U.S. Nuclear Cleanup Carries Major Risks
New Scientist reports in this pretty alarming article that there is a 50-50 chance of a major radiation or chemical accident during the cleanup of the dirtiest nuclear site in the U.S. There are indeed lots of things to clean at the Hanford complex in Washington state: 67 tons of plutonium and 190 million liters of liquid radioactive waste stored in underground tanks. A third of them, dating from the Cold War, have already leaked 4 million liters in the environment, contaminating the groundwater and a river. Meanwhile, officials at the DOE, who'll spend $50 billion between now and 2035 on this cleanup, seem less worried than the different specialists interviewed by New Scientist.
Here is the beginning of the New Scientist article.
There is a 50% chance of a major accident while the US government attempts to clean up its dirtiest nuclear site over the next three decades, a new study concludes. Even without an accident, the groundwater, a nearby river and fish could end up badly contaminated.
A decision to fast-track the rehabilitation of the vast Hanford nuclear complex in Washington State poses dangers and could lead to "costly and time-consuming mistakes", says Bob Alvarez, formerly a senior environmental adviser to the Clinton administration. His study is due to be published in the September issue of Princeton University's peer-reviewed journal, Science and Global Security.
What is the extent of this cleanup?
Over the last 50 years nine reactors at the 1500-square-kilometre site have produced 67 tonnes of plutonium for the US nuclear weapons programme. In 2002 the US Department of Energy (DOE) embarked on a 30-year, $50 billion clean-up, which includes emptying more than 190 million litres of liquid radioactive waste from 177 underground tanks.
In this Hanford overview, the numbers are slightly smaller than the ones provided by New Scientist, but are still worrisome.
Physical challenges at the Hanford Site include more than 50 million gallons of high-level liquid waste in 177 underground storage tanks, 2,300 tons (2,100 metric tons) of spent nuclear fuel, 12 tons (11 metric tons) of plutonium in various forms, about 25 million cubic feet (750,000 cubic meters) of buried or stored solid waste, and about 270 billion gallons (a trillion liters) of groundwater contaminated above drinking water standards, spread out over about 80 square miles (208 square kilometers), more than 1,700 waste sites, and about 500 contaminated facilities.
What is the timeframe for the cleanup?
The DOE accepts that it faces major challenges at Hanford but stresses that since 2000 it has made good progress on what it calls "the world's largest environmental clean-up project". A new treatment plant is more than 25% built and will be ready to take high-level waste by 2011.
The aim is to complete the clean-up by 2035, 35 years earlier than originally planned. This will reduce the danger to the environment, as well as cutting the cost, argues a DOE spokeswoman.
Officials at the Hanford facility don't seem to share Alvarez's concerns. Below is a slide extracted from a presentation given in December 2003 on Hanford cleanup progress to the Hanford Advisory Board. Here is a link to the full presentation (Credit: U.S. Department of Energy, Richland Operations Office).
Alvarez is not sure that this cleanup will be accident-free. Here is his major concern.
According to Alvarez's study, a risk estimate from US Nuclear Regulatory Commission implies that there is a 50-50 chance of a major radiation or chemical accident at Hanford over 28 years of operation. The worst hazard is from a steam explosion at one of the melters used to mix radioactive waste with molten glass.
"DOE's experience with glass melters does not inspire confidence," Alvarez observes. "Since 1991 there have been at least eight melter-related accidents and failures at DOE sites, including two steam explosions."
Please read the rest of the article to discover other potential sources of accident. Frightening, isn't?
Sources: Rob Edwards, NewScientist.com, July 25, 2004; Hanford website