2017 | AFC ACCOMPLISHMENTS 83 This project evaluates the performance of advanced fuel/ ATF options and identifies whether the options have at least equivalent performance to the present UO2-Zr fuel- cladding system under nominal conditions and improved performance in accident scenarios. feedback in the PARCS point kinetics model differs fromTRACE in the way core parameters are averaged: square power-weighted average forTRACE, and adjoint- and fission cross-section- weighted average for PARCS. Results indicate the two codes compare favorably for the initial phase of the transient when the reactor power is increasing and the final phase when the reactor approaches a higher steady power.TRACE appears to predict a higher and broader power peak than PARCS and is thus more conservative. Additional loss-of-coolant accidents (LOCA) have been analyzed to eval- uate the impact of burnup-dependent fuel pellet thermal conductivity on the peak cladding temperature. Results of a small-break LOCA analysis indicate that the increased stored energy due to the lowering of the thermal conduc- tivity has little impact on the peak clad temperature (PCT).According to the transient results the PCT occurs some 80 s after the initiation of the accident and by then most of the stored energy has already been released from the fuel. It is anticipated that the thermal conductivity degradation (TCD) effect due to burnup will be more significant for faster transients such as a large-break LOCA. An effort was initiated to benchmark results produced by theTRACE 3-loop PWR plant model against design basis accidents presented in the Safety Analysis Report (SAR) for a typical 3-loop plant.The comparison provides guidance on the modeling of the emergency core cooling systems (ECCS), especially in regard to their performance in terms of initiation and duration of the injection and the rate of injection.