Work is under way to cocoon Hanford's N Reactor, the nuclear reservation's most modern plutonium production reactor and one that repeatedly made national news.

It was the nation's only reactor to produce both plutonium and power, drawing President John F. Kennedy for a visit shortly before his assassination. N Reactor was back in the news 25 years ago this week, when the Chernobyl nuclear reactor unit 4 exploded and the Department of Energy was pressured to shut down the last Hanford reactor.

Today, N Reactor is fast becoming just a part of history. The heat exchanger building attached to the reactor has been cocooned and work has begun to cocoon the reactor, DOE contractor Washington Closure Hanford announced Tuesday.

Cocooning is the process DOE is using to put all of Hanford's plutonium production reactors, except the historic B Reactor, into long-term storage. The reactors are torn down to little more than their radioactive cores, the remaining structures are reroofed and openings are sealed up. Then they are left for up to 75 years to allow radioactivity to decay to more manageable levels.

"This is the sixth reactor we'll have cocooned at Hanford and certainly the largest by far," said Cameron Hardy, DOE spokesman.

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