WO1994005012A1 - Boulettes de combustible pour reacteurs nucleaires refroidis par liquide - Google Patents

Boulettes de combustible pour reacteurs nucleaires refroidis par liquide Download PDF

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Publication number
WO1994005012A1
WO1994005012A1 PCT/DE1993/000756 DE9300756W WO9405012A1 WO 1994005012 A1 WO1994005012 A1 WO 1994005012A1 DE 9300756 W DE9300756 W DE 9300756W WO 9405012 A1 WO9405012 A1 WO 9405012A1
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WO
WIPO (PCT)
Prior art keywords
fuel
pellet
nuclear
fuel pellet
temperature
Prior art date
Application number
PCT/DE1993/000756
Other languages
German (de)
English (en)
Inventor
Günter LOHNERT
Herbert Reutler
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO1994005012A1 publication Critical patent/WO1994005012A1/fr

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Classifications

    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
    • G21C3/02—Fuel elements
    • G21C3/04—Constructional details
    • G21C3/16—Details of the construction within the casing
    • G21C3/20—Details of the construction within the casing with coating on fuel or on inside of casing; with non-active interlayer between casing and active material with multiple casings or multiple active layers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Definitions

  • the invention relates to a fuel pellet for a liquid-cooled nuclear reactor, in which one fuel is subjected to a nuclear reaction, which fuel pellet can be arranged alone or in groups in a cladding tube to form a fuel rod.
  • the fuel for liquid-cooled nuclear reactors is usually provided in the form of pellets, in particular tablets, made of uranium oxide and / or uranium carbide, which are pressed and sintered from the corresponding powder; these pellets are usually arranged in large numbers in cladding tubes to form fuel rods.
  • Cladding tubes generally consist of zirconium or alloyed zirconium and, under normal operating conditions, ensure essentially complete retention of the Reaction products that are released during the nuclear reaction taking place in the fuel.
  • spherical fuel elements instead of the fuel rods in liquid-cooled nuclear reactors, in which fuel particles containing uranium oxide with an average size of about 500 ⁇ m, which are embedded in a graphite matrix, are used .
  • the fuel particles are coated with silicon carbide and are known as "coated particles".
  • the coating of the fuel particles very reliably fulfills the function of safely retaining the reaction products formed in the fuel by the nuclear reaction. It could also be shown experimentally that such fuel particles can be tur prolonged exposure (for example, 500 hours) a Tempera ⁇ up to 1600 C ⁇ without the safe retention is limited.
  • a helium-cooled high-temperature nuclear reactor has been described in DE-C 30 16 402, which is so limited in its dimensions and consequently also in its output that the disturbances described above, in particular when completely shut down ⁇ case of all active cooling systems, the fuel elements never reach a temperature that is above the temperature of a safe retention of the fission products by the coating of the fuel particles.
  • the high-temperature nuclear reactor is updated ⁇ staltet that at each possible fault, the fuel reach a temperature of at most about 1600 * C.
  • a fuel assembly for a water-cooled nuclear reactor is described for example in DE 37 36 565 AI. This fuel assembly has fuel rods made of zircon or a zirconium alloy and containing fuel pellets.
  • the fuel rods serve, in particular, as already mentioned, to safely retain the reaction products formed by the nuclear reaction in the actual fuel.
  • the temperature resistance of the fuel element is therefore largely determined by the temperature resistance, in particular the melting point of the fuel rods. Therefore the safe retention of the reaction products is guaranteed up to this melting point.
  • the invention is based on the object of specifying a fuel pellet for a liquid-cooled nuclear reactor in which one fuel is subjected to a nuclear reaction, which fuel pellet can be arranged alone or in groups in a cladding tube to form a fuel rod, in which the reaction products are reliably retained even in the event of a malfunction that causes the core of the reactor to melt.
  • a fuel pellet which is intended for use in a liquid-cooled nuclear reactor and in which a fuel is subjected to a nuclear reaction and which can be arranged alone or in groups in a cladding tube to form a fuel rod and off there are a large number of fuel-containing fuel particles, each of which is provided with a coating which is essentially impenetrable for reaction products of the nuclear reaction even when the fuel pellet is exposed to a temperature which occurs when a nuclear reactor melts Temperature corresponds.
  • the term “essentially” means that the release of reaction products from a fuel pellet is limited to a few percent of the total reaction products present in the fuel pellet.
  • the fuel in the fuel pellet advantageously has uranium oxide and / or uranium carbide, and the covering of each fuel particle has a layer of zirconium carbide. Resistance up to 3000 ° C in hydrogen atmosphere has been demonstrated for such fuel particles.
  • the fuel pellet is conveniently shaped into a tablet and can therefore be used in a conventional fuel rod
  • Fuel element for a liquid-cooled, in particular water-cooled, nuclear reactor can be arranged.
  • the fuel particles of the fuel pellet are advantageously stored in a matrix of a binder; graphite is particularly suitable as a binder.
  • the fuel particles in the fuel pellet are, without prejudice to other configurations of the fuel pellet, advantageously approximately spherical and are therefore particularly suitable for powder-metallurgical processes for producing the fuel pellet.
  • the coating of each fuel particle is in the pellet Brennstoff ⁇ preferably up to a temperature of about 2500 * C substantially impenetrable, whereby the secure retention of reaction products in virtually any imaginable accident core melt is secured.
  • the invention also relates to the use of a fuel pellet in a nuclear reactor cooled with a liquid, in particular water, the fuel pellet being able to be arranged on its own or in a cladding tube to form a fuel rod and having a multiplicity of fuel-containing fuel particles, each of which are provided with a covering which is essentially impenetrable for fission products of the nuclear reaction even when the fuel pellet is exposed to a temperature which corresponds to a temperature in the event of a meltdown of the nuclear reactor.
  • the properties of the essentially impenetrable sheathing are exploited in such a way that a reliable retention of reaction products of the nuclear reaction is ensured in a liquid-cooled nuclear reactor for every conceivable disturbance.
  • the fuel is a substance that can be split by thermal neutrons, in particular uranium, and the nuclear reaction is a nuclear fission. Accordingly, a nuclear reactor in which uranium or a comparable substance is split by thermal neutrons can be operated practically completely safely with a view to avoiding the release of reaction products.
  • design parameters of a liquid-cooled nuclear reactor in which a fuel pellet according to the invention is to be used should be changed in such a way that that the time and temperature limits set by the properties of the coating of the fuel particles are not exceeded in the event of a fault. This can be done by reducing the power density of the nuclear reactor.
  • a suitable design of a basin intended for receiving a molten reactor core for the purpose of cooling the melt as quickly as possible, for example by enlarging a surface of the basin that is in contact with the soil, would also reduce the load on the coating of the fuel particles, namely in that shortly after the disturbance occurs, the temperature of the melt is significantly reduced.
  • the single figure shows a fuel pellet 1 in the form of a tablet, specifically a tablet with chamfered edges with respect to an axis 6.
  • the fuel pellet 1 has approximately spherical fuel particles 2 which are embedded in a matrix 5 consisting of a binder, in particular graphite.
  • Each fuel particle 2 contains fuel 3 inside, which is surrounded by an envelope 4.
  • Materials for the cladding 4 are selected so that even at a temperature which is a maximum temperature in the event of a core meltdown of a nuclear reactor in which the fuel pellet 1 is used and the fuel 3 of a nuclear reaction, in particular nuclear fission by thermal neutrons , is subjected, corresponds to, is essentially impenetrable for reaction products which have formed or are formed in the fuel 3 as a result of the nuclear reaction.
  • the fuel pellet according to the invention for a liquid-cooled nuclear reactor makes it possible to ensure safe retention of reaction products from a nuclear reaction to which the fuel has been subjected to the fuel pellet, even when the fuel pellet is exposed to a temperature which occurs when a nuclear reactor melts Temperature corresponds.

Abstract

Une boulette de combustible (1) pour un réacteur nucléaire refroidi par liquide, dans lequel un combustible (3) est soumis à une réaction nucléaire, peut constituer toute seule ou à plusieurs un crayon combustible dans un tube de gainage. La boulette de combustible (1) comprend une pluralité de particules (2) contenant du combustible pourvues chacune d'une gaine qui reste impénétrable par les produits de la réaction nucléaire même lorsque la boulette de combustible (1) est exposée à une température qui correspond à la température survenant lors d'un accident entraînant la fusion du noyau du réacteur nucléaire. Cette boulette de combustible (1) assure même dans le cas d'un réacteur nucléaire refroidi à l'eau une retenue fiable des produits de réaction lors de toutes défaillances imaginables.
PCT/DE1993/000756 1992-08-21 1993-08-19 Boulettes de combustible pour reacteurs nucleaires refroidis par liquide WO1994005012A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4227795A DE4227795A1 (de) 1992-08-21 1992-08-21 Kernreaktor-Brennstoffelement
DEP4227795.7 1992-08-21

Publications (1)

Publication Number Publication Date
WO1994005012A1 true WO1994005012A1 (fr) 1994-03-03

Family

ID=6466115

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE1993/000756 WO1994005012A1 (fr) 1992-08-21 1993-08-19 Boulettes de combustible pour reacteurs nucleaires refroidis par liquide

Country Status (2)

Country Link
DE (1) DE4227795A1 (fr)
WO (1) WO1994005012A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4433032C1 (de) * 1994-09-16 1996-01-04 Forschungszentrum Juelich Gmbh Kernreaktor mit Druckbehälter und Wasser als Kühlmittel und Moderator sowie Verfahren zum Betreiben des Kernreaktors
FR2807563B1 (fr) * 2000-04-07 2002-07-12 Framatome Sa Assemblage de combustible nucleaire pour un reacteur refroidi par de l'eau legere comportant un materiau combustible nucleaire sous forme de particules

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1074426A (en) * 1964-09-28 1967-07-05 Minnesota Mining & Mfg Improvements in or relating to nuclear fuels
GB1376365A (en) * 1973-02-07 1974-12-04 Atomic Energy Authority Uk Nuclear fuel compacts
JPH02159597A (ja) * 1988-12-12 1990-06-19 Nuclear Fuel Ind Ltd 硬化オーバーコート被覆燃料粒子およびそれを使用した核燃料体の製造方法
EP0376583A1 (fr) * 1988-12-29 1990-07-04 General Atomics Particules de combustible nucléaire et méthode de fabrication d'agglomérés de combustible nucléaire

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3039944A (en) * 1959-05-13 1962-06-19 Zumwalt Lloyd Robert Fuel element
DE2207655C3 (de) * 1972-02-18 1979-04-12 Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe Verfahren zur Verbesserung der Verträglichkeit oxidischer Kernbrennstoffe mit den Materialien der sie umgebenden Brennelement-Hüllen
DE3016402A1 (de) * 1980-04-29 1981-11-05 GHT Gesellschaft für Hochtemperaturreaktor-Technik mbH, 5060 Bergisch Gladbach Hochtemperaturreaktor in modul-bauweise
DE3736565C2 (de) * 1987-10-28 1995-12-14 Siemens Ag Kernreaktorbrennelement

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1074426A (en) * 1964-09-28 1967-07-05 Minnesota Mining & Mfg Improvements in or relating to nuclear fuels
GB1376365A (en) * 1973-02-07 1974-12-04 Atomic Energy Authority Uk Nuclear fuel compacts
JPH02159597A (ja) * 1988-12-12 1990-06-19 Nuclear Fuel Ind Ltd 硬化オーバーコート被覆燃料粒子およびそれを使用した核燃料体の製造方法
EP0376583A1 (fr) * 1988-12-29 1990-07-04 General Atomics Particules de combustible nucléaire et méthode de fabrication d'agglomérés de combustible nucléaire

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 014, no. 415 (P - 1102) 7 September 1990 (1990-09-07) *

Also Published As

Publication number Publication date
DE4227795A1 (de) 1994-02-24

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