Very High Temperature Reactors GIF System Steering Committee

The Very High Temperature Reactor System Steering Committee (VHTR SSC) was established after the VHTR System Arrangement was signed in 2006. Presently, nine members of the Generation IV International Forum (GIF) participate in the VHTR SSC's activities. This committee oversees four projects that cover a broad range of topics related to Very High Temperature Reactors. The VHTR, along with Sodium Fast Reactors, is one of the Generation IV systems that has commercial-scale power reactors in operation today and has also had several in operation previously.

DISCLAIMER: The entry into force of the 2025 GIF Framework Agreement on 1st March 2025 brings changes to the GIF membership. The website will be updated in due course to reflect these changes.

Activities and Membership of the Very High Temperature Reactors GIF System Steering Committee

GIF VHTR SSC gathers ten GIF Members. It oversees four R&D cooperation projects. 

AU
Australia
CA
Canada
CN
People’s Republic of China
EU
Euratom
JP
Japan
KR
Republic of Korea
RU
Russian Federation
CH
Switzerland
GB
United Kingdom
US
United States

VHTR Projects

Project ArrangementProject DescriptionEffective Date

SIGNATORIES

 

(GIF Member)

Fuel and Fuel Cycle (FFC)The Fuel and Fuel Cycle project focuses on developing solutions for VHTR fuel, specifically TRISO-coated particles. The project explores potential fuel development such as uranium oxycarbide kernels or ZrC coatings to improve burnup capability, reduce fission product release, and increase resistance to core heat-up accidents. 

2008

INET (CN)
JRC (EU)
CEA (FR)
JAEA (JP)
KAERI (KR)
DOE (US)

Computational Methods, Validation & Benchmarks (CMVB)Validation of new computational methods and codes in the areas of HTR thermal-hydraulics, thermal mechanics, core physics and chemical transport are needed for the design and licensing assessment of reactor performance in accident conditions.

2013

INET (CN)
JRC (EU) 
JAEA (JP)
KAERI (KR) 
DOE (US)

Hydrogen Production (HP)Recent Project focus has been on the hybrid copper-chlorine thermo-chemical and the hybrid sulfur cycles. R&D efforts in this PMB address material development, feasibility, optimization, efficiency and economic evaluation for industrial-scale hydrogen production. Performance and optimization of hydrogen production processes are being assessed through integrated test loops, from laboratory 

2008

NRCan (CA)
JRC (EU)
CEA (FR)
JAEA (JP)
KAERI (KR)
DOE (US)

Material (MAT)VHTR-MAT PMB mainly focuses on advanced materials development, additional materials’ testing standard and code development, and develops and maintains the “GenIV materials handbook”. The Gen IV Materials Handbook, initially developed for the US Gen IV Nuclear Energy Systems Program, became the shared international database it is today starting from April 2007. The handbook evolved into a sophisticated materials information management system with secured access control, data processing tools, and a flexible framework for enhancement, aiming to satisfy the research needs of international Gen IV nuclear reactor programs.

2009

ANSTO (AU)
NRCan (CA) - joined in 2024
INET (CN)
JRC (EU)
CEA (FR)
JAEA (JP)
KAERI (KR)
PSI (CH)
DESNZ (UK) -joined in 2024
DOE (US)

If you want to learn more about the Very High Temperature Reactor technology head to the VHTR System description page. If you want to learn more about the latest outcomes and international efforts carried out under the GIF VHTR SSC please refer to the most recent GIF Annual Report. 

VHTR SSC Leadership & Technical Secretariat

Portrait of Dr Strydom

Dr
Gerhard STRYDOM

VHTR SSC
VHTR SSC Chair

Dr. Gerhard Strydom is the National Technical Director for the United States Department of Energy’s
(DOE) Advanced Reactor Technologies (ART) Gas-Cooled Reactors (GCR) campaign. He is
responsible for overseeing the ART GCR program activities on graphite and high-temperature
materials qualification, as well as GCR simulation method development and validation at Idaho
National Laboratory (INL). He represents the US DOE on the IAEA GCR Technical Working Group
(TWG) and the Generation-IV Forum (GIF) Expert Group since 2016. Until October 2024, he served for
4 years as the Chair of the GIF Very High Temperature Reactor (VHTR) System Steering Committee.
He is the author of more than 80 technical publications, including 53 journal and conference papers,
and received his Ph.D. on the development of a multi-phase and multi-physics uncertainty assessment
methodology for prismatic GCRs in September 2020.

Mr
Ali SIDDIQUI

VHTR SSC
VHTR SSC Co-chair
Brent WILHELM

Mr
Brent WILHELM

GIF TS
NECAWG
VHTR SSC
GIF Technical Secretary

Brent Wilhelm is a Nuclear Energy Analyst in the Division of Nuclear Technology and Economics within the Nuclear Energy Agency. Brent also serves the Generation IV International Forum (GIF) as Technical Secretary to support international R&D efforts on advanced gas-cooled reactor technologies, and the use of nuclear energy for non-electric applications. 
Prior to this role, Brent worked for the Government of Canada as a Nuclear Science and Technology Advisor with Natural Resources Canada, where he informed analysis on nuclear energy technologies in support of Canada’s strategic policies. He has also worked at Canadian Nuclear Laboratories, Bell Canada, and GreenBug Energy, where he gained practical experience in clean energy technology development and the management of infrastructure implementation projects. 
Brent received both a MSc and BSc in Physics from the University of Guelph where he specialized in nuclear energy and planetary bulk geochemistry. 

Portrait of Dr Elena Poplavskaia GIF TS

Dr
Elena POPLAVSKAIA

GIF TS
AMMEWG
VHTR SSC
GIF Technical Secretary

Elena Poplavskaia is a Nuclear Scientist in the division of the Nuclear Science and Education and Data Bank at the OECD/NEA. She also provides Technical Secretariat for the Generation IV International Forum (GIF) supporting the SCWR Steering Committee, SCWR Project Management Boards on Thermal-hydraulics and Safety, Materials and Chemistry, SCWR provisional Project Management Board on System Integration and Analysis, the VHTR Fuel and Fuel Cycle Project Management Board and the Advanced Manufacturing and Materials Engineering Working Group.

Prior joining the NEA in 2013 she was the head of a Research Centre laboratory, where she led the activities on system analysis of nuclear energy systems including advanced fast reactors and closed fuel cycle technologies, innovative institutional approaches to nuclear energy deployment and long-term aspects of achieving sustainability in the cycle. She was also involved in co-operation with the IAEA INPRO project. She holds a PhD in Engineering Science.