Montreal Nuclear Services
Develop reactor physics model of Gentilly-2 for use in safety analyses.
In order to comply with regulatory requirements from the Canadian Nuclear Safety Commission (CNSC), Hydro-Québec needed to update their reactor model to full 2-group models to be used in detailed safety analyses, performed in support to refurbishment. The Gentilly-2 physics model evolved since 1982 to an SCM model, using WIMS-AECL 2 group properties. However a large number of properties, mostly for structural material, were still based on commissioning models. The work consisted of identifying dimensions andisotopic compositions of all structural materials and reactivity devices, to model them in 3D within DRAGON, and to integrate them into RFSP core model. In total, eight core models have been developed to represent the reactor life time (fresh core, plutonium peak core, uncrept time-average core and 20-year crept time-average core), and the adjuster rod design (stainless steel or cobalt adjusters). The objectives of the work were also to determine the reactivity coefficients for fuel temperature, coolant density and coolant temperature to be used in thermohydraulics code for safety analyses (e.g. CATHENA).
The work was contracted by Hydro-Québec to AECL (Atomic Energy of Canada Ltd). Dr. Elisabeth Varin was the technical lead and she supervised work performed in Montréal and in Mississauga.
NOTE: This work was performed / lead by MNS personnel during their previous employment
DRAGON models for cobalt adjuster rods (one to four Cobalt pins), and for structural materials,
core model for fresh core, including depleted bundles, RFSP core model
for crept time-average conditions, including 35 crept fuel models
report including description of all structural material and reactivity
mechanisms, creep information after 20 years, SCM fuel table description
for uncrept, crept and fresh fuel bundles (natural and depleted uranium
composition), RFSP models showing channel power distributions, and
kinetics parameters for each core model
coefficients for each core model for fuel temperature, coolant density
and coolant temperature to be used in trip coverage analysis