Researchers are proposing an improved barrier design to enhance the safety of light water reactors (LWRs) and bolster the contribution of nuclear power to global energy supplies. The cost-effective system is designed to prevent loss of coolant accidents by application of "As Low As Reasonably Achievable" principles.

Five layers of safety protection address fuel and cladding weakness, the primary circuit pressure boundary, Safety barrier schematic. Source: F. D’Auria et al.emergency core cooling systems, confinement structures and a risk-informed technological barrier. The concept incorporates recent research findings concerning nuclear fuel structural weakness and an elaborate extended safety margin detection capability, which allows for emergency shutdown of a reactor following low and very low probability events. It also provides advance information to operators about the actions needed to prevent or mitigate possible damage.

The researchers propose the recruitment of an emergency rescue team, consisting of a group of highly trained personnel who will be in possession of suitable machinery and equipment, as well as access to each nuclear reactor installed within an assigned geographic region. The team will be able to reach any of the sites within an hour or execute a remote shutdown of the reactor.

If available in 1979, the extended safety margin detectors would have triggered the emergency shutdown of the Three Mile Island station well before the failure event. An intervention from the emergency rescue team as a remotely controlled shutdown would likely have prevented the 1986 Chernobyl catastrophe. Extended core damage at the Fukushima Units 1 to 3 in 2011 would have also been prevented thanks to the combination of emergency alerts and prompt action by the emergency rescue team.

Researchers from the University of Pisa (Italy), the University of Zagreb (Croatia) and the Global Research for Safety (Germany) contributed to this study, which is published in Nuclear Energy and Technology.