Poland’s National Centre for Nuclear Research (NCBJ – Narodowe Centrum Badań Jądrowych) has unveiled the conceptual design for a new high-temperature gas-cooled research reactor, to be called HTGR-POLA. The helium-cooled reactor will provide 30 MW of thermal power.

The design was developed by a team from the Department of Nuclear Energy & Environmental Analysis at NCBJ led by Dr Mariusz Dabrowski. The project was developed in cooperation with the Japan Atomic Energy Agency (JAEA), which operates the which operates the 30 MWt High-Temperature Test Reactor (HTTR), which is graphite-moderated and uses helium gas as a coolant.

The conceptual design was presented for the first time by Dr Józef Sobolewski. The presentation took place at a conference in Warsaw organised by the Union of Entrepreneurs & Employers titled "SMR – Modular Atom for Business (Poland as an incubator of SMR technology in Europe?)". NCBJ said the conceptual design “is the starting point for the development of the basic design, which will also include safety analyses and tests of the reactor's construction materials”.

NCBJ's work on the high-temperature reactor is financed through a Ministry of Education & Science project, "Technical description of research on a High-Temperature Gas-cooled Reactor (HTGR)" running from 2021 to 2024. Funding for the project totals PLN60m ($14.7m under contract 1/HTGR/2021/14.

The helium-cooled reactor (12.3 metres high with a diameter of 4.1 metres) will feature a prismatic-type core comprising hexagonal blocks moderated with graphite. It will feature passive and active safety systems, with a planned design life of 60 years. The reactor will use TRISO-type fuel with 8-12% enrichment. The primary forced circulation helium cooling circuit will operate at a pressure of 6 MPa. The helium temperature at the reactor outlet will be 750°C, at the inlet 325°C.

In November 2022, an agreement between JAEA and NCBJ added the basic design of the research reactor to their ongoing collaborative R&D on HTGR technology. The agreement supplements an earlier agreement by providing for R&D cooperation on the research reactor.

The International Atomic Energy Agency TECDOC, “Advances in Small Modular Reactor Technology Developments” lists 14 HTGRs, worldwide, three of which are operating – Japan’s HTTR and China’s HTR-10 and HTR-PM. The others are all in the design stage.

Image: Cross-section of the designed reactor. Core blocks with fuel channels are marked in red, reflector blocks with cooling channels in orange, reflector blocks with control rod channels in yellow, other reflector blocks in green, and fixed reflector blocks in blue. Next to the reactor is the pressure vessel of the steam generator (courtesy of NCBJ)