Stress tests at Russian nuclear power plants have confirmed that their designs ensure protection against external natural and man-induced impacts, according to a report from the Russian nuclear regulatory Rostechnadzor.

Stress tests for individual nuclear power plants, in particular for units with VVER-1000 reactors, demonstrated that there are ‘strength margins with regard to seismic impacts that exceed the impacts subject to consideration in the NPP design bases,’ news agency ITAR-TASS reported.

Rafael Arutyunyan, first deputy director of the Nuclear Safety Institute of RAS, said in an interview with ITAR-TASS that upgrading nuclear reactors ‘is a nearly endless process,’ because it is carried out not for an economic benefit but for safety enhancement.

After the stress tests Rosenergoatom plans to implement a set of measures to strengthen safety systems, in particular hydrogen protection systems, he said.

Arutyunyan also noted that it is necessary to upgrade not only old but also modern NPPs, giving an example that the passive protection of the AES-2006 design has now been increased from 24 hours to 72 hours.