The aim of the benchmark is to improve understanding and modelling of pellet-cladding mechanical interaction (PCMI) amongst NEA member organisations. This is achieved by comparing PCMI predictions of different fuel performance codes for a number of cases. Some of these cases are hypothetical cases aiming to facilitate understanding of the effects of code-to-code differences in fuel performance models. The remaining cases are actual irradiations, where code predictions will be compared to measured data. The benchmark is currently restricted to light water reactor (LWR) fuel, but can potentially be extended to other fuel types (in particular CANDU fuel or fast reactor fuel) in the future.

The benchmark is conducted with the oversight of the Expert Group on Reactor Fuel Performance (EGRFP). The aim of the benchmark is to improve understanding and modelling of pellet-cladding mechanical interaction (PCMI) amongst NEA member organisations. This will be achieved by comparing PCMI predictions of different fuel performance codes for a number of cases. Some of these cases are hypothetical cases aiming to facilitate understanding of the effects of code-to-code differences in fuel performance models. The remaining cases are actual irradiations, where code predictions will be compared to measured data. The benchmark is currently restricted to light water reactor (LWR) fuel, but can potentially be extended to other fuel types (in particular CANDU fuel or fast reactor fuel) in the future.

Description of cases

• Case 1: modelling of hypothetical beginning of life (BOL) ramp of pressurised water reactor (PWR) rodlet
• Case 2: modelling of hypothetical BOL ramp of commercial PWR rod
• Cases 3 and 4: modelling and comparison with experimental data provided by Halden Reactor Project (HRP):
• Case 3: BOL ramp of experimental rods with different pellet designs, IFA-118 rig (irradiated in the Halden Boiling Water Reactor (HBWR) from 1969 to 1970)
• Case 4: End of life (EOL) ramp of PWR rodlet IFA-629.4 rod 7

Provisional schedule

The preliminary timescales are below. They reflect the current plan for cases 1 and 2 (but not cases 3 and 4) to be modelled by both EGRFP members and members of the IAEA Fuel Modelling in Accident Conditions (FUMAC) Co-ordinated Research Project.

• February 2015: kick-off meeting as part of the EGRFP meeting (including agreement on conditions for release, collaboration with IAEA, format of predictions to be submitted, interested participants)
• June 2015: benchmark start, after signature of Non-Disclosure Agreement by participants
• December 2015: deadline for submittal of predictions for Cases 1 and 2 (hypothetical cases)
• February 2016: collated Case 1 and 2 results reported by benchmark leader (identity TBD) at EGRFP meeting;
• Mid-2016: benchmark presented and discussed at planned NEA Working Group on Fuel Safety (WGFS) PCI workshop
• December 2016: deadline for submittal of predictions for Cases 3 and 4 (real cases with measured data)
• February 2017: collated Case 3 and 4 results reported by benchmark leader (identity TBD) at EGRFP meeting
• December 2017: benchmark results and discussion written up in NEA report
• February 2018: NEA report endorsed at EGRFP meeting
• June 2018: report issued by NEA

Members' area

PCMI Benchmark (password protected | reminder)

Contact

Michelle.Bales@oecd-nea.org