AbstractAbstract
[en] Reactivity in thermal and epithermal reactors may be increased by inserting into these reactors at least one rod of a heavy element having high inelastic cross-section for high energy neutrons with energys above 1 MeV and low caputre cross-sections. The heavy element may be lead, bismuth, or compounds and mixtures of lead and bismuth. Such incrases may be used, for example, to reduce heavy water needs in the case of heavy water moderated reactors and enrichment needs in the case of light water reactors. (auth)
Primary Subject
Source
7 Aug 1980; 27 p; CA PATENT DOCUMENT 1081375/A/; Available from Micromedia Ltd., 165 Hotel de Ville, Hull, Quebec, Canada J8X 3X2; Assignee: Institute of Nuclear Energy Research, Atomic Energy Council, Republic of China.
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Patent
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ACTINIDES, BARYONS, BISMUTH COMPOUNDS, CHALCOGENIDES, ELEMENTARY PARTICLES, ELEMENTS, FERMIONS, HADRONS, HEAVY WATER MODERATED REACTORS, ISOTOPE ENRICHED MATERIALS, LEAD COMPOUNDS, METALS, NEUTRONS, NUCLEONS, OXIDES, OXYGEN COMPOUNDS, POWER REACTORS, PRESSURE TUBE REACTORS, REACTORS, THERMAL REACTORS, URANIUM, WATER COOLED REACTORS, WATER MODERATED REACTORS
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AbstractAbstract
[en] This invention concerns nuclear reactors in general and thermal and epithermal reactors in particular. Its object is to use heavy elements, such as Pb or Bi, to replace or add to the moderator at specific places in the reactor in order to obtain reactivity increases. These increases in reactivity can be achieved because the heavy elements can, in certain energy areas, have cross sections which are more advantageous from the nuclear angle for thermal and epithermal reactors than those of the moderators generally used. In particular, in the very high energy areas (above 1MeV) heavy elements have much greater elastic and non-elastic scattering cross sections, with a much greater energy thindown of the neutrons and have very much lower capture cross sections
[fr]
La presente invention concerne en general les reacteurs nucleaires et, en particulier, elle concerne les reacteurs thermiques et epithermiques. Elle a pour objet d'utiliser des elements lourds, tels que Pb ou Bi pour remplacer ou s'ajouter au moderateur a des emplacements specifiques dans le reacteur en vue d'obtenir des accroissements de reactivite. Ces accroissements de reactivite peuvent etre obtenus du fait que les elements lourds peuvent, en certaines zones d'energie, avoir des sections efficaces qui sont plus avantageuses nucleairement pour les reacteurs thermiques et epithermiques que celles des moderateurs generalement utilises. En particulier, dans les zones de tres haute energie (au-dessus de 1 MeV) les elements lourds ont des sections efficaces elastiques et non elastiques de diffusion beaucoup plus importantes, avec une degradation beaucoup plus importante de l'energie des neutrons et ont des sections efficaces de capture beaucoup plus faiblesOriginal Title
Procede d'accroissement de la reactivite dans des reacteurs nucleaires thermiques et epithermiques par l'utilisation d'elements lourds
Primary Subject
Source
21 Sep 1976; 22 p; FR PATENT DOCUMENT 2365184/A/; Available from Institut National de la Propriete Industrielle, Paris (France)
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Patent
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