Kenneth Fletcher
WC Monitor
3/20/2015
PHOENIX, Ariz.—Recovery of the Waste Isolation Pilot Plant is in full swing after the site’s managing contractor, Nuclear Waste Partnership, began major decontamination efforts last month and hopes to meet a goal this spring to close an underground panel, NWP WIPP Recovery Manager Jim Blankenhorn said here this week. The defense transuranic waste repository has been shut down since incidents in February 2014, but NWP and Department of Energy officials say they are on track to restart initial operations at the plant in about a year. Last month, NWP began decontamination of the underground salt mine to fix the radiological contamination using a notably simple method—spraying it with water. “The salt itself and the water spray appear to be the most effective technique we can use,” Blankenhorn said in remarks at this year’s Waste Management conference. “We are seeing anywhere from a 50-to-100-times reduction after a water spray application.”
This comes after numerous studies by experts and national laboratories researching the various more techniques for cleaning the salt, many of which would be more complex and costly. “That’s due in a large part to the hydroscopic properties of salt,” Blankenhorn said, meaning it absorbs and retains moisture. “If you take a bunch of salt and dissolve it in water, add a bunch of contaminants to it and let the salt dry, it will bind with all of those contaminants and physically hold all of those contaminants in the salt matrix when it dries out. The mine does the same thing.” The contamination is contained in the salt and eventually pulled into the structure of the mine. Once the floor is sprayed and dried, a layer of colored vinyl brattice cloth is laid down to isolate the contaminated salt, and a layer of clean salt is spread out above the cloth. Workers who were waste handlers during normal WIPP operations have undergone training and now are performing the decontamination work.
Additionally, as salt moves slowly in the mine over time, large chunks occasionally scale off of the ceiling or walls and the floor buckles in place. To reestablish the tunnels and panels, those pieces are mined off and slated for disposal, likely in the waste panels that will be closed, Blankenhorn said.
Roof Bolting Progressing, but Majority of Work Still Ahead
With the extended shutdown of the mine, many of the roof bolts used to stabilize the structure have fallen out. Initially, limited airflow in the underground limited the operation of bolting equipment, but bolting operations restarted in November and so far over 1,500 bolts have been added covering about 68 percent of the underground. However, there are still about 4,000 bolts that need to be replaced. “We’ve got some of the more challenging areas to go in terms of bolting, so the number of bolts we have to put in doesn’t match up with the 32 percent of the area we have remaining,” Blankenhorn explained.
Panel 6 Closure Slated for this Spring
The priority is to gain clear access to waste panel 6, which will be the first to be closed since the WIPP incidents. NWP expects to complete closure by May, Blankenhorn said. That open panel is where hundreds of drums are stored that are from the same waste stream as the container that caused the radiological release. Following that discovery, the New Mexico Environment Department released an administrative order calling for the expedited closure of panel 6 and panel 7 room 7, where the radiological release originated.
In panel 6, mounds of salt have being pushed up against the waste stack, and to cut off the airflow a brattice cloth and chain link barrier will be hung from the ceiling and attached to the salt. Next, a metal bulkhead, already in the WIPP underground, will be mounted to cover the opening and anchored in place. In panel 7’s room 7, NWP plans to use the same process, additionally installing the bulkheads on both the inlet and outlet sides.
WIPP officials this week praised the dedication of the site’s workforce after a difficult and uncertain year following the WIPP incidents. “The relationship that I have with my employees has been just amazing,” DOE Carlsbad Field Office Manager Joe Franco said at the conference. “This team has just been open to accepting the challenges that come in, all the folks who have come in to help them. We’re really proud of all of our workforce, they have definitely made a difference this year.”
