WIPP celebrates five years of accepting transuranic radioactive waste
Editor’s Note: On March 26, 1999, the Waste Isolation Pilot Plant (WIPP), 30 miles east of Carlsbad, began accepting transuranic radioactive waste from the research and production of weapons at DOE facilities around the country. In commemoration of this fifth anniversary, Lab News writer Chris Burroughs recently toured the WIPP site with several other Sandians and wrote the following account about her experiences. For more on WIPP, see pages 5 through 7 of this pdf file.
Flat, dry desert land and an occasional land formation punctuate the 30-mile drive from Carlsbad to WIPP. It’s oil and gas country, and wells are scattered around the landscape.
Our tour guide, Sandia DMTS Frank Hansen (6820) — who began working on WIPP repository sciences in 1975 — tells us how 225 million years ago, when early dinosaurs roamed the planet, this part of the world was the Permian Ocean. This ancient ocean deposited enormous beds of salt extending over several hundred miles, including the 2,000-foot salt formation where WIPP is located. He points out skeletal structures of a declining potash industry — mines that at one time were the heart of the Carlsbad economy.
WIPP’s official boundary is four miles by four miles square around the repository, evidenced by a lack of drill rigs on the property. If not for that, it would be difficult to tell when you’ve reached it, as all you see are miles and miles of dry brown desert.
Frank parks the government van in a large parking lot, and we enter a white building that looks much like any Sandia or DOE facility. Entry into the site is guarded, and we are subject to random search before proceeding. The first stop is a large viewing room where we watch a safety video about what to expect underground. We are told we have to wear solid, closed-toed shoes and a miner’s hard hat equipped with a light so we can see (and be seen) in the semi-dark. Following the safety briefing, we are cleared to go to the waste handling building where waste is received, inspected, and moved to a shaft for transfer underground. We learn that as many as 20 trucks carrying waste arrive each week — more than 2,500 waste shipments have been received in the last five years. WIPP has already received 19,000 cubic meters of waste. The waste comes from DOE facilities around the country, with 10,000 cubic meters alone from Rocky Flats in Colorado.
Outside the waste handling building are stored empty stainless steel TRUPACT containers, 8 feet in diameter and 10 feet high, that arrive on flatbed trucks. Each TRUPACT holds up to 14 of the 55-gallon drums carrying waste.
As we enter the building Frank tells us that the waste in the drums is called "transuranic" waste resulting from the production of nuclear weapons. The displayed waste looks like ordinary items found at any industrial site: tools, gloves, and protective suits. Transuranic refers to the "heaviness" of the element. Elements with an atomic number greater than that of uranium (92) are considered transuranic. "Trans" means "beyond," so transuranic can be thought of as "beyond uranium."
The waste forms vary: The display drums exhibit conventional lab debris, such as tools and gloves, bagged in plastic. Other waste packages look substantially different.
The waste handling building is bustling with activity. Waste handlers are preparing the 55-gallon drums for their journey underground. A rope keeps us far away from the containers for safety reasons, but we watch as the workers unload the drums of waste from the TRUPACT-II transuranic waste transport containers. The waste is transported in a seven-pack arrangement, in which seven barrels are bound together with sturdy plastic wrap and transported to the underground the same way.
I wanted to know how they get underground, and Frank says a huge elevator takes them down. It’s the same elevator that transports large equipment, like trucks and excavation machinery. The larger equipment is transported in pieces and reassembled underground.
Seeing this major facility topside and knowing what lies beneath, I marveled at what it took to make WIPP a reality.
"WIPP was a long time coming," Frank says. "Planning started in the early 1970s after the Atomic Energy Commission’s proposition for a ‘Salt Vault’ near Lyons, Kan., was unsuccessful. The Carlsbad city fathers proposed the option to place the nuclear waste repository near Carlsbad, and initially the proposal was to use potash mines. Sandia was engaged early on as the science advisor."
As the scientific advisor for the WIPP, Sandia conducted the performance assessment for the initial compliance certification application and just recently completed another performance assessment for the re-certification application, which is required by regulation every five years or at the demand of the Environmental Protection Agency.
Next we get ready to make the trip 2,150 feet down inside the earth. We go to a cloaking room where we are given the miner’s hardhat with a light and a belt containing a battery for the light and a "self rescuer" that converts carbon monoxide to carbon dioxide in the event of a fire.
We’re also each handed a brass coin with a number on it to place in our pockets. We learn that this is an accountability technique. In case of a mine fire, a person could be identified by the brass coin carried in his pocket.
We walk to an elevator shaft just south of great mounds of salt piled several hundred feet away. The salt has been dug up from more than 2,000 feet below, making way for rooms to store the waste that’s coming. Six of us pile into a yellow metal-meshed elevator, which was the first shaft completed in 1982. We’re "cozy," and I have to hold my camera and purse close to my body. Then we start the descent.
The elevator makes a kind of whinnying noise as it proceeds downward. At about 1,000 feet the sound changes, becoming dampened as the elevator goes from a lined shaft to the unlined salt section. Our ears pop for the first time. As we exit the elevator in a large hallway that serves as a road, the first thing we see is a sign that says, "Welcome to the WIPP underground. You have just entered an environment committed to safety." It reminds all of us — as did the brass coin we received above — that this could be a dangerous place if proper ES&H procedures aren’t followed.
It’s eerie to think this underground roadway, slightly smaller in width than streets above ground, was once all salt — even though we know the walls are salt, the ceiling is salt, and the floor is salt. It’s even more eerie to realize that in a few decades it will be all salt again. The salt is constantly creeping inward in all areas of the repository.
But of course we know that the fact the salt closes in is a primary reason the WIPP site was chosen for the waste repository. In a relatively short period of time the waste will be totally encapsulated by the salt.
We notice that at this entry point the walls are covered by a mesh netting, much like we see in roads going through mountains in New Mexico. And for the same reason — to keep chunks of salt (in the mountains, rocks) from falling on workers.
We see by dim orange-like lighting, scattered industrial lights hanging from the ceiling. We can see but are grateful for the additional lights on our hardhats. At the shaft entrance underground we feel fresh air blowing in. As we continue our trip in the underground tunnels, the air follows us. Frank says the entire underground facility is well ventilated. "The ventilation system," he notes "is designed with a ‘negative pressure’ gradient such that all air flow has a preferential path toward the disposal area and then out the exhaust shaft."
We all hop on a small open cart and drive through the salt tunnels. Every time we turn a corner our driver, Ron Parsons (6820), who serves as facility manager and facility security officer at Sandia/Carlsbad, honks the horn to let people in other vehicles who may be approaching the same point from the other direction know that we are there. Ron pulls a cord and we go through a rubber-flapped steel door. We enter a small area, and Ron pulls another cord, opening another door. These air locks are part of the sophisticated ventilation system that ensures that any radionuclide contaminant would pass "downstream" through a high efficiency filter system.
Off we go down another corridor. We stop outside a panel, which we learn comprises seven rooms where waste barrels are stored. We can’t get too close, but we can see the 55-gallon barrels. The room is the length of a football field, 33 feet wide and 13 feet high. One panel is already filled with waste. The second, where we are, is half filled. A third panel is currently being excavated. Eventually eight such panels will be excavated and filled with waste, then the entry drifts equivalent to two more panels will be filled, and then WIPP will be sealed and the waste left safely underground.
Each panel holds up to approximately 1,500 seven packs of 55-gallon drums arranged in a hexagonal configuration. Placed on top of the drums are huge white bags of magnesium oxide that keep the pH levels high, if brine should ever infiltrate the repository. The magnesium oxide was selected because of a regulatory requirement to provide an engineered barrier in addition to the natural barrier (salt).
We drive through another tunnel and Ron stops the truck. We all jump out. At this site we dislodge some large single crystals of halite, which look like giant diamonds. We each put our salt in plastic bags given to us above to carry home as souvenirs. I couldn’t help it and had to lick one of my fingers. Sure enough, I tasted salt.
We get back in the truck and move on, stopping in front of another room. This, Frank says, is the panel that is completely filled and closed off. The entrance is blocked by a substantial wall of concrete block.
We return to the elevator shaft where we started and see (and hear) huge dump trucks rumbling through, carrying tons of salt recently mined from a panel. We go back up to the surface, but the adventure isn’t quite over. After we turn in our brass coins, hard hats, and belts, we see several flatbed trucks carrying TRUPACT containers lined up and ready to drop off their shipments at the waste handling building. All the trucks have to be checked out by security guards before they can enter the area. I fall behind the group, because I’m taking pictures. Suddenly everyone started shouting for me to come. I hurried over and saw what they saw. One of the trucks was carrying a demonstration TRUPACT that allowed us to view the multiple elements of the shipping container through a window. And indeed, I saw tools, gloves, and protective suits.
The waste being disposed at WIPP is only a small amount of the radioactive waste existing in this country.
The tour is over, and we return to Carlsbad, following the four-lane highway the waste-laden trucks travel to WIPP. I wonder what will this land be like in 10,000 years. Will anyone know that WIPP exists?