The first draft of a safety report that explains risk assessments for nuclear power stations with multiple reactors – known as multi-unit probabilistic safety assessments – is expected to be released by the end of 2020, the International Atomic Energy Agency said.The assessments are used to help improve plant safety in case of a multi-unit accident and are required by regulators in certain countries. However, they are challenging to conduct, the IAEA said.The IAEA has now developed and tested a methodology to ease the process by providing step-by-step guidance to experts on conducting an assessment.