Signup for Hanford bus tours this year starts at 6 p.m. Monday on the internet.

Fewer tours are being offered this year, so expect seats to go quickly. Last year, all seats were claimed in five hours and fifteen minutes.

To sign up, go to www5.hanford.gov/publictours. Signup is offered only on the internet. Those without home internet service may use public library internet access.

Although just 40 tours instead of 60 tours are being offered this year, the Department of Energy expects almost as many people to participate because of a change in the registration policy, said Cameron Salony, DOE spokesman.

Too many people were not showing up on the tour days to claim seats, in some cases, months in advance.

DOE's goal is to make sure the buses are full by allowing people who don't get a reservation to sign up to be notified if there are openings, Salony said.

About 1,800 people toured Hanford in 2012, and this year there will be seats for 1,720 people.

In addition, separate tours of Hanford's historic B Reactor also will be offered, with separate registration for those tours expected to be announced soon. Although the Hanford tours include a look inside B Reactor, the tours just for B Reactor allow more time there.

Hanford bus tours will last about four hours and give participants a look at how about $2 billion is being spent each year on environmental cleanup of the site that produced plutonium for the nation's nuclear weapons program.

Participants will get off the bus at four stops: the Cold Test Facility, the Plutonium Finishing Plant, the Environmental Restoration Disposal Facility and B Reactor.

B Reactor was the world's full-scale nuclear reactor, producing the plutonium for the bomb dropped on Nagasaki, Japan, helping end World War II.

The Environmental Restoration Disposal Facility is a massive, lined landfill in central Hanford for the site's contaminated soil and debris. More than 14.5 million tons of low level radioactive and hazardous chemical waste have been disposed of there since 1996.

The Plutonium Finishing Plant made plutonium produced in Hanford reactors into metal buttons the size of hockey pucks for shipment to the nation's weapons production plants. More than half the nation's plutonium for nuclear weapons came through the plant.

The Cold Test Facility is a full-size mockup of one of Hanford's 149 single-shell tanks and is used to test equipment inserted into the enclosed, underground tanks to retrieve the radioactive waste they hold.

-- Annette Cary: 582-1533; acary@tricityherald.com; Twitter: @HanfordNews