Corrosion of Zircaloy-clad fuel rods in high-temperature PWRs: Measurement of waterside corrosion in North Anna Unit 1
- Westinghouse Electric Corp., Pittsburgh, PA (United States). Energy Systems Business Unit
Twenty-four peripheral rods and two interior rods from North Anna Unit 1, End-of-Cycle 7, were measured at poolside for waterside corrosion on four-cycle Region 6 assemblies F35 and F66, with rod average burnups of 60 GWD/MTU. Similar measurements were obtained on 24 two-cycle fuel rods from Region 8A assemblies H02 and H10 with average burnups of about 40 GWD/MTU. The Region 6 peripheral rods had been corrosion measured previously after three cycles, at 45 GWD/MTU average burnup. The four-cycle Region 6 fuel rods showed high corrosion, compared to only intermediate corrosion level after three cycles. The accelerated corrosion rate in the fourth cycle was accompanied by extensive laminar cracking and spalling of the oxide film in the thickest regions. The peak corrosion of the two-cycle region 8A rods was 32 {mu}m to 53 {mu}m, with some isolated incipient oxide spalling. In conjunction with the in-reactor corrosion measurements, extensive characterization tests plus long-term autoclave corrosion tests were performed on archive samples of the three major tubing lots represented in the North Anna measurements. The autoclave tests generally showed the same ordering of corrosion by tubing lot as in the reactor; the chief difference between the archive tubing samples was a lower tin content (1.38 percent) for the lot with the lowest corrosion rate compared with a higher tin content (1.58) for the lot with the highest corrosion rate. There was no indication in the autoclave tests of an accelerated rate of corrosion as observed in the reactor.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (United States); Westinghouse Electric Corp., Pittsburgh, PA (United States). Energy Systems Business Unit
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 10134425
- Report Number(s):
- EPRI-TR-100408-Tier1; ON: UN92010690
- Resource Relation:
- Other Information: PBD: Mar 1992
- Country of Publication:
- United States
- Language:
- English
Similar Records
Corrosion behavior of Zircaloy-4 cladding with varying tin content in high-temperature pressurized water reactors
In-reactor corrosion performance of ZIRLO{trademark}4 and Zircaloy-4