off-site homes makes this an unusual incident. He said he could only recall one other time when the department was involved in surveying homes for radiation in his more than 20 years with the Department of Health.
The work at the Plutonium Finishing Plant is a key part of the broader, decades-long effort to clean up the Hanford reservation, which produced plutonium for the atomic bomb dropped on Nagasaki, Japan, at the end of World War II, and then for the Cold War nuclear-weapons stockpile.
The finishing plant first went into operation in 1949 and shut down in 1989. Through the years, it expanded to include more than 60 buildings involved in turning liquid plutonium into solid material, each piece roughly the size of a hockey puck and shipped to weapons production complexes.
The contamination problem appeared to result from the final demolition work on a structure where plutonium was reclaimed from scrap materials.
According to the Nuclear Regulatory Commission, plutonium primarily emits alpha particles, which have a very short range. But it is toxic, “in part, because if it were to be inhaled it could deposit in the lungs and eventually cause damage,” according to a commission document on plutonium.
This reclamation structure is considered one of the most hazardous areas to take down. Workers who venture into a potential zone of contamination wear respiratory protection. They use water and apply the fixatives — known as soil cement — to try to keep hazardous materials from spreading.
In June, about 350 employees at the job site took cover when an airborne monitor detected an elevated reading. Testing later found 31 workers inhaled small amounts of radioactive substances, according to an Energy Department official.
This month, there were more problems as elevated radioactive contamination levels were found on the lapel samplers of workers in areas where the respiratory protection is not required.
An Energy Department timeline states that on Dec. 8, lapel samplers worn by two workers showed elevated contamination levels. By Dec. 13, increased contamination levels had been found on the lapel samplers of four more workers, and an initial stop-work order was put in place.
“We will not proceed with demolition activities until we resolve this issue,” wrote Blackford in a memo announcing that move.
Work resumed Dec. 14. But it was suspended again Dec. 17, a day when high winds kicked up late in the day.
Tom Carpenter, executive director of Hanford Challenge, which watchdogs the cleanup, questioned the decision to resume the work.
“We are appalled that they restarted work,” he said, “without having fixed the problem. They put more people in harm’s way … Now they are paying the price.”
By Dec. 18, specks of radioactive contamination had been found outside a trailer complex where contract employees on the jobs had office and work spaces. These workers were asked to stay inside until a survey was complete, then moved away.
One of those workers tested positive for breathing in a small amount of radioactive materials during the June incident. This week, she had another test done to see if she had breathed in more contamination. She has yet to receive the results.
“I am not happy at all. I am anxious. This is not something I want to deal with,” said the worker, who requested anonymity out of concerns of job retaliation.
“There is a general feeling throughout the plant that nobody trusts what they are being told. They (management) are not listening to the technicians and workers in the field.”
With demolition on hold, the site work involves surveys and securing contaminated materials, according to an Energy Department update.
A Thursday update indicated that seven of the contaminated vehicles belonged to individuals. Six of those were cleared of contamination, and one was still held in a controlled area.
Seven government vehicles were still awaiting decontamination.