Nuclear waste leak suspected from double-walled tank at US plant

An underground tank holding some of the worst radioactive waste at the most contaminated nuclear site in the US is suspected to be leaking into the soil, The Associated Press reported.

According to the US energy department, workers at Washington state's Hanford Nuclear Reservation detected higher radioactivity levels under tank AY-102 during a routine inspection Thursday, the report said.

Spokeswoman Lori Gamache said the department had notified Washington officials and was investigating the matter further. An engineering analysis team would conduct additional sampling and video inspection to determine the source of the contamination, she added.

According o the report, AY-102 is one of two tanks with two walls, which were installed years ago after leaks sprung in single-shell tanks. Some of the worst liquid contained in those tanks was pumped into the sturdier double-shell tanks. The tanks were now beyond their intended life span and according to the energy department's announcement last year that AY-102 was leaking between its two walls. However, it then said no waste had escaped.

According to CBS News correspondent Ben Tracy, a whistleblower provided several pictures to the TV channel on Friday pertaining to the Hanford Nuclear Reservation. One of the pictures dated 12 June, 2013, showed green material, thought to be radioactive waste leaking from a tank at Hanford.

The double-walled tank was supposed to securely store the waste until it could be processed into a more stable form for long-term disposal.

Commentators say any breach of the tank's outer layer would be a huge setback for the troubled effort to clean up the most contaminated nuclear site in the US, a task costing $2 billion in taxpayer money each year.

According to a statement released by the energy department, it was in the process of assembling an engineering team to try to determine if the tank was the source of the contamination.