According to technician Mike Geffre, who works for contractor Washington River Protection Solutions, an inspection was made of a pit under the tank. Its water samples had an 800,000-count of radioactivity and a high dose rate, which means that workers must reduce time spent in the area.
“Anything above a 500 count is considered contaminated and would have to be disposed of as nuclear waste,” Geffre explained. “Plus, the amount of material we’ve seen from the leak is very small, which means it’s a very strong radioactive isotope.”
If the waste escapes the tank and gets into the soil, it may reach groundwater and potentially the Columbia River.
“This is really, really bad. They are going to pollute the ground and the groundwater with some of the nastiest stuff, and they don’t have a solution for it,” Tom Carpenter, executive director of the Seattle-based advocacy group Hanford Challenge, a watchdog group that conducts environmental sampling to monitor for radioactive and chemical contamination, told AP.
There are 177 tanks holding up to 56 million gallons of waste, 149 of which are single-shell. Six of those tanks were discovered in February to be leaking at a rate of about 1,000 gallons annually.
AY-102 is one of Hanford’s 28 tanks with two walls, which was installed when single-shell tanks began leaking and some of the most radioactive liquid in those tanks was pumped into the sturdier double-shell tanks. The tanks are now beyond their intended life span.
Two radionuclides comprise much of the radioactivity in Hanford’s tanks: cesium-137 and strontium-90. While both take hundreds of years to decay, exposure to either can increase the risk of cancer.