The U.S. Department of Energy (DoE) Office of Environmental Management (EM) is celebrating thirty years of cleanup work at the Idaho National Laboratory site. This work has been carried out to ensure the protection and safety of the underlying Snake Rive Plain aquifer in compliance with state and federal regulations.
The eight hundred and ninety square mile site is located on the ancestral lands of the Shoshone and Bannock Tribes in southeast Idaho. It was established in 1949 to design, build and test nuclear reactors for land, sea and air applications. Fifty-two reactors have been built at the site, most of which were first-of-a-kind. This includes the U.S. Navy’s first prototype nuclear propulsion plant and Experimental Breeder Reactor No. 1 which is the first reactor to produce a usable quantity of electricity from nuclear fission. This reactor is now registered as a National Historical Landmark open to the public.
Four of the fifty-two reactors constructed at the INL are still in operation today: the Advanced Test Reactor (ATR), the ATR Critical Facility, the Neutron Radiography Reactor, and the Transient Reactor Test Facility. The INL is part of the DoE’s complex of national laboratories. They carry out research and development of nuclear energy. The site has also been chosen by NuScale Power and Utah Associated Municipal Systems for the deployment of a small modular reactor plant by the end of this decade.
In December of 1991, the DoE, Idaho, and the Environmental Protection Agency signed a Federal Facility Agreement and Consent Order which outlined a plan to investigate and clean up, if necessary, more than five hundred individual waste area inside the site. The agreement provides the regulatory framework that is still in use for the cleanup of legacy waste that includes contamination from World War II and Cold War-era conventional weapons testing, plus wastes from government-owned research and power-reactor development and testing, used nuclear fuel reprocessing, laboratory research and defense mission at INL other government sites.
Waste sites at the INL consisting of unlined wastewater disposal ponds, debris piles, radioactive groundwater plumes, buried barrels and boxes of radioactive and hazardous waste and even unexploded ordnance, have all been evaluated and most of the cleanup has been completed.
Two of the cleanup projects were explicitly designed to protect the aquifer which lies five hundred and eighty-five feet below the surface. These two projects were the removal of forty-nine thousand drums of radioactive and hazardous waste for an unlined Cold War Landfill known as the Subsurface Disposal Area and the use of vacuum-extraction units to remove solvent vapors from beneath the landfill. The vacuum extraction project was completed early, and the waste removal project is now expected to be completed eighteen months ahead of schedule.
At the northern end of the INL site, more than eight hundred twenty-five gallons of water have been treated with a pump-and-treat system over the last twenty years, and bioremediation is ongoing. This consists of injecting sodium lactate or a similar product into a contaminant plume in the aquifer to create conditions favorable for naturally occurring microorganism to “feed” on the waste.
Construction of the five hundred thousand cubic yard Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Disposal Facility in the early 2000s has allowed waste material from many areas of the site to be consolidated into a single managed landfill that includes several feet of impermeable liners as well as a leachate collection system and lined disposal ponds.
Exhumation of buried waste from the area of the landfill that posed the greatest danger to people and the environment is expected to be complete within the coming weeks.
Fred Hughes is the program manager for EM INL Site contractor Fluor Idaho. He said, “The amount of environmental cleanup work that crews have completed is impressive. The progress is visible, and the aquifer is benefitting from a host of waste remediation projects.”