TMI-2 instrument nozzle examinations at Argonne National Laboratory
Six of the 14 instrument-penetration-tube nozzles removed from the lower head of TMI-2 were examined to identify damage mechanisms, provide insight to the fuel relocation scenario, and provide input data to the margin-to-failure analysis. Visual inspection, gamma scanning, metallography, microhardness measurements, and scanning electron microscopy were used to obtain the desired information. The results showed varying degrees of damage to the lower head nozzles, from {approx}50% melt-off to no damage at all to near-neighbor nozzles. The elevations of nozzle damage suggested that the lower elevations (near the lower head) were protected from molten fuel, apparently by an insulating layer of fuel debris. The pattern of nozzle damage was consistent with fuel movement toward the hot-spot location identified in the vessel wall. Evidence was found for the existence of a significant quantity of control assembly debris on the lower head before the massive relocation of fuel occurred.
- Research Organization:
- Argonne National Lab., IL (United States)
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10188804
- Report Number(s):
- ANL/ET/CP-79615; CONF-9310111-2; ON: DE94001327; TRN: 94:000039
- Resource Relation:
- Conference: Conference and open forum for the presentation of significant results: achievements of the OECD Three Mile Island vessel investigation project,Boston, MA (United States),20-22 Oct 1993; Other Information: PBD: Sep 1993
- Country of Publication:
- United States
- Language:
- English
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