You really cannot ask for a better policy than this:
EN261 We will cancel construction of new nuclear stations and nuclear power will not be eligible for government subsidy; the Green Party opposes all nuclear power generation and is particularly opposed to the construction of new nuclear power stations, electricity from which is likely to be significantly more expensive per unit supplied than other low-carbon energy sources, and too slow to deploy to meet our pressing energy needs. Cancellation will avoid the costs and dangers of nuclear energy and waste being passed on to future generations long after any benefits have been exhausted.
EN262 Money earmarked for new nuclear plant research, development and construction will be reallocated to energy efficiency measures and renewable energy infrastructure, but sufficient funding for decommissioning redundant power stations, and for research into the safe storage or disposal of existing radioactive waste stockpiles will be retained.
For the full official energy policy, see Green Party Policy: Energy. (There are links on that page to their other policies.)