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Title: IN-REACTOR MONITORING OF ZIRCALOY-2 PRTR PRESSURE TUBES, PART III. JULY 1963-NOVEMBER 1963

Technical Report ·
OSTI ID:4043236

From July 1962, through November 1963, all Zircaloy-2 pressure tubes in all 85 process channels of the PRTR were inspected at least once, and a few were inspected several times. These inspections showed that approximately 1700 new fretted areas formed in the pressure tubes. There are now approximately 3200 fretted areas in aH tubes in the PRTR. An increase in fretted areas associated with the fuel element end bracket spacers appears to be roughly proportional to the number of times fuel elements were charged irto each pressure tube. During this reporting period, there was a significant increase in the number of fretted areas associated with single fuel rod wire wraps as compared to the number associated with end bracket spacers. There was no observable fretting corrosion associated with the circumferential fuel bundle bands on the Al-Pu or mixed oxide type fuel elements. Enlarging the contact area of the end bracket spacers from approximates 1.5 x 4 x 1/2 in.) significantly reduced the severity of tube wall penetration by fretting. In no case did penetrations, associated with enlarged pads, exceed 0.025 mm (0.001 in.). There is some reason to believe that end bracket spacer pad enlargement also caused a decrease in severity of fretting associated with single rod spiral wire wraps but apparently had no effect on incidence. Five pressure tubes were discharged during this reporting period. Two of these five were discharged because of suspected defects with depths of approximates 1/2 mm ( approximates 0.020 in.) or greater. (auth)

Research Organization:
General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
DOE Contract Number:
AT(45-1)-1350
NSA Number:
NSA-18-019426
OSTI ID:
4043236
Report Number(s):
HW-80158
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-64
Country of Publication:
United States
Language:
English