The Energy Department’s Savannah River Site in South Carolina would look for ways to accelerate shipments of transuranic waste to the Waste Isolation Pilot Plant in New Mexico under a proposal being studied by a local advisory board.
The Savannah River Site Citizens Advisory Board is expected to vote on making the recommendation to DOE during its July 23-24 meeting. The recommendation, from board Waste Management Committee Chairwoman Dawn Gillas, would not be binding on the federal agency.
The recommendation says emphasis should be placed on moving legacy TRU waste, packaged prior to February 2014, to the DOE disposal site as soon as possible. An underground radiological accident that month kept WIPP offline for about three years. The document does not discuss specifics of how to speed up shipments.
Before the shutdown, “SRS was well on its way to total de-inventory of all legacy TRU,” according to the board document. “As we understand it now, very few shipments are planned annually to WIPP from SRS from all TRU sources at SRS.”
Roughly 650 cubic meters of transuranic waste are stored in containers of various sizes at SRS, probably the equivalent of about 115 shipments, a DOE spokesperson said by email. The site has also produced seven shipments’ worth of additional waste since February 2014.
Savannah River sent off nine shipments of TRU waste last year after WIPP resumed accepting off-site waste in April 2017, the spokesperson said. No shipments have gone to WIPP from SRS so far in 2018.
“Previously packaged TRU waste is undergoing a rigorous review to ensure the waste as packaged meets the revised waste acceptance criteria” for WIPP, which were tightened after the 2014 radiation release, the spokesperson said. Good progress is being made, but there is also significant pent-up demand across the DOE weapons complex for waste disposal at WIPP.
Meanwhile, the Savannah River Site is downblending 6 metric tons of surplus nuclear weapon-usable plutonium for eventual shipment, as TRU waste, to WIPP. The downblending operation began in September 2016, was then suspended in October 2017 for certain container exams, and restarted in mid-March.
The weapon-usable, non-pit plutonium is mixed into a concrete blend, and is expected to be disposed of at WIPP in the early 2020s.
When it resumed taking shipments in 2017 WIPP focused on larger streams of waste for the sake of efficiency, said a second DOE spokesperson. Both large and small inventories of TRU waste undergo the same review and approval process. The Idaho National Laboratory has most of the shippable waste, and “they are likely to retain around 50 percent of the shipments to WIPP for some time,” the spokesperson added.
WIPP Faces Potential Excess of Waste for Disposal
The amount of transuranic waste already emplaced at WIPP, taken together with known “WIPP bound” material, doesn’t leave much room for more waste under the cap established by the 1992 WIPP Land Withdrawal Act.
That’s a takeaway from a June 26 presentation to a National Academy of Sciences panel by DOE Carlsbad Field Office Manager Todd Shrader
As of June, roughly 93,500 cubic meters of transuranic waste had been placed into the underground disposal site — well over half of the 175,560 cubic meter limit set by the federal legislation. Meanwhile, roughly 78,000 cubic meters more is destined for WIPP from the DOE inventory. This includes waste already in storage or projected to be generated from department facilities around the nation.
That would place the underground disposal facility only 4,000 cubic meters short of the currently allowed maximum. But that is before considering an additional 19,000 cubic meters of “potential waste” for the facility near Carlsbad. This is “waste that may be intended for WIPP but requires resolution of a regulatory or other constraint” before shipment, Shrader said in his slide presentation.
That potential waste could push WIPP to roughly 191,000 cubic meters of material, exceeding the current limit under the Land Withdrawal Act. The Energy Department and WIPP contractor Nuclear Waste Partnership have asked the New Mexico Environment Department to approve a new method of counting waste volume, which could shrink this all-in figure from 191,000 cubic meters to 150,000 cubic meters.
Because many drums are “overpacked” in larger containers, a significant amount of empty space between drums gets counted as waste, Shrader said. The department wants to stop counting the empty space and, in the process, officially reduce the amount of waste already emplaced by 30 percent.
Shrader gave this update to a meeting of a National Academies panel studying whether WIPP is a workable disposal option for downblended plutonium from the Savannah River Site should DOE terminate the Mixed Oxide Fuel Fabrication Facility there. National Academies spokeswoman Jennifer Heimberg said the panel could issue an interim report by the end of the year and a final report in mid-2019.
