ML19064B403
| ML19064B403 | |
| Person / Time | |
|---|---|
| Site: | 99902028 |
| Issue date: | 02/15/2019 |
| From: | Lynnea Wilkins NRC/NRR/DLP/PLPB |
| To: | |
| Wilkins L, NRR/DLP/ 415-1377 | |
| Shared Package | |
| ML19043A746 -Pkg. | List: |
| References | |
| Download: ML19064B403 (6) | |
Text
Evaluation of Degraded and Nonconforming Conditions for ASME III Div.1 and B31.1 Structures, Systems, and Components A StructuredCorrectComplete Approach George Antaki, PE, Fellow ASME Chairman, ASME III Working Group Piping Design Member, ASME XI Task Group BeyondDesignBasis Member, ASME O&M Subcommittee on Piping Systems Becht Engineering Co.
5224 Woodside Executive Court Aiken SC 29803 Comments submitted to the NEINRC public meeting of Feb. 15, 2019 1
Scope: ASME III Div.1 and B31.1 SSCs ASME III and ASME B31.1 SSCs Pressure Boundary Active Mech. Eqt. Supports Vessels (III) Pumps (QME) Comp. Supports (III, Pumps (III) Valves (QME) B31.1, AISC, ACI)
Valves (III, B31.1) Active Restr. (QME) Core Supports (III)
Piping (III, B31.1)
Tanks (III) 2
This Presentation: Pressure Boundary Components ASME III and ASME B31.1 SSCs Pressure Boundary Vessels (III)
Pumps (III)
Valves (III, B31.1)
Piping (III, B31.1)
Tanks (III) 3 Grouping of Degraded or Nonconforming Conditions CrackLike Flaws Wall Thinning Weld flaw Fatigue Corrosion Erosion Both Corrosion Embrittlement Overload Loss or metallurgical, Op. or Postulated Load >
physical, mechanical Design properties Structural damage 4
Pr. Boundary: Degraded or Nonconforming Wall Thinning Corrosion Erosion Both 5
Wall Thinning
- 5. ASME III Ap. XIII (all components, was NB3200 pre2017) + 10CFR50.55(a)
- 6. ASME III Ap. XXVII (all components, was Ap. F* pre2017) + 10CFR50.55(a)
- 7. ASME XI Ap. U (piping, vessel/tank, moderate energy, pinhole)
- Acknowledged in current IMC0326.
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Pr. Boundary: Degraded or Nonconforming CrackLike Flaws Weld flaw Fatigue Corrosion 7
CrackLike
- 1. ASME XI IWA3000* (prequalified flaws) + 10CFR50.55(a)
- 2. ASME XI Ap. A (analytical evaluation of flaws)
- 3. ASME XI Ap. C (analytical evaluation of flaws in piping)
- 4. ASME XI Ap. H (analytical evaluation of flaws in piping, using FAD method)
- 5. ASME XI Ap. L (operating plants fatigue assessment)
- 6. ASME XI Ap. O (flaws in reactor vessel head penetrations)
- Acknowledged in current IMC0326.
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Pr. Boundary: Degraded or Nonconforming Overload Op. or Postulated Load >
Design Structural damage 9
Overload
- Overload: An actual or postulated load that exceeds the designbasis of the SSC, or that was not analyzed at the design stage.
- Examples:
- Accidental overpressure or accidental overtemperature
- Flowinduced vibration in service
- Locked snubber or physical interference
- Flood level exceeds design
- etc.
- Some overloads have been addressed through formal programs (seismic exceedance, flood exceedance, etc.)
- Other overloads are addressed adhoc (accidental overpressure, overtemp.)
- ASME XI Task Group BeyondDesignBasis has just started to look at overloads.
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Conclusions
- 1. It is essential to take a StructuredCorrectComplete approach to operability criteria for ASME SSCs. Such an approach is proposed here.
- 2. Methods and criteria already exist in the ASME Codes for the evaluation of several types of degraded and nonconforming conditions of pressure boundary components.
- 3. Other degraded and nonconforming conditions are addressed in an adhoc manner, as explained here. They need to be developed. ASME is taking first steps regarding overloads.
- 4. A similar structuredcorrectcomplete approach exists for active components, and support structures (not addressed here.)
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