McMaster University, University Hall Tower and Archway. Photo credit: Matthew Ingram, Uploaded: 12 May 2007, CC BY 2.0.

The 2026 annual Benchmarks Workshops of the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) were hosted by Nuclear Operations & Facilities and the Department of Engineering Physics at McMaster University, and located in Hamilton, ON, Canada.

The event was mainly supported by the Safety Licensing Program of Conexus Nuclear Inc. (formerly CANDU Owners Group), on behalf of its four Canadian domestic funding members (Bruce Power (BP), Canadian Nuclear Laboratories (CNL), New Brunswick Power (NBP), and Ontario Power Generation (OPG)), and three international funding members (Societatea Nationala Nuclearelectrica S.A. (SNN), Romania, Korea Hydro and Nuclear Power Company (KHNP), Korea, and CNNP Nuclear Power Operations Management Company Ltd. (CNNO), China).

From 11 to 15 May 2026, participants of the different WPRS Benchmark Activities met, exchanged results and discussed future activities. The WPRS Benchmarks Workshops addressed benchmarks for neutronics,  thermal-hydraulics, fuel performance, and multi-physics aspects of reactor core simulations in light-water reactors (LWRs), high-temperature gas-cooled reactors (HTGRs), sodium-cooled fast reactors (SFRs), lead-cooled fast reactors (LFRs), and molten-salt reactors (MSRs).

Two topical sessions took place during the workshops:

• Modelling, simulation, verification, validation, and uncertainty quantification of microreactors
• Modelling, simulation, verification, validation, and uncertainty quantification of molten salt reactors

The fourth edition of the NEA International School on Simulation of Nuclear Reactor Systems (SINUS) and the twelfth edition of the CTF User Group Meeting and Training (organised by North Carolina State University, USA) were co-hosted with the Workshops.

The workshops took place at McMaster University, in Hamilton, ON, Canada.

Registered users were given access to a dedicated NEA SharePoint page with detailed agendas and all meeting material.

Here is the high-level agenda:

Local organisers

• David NOVOG, McMaster University, Canada
• Raluca PETRIA, McMaster University, Canada
• Karin STEPHENSON, McMaster Unviersity, Canada
• Wei SHEN, Conexus Nuclear Inc., Canada

Technical programme advisor

• Prof Kostadin IVANOV, North Carolina State University (NCSU), United States

Session chairs

• Dr Agustin ABARCA, NCSU, United States
• Dr Arzu ALPAN, Oak Ridge National Laboratory, United States
• Prof Dr Maria N. AVRAMOVA, NCSU, United States
• Dr Laurent BUIRON, CEA, France
• Dr Roberto DA VIÀ, ENEA, Italy
• Dr Grigorios DELIPEI, NCSU, United States
• Dr Aaron EPINEY, Idaho National Laboratory, United States
• Prof Nuria GARCIA HERRANZ, Universidad Politécnica de Madrid (UPM), Spain
• Prof Alireza HAGHIGHAT,  Virginia Tech, United States
• Dr Jason HOU, NCSU, United States
• Dr Jean-Marie LE CORRE, Westinghouse, Sweden
• Dr Francesco LODI, ENEA, Italy
• Prof Bojan PETROVIC, Georgia Institute of Technology, United States
• Mr Géraud PRULHIÈRE, CEA, France
• Dr Pascal ROUXELIN, NCSU, United States
• Dr Nicolas STAUFF, Argonne National Laboratory, United States
• Dr Claire VAGLIO-GAUDARD, CEA, France
• Prof Xu WU, NCSU, United States
• Prof Xingang ZHAO, University of Tennessee, United States

NEA Secretariat

• Dr Davide MANCUSI, WPRS Secretariat
• Mr Charles BORY, SINBAD TRG Secretariat