Severe Pitting Attack of Pile Process Tubes and Slugs

Technical Report · Tue Jun 30 04:00:00 EDT 1953

DOI:https://doi.org/10.2172/2377955· OSTI ID:2377955

Lewis, M. ^[1]; Rohrbacher, R. A. ^[1]

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1. Hanford Site (HNF), Richland, WA (United States)

The severe pitting attack of pile process tubes and slug jackets that occurred at HAPO during the summer of 1952 was investigated. Several process tubes that were removed from the piles because of water leakage or suspected damage from ruptured slugs were found to be severely pitted on the inside with penetration of the tube wall occurring where leakage was evident. At about the same time a type of surface attack, not previously observed, was found on some slugs discharged from F Pile. In some instances, both the slugs and tubes from the same channel showed this type of attack. Incidents of attack in process tubes in the Flow Laboratory were found to be similar to the in-pile phenomenon. The attack on both the tubes and slugs in the Flow Laboratory occurred in the vicinity of obstructions to the flow of water, took place in nine to twelve days, and appeared to be of a mechanical nature. The occurrence of this pitting attack, observed in the piles and in the Flow Laboratory appears to require several conditions, such as; water temperature above 60 C, water velocity above 17 feet per second, and flow irregularities in the annulus. These flow irregularities occur at slug junctions and at misaligned slugs, and are even more serious if loose particulate matter in the tube should become lodged in the annulus. Experimental evidence indicates that the observed attack is inhibited by the presence of dichromate ions in the cooling water.

• Research Organization: Hanford Site (HNF), Richland, WA (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-31-109-ENG-52
• OSTI ID: 2377955
• Report Number(s): HW--29132; DE91012976
• Country of Publication: United States
• Language: English

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