Title: Hanford nuclear weapons site faces radiation cleanup challenges, delay
Source: USA TODAY
Author: Peter Eisler
Date: Jan 18, 2012
A USA TODAY investigation has found that the troubled, 10-year effort to build the [Hanford, WA] treatment plant faces enormous problems just as it reaches what was supposed to be its final stage.
In exclusive interviews, several senior engineers cited design problems that could bring the plant’s operations to a halt before much of the waste is treated. Their reports have spurred new technical reviews and raised official concerns about the risk of a hydrogen explosion or uncontrolled nuclear reaction inside the plant. Either could damage critical equipment, shut the facility down or, worst case, allow radiation to escape. [...]
“We’re continuing with a failed design,” said Donald Alexander, a senior U.S. government scientist on the project.
The Old Problems
More than 60 of the tanks are thought to have leaked, losing a million gallons of waste into soil and groundwater. So far, the contamination remains within the boundaries of the barren, 586-square-mile site, but it poses an ongoing threat to the nearby Columbia River, a water source for communities stretching southwest to Portland, Ore. And, while the liquid most likely to escape from the older tanks has been moved to newer, double-walled tanks, the risk of more leaks compounds that threat.
The New Problems
- The thicker, high-level waste doesn’t flow according to usual laws of physics; it glugs like ketchup spurting from a bottle. The challenge is to keep it moving: If particles in the material accumulate, they can cause clogs, trapping potentially explosive hydrogen gas or, if too much plutonium masses together, triggering an uncontrolled nuclear reaction that generates extreme heat and radioactivity, threatening workers and the plant’s operation.
- Some of the high-level waste has turned out to be more complex than anticipated, with plutonium particles up to 10 times larger than expected. That has heightened concerns among several scientists, including Tamosaitis and the staff of the nuclear facilities safety board, that the systems designed to churn that waste need further testing to address the threat of hydrogen buildup or a nuclear reaction.
- Alexander, the Energy Department scientist, also worries about the pre-treatment mixing system. Because the mixing jets and vessels were not designed to handle the larger plutonium particles and other abrasives in the high-level waste, he said, the material is likely to erode the vessels’ lining. [...] “If they don’t make any changes and just move ahead, it lasts maybe 10 years.”
Read the report here
Published: January 18th, 2012 at 1:51 pm ET