ML050760401
| ML050760401 | |
| Person / Time | |
|---|---|
| Site: | Boiling Water Reactor Owners Group |
| Issue date: | 03/16/2005 |
| From: | Bo Pham Office of Nuclear Reactor Regulation |
| To: | |
| Pham B M/NRR/DLPM/PD-2,415-8450 | |
| Shared Package | |
| ML050960591 | List: |
| References | |
| Download: ML050760401 (16) | |
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BWROG PRESSURE-TEMPERATURE CURVE FRACTURE MECHANICS METHODOLOGY Presentation to NRC March 16, 2005 White Flint TONY BROWNING (NMC-Duane Arnold)
BWROG Pressure-Temperature Curve Committee Chairman March 16, 2005 BWROG-NRC Pre-LTR Meeting I
BWROG Pressure-Temperature Curves PRESENTATION OBJECTIVES
- Solicit NRC observations.
- Obtain estimates of NRC review resources and schedule.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 2
BWROG Pressure-Temperature Curves PRESENTATION OUTLINE
- Background
- Concept
- Purpose
- Scope
- Supporting Bases
- Relationship with Other Industry Activities
- Coordination with Other Industry Organizations
- Issues Potentially Affecting NRC Acceptance
- Completeness of LTR Submittals
- Improved Industry Efficiency
- Planned LTR Submittal Schedule March 16, 2005 BWROG-NRC Pre-LTR Meeting 3
BWROG Pressure-Temperature Curves BACKGROUND
- Tech Specs (TS) currently include limiting conditions for operation that establishes Pressure-Temperature (PT) limits for the reactor coolant system.
- During startup and shutdown, the rates of PT changes are limited so that maximum specified heat up and cool down rates are consistent with design assumptions and satisfy operating limits that provide a wide margin of safety for brittle-fracture criteria for the reactor vessel.
- The PT limits are periodically modified as the reactor vessel material toughness decreases as a result of material embrittlement caused by neutron irradiation during plant operation.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 4
BWROG Pressure-Temperature Curves CONCEPT
- Licensees must submit a license amendment to update reactor pressure vessel Pressure-Temperature Curves (PTC) located in TSs.
- GL 96-03 allows license amendments to relocate PTCs from plant TSs to a licensee-controlled document provided that:
The PTC methodology is approved by the NRC, A report (such as a PT Limits Report-PTLR) is developed to contain the PTCs, and TSs are modified to note the relocation.
- Most BWRs employ either General Electric (GE) or Structural Integrity Associates (SIA) PTC fracture mechanics methodology.
- BWROG plans to submit both GE and SIA PTC fracture mechanics methodology for generic NRC approval via separate Licensing Topical Reports (LTR).
- These LTRs will allow "plug and play" with NRC-approved vessel fluence methods currently used by licensees.
March 26, 2005 BWROG-NRC Pre-LTR Meeting 5
BWROG Pressure-Temperature Curves PURPOSE Develop LTRs for NRC submittal of both GE and SIA PTC fracture mechanics methodologies that, if approved by the NRC, can be then referenced by BWR licensees (in concert with NRC-approved vessel fluence methods) to allow PTCs (and limits) to be relocated from plant TSs to a PTLR, a licensee-controlled document.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 6
BWROG Pressure-Temperature Curves SCOPE Develop and document separate GE and SIA PTC fracture mechanics methodologies and submit to the NRC for review/approval via separate LTRs.
GE LTR will have proprietary and non-proprietary versions.
SIA LTR will be non-proprietary.
- In accordance with GL 96-03, develop a BWR model for a license amendment request to adopt GL 96-03, including a template for the PTLR, and provide these for NRC review at the time of LTR methodology submittals.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 7
BWROG Pressure-Temperature Curves SUPPORTING BASES
- The BWROG effort will take advantage of industry lessons learned with GL 96-03, in addition to previous BWR licensee PTC amendment request experience, including past Staff Requests for Additional Information (RAI).
- The LTRs will be similar to PWR LTRs previously approved by the NRC (e.g., WCAP-14040).
March 16, 2005 BWROG-NRC Pre-LTR Meeting 8
BWROG Pressure-Temperature Curves RELATIONSHIP TO OTHER INDUSTRY ACTIVITIES Although not directly related, there may be interfaces related to vessel materials issues such as the Integrated Surveillance Program (ISP).
March 16, 2005 BWROG-NRC Pre-LTR Meeting 9
BWROG Pressure-Temperature Curves ISSUES THAT COULD AFFECT NRC ACCEPTANCE The BWROG does not foresee any issues that could negatively affect NRC acceptance based on previous NRC and industry experiences with PTC submittals and GL 96-03.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 10
BWROG Pressure-Temperature Curves COMPLETENESS OF LTRs The content of planned LTRs will be based on existing industry experience with individual licensee TS PTC amendment submittals, sufficient for thorough Staff review and a basis for the issuance of Safety Evaluation Reports (SER).
March 16, 2005 BWROG-NRC Pre-LTR Meeting I1I
BWROG Pressure-Temperature Curves IMPROVED INDUSTRY EFFICIENCY
- As stated in GL 96-03, processing amendment requests to relocate PTCs outside TSs to a licensee-controlled document will allow more efficient utility maintenance of PTCs at significantly reduced costs to licensees.
- With NRC approval of these generic PTC fracture mechanics methodology LTRs, licensees can seek NRC approval to adopt GL 96-03 by merely referencing the pre-approved methods saving NRC valuable resources in individual plant reviews.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 12
BWROG Pressure-Temperature Curves PLANNED LTR SUBMITTALS
- The BWROG will be requesting NRC review/acceptance by May 2006.
What is the anticipated impact (if any) on NRC schedule of planned NRC Rulemaking on PT limits?
March 16, 2005 BWROG-NRC Pre-LTR Meeting 13
BWROG Pressure-Temperature Curves PRELIMINARY LTR OUTLINE (Requirements for methodology submittals per GL 96-03)
- 1. Fluence Methodology: Fluence methodology will not be included in the PTC fracture mechanics LTRs. Licensees must reference the fluence methodology they currently have adopted when submitting their GL 96-03 license amendment request.
- 2.
RPV Surveillance Program
Description:
The LTRs will cite the ISP as all BWRs are participating.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 14
BWROG Pressure-Temperature Curves PRELIMINARY LTR OUTLINE (Requirements for methodology submittals per GL 96-03)
- 6. Minimum Temperature Requirements of I OCFR50: Will be covered in the LTRs.
- 7. Test Capsule Removal: The LTRs will address this. ISPs control all capsules, including the definition/specification of values to be used on plants per BWRVIP-135 Databook and implementation methodology per BWRVIP-102.
March 16, 2005 BWROG-NRC Pre-LTR Meeting 15
BWROG Pressure-Temperature Curves NRC OBSERVATIONS
- NRC observations?
- Estimate of NRC review resources?
- Estimate of NRC review schedule?
March 16, 2005 BWROG-NRC Pre-LTR Meeting 16