NNSA Sandia Site Office Manager Patty Wagner says the shipments mark a significant milestone on the journey to remove nuclear materials from Sandia.
“NNSA has worked closely with Sandia since the decision was made in 2004 to reduce the nuclear footprint at this site,” says Wagner, “and I am very pleased that, despite several obstacles, Sandia has successfully met its commitments and accomplished the effort without incident.”
The waste being removed is the byproduct of nuclear defense program research and weapons production. Much of the waste removed from Sandia came from programs completed in the 1980s.
Depending on the level of radioactivity, the waste was packaged for disposition in lower-level contact-handled waste containers (CH-TRU) or higher-level remote-handled waste containers (RH-TRU).
Both the RH-TRU and CH-TRU disposed of at WIPP consist of tools, rags, protective clothing, and other materials contaminated with radioactive elements that have atomic numbers greater than uranium (transuranic).
RH-TRU waste produces a higher dose rate than CH-TRU waste at the surface of the disposal container, but when transported RH- and CH-TRU waste have the same dose rate limit on the outside of the shipping casks due to lead shielding.
Before any of the waste left for WIPP, the Environmental Protection Agency (EPA) and New Mexico Environment Department (NMED) reviewed Sandia’s documentation for determining the physical and chemical characteristics of the waste, to ensure its safe disposal at WIPP.
Remote-handled (RH-TRU) removal
Beginning in the summer of 2011, employees in Non-Reactor Nuclear Facilities Dept. 1387 and WIPP Central Characterization Project (CCP) personnel worked for more than a year in the Tech Area 5 Auxiliary Hot Cell Facility (AHCF) to analyze and repackage the remotely handled RH-TRU waste for shipment. CCP personnel on site were able to certify as safe the RH-TRU waste, so it could be sent directly to the WIPP facility for disposition.
The AHCF, a small, heavily shielded concrete box, was established specifically to process and disposition legacy nuclear material and waste. A crane brings waste materials into the cell through a roof door. Crew members examine the waste material through thick, leaded windows, and use glovebox-style manipulator arms to examine the material and take samples.
During the RH-TRU project, workers confirm that the waste materials have been correctly described and documented, and then repackage the waste, which is then removed through the cell’s roof door.
On Dec 16, 2011, WIPP received the first of eight planned RH-TRU shipments from Sandia. WIPP is designed to safely isolate defense-related TRU waste from people and the environment. Operating since 1999, WIPP receives waste temporarily stored at sites around the country, and permanently disposes of it in rooms mined out of an ancient salt formation 2,150 feet below the surface.
RH-TRU waste will make up only about 4 percent ─ or 7,080 cubic meters ─ of the total volume of waste received at WIPP.
Contact-handled (CH-TRU) removal
Prior to the removal of remote-handled transuranic waste, employees in Radioactive Waste/Nuclear Material Disposition Dept. 4139 removed all of Sandia’s lower-level CH-TRU waste.
Beginning in December 2010, Sandia packaged and sent its CH-TRU waste to Idaho’s Advanced Mixed Waste Treatment Project, where it was certified to ensure that the waste was of a level appropriate for CH-TRU disposal.
The first of three CH-TRU shipments left Sandia in December 2010, with the second one leaving in March 2011, and the final CH-TRU shipment in October 2011. The CH-TRU sent as part of the first two shipments was then certified in Idaho and shipped to WIPP for disposal. Drums from the final shipment were recently certified in Idaho and shipped to WIPP.
CH-TRU waste must emit less than 200 millirem per hour on contact, on the side of the drum. This relatively low level of gamma radiation means that, when properly packaged, the drums can be handled directly by workers in appropriate gear.
Removing legacy wastes a priority
DOE National TRU Program Director J.R. Stroble says the shipment is significant to WIPP.
“Our goal is to reduce the nation’s nuclear waste footprint and we routinely receive shipments from around the country,” says Stroble. “This first shipment of RH-TRU waste from Sandia begins the final stages of eliminating legacy TRU waste from a DOE site in New Mexico.”
Nationally, DOE has prioritized removing legacy waste from small-quantity sites, such as Sandia. Removal of the TRU waste was also a contract incentive (PBI3) for Sandia, so completing the removal met a contractual requirement that was given high priority by NNSA.
For Sandia, proper disposition of legacy waste reduces programmatic and regulatory risk associated with the continued storage of such waste forms. Another benefit is that it demonstrates the opening of a pathway for TRU waste so future projects that may generate similar materials have a viable path out the door.
Additionally, DOE also assured New Mexico legislators that removal of legacy waste in New Mexico would be a priority. In addition to waste removal at Sandia, DOE has overseen the removal of 913 shipments from Los Alamos National Laboratory in northern New Mexico for final disposition to WIPP.
The last four shipments RH-TRU shipments are expected to leave Sandia in March, and will conclude the cleanup of all legacy TRU wastes at Sandia.