Photo By David Gray | An SM-1A team member wearing a purified air breathing respirator prepares to enter the...... read more read more
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Summarizing a Complex History
With the recent mobilization at the site of the former SM-1A nuclear power plant on Fort Greely, Alaska, the Radiological Health Physics Regional Center of Expertise, located at the U.S. Army Corps of Engineers’ Baltimore District, began its work toward the decommissioning and dismantlement of its third nuclear power plant, this time located just 175 miles south of the Arctic Circle.
All three of the decommissioning projects under the Baltimore District’s oversight originated from the U.S. Army’s legacy “Army Nuclear Power Program.” The program was established in 1954 and concluded in 1978 after building and operating nine reactors for U.S. Army, Air Force, and Navy projects — but not before it had contributed a lasting impact on nuclear power development in the United States and led to innovations in reactor design, containment and control, lifecycle costs, and health and safety.
After the program ended, the U.S. Army Corps of Engineers (USACE) was responsible for safeguarding, maintaining, and performing environmental radiation monitoring for the three remaining Army deactivated reactors. These facilities, which had been placed in safe storage by 1978, include Fort Greely’s SM-1A as well as the SM-1 on Fort Belvoir, Virginia, and the MH-1A onboard the nuclear barge STURGIS, the world’s first floating nuclear power plant.
Now, the USACE Deactivated Nuclear Power Plant Program (DNPPP) continues this history in its decommissioning efforts through intense focus on the health and safety of the military installations and communities that surround these sites and the workers involved at each phase of dismantlement.
“This work has built a legacy in the history of nuclear power and will pave the way for the future generations of Army nuclear power plants,” said Dave Watters, the Radiation Safety Officer for the Baltimore District.
In 2019, USACE celebrated the completion of the decommissioning and dismantling of the historic STURGIS barge when the final section of the former vessel was brought ashore for processing and recycling at the International Shipbreaking facility in the Port of Brownsville, Texas. By the end of 2023, all large reactor components had been removed from the vapor container structure of the SM-1 on the western shore of the Potomac River at Fort Belvoir, and above-grade demolition was complete.
The DNPPP team now brings the lessons and industry muscle memory from these projects to Fort Greely in its work on the final remaining Army reactor, SM-1A, originally built to test the likelihood of engaging a nuclear power source in arctic conditions while providing power and heat for the utility systems of Fort Greely.
Post-deactivation, Safety, and Regulatory Framework
Since the SM-1A was initially deactivated — including the removal of all control rods, fuel, and liquid radioactive waste — and placed in safe storage in 1973, USACE has continued annual monitoring of the site from both an environmental and radiological perspective and issued annual reports of these findings with no impacts found to date.
Though no nuclear fuel remains, the site was in safe storage for several decades to ensure the occupational safety of work crews involved in the eventual dismantlement. Though minimal risk is expected to the public, safety continues to take center stage in this project, which primarily will involve the removal of large pieces of activated metal.
In the early 2000s, a management plan for the decommissioning of the site began, later including a historical site assessment and a series of characterization surveys which resulted in a formal report and, later, additional characterization efforts as recently as 2020 to ensure all relevant background data was collected.
The team’s extensive 2021 Environmental Assessment led to a Finding of No Significant Impact, which allowed them to present the formal Decommissioning Plan to project regulators at the Army Reactor Office and obtain the Decommissioning Permit. Work by the team is considered self-regulated, meaning the regulatory framework comes from within the U.S. Army and broader government structure, like the Atomic Energy Act of 1954 and the Army Radiation Safety Program. Permits to both possess the site and to implement the decommissioning originate from the U.S. Army Nuclear and Countering Weapons of Mass Destruction Agency, known as USANCA. All standards within this framework comply with Department of Transportation, Nuclear Regulatory Commission, and Environmental Protection Agency standards.
The complexities of this framework aren’t only limited to those placed upon the team by its own chain of command; throughout the course of the project the team has encountered or will encounter requirements imposed by regulations like the Atomic Energy Act, National Environmental Protection Act, Toxic Substance Control Act, Clean Air Act, Clean Water Act, Endangered Species Act, and more from across the Alaska state structure.
“We have engaged actively with the Alaska State Historic Preservation Office,” said Brenda Barber, DNPPP Program Manager. “Because this site is a historic site and it is on the National Registry, we have developed a Memorandum of Agreement where we will preserve all historic artifacts and prepare a Historic American Engineering Record which will document the operation of the site and our current dismantlement activities.”
There are seven plaques of historic importance throughout the facility, and site markers will be developed to leave behind both on the installation and in the nearby town of Delta Junction, signifying the location of Alaska’s original — and, to date, only — nuclear reactor.
Decommissioning Plan and First Steps
Now, with site mobilization underway, the DNPPP team and its contractor began work to implement the decommissioning in compliance with the framework under which they received the permit. As part of the decommissioning, all reactor components, site buildings, and radiologically contaminated soils will be removed, properly packaged, and transported to the mainland United States for disposal.
Throughout the project, the team will complete a significant amount of in-process radiological, environmental, air-sampling, and stormwater surveys before ever reaching the goal of a Final Status Survey that will, in the end, allow the team to demonstrate that the site is ready for unrestricted release.
One of the key components of both the plan and the team’s efforts to ensure timely completion of the decommissioning stems from the need to work year-round, including through the extreme seasonal weather of the Tanana River Valley in interior Alaska. To meet this need, the contractor will construct a large weather enclosure over the site in 2025, enabling exterior work to continue beyond the short summer season while interior demolition begins under controlled containment in the meantime.
The weather enclosure, when complete, mitigates risks to the team by providing a buffer from arctic environment conditions, allows for the storage of equipment when not in use to maintain readiness, and, as a secondary benefit, isolates the worksite from adjacent tenants on the installation. All in-process radiological monitoring will take place both inside and outside this enclosure, and all containment efforts will continue even when the weather enclosure is removed from the site near the end of the project.
Because of the small footprint of the site and the geographically complex, multi-modal transportation required to move the project’s waste to the Lower 48, an additional area on the installation will be set up for waste storage in preparation for coordinated shipping campaigns. When the project is completed, no waste or site components will remain in Alaska.
The first steps to dismantling the site take the form of hazardous materials abatement common when demolishing facilities of this age. Asbestos, lead-based paint, and polychlorinated biphenyls (PCBs) are part of this primary work, which minimizes exposure to the team as the project progresses, part of the knowledge the team has built throughout its previous projects.
“The asbestos abatement team and the demolition team worked meticulously to deal with the asbestos and lead paint at the SM-1 site and to efficiently and safely handle this aspect of the decommissioning,” said Rebecca Yahiel, SM-1 project manager. “The lessons we learned in decommissioning the STURGIS provided valuable insights into this aspect of this project.”
This work is followed by materials and equipment removal not located inside the encasement material or vapor containment structure. These large industrial components include the site’s original steam turbine, generator, bridge crane, and more, making the facility more accessible for future work.
Entering the Vapor Containment Structure and Getting Started
In January of 2024, the team opened and entered the vapor containment structure around the reactor for the first time since 2011. As an example of what future industrial hygiene will look like at the site, the team observed the atmospheric conditions in the structure and the surrounding workspace using five-gas monitors (oxygen, carbon monoxide, VOCs, explosive gases, and hydrogen sulfide) and Draeger tubes. The Draeger tubes were used to monitor ammonia, a potential by-product of the degradation of the AM-9 grout employed as the site’s encasement material.
The team filtered the vapor containment air using high efficiency particulate absorbing (HEPA) filters before discharging it to the atmosphere in the former cold storage facility at the site where additional monitoring occurred. After ventilating the vapor containment for over 72 hours, the team concluded the ventilated structure was safe to enter.
“The team members went in with purified air breathing respirators in order to ensure their occupational safety,” said Barber. “They did the entry in order to perform a safety analysis before additional work could occur.”
Later, once the inner opening was enlarged, the team began drilling sample cores of the AM-9 grout encasement material for additional testing and started sampling background radiological measurements inside the structure.
From an occupational safety perspective, the primary radiological concern stems from Cobalt-60 associated with the operation of the reactor, though its short half-life, just over five years, means the protracted safe storage period ensured it has decayed significantly. Residual Nickel-63, also from the original operation and which has a much longer half-life of over 100 years, will be removed as part of the dismantlement of the primary system components and managed at a long-term disposal facility in perpetuity.
Reaching the Public and Project Legacy
Because of public interest in this historic project and warranted public concern about the radiological material being handled at the site, outreach and education have been important parts of the decommissioning process for the DNPPP team.
Throughout the project’s active recent years, the team has held a series of public meetings and provided regular notifications to inform the installation, nearby stakeholders, and Alaska Native communities about their upcoming work and to allow ample opportunities for feedback and questions. This dialogue has been encouraging for the team, and it helps them better understand the knowledge gaps present when providing future communications. Perhaps most importantly, the DNPPP team has also been able to stress the importance of safety in their work — and the community has been able to learn about the history of the project that operated in their backyard a half-century ago.
“Our team continues to utilize proven controls and precautions to address safety and other engineering details during all stages of decommissioning and dismantlement at these sites,” said Jeffrey Hillebrand, the SM-1A project manager. “This will ultimately serve as an important program and will provide a clear path forward in Army nuclear power.”
Both remaining decommissioning efforts are slated to be complete by 2029, ending the Army’s liability associated with the prior nuclear power plants — MH-1A, SM-1, and SM-1A — and bringing to a close a major legacy in the history of nuclear power. The conclusion of this work demonstrates the full life cycle of this technology and paves the way for future generations of Army nuclear power plants.
| Date Taken: | 08.08.2024 |
| Date Posted: | 08.08.2024 11:42 |
| Story ID: | 478104 |
| Location: | FORT GREELY, ALASKA, US |
| Web Views: | 250 |
| Downloads: | 0 |
This work, Decommissioning the Army's Former Nuclear Power Plant in Alaska, by Thomas Deaton, identified by DVIDS, must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
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