Controlled, all-position, butterbead-temperbead welding technique for nuclear repairs

Journal Article · Sat Feb 01 00:00:00 EST 1986 · Weld. J. (Miami); (United States)

OSTI ID:6052114

Clark, J N; Lambert, J A

Sections III and XI of the ASME boiler and pressure vessel code describe a half-bead temper repair welding technique specifically designed for in-service BWR and PWR repair applications without postweld heat treatment. The method relies on deposition of two layers of weld beads. Prior to deposition of the second layer, half the first layer is ground away. As a result, the first layer HAZ is tempered or retransformed by the second layer heat input. It is on the basis of this tempering that a concession is granted to omit postweld heat treatment. The grinding stage is difficult to control, time consuming, and can involve long exposure of personnel to a radioactive environment. Consequently, there has been pressure to find a viable alternative to the half-bead technique. Much interest has been shown in the butterbead-temperbead technique, which is essentially the CEGB two-layer HAZ refinement technique. This does not require grinding of the first layer and achieves HAZ retransformation by increasing the heat input of the second layer. The elimination of the grinding stage considerably reduces repair time and, consequently, radiation exposure. The method has now been included as an acceptable alternative to the half-bead technique in section XI of the ASME code. The CEGB method has been used successfully in the U.K. power industry, mainly for prevention of stress relief cracking, but also to improve HAZ toughness for low temperature service. Two-layer HAZ refinement is achieved by retransformation of the first layer HAZ by the thermal field of the second layer.

• Research Organization: CEGB, Marchwood Eng. Labs., Marchwood, Southampton
• OSTI ID: 6052114
• Journal Information: Weld. J. (Miami); (United States), Vol. 65:2
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
BWR TYPE REACTORS
REACTOR COMPONENTS
PWR TYPE REACTORS
REPAIR
WELDING
GRINDING
HEAT AFFECTED ZONE
PERSONNEL DOSIMETRY
TEMPERING
COMMINUTION
DOSIMETRY
FABRICATION
HEAT TREATMENTS
JOINING
MACHINING
REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZONES
210100* - Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
210200 - Power Reactors
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Light-Water Moderated
Nonboiling Water Cooled