Jeremy L. Dillon
RW Monitor
6/26/2015
A defense-only repository would prove cost effective and time efficient compared to comingling it with commercial waste, Secretary of Energy Ernest Moniz said in a May 15 letter to House Energy leaders, released this week. House lawmakers previously questioned the wisdom behind the decision to “de-comingle” the two waste streams, calling it a distraction for DOE from completing its waste disposal obligations. Moniz, though, backed the decision due to the simpler design that the cooler, finite inventory of defense waste provides. “Moving forward with a defense high-level radioactive waste repository that may have a simpler design and present fewer licensing challenges in the near-term could reduce the overall cost and time required to develop future repositories through the experience gained in design, siting, licensing, and development,” Moniz wrote. “The decision to move forward with planning for a separate defense repository does represent a significant change in our nuclear waste management policy, but I believe it is well justified in light of the changed circumstances, experience gained, and lessons learned over the last 30 years.”
Moniz also included in his letter a breakdown of the amount of defense funds appropriated into the Nuclear Waste Fund to help pay for defense waste disposal. House leaders were critical of the de-comingling, partly, because of the wasted defense funds and disregard for previous work on a permanent repository at Yucca Mountain. “With respect to funds spent to date for activities related to the disposal of defense waste, a total of $3.7 billion was appropriated from Fiscal Year 1993 through Fiscal Year 2010 under the Defense Nuclear Waste Disposal account for activities carried out under the nuclear waste program,” Moniz said. “The funding was in part to support activities related to Yucca Mountain, but also to support activities associated with an integrated waste management system including transportation planning and infrastructure improvement.”
The issue of co-mingling deals primarily with whether defense-related high-level waste and commercial spent fuel should continue to be managed together and ultimately go into the same repository. Of the current supply of DOE-responsible waste that would go into a repository, defense waste constitutes 15 percent of the total inventory, according to a DOE official. The Department of Energy produced a report late last year that endorsed the safety and political case for dividing the two waste streams. The report said that such a move would build confidence in a repository disposal process, to meet local state cleanup agreements, and to eliminate the political stalemate surrounding the disposal of commercial waste. Both types of material had been planned to be comingled together in the now shuttered Yucca Mountain geological waste repository, but by separating the two, the Department of Energy would not be limited by the parameters of the Nuclear Waste Policy Act and have more flexibility in design and implementation.
NWTRB Issues Research Recommendations for Defense Waste
The Nuclear Waste Technical Review Board, meanwhile, issued a report last week that recommended DOE take a closer look at how the defense waste packaging would perform in different geologic media. DOE has said that the cooler and well-defined inventory of waste could prove multi-dimensional in the design of a repository, but the NWTRB recommended DOE look at specific rock formations to better assess design models. “Consider waste form performance in different host-rock types after degradation of the waste package in future assessments. Much information can initially be obtained by looking at the performance of commercial SNF and vitrified HLW in different host-rock types,” the NWTRB said. The Board added, “Develop a better understanding of the degradation rates of DOE SNF in potential repository geologic environments, particularly the DOE SNF types that could contribute most to radionuclide release and calculated dose, in order to improve the basis for the separate repository safety assessment.”
The Board also recommended looking at consolidating the waste into smaller packages, which could prove useful for disposal in deep boreholes. “Evaluate approaches, benefits, and costs of repackaging cooler naval SNF into smaller disposal packages,” the Board said. “Conduct research on borehole sealing technology and assess whether more robust engineered barriers might be required for disposing of selected waste forms in deep boreholes.” DOE plans to issue a Request for Proposal next month for a contract to demonstrate the feasibility of deep borehole for disposal.
