AUGUSTA, Ga. – EM joined government agencies, regulators, and others from around the world to discuss best practices and challenges of in situ decommissioning (ISD), sometimes defined as entombing a contaminated facility in concrete.
The Technical Information Exchange Meeting held in Augusta, Georgia late last year brought together more than 50 attendees from:
- Agencies — DOE, including headquarters, Savannah River Site (SRS), Richland Operations Office at the Hanford Site, and Oak Ridge; Atomic Energy Canada Ltd. (AECL), U.K. Nuclear Decommissioning Authority (NDA), Japan Atomic Energy Agency, and International Atomic Energy Agency;
- Regulators — DOE Office of Environmental Health Security and Safety, U.S. Environmental Protection Agency, U.S. Nuclear Regulatory Commission, South Carolina Department of Health and Environmental Control, Canadian Nuclear Safety Commission, U.K. Environment Agency; and
- Other entities — Savannah River National Laboratory, URS | CH2M Oak Ridge, Canadian Nuclear Laboratories, Magnox Ltd, and Sellafield Ltd.
In the past decade, DOE used ISD for the U Canyon at the Hanford Site; Loss of Fluid Test facility and the old calcine facility, the first entombment effort at a DOE site, both at the Idaho Site; and the P and R reactors and Heavy Water Components Test Reactor at SRS. Participants in the exchange visited SRS, where they viewed facilities planned to be closed using ISD.
“While ISD is not the optimum approach for all contaminated facilities across the DOE complex, it has been used to great effect at some DOE sites,” said Andy Szilagyi, Director of EM’s Office of Infrastructure and Deactivation & Decommissioning. “ISD has the potential to accelerate site closure safely and cost-effectively if it is applied in an appropriate manner.”
The definition of ISD and its implementation in the U.S. and other countries varies and is the subject of debate. Proponents of the approach consider it cost-effective and beneficial because it minimizes worker safety concerns, eliminates the need to remove contaminated equipment from a facility, and consolidates contaminated material in one place. Opponents say that following ISD, the decommissioned facility is a de facto long-term waste disposal site didn’t undergo the formal process typically used for such a site.
Exchange participants identified common critical issues to revisit in working groups. Those groups will identify actions to implement in the next one to two years to help each country establish ISD as a safe and cost-effective decommissioning alternative.
Dr. Anna Clark, Head of NDA’s Decommissioning and Remediation, described the exchange as “excellent” and found it useful to consider the spectrum of decommissioning projects captured under the international ISD umbrella, from leaving a lightly-contaminated pipeline in the subsurface to the permanent entombment of a contaminated facility in concrete.
“Debates about the pros and cons of these different ISD projects have prompted some extremely valuable discussions between me and my colleagues from the U.K., Clark said. “We look forward to sharing our learning as we continue to decommission the U.K. nuclear sites.”
Dr. Frank Gibbs, Vice President of AECL Decommissioning and Waste Management Oversight, said the meeting exceeded his expectations.
“As we saw during the excellent tour of Savannah River Site, effective implementation of ISD offers considerable safety and schedule, and cost benefits,” Gibbs said.