While the nuclear industry is promoting a new generation of ‘passively safe’ reactors, closer inspection reveals that improved safety features fall a long way short of the sweeping claims being made.

So-called Generation III reactors feature standardised designs offering advantages over most of the world’s currently operating (Generation II) reactors. These include ‘passive’ safety features which depend only on physical phenomena such as convection, gravity or resistance to high temperatures, not on functioning of engineered components.

The only operating Generation III reactors are four advanced boiling water reactors in Japan. Other Generation III reactors are under construction including the reactor in Finland which is well over budget and behind schedule. Licensing of some other Generation III reactor designs − in particular the AP1000 and EPR designs − has been protracted and has yet to be completed.

Hirsch et al. (2005) summarise: “All in all, ‘Generation III’ appears as a heterogeneous collection of different reactor concepts. Some are barely evolved from the current Generation II, with modifications aiming primarily at better economics, yet bearing the label of being safer than current reactors in the hope of improving public acceptance. Others are mostly theoretical concepts so far, with a mixture of innovative and conventional features, which are being used to underpin the promise of a safe and bright nuclear future – while also not forgetting about simplification and cost-cutting.”

A director of a US research laboratory has noted that “fabrication, construction, operation, and maintenance of new reactors will face a steep learning curve: advanced technologies will have a heightened risk of accidents and mistakes.” (Quoted in Sovacool, 2010.) Another nuclear industry insider has quipped: “We know that the paper-moderated, ink-cooled reactor is the safest of all. All kinds of unexpected problems may occur after a project has been launched.” (Quoted in Hirsch et al., 2005.)

More radical ‘Generation 4’ reactor concepts are a long way from deployment. The Generation 4 International Forum website states that “commercial deployment of Gen-IV reactors is not foreseen before 2030 at the earliest, and all current activities involving Gen-IV designs are at the level of R&D.” The World Nuclear Association (2009) is also downbeat, noting that “progress is seen as slow, and several potential designs have been undergoing evaluation on paper for many years.”

Regarding Generation IV concepts, Hirsch et al. (2005) state: “A closer look at the technical concepts shows that many safety problems are still completely unresolved. Safety improvements in one respect sometimes create new safety problems. And even the Generation IV strategists themselves do not expect significant improvements regarding proliferation resistance. But even real technical improvements that might be feasible in principle are only implemented if their costs are not too high. There is an enormous discrepancy between the catch-words used to describe Generation IV for the media, politicians and the public, and the actual basic driving force behind the initiative, which is economic competitiveness.”

(For further discussion on safety aspects of Generation III and IV concepts, see Schaper et al., 1999; Froggatt, 2006; Hirsch et al., 2005; World Nuclear Association, 2010.)