RICHLAND, Wash. (AP) — The nation's most contaminated nuclear site — and the challenges associated with ridding it of its toxic legacy — will be a subject of upcoming hearings and a higher priority in Washington D.C., a key lawmaker said Tuesday.

Democratic Sen. Ron Wyden of Oregon, whose home state neighbors the Hanford nuclear reservation in south-central Washington, said he was troubled by news last week that a radioactive waste tank there is leaking and concerned that a long-planned plant to treat that waste is behind schedule and over budget.

"This should represent an unacceptable threat to the Pacific Northwest for everybody," Wyden said after touring the site. "There are problems that have to be solved, and right now the Department of Energy cannot say what changes are needed, when they will be completed and what they will cost.

Wyden, who has long been a proponent of Hanford cleanup, is the new chairman of the Senate Energy and Natural Resources Committee, which will conduct confirmation hearings for the person nominated to replace outgoing Energy Secretary Steven Chu.

Wyden said he would use those hearings to secure a commitment to finally treat and safely dispose of all radioactive waste at Hanford.

The federal government created Hanford in the 1940s as part of the top-secret Manhattan Project to build the atomic bomb. The government spends $2 billion each year on Hanford cleanup — one-third of its entire budget for nuclear cleanup nationally. And cleanup is expected to last decades.

Central to cleanup is construction of a plant to convert millions of gallons of waste — a toxic, radioactive stew stored in 177 underground tanks — into glasslike logs for safe, secure storage. The $12.3 billion plant is billions of dollars over budget and behind schedule.

In addition, tanks are already long past their intended 20-year life span. Many are already known to have leaked in the past, and last week, Washington Gov. Jay Inslee announced that a single-shell tank could be leaking in the range of 150 to 300 gallons a year, posing a risk to groundwater and rivers.

The Energy Department said it is still unable to determine why liquid levels in the tank are declining, saying it is still investigating the problem.

Monitoring wells around the tank have not detected higher radioactivity levels, said Ben Harp, an Energy Department manager at the site, though contaminants would not be expected to have reached those wells yet. Continued...