Accident at US repository highlights need for tougher nuclear safety monitoring

Call for better oversight of nuclear-waste storage Accident at US repository highlights need for tougher safety monitoring, say experts.Nature, Declan Butler 13 May 2014 A serious accident in February at the United States’ only deep-storage repository for nuclear waste might never have happened had the government not disbanded a key independent scientific body charged with oversight of the safety of the facility.

The Waste Isolation Pilot Plant (WIPP), carved out of a salt bed 655 metres below the desert near Carlsbad in New Mexico, is run by the Department of Energy (DOE) and stores low- and medium-level military nuclear waste, containing long-lived, man-made elements such as plutonium and americium. But there are politically controversial plans to store far hotter high-level waste at the site. Nuclear-waste experts say that the accident — in which a container is thought to have ruptured or exploded — along with management errors and a lack of oversight at WIPP, highlight the need for an independent risk assessment of any proposed expansion.

The facility was opened in 1999 and is designed to operate for a few decades, after which it will be sealed forever. The accident on 14 February released moderate levels of radioactivity into the repository, as well as small amounts into the environment, and officials say that the plant will not reopen for at least 18 months.

According to a preliminary report released on 24 April by a DOE-appointed Accident Investigation Board, the root cause of the accident lies with the department’s field office and Nuclear Waste Partnership, the contractor that operates the site, both in Carlsbad. They failed to identify radiological risks and make plans to control them, the report’s authors said. They added that maintenance of safety systems was neglected, and that DOE oversight was “ineffective”………

Ed Lyman, a nuclear expert with the Union of Concerned Scientists in Washington DC, says that he strongly supports exploring the storage of down-blended weapons-grade plutonium at WIPP. Such waste generates much less heat than does spent fuel, he adds. But he rejects storing spent fuel at WIPP, as its likely impacts on the surrounding salt “would be inviting trouble”.

The DOE Field Office in Carlsbad and the Nuclear Waste Partnership had not responded to Naturewhen this article went to press.

Several scientists say that whatever the test results or arguments, the storage of high-level waste at WIPP should be ruled out because of the nature of the site. The area is rich in oil, gas and minerals, and oil and gas wells hug the 41-square-kilometre area. Hydraulic fracturing — fracking — of gas is also carried out nearby. This poses the risk that the WIPP repository could be disturbed by future drilling and mining, for example, by the puncture of the high-pressure brine reservoirs beneath WIPP.

There is no way that the authorities would ever approve such a site for storing high-level waste, says Chaturvedi. http://www.nature.com/news/call-for-better-oversight-of-nuclear-waste-storage-1.15211