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Title: THE EXAMINATION AND EVALUATION OF IRRADIATED THORIUM-11 w/o URANIUM SPECIMENS

Technical Report ·
DOI:https://doi.org/10.2172/4253908· OSTI ID:4253908

Twelve irradiated specimens of thorium -11 wt.% U were examined. The specimens were fabricated by induction melting and casting in graphite and cold swaging to about 42% reduction in area. The irradiations were conducted in the MTR in capsules equipped with thermocouples. Six specimcns were irradiated to burnups ranging from 0.5 to 0.6 total at.% at average central corc temperatures ranging from 1070 to 1250 F. Three spccimens exbibited sevcre swelling or decrepitation and three appeared to be in relatively good condition. The density of these specimens decreased from 4.9 to 9.9%. The remaining six specimens were irradiated to burnups ranging from 0.9 to 1.5 total at.% at average central core temperatures ranging from 970 to 1100 F. These specimens were in relatively good condition, except for three that had swollen sevcrely at one end. Density decreases ranging from 2.4 to 3.8% were determined for these specimens. Swelling of all specimens appeared to be a linear function of burnup to the highest level studied (l.5 total at.%) and at temperatures below about 1100 F. Swelling increased significantly above 1100 F, even at burnups as low as 0.2 at.%. Fission-gas losses averaged about 0.5% for sound specimens after burnups of 1.2 to 3.3 total at.% at around l100 F. These losses were due to diffusion and recoil; cracked specimens exhibited higher losses, Metallographic examination of the specimens indicated that neither thc matrix material nor the fuel material was seriously affected by the irradiation. No evidence of corrosion by the NaK heat-transfer medium was present. (auth)

Research Organization:
Battelle Memorial Inst., Columbus, OH (United States)
DOE Contract Number:
W-7405-ENG-92
NSA Number:
NSA-13-013516
OSTI ID:
4253908
Report Number(s):
BMI-1334
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-59
Country of Publication:
United States
Language:
English