During the past year, decontamination and dismantlement (D&D) crews with EM’s INL Site cleanup contractor, Idaho Environmental Coalition, have demolished four of the soft-sided buildings used by the Accelerated Retrieval Project (ARP) within the landfill known as the Subsurface Disposal Area (SDA).
Demolition of the ARP II, III, IV and V buildings this year leaves the ARP VII, VIII and IX structures and a soft-sided waste storage building standing on the SDA. Those structures are planned to be demolished by December 2024.
The SDA is a 97-acre, triangular-shaped section of the Radioactive Waste Management Complex, established in 1952 for shallow burial of contaminated INL Site waste. From 1954 through 1970, the SDA accepted Cold War weapons wastes for disposal from sites in Colorado, New Mexico and other waste generators throughout the United States.
In 2008, the DOE, U.S. Environmental Protection Agency and state of Idaho agreed to exhume targeted waste — such as plutonium filters, graphite molds, sludges, and a potentially reactive form of uranium — from a combined area of 5.69 acres from the SDA footprint. This remediation was completed in early 2022, approximately 18 months ahead of schedule.
As with all ARP building removals, crews follow prescribed processes to ensure worker safety and protection of the environment. Prior to demolition, they perform extensive decontamination of the structures and place clean soil over the excavated areas to ensure safe maneuvering.
Each facility is examined for downgrade from an operating hazardous facility to one that can be safely and compliantly demolished. Once downgraded, crews remove all equipment, interior fabrics, and electrical and heating, ventilating, and air conditioning systems. Then they complete final decontamination and apply fixatives. Next, each facility’s skeletal structure is weakened under the guidance and oversight of engineering personnel prior to the structure being pulled down by dual bulldozers. The building debris is then reduced in size and buried within the footprint of the SDA.
Once the remaining ARP buildings are demolished, preparations will begin to install an earthen cover over the entire SDA as the final Comprehensive Environmental Response, Compensation and Liability Act remedy. The evapotranspiration cover will require upwards of 250,000 dump truck loads of soil and rock in what will be the largest single environmental remedy in the history of the INL Site.
-Contributor: Erik Simpson