RADIATION STABILITY OF URANIUM MONONITRIDE

Technical Report · Fri Jun 28 04:00:00 EDT 1963

DOI:https://doi.org/10.2172/4157389· OSTI ID:4157389

Wullaert, R A; Lagedrost, J F; Bugl, J; Gates, J E

Bare and stainless steel-clad isostatically hot-pressed uranium mononitride pellets were irradiated to burnups up to 3.8 at.% of the uranium at temperatures as high as 615 deg C (surface) and 1260 deg C (center line) in NaK- filled capsules. The irradiation parameters were selected to permit an evaluation of the effect of both fuel burnup and hydrogen formation STAfrom the N/ sup 14/(n,p)C/sup 14/ reaction! on the stability of UN. Results of the irradiation indicated that hydrogen produced by the (n,p) reaction ( approximates 15 ppm) was not detrimental to the UN at these temperatures. Irradiated UN exhibited good dimensional stability, low fission gas release (<0.6 per cent), and 25 per cent increase in hardness. Only the most stringent temperatures and burnup conditions produced definite microstructural changes in the UN. Some grain growth occurred, and a white Second phase precipitated near the UN-cladding interface. There was no attack of the UN by NaK during irradiation. In general, uranium mononitride showed excellent radiation stability. (auth) Although much dosimetry data remain to be analyzed, a preliminary correlation of damage rates in different reactors is reported. Data from two positions in CP-5 appear to correlate well. Impact-test data from EBR-1 are smoothed in a novel way, and the results form a curve to which a straight-line approximation is made. The correlation is improved when an allowance for thermal neutrons please delete the above abstract---

• Research Organization: Battelle Memorial Inst., Columbus, Ohio
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-92
• NSA Number: NSA-18-000643
• OSTI ID: 4157389
• Report Number(s): BMI-1638; EURAEC-760
• Country of Publication: United States
• Language: English

Related Subjects

BURNUP
CAPSULES
CARBON 14
DEGASSING
EXPANSION
FISSION
FUEL CANS
GRAIN SIZE
HARDNESS
HIGH TEMPERATURE
HOT WORKING
HYDROGEN
IRRADIATION
LEAKS
METALLOGRAPHY
METALS, CERAMICS, AND OTHER MATERIALS
NEUTRON BEAMS
NITROGEN 14
NUCLEAR REACTIONS
PELLETS
PHASE DIAGRAMS
POTASSIUM ALLOYS
PRECIPITATION
PRESSURE
PROTONS
SODIUM ALLOYS
STABILITY
STAINLESS STEELS
SURFACES
URANIUM NITRIDES
VARIATIONS