https___en.wikipedia.org_wiki_Research_reactor_4.xml
1.1 2.1 3.1 4.1 4.2 4.3 5.1 5.2 5.3 5.4 5.5
Изследователски реактор Изследователски реактор е ядрен реактор, който се използва за научни цели, а не за производство на енергия (като в атомните електроцентрали), за производство на радиоактивни материали за направата на ядрено оръжие, или за задвижване на превозно средство (например атомна подводница). Техническа характеристика[редактиране | редактиране на кода] Изследователските реактори имат по-малка мощност от тази на реакторите с друго предназначение. Докато един типичен реактор за производство на електричество има топлинна мощност от 3 000 MW (мегавата), изследователските реактори имат мощност между 10 киловата и 10 мегавата. Обединената топлинна мощност на всички 283 изследователски реактора по света е малко над 3 000 MW. Изследователските реактори са по-прости и работят при по-ниски температури. Нуждаят се от по-малко гориво и при "изгарянето" му се натрупват по-малко продукти на разпада. От друга страна, горивото им обикновено е по-силно обогатен уран, обикновено до 20% уран-235, въпреки че някои използват гориво с 93% уран-235. Освен това, голямото съотношение на обем и мощност в ядрото изисква специални похвати в проектирането им. Както и при реакторите за други цели, ядрото се нуждае от охлаждане, което обикновено се постига чрез естествена или принудителна конвекция с вода, както и от неутронен забавител, който да забавя неутроните и реакцията на разпад.
1.1 2.1 2.2 3.1 4.1 5.1 5.2 5.3 6.1 7.1 7.2 7.3 7.4 7.5 7.6 8.1 9.1 9.2 10.1 10.2 11.1 12.1 13.1 14.1 14.2 14.3 14.4 15.1 16.1 17.1 18.1 19.1 20.1 21.1 22.1 23.1 24.1 25.1 26.1 27.1 27.2 27.3 27.4 27.5 30.1 30.2 31.1 31.2 32.1 33.1 33.2 34.1 34.2 35.1 35.2 35.3 36.1 36.2 37.1 37.2 38.1 38.2 39.1 39.2 40.1 40.2 41.1 41.2 42.1 42.2 43.1 43.2 43.3 44.1 44.2 45.1 45.2 45.3 46.1 47.1
Research reactor Research reactors are nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or maritime propulsion. Contents Purpose[edit] The neutrons produced by a research reactor are used for neutron scattering, non-destructive testing, analysis and testing of materials, production of radioisotopes, research and public outreach and education. Research reactors that produce radioisotopes for medical or industrial use are sometimes called isotope reactors. Reactors that are optimised for beamline experiments nowadays compete with spallation sources. Technical aspects[edit] Research reactors are simpler than power reactors and operate at lower temperatures. They need far less fuel, and far less fission products build up as the fuel is used. On the other hand, their fuel requires more highly enriched uranium, typically up to 20% U-235, although some use 93% U-235; while 20% enrichment is not generally considered usable in nuclear weapons, 93% is commonly referred to as "weapons grade". They also have a very high power density in the core, which requires special design features. Like power reactors, the core needs cooling, typically natural or forced convection with water, and a moderator is required to slow the neutron velocities and enhance fission. As neutron production is their main function, most research reactors benefit from reflectors to reduce neutron loss from the core. Conversion to LEU[edit] The International Atomic Energy Agency and the U.S. Department of Energy initiated a program in 1978 to develop the means to convert research reactors from using highly enriched uranium to the use of low enriched uranium, in support of its nonproliferation policy.[1][2] By that time the U.S. had supplied research reactors and highly enriched uranium to 41 countries as part of its Atoms for Peace program. In 2004, the U.S. Department of Energy extended its Foreign Research Reactor Spent Nuclear Fuel Acceptance program until 2019.[3] Also in 2004, the Texas A&M reactor switched to LEU after decades using HEU. These changes are a part of an anti-terrorism initiative since 9/11 begun by the Bush Administration. Designers and constructors[edit] While in the 1950s, 1960s and 1970s there were a number of companies that specialized in the design and construction of research reactors, the activity of this market cooled down afterwards, and many companies withdrew. The market has consolidated today into a few companies that concentrate the key projects on a worldwide basis. The most recent international tender (1999) for a research reactor was that organized by ANSTO for the design, construction and commissioning of the OPAL reactor. Four companies were prequalified: AECL, INVAP, Siemens and Technicatom. The project was awarded to INVAP that built the reactor. In recent years, AECL withdrew from this market, and Siemens and Technicatom activities were merged into AREVA. Classes of research reactors[edit] - Aqueous homogeneous reactor - Argonaut class reactor - DIDO class, six high-flux reactors worldwide - TRIGA, a highly successful class with >50 installations worldwide - SLOWPOKE reactor class, developed by AECL, Canada - Miniature neutron source reactor, based on the SLOWPOKE design, developed by AECL, currently exported by China Research centers[edit] - A more complete list can be found at the List of nuclear research reactors. Research centers that operate a reactor: Decommissioned research reactors: References[edit] - ^ "CRP on Conversion of Miniature Neutron Source Research Reactors (MNSR) to Low Enriched Uranium (LEU)". Nuclear Fuel Cycle & Waste Technology. International Atomic Energy Agency. 13 January 2014. Retrieved 25 October 2015. - ^ a b c "Budapest Research Reactor | Budapest Neutron Centre ...for research, science and innovation!". www.bnc.hu. - ^ "Nuclear Reactors". pd.chem.ucl.ac.uk. - ^ a b "RA-6 de Argentina" (in Spanish). - ^ "Research reactors - Canadian Nuclear Association". Canadian Nuclear Association. - ^ "High Flux Reactor - European Commission". ec.europa.eu. - ^ Mainz, Johannes Gutenberg-Universität. "Reactor". www.kernchemie.uni-mainz.de (in German). - ^ a b "ATI : Reactor". ati.tuwien.ac.at. - ^ a b c "The reactor | National Research Nuclear University MEPhI". eng.mephi.ru. - ^ a b "SAFARI-1". www.necsa.co.za. - ^ a b "High-Flux Advanced Neutron Application Reactor (HANARO) | Facilities | NTI". www.nti.org. - ^ a b "Research Reactor LVR-15 | Centrum výzkumu Řež". cvrez.cz. - ^ a b "History - Nuclear Reactor Program". Nuclear Reactor Program. - ^ a b "Maryland University Training Reactor (MUTR) | 250 kW TRIGA Reactor | University of Maryland Radiation Facilities". radiation.umd.edu/. - ^ "Research Reactor Database - GHARR-1". International Atomic Energy Agency. Retrieved February 15, 2018. - ^ a b "Impulse | Finland's old nuclear research reactor to be decommissioned – New Centre for Nuclear Safety under construction". www.vttresearch.com (in Finnish). - ^ BSS, IAEA - MTIT -. "Header Information - RRDB - IAEA". nucleus.iaea.org. - WNA Information Paper # 61: Research Reactors - Nuclear Nonproliferation: DOE Needs to Take Action to Further Reduce the Use of Weapons-Usable Uranium in Civilian Research Reactors, GAO, July 2004, GAO-04-807