It's not a new debate, but still a controversial one: calls by conservative politicans to rethink energy policy and review Germany's commitment to phasing out nuclear power plants, and putting the focus on renewable energy sources such as solar and wind power. They say that's not enough to meet Germany's urgent - and strategic - energy needs, and anyway, you need multiple options at a time of soaring gas and oil prices. Critics say that's opportunistic and short-sighted without offering clear answers to reactor safety and the continuing, unresolved issue of nuclear waste and its impact on the environment. That doesn't impress German nuclear researchers though, working on technology to replace outdated plants: technology that will then be used abroad.