DE19502540A1 - Nuclear power station fuel rod safety system - Google Patents
Nuclear power station fuel rod safety systemInfo
- Publication number
- DE19502540A1 DE19502540A1 DE19502540A DE19502540A DE19502540A1 DE 19502540 A1 DE19502540 A1 DE 19502540A1 DE 19502540 A DE19502540 A DE 19502540A DE 19502540 A DE19502540 A DE 19502540A DE 19502540 A1 DE19502540 A1 DE 19502540A1
- Authority
- DE
- Germany
- Prior art keywords
- fuel rod
- cavern
- melt
- protection
- nuclear reactors
- Prior art date
- Legal status (The legal status 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 status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C9/00—Emergency protection arrangements structurally associated with the reactor, e.g. safety valves provided with pressure equalisation devices
- G21C9/02—Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse; Control elements having arrangements activated in an emergency
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C9/00—Emergency protection arrangements structurally associated with the reactor, e.g. safety valves provided with pressure equalisation devices
- G21C9/016—Core catchers
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Structure Of Emergency Protection For Nuclear Reactors (AREA)
Abstract
Description
Die Erfindung betrifft eine Kavernensicherung für Kernreaktoren nach dem Oberbegriff des Anspruchs 1. Die vorgegebene Kavernen sicherung dient zum Schutz vor Überhitzung der Brennstäbe.The invention relates to cavern protection for nuclear reactors according to the preamble of claim 1. The given caverns fuse is used to protect the fuel rods from overheating.
Es ist bekannt, daß mehrere Pumpensysteme bzw. Moderatoren ein zu starkes Aufheizen verhindern soll. Trotz all dieser Maßnah men ist aber eine Kernschmelze nicht ausgeschlossen, da es zu Totalausfällen auch der Notkühlsysteme kommen kann. Zu würdigen ist hier das US-Patent 4,036,688. Es wird eine Anordnung be schrieben, welche aus einer Auffangvorrichtung mit Verteilungs räumen besteht, in welche sich der geschmolzene Reaktorkern nach dem Durchdringen des Reaktordruckgefäßes einbringt. Die Vorrich tung ist unter dem Reaktordruckgefäß angebracht. Eine zusätzlich eingebaute Kühlung soll das Durchdringen der Sicherung durch die glühende Masse verhindern. Die Stellen, auf welche das Material zuerst auftrifft, sind kalottenförmig ausgelegt, so daß ein wei terer Schutz entsteht, da die zum Reaktordruckgefäß gewölbten massiven Halbkugeln erst wegschmelzen müssen, bevor der Grund des Apparates, der aus Ziegelsteinen besteht, in Mitleidenschaft gezogen würde. Sie tragen außerdem zur Verteilung der geschmolze nen Stoffe in die schräg gestellten Kavernen bei. Diese Sicherung hat allerdings den Nachteil, daß eine zusätzliche Kühlung benötigt wird, welche ausfallen kann. Der GAU ist dann nicht mehr zu ver hindern. Außerdem nimmt die Erfindung eine Zerstörung des Reak tordruckgefäßes in Kauf. Der gesamte Kernreaktor ist danach nicht mehr zu verwenden, eine Kühlung auf unabsehbare Zeit muß gewähr leistet werden. Dies ist bei der vorliegenden Anmeldung nicht der Fall. Da ein direkter Zugriff auf die Brennstäbe nicht möglich ist, muß eine spezielle interne Sicherungseinrichtung die Kernschmelze verhindern. Dies wird durch die Kavernensicherung erreicht. Bei Übersteigen einer kritischen, durch Dichte und Material der Schmelz schicht bestimmbaren Temperatur schmilzt diese für den betroffenen Brennstab an der Sollbruchstelle durch und er fällt in eine von Moderatormaterial umgebende Kaverne, welche die Kernreaktion unter bricht. Bei genügend starker Auslegung des Moderatormaterials kann eine Überhitzung des Brennstabes ohne weitere Kühlung ausgeschlossen werden. Selbst wenn nur ein Teil der Brennstäbe ausfällt, ist die Kernschmelze verhindert, da eine Kettenreaktion ausfällt, bzw. zum Stillstand kommt. Die Kaverne muß so ausgelegt werden, daß die ge samte Energie des Brennstabes aufgenommen werden kann.It is known that several pump systems or moderators should prevent excessive heating. Despite all this measure However, a meltdown is not ruled out because it is too Total failures of the emergency cooling systems can also occur. Appreciate here is U.S. Patent 4,036,688. There will be an arrangement wrote which from a fall arrester with distribution there is space in which the molten reactor core is located penetration of the reactor pressure vessel. The Vorrich device is attached under the reactor pressure vessel. An additional one built-in cooling is said to penetrate the fuse through the prevent glowing mass. The places on which the material first hits are dome-shaped, so that a white Further protection arises because the bulges facing the reactor pressure vessel massive hemispheres must first melt away before the reason the apparatus, which consists of bricks, is affected would be drawn. They also contribute to the distribution of the melted in the inclined caverns. This backup has the disadvantage, however, that additional cooling is required which can fail. The GAU can then no longer be verified prevent. The invention also assumes destruction of the reak gate pressure vessel in purchase. The entire nuclear reactor is not after that more to use, cooling for an indefinite period must guarantee to be achieved. This is not the case with the present application Case. Since direct access to the fuel rods is not possible, must have a special internal safety device the meltdown prevent. This is achieved through cavern protection. At Exceed a critical, by density and material of the enamel layer-definable temperature melts this for the affected Fuel rod through at the predetermined breaking point and it falls into one of Cavern surrounding moderator material, which under the nuclear reaction breaks. With a sufficiently strong interpretation of the moderator material can overheating of the fuel rod is excluded without further cooling will. Even if only some of the fuel rods fail, that is Meltdown prevented because a chain reaction fails, or to Standstill comes. The cavern must be designed so that the ge entire energy of the fuel rod can be absorbed.
Fig. 1 zeigt ein Ausführungsbeispiel der Kavernensicherung im Schnitt. Fig. 1 shows an embodiment of the cavern security in section.
Es folgt die Erläuterung der Erfindung an Hand der Zeichnungen und nach Wirkungsweise. In Fig. 1 ist eine Kavernensicherung gezeichnet. Sie besteht aus einer unmittelbar unter dem Brenn stab a im Reaktordruckgefäß angebrachten, auswechselbaren Platte b und einer sich anschließenden Kaverne c, welche mindestens die Länge des Brennstabes aufweist. Diese Kaverne besteht aus Neutronen- absorbierendem Material, z. B. Graphit. Im Normalfall soll die höchste im Normalbetrieb des Reaktors auftretende Brennstab temperatur nur wenige Grad Kelvin unterhalb der Schmelztempe ratur der mit Sollbruchstellen ausgestatteten, auswechselbaren Platte b liegen. Steigt die Temperatur auch nur eines einzigen Brennstabes, wobei Fig. 1 die Anordnung für nur einen Brennstab zeigt, unzulässig über diese Marke an, schmilzt die nur wenige cm dicke Schicht an der Sollbruchstelle durch, und die Kaverne ist offen. Der Brennstab fällt hinein; er wird vom Graphitmantel eingeschlossen und ist der Kernreaktion entzogen, wobei er sich abkühlt. Fallen weitere Stäbe auf Grund ihrer Überhitzung aus, kommt schließlich der gesamte Kernreaktor zum Stillstand, weil die Menge der außerhalb der Kavernen verbleibenden Brennstäbe nicht mehr ausreicht, die Kernspaltung aufrecht zu erhalten. Der GAU ist abgewendet. Es ist kein strahlendes Material aus dem Reaktordruckgefäß entwichen, welches auch nicht zerstört wurde. Nach Instandsetzung der ausgefallenen Kühlung oder sonsti ger auslösender Fehlfunktionen können die Brennstäbe in ihre alte Position gebracht werden, die Schmelzschicht wird ausge wechselt, man kann den Reaktor erneut anfahren.There follows the explanation of the invention with reference to the drawings and according to the mode of action. A cavern safety device is drawn in FIG. 1. It consists of an interchangeable plate b attached directly under the fuel rod a in the reactor pressure vessel and an adjoining cavern c, which has at least the length of the fuel rod. This cavern is made of neutron absorbing material, e.g. B. Graphite. Normally, the highest fuel rod temperature that occurs during normal operation of the reactor should be only a few degrees Kelvin below the melting temperature of the exchangeable plate b equipped with predetermined breaking points. If the temperature of even a single fuel rod rises, whereby FIG. 1 shows the arrangement for only one fuel rod, beyond this mark, the layer which is only a few cm thick melts at the predetermined breaking point, and the cavern is open. The fuel rod falls into it; it is enclosed in the graphite shell and is withdrawn from the nuclear reaction, cooling off. If further rods fail due to overheating, the entire nuclear reactor finally comes to a standstill because the quantity of fuel rods remaining outside the caverns is no longer sufficient to maintain the nuclear fission. The worst case scenario has been averted. No radiant material has escaped from the reactor pressure vessel and has not been destroyed. After repairing the failed cooling system or other malfunction that triggers the fuel rods can be returned to their old position, the melt layer is replaced, and the reactor can be restarted.
Claims (5)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19502540A DE19502540A1 (en) | 1994-05-17 | 1995-01-18 | Nuclear power station fuel rod safety system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE4417207 | 1994-05-17 | ||
DE19502540A DE19502540A1 (en) | 1994-05-17 | 1995-01-18 | Nuclear power station fuel rod safety system |
Publications (1)
Publication Number | Publication Date |
---|---|
DE19502540A1 true DE19502540A1 (en) | 1996-02-15 |
Family
ID=6518256
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19502540A Withdrawn DE19502540A1 (en) | 1994-05-17 | 1995-01-18 | Nuclear power station fuel rod safety system |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE19502540A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007031698A1 (en) * | 2007-07-06 | 2009-01-08 | Ccs Catalytic Combustion Systems Gmbh & Co. Kg | Device for protecting overheating of catalysts or components, comprises air vent, which is formed with materials of different melting temperatures or decomposition temperatures |
WO2011045390A1 (en) * | 2009-10-16 | 2011-04-21 | Commissariat à l'énergie atomique et aux énergies alternatives | Nuclear fuel assembly and nuclear reactor comprising such assemblies |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4036688A (en) * | 1975-04-09 | 1977-07-19 | The United States Of America As Represented By The United States Energy Research And Development Administration | Apparatus for controlling molten core debris |
GB1555208A (en) * | 1976-02-11 | 1979-11-07 | Westinghouse Electric Corp | Nuclear reactor core catcher |
US4643870A (en) * | 1985-11-21 | 1987-02-17 | The United States Of America As Represented By The United States Department Of Energy | Heat dissipating nuclear reactor |
DE3938111A1 (en) * | 1989-11-16 | 1990-06-07 | Walter Rietzscher | Safeguard arrangement for reactor core melt down emergency - having absorber tubes, absorber material containers and spacing bolts in reactor vessel bottom |
DE2843346C2 (en) * | 1977-10-10 | 1990-10-31 | United Kingdom Atomic Energy Authority, London, Gb | |
DE4032736A1 (en) * | 1990-10-15 | 1992-04-30 | Kernforschungsz Karlsruhe | Nuclear reactor foundation cooling system - for collecting and water cooling core melt |
-
1995
- 1995-01-18 DE DE19502540A patent/DE19502540A1/en not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4036688A (en) * | 1975-04-09 | 1977-07-19 | The United States Of America As Represented By The United States Energy Research And Development Administration | Apparatus for controlling molten core debris |
GB1555208A (en) * | 1976-02-11 | 1979-11-07 | Westinghouse Electric Corp | Nuclear reactor core catcher |
DE2843346C2 (en) * | 1977-10-10 | 1990-10-31 | United Kingdom Atomic Energy Authority, London, Gb | |
US4643870A (en) * | 1985-11-21 | 1987-02-17 | The United States Of America As Represented By The United States Department Of Energy | Heat dissipating nuclear reactor |
DE3938111A1 (en) * | 1989-11-16 | 1990-06-07 | Walter Rietzscher | Safeguard arrangement for reactor core melt down emergency - having absorber tubes, absorber material containers and spacing bolts in reactor vessel bottom |
DE4032736A1 (en) * | 1990-10-15 | 1992-04-30 | Kernforschungsz Karlsruhe | Nuclear reactor foundation cooling system - for collecting and water cooling core melt |
Non-Patent Citations (2)
Title |
---|
PERSHAGEN, Bengt: Light Water Reactor Safety. Pergamon Press, Oxford (u.a.), 1989, S. 257-290 und 424-436 * |
TONG, L.S.: Principles of Design Improvement for Light Water Reactors. Hemisphere Publishing Corporation, New York, (u.a.), 1988, S. 238-248 und 290-307 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007031698A1 (en) * | 2007-07-06 | 2009-01-08 | Ccs Catalytic Combustion Systems Gmbh & Co. Kg | Device for protecting overheating of catalysts or components, comprises air vent, which is formed with materials of different melting temperatures or decomposition temperatures |
WO2011045390A1 (en) * | 2009-10-16 | 2011-04-21 | Commissariat à l'énergie atomique et aux énergies alternatives | Nuclear fuel assembly and nuclear reactor comprising such assemblies |
FR2951578A1 (en) * | 2009-10-16 | 2011-04-22 | Commissariat Energie Atomique | ASSEMBLY OF NUCLEAR FUEL AND NUCLEAR REACTOR COMPRISING AT LEAST ONE SUCH ASSEMBLY |
CN102576571A (en) * | 2009-10-16 | 2012-07-11 | 法国原子能及替代能源委员会 | Nuclear fuel assembly and nuclear reactor comprising such assemblies |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
OP8 | Request for examination as to paragraph 44 patent law | ||
8130 | Withdrawal |