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Status Report: Welding Task
GroupReport to NESCC – 28 March
2013Tom Siewert – NIST
Objectives• Review the welding standards (ASME,
AWS, etc.) used in nuclear construction
• Look for inconsistencies between them, and areas where they lag behind current technology
• Make recommendations to the standards bodies that would streamline the construction of safer nuclear plants (value to stakeholders)
Team (~50 Participants)• About ½ representing
industry (mostly chairs of AWS technical subcommittees)• About ¼ representing
associations• About ¼ representing
government
Timeline• First meeting – November, 2011
– face to face• Nine meetings since then (8
teleconferences and 1 face to face
• Final report – Fall, 2013 (target)
Structure• WTG – to oversee progress and evaluate
recommendations drafted by working groups• Working Groups – by technical discipline
o Welding Technology• Fabrication Techniques – Mark Holland – Interim
Chair• Rebar Issues – Mike Gass – Vice Chair
o Inspection Technologyo Personnel/Qualification Issues – Jeff Fluckiger –
Chairo Material Issues
• Heat Treatment – Phil Flenner -- Chair
Representative Technical Issues
• Waveform-based Power Sources – new electronics permit alternate pulse shapes that may fall outside traditional procedures (WPS)
• Phased-array Ultrasonic Inspection – new capabilities may speed inspections and find previously hidden imperfections
• Digital X-ray Imaging Technology – replacing film technology can speed inspections and lower consumable costs -- May also allow CT imaging slides
• Visual Inspection – technique may have advanced (NP 5380)
• Personnel Certification - increasingly being required, but PE in welding had been discontinued
Top 5 Needs (of end users)
o Avoiding senseless requalification of welding procedures. Why do we need to requalify again and again to prove what we already know? The available prequalified welding procedures distributed by AWS cover only a fraction of what is needed.
o Keeping individuals standards aligned with each other (especially those developed by different organizations). While AWS B2 requirements are currently well aligned with those of ASME Section IX, others are not.
o Make repair decisions based on fitness-for-service assessments. Currently many repair decisions are made on workmanship standards, where unnecessary repairs often introduce additional damage that can be the source for later failures during service. Switching to repair decisions based on fracture mechanics would mean that only necessary repairs are made.
Near-term Actions• Expand database with members
qualifications• Fill empty slots in working group structures• Get top 5 needs from customers (end-users
of the standards)• Assign needs to appropriate working group.
