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Title: SNAP I--DYNAMIC MERCURY LOOP TESTS OF SELECTED MATERIALS. Period covered : January 1957-June 1959

Technical Report ·
DOI:https://doi.org/10.2172/4131227· OSTI ID:4131227

Six dynamic boiling-mercury loops were tested in connection with the SNAP-I program. The loops were Croloy-5 Si, Croloy-5 Ti, Carpenter 20 Nb, Types 347 and 446 stainless steel and a Type 347 stainless-steel-clad niobium boiler coil inserted into the Type 347 stainless-steel loop. Operation of the Croloy-5 Si loop was discontinued after about 86 hr because the heaters bured out. Extensive general corrosion which penetrated as much as 3.5 mils occurred during this time. The boiler-outlet leg of the Croloy-5 Ti loop ruptured after l66 hr of operation. Again, extensive general corrosion occurred with up to 5 mils penetration. The Carpenter 20 Nb loop was never operated at design conditions. It failed after a short time when arcing from the heater to the coil burned through the tubing. The Type 347 stainless-steel loop failed after 326 hr when the outlet leg of the boiler coil ruptured. Extensive depletion of nickel with penetrations up to 20 mils was found in the condenser. The Type 446 stainless- steel loop did not fail. Its operation was discontinued after 141 hr because of multiple leaks. Numerous transgranular cracks were found in the boiler coil, but the origin of these cracks was problematical. The remainder of this loop was apparently unaffected. The niobium coil ruptured after 50 hr of operation. The failure was probably caused by atmospheric oxygen, which contacted the niobium when the Type 347 stainless-steel cladding failed. Successful operating experiences involving two-phase mercury flow and totalling more than 500 hr were obtained using Type 316 stainlesssteel tubiug. Operating conditions for the mercury working fluid at the inlet of this tubing were 200 psia and 1100 to 1350 deg F. (auth)

Research Organization:
Martin Co. Nuclear Div., Baltimore
Sponsoring Organization:
USDOE
DOE Contract Number:
AT(30-3)-217
NSA Number:
NSA-15-000564
OSTI ID:
4131227
Report Number(s):
MND-P-2128
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-61
Country of Publication:
United States
Language:
English