Lead-cooled fast reactor explained

The lead-cooled fast reactor is a nuclear reactor design that use molten lead or lead-bismuth eutectic coolant. These materials can be used as the primary coolant because they have low neutron absorption and relatively low melting points. Neutrons are slowed less by interaction with these heavy nuclei (thus not being neutron moderators) so these reactors operate with fast neutrons.

The concept is generally similar to sodium-cooled fast reactors, and most liquid-metal fast reactors have used sodium instead of lead. Few lead-cooled reactors have been constructed, except for some Soviet nuclear submarine reactors in the 1970s. However, a number of proposed and one in construction new nuclear reactor designs are lead-cooled.

Fuel designs being explored for this reactor scheme include fertile uranium as a metal, metal oxide or metal nitride.[1]

The lead-cooled reactor design has been proposed as a generation IV reactor.Plans for future implementation of this type of reactor include modular arrangements rated at 300 to 400 MWe, and a large monolithic plant rated at 1,200 MWe.

Operation

Lead-cooled fast reactors operate with fast neutrons and molten lead or lead-bismuth eutectic coolant. Molten lead or lead-bismuth eutectic can be used as the primary coolant because especially lead, and to a lesser degree bismuth have low neutron absorption and relatively low melting points. Neutrons are slowed less by interaction with these heavy nuclei (thus not being neutron moderators) and therefore, help make this type of reactor a fast-neutron reactor. In simple terms, if a neutron hits a particle with a similar mass (such as hydrogen in a Pressurized Water Reactor PWR), it tends to lose kinetic energy. In contrast, if it hits a much heavier atom such as lead, the neutron will "bounce off" without losing this energy.The coolant does, however, serve as a neutron reflector, returning some escaping neutrons to the core.

Smaller capacity lead-cooled fast reactors (such as SSTAR) can be cooled by natural convection, while larger designs (such as ELSY[2]) use forced circulation in normal power operation, but will employ natural circulation emergency cooling. No operator interference is required, nor pumping of any kind to cool the residual heat of the reactor after shutdown.The reactor outlet coolant temperature is typically in the range of 500 to 600 °C, possibly ranging over 800 °C with advanced materials for later designs. Temperatures higher than 800 °C are theoretically high enough to support thermochemical production of hydrogen through the sulfur-iodine cycle, although this has not been demonstrated.

The concept is generally very similar to sodium-cooled fast reactor, and most liquid-metal fast reactors have used sodium instead of lead. Few lead-cooled reactors have been constructed, except for some Soviet nuclear submarine reactors in the 1970s, but a number of proposed and one in construction new nuclear reactor designs are lead-cooled.

Fuel

Fuel designs being explored for this reactor scheme include fertile uranium as a metal, metal oxide or metal nitride.[1]

Small modular reactors

See main article: article and Small modular reactor. Reactors that use lead or lead-bismuth eutectic can be designed in a large range of power ratings. The Soviet union was able to operate the Alfa class submarines with a lead-bismuth cooled fast reactor in the sixties and seventies, which had approximately 30 MW of mechanical output for 155 MW thermal power (see below).

Other options include units featuring long-life, pre-manufactured cores, that do not require refueling for many years.

The lead-cooled fast reactor battery is a small turnkey-type power plant using cassette cores running on a closed fuel cycle with 15 to 20 years' refuelling interval, or entirely replaceable reactor modules. It is designed for generation of electricity on small grids (and other resources, including hydrogen production and desalinisation process for the production of potable water).

Advantages of lead in fast reactors

The use of lead as a coolant has several advantages if compared to other methods for reactor cooling.

Disadvantages

Pure lead produces orders of magnitudes less polonium, and so has an advantage over lead-bismuth in this regard.

Implementation

Russia/USSR

Two types of lead-cooled fast reactor were used in Soviet Alfa class submarines of the 1970s. The OK-550 and BM-40A designs were both capable of producing 155MWt. They were significantly lighter than typical water-cooled reactors and had an advantage of being capable to quickly switch between maximum power and minimum noise operation modes.

A joint venture called AKME Engineering was announced in 2010 to develop a commercial lead-bismuth reactor.[6] The SVBR-100 ('Svintsovo-Vismutovyi Bystryi Reaktor' - lead-bismuth fast reactor) is based on the Alfa designs and will produce 100MWe electricity from gross thermal power of 280MWt, about twice that of the submarine reactors. They can also be used in groups of up to 16 if more power is required. The coolant increases from 345C to 495C as it goes through the core. Uranium oxide enriched to 16.5% U-235 could be used as fuel, and refuelling would be required every 7–8 years. A prototype is planned for 2017.[7]

Another two lead cooled reactors are developed by Russians: BREST-300 and BREST-1200.[8] The BREST-300 design was completed in September 2014.[9]

WNA mentions Russia role on boosting other countries interest in this field:[10]

Proposals and in-development

Belgium

The MYRRHA project (for Multi-purpose hYbrid Research Reactor for High-tech Applications) is aimed to contribute to design a future nuclear reactor coupled to a proton accelerator (so-called Accelerator-driven system, ADS). This could be a 'lead-bismuth-cooled,[11] or a lead-cooled, fast reactor' with two possible configurations: sub-critical or critical. It could be a pool-, or a loop-type, reactor.

The project is managed by SCK CEN, the Belgian research center for nuclear energy. It is based on a first small prototype research demonstrator, the Guinevere system, derived from the zero-power reactor Venus existing at SCK CEN since the beginning of the 1960s and modified to host a bath of molten lead-bismuth eutectic (LBE) coupled to a small proton accelerator.[12] [13] In December 2010, MYRRHA was listed by the European Commission[14] as one of 50 projects for maintaining European leadership in nuclear research in the next 20 years. In 2013, the project entered a further development phase when a contract for the front-end engineering design was awarded to a consortium led by Areva.[15] [16]

Aiming at a compact core with high power density (i.e. with a high neutron flux) to be able to operate as a materials testing reactor, the fuel to be used in the ADS MYRRHA must be highly enriched in a fissile isotope. A highly enriched MOx fuel with of was first selected to obtain the desired neutronic performances.[17] [18] [19] However, according to Abderrahim et al. (2005) "this choice should still be checked against the non-proliferation requirements imposed to new test reactors by the RERTR (Reduced Enrichment of fuel for Research Testing Reactors) program launched by US DOE in 1996". So, the fuel to be selected for MYRRHA also needs to respect the criteria of non-proliferation while keeping its neutronic performance. Moreover, such a highly enriched MOx fuel has never been industrially produced and poses severe technical and safety challenges in order to prevent any criticality accident during handling in the factory.

In 2009, under the auspices of the Nuclear Energy Agency (NEA, OECD), an international team of experts (MYRRHA International Review Team, MIRT) examined the MYRRHA project and delivered prudent recommendations to the Belgian government.[20] Beside the technical challenges identified, they were also financial and economical risks related to the construction and exploitation costs expected to strongly increase when the project should enter a more detailed design stage. Long construction delays related to design complications, underestimated technical difficulties and insufficient budget are not uncommon for such a project. The limited participation of the Belgian State (40% of all the costs) and the uncertain benefits for the external project owners were also pointed out.

Because of recurrent financial shortcomings and also important uncertainties still subsisting in the reactor design (pool-, or loop-type, reactor?) and the choice still to be made for the liquid metal coolant (in LBE, is neutron activated producing the highly radiotoxic ⍺-emitting)[21] the front-end engineering design (FEED) activities[22] had to be suspended and have not progressed beyond the preliminary stage.[23] Quite surprisingly, the preliminary results of the FEED activities were published in a journal absolutely not related to the field of ADS or fast neutron reactor: the International Journal of Hydrogen Energy (IJHE) while there was never any question of producing hydrogen with MYRRHA.[24] The choice of this journal to present the preliminary results of the FEED activities is disconcerting. The journal where the FEED activities were announced, Physics Procedia, is also discontinued.[25] Beside continuously increasing costs and financial uncertainties, the project still has to address many technical challenges: severe corrosion issues[26] [27] [28] (liquid metal embrittlement, amalgam-driven dissolution in the molten metal of Cr and Ni from the stainless steel used for the fuel claddings and reactor structure materials), operating temperature (metal solidification risks versus increased corrosion rate), nuclear criticality safety issues...

The mass inventory of the lead-bismuth eutectic (LBE) for the proposed pool-type design of MYRRHA considered in the preliminary FEED analyses of 2013-2015 represents 4500 tons metallic Pb-Bi. This would lead to the production of more than 4 kg of during the reactor operations. After the first operating cycle, 350 g of would already be formed in the LBE exposed to a high neutron flux of the order of 10 neutrons・cm・s, typical for a materials testing reactor (MTR).[29] This would correspond to an activity of 5.5 × 10 becquerels, or 1.49 × 10 curies of, just for the first operation cycle. The presence of such a large ponderable quantity of highly radiotoxic represents a considerable radiological safety challenge for the maintenance operations and the storage of the MYRRHA nuclear fuel. Because of the high volatility of, the plenum space above the reactor could also become alpha-contaminated. As pointed out by Fiorito et al. (2018): "Some polonium will migrate to the cover gas in the reactor plenum and will diffuse outside the primary system when the reactor is opened for refueling or maintenance". All operations in contaminated areas will require appropriate radiological protection measures much more severe than for the handling, or to be completely performed by remotely-operated robots. An envisaged mitigation strategy could consist into a continuous removal of polonium from LBE, but the considerable heat generated by represents a major obstacle.

In 2023, based on interviews with key SCK CEN players and documents publicly available, Hein Brookhuis explored the interactions between the MYRRHA promoters and the Belgian media and political spheres to show how MYRRHA was developed in a narrative that made the project seems essential to the future of SCK CEN, the Belgian nuclear research center.[30]

Germany

The dual fluid reactor (DFR) project was initially developed by a German research institute, the Institute for Solid-State Nuclear Physics, in Berlin. In February 2021, the project was transferred to a newly founded Canadian company, Dual Fluid Energy Inc., to industrialize the concept. The DFR project attempts to combine the advantages of the molten salt reactor with these of the liquid metal cooled reactor.[31] As a fast breeder reactor, the proposed DFR reactor is designed to burn both natural uranium or thorium, as well as transmutating and fissioning minor actinides. Due to the high thermal conductivity of the molten metal, the residual decay heat of a DFR reactor could be passively removed.

Romania

ALFRED (Advanced Lead Fast Reactor European Demonstrator) is a lead cooled fast reactor demonstrator designed by Ansaldo Energia from Italy planned to be built in Mioveni, Romania. ATHENA, a molten lead pool used for research purposes, is going to be built in the same site as well.[32]

Russia

The BREST reactor is currently under construction.[33] This reactor will employ pure lead as coolant, a plutonium/uranium nitride fuel, generate 300 MWe (electric) from 750 MWth, and is a pool type reactor.The foundation has been completed in November 2021. The reactor sits as the Siberian Chemical Combine's (SCC's) Seversk site.

Sweden

The company LeadCold is in collaboration with KTH Royal Institute of Technology and Uniper[34] developing the SEALER (Swedish Advanced Lead Reactor) reactor, a lead-cooled reactor using uranium nitride as fuel.[35]

United Kingdom

British company Newcleo is developing 30 MWe and 200 MWe lead-cooled small modular reactors for naval and land use. The first operational reactor is planned to be deployed in 2030 in France.[36] [37]

United States

The initial design of the Hyperion Power Module was to be of this type, using uranium nitride fuel encased in HT-9 tubes, using a quartz reflector, and lead-bismuth eutectic as coolant. The firm went out of business in 2018.

The Lawrence Livermore National Laboratory developed SSTAR was a lead-cooled design.

See also

Further reading

External links

Notes and References

  1. Allen . T. R. . Crawford . D. C. . Lead-Cooled Fast Reactor Systems and the Fuels and Materials Challenges . Science and Technology of Nuclear Installations . 2007 . 2007 . 1–11 . 10.1155/2007/97486 . free .
  2. Alemberti . Alessandro . Carlsson . Johan . Malambu . Edouard . Orden . Alfredo . Struwe . Dankward . Agostini . Pietro . Monti . Stefano . European lead fast reactor—ELSY . Nuclear Engineering and Design . September 2011 . 241 . 9 . 3470–3480 . 10.1016/j.nucengdes.2011.03.029 .
  3. Web site: High Neutron Reflector Materials.
  4. Web site: BREST-OD-300 (RDIPE, Russian Federation) . 14 August 2024 . www.aris.iaea.org.
  5. Web site: Lead-Cooled Fast Reactor (LFR).
  6. Web site: Initiative for small fast reactors . 2010-01-04 . World Nuclear News . 2010-02-05.
  7. Web site: Heavy metal power reactor slated for 2017 . 2010-03-23 . World Nuclear News . 2012-09-26.
  8. Web site: Design features of BREST reactors and experimental work to advance the concept of BREST reactors . US DoE, Small Modular Reactor Program . 2013-05-16.
  9. Web site: Design completed for prototype fast reactor - World Nuclear News. www.world-nuclear-news.org.
  10. Web site: Nuclear Reactors - Nuclear Power Plant - Nuclear Reactor Technology - World Nuclear Association. www.world-nuclear.org.
  11. Web site: NEA . 2015. Handbook on lead-bismuth eutectic alloy and lead properties, materials compatibility, thermal-hydraulics and technologies – 2015 Edition . Nuclear Energy Agency (NEA) . 2023-12-18.
  12. Web site: Guinevere.
  13. Web site: Reactor-Accelerator Hybrid Achieves Successful Test Run. www.science.org.
  14. Web site: CORDIS | European Commission. 30 April 2014. 22 February 2014. https://web.archive.org/web/20140222152106/http://cordis.europa.eu/result/brief/rcn/11105_fr.html. dead.
  15. Web site: Myrrha accelerates towards realisation - World Nuclear News. www.world-nuclear-news.org.
  16. Web site: Orano | Acteur majeur de l'énergie et du combustible nucléaire. orano.group.
  17. Web site: Tichelen Van, K. . Malambu, E.. Benoit, P. . Kupschus, P. . Ait Abderrahim, H. . Vandeplassche, D. . Ternier, S. . Jongen, Y. . 2001 . MYRRHA: A multipurpose accelerator driven system for research and development . 2023-12-18.
  18. Abderrahim, H. A. . Sobolev, V. . Malambu, E. . October 2005 . Fuel design for the experimental ADS MYRRHA . Technical Meeting on Use of LEU in ADS. October 10–12, 2005 . Vienna, Austria . IAEA . 1–13 .
  19. Van den Eynde . Gert . Malambu . Edouard . Stankovskiy . Alexey . Fernandez . Rafaël . Baeten . Peter . 2015-08-03 . An updated core design for the multi-purpose irradiation facility MYRRHA . Journal of Nuclear Science and Technology . 52 . 7–8 . 1053–1057 . 0022-3131 . 10.1080/00223131.2015.1026860. 2015JNST...52.1053V . 95326619 .
  20. Web site: Carré, F. . Cavedon, J.M. . Knebel, J. . Lisowski, P. . Ogawa, T. . Pooley, D. . Versteegh, A. . Dujardin, T. . Nordborg, C. . 2009-12-16 . Independent Evaluation of the MYRRHA Project. Report by an International Team of Experts. Organised by OECD Nuclear Energy Agency (NEA). Technical Report 6881. English, 44 pages, published: 12/16/09, ISBN 978-92-64-99114-9 .
  21. Eckerman . K. . Harrison . J. . Menzel . H-G. . Clement . C.H. . Clement . CH . ICRP Publication 119: Compendium of Dose Coefficients based on ICRP Publication 60 . Annals of the ICRP . January 2012 . 41 . 1–130 . 10.1016/j.icrp.2012.06.038 . 26 April 2024 . 23025851 . 41299926 .
  22. De Bruyn . Didier . Abderrahim . Hamid Aït . Baeten . Peter . Leysen . Paul . The MYRRHA ADS project in Belgium enters the Front End Engineering phase . Physics Procedia . 66 . 2015 . 10.1016/j.phpro.2015.05.012 . 75–84. 2015PhPro..66...75D . free .
  23. Engelen . Jeroen . Aït Abderrahim . Hamid . Baeten . Peter . De Bruyn . Didier . Leysen . Paul . 2015 . MYRRHA: Preliminary Front-End Engineering Design . International Journal of Hydrogen Energy . 40 . 44 . 15137–15147 . 10.1016/j.ijhydene.2015.03.096.
  24. International Journal of Hydrogen Energy . ScienceDirect.com by Elsevier . 2023-12-19.
  25. Physics Procedia. Title discontinued as of 2018 . ScienceDirect.com by Elsevier . 2015-06-20 . 2023-12-19.
  26. Allen . T. R. . Crawford . D. C. . Lead-cooled fast reactor systems and the fuels and materials challenges . Science and Technology of Nuclear Installations . 2007 . 2007 . 1687-6075 . 10.1155/2007/97486 . 1–11 . free .
  27. Zhang . J. . Li . N. . 2004 . Review of studies on fundamental issues in LBE corrosion. LA-UR-04-0869 . Los Alamos National Laboratory (LANL).
  28. Zhang . Jinsuo . Li . Ning . 2008 . Review of the studies on fundamental issues in LBE corrosion . Journal of Nuclear Materials . 373 . 1–3 . 351–377 . 10.1016/j.jnucmat.2007.06.019. 2008JNuM..373..351Z .
  29. Fiorito . Luca . Stankovskiy . Alexey . Hernandez-Solis . Augusto . Van den Eynde . Gert . Žerovnik . Gasper . 2018 . Nuclear data uncertainty analysis for the Po-210 production in MYRRHA . EPJ Nuclear Sciences & Technologies . 4 . 48 . 2491-9292 . 10.1051/epjn/2018044. 2018EPJNS...4...48F . free .
  30. Brookhuis . Hein . Making Belgian Big Science . Historical Studies in the Natural Sciences . 53 . 1 . 2023-02-01 . 1939-1811 . 10.1525/hsns.2023.53.1.35 . 35–70. free .
  31. Web site: Dual Fluid Reaktor.
  32. Web site: Generation IV & SMR. www.ansaldoenergia.com.
  33. Web site: Foundation set in place for BREST reactor : New Nuclear - World Nuclear News.
  34. Web site: Collaboration with Uniper and KTH . 2022-05-03 . www.leadcold.com . 3 May 2022 . https://web.archive.org/web/20220503060139/https://www.leadcold.com/collaboration-with-uniper-and-kth.html . dead .
  35. Web site: SEALER . 2022-05-03 . www.leadcold.com . 31 March 2022 . https://web.archive.org/web/20220331024505/http://www.leadcold.com/sealer.html . dead .
  36. News: 2023-09-17. UK's Newcleo to raise $1.1 bln to build fleet of small reactors - The Times. Reuters. 19 March 2023. www.reuters.com.
  37. News: 2023-09-17. Nuclear power: 'Newcleo is on its way to becoming Europe's best-funded start-up'. Le Monde.fr. 21 March 2023. Le Monde.