Building on the NEA BFBT and PSBT benchmarks, McMaster University, in collaboration with North Carolina State University, launched a CANDU thermal-hydraulic benchmark under the WPRS Expert Group on Uncertainty Analysis in Modelling (EGUAM). The CANDU Owners Group (COG) provided full-scale experimental data for a 28-element CANDU fuel assembly including pressure drop and detailed pin temperatures for single-phase and boiling conditions.

Objectives

The purpose of the benchmark is to:

• provide data for validation of numerical models that predict single and two-phase pressure drop;
• provide data over a wide range of geometrical and operating conditions for validation of single and two-phase heat transfer models;
• provide critical heat flux (CHF) data over a wide range of flows, pressures and temperatures and under full-scale reactor conditions for code testing and model development. Of particular importance are the tests where aged reactor conditions are represented and hence the geometry deviates from nominal conditions;
• provide novel “dry patch” mapping data wherein the post-CHF characteristics like dry-area fraction and post-dryout temperatures can be compared to code predictions.

Reference systems and scenarios

A unique aspect of these data is the traversing thermocouples which provide axial and azimuthal sheath temperatures along every fuel element for both pre= and post-CHF conditions. A wide range of test conditions (inlet pressure, mass flows and inlet temperatures) will be provided to participants along with the temperature scans, CHF location and power, and post-dryout sheath temperatures. Similar to the NUPEC Boiling Water Reactor (BWR) Full-size Fine-mesh Bundle Tests (BFBT)  and NUPEC Pressurised Water Reactor (PWR) Subchannel and Bundle Tests (PSBT)  benchmarks, the complete set of data will be made available to participants after completion of the benchmark.

Exercises

Phase I: Pre-CHF Benchmark

• Exercise 1: Single and two-phase pressure drop benchmark
• Exercise 2: Single-phase heat transfer benchmark
• Exercise 3: Two-phase heat transfer benchmark

Phase II: CHF Benchmark

• Exercise 1: Steady-state CHF benchmark under nominal geometrical conditions
• Exercise 2: Steady-state CHF benchmark under aged channel conditions
• Exercise 3: Transient heat transfer and CHF benchmark
• Exercise 4: Post-dryout sheath temperature benchmark

Members

Members' working area (password protected | reminder)

Contacts

NEA: O. Buss

McMaster University Co-ordinator: D.R. Novog