Here is a timeline showing the Tri-Cities' roller coaster layoff history:
1943: Hanford, White Bluffs and Richland are transformed from rural villages with a combined population of about 1,200 into a construction camp of 51,000 workers.
1946: Employment drops to a low of about 5,000 as construction slows after World War II.
1949: The arms race begins when the Soviet Union tests its first nuclear weapon.
1950-56: Four new reactors and two massive plutonium separation plants come on line at Hanford. About 6,500 construction jobs disappear at the end of the boom.
1960s: Hanford employment remains relatively stable through the decade. About 9,500 workers are running eight defense reactors and associated plants at Hanford at the peak of Cold War production.
1971-72: A thaw in Cold War relations brings a halt to plutonium production. Employment at Hanford drops to a low of 6,500 workers before the energy crisis starts to turn things around.
1970s: During the next decade, the federal government starts construction on the Fast Flux Test Facility. The Washington Public Power Supply System begins building three power reactors at Hanford.
1981: Construction jobs tops out at 13,550, then falls to 3,140 by 1984 as the power supply system abandons one reactor, mothballs a second and completes construction on a third.
1980s: A return to plutonium production at Hanford slows the downhill slide in the middle of the decade. Unemployment rates, which jumped to 14.2 percent in 1982, are down to 9.6 percent by 1987.
1988: In February, the Department of Energy announces an end to Hanford's defense mission. The jobless rate is expected to reach 24 percent in 1989.
1990s: Early in the decade, economic revival comes from an unexpected source as the federal government begins hiring for a 30-year Hanford cleanup program. Cleanup jobs peak in December 1994 at about 18,500.
1994-95: Efforts to reduce the cost of cleanup ultimately leads to 5,400 jobs being cut at Hanford.
2001: Bechtel National begins hiring up for construction of the Hanford vitrification plant, a project now estimated to cost $12.2 billion by the time it is required to start operating in 2019.
2005: Bechtel National lays off 1,000 of the 3,800 workers at the vitrification plant in the spring as work slows at key buildings of the plant to allow engineering to advance further ahead of construction, in part because of concerns about earthquake safety. At the end of the year, Bechtel announces plans to lay off about 500 more employees to meet a reduced budget approved by Congress.
2009: The first of $1.96 billion in American Recovery and Reinvestment Act money arrives at Hanford in the spring, and within a week workers are being hired. During the busiest quarter during the next two and a half years, the money is paying for the equivalent of 3,861 full-time workers.
2011: Hanford starts the year with 12,000 workers but nine months later about 2,000 positions have been cut, most because of the end of Recovery Act spending.
2012: The number of workers at Hanford will depend on the budget or continuing resolution passed by Congress. DOE has prepared for that by telling environmental cleanup contracts they can cut up to about 850 workers in addition to those cut in October 2011. In addition, about 210 jobs are expected to be cut by September 2012 as Hanford work along the Columbia River starts to ramp down.