On June 12, at a conference organized by the Polish Union of Entrepreneurs and Employers, the conceptual design of a new Polish high-temperature research reactor developed at NCBJ was presented to the public for the first time. The helium-cooled reactor will provide 30 MW of thermal power, and the helium temperature at the outlet of the primary cooling circuit will reach 750 ⁰C.

The conceptual design of the research reactor, for which the name HTGR-POLA is proposed, was developed by the team of the Department of Nuclear Energy and Environmental Analysis of the National Center for Nuclear Research, working under the leadership of prof. dr hab. Mariusz Dabrowski.

Basic technical parameters of HTGR-POLA:

• Reactor core of the prismatic type consisting of hexagonal blocks.
• Maximum reactor thermal power 30 MWt.
• TRISO type fuel with 8-12% enrichment. Details will be made during the development of the basic design after the final simulations have been performed.
• Open fuel cycle.
• The moderator is graphite.
• Primary forced circulation helium cooling circuit at 6 MPa pressure.
• Helium temperature at the reactor outlet 750 ⁰C, at the inlet 325 ⁰C.
• The external dimensions of the reactor pressure vessel are: diameter 4.1 m and height 12.3 m.
• Secondary water-steam cooling circuit at 13.8 MPa pressure.
• Passive and active safety systems.
• Reactivity control through a system of control elements (rods), reactivity reducing materials permanently housed in the fuel blocks, and reserve reactivity reducing capsules.
• The planned lifetime of the reactor is 60 years.
• Possible cogeneration operation: maximum gross electric power is 10 MWe, maximum power of high-temperature steam with a temperature of 540 ⁰C.
• for industrial processes 17 MWt with a maximum capacity of 25 t/h, maximum production of low-temperature steam for municipal purposes 16.5 MWt.

The project was prepared in cooperation with the Japan Atomic Energy Agency (JAEA), which has its own HTTR gas-cooled high-temperature reactor. The conceptual design is the starting point for the development of the basic design, which will also include safety analyzes and tests of the reactor's construction materials.

The conceptual design was presented to the public for the first time on June 12, 2023 by Dr. Józef Sobolewski, the representative of the NCBJ director for the development of high-temperature reactors. The presentation took place at the conference organized in Warsaw by the Union of Entrepreneurs and Employers under the title "SMR - Modular Atom for Business (Poland as an incubator of SMR technology in Europe?)". The honorary patron of the event was also NCBJ. The conference gathered about 150 people, including representatives of all the most important participants involved in the SMR market in Poland. Details are available on the conference organizer's website (https://zpp.net.pl/). NCBJ was represented by the director of NCBJ, prof. K. Kurek, and Dr. J. Sobolewski presenting the NCBJ activities in the field of high-temperature reactors.

NCBJ's work on the high-temperature reactor is financed as part of the project of the Minister of Education and Science under the name "Technical description of the research High-Temperature Gas-cooled Reactor (HTGR)" in the years 2021 - 2024 funding amount PLN 60,000,000.00 gross, contract no. 1/HTGR/2021/14.

Graphics: 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. (Source: NCBJ)