In 1999, Oregon shipped a 1,000-ton nuclear reactor vessel 270 miles up the Columbia river, then buried it in Washington

On August 8, 1999, a 907-metric-ton reactor vessel from Oregon's Trojan Nuclear Power Plant reached the Hanford Reservation near Richland, Washington, after a 270-mile trip up the Columbia River. The vessel had been removed from the plant as one piece, transported on a specially built barge and then hauled overland to a burial site. The shipment involved the reactor vessel and its activated internal components. The uranium fuel had already been removed. The U.S. Nuclear Regulatory Commission described it as the first U.S. shipment of an intact reactor vessel that still contained its activated core internals.

According to the NRC's account of the project, the vessel traveled for about 36 hours from the Trojan site north of Portland to the Port of Benton in Washington. It then continued by road to the disposal facility at Hanford. The unusual shipment was part of the decommissioning of Trojan, Oregon's only commercial nuclear power plant. The plant had stopped operating several years earlier, and its remaining radioactive components had to be removed from the site.

Why Trojan's reactor had to be moved


Trojan began commercial operation in May 1976 with a generating capacity of 1,130 megawatts, and Portland General Electric permanently shut the plant in January 1993 after a series of technical problems and a decision not to continue operating it. The decommissioning process involved removing large components from the plant. The reactor vessel presented a different problem because it contained activated internal structures from years of operation.

Engineers developed a plan to remove it intact rather than dismantling the vessel into smaller pieces. The approach reduced the amount of handling that was required and avoided sending numerous separate radioactive packages through the transportation system. The reactor vessel was more than 42 feet long and had a diameter of more than 17 feet. Its carbon-steel walls were between 5 and 10 inches thick. A Project Management Institute account of the Trojan removal project states that workers drained the vessel and filled it with about 200 tons of low-density cellular concrete. Steel shielding was added before transportation. The outside was decontaminated and coated, and the package was prepared for shipment as a single unit.

The reactor traveled by barge, not truck

The first part of the journey took place at Trojan itself, where engineers removed the reactor vessel from the containment building and placed it on a specially designed transporter. The transporter moved only about a quarter of a mile to a Columbia River loading area. There, the reactor package was transferred onto a custom-built 240-foot barge. Two tugboats handled the river journey, while U.S. Coast Guard vessels provided an escort and maintained a safety exclusion zone.

The route was about 270 miles, which also included four sets of locks operated by the U.S. Army Corps of Engineers. The NRC says the vessel reached the Port of Benton after roughly 36 hours on the river. Regulators also had to approve a transportation package that did not fit neatly into existing testing requirements. The NRC, the U.S. Department of Transportation, Washington state authorities and the Coast Guard all had roles in approving different parts of the operation. The NRC says the reactor vessel and its internals required special approval for disposal at a shallow-land burial facility, and a detailed exposure-pathway analysis was conducted before the disposal was approved.

Hanford became the final destination

The reactor package was moved onto land for the final leg after reaching the Port of Benton. The special transporter used 20 axles and 320 wheels, and it traveled roughly 30 miles from the port to the U.S. Ecology disposal facility at Hanford. The reactor was not simply dropped into an open hole, since project records describe a controlled disposal process. A few days after arriving at Hanford, the package was placed inside a trench about 45 feet deep and covered with earth. The NRC reported that the reactor vessel contained more than 55.5 petabecquerels of radioactivity, with cobalt-60 the predominant gamma-emitting isotope. That radioactivity came largely from neutron activation of the vessel and its internal structures during years of reactor operation.

The NRC estimated that disposing of the vessel and its internal components as one package would avoid more than 40 radioactive shipments compared with alternative approaches. According to the Oregon Department of Energy, the reactor vessel and steam generators were shipped by barge to the U.S. Ecology low-level radioactive waste facility at Hanford. The agency's decommissioning timeline identifies 1999 as the year the reactor vessel and its internal components were removed in one piece.

The Trojan plant itself continued through the wider decommissioning process. The containment building was demolished, the cooling tower was eventually imploded, and the site underwent surveys before regulators approved its release for unrestricted use in 2005. The reactor vessel's destination was different, as it remained buried at Hanford as part of the site's radioactive waste disposal operations. Trojan's spent nuclear fuel also followed a separate path, since Oregon's energy department says 791 spent fuel assemblies were transferred into 34 dry-storage casks at the former plant site in 2003. Those casks remain there while the federal government has yet to establish a permanent national repository for spent nuclear fuel.

The 1999 shipment therefore dealt with one part of Trojan's radioactive legacy. The reactor vessel traveled 270 miles by river, crossed onto land at the Port of Benton and was placed in a 45-foot-deep trench at Hanford. The power plant that once generated electricity near Portland was eventually dismantled, but some of its nuclear material remains in storage in Oregon while the reactor vessel itself remains buried in Washington.