THE EFFECT OF TEMPERATURE DURING IRRADIATION ON THE BEHAVIOUR OF HELIUM IN BERYLLIUM
Helium has been introduced into specimens of Brush Q.M.V. beryllium by irradiation with alpha particles in the M.I.T. cyclotron. During irradiation differert specimens have been held at a number of different temperatares from ambient to 740 deg C, respectively. The effect of the helium on the structure of the berylliuin has been studied by metallographic techniques. Helium concentrations as low as 0.05 vided the specimen received a sufficiently severe annealing treatment. Irradiation for 3.5 hr at 6OS deg C to a helium concentration of approx equal O.5 c/sup 3//cm/sup 3/ gave no structural effect, whereas irradiation at 740 deg C gave a marked effect. A helium concentration of approx equal 0.3 cm/sup 3//cm/sup 3/, giving no effect after irradiation at ambient temperatures, nor after an annealing treatment of 118 hours at 6OO deg C, gave an effect after 520 hr at this temperatare. Specimens irradiated at ambient temperatares have been annealed at the same elevated temperatare at which other specimens were irradiated with both time at temperature and gas concentrations kept to similar values. For each temperatare at which these comparisons were made no marked differenre in number or size of gas bubbles was detected. There was however an increased effect at grain boundaries in the case of irradiation at temperature. The results are discussed in terms of second phase particles acting as preferred points of gas bubble nucleation. The results suggest that the neutroninduced gas in the sheaths of beryllium-sheathed fuel elements will not cause catastrophic swelling at an operating temperatare of 600 deg C or lower. (auth)
- Research Organization:
- Atomic Energy of Canada Ltd. Chalk River Project, Chalk River, Ont.
- NSA Number:
- NSA-14-002777
- OSTI ID:
- 4228693
- Report Number(s):
- CRMet-864; AECL-898
- Country of Publication:
- Canada
- Language:
- English
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ELECTRON MICROSCOPE STUDIES OF IRRADIATED BERYLLIUM METAL
Gas retention in irradiated beryllium
Related Subjects
ANNEALING
BEHAVIOR
BERYLLIUM
BUBBLES
CANNING
CYCLOTRONS
DISTRIBUTION
EXPANSION
FUEL ELEMENTS
GASES
GRAIN BOUNDARIES
HELIUM
IRRADIATION
MEASURED VALUES
METALLOGRAPHY
METALS, CERAMICS, AND MATERIALS
NEUTRONS
NUCLEATE BOILING
PARTICLES
QUANTITY RATIO
RADIATION EFFECTS
TEMPERATURE
VOLUME