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Title: The effects of vent-notch area on bulging and thinning during the clad vent test closure-weld operation

Abstract

The internal gas pressure during clad vent set (CVS) welding is vented through aligned vent notches in each cup. For Galileo, Ulysses, and most of Cassini CVS production, the vent-notch dimensional requirements for both cups were as follows: (1) vent-notch depth, 0.15/0.20 mm; (2) vent-notch width, 0.25/0.35 nun; (3) bottom of vent-notch comers, sharp to full radius; (4) top of vent-notch edge, 0.05 mm maximum break; and (5) maximum variation between vent notch and grit-blasted triangle centerlines, 3{degrees}. During the fuel encapsulation operation (with {sup 238}PuO{sub 2} fuel pellets) at Los Alamos National Laboratory (LANL), excessive bulges or blowouts at the CVS closure-weld tie-in location occurred with 11.8% (27 out of 229) of the flight-quality welds made with the aforementioned standard vent-notch dimensions. These bulges and blowouts are primarily the result of inadequate venting of the increased gas pressure during the thermal cycle of the closure-weld operation. Proper venting is dependent mostly upon the weld parameters and the total vent-notch area. Because of the increased incidence of bulges/blowouts in the {sup 238}PuO{sub 2}-fueled CVS units, LANL personnel requested that consideration be given to increasing the vent-notch size to minimize further the loss of CVS hardware and the potential loss ofmore » {sup 238}PuO{sub 2} pellets. Thus, increasing further the production yield of the closure-weld operation would avoid potentially severe schedule delays.« less

Authors:
Publication Date:
Research Org.:
Oak Ridge Y-12 Plant, TN (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
434424
Report Number(s):
Y/DV-1425
ON: DE97002831; TRN: 97:001136
DOE Contract Number:  
AC05-96OR22464
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Sep 1996
Country of Publication:
United States
Language:
English
Subject:
07 ISOTOPE AND RADIATION SOURCE TECHNOLOGY; FUEL CANS; WELDING; FAILURES; VENTS; OPTIMIZATION; JACKETS; NESDPS Office of Nuclear Energy Space and Defense Power Systems

Citation Formats

Ulrich, G.B. The effects of vent-notch area on bulging and thinning during the clad vent test closure-weld operation. United States: N. p., 1996. Web. doi:10.2172/434424.
Ulrich, G.B. The effects of vent-notch area on bulging and thinning during the clad vent test closure-weld operation. United States. doi:10.2172/434424.
Ulrich, G.B. Sun . "The effects of vent-notch area on bulging and thinning during the clad vent test closure-weld operation". United States. doi:10.2172/434424. https://www.osti.gov/servlets/purl/434424.
@article{osti_434424,
title = {The effects of vent-notch area on bulging and thinning during the clad vent test closure-weld operation},
author = {Ulrich, G.B.},
abstractNote = {The internal gas pressure during clad vent set (CVS) welding is vented through aligned vent notches in each cup. For Galileo, Ulysses, and most of Cassini CVS production, the vent-notch dimensional requirements for both cups were as follows: (1) vent-notch depth, 0.15/0.20 mm; (2) vent-notch width, 0.25/0.35 nun; (3) bottom of vent-notch comers, sharp to full radius; (4) top of vent-notch edge, 0.05 mm maximum break; and (5) maximum variation between vent notch and grit-blasted triangle centerlines, 3{degrees}. During the fuel encapsulation operation (with {sup 238}PuO{sub 2} fuel pellets) at Los Alamos National Laboratory (LANL), excessive bulges or blowouts at the CVS closure-weld tie-in location occurred with 11.8% (27 out of 229) of the flight-quality welds made with the aforementioned standard vent-notch dimensions. These bulges and blowouts are primarily the result of inadequate venting of the increased gas pressure during the thermal cycle of the closure-weld operation. Proper venting is dependent mostly upon the weld parameters and the total vent-notch area. Because of the increased incidence of bulges/blowouts in the {sup 238}PuO{sub 2}-fueled CVS units, LANL personnel requested that consideration be given to increasing the vent-notch size to minimize further the loss of CVS hardware and the potential loss of {sup 238}PuO{sub 2} pellets. Thus, increasing further the production yield of the closure-weld operation would avoid potentially severe schedule delays.},
doi = {10.2172/434424},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Sep 01 00:00:00 EDT 1996},
month = {Sun Sep 01 00:00:00 EDT 1996}
}

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