Mar 4 2005
The U.S. needs to establish a formal, "risk-informed" approach to decide what types and amounts of radioactive waste at U.S. Department of Energy sites should be buried or left in place rather than shipped to a geological repository, such as the one proposed for Yucca Mountain, Nev., says a new report from the National Academies' National Research Council.
"Given the controversy surrounding this issue and the reality that not all of the waste will or can be recovered and disposed of off-site, the country needs a structured, well-thought-out way to determine which wastes can stay," said David E. Daniel, chair of the committee that wrote the report and dean, College of Engineering, University of Illinois, Urbana-Champaign. "Information about the relative risks posed by various disposal options is vital to the decision-making process, and that information must be developed in a manner the public can trust."
The committee did not identify specific wastes that should be approved for alternative disposal. It did find, however, that it is "technically impractical and unnecessary" to remove every last gram of high-level radioactive waste now stored in steel tanks at DOE sites in South Carolina, Washington, and Idaho. Some transuranic waste currently buried at these sites -- which consists of contaminated tools, clothing, and other debris -- may not need to be removed either. The committee did not comment on how waste remaining on-site should be disposed of.
The risk to workers and the environment involved in recovering some hard-to-retrieve waste, as well as the cost of doing so, may not be worth the reduction in risk -- if any -- that is achieved by disposal in a geological repository, the committee concluded. It also noted that techniques exist to separate highly radioactive material from some wastes, greatly reducing the potential hazard of what remains.
The committee recommended that DOE and other interested parties implement a six-step decision-making process based on risk and other factors before any waste is exempted from deep geological disposal. The report describes the characteristics of such a process and provides an example that is compatible with existing regulations, but it does not prescribe a specific process. Each risk assessment should undergo outside technical review, and approval or rejection of the exemption should be in the hands of a separate federal entity as well. It was beyond the committee's charge to say which agency should be given this authority, but it noted that the U.S. Environmental Protection Agency and U.S. Nuclear Regulatory Commission both have expertise in regulating radioactive material.
DOE should form an authoritative and independent group to improve and implement its approach to risk assessment and community outreach, the report recommends. The disposal exemption process needs to take place with as little disruption as possible to current laws, regulations, and agreements, the committee added. It acknowledged that recent litigation has left some of DOE's waste-disposal plans uncertain, but said that a new exemption process is needed regardless in order to foster stakeholder support and avoid ad-hoc approaches, which often result in inconsistent or poorly thought-out decisions.
A second Research Council report issued today says DOE should consider extending the life of facilities used to treat and process radioactive waste at weapons and storage sites in Idaho, South Carolina, Washington, and Tennessee. DOE currently plans to shut down these facilities when they are no longer needed at each site, but the report says they could potentially be used to process radioactive waste from other sites, thereby accelerating overall cleanup efforts. Closing the facilities prematurely could seriously delay the overall cleanup of contaminated sites, the report adds.
The cleanup also could be accelerated by declassifying contaminated equipment left over from the Manhattan Project, according to the report. As long as this equipment remains classified, only employees with security clearance can work with it. Declassification could help shorten cleanup time and decrease costs. In visits to the sites, the committee that wrote the report also noticed that buildings posing little risk were being destroyed despite DOE's declared strategy of targeting the most significant risks first.
The committee recognized that some wastes and contaminated equipment will be left in place. To ensure the long-term safety of what remains, the report recommends that DOE follow the "cocooning" approach now being used to secure reactors at the Washington site. This concept involves stabilizing and monitoring wastes and making adaptations as new knowledge emerges, while keeping all stakeholders clearly informed.
Simplifying and standardizing the requirements for determining what transuranic waste can be shipped to a disposal facility in New Mexico would also quicken the overall cleanup. A previous Research Council report found that some characterization activities are apparently conducted for regulatory compliance and do not seem to reduce risk. Consistent approaches to the preparation of wastes destined for Yucca Mountain are needed as well.
http://www.nationalacademies.org