The new version of the criticality safety guide sheets collection

The purpose of 'The criticality safety guide sheets' is to gather useful elements in order to get sufficient knowledge to lead a criticality safety analysis for a nuclear installation containing fissile material. The first version of this guide was published in 2001 for the IQC/QCE (Qualified Criticality Engineers) of the French CEA. It was composed of 27 sheets, each of them dealing with a specific topic such as bounding fissile medium definition, criticality control by limitation of the fissile material mass and neutron reflection. This paper presents the new version of these criticality safety guide sheets, published in 2018. This new version is an enhancement of the former one and includes new elements, in particular sheets dealing with: - principles of a criticality safety analysis, - basics of criticality safety calculations, - usual pitfalls in criticality safety. Many new elements have also been included in order to update the guide: - the new French criticality safety resolution, - updated results of criticality calculations, performed with the CRISTAL V2 criticality safety package, - many application examples... The new criticality safety guide sheets are now provided during the training sessions for the new IQC/QCE organized by the INSTN (National Institute for Nuclear Science and Technology). Furthermore, this new version is now available to all in French, including outside the CEA. Some of the sheets are currently being translated into English and examples will be provided. (authors)