23 May (NucNet): Nuclear plant operators and their regulators should upgrade and protect nuclear plant security infrastructure and systems to cope with extreme external events and severe accidents, a study by the US National Academy of Sciences (NAS) says.
The study, phase two of a study carried out at the request of US Congress on lessons learned from the March 2011 Fukushima-Daiichi accident, focuses on security and safety at nuclear stations.
The NAS committee that carried out the study said operators and regulators need to ensure that there is adequate separation of plant safety and security systems so that security systems can continue to function independently if safety systems are damaged. “In particular, security systems need to have independent, redundant, and protected power sources,” the committee said.
The committee also said nuclear operators and regulators need to train security personnel in implementing approaches for “reconstituting security infrastructure and systems and staffing during and following external events and severe accidents”.
The committee said it sees an opportunity for the nuclear industry to expand its “Flex” initiative to include critical security-related equipment such as access control, intrusion detection and assessment, communications, and portable-lighting equipment.
This equipment would need to be sufficiently standardised so that it could be used across the US nuclear fleet and protected against extreme external events, severe accidents, and sabotage.
Security personnel at US nuclear stations would need to be trained on the use of this equipment if it were different from existing equipment at their plants, the committee said.
The US nuclear industry’s Flex initiative addressed the major problem encountered at Fukushima-Daiichi – the loss of water and power to maintain effective reactor cooling – by stationing additional layers of backup safety equipment in well-protected locations at all plant sites. The equipment ranges from diesel-driven pumps and electric generators to ventilation fans, battery packs, hoses, cables and satellite communication gear, the Washington-based Nuclear Energy Institute said.
Phase one of the NAS study, issued in 2014, focused on the causes of the Fukushima-Daiichi accident and safety-related lessons learned for improving nuclear plant systems, operations, and regulations exclusive of spent fuel storage.
The 2014 study said the overarching lesson learned from Fukushima-Daiichi was that nuclear plant licensees and their regulators must “seek out and act on new information” about hazards with the potential to affect the safety of nuclear stations. It called on the nuclear industry and organisations with emergency management responsibilities to “assess their preparedness” for severe nuclear accidents associated with offsite regional-scale disasters.
The 2016 study is online: http://bit.ly/1XK43ix
