Highly radioactive pool of CESIUM-137 AND STRONTIUM-90 – Hanford USA

Deep sleep Warren Cornwall*, Science  10 Jul 2015: Vol. 349, Issue 6244, pp. 132-135  DOI: 10.1126/science.349.6244.132 “………..CESIUM-137 AND STRONTIUM-90 are the hot potatoes of the nuclear waste world, packing a powerful radioactive punch in a relatively short half-life of 30 years. At Hanford, there’s barely enough to fill the back of a pickup truck. Yet it contains more than 100 million curies of radiation, roughly one-tenth the radiation in the core of a large nuclear reactor. And it produces enough heat to power more than 200 homes.

To prevent the tubes from causing trouble, they sit under about 4 meters of water in what resembles a giant swimming pool, emanating a blue glow known as Cherenkov radiation as high-energy particles slam into the water. The 1974 building housing the pool is past its 30-year life span, according to DOE’s inspector general. Bombarded by radiation, the pool’s concrete walls are significantly weakened in places. Some of the tubes have failed and been stuck inside larger containers. In a review of DOE facilities conducted after the 2011 disaster at Japan’s Fukushima Daiichi Nuclear Power Station, the department’s Office of Environmental Management concluded that the Hanford pool had the highest risk of catastrophic failure of any DOE facility, for example in a massive earthquake, according to a report from the department’s inspector general. DOE says it plans to move the pool waste into dry casks for safer storage, but it hasn’t said when.

It’s an urgent situation and a huge safety risk,” says Tom Carpenter, executive director of the watchdog group Hanford Challenge in Seattle, Washington, which has been critical of DOE’s efforts to secure the waste.

Borehole advocates point out that the Hanford tubes are less than 7 centimeters in diameter, narrow enough to fit down a hole without extensive repackaging. All could fit into a single shaft. Other military waste could also go down a borehole, advocates add. One candidate is plutonium that DOE has extracted from dismantled nuclear weapons. Most of it is currently stored as softball-sized metal spheres at a DOE facility in Texas. In contrast to Hanford’s cesium and strontium, the plutonium is fairly cool, but extremely long-lived, with a half-life of 24,000 years. DOE is considering other options for the plutonium, including turning it into fuel for nuclear reactors or combining it with other nuclear waste and burying it. But boreholes could be an effective way to put it far out of the reach of anyone trying to lay their hands on bombmaking material……….http://science.sciencemag.org/content/349/6244/132.full