The European Accident Code EAC-2 and its Coupling Algorithm between Fuel and Coolant Channel

WE GIVE A SHORT OVERVIEW ON THE DEVELOPMENT OF THE EAC-2 CODE WITH EMPHASIS ON THE COUPLING MECHANISM BETWEEN THE FUEL BEHAVIOUR MODULE TRANSURANUS AND THE THERMOHYDRAULICS MODULES WHICH CAN BE EITHER CFEM OR BLOW3A. THESE MODULES WILL ALSO BE SHORTLY DESCRIBED. SOME NUMERICAL RESULTS ARE GIVEN: THEY ARE RECALCULATIONS OF AN UNPROTECTED LOF ACCIDENT WHICH WAS EARLIER ANALYSED IN THE FRAME OF A COMPARATIVE EXERCISE PERFORMED DURING THE FIRST HALF OF THE 80S ANS ORGANISED BY THE CEC.NA-NOT AVAILABL

EAC - European Accident Code

ONE ASPECT OF FAST REACTOR SAFETY ANALYSIS CONSISTS OF CALCULATING THE STRONGLY COUPLED SYSTEM OF PHYSICAL PHENOMENA WHICH CONTRIBUTE TO THE REACTIVITY BALANCE IN HYPOTHETICAL WHOLE-CORE ACCIDENTS: THESE PHENOMENA ARE NEUTRONICS, FUEL BEHAVIOUR AND HEAT TRANSFER TOGETHER WITH COOLANT THERMO-HYDRAULICS IN SINGLE- AND TWO-PHASE FLOW. TEMPERATURE VARIATIONS IN FUEL, COOLANT AND NEIGHBOURING STRUCTURES INDUCE, IN FACT,THERMAL REACTIVITY FEEDBACKS WHICH ARE ADDED UP AND PUT IN THE NEUTRONICS CALCULATION TO PREDICT THE NEUTRON FLUX AND THE SUBSEQUENT HEAT GENERATION IN THE REACTOR. AT THIS POINT A WHOLE-CORE ANALYSIS CODE IS NECESSARY TO EXAMINE FOR ANY HYPOTHETICAL TRANSIENT WHETHER THE VARIOUS FEEDBACKS RESULT EFFECTIVELY IN A NEGATIVE BALANCE, WHICH IS THE BASIC CONDITION TO ENSURE STABILITY AND SAFETY. THE EUROPEAN ACCIDENT CODE (EAC), DEVELOPED AT THE JOINT RESEARCH CENTRE OF THE CEC AT ISPRA (ITALY), FULFILS THIS OBJECTIVE. IT IS A MODULAR INFORMATICS STRUCTURE (QUASI 2-D MULTICHANNEL APPROACH) AIMED AT COLLECTING STAND-ALONE COMPUTER CODES OF NEUTRONICS, FUEL PIN MECHANICS AND HYDRODYNAMICS DEVELOPED BOTH IN NATIONAL LABORATORIES AND JRC. EAC MAKES THESE MODULES INTERACT WITH EACH OTHER AND PRODUCES RESULTS FOR THESE HYPOTHETICAL ACCIDENTS IN TERMS OF CORE DAMAGE AND TOTAL ENERGY RELEASE.NA-NOT AVAILABL

Comparative Analysis of a Hypothetical Loss-of-Flow Accident in an Irradiated LMFBR Core Using Different Computer Models for a Common Benchmark Problem.

THIS REPORT SUMMARIZES THE RESULTS OF AN INTERNATIONAL EXERCISE TO COMPARE WHOLE-CORE ACCIDENT CALCULATIONS OF THE INITIATION PHASE OF AN UNPROTECTED LOF ACCIDENT IN A LARGE IRRADIATED LMFBR.NA-NOT AVAILABL