The Department of Energy is considering what to do with 14 contaminated railcars and two contaminated locomotives parked near central Hanford since at least 1997.
DOE favors disposing of them, likely at a central Hanford landfill for contaminated waste.
But it will consider whether one of the diesel locomotives and possibly a flatcar might be decontaminated and displayed at Hanford's historic B Reactor.
Discussions of a display are preliminary and the public would not be allowed on the locomotive or flatcar, said DOE spokesman Cameron Hardy.
B Reactor, which produced plutonium for the first nuclear explosion and the bomb dropped on Nagasaki, Japan, now is open for tours and the National Park Service is evaluating its possible role in its future.
Both locomotives and at least 11 of the railcars were acquired by Hanford in the 1940s through the 1960s.
When Hanford reactors were producing plutonium, cask cars were used to haul irradiated fuel from the reactors along the river inland to holding or processing areas. Eleven cask cars now are parked on a rail spur near the 212-R Building, which is just north of central Hanford's 200 West and East Areas.
During World War II and the earliest years of the Cold War, irradiated fuel remained in the cooling pools at reactors for only a few hours or a day before they were loaded into shielded rail cask cars and taken to the 212-N, 212-P and 212-R buildings.
There the fuel rods were stored underwater for a few weeks to as long as 50 days to allow the isotopes to decay before they were transferred to processing plants. The practice was stopped about 1951 and fuel was left in the reactor basins longer to reduce the emission of radioactive isotopes into the environment during chemical processing of the fuel rods to separate plutonium.
Irradiated fuel continued to be transported by rail car, but went to processing plants from the reactors, said Michele Gerber, a Richland historian.
Most of the cask cars, also called well cars, had three large depressions or wells to hold casks that were labeled A, B and C, she said.
The railcars parked on the 212-R rail spur include 10 of those cask cars and one labeled a "tall irradiated fuel cask" that stood on end. It may have been used for experimental materials taken to Hanford laboratories, Gerber said.
The casks are lined with lead and some also contain water used for radiation shielding and mineral oil used to minimize evaporation, according to DOE.
Also parked on the rail spur are two rail tank cars used to transport radioactive liquid waste and a flatbed railcar used to haul miscellaneous equipment.
DOE believes the railcars and locomotives are contaminated with substances that could include radionuclides, lead or PCBs. The flatcar and locomotives have surface contamination, while the fuel casks have internal radionuclide contamination.
If DOE moves ahead with a proposal to dispose of most of the railcars, decisions will be made on a car-by-car basis on how to decontaminate them.
The proposal, detailed in an engineering evaluation and cost analysis report, calls for evaluating whether portions of the railcars or locomotive could be recycled, including to be used for display at B Reactor.
The cask cars would be filled with grout and enclosed in grout using a form built around them. The report discusses shipping the cars to Hanford's Environmental Restoration Disposal Facility, but doesn't limit disposal options to Hanford if another facility to treat and dispose of the waste off-site is available and approved by the Environmental Protection Agency.
DOE is accepting comments until Aug. 13 by email at firstname.lastname@example.org or by mail to Paula Call, U.S. Department of Energy, Richland Operations Office, P.O. Box 550, A7-75, Richland, 99352.
To read the report go to www.hanford.gov and look on the Hanford events calendar for any day through Aug. 13.