3D Space-Time Analysis of Anticipated Transient Without Scram in CHTR with Fuel Temperature Feedback

The compact high temperature reactor (CHTR) is being developed as technology demonstrator and critical facility for Indian high temperature reactor program. Physics design of envisaged core of Th-U233-based TRISO-coated particle-fueled CHTR is in advance stage, and various core configurations have been proposed. Reactor core operation at high temperature necessitates sophisticated safety and anticipated transient analyses including postulated loss of regulation accident, LOCA as well as intentional power setback transient in CHTR. An efficient IQS module in 3D space-time analysis code ARCH with adiabatic Doppler feedback capability has been developed for reactor transient simulation. For temperature feedbacks in reactivity transients in CHTR, 1D radial heat conduction in multichannel-based TH module has also been incorporated with IQS module in code ARCH. The coolant hydraulics in incorporated TH module of ARCH-IQS is limited to given mass flow rate and inlet temperature in every channel. The capability of fuel temperature feedback in the code has been checked with AER benchmark analysis. Some of the results of ARCH-IQS code for benchmark (AER-DYN-002) with Doppler feedback are presented in this paper. 3D space-time analyses of anticipated transient without scram (ATWS) cases of CHTR have been carried out with only fuel temperature feedback, and results are also discussed in this paper.