The Swedish National Council for Nuclear Waste has organised a conference on the future of nuclear waste disposal in the wake of new evidence that casts doubt on the safety of current disposal methods. Research on copper artefacts found on the Vasa, the 17th century ship recovered from Stockholm’s harbour in 1961, has shown that copper decays under water – a finding which challenges the traditional view about copper’s durability. Copper has traditionally been used to store radioactive waste, but this may change as a result of these findings.