ML18142A249
ML18142A249 | |
Person / Time | |
---|---|
Site: | 99902028 |
Issue date: | 05/16/2018 |
From: | Nuclear Energy Institute |
To: | Office of Nuclear Reactor Regulation |
Benney B | |
References | |
Download: ML18142A249 (35) | |
Text
Public Meeting to Discuss Draft Temporary Instruction 2515/195 NEI Discussion May 16, 2018
© 2018 Nuclear Energy Institute 1
Opening Remarks
- Steve Geier - NEI
- Scot Greenlee - Exelon
© 2018 Nuclear Energy Institute 2
Summary Comments
- The inspection requirements in draft TI 2515/195 are not aligned with the industry methodology and guidance that utilities have committed to implement:
- Flowserve Part 21
- BWROG Guidance
- NEI Anchor Darling Double Disc Gate Valve (ADDDGV) Industry Resolution Plan
- Commitments made by utilities in their December 2017 submittals to the NRC
- The main objective of the TI should be to verify that utilities executed their committed actions
© 2018 Nuclear Energy Institute 3
Summary Comments
- As written, the TI reflects an excessively conservative approach that does not adequately consider:
- The positive results of ADDDGV internal inspections
- The results of existing thread friction testing
- A graded inspection approach using risk
- Existing design criteria for valves
- The Industry has significant concerns with draft TI 2515/195 and asks that the NRC revise it to align with the BWROG guidance (TP16-1-112 rev. 4) and commitments made by utilities in their Dec 2017 submittals to the NRC
© 2018 Nuclear Energy Institute 4
TI Applicability
- The inspection should be limited to active safety-related (SR) MOVs
- The TI should specifically exclude passive safety-related MOVs or SR valves with manual gearboxes from the scope of the inspection
© 2018 Nuclear Energy Institute 5
TI Objectives
- The inspection should focus on verifying execution of what was committed per industry guidance, regarding:
- Identification of affected valves
- Evaluation of valve susceptibility
- Implementation of corrective actions
- The inspection should not be an independent verification that the SR valves are capable of performing their safety function
- Independent verification may implement a level of rigor not appropriate for verifying resolution of this industry issue
- The inspection should focus on implementation of the industry corrective actions rather than just susceptibility
© 2018 Nuclear Energy Institute 6
TI Inspection Requirements
- The evaluation section specifies certain design criteria that is above and beyond industry guidance and current regulation, such as:
- Use of motor actuator stall in evaluating the torque capability of the wedge pin rather than the torque requirements specified in the stations NRC approved GL 96-05 program
- Methodology for evaluating wedge thread shear capacity that may differ from existing approved vendor weak-link analyses
- Review of the press-fit collar design - not required if the wedge pin has adequate torque capacity to handle maximum applied torque
- Use of thread resistance only to determine valve operability for the short term
© 2018 Nuclear Energy Institute 7
Corrective Action
- The industry implemented an effective corrective action plan based on industry guidance
- Diagnostic testing and stem rotation checks as described in BWROG Topical Report TP16-1-112, Rev 4 are effective methods in identifying stem-disc issues
- Torqueing the stem into the wedge to the maximum joint capacity may not be a feasible repair and does not account for other factors (e.g., Inconel pins)
© 2018 Nuclear Energy Institute 8
NRC Inspection Resources
- Planned Inspection Hours in the TI seem inappropriately high
- Estimated time for the inspection is listed as 80 inspection hours
- Additional 24-32 hours for preparation and documentation
- Changing the focus to verification of implementation of industry committed actions would result in more reasonable resource requirements
© 2018 Nuclear Energy Institute 9
Summary
- The industry has aggressively pursued resolution of the ADDDGV issue
- The industry has been very transparent on guidance and criteria being utilized to address the ADDDGV issue
- The guidance and inspection criteria contained in the TI represents a disconnect with the industry on committed actions to resolve the issue
- The Industry has significant concerns with draft TI 2515/195 and asks that the NRC revise it to align with the BWROG guidance and commitments made by utilities in their Dec 2017 submittals to the NRC
© 2018 Nuclear Energy Institute 10
QUESTIONS?
© 2018 Nuclear Energy Institute