Release of tritium from boron carbide
Description
The aim of the study is to examine under practice-relevant conditions the release of tritium produced in a 10B(n,2dt) reaction in boron carbide (= material of control rods in reactors). Besides neutron-exposed material, material implanted with high-energy tritons was also used in the investigation. The diffusion factors were determined with the help of various models for pulverized and sintered boron carbide. The diffusion factor is clearly affected by neutron fluence above 1016 neutrons/cm2. It decreases within the range of 1016-1020 n/cm2, the difference from unirradiated material for a temperature of 900deg C amounting to three orders of magnitude. It apparently increases when the neutron fluence is greater than 5x1020 n/cm2, presumably as a result of embrittlement due to irradiation defects. Unirradiated oxidized boron carbide samples exhibit a retarded release of tritium, due to its low mobility in B2O3. (RB)
Availability note (English)
Available from the library of Technische Hochschule Darmstadt (Germany, F.R.).Abstract (German)
Ziel der Arbeit ist, die Abgabe von in einer 10B(n,2dt)-Reaktion in Borcarbid (= Material der Steuerstaebe im Reaktor) erzeugtem Tritium unter praxisrelevanten Bedingungen zu untersuchen. Dabei kam neben neutronenbestrahltem Material auch mit hochenergetischen Tritonen implantiertes Material zur Anwendung. Die Diffusionskoeffizienten wurden unter Anwendung verschiedener Modelle bei pulverfoermigem und gesintertem Borcarbid bestimmt. Der Diffusionskoeffizient ist deutlich von der Neutronenfluens oberhalb 1016 Neutronen/cm2 beeinflusst. Er nimmt ab im Bereich 1016-1020 n/cm2, wobei der Unterschied zu unbestrahltem Material fuer eine Temperatur von 900deg C drei Groessenordnungen betraegt. Bei einer Neutronenfluenz groesser 5x1020 n/cm2 nimmt er scheinbar zu, vermutlich durch strahlendefektbedingte Versproedung. Oxidierte unbestrahlte Borcarbidproben zeigen eine verlangsamte T-Abgabe, bedingt durch geringere T-Beweglichkeit im B2O3. (RB)Additional details
Additional titles
- Original title (German)
- Abgabe von Tritium aus Borcarbid
Publishing Information
- Imprint Pagination
- 106 p.
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 21009627
- Subject category
- S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY; S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Thesis, Non-conventional Literature
- Descriptors DEI
- BETA DETECTION; BORON CARBIDES; BORON OXIDES; CRYSTAL DEFECTS; CRYSTALS; DEGASSING; DIFFUSION; DOPED MATERIALS; EMBRITTLEMENT; GRAIN SIZE; ION IMPLANTATION; ISOTHERMS; MATHEMATICAL MODELS; NEUTRON FLUENCE; NEUTRON REACTIONS; OXIDATION; PHYSICAL RADIATION EFFECTS; POWDERS; REACTION KINETICS; SINTERED MATERIALS; TEMPERATURE DEPENDENCE; TRITIUM
- Descriptors DEC
- BARYON REACTIONS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BORON COMPOUNDS; CARBIDES; CARBON COMPOUNDS; CHALCOGENIDES; CHARGED PARTICLE DETECTION; CHEMICAL REACTIONS; CRYSTAL STRUCTURE; DETECTION; HADRON REACTIONS; HYDROGEN ISOTOPES; ISOTOPES; KINETICS; LIGHT NUCLEI; MATERIALS; MICROSTRUCTURE; NUCLEAR REACTIONS; NUCLEI; NUCLEON REACTIONS; ODD-EVEN NUCLEI; OXIDES; OXYGEN COMPOUNDS; RADIATION DETECTION; RADIATION EFFECTS; RADIOISOTOPES; SIZE; YEARS LIVING RADIOISOTOPES