Full-scale modeling GEN-IV fuels (PhD)

Since the beginning of the MYRRHA project (1997), the Belgian nuclear research Centre SCK•CEN gives great attention to the problems of Minor Actinide (MA) and Long Living Fission Products (LLFP) transmutation and to the modeling of the dedicated transmutation fuels. New models for prognosis of thermo-mechanical properties of these fuels and new mechanistic codes capable to deal with MA-containing oxide fuels (homogeneous and heterogeneous) and inert matrix fuels (IMF) are being developed at SCK•CEN. These models and codes have already partially been used in the EURATOM FP5 FUTURE program for the pre-design of fuel pins of the accelerator-driven transmuter ADT-800 and for simulation of the behaviour of the fuel rods with the solid solution fuels (Am,Pu,U)O_2-x, (Am,Pu,Th)O_2-x, (Am,Pu,Zr,Y)O_2-x and with the composite fuel (Am,Pu)O_2-x + MgO during their long term operation in ADT-800. This work is continuing (but with other fuels – (Cm,Am,Pu) O_2-x+Mo and (Cm,Am,Pu)O_2-x + MgO) in the framework of FP6 IP EUROTRANS, ELSY and LWR-DEPUTY projects.

The development of models for fuels dedicated  to MA and LLFP transmutation is also continuing in the framework of FP6 IP EUROTRANS and in own SCK·CEN MYRRHA projects. In the framework of IP EUROTRANS it is planned to benchmark some of the developed models on the results of the few available experiments with IMF and to apply them for simulation and post-irradiation examination of the results of the BODEX irradiation experiment. The results of two other irradiation experiments with MA fuel being performed in IP EUROTRANS, HELIOS and FUTURIX-FTA, will be available after completing the IP EUROTRANS, and the PIE of both is proposed to be performed in FP7 FAIRFUELS project. Consequently, it is logical to envisage the analysis of the results of these experiments and PIE and further refinement and benchmark of the models of the dedicated fuels in WP3 ("Modelling in support of PIE") of the project.

Thus, the main objective of the PhD study will be the development of the models for prognosis of main thermal and mechanical properties of the IMF dedicated to MA transmutation, and their long term behavior in a reactor-transmuter. They should allow:

·         to evaluate degree of changes in original inert matrix compounds and impact of changes on thermal and mechanical performance of fuel pins in typical for ETD irradiation conditions;

·         to assess post irradiation behavior of transmuted targets (long term storage) in terms of heat and gas generation and release, structure stability and integrity.