Radiological Impact Assessment

Context The SMR-LFR project at SCK CEN aims at building and operating LEANDREA, developed as both a SMR-LFR technology demonstrator and a test facility for materials and fuels specific to fast reactors, and will support research into applications beyond electricity production. Lead-cooled fast reactors rely on an inherent-safety technology, in particular basing on the lead high thermal inertia, its fission products retention property, negative reactivity feedbacks and absence of pressurization in normal operation.

Because of its inherent properties, the internal and external hazards can become main initiators of design basis accidents. In particular, a fire can enhance the evaporation of radiotoxic volatiles from the radioactive sources in contact with the hot-temperature atmosphere generated by the fire.

Incidental/accidental radiological impact of LEANDREA is estimated with Radspot, a computer code that calculates the off-site radiological consequences RSO1, RSO2 or RSO3 following a ground release or a stack release according to the indications provided in the “Guidance on the application of conservative and less conservative approaches for the analysis of radiological consequences”, issued by Bel V in 2017. The aim of thesis work is improving the modelling capabilities of Radspot in fire scenarios, and evaluating the reduction in radiological impact by taking into account those models.

Thesis Objectives In this thesis, the student will focus on both radiological stack and ground releases in a fire scenario. In particular, she/he will:

Make a literature research and implement robust and licensable models to of the radioactive plume at the emission point in Radspot Develop a compartment model to provide realistic source term (activity rate in function of time) to Radspot, as input for the radiological impact assessment Verify the simulation results against simple verification problems Benchmark the results with similar computer codes Candidate Profile The ideal candidate should possess several of the following skills.

Familiarity with the safety of nuclear reactors, in particular with radiological impact phenomenology Basic programming in Python or similar scientific computing codes Basic programming in C++ is a plus Familiarity with the Linux command line and HPC systems The minimum diploma level of the candidate needs to be Master of sciences The candidate needs to have a background in Nuclear Engineering Estimated duration 6 months Expert group Reactor Physics & Safety