The overall objective of OECD programme SERENA (Steam Explosion Resolution for Nuclear Applications) is to consolidate understanding on FCI phenomenology and assess method(s) for reliable estimate of the magnitude of loadings for realistic reactor conditions, in order to bring understanding and predictability of FCI energetics to desirable levels for risk management. The programme is divided into two phases. Phase 1, purely analytical, made a status of the predictive capabilities of the FCI codes through comparative calculations of most relevant existing experiments and reactor cases, with the scope of identifying those areas where large uncertainties/discrepancies still subsist and are important for predicting loads in reactors. Calculations were performed by using ESPROSE-m, IDEMO, IFCI, IKEMIX, JASMINE, MATTINA, MC3D, PM-ALPHA, TEXAS-V, TRACER and VESUVIUS codes. If required, a second phase may be undertaken, with the scope of carrying out the confirmatory analytical and experimental research possibly needed to reach the objective. Phase 1 showed that all the codes were able to calculate reactors situations. The way they have been used, the calculated in-vessel loads were found far below the capacity of a typical intact vessel and above the capacity of a typical cavity. Confidence in these conclusions are challenged by the large scatter of the results, and by the uncertainties related to the description of the flow patterns in the pre-mixing phase, in particular void fraction evolution, and to the missing physical justification of the reduced energetics observed with corium melts. Addressing these issues is required to confirm these conclusions for in- vessel steam explosion and quantify the safety margins for ex-vessel steam explosion. This is proposed as a Phase 2 of SERENA with the support of KROTOS and TROI experimental facilities.