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| issue date = 06/14/2017
| issue date = 06/14/2017
| title = NRC Staff Presentation - Baffle-Former Bolt Inspections at Indian Point
| title = NRC Staff Presentation - Baffle-Former Bolt Inspections at Indian Point
| author name = Rudland D L
| author name = Rudland D
| author affiliation = NRC/NRR
| author affiliation = NRC/NRR
| addressee name =  
| addressee name =  
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| docket = 05000003, 05000247, 05000286
| docket = 05000003, 05000247, 05000286
| license number =  
| license number =  
| contact person = Setzer T C
| contact person = Setzer T
| document type = Meeting Briefing Package/Handouts, Slides and Viewgraphs
| document type = Meeting Briefing Package/Handouts, Slides and Viewgraphs
| page count = 5
| page count = 5
| revision = 0
}}
}}
=Text=
{{#Wiki_filter:BaffleFormer Bolt Inspections at Indian Point Remarks by David L. Rudland Chief, Vessel and Internals Integrity Branch Office of Nuclear Reactor Regulations U.S. Nuclear Regulatory Commission June 14, 2017 ML17171A187
Baffleformer Assembly Direct coolant flow through the core and provides lateral support to the core during a seismic event or loss-of-coolant accident (LOCA).
Stainless steel bolts are 5/8 dia. x ~2 long 2
Baffle Bolt Inspection
* MRP227A covers inspection of reactor internals
  - MRP Letter 2017011 dictated interim guidance
* Ultrasonic inspection technique
  - One probe per bolt, several sensors and channels of data
  - Qualified for detection only - go/no go
* Technique appears conservative
  - >50% of bolts removed retained some load carrying capacity 3
Indian Point, Unit 2 Indian                    Plant Point, Unit 3 EFPY@ Date of UT Exam Total number of baffle-former 28.6    31.1 Mar    Mar 2017    2016    Date of UT Exam 0              No. of visually failed 31 bolts at IP2/3 is 832/unit                      bolts No. of bolts with UT 256    182 4                              indications 3              No. of bolts that could 14 not be UT examined Total No. of Potentially 259    227 Degraded Bolts Recent Inspections at Indian Point 270    278    No. of Bolts Replaced No. Bolts with UT 35      103    indications that failed upon removal
Conclusion
* Structural integrity of baffleformer assembly is maintained at Indian Point due to
  - Replacement of all bolts with UT indications
  - Replacement of additional nondegraded bolts for margin and
  - Subsequent bolt inspections at every refueling outage
* NRC will continue to inspect bolt examination results through the baseline inspection program at Indian Point
* More broadly, the NRC staff will continue to closely monitor the baffleformer bolt operating experience and updated inspection guidance to ensure structural integrity 5}}

Latest revision as of 02:57, 30 October 2019

NRC Staff Presentation - Baffle-Former Bolt Inspections at Indian Point
ML17171A187
Person / Time
Site: Indian Point  Entergy icon.png
Issue date: 06/14/2017
From: David Rudland
Office of Nuclear Reactor Regulation
To:
Setzer T
References
Download: ML17171A187 (5)
v • d • e


Text

BaffleFormer Bolt Inspections at Indian Point Remarks by David L. Rudland Chief, Vessel and Internals Integrity Branch Office of Nuclear Reactor Regulations U.S. Nuclear Regulatory Commission June 14, 2017 ML17171A187

Baffleformer Assembly Direct coolant flow through the core and provides lateral support to the core during a seismic event or loss-of-coolant accident (LOCA).

Stainless steel bolts are 5/8 dia. x ~2 long 2

Baffle Bolt Inspection

  • MRP227A covers inspection of reactor internals

- MRP Letter 2017011 dictated interim guidance

  • Ultrasonic inspection technique

- One probe per bolt, several sensors and channels of data

- Qualified for detection only - go/no go

  • Technique appears conservative

- >50% of bolts removed retained some load carrying capacity 3

Indian Point, Unit 2 Indian Plant Point, Unit 3 EFPY@ Date of UT Exam Total number of baffle-former 28.6 31.1 Mar Mar 2017 2016 Date of UT Exam 0 No. of visually failed 31 bolts at IP2/3 is 832/unit bolts No. of bolts with UT 256 182 4 indications 3 No. of bolts that could 14 not be UT examined Total No. of Potentially 259 227 Degraded Bolts Recent Inspections at Indian Point 270 278 No. of Bolts Replaced No. Bolts with UT 35 103 indications that failed upon removal

Conclusion

  • Structural integrity of baffleformer assembly is maintained at Indian Point due to

- Replacement of all bolts with UT indications

- Replacement of additional nondegraded bolts for margin and

- Subsequent bolt inspections at every refueling outage

  • NRC will continue to inspect bolt examination results through the baseline inspection program at Indian Point
  • More broadly, the NRC staff will continue to closely monitor the baffleformer bolt operating experience and updated inspection guidance to ensure structural integrity 5
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