A New Methodology to Obtain the 1D Cross-Sections for TRAC-BF1 Code: Application to Peach Bottom NPP

In TRAC-BF1 the cross-sections are specified in the input deck in a polynomial form. Therefore, it is necessary to obtain the coefficients of this polynomial expansion. One of the methods proposed in the literature is the KINPAR methodology developed in the UPV. This methodology uses the results from different perturbations of the original state to obtain the coefficients of the polynomial expansion. The simulations are performed using the SIMULATE3 code. In this work, a new methodology called SIMTAB-1D to obtain the cross-sections sets in 1D is presented. The first step consists of the application of the SIMTAB methodology, developed in the UPV, to obtain the 3D cross-sections sets from CASMO4/SIMULATE3. These 3D cross-sections sets are collapsed to 1D, using as a weighting factor, the 3D thermal and rapid neutron fluxes obtained from SIMULATE3. This new methodology will be applied to the simulation of the turbine trip transient in Peach Bottom NPP using the TRAC-BF1 code. The results of the steady state in TRAC-BF1 using the KINPA R methodology and the new methodology are compared with the reference SIMULATE3 results.