I-NERI QUARTERLY TECHNICAL PROGRESS REPORT - JANUARY 1 - MARCH 31, 2005

Oh, Chang

Idaho National Laboratory

关键词: Diffusion;    Chemical Reactions;    Power Distribution;    Surface Area;    Transients;   

DOI  :  10.2172/911734
RP-ID  :  INL/EXT-05-00206
RP-ID  :  DE-AC07-99ID-13727
RP-ID  :  911734

美国|英语

来源: UNT Digital Library

【 摘 要 】

The objective of this Korean/United States/laboratory/university collaboration is to develop new advanced computational methods for safety analysis codes for very-high-temperature gas-cooled reactors (VHTGRs) and numerical and experimental validation of these computer codes. The research will improve two well-respected light water reactor transient response codes (RELAP5/ATHENA and MELCOR) in the modeling of molecular diffusion and chemical equilibrium, and to validate these codes against the VHTGR accident data, i.e., air ingress and others from the literature. The VHTGR is intrinsically safe, has a proliferation-resistant fuel cycle, and many advantages relative to light water reactors (LWRs). This study consists of five tasks for FY-03: (1) development of computational methods for the VHTGR, (2) theoretical modification of aforementioned computer codes for molecular diffusion (RELAP5/ATHENA) and modeling CO and CO{sub 2} equilibrium (MELCOR), (3) development of a state-of-the-art methodology for VHTGR neutronic analysis and calculation of accurate power distributions and decay heat deposition rates, (4) reactor cavity cooling system experiment, and (5) graphite oxidation experiment. First quarter of Year 3: (A) Prof. NO and Kim continued Task 1. We first performed the chemical reaction test for the VELUNA pebble oxidation experiment and then the analysis of the air ingress accident for PBMR 268MWt. In the GAMMA analysis, significant rise in pebble temperature was observed at the bottom of the core due to graphite oxidation. Since the air ingress process depends on the vault conditions, further analysis coupled with more detailed vault or containment modeling would be necessary as a future study. (B) Prof. Park continued Task 2. The experiments for SNU-RCCS were continued to provide the experimental data for the validation of the thermal hydraulic code being developed at KAIST and to evaluate the performance of the system using the experiments and system analysis codes. The three categories of experiments were performed in the facility; (1) upper pool cooling trip test, (2) LOFC experiment, (3) emissivity measurement experiment. (C) Prof. NO continued Task 3. (Prof NO) The experimental work of air ingress is going on without any concern: Geometry and size effect test has been completed. The conversion factor for internal surface area was obtained through this experiment. Burn-off test was performed and the uniformity of internal reaction was confirmed. (D) INEEL engineers continued to extend the diffusion model for multiple chemical species and made some calculations. (E) Prof. Lee and Martin at University of Michigan continued to analyze the effect of the stochastic fuel on the neutronic analysis and have initiated fuel depletion calculations for the VHTGR core. Progress during the past quarter includes: Further analysis of stochastic fuel geometry; Preliminary Monte Carlo depletion of full-core VHTGR; and Installation of MCNP5 on Unix cluster.