Corrosion evaluation of N reactor pressure tube 2455
N Reactor Zircaloy-2 pressure tube No. 2455 and its associated ASTM A234 steel nozzles were examined for corrosion and hydrogen content after approximately 680 days exposure in-reactor above zero power. The data are compared with data from a previous tube removed after approximately 300 days exposure. A visual examination of the ID and OD surfaces indicated adherent, dull black oxides on the pressure tube except for regions in the bottom third of the tube ID where numerous shallow (0.5 mil) scratches were found. These were due to sliding of fuel and fuel spacers through the tube during charge-discharge operations. Accelerated corrosion was not occurring at the scratched areas. Galling was observed at the location near the downstream end of the tube where a fuel rupture occurred; the galling was probably due to either the rupture or the rupture removal operation. Fretting corrosion of the tube at areas of contact between the pressure tube and the downstream spacers appeared to be similar to the fretting corrosion found in the previous tube. (auth)
- Research Organization:
- Battelle Pacific Northwest Labs., Richland, Wash. (USA)
- NSA Number:
- NSA-33-027978
- OSTI ID:
- 4074675
- Report Number(s):
- BNWL-CC--2101
- Country of Publication:
- United States
- Language:
- English
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