CH320931A - Element with fissile material for nuclear reactors - Google Patents

Element with fissile material for nuclear reactors

Info

Publication number
CH320931A
CH320931A CH320931DA CH320931A CH 320931 A CH320931 A CH 320931A CH 320931D A CH320931D A CH 320931DA CH 320931 A CH320931 A CH 320931A
Authority
CH
Switzerland
Prior art keywords
fissile material
shell
fissile
nuclear reactors
percent
Prior art date
Application number
Other languages
German (de)
Inventor
Haelg Walter Dr Phys
Zuenti Werner Dr Phys
Original Assignee
Bbc Brown Boveri & Cie
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 Bbc Brown Boveri & Cie filed Critical Bbc Brown Boveri & Cie
Publication of CH320931A publication Critical patent/CH320931A/en

Links

Classifications

    • GPHYSICS
    • G21NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21CNUCLEAR REACTORS
    • G21C3/00Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
    • G21C3/02Fuel elements
    • G21C3/04Constructional details
    • G21C3/16Details of the construction within the casing
    • G21C3/20Details 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
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00Energy generation of nuclear origin
    • Y02E30/30Nuclear 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)

Description

  

  Element mit spaltbarem Material für Kernreaktoren    Es ist eine Bauart für Kernreaktoren  bekannt, in welcher Stäbe oder Rohre von  spaltbarem Material (z. B. Uran) von einem  Moderator (z. B. schweres Wasser) umgeben  sind. Damit die bei den Kernspaltungen ent  stehenden radioaktiven Substanzen nicht in  den Moderator entweichen können, sind die  Stäbe oder Rohre mit je einer Hülle aus ge  eignetem Material (z. B. Aluminium) ver  sehen.  



  Diese Stäbe oder Rohre zeigen nun beim  Betrieb des Reaktors infolge der Temperatur  einflüsse mehr oder weniger starke Formände  rungen. Dadurch werden Hüllen, welche an  fänglich das spaltbare Material fest umschlos  sen, lose. Die Folge ist eine Verschlechterung  des Wärmeüberganges vom spaltbaren Ma  terial in die Hülle. Befinden sich innerhalb  der Hülle Spuren von Sauerstoff, so tritt eine  Oxydation des spaltbaren Materials auf, welche  den Wärmeübergang noch weiter erschwert.  Eine Folge von schlechtem Wärmeübergang  sind unzulässig grosse Temperaturdifferenzen  im spaltbaren Material, welche zu mechani  schen Schäden führen können.  



  Dieser Nachteil wird erfindungsgemäss da  durch vermieden, dass zwischen dem spaltbaren  Material und der Hülle ein Zwischenmedium  vorgesehen wird, welches bei der Betriebstem  peratur des Kernreaktors flüssig ist und wel  ches einen guten Wärmeübergang zwischen  dem spaltbaren Material und der Hülle be  wirkt.    Ein für den vorgesehenen Zweck geeignetes       Mediiun    soll einen kleinen Absorptionsquer  schnitt für Neutronen     aufweisen,    darf bei den  in Frage kommenden Temperaturen weder  mit dem spaltbaren Material noch mit dem  Material der Hülle reagieren und soll auch  durch die Spaltprodukte nicht angegriffen  werden. Wird ein Medium gewählt, welches  bei Zimmertemperatur fest ist, so soll die  Volumenänderung beim Schmelzen möglichst  gering sein.  



  Als geeignetes Zwischenmedium hat sich  eine Legierung von 44,5 Gewichtsprozenten  Blei und 55,5 Gewichtsprozenten Wismut er  wiesen, deren Schmelzpunkt bei 125  C liegt.



  Element with fissile material for nuclear reactors A design for nuclear reactors is known in which rods or tubes of fissile material (e.g. uranium) are surrounded by a moderator (e.g. heavy water). So that the radioactive substances produced during nuclear fission cannot escape into the moderator, the rods or tubes are each provided with a cover made of a suitable material (e.g. aluminum).



  These rods or tubes now show more or less strong changes in shape during operation of the reactor as a result of the temperature influences. As a result, casings which initially firmly enclose the fissile material are loose. The result is a deterioration in the heat transfer from the fissile material into the shell. If there are traces of oxygen within the shell, oxidation of the fissile material occurs, which makes the heat transfer even more difficult. One consequence of poor heat transfer are inadmissibly large temperature differences in the fissile material, which can lead to mechanical damage.



  According to the invention, this disadvantage is avoided by providing an intermediate medium between the fissile material and the shell, which is liquid at the operating temperature of the nuclear reactor and which ensures good heat transfer between the fissile material and the shell. A medium suitable for the intended purpose should have a small absorption cross-section for neutrons, must not react with the fissile material or the material of the shell at the temperatures in question and should not be attacked by the fission products. If a medium is chosen that is solid at room temperature, the change in volume during melting should be as small as possible.



  An alloy of 44.5 percent by weight lead and 55.5 percent by weight bismuth, with a melting point of 125 ° C., has proven to be a suitable intermediate medium.

 

Claims (1)

PATENTANSPRUCH Element mit spaltbarem Material für Kern reaktoren, bei welchem das spaltbare Material von einer Hülle umgeben ist, dadurch gekenn zeichnet, dass sich zwischen dem spaltbaren Material und der Hülle ein Zwischenmedium befindet, welches bei der Betriebstemperatur des Reaktors flüssig ist und einen guten Wärmeübergang zwischen dem spaltbaren Ma terial und der Hülle bewirkt. UNTERANSPRUCH Element nach Patentanspruch, gekenn zeichnet durch eine Legierung von 44,5 Ge wichtsprozenten Blei und 55,5 Gewichtspro zenten Wismut als Zwischenmedium. PATENT CLAIM Element with fissile material for core reactors, in which the fissile material is surrounded by a shell, characterized in that there is an intermediate medium between the fissile material and the shell, which is liquid at the operating temperature of the reactor and a good heat transfer between causes the fissile Ma material and the shell. SUBSTANTIAL CLAIM Element according to claim, characterized by an alloy of 44.5 percent by weight lead and 55.5 percent by weight bismuth as an intermediate medium.
CH320931D 1954-08-21 1954-08-21 Element with fissile material for nuclear reactors CH320931A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH320931T 1954-08-21

Publications (1)

Publication Number Publication Date
CH320931A true CH320931A (en) 1957-04-15

Family

ID=4498190

Family Applications (1)

Application Number Title Priority Date Filing Date
CH320931D CH320931A (en) 1954-08-21 1954-08-21 Element with fissile material for nuclear reactors

Country Status (1)

Country Link
CH (1) CH320931A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020185502A3 (en) * 2019-03-07 2020-10-22 Westinghouse Electric Company Llc Self-healing liquid pellet-cladding gap heat transfer filler

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020185502A3 (en) * 2019-03-07 2020-10-22 Westinghouse Electric Company Llc Self-healing liquid pellet-cladding gap heat transfer filler
JP2022523582A (en) * 2019-03-07 2022-04-25 ウェスティングハウス エレクトリック カンパニー エルエルシー Self-healing liquid pellet-coating gap heat transfer filler
JP2025020202A (en) * 2019-03-07 2025-02-12 ウェスティングハウス エレクトリック カンパニー エルエルシー Self-healing liquid pellet-coated gap heat transfer filler
US12412672B2 (en) 2019-03-07 2025-09-09 Westinghouse Electric Company Llc Fuel rod having heat transfer liquid filling the gap between fuel pellets and cladding tube

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