report

Belgian stress tests action plan ‐ 2012‐12‐14No Topic Source Recommendations, Requirements from other national reviews Action : Family ‐ subfamily ‐ sub‐subfamilyActions to beimplementedComment47Emergencypreparedness andresponseNational regulatoryinspection∙ the BK procedures should provide quantitative criteria for selected keyparameters to quickly arbitrate between the evacuation of the residual heatand the isolation of a leak in recirculation lines;Severe Accidents management ‐ Review SAMGprocedures ‐ Coherence severe accidents proceduresbetween Doel and Tihange521, 522§ 7.2.5 of national stresstests report48Emergencypreparedness andresponseNational regulatoryinspection∙ a decision support tool should be added to the BK procedures to arbitratebetween injecting into the primary circuit and spraying inside the containmentbuilding.Severe Accidents management ‐ Review SAMGprocedures ‐ Coherence severe accidents proceduresbetween Doel and Tihange521, 522§ 7.2.5 of national stresstests report49Emergencypreparedness andresponseNational regulatoryinspectionAs much as possible, the licensee should consider to increase the consistencybetween the Tihange NPP and the Doel NPP with respect to the emergencytraining and refresher training programs (different in duration and frequency).Emergency management ‐ Requirements ‐Harmonization of sites training programs516§ 7.2.5 of national stresstests report50Emergencypreparedness andresponseNational regulatoryinspectionFor the Doel NPP, the licensee states that the probability of a steam explosionwhen corium falls out of the reactor vessel into a flooded reactor pit is very lowand can thus be neglected, based on various experiments carried out as part ofinternational research programs that were unable to create this phenomenon.For the Tihange NPP (where the reactor pit is not flooded prior to the reactor Severe Accidents management ‐ RB protection ‐vessel breach), the licensee states that a feasibility study of a system allowing Research &Development for severe accidentswater injection into the reactor pit will be launched.However, the licensee should follow‐up the ongoing steam explosionexperiments closely. If needed, the current strategies for flooding of the reactorpit before the rupture of the reactor vessel should be adapted.183, 394, 513, 518§ 7.2.5 of national stresstests report51Emergencypreparedness andresponseNational regulatoryinspectionThe licensee should also assess the need of fitting new devices that would beuseful for severe accident management (pH measurement in the sumps,temperature measurement at the bottom of the reactor vessel to monitor apotential core melt). The associated hardware modifications to improve thoseaspects should be sought where appropriate.Severe Accidents management ‐ RB protection ‐Reactor pit injection166, 167, 168§ 7.2.5 of national stresstests report52Emergencypreparedness andresponseNational regulatoryinspectionThe licensee should identify the effective means to control the pH inside thecontainment building after a severe accident. This requirement applies in theearly stages of the accident, and also during the long term phase.For the management of the long term phase of a severe accident, the licenseeshould take into consideration the impact of other severe accidentmanagement actions on the possibility of refilling the NaOH tank and thepossibility for non‐NaOH injection related measures to influence the sumpwater pH in the alkaline direction.Severe Accidents management ‐ Radiological release ‐pH reactor control620§ 7.2.5 of national stresstests reportAdditional topics8/9