About 200 mobile office modules are being moved onto the Hanford site as more office space is needed for workers hired with federal stimulus money, according to contractor CH2M Hill Plateau Remediation Co.

It has warned workers that the office modules could delay traffic at the site through July. Drivers in the Mid-Columbia also may see the modules on the road as they are shipped to Hanford by businesses from Pasco to California.

Hanford is expected to receive $1.96 billion for environmental cleanup work from the American Recovery and Reinvestment Act. That includes $1.3 billion for CH2M Hill, which is doing cleanup work in central Hanford and near the K Reactors.

The $1.96 billion is planned to create or retain about 4,000 jobs over three years.

Hanford done shipping plutonium to S. Carolina

Hanford workers have finished shipping about 2,300 canisters of plutonium from the site to Savannah River,S.C.

Other weapons-grade material still is stored at Hanford. But DOE plans to have the last of it, nuclear fuel that contains plutonium, shipped to Savannah River by October.

The Department of Energy announced in September 2007 that weapons-grade materials would be consolidated in South Carolina and shipments of canisters of plutonium began that fall.

During the Cold War plutonium was produced at Hanford and made into metal buttons the size of hockey pucks at Hanford's Plutonium Finishing Plant to be shipped off site for conversion to weapons use. But at the end of the Cold War, enough plutonium to fill 2,300 canisters was left. Each canister, the size of a large coffee can, can hold almost 10 pounds of plutonium, but the weights vary.

The canisters were stored in a vault at the Plutonium Finishing Plant under armed guard. The Government Accountability Office told Congress in 2007 that if certain weapons-grade material remained at Hanford, security improvements through 2018 that were required after 9/11 terrorism attacks would cost $831 million.