The last of Hanford’s nine plutonium production reactors to be built was the N Reactor. This reactor was called a dual purpose reactor in that it not only produced plutonium for America’s defense program, but it also generated electricity. It was the only reactor of its kind in the country.
N Reactor was so revolutionary that then-President John Kennedy came to Hanford in 1963 to commemorate the start of plutonium production operations as well as break ground for the power-generating component of the facility. President Kennedy’s visit in 1963 took place just four months before he was assassinated in Dallas. His visit to Hanford was one of the few times when the Site’s security restrictions were eased allowing a crowd of more than 30,000 people to visit the reactor and listen to the President’s speech.
The technology associated with the N Reactor was far superior to that which was used to build the first eight nuclear reactors at Hanford. N Reactor had a state-of-the-art cooling system, which required significantly less Columbia River water to be used to cool it during operations. If there was ever a loss of cooling water, N was built with an automatic safety system in place that would shut down the reactor on its own without any operator action required.
The N Reactor operated from 1963 until 1987 when it was shut down for routine maintenance, refueling, and safety upgrades. However, it was never re-started. Instead, DOE placed the N Reactor in standby status, which led to its eventual shutdown without ever going operational again. With more than 24 years of service, the N Reactor was the longest running reactor at Hanford.
When N was shut down, 1 million gallons of contaminated water was left in its storage basin along with approximately one-third of Hanford’s supply of irradiated fuel rods. Workers successfully removed the liquid and sent it to Hanford facilities where the liquid was treated and safely disposed of. The remaining irradiated fuel segments were placed in the K-Basins and have since been moved to the Canister Storage Building where they will stay until such time as a national repository can be built to accept them.
N Reactor was placed in interim safe storage, a process known as “cocooning,” in June 2012. As part of cocooning, workers removed all of the ancillary buildings and sealed up the reactor. The enclosure and roof for N Reactor, the largest at Hanford to date, enclosed the reactor building (85,450 square feet) and the Heat Exchange Facility, which held the steam generators used to produce electricity.