A LARGE environmental cleanup project in the US is making use of a significant number of Fieldbus Foundation solutions. Handled by ABB, with Pepperl+Fuchs providing the physical layer components, the effort at the Hanford facility needs interconnection solutions for more than 10,000 Foundation Fieldbus devices. The overall I/O count on the project is in excess of 50,000 channels.
The 1518 square kilometre Hanford site is located along the Columbia River in south-eastern Washington State. A plutonium production complex with nine nuclear reactors and associated processing facilities, Hanford operated for more than 40 years, beginning in the 1940s with the Manhattan Project. Today, under the direction of the US Department of Energy, Hanford is engaged in the world's largest environmental cleanup project, along with a number of overlapping technical, political, regulatory, financial, and cultural issues.
Physical challenges at the site include more than 190 million litres of high-level liquid waste in 177 underground storage tanks, 2100 metric tons of spent nuclear fuel, 11 metric tons of plutonium in various forms, about 750,000 cubic metres of buried or stored solid waste, and about a trillion litres of groundwater contaminated above drinking water standards, spread out over about 208 square kilometres, more than 1700 waste sites, and about 500 contaminated facilities.
Hanford’s workforce of approximately 11,000, equipped with an annual budget of about $2 billion in fiscal year 2003, is expected to complete cleanup operations by 2035, or possibly 2025.
It is using vitrification, a proven technology used in the US and Europe, to immobilise radioactive waste in an exceptionally sturdy and stable form of glass to isolate it from the environment.
The waste will be pre-treated to separate the high-level waste from the low-activity waste. Silica and other glass-making materials are added to the waste, which is then heated to nearly 1093 degrees C in an electric melter. The molten glass is then poured into large stainless steel canisters, which are cooled for a few days before being welded shut and decontaminated.