ML16288A694

Summary of 821216 Meeting W/B&W Owners Group Safe-End Task Force in Bethesda,Md Re Progress on long-term Program for Evaluating Cracking Problem in Plant Makeup Nozzles

ML16288A694
Person / Time
Site:	Davis Besse, Oconee, Arkansas Nuclear, Crystal River, Rancho Seco, 05000000, Crane
Issue date:	01/14/1983
From:	Miner S Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8301240245
Download: ML16288A694 (24)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 JAN 1 4 1983 Dockets Nos. 50-313, 302, 346, 269/270/287, 312 & 289 LICENSEE:

B&W OWNERS SAFE-END TASK FORCE

SUMMARY

OF MEETING HELD ON DECEMBER 16, 1982 WITH THE B&W OWNERS GROUP SAFE-END TASK FORCE TO DISCUSS THE PROGRESS ON ITS LONG TERM PROGRAM FOR EVALUATING THE CRACKING PROBLEM IN B&W PLANT MAKEUP NOZZLES A meeting was held on December 16, 1982 in Bethesda, MD with the B&W Owners Group Safe-End Task Force. The Task Force had completed their evaluation program on the safe-end cracking problem in the makeup/HPI nozzles. The purpose of the meeting was to provide the Task Force the opportunity of discussing with the NRC staff the results of their program and their recommendations for implementing a solution to the cracking problem prior to preparing their final report.

The attendance list (Enclosure 1), the meeting agenda (Enclosure 2) and copies of the viewgraphs used at the meeting (Enclosures 3 thru 21) are enclosed.

Discussion The Task Force initially discussed the background information on their program to evaluate the cause of cracking in the HPI/makeup nozzles (Enclosure 3) including: (1) the location and the design of the nozzles (Enclosures 4 thru 7), (2) the results of inspections of the nozzles at B&W plants (Enclosure 8), (3) their task action plan for the project (Enclosure 9).and (4) the general industrial experience related to thermal sleeve cracking reviewed (Enclosure 10).

In compiling their facts (Enclosure 12) the Task Force looked at a number of variables such as nozzle installation, location, system differences (Enclosure 11).

The Task Force primarily found that there was marginal control of installation of the thermal sleeves in the safe-end nozzles and therefore varying degrees of contact rolls were performed. In addition, all cracked safe-ends were associated with loose thermal sleeves and makeup nozzles. The cracks were ID initiated. They also found that where post instAllation inspections verified that the thermal sleeves were in place and tight no failures had occurred.

The Task Force then discussed the various factors that they considered could have caused the cracking (Enclosure 13).

From their evaluation of the causes they concluded that the probable cause of the cracking was due to loose thermal sleeves allowing hot primary coolant to flow between the thermal sleeve and safe-end. This along with the cold water makeup caused the thermal cycling which caused the thermal fatigue cracking (Enclosure 14).

The goals of the testing conducted as part of the program is shown in 5.

From the testing conducted in the test fixture shown 8301240245 830114 PDR ADOCK 05000269 P

PDR

-2 6 the Task Force determined that thermal sleeves hard rolled to 5% wall thinning would take the forces that are expected to occur during operation (Enclosure 17).

The Task Force also concluded that the thermal sleeves that loosened.and caused the cracking in makeup/HPI nozzles were probably only rolled to less than 1% wall thinning. The thermal sleeves used in the repairs of the cracked makeup/HPI safe-ends at Crystal River-3, Oconee 2 & 3 and Rancho Seco have an expanded roll area (Enclosure 16) and were hard rolled to the 5% wall thinning.

In conclusion, the Task Force recommended (Enclosure 19) that ab a result of inspection the installed thermal sleeve is replaced and the modified thermal sleeve shown in Enclosure 18 should be used as the replacement and that the thermal sleeve be hard rolled into the safe-end to a 5%

wall thinning. In addition, the Task Force recommended an augmented Inservice Inspection (ISI) for the HPI nozzles and the MU/HPI nozzle.

The specific ISI recommendation for these nozzles are shown on Enclosures 20 and 21.

The Task Force pointed out that these wi11' be their recommendations to the individual utilities involved. The final report is scheduled to be completed in December 1983. Each licensee will provide a copy of the report on its docket and it is expected each licensee will delineate those portions of the recormendations< that will be: implemitd at thir plants.

The final reports are expected to be sent to the NRC by the licensees the end of January 1983.

Subsequent to the meeting we were informed that the completion schedule has slipped about one month.

"ORIGINAL SGNED BY:"

Sydney Miner, Sr. Project Manager Operating Reactors Branch #4 Division of Licensing

Enclosures:

1. Attendance List

2.

Mtg. Agenda 3.- 21.

View Graphs cc w/enclosures:

See next page OFFICE OFIEA....

SURNAME 3

)

A......................

RE O R.OP.

1 DATE m

NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RE CORD COPY USGPO: 1981-335-960

ORB#4: DL MEETING

SUMMARY

DISTRIBUTION Licensee:

ANO-1, CR-3, DB-1, Oconee 1/2/3, Rancho Seco, TMII-1

• Copies also sent to those people on service (cc) list for subject plant(s).

C Docket Fil~eD L PDR ORB#4 Rdg GLainas JStolz Project Manager -Siliner Licensing Assistant-RIngram OELD

Heltemes, AEOD IE SShowe (PWR) or CThayer (BWR), IE Meeting Summary File-ORB#4 RFraley, ACRS-10 Program Support Branch.

ORAB, Rm.

542 BGrimes, DEP SSchwartz, DEP SRamos, EPDB FPagano, EPLB Meeting Participants Fm. NRC:

HLBrammer BDLiaw RJacobs ADe Agazio WHazelton MConner SHou EJBrown MEgzeftawy ADromerick

W ATTENDANCE LIST 12/16/82 MTG.

NRC FPC B&W John F. Stolz Gary Westafer Doug Killian H. L. Brammer Larry B. Tittle Glen J. Snyder, P.E.

B. D. Liaw Ray Ganthner Sydney Miner Rick Jacobs Al De Agazio AP&L TECo W. S. Hazelton Monte Conner Margaret C. Snow Thomas E. Hiss Shou-nien Hou Rick Gradomski Earl J. Brown Med EgzeftaWy A. W. Dromerick Consumers Pwr. Co.

SMUD Harry W. Daykin John Sullivan Duke Pwr. Co.

bhn Norris B&W Owners Group Safe End Task Force -

NRC Staff Meeting Agenda December 16, 1982 Meeting Introduction NRC Staff Executive Summary J. Norris

Background

J. Norris History, Inspection Results Task Force Action Plan Phase I R. Ganthner Compilation of Facts, CR-3 Instrumentation Failure Analysis, Industry Experience Phase II R. Ganthner Preliminary Cause, Analysis, Test Plan Phase III J. Norris Cause Determination, Design Change Recommendations, Augmented ISI Summary -

Discussion J. Norris

E osure 3 BACKGROUND

• CRYSTAL RIVER 3 LEAKAGE

• OCONEE INSPECTIONS

• REGULATORY RESPONSE GROUP MEETINGS

• SAFE END TASK FORCE WORK

• "PRELIMINARY FINDINGS" MEETING WITH STAFF TYPICAL PLAN VIEW OF REACTOR COOLANT SYSTEM ARRANGEMENT SHOWING LOCATION OF HPI NOZZLE 21' -61 6"

-0 23'-0" HPI NOZZLE 0

60 30' -4 112" 3' -9 7,8' 5'-8 29" 32 31 -33 121. -5 3"1 32 11 7 31" 32

Iosure 5 TYPICAL ELEVATION VIEW OF REACTOR COOLANT SYSTEM ARRANGEMENT SHOWING LOCATION OF HPI NOZZLE HPI 72

-0" NOZZLE 31 -0 24 -0"

TYPICAL LAYOUT OFJIlPI OR HPI/N1U LINE SUPPORTS/

RESTRAIN4T 11J1 OR ilPI/Mu NOZZLE WARMING VALVE BY-PASS tiLN (MU ONLY)

CJST(V-iER B&W IIARDWARE HARDWARE RC COLD LEG PIPE

TYPICAL HPI AND HPI/MJ NOZZLE

.010" TO.015" DIAMETRICAL CLEARANCE BETNEEN THERMAL SLEEVE AND NOZZLE I.D.

SAFE END THERMAL SLEEVE CONTACT EXPANDED 16 1/8" REF

INSPECION RESULTS WYXY yz zW Oconee I Makeup/HP I l

MakeIil plP I

OK Or OK Oconee 2 HPI HPI Maikeup/IPI Makeup/HP 1/32" Gap Slee've rirrumferential Safe End Cracked OK Sleeve Tight Crack tr.eve light Sleeve Loose Buttons Missing Oconee 3 Hip I lpI Makeup/lipI Makeup/iPI 0.030" Gap OK Safe End Cracked OK Sleeve light Sleeve Loose Buttons Missing Crystal River 3 HPI Makent/IlPI lipI ipI OK Safe Ind (racked OK SIeevv I nose Buttons Missing Davis Besse l liPI Makeup/IIPI lip, IpF OK OK OK OK HllP Makeup/tll HPI HPI OK OK OK OK rr?

AN0-1 HPI Makeup/i'!

lipI HPI OK Sleeve Circumferential Partial Gap Sleeve Loose Crack -

Sleeve Tight Buttons Missing Sleeve Tight Rancho Seco HPI H-p Makeup/lPI lip1 OK OK Safe End Cracked Sleeve Loose Sleeve Missing Buttons Hissing Buttons Worn N-l

SAFE END TASK FORCE ACTION PLAN ONE FOUR PHASE I MONTH PHASE II MONTHS PHASE III I

II COMPILE FACTS II IOPERATIONAL REVIEW INDUSTRY EXPERIENCE EVALUATE IA I

I ADDITIONAL INSTRUMENTATION I I

CR-3 DATA EVALUATION I

PRELIMINARY CAUSE AUGiNENTE CR-3 DETERMINATION UT DRAFT TEST PLANS EVALUATE LI TESTING PLANjS I

IMPLEMENT TEST PLAN ANALYSES I

DESIGN CHANGE I

FAILURE ANALYSIS I

EORT I

II

,II LONG TERM JUSTIFICATION OF OPERATION

Encl re 10 INDUSTRY EXPERIENCE REVIEW MI-PRg, INDIAN POINT-1 1970 GE-BWR, FEEDWATER NOZZLE/SPARGER CRACKING 1974-1980 GE-BWR, CONTROL ROD DRIVE RETURN LINE NOZZLE CRACKING 1975 W-PWR, STEAM GENERATOR FEEDWATER LINE CRACKING 1979 W-PWR, SAFETY INJECTION SYSTEM THERMAL SLEEVES 1982 1

COMPILATION OF FACTS NOZZLE FUNCTION, LOCATION, GEOMETRY DESIGN HISTORY AND MATERIAL INSTALLATION PROCEDURES AS BUILT DIMENSIONS AND CLEARANCES OPERATING DIFFERENCES PRE-1982 INSPECTIONS/RESULTS SYSTEM DIFFERENCES

- MU PUMP DIFFERENCES PIPING

- BYPASS FLOW

- HPI TRANSIENTS

- RCS CONDITIONS

- MU TEMPERATURE CHEMISTRY RCS CONDITIONS

En lsure 12 FACTS

1. THERE WAS MARGINAL PROCEDURAL CONTROL OF THE INITIAL INSTALLATION OF THE CONTACT EXPANSION ROLL,

2. VARYING DEGREES OF CONTACT EXPANSION ROLLS COULD BE PERFORMED EVEN FOR THE SAME NSS.

3. DURING THERMAL TRANSIENTS, FOR SLEEVES NOT HARD ROLLED, AN INSTANTANEOUS GAP CAN OCCUR DUE TO DIFFERENTIAL THERMAL CONTRACTION OF THE THERMAL SLEEVE AND SAFE END.

4.

ALL CRACKED SAFE ENDS WERE ASSOCIATED WITH LOOSE THERMAL SLEEVES. HOWEVER, NOT ALL LOOSE THERMAL SLEEVES HAD SAFE ENDS THAT WERE CRACKED.

5. ALL CRACKED SAFE ENDS WERE ASSOCIATED WITH THE MAKE UP NOZZLE.

6. THE MAKE UP NOZZLE IS SUBJECT TO RANDOM AND CONTINUOUS OSCILLATIONS OF MAKE UP FLOW.

7. THE CRACKS FOUND ARE ID INITIATED,

8. THE CRACKS WERE PROPAGATED BY THERMAL FATIGUE.

9. WHERE POST INSTALLATION INSPECTIONS VERIFIED THE THERMAL SLEEVE IN PLACE AND TIGHT, NO FAILURES HAVE OCCURED.

End re 13 CAUSES CONSIDERED

1. MAKEUP FLOW CONDITIONS MAINTAINED OUTSIDE OF DESIGN LIMITS.

2. EXCESSIVE CYCLING OF THE CHECK VALVE DUE TO IMPROPER VALVE PERFORMANCE.

3. FLOW STRATIFICATION IN THE MU LINE DUE TO MINIMAL MU FLOW.

4.

THERMAL STRATIFICATION AND RECIRCULATION INTHE MU LINE DUE TO MINIMAL FLOW.

5. COLD WORKING OF THE THERMAL SLEEVE DUE TO ROLL EXPANSION.

6. STRESS CORROSION CRACKING OF THE THERMAL SLEEVE DUE TO EXCESSIVE ROLL EXPANSION,

7. CONVECTIVE HEATING OF THE SAFE-END DUE TO AN AIR GAP IN THE INSULATION.

8. EXTERNAL LOADING OF THE ATTACHED PIPING DUE TO THERMAL TRANSIENTS.

9. SYMPATHETIC VIBRATION OF THE THERMAL SLEEVE DUE TO DYNAMIC PRESSURE FIELD GENERATED BY THE RC PUMPS.

10. FLOW INDUCED VIBRATIONS DUE TO CROSS-FLOW IN THE RC COLD LEG PIPE.

11. ANNULAR FLOW BETWEEN THE THERMAL SLEEVE OD AND THE SAFE END ID DUE TO INADEQUATE ROLLING OF THE THERMAL SLEEVES.

Olosure 14 PROBABLE FAILURE CAUSE THE PROBABLE FAILURE CAUSE IS THAT THE THERMAL SLEEVE IS LOOSE AFTER CONSTRUCTION OR A MINIMUM CONTACT EXPANSION ROLL BECOMES LOOSE DURING OPERATION DUE TO MECHANICAL VIBRATION AND/OR THERMAL CYCLING OF THE CONTACT EXPANSION JOINT. THIS LOOSENESS CAUSES WEAR OF THE 0) OF THE THERMAL SLEEVE AND THE ID OF THE SAFE-END. THIS WEAR IN THE ROLLED AREA ALLOWS A LARGER GAP TO FORM BETWEEN THE THERMAL SLEEVE AND SAFE-END. THE HOT COOLANT RANDOMLY IMPACTS THE SAFE-END AND THERMAL SLEEVE AREA BECAUSE OF RANDOM MOTIONS OF THE SLEEVE.

THE COOLER MAKEUP FLOW COOLS THESE HEATED AREAS WHEN RANDOM MOTION SHUTS OFF THE ANNULAR FLOW OR MAKEUP FLOW IS INCREASED. THIS RANDOM ALTERNATING HEATING AND COOLING EVENTUALLY CAUSES THERMAL FATIGUE CRACKING OF THE SAFE-END.

5 TEST PLAN GOALS

1. DEMONSTRATE THAT SLEEVES INSTALLED NOW WILL PERFORM,

2. QUANTIFY NATURAL FREQUENCY OF THE SLEEVE.

3. CONFIRM CALCULATED PARAMETERS,

4.

DEMONSTRATE THE EXPANSION ROLLING PROCEDURE AND TECHNIQUE.

En ure 16 ACCESS HOLE & PLUG TENSILE TEST MACHINE TOP MANIFOLD IINLET PIPE SIMULATED SAFE END HEATER ROLL EXPANDED AREA ('2" WIDE)

BLANKETS 361 AROUND SIMULATED THERMAL SLEEVE MAI FO0LD0 EXIT PIPE TENSILE TEST MACHINE ROLL EXPANSION TEST SCHEMATIC DIAGRAM OF TEST FIXTURE

Lnciosure Y/

HPI/MU STATIC TEST RESULTS 12K CD c

3 6K

-J U

1 2

3 4

5 6

7 8

PERCENT WALL THINNING

REPAIR DESIGN MODIFICATION NEW THERMAL SLEEVE DESIGN 2.000" DIA. REF HARD ROLL EXPAND CONTACT SF N

EXPANDSSAFEZLND

-1.500" OIA RE)F SLEEE BWEN TRERMAL x

SLEE&NOZE ID 9

TASK FORCE RECOMMENDATIONS

• HARD ROLL WHEN REQUIRED BY INSPECTIONS

• MODIFIED THERMAL SLEEVE DESIGN

• AUGMENTED ISI 0

AUGMENTED ISI HPI NOZZLES UNREPAIRED RT DURING NEXT 5 REFUELING OUTAGES RT EVERY 5TH REFUELING OUTAGE THEREAFTER REPAIRED (NEW SLEEVE DESIGN)

RT & UT 1ST, 3RD & 5TH REFUELING OUTAGES RT EVERY 5TH REFUELING OUTAGE THEREAFTER REPAIRED (REROLLED)

RT DURING NEXT 5 REFUELING OUTAGES RT EVERY 5TH REFUELING OUTAGE THEREAFTER 1

AUGMENTED ISI MAKEUP NOZZLES UNREPAIRED RT & UT NEXT 5 REFUELING OUTAGES RT & UT EVERY 5TH REFUELING OUTAGE THEREAFTER REPAIRED (NEW THERMAL SLEEVE & REROLL)

RT & UT IST, 3RD & 5TH REFUELING OUTAGE RT & UT EVERY 5TH REFUELING OUTAGE THEREAFTER