Preheat and interpass temperature control for the welding of low-alloy steel for use in fuel reprocessing plants and in plutonium processing and fuel fabrication plants

The regulatory guide provides that weld fabrication for low-alloy steel components important to safety should comply with acceptable fabrication requirements and should be performed by qualified welders and welding procedures in accordance with the requirements of Section IX of the ASME Code supplemented by the following: 1. The procedure qualification should require that: a. A minimum preheat and a maximum interpass temperature be specified. b. The welding procedure be qualified at the minimum preheat temperature. 2. For production welds, the preheat temperature should be maintained until a postweld heat treatment has been performed. 3. Production welding should be monitored to verify that the limits on preheat and interpass temperatures are maintained. 4. In the event that regulatory positions C.1, C.2, and C.3 above are not met, the weld is subject to rejection. However, the soundness of the weld may be verified by an acceptable examination procedure. (U.S.)