What may have been the most famous glove box in radiological processing history is now gone.
CH2M Hill Plateau Remediation Co. workers have removed the glove box that exploded Aug. 30, 1976, peppering Harold McCluskey with shrapnel — shards of glass, resin beads, nitric acid and radioactive americium 241.
He survived, coming to be called Hanford’s Atomic Man. Years later he would give talks about the accident, demonstrating his lingering contamination by holding a clicking radiation detector up to the side of his face.
The explosion happened in the tight quarters of the Americium Recovery Facility at Hanford Plutonium Finishing Plant. It was used to recover americium from waste material at the plant for possible industrial or other use.
It is one of the smallest facilities in the Department of Energy complex, but has been one of its largest problems, said John Silko, a DOE senior physical scientist.
The five glove boxes in the room were meant to safely contain radiological material. Workers would look through leaded glass windows and reach into the boxes with gloves attached to ports. They ranged from near the floor to high enough that workers needed step ladders.
When the WT-2 Glove Box exploded, it spewed radioactive material into the room. Photos taken after the accident show the floor scattered with broken glass, rings from the glove portals and resin beads that were being used in chemical work within the glove box.
Some debris blew back into an adjacent glove box and more debris spread contamination throughout the control room.
“(What) was in the glove box now was everywhere,” said Mike Swartz, CH2M Hill vice president.
Getting the Plutonium Finishing Plant, where plutonium was made into metal pucks to be shipped off site for weapons production, ready to tear down has had many challenges, said Ron Skinnarland of the Washington Department of Ecology, a regulator on the project. But “this is one of the hardest parts of the job,” he said.
Just four workers typically could be in what’s come to be called the McCluskey Room at one time. The aisle between the glove boxes was just 6 to 7 feet wide, and workers wore new-to-Hanford protective suits. The puffy, air-filled suits keep workers cool and are pressurized to better protect workers.
Work had to be carefully planned to make sure employees spent as little time as possible in high contamination areas. But there was no way to avoid the remains of the WT-2 Glove Box, which workers had to walk past as they entered the room until it was removed. Workers are closely monitored to make sure the radiation they are exposed to stays within conservative limits.
“Every time they make an entrance, it is an experiment,” Silko said at a recent Hanford Advisory Board committee meeting. “They always end up with a surprise.”
In the WT-3 Glove Box, workers found 26 lead bricks stamped with the word “Battelle” stacked in a corner. They were covering up a spill that had left that part of the glove box radioactively contaminated.
The bricks were removed one by one, and that part of the glove box was cut up and packaged individually.
Work was done in 2010-11 using economic stimulus money to remove two of the glove boxes, which were numbered four and five.
Efforts resumed in late summer 2014 to remove the next glove box, the one with the lead bricks. Then workers started on the exploded glove box, completing removal this spring.
Just one glove box remains, WT-1, which has some of the debris from the exploded glove box. Work to remove it is expected also to be completed this spring.
Inside the glove box that exploded was a 3-foot-long steel ion-exchange column that held resin beads, and about 136 grams of americium with 450 curies of radioactivity.
“It was a heck of a lot of americium,” said Eugene Carbaugh, a senior health physicist for Mission Support Alliance at Hanford, during a recent presentation.
The ion exchange column had been loaded before workers walked off the job on strike for four months. During those months hydrogen gas built up in the column.
On the night shift of the explosion, McCluskey had been instructed to add nitric acid to the column.
He knew something was wrong when he heard hissing and saw brown fumes as he stood on a step stool in front of a leaded glass window, Carbaugh said. The gloves were warm to the touch, which was not normal.
McCluskey had just turned his head to warn a co-worker, when an explosion peeled the column open like a Pillsbury biscuit can, Carbaugh said. It had enough force to break the windows and to bulge the sides and top of the glove box.
Debris, acid and americium sprayed the right side of McCluskey’s face.
“He received the largest recorded deposition of americium,” Carbaugh said.
McCluskey was blinded from the acid that sprayed his eyes, and a co-worker helped him walk from the room. A decontamination shower was available, but workers were afraid of what being sprayed with cold water would do to his heart. He had undergone coronary artery bypass surgery six months earlier.
Instead, he was taken to a sink to have his eyes, face and shoulders flushed with water. An alpha radiation detection instrument was brought in, but his contamination was off its scale.
The path from the sink to a waiting ambulance were lined with plastic, and he was walked out about 90 minutes later. The ambulance also had been layered with plastic and the driver and two nurses were wearing full-face respirators.
He was taken to a small building that had been constructed behind what is now Kadlec Regional Medical Center, where he lived for 79 days.
Much of the treatment he received would be standard today, Carbaugh said. But then a medication used to capture the americium in his blood stream, zinc DTPA, required an appeal to the Food and Drug Administration for investigative approval. It was granted in just five days.
McCluskey would take it intravenously for the next four years.
He also was scrubbed with mild soap and water, doing much of the washing himself on his acid-injured skin. For four months, a medical team used tweezers to pick out pieces of metal, plastic, cloth and glass that worked their way out of his skin. The largest was a quarter-inch piece of glass in his eyebrow, Carbaugh said.
“The decontamination was extended, extensive, difficult and it was never complete,” Carbaugh said. “That’s how he became known as the Atomic Man.”
By day 79 his medical team’s biggest concern was whether he would spread americium if released. He, his wife and his dog moved into a 20-foot trailer parked outside Kadlec until officials deemed it was safe for him to return home to Prosser in January.
“The medical treatment administered allowed him to live a reasonably normal life,” Carbaugh said. His eyesight was permanently impaired and he did not drive again. But the zinc DTPA kept the americium from concentrating in his liver and killing him through liver failure.
McCluskey died in August 1987 of congestive heart failure during a visit to Western Washington. A pathologist, who initially did not know his history, found no malignancies in his body.
Had McCluskey lived more than 11 years after the explosion, it is possible he could have developed them, Carbaugh said.
The accident investigation found that the ion exchange column should not have been shut down while loaded with americium. Analyses were not done on changes to the process, including switching from aluminum nitrate to concentrated nitric acid for flushing and increasing the column loading from 15 grams of americium to as much as 150 grams.
The excessive degradation of resin exposed to radiation led to an explosion when it was combined with the nitric acid, the investigation concluded.
With the final glove box soon to be removed from the Americium Recovery Facility, workers will still have some final tasks to prepare the facility for demolition along with the rest of the Plutonium Finishing Plant. Work still must be done in the facility’s tank room and piping gallery and in the control room.
The contaminated materials and items removed from the facility will be packaged to be disposed of at Hanford’s central landfill for low-level radioactive waste or at the Waste Isolation Pilot Plant in New Mexico, which is used for defense waste contaminated with isotopes including plutonium and americium.