Plutonium Filters Called Defective Hanford May Have Spewed Pounds Of Particles
Copyright 1996, The Spokesman-Review
It’s a nuclear detective story made possible only by the end of the Cold War.
A Russian scientist living in Tacoma unearths declassified reports that indicate much more deadly plutonium may have escaped from Hanford than the U.S. government estimates.
Dr. Alex Klementiev is an internationally known math and computer modeling expert. He’s helped study Chernobyl’s radioactive legacy.
Now he’s working as a consultant for a Seattle attorney representing thousands of people suing Hanford’s private contractors for exposing them to radiation during the Cold War.
His work challenges a $27 million U.S. government study released in 1994 that said only 28 grams - 1 ounce - of plutonium escaped into the air from decades of bomb-making at Hanford.
Klementiev thinks the real figure is as much as a thousand times more - several pounds of extremely small particles that bypassed plant filters in the late 1950s and 1960s.
His recently completed report was obtained by The Spokesman-Review.
“It is very likely that releases of iodine 131 and plutonium 239 from Hanford are heavily underestimated,” Klementiev said.
Tiny amounts of long-lived plutonium, the most dangerous of the radioactive elements, can cause lung cancer if inhaled. If Klementiev’s estimates prove accurate, it would mean greater long-term risks to public health.
Klementiev’s plutonium report and a companion study of Hanford’s iodine 131 releases are making waves among the few regional health officials who’ve seen them.
If he’s right, dose estimates for thousands of people in Eastern Washington and North Idaho exposed to Hanford releases may have to be revised upwards.
“We’re very interested in Dr. Klementiev’s work,” said Steve West, an Idaho Department of Health official in charge of a three-state working group analyzing the accuracy of the government-funded dose study.
“We’ll be reviewing it in detail, and determining what its implications are,” West said.
Although plausible, Klementiev’s thesis will be hard to document, a Washington Department of Health official said.
“It was a messy process, purifying plutonium, and they kept horrible records,” said Al Conklin, a former Hanford health physicist who analyzed Hanford’s emissions for the dose reconstruction effort.
From 1944 to the early ‘70s, small amounts of plutonium escaped into the air from four Hanford plants that chemically separated plutonium: REDOX, PUREX, AND T and B Plants, according to the 1994 Hanford Environmental Dose Reconstruction Study.
Klementiev thinks those emissions may be underestimated seven to 40 times. But his most dramatic conclusions come from a plant that the dose reconstruction study didn’t consider a significant contributor to airborne plutonium emissions.
It’s a factory with a science fiction name that used to convert liquid plutonium into a solid form for nuclear weapons.
Z Plant, also called the Plutonium Finishing Plant, opened in 1949. The U.S. Department of Energy announced a plan to close it for good last week. But it is still guarded 24 hours a day by SWAT teams because it houses a massive hoard of finished plutonium - 3.9 tons that won’t lose half its radioactivity for 24,000 years.
“Z Plant stack appears to be a major, overlooked source of plutonium contamination,” Klementiev said in his report.
His interest in the old Hanford factory intensified when he reviewed a recently declassified series of reports on missing plutonium from Hanford.
Starting in the late 1950s, a time of major expansion of Hanford weapons production, hundreds of pounds of plutonium that should have been coming out as a finished bomb product were simply disappearing, and Hanford officials wanted to know why.
The “inventory discrepancy” at Z Plant grew to 600 kilograms by the mid ‘60s - more than half a ton.
That large a discrepancy would cause alarm today. In the 1980s, when far smaller amounts turned up unaccounted for at the PUREX reprocessing plant, the Federal Bureau of Investigation combed Hanford’s records before concluding the material wasn’t stolen.
Worried about the missing material, enough to fuel dozens of nuclear bombs, Hanford site contractor General Electric Co. brought in a University of Washington professor to investigate in 1961.
George Brabb, an economist and systems analysis expert, quickly concluded that Z Plant was where most of the plutonium was disappearing.
“I went through the building several times and found that the filtering system was not adequate to capture the vaporized plutonium oxide which was essentially in a gaseous form when released by burning,” Brabb said in a memo.
Plant workers burned plutonium scraps daily to avoid a buildup that could have led to a nuclear explosion.
In one year alone, 1961, “stack losses getting through the filters probably account for 1 to 2 kilograms per year,” Brabb said.
His report was kept secret at the time. It was then appended to a 1977 Rockwell Hanford Co. report on the plutonium losses.
The Rockwell report, and Brabb’s 1961 report, were only recently made public and were not noted in the 1994 dose reconstruction study.
The Rockwell report listed 15 pounds of unaccounted-for plutonium behind Z Plant filters, plus several hundred more that had been buried or poured into trenches outside the plant.
One notorious trench, Z-9 crib, had to be dug up in the 1970s because the Atomic Energy Commission feared enough plutonium had accumulated - 10 pounds in one place - to threaten a nuclear explosion.
Hanford scientists believe almost all the plutonium waste was dumped into the cribs and didn’t become airborne.
“Brabb says the releases into the air are not negligible. That’s his pioneering statement,” Klementiev said.
Taking Brabb’s worst-case estimate of what was going up the stack, “the total estimate of the plutonium 239 releases from Hanford Site becomes equal to about 1,600 curies,” Klementiev said.
That’s more than 1,000 times the official government study’s estimate.
The smaller estimate was based on the assumption that the plant filters worked, Conklin said.
“If you assume the filters worked, you get no more than 1.5 curies total at Hanford. But if the filters failed, that goes out the window,” he said.
“You end up with confusion and mixed numbers, based on who knows what,” he said.
Klementiev said estimates in his report could be revised upwards if still-classified documents on Hanford’s missing plutonium problems disclose even greater losses of plutonium to the environment.
If the plutonium went out the stack of Z Plant, the fine particles likely were carried far downwind, Klementiev said.
If they had fallen near the high-security plant, “the alpha detectors would have warned them,” Klementiev said.
Brabb agreed it probably traveled far.
“If it was as fine as I think it was, it might have gone all the way around the world. Chernobyl’s did,” Brabb said.
Conklin is skeptical of that.
Plutonium is heavy and if it had drifted off the reservation, more of it should be seen from measurements of the lands immediately downwind of Hanford, he said.
“If that much got out, the filtration system had to have failed. That bothers me, because you’d think we’d see some records on that,” Conklin said.
There have been other critiques of the government’s dose study.
Despite its impressive computer modeling effort, “serious questions remain” about the study’s methods and conclusions, the National Academy of Sciences said last year.
Too often, the study failed to base its dose estimates on documented releases, the academy said.
Expert witnesses hired by law firms representing Hanford contractors in the downwinders case are working on a critique of Klementiev’s report.
The contractors are relying on the government’s dose reconstruction report to argue that little plutonium escaped from Hanford.
It’s highly unlikely that an accurate account of how much radiation escaped from Hanford ever will be known, Conklin said.
“It could be anywhere from what the (the dose reconstruction report) said to 1,000 times more. It’s a nightmare to reconstruct the data and figure out who is right,” Conklin said.
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