A reactor at the Hanford site has been “cocooned” for the first time in a decade.
The addition of a new steel enclosure for the 1950s reactor is an “iconic change to the landscape” at the nuclear reservation along the Columbia River and helps
protect the river, said John Eschenberg, president of Department of Energy contractor Central Plateau Cleanup Co.
Eight of the nine plutonium production reactors that line the Columbia River in Eastern Washington are being put in temporary storage for up to 75 years to allow radiation in their core to decay to lower levels before a permanent solution is attempted.
The newest cocoon, with its straight sides and sloping roof, creates a new look for the Hanford skyline, much different from the other cocooned reactors which retain much of the original shape of the reactors.
Completion of the cocoon over the K East Reactor leaves just one more to be cocooned at Hanford.
The K East Reactor was number seven, with its twin, the K West Reactor, not expected to be cocooned until about
2030.
The ninth reactor, B Reactor, will remain unsealed and open for tours as part of the
Manhattan Project Historical National Park.
From World War II through the Cold War Hanford
produced about two-thirds of the plutonium for the nation’s nuclear weapons program.
Production stopped with the end of the Cold War, and now the nation is spending for than $2.5 billion a year on environmental cleanup work at the 580-square-mile nuclear reservation by Richland.
For the K East Reactor a new form of temporary storage was
used that Hanford officials expect to save money and better protect the reactor as it waits for final disposition in the coming decades.
No decision has been made on the final plan for disposing of Hanford’s defunct reactors, but allowing radiation to decay will provide safer conditions for workers then.
In Hanford’s traditional cocooning, reactors are torn down to little more than their radioactive core, any openings are sealed up and the roof is replaced.
NEW TYPE OF REACTOR COCOON
But for the K East Reactor, a new, free-standing structure 123 feet tall and nearly 154 feet wide was built over the reactor for the first time.
The new method of cocooning should better protect the nearly 80-year-old concrete of the reactor from wind, sand and cycles of freezing and thawing that take a toll on Hanford structures, Eschenberg said.
It also should reduce the need for roof maintenance.
Although the new steel enclosure was designed to last 75 years, Eschenberg said final disposition of the reactor is not likely to be done that late. No decision has been made on what
final disposition will be.
Every five years Hanford workers will enter the reactor to check on
its condition.
New lighting installed within the reactor and between the steel cocoon and the
original reactor walls will help make that easier as workers check the condition of the concrete, look for any rodents or other animals, and make sure there has not been any intrusion of water.
Not only was the work to build the cocoon done safely, but the project was completed a few months ahead of schedule and significantly under the original budget, said Brian Vance, manager of the DOE Office of River Protection and Richland Operations Office.
Cocooning the reactor was budgeted at $13.5 million, but was completed for $9.5 million, Eschenberg said.
The project came in under budget despite the nation’s supply chain issues over the last year, with escalating costs of steel, he said.
The project used 620 tons of structural steel.
Good planning, efficient work and the performance of workers and Eastern Washington companies kept costs in line, he said.
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