Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

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John McFaddenWestinghouseBaffle Bolt Degradation Engineering Issue Manager July 19, 2016Baffle-Former Bolt NSAL-16-1
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

Topics• Westinghouse Tech Bulletin TB-12-5• Nuclear Safety Advisory Letter NSAL-16-1
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

Overview of Internals (Westinghouse NSSS)

Control 

Outlet 

Core Bar

Thermal S

Former 

Hold Dow

Lower Co

Vessel He

Pressure 

Inlet Nozzle

Upper Support Plate

Lower Core Plate

Bottom-Mounted Instrumentation 

Column Body

Lower Support Column Body

Upper Core Plate

Baffle Plate

Upper Support Column
Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

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Westinghouse Technical Bulletin TB-12-5
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

Westinghouse Technical Bulletin TB-12-5• Tech Bulletin TB-12-5 was issued in March 2012 

Fall 2010 Cook Unit 2 visual findings of damaged former bolts

• Identified 7 susceptible 4-loop downflow plants be

affected (Cook 1,2; Salem 1,2; Indian Point 2,3; aCanyon 1)

• Also identified twelve 2- and 3-loop plants with su

designs similar to Cook Unit 2 (i.e., downflow desdesign, bolt loading)

Conclusions of TB stil
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Nuclear Safety Advisory Letter NSAL-16-1
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

Nuclear Safety Advisory Letter (NSAL)• NSAL-16-1 released on July 5

– Westinghouse 4-loop downflow plants are most sus– Impact on other CE and Westinghouse plants has b

evaluated

• Information in TB-12-5, “Baffle Bolt Degradation in 

Westinghouse NSSS Plant with Downflow ReactoDesign” remains applicable 
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

Extent of Condition Evaluation• Affected plants:

– All Westinghouse designed NSSS plants with baffle

bolts and CE designed plants with bolted core shropotentially affected by this issue

– The Westinghouse AP1000® plant design does not 

baffle-former bolts and is not affected by this issue

• Factors contributing to degradation:

– reactor coolant design configuration (upflow vs. dow– plant internals design and flowrates– bolt design

• Affected plants broken down into 4 Tiers

AP1000 is a trademark or registered tradeElectric Company LLC, its affiliates and/or 

States of America and may be registered in the world. All rights reserved. UnauthorizeOther names may be trademarks of their re
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

NSAL Recommendations• General Recommendations for all Tiers:

– If visually damaged baffle-former bolts or lock bars 

detected, it is recommended that the fuel assembliewere adjacent to the baffle in the previous cycle, anscheduled for use in the next cycle, be inspected fowear on the face that was adjacent to the baffle

– It is recommended that the plant continues to follow 

current MRP-227 guidelines and implement any revthe MRP-227 recommendations
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

NSAL Recommendations (cont’d.)• Tier 1a (4-loop downflow plants with Type 347 bolt desig

Complete a UT volumetric inspection of the baffle-former bolts at scheduled refueling outage– In preparation for this inspection, the plant should consider dev

ABPA and be prepared to replace any baffle-former bolts with damage or UT indications

– Long-term mitigation strategies to consider include upflow con

preemptive bolt replacements 

• Tier 1b (4-loop downflow plants with Type 316 bolt des

Complete a VT3 (visual) inspection of the baffle-former bolts at thscheduled refueling outage– If any visual indications are found, it is recommended that the 

completes a UT volumetric inspection of the baffle-former bolts

– If no visual indications are found, it is recommended that the p

completes a UT volumetric inspection of the baffle-former bolts completion of the second refueling outage after the issuance o
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Westinghouse Non-Proprietary Class 3 © 2016 Westinghouse Electric Company 

NSAL Recommendations (cont’d.)• Tier 2a, 2b, and 2c (2- and 3-loop downflow plants): 

– Plants that have previously completed UT inspections should r

inspection records to identify any indication of the onset of clusthe next scheduled refueling outage

– Clustering is defined as 3 or more adjacent bolts or a total num

failures in a single baffle plate > 40% of the total number of bo

baffle plate 

– Any indication of clustering should result in the consideration o

accelerated re-inspection schedule

• Tier 3 (Converted upflow plants): 

– 4-loop plants that have operated in a downflow configuration fo

20 years should evaluate the need to perform a UT volumetric baffle-former bolts on an accelerated schedule

– All other plants should follow the General Recommendations f

provided on Slide 9

• Tier 4 (Designed upflow plants): 

– Follow the General Recommendations for all Tiers provided on