The development of high-fidelity full-core modeling capabilities for LWRs is the stated goal of several projects such as CASL (Consortium for Advanced Simulation of LWRs). In this benchmark, the work performed by CASL in their VERA Core Physics Benchmark Progression Problems is extended into a Nuclear Energy Agency code-independent benchmark to encourage Verification and Validation (V&V) of traditional and novel high-fidelity Modelling and Simulation (M&S) from multiple participants.
The benchmark specifications originate from a selected set of CASL benchmark problems based on data provided by the Tennessee Valley Authority (TVA) and other references available in the public domain. It introduces a benchmark which provides detailed specifications of the WBN1 core operations measured by TVA. The data are provided for Watts Bar Unit 1 Cycle 1 (WBN1C1) and Cycle 2 (WBN1C2). Five exercises cover the key states of WBN1C1 and WBN1C2. The exercises span the start-up Zero Power Physics Tests (ZZPT), Hot Full Power (HFP) Beginning of Cycle (BOC) Physical Reactor, depletion of WBN1C1, fuel shuffle and decay for Cycle 2 BOC ZPPT, and WBN1C2 depletion.
In order to support the development of the VERA for multi-physics applications, CASL developed a set of benchmark progression problems ranging from simple two-dimensional pin cells to three-dimensional multi-physics reactor core problems. There are five exercises within the benchmark:
Exercise 1: Validation of stand–alone 3-D neutronics model at HZP conditions
This exercise aims to calculate the required parameters of the WBN1C1 ZPPT BOC startup. The loading pattern of this exercise is provided, the fuel assemblies in this exercise are at the beginning-of-life (BOL) conditions and the reactor is at Hot Zero Power (HZP) isothermal conditions. The initial criticality was achieved by inserting bank D while all other banks were fully withdrawn.
Exercise 2: Verification of multi-physics steady state model for HFP conditions
This exercise aims model WBN1C1 at nominal conditions with the loading pattern and material properties described in the benchmark. In this exercise, bank D is partially inserted while all the other RCCA banks are withdrawn. The prediction of the HFP distribution requires the calculation of the Xenon equilibrium across all the fuel rods in the reactor core. No measured data were provided by TVA for this exercise, therefore the reference results are taken from the calculated MC21/CTD simulation, published in report CASL-U-2015-1010-001.
Exercise 3: Validation of multi-physics cycle1 depletion model for Cycle 1
The exercise aims to predict the depletion of the WBN1C1 fuel, fission product build-up and decay and material activation within core structures. The averaged operating power history is provided in the benchmark specifications.
Exercise 4: Validation of fuel shuffle and decay for Cycle 2 BOC ZPPT
This exercise focuses on the analysis of the WBN1 refueling and the fuel reactivity at HZP conditions in Cycle 2. The loading pattern of this exercise is described in the specifications. The length of the refueling process between Cycle 1 and Cycle 2 is assumed to be 30 days and isotopic components, including those for boron, are provided.
Exercise 5: Validation of multi-physics cycle1 depletion model for Cycle 2
The exercise aims to predict the depletion of the WBN1C2 fuel, fission product build-up and decay and material activation within core structures. The loading pattern of this exercise is described in the specifications.
Details, including specifications and results templates can be found in the working area. To access the working area, please fill out the conditions form and e-mail it to firstname.lastname@example.org.
The Benchmark for Uncertainty Analysis in Best-Estimate Modelling (UAM) for Design, Operation and Safety Analysis of Light Water Reactors (LWRs) is an international high-visibility benchmark for uncertainty analysis in best-estimate coupled code calculations for design, operation, and safety analysis of LWRs. The annual workshops are attended by many experts in industry, research institutes, national laboratories, academia, and government agencies.
The goal of the Benchmark for Uncertainty Analysis in Best-Estimate Modelling for Design, Operation and Safety Analysis of Light Water Reactors (LWR-UAM) is to determine the uncertainty in light water reactor (LWR) systems and processes in all stages of calculations. It is estimated through a simulation process of ten exercises in three phases provided by the benchmarking framework.
This benchmark was a continuation of the V1000CT activities and defined a coupled code problem for further validation of thermal-hydraulics system codes for application with Russian-designed VVER-1000 reactors based on actual plant data from the Russian nuclear power plant Kalinin Unit 3 (Kalinin-3)
A number of tests with detail well documented neutronics and thermal-hydraulics measurements data have been performed at the Rostov Unit 2 (Rostov-2) nuclear power plant (NPP). The reactor type is a VVER-1000 with fuel assemblies of type TBC-2M, which enable an 18-month fuel cycle length.
The Subgroup on Uncertainty Analysis in Modelling (UAM) for Design, Operation and Safety Analysis of Sodium-cooled Fast Reactors (SFR-UAM) was formed to check the use of best-estimate codes and data.
The Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) studies the reactor physics, fuel performance, and radiation transport and shielding in present and future nuclear power systems.