ML20205B392

Forwards Summary of 880908 Enforcement Conference Re Instrument Installation Deficiencies & non-conservatisms in Instrument Settings Associated W/Hpci/Rcic High Steam Line Flow Isolation.Related Info,Including Attendees List Encl

ML20205B392
Person / Time
Site:	Brunswick
Issue date:	10/05/1988
From:	Ernst M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Utley E CAROLINA POWER & LIGHT CO.
References
NUDOCS 8810260235
Download: ML20205B392 (42)

Text

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4 DCT 0 s 199g Docket Nos. 50-325, 50-324 License Nos. OPR-71, DPR-62 Carolita Power and Light Corapany

/ ATTN: Mr. E. E. Utley Senior Executive Vice President Power Supply and Engineering and Construction P. O. Box 1%1 Raleigh, NC 27602 .

Gentlemen:

SUBJECT:

ENFORCEMENT CONFERENCE

SUMMARY

This letter refers to the Enforcement Conference held at our request on September 8, 1988. This conference concerned activities authorized for The issues discussed at the meeting related to:

y(our Brunswick facility.

1) instrument installation deficiencies and non-conservatisms in the 4 instrument settings associated with High Pressure Coolant Injection (HPCI)/ l Reactor Core Isolation Cooling (RCIC) high steam line flow isolation; (2) apparent inadequate corrective action related to operability of safety related DC motor operated valves; and (3) electrical switchboard operability as it relates to the apparent inadequacy of actions taken to identify and correct I

silicon bronze bolt failures.

l A list of attendees, a sumary, and a copy of your handout are enclosed. We I are continuing our review of those issues to determine the appropriate enforce-ment action.

In accordance with Section 2.790 of the NRC's "Rules of Practice," Part 2 Title 10, Code of Federal Regulations, a copy of the letter and its enclosures will be placed in the NRC Public Document Room.

Should you have any questions concerning this letter, please contact us.

Sincerely, h

Malcolm L. Ernst, Acting Regional Administrator

Enclosures:

1. List of Attendees

2. Management Meeting Sumary

3. Licensee Handout ec w/encls: (See page 2) 8810260235 GS1005 i PDR ADOCK 05000324 1 Q PDC {

4 OCT C5 MM Carolina Power and Light Company 2 cc w/encls:

vt. W. Howe, Vice President

• /. JBrunswick Nuclear L. Harness, Project Manager Plant General l State of North Carolins l

l bec w/encls:

vhRC Resident Inspector DRS,, Technical Assistant Document Control Desk vJ. Lieberman, Director Office of Enforcement t

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, OCT0$ 199 ENCLOSURE 1 LIST OF ATTENDEES CAROLINA POWER AND LIGHT M. A. McDuffie, Senior Vice President, Nuclear Generation P. W. Howe, Vice President, Brunswick Nuclear Project M. A. Jones, Director, Onsite Nuclear Safety l J. L. Harness, General Manager, Brunswick R. E. Helme, Manager, Technical Support L.1. Loflin, Section Manager Nuclear Licensing '

J. O'Sullivan. Special Project Manager, Brunswick J. S. Boone, Principal Engineer, Technical Support G. A. Thompson, Project Engineer, Electrical Systems l W. J. Schade, Senior Electrical Engineer NUCLEAR REGULATORY COMN!SSION. Ril l M. L. Ernst Deputy Regional Administrator  !

C. W. Hehl, Deputy Director. Division of Reactor Projects (DRP)  !

A. F. Gibson, Director, Di.*ision of Reactor Safety (DRS) '

G. R. Jenkins, Director, Enforcement and Investigation Coordination Staff (EICS)

A. R. Herdt, Chief Engineering Branch, DRS P. E. Fredrickson, Chief, Projects Section 1A(PS-1A),DRP T. E. Conlon, Chief Plant Systems Section (PSS) DRS '

F, Jape, Chief. Test Programs Section (TPS) DRS .

W. H. Ruland, Senior Resident Inspector, PS-1A, DRP  !

R. E. Carroll, Project Engineer, PS-1A, DRP [

B. Uryc, Enforcement Coordinator, EICS >

P. J. Fillion. Reactor Inspector, PSS, DRS R. H. Bernhard, Reactor Inspector, TPS, DRS

, J. L. Coley, Reactor Inspector, Materials and Processes Section. DRS e S. G. Tingen, Reactor Inspector, TPS DRS .

i NUCLEAR REGULATORY COPNISSION. HEADQUARTERS G. C. Iainas, Assistant Director for Region !! Reactors. Division of Reactor !

Projects NRR l

J. Lieberman, Director, Office of Enforcement  !

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. OCT i s 199 p.

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ENCLOStJRE 2 l l

EN/N CEMEN1 CONFERENCE

SUMMARY

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ihe Deputy Regional Administrator opened the meeting by indicating that the tbee issues to be discussed (i.e. , OC motor valve failures / design inade- t qucio. non-conservative HPC1/RCIO high steam flow setpoints, and silicon  ;

tronze bolt failures) appeared to exhibit a cocrnon weakness in management L w reness ud followup. AdditionaHy, he expressed a concern over the amount (

9f MC iMervention/proding that was rreired in two uf the issues before they i rfat resolved, Acknowledging their understanding of NRC's concerns, CP&L began L t%ir presecution by discusstag the probh.m of inadequate DC motor torque as l' tt relates to origim! design features, included in this design features discusion were the generic aspects of the DC motors' starting resistors,  !

absence of thermal overload protection, '.coperature effect on motor-winding  :

resistance, and inadequate cab?e siting. Tha licensee also addressed earlier [

CP&L studies / activities that, on first glunce, apaeared as though they should have alerted CPtL of the CC motor design inc.equscia. Th*se studies /activi-ties included the licentee's 1984 voltage stvy, M8T HPCI SSFI, IEB 85-03 ,

activitlisi and the DC motor fsilure history. 10 all these reviews, CP&L '

indicated : hat their efforts were flawed, in th4t tney accepted the design >

. basis as t'e$ng fondsmentally correct and, thus, dhi not sufficiently challenge  ;

its accuracy. Lihen asked by NRC, the licensee s'at)d that it wasn't until the l third known (41We of HPCI stern admission valve 441-F001 in May 1988, that the existence of starting resistors wu recognized c possibly presenting an ,

operability problen. However, a fourth failure in i <te June 1988 Occurred '

before startig resistors were confirmed as an operaMity problem and the i HPCI injectiew valve E41-F006 on both Units were determined to be undersized. ,

The licensee shut both Units down to replace the undersized F006 motors and i increase cable size; jumpered around starting resistors on motors with an L opening safety functioni and initiated a study to ensure that an adequate >

operating margin exists for all safety-related motor operated valves. ,

< Additionally, CP&L indicated that other modifications were under development  !

(i.e., removal of energized shunt field, itestallation of induced voltage  !

protection, etc.) and that activities to procure new DC motors has been  ;

initiated. l With respect to the HRl/RCIC high steam flow instrumentation problems CP&L j pointed out that these instrvnents were backed up by area high temperature ,

switches which would also &<ect and provide adequate isolatins./protecthn from i a HPCI/RCIC Steam line breat. The licensee then presented a chronology of the i HPCI/RCIC instrument problems, including the observed setpoint driftt cod l J potential pipe sloping problem identified in tdovember 1987; the initial pipe i sloping analysis and subsequent tower Mg of setpoints which toak pW:e in the .

February thru March, 1988 time frame; a second analysis (change from GE to ASME l 1 r'ethodologies) and subsequent lowering of setpoints which tock place in etriy r June 1988; and the special tetting conducted at tne end of June 1988 which  !

id?ntified reversed high and law sensing lines on the Unit 2 HPCI N005 Instrt.-  ;

ment and non-conservative setpoir.ts (i.e. , greater then Technical Srecifica-  ;

) tions) for both Units' HPCI N004 instruments, in dhcussing the luter set of l i

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Enclosure 2 2 00T 4 5 1988 problems, the licensee indicated that the N005 instrument, like all the others, has trips present in both the positive and negative direction; therefore, it ,

would have functioned in spite of the swapped sensing lines. However, its  !

setpoint was found to be above the Technical Specification (TS) limit of 3001  :

flov. The non-conservatism in the setpoints of the N004 instruments was i deuribed by CP&L as being due to the negative standby readings not being i considered during start up testing. The NRC pointed out that the Senior t Resident Inspector had discussed with CP&L and identified as an unresolved item in his November 1987 inspection report, this very same problem. CP&L had no ,

response as to why it took from November 1987 until June 1988 to resolve this problem; but said they would pursue the matter. The licensee then indicated  ;

that as a result of a very recent analysis, the only instruments that were at i any time outside the TS 300% flow setpoint limit were the three addressed ,

above; thus, all other instrument setpoint reductions whien took place were  ;

characterized by the licensee as unnecessary. Additionally, when questioned, l the licensee confirmed that even with the non-conservative setpoints, there l' would be no impact on EQ profiles.

Regarding the failure of silicon bronze bolts in safety-related motor control centers (MCCs) CP&L presented a chronology of events (from January 1986 to the present) in an attempt to demonstrate that appropriate corrective action was r taken based on the facts known at the time. By November of 1986, 16 silicon l brone carriage head (SBCH) bolts had been found failed (three 1/2-inch in '

shippina splits and thirteen 5/16-inch in vertical-to-horizontal bus bar connections). CP&L 'ndicated that a study perfomed at that time showed the  !

1/2-inch SBCH bolt failures were due to overtorquing. Although no such i correlation could be drawn on the 5/16-inch SBCH bolts in the vertical-to- ,

l horizontal bus bar connections, they too were recomended to be replaced with j like SBCH bolts during routine MCC preventive maintenance, in retrospect, the ,

licensee indicated that they saw the lack of any further analysis in November  !

1986 on the 5/16-inch SBCH bolts as an "inefficiency"; but, at that time, the i i failures were considered random. CP&L emphasized that it wasn't until a l special inspection during the dual Unit outage (January - February 1988 time ,

frame) that a significant number of 5/16-inch SBCH bolts had been found with  !

cracked / broken heads. According to CP&L, this was the only time where, in conjunction with a seismic event, bolt failures could hAve rendered saftty (

equipment inoperable.  ;

The discussion then proceeded on to the April - May time frame when inter-granular stress :orrosion cracking (IGSCC) was identified as the failure  ;

mechanism and it's accelerated attack on previously replaced SBCH bolts was  ;

identified. The NRC pointed out that during this period there appeared to be some comunications problem between the Maintenance people working in the MCCs i and the Technical Support Group as to the existence of additional sizes, types, i and locations cf silicon bronze bolts. The licensee agreed and said the system l engineering concept was being enhanced to assume the lead role in problem i investigation. They also indicated that although considered appropriate, i plant-to-NRC comunications could also be improved. Returning to NRC's opening  ;

remarks concerning NRC intervention and a need for more CP&L management  :

' awareness / follow-up, the licensee stated that the reason other size SBCH bolts j r

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• t OCT 0 51313 Enclosure 2 3 and silicon bronze hex head bolts were not initially considereo to be ir.cluded in the IGSCC Sampling program was that there had been no known failures. They agreed tha+, their root cause analysi1 should have been pursued more aggressively, i

and that a strengthened corrective action program should result in improvement",.

As the root cause for the !GSCC is not yet kr.own, CP&L indicated that they will -

i continue replacing the bolts with stcel ones 3rd sample remaining acces;ible silicon bronze bolts in the MCC, at well as develop air sampling inside the  !

! MCCs.

CP&L concluded their presentation by assuring the NPC that Brunswick manageeent I is tctally committed to safe, correct, and reliable operation of the power i'

plant. The Deputy Regional Administrator subsequently closed the meeting by ,

agreeing with CP&L's commitment to the safe operation of th11r plant and L thanked them for their time, I

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ENCLOSURE 3

. i CAROLINA POWER t l!GHT COMPANY l BRUNSWICK STEAM ELECTRIC PLANT  !

ENFORCEMENT CONFERENCE  !

SEPTEMBER S, 1988 j AGENDA OPENING COMMENTS P. W. HOWE DC MOTOR DESICN J. O'SULLIVAN HPCl/RCIC STEAM LEAK J. S. BOONE DETECTION INSTRUMENTATION SILICON BRONZE BOLTS R. E. HELME CLOSING REhARKS J. L. HARNESS 2

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CAROLINA POWER & LIGl!T COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 DC MOTOR ISSUES l o AGENDA INTRODUCTORY STATENENT i

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t ORIGINAL DESIGN FEATURES 1984 VOLTAGE STUDY 1987 SSFI MOTOR FAILURE HISTORY IEB 85-03 ACTIVITIES' OPERABILITY ISSUES I CORRECTIVE ACTIONS ,

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CAROLINA POWER & LIGHT COMPANY l BRUNSWICK STEAM ELECTRIC PLANT !

. ENFORCEMENT CONFERENCE

- SEPTEMBER 8, 1988 ORIGINAL DESIGN FEATURES STARTING RESISTORS

• MOTOR CASING HEATING ELEMENTS SHUNT FIELD CONTINU0USLY ENERGIZED ABSENCE OF INDUCED VOLTAGE PROTECTION ABSENCE OF THERMAL-0VERLOAD PROTECTION

• TEMPERATURE EFFECT ON MOTOR-WINDING RESISTANCE

• CABLE SIZING *

' GENERIC ISSUES

c: '

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 BATTERY V0LTAGE STUDY SPECIAL STUDY TO ASSESS THE EFFECT OF STARTING RESISTORS AND CABLE IMPEDANCE DID NOT CONSIDER DEGRADED VOLTAGE AND ACCIDENT TEMPERATURES INCORRECT AMBIENT TEMPERATURE ASSUMED REPORT CONCLUSION MISLEADING

- CONFLICTS BETWEEN ACCEPTABILITY CRITERION, PROBLEM STATEMENT, AND ACTUAL FINDINGS 1

CAROLINA POWER & LIGHT COMPANY BRUNSWICY, STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 SELF-INITIATED SSFI HPCI SYSTEM 200+ ITEMS / QUESTIONS REDUCED VOLTAGE STARTING MOTOR SIZING RESPONSES DEVELOPED USING EXISTING CONCEPTS AND REFERENCES

. DID NOT DETECT SUBTLETIES J r I

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 DC MOTOR FAILURES DESIGN INADEQUACIES DISCOVERED IN JULY 1988 WERE IN THE HPCI WATER' INJECTION VALVE (E41-F006) AND THE HPCI TURBINE STEAM ADMISSION VALVE (E41-F001).

PREVIOUS MOTOR FAILURES OF F006 AND F001:

1-E41-F001 OCTOBER 1986 DECEMBER 1987 MAY 1988 JUNE 1988 1-E41-F0i)6 JANUARY 1987 2-E41-F001 NONE 2-E41-F006 NONE l

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTP.IC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 IEB 85-03 o BULLETIN TASKING REVIEW AND DOCUMENT THE DESIGN AND BASIS FOR EACH VALVE DOCUMENTATION SHOULD INCLUDE MAXIMUM DIFFERENTIAL PRESSURE OPENING AND CLOSING ESTABLISH TORQUE SWITCH SETTINGS TO MEET THOSE REQUIREMENTS CHANGE INDIVIDUAL VALVE SETTINGS ESTABLISH CONTROLS TO MAINTAIN SWITCH SETTINGS TESTING ACTIVITIES REVIEWED BY LIMITORQUE ENGINEERS r

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 OPERABILITY ISSUES o F001/F006 VALVES OUTSIDE CALCULATED DESIGN MARGIN BY DEFINITION - INOPERABLE LC0 ENTERED UPON DETERMINING IN0PERABILITY BOTH UNITS SHUT DOWN FOR MODIFICATION WORST CASE TEMPERATURE AND VOLTAGE ASSUMPTIONS USED IN CALCULATIONS CONSERVATISM IN VENDOR CALCULATIONS ACTUAL CONDITIONS MORE FAVORABLE THAN CALCULATED -

CONDITIONS y

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CORRECTIVE ACTIONS o COMPLETED BOTH UNITS SHUT DOWN TO REPLACE MOTORS AND INCREASE CABLE SIZE INITIATED A STUDY TO ENSURE THAT ADEQUATE OPERATING MARGIN EXISTS FOR ALL SAFETY-RELATED MOVs JUMPERED STARTING RESISTORS ON MOTORS WITH AN OPENING SAFETY FUNCTION STUDY CONDUCTED BY VENDOR REPRESENTATIVE TO ASSESS VALVE APPLICATION o IN PROGRESS / PLANNED MODIFICATIONS UNDER DEVELOPMENT REMOVE ENERGIZED SHUNT FIELD REMOVE MOTOR CASING HEATERS INSTALL INDUCED VOLTAGE PROTECTION INSTALL THERMAL TRIP DEVICES i INITIATE PURCHASE ACTIVITIES TO PROCURE NEW DC MOTORS IN!TIATE OTHER MODIFICATIONS AS REQUIRED 1

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 HPCI/RCIC LEAK DETECTION INSTRUMENTATION o LEAK DETECTION INSTRUMENTATION o EVENTS o ISSUES o SAFETY SIGNIFICANCE -

o ADEQUACY OF BSEP's INVESTIGATION o CONCLUSIONS f

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 LEAK DETECTION INSTRUMENTATION o PURPOSE DETECT HPC1/RCIC STEAM LINE BREAK LIMIT LOSS OF INVENTORY FROM REACTOR LIMIT BREAK IMPACT ON REACTOR BUILDING ENVIRONMENT o DESIGN HIGH TEMPERATURE SWITCHES DETECT FULL RANGE OF BREAKS TWO REDUNDANT DIVISIONS 30-MINUTE TIME DELAY FOR SOME RCIC SWITCHES HIGH STEAM FLOW DETECTS BREAKS > 300% OF RATED STEAM FLOW

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 LEAK DETECTION INSTRUMENTATION (CONTINUED)

TWO REDUNDANT DIVISIONS SEPARATE ELB0W TAP PER DIVISION ORIGINALLY HAD MECHANICAL DIFFERENTIAL PRESSURE SWITCHES REPLACED WITH ANALOG INSTRUMENTATION SETPOINTS +300% RATED FLOW, STEAM LINE BREAK

-300% RATED FLOW, INSTRUMENT LINE BREAK

. .c CAROLINA POWER & LIGHT COMPANY  :

BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 EVENTS o INSTRUMENT DRIFT SLIGHT INCREASE IN STANDBY READING OF 2-E41-N004 .

INVESTIGATION IDENTIFIED POSSIBLE PIPE SLOPING PROBLEMS WHICH COULD CREATE VAPOR P0CKETS o SETPOINT REVIEW INITIALLY CONCERNED WITH IMPACT OF POSSIBLE SLOPING PROBLEMS UNCERTAINTY IN ADEQUACY OF ORIGINAL CALCULATIONS o SWITCHED INSTRUMENT PIPING ,

i FOUND 2-E41-N005 WITH SWITCHED PIPING i i

ISSUES o WHAT WAS SAFETY SIGNIFICANCE?

o WAS BSEP's INVESTIGATION ADEQUATE AND TIMELY?

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 SAFETY SIGNIFICANCE o CONCLUSIONS  ;

NO SAFETY SIGNIFICANCE OF EVENTS SOME TECHNICAL SPECIFICATION REQUIREMENTS NOT FULLY SATISFIED REQUIRED PERFORMANCE CAPABILITY NOT AFFECTED HOWEVER o BASIS FOR , , .

INSTRUMENT DRIFT INCREASE TOWARDS SETPOINT SO OPERABILITY NOT AFFECTED EFFECTIVELY LOWERED SETPOINT ADEQUATE MARGIN REMAINED FOR STARTUP FLOW SPIKE POTENTIAL VAPOR P0CKETS WOULD HAVE INSIGNIFICANT EFFECT ON CHANGE IN DIFFERENTIAL PRESSURE FOR BREAK FLOW SETPOINT REDUCTIONS FOR P0TENTIAL SLOPING -

PROBLENS NOT ACTUALLY NEEDED

i CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 l

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( SAFETY SIGNIFICANCE (CONTINUED)

SETPOINT REVIEW l

SETPOINT BASED UPON TEST DATA IS THE MOST APPROPRIATE METHOD l 1

RECENT TEST RESULTS COMPARABLE WITH STARTUP RESULTS EITHER SET OF DATA ACCEPTABLE SOME DIFFERENCES EXPECTED DUE TO DIFFERENCES IN CONDITIONS AND EXTRAPOLATION TO DESIGN CONDITIONS i

SETPOINTS FOR 1 AND 2-E41-N004 FOUND TO EXCEED TECHNICAL i

SPECIFICATION LIMIT NEGATIVE STANDBY READINGS NOT CONSIDERED DURING STARTUP TRIP AT SLIGHTLY HIGHER FLOWS PREVIOUS SETPOINT REDUCTIONS FOR OTHER REASONS NOW CONSIDERED TO HAVE BEEN UNNECESSARY

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 SAFETY SIGNIFICANCE (CONTINUED)

SWITCHED INSTRUMENT PIPING TRIP FUNCTION OF 2-E41-N005 NOT LOST TRIPS PRESENT FOR BOTH (+) 300% AND (-) 300% FLOW SETPOINT EXCEEDED TECHNICAL SPECIFICATION LIMIT HOWEVER TRIP AT SLIGHTLY HIGHER FLOW

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 SAFETY SIGNIFICANCE (CONTINUED) o

SUMMARY

RCIC CAPABILITY NOT REDUCED OR AFFECTED HPCI 1-E41-N004, 2-E41-N004, AND 2-E41-N005 HIGH FLOW SETPOINTS EXCEEDED TECHNICAL SPECIFICATION LIMIT NO IMPACT ON EQ PROFILES LIMITING PROFILES BASED UPON 1000 LB/SEC DEG BREAK EQ 300% BREAK CASE ASSUMED 160 LB/SEC EVEN WITH HIGHER 300% BREAK FLOW, DEG CASE REMAINS BOUNDING BY SEVERAL FACTORS FULLY REDUNDANT LEAK DETECTION CAPABILITY PROVIDED BY HPCI AND RCIC AREA HIGH TEMPERATURE SWITCHES

- NECESSARY DIVERSE, REDUNDANT ISOLATION CAPABILITY RETAINED NO SAFETY SIGNIFICANCE BASED UPON DESIGN BASIS

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 ADEQUACY OF BhEP'S INVESTIGATION o INITIATING EVENT WAS CHANGED IN STANDBY READING OF 2-E41-N004 ONE-HALF DIVISION CHANGE ON 11/3/87 CHANGE WAS NOT SIGNIFICANT RESPONSE WAS PROMPT SUBSEQUENT CHANGES (11/7 AND 11/24) BROUGHT INCREASED ATTENTION INVESTIGATION INCLUDED FIELD TESTING, ANALYSIS, AND DOCUMENT REVIEWS -

POTENTIAL PIPE SLOPING PROBLEM IDENTIFIED CONDITIONS CONFIRMED AT FIRST OPPORTUNITY EVALUATION PREPARED BEFORE STARTUP TO LOWER SETPOINTS ACTION WAS BASED UPON "WORST CASE" ASSUMPTIONS AND AN EXPEDITED ASSESSMENT ACTUAL EFFECT THOUGHT TO BE INSIGNIFICANT S0 NO REASON IDENTIFIED FOR TECHNICAL SPECIFICATION OPERABILITY CONCERNS

.- _l

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 ADEQUACY OF BSEP'S INVESTIGATION (CONTINUED)

FINAL EVALUATION CONCLUDES SLOPING PROBLEM HAS AN INSIGNIFICANT EFFECT ON SETPOINTS SETPOINT CHANGES WERE NOT NEEDED FOR THIS REASON ORIGINAL JUDGMENT CONFIRMED o SETPOINT REVIEW PIPE SLOPING PROBLEM CREATED POSSIBLE NEED FOR ADDED MARGIN IN SETPOINT SLOPING WAS POSSIBLE CONSTRUCTION DEFICIENCY CONCERN DID NOT INDICATE PROBLEMS WITH ORIGINAL SETPOINT DETERMINATION ORIGINAL SETPOINTS DETERM!NED BY GE WITH NO REASON TO QUESTION THEIR CORRECTNESS SEVERAL METHODS AVAILABLE TO DETERMINE SETPOINT EACH ATTEMPT PRODUCED MORE CONSERVATIVE RESULTS FOR AT LEAST ONE INSTRUMENT

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 ADEQUACY OF BSEP'S INVESTIGATION EXPEDITED CONSERVATIVE ACTION LED TO DECREASING SETPOINTS FINAL EVALUATION DETERMINED USE OF TEST DATA MOST APPROPRIATE MOST SETPOINT REDUCTIONS WERE UNNECESSARY REVIEW DID FIND TWO SETPOINTS WERE NOT PROPERLY ADJUSTED DURING STARTUP FOR NEGATIVE STANDBY READING 1-E41-N004 2-E41-N004 TECHNICAL SPECIFICATION LC0 REQUIREMENTS MET ONCE DEFICIENCIES WERE DETERMINED o SWITCHED INSTRUMENT PIPING PREVIOUS PROBLEMS DID NOT INDICATE POTENTIAL PROBLEM WITH CROSSED-INSTRUMENT PIPING PROBLEM NOT OBSERVABLE EXPECT WHILE OPERATING HPCI INDICATOR NOT OBSERVABLE FROM CONTROL ROOM

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 ADEQUACY OF BSEP'S INVESTIGATION (CONTINUED)

ORIGINAL CONSTRUCTION CROSSED PIPING IDENTIFIED IN DRYWELL DURING CONSTRUCTION DRAWING ISSUED TO CORRECT AT INSTRUMENT RACK PLANT MODIFICATIONS NO MODIFICATIONS TO DRYWELL PIPING MODIFICATIONS TO OUTSIDE PIPING ONLY REPLACED INSTRUMENTS OR VALVES NO PIPING CHANGES PLANNED QC "AS BUILTS" PER DRAWINGS PERFORMED

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CONCLUSIONS o NO SAFETY SIGNIFICANCE HIGH FLOW LOGIC WOULD HAVE WORKED LESS CONSERVATIVE SETPOINT DOES NOT AFFECT EQ PROFILES FULLY INDEPENDENT HIGH TEMPERATURE LOGIC AVAILABLE NO SAFETY FUNCTION LOST NO TECHNICAL SPECIFICATION LCOs EXCEEDED o RESOLUTION AS BUILT THE APPROPRIATE INSTRUMENT LINES IN NEXT REFUELING OUTAGE AND DETERMINE ANY NECESSARY ADDITIONAL ACTIONS

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 SILICON BRONZE BOLT ISSUES o PROBLEM: FAILURE OF SILICON BRONZE BOLTS IN SAFETY-RELATED MOTOR CONTROL CENTERS (MCCs),

o QUESTIONS: 1. DID WE EXCEED ANY ACTION STATEMENTS?

NO

2. WERE THE SAFETY FUNCTIONS PRESERVED?

YES

3. WHAT WAS THE SAFETY SIGNIFICANCE?

JANUARY 1986: NONE NOVEMBER 1986: MINIMAL

- FEBRUARY 1988: SIGNIFICANT o CHRONOLOGY OF EVENTS:

WILL DEMONSTRATE THAT CP&L TOOK APPROPRIATE CORRECTIVE ACTION BASED ON THE FACTS KNOWN AT THE TIME.

o ISSUES: -

WHILE APPROPRIATE CORRECTIVE ACTIONS WERE TAKEN, THERE WERE SOME INEFFICIENCIEG WHICH OCCURRED. THESE WILL BE ADDRESSED.

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CHRONOLOGY OF EVENTS o JANUARY 1986:

THREE 1/2" SBCH BOLTS FOUND BROKEN.

SHIPPING SPLITS ROUTINE PM BY MAINTENANCE MISAPPLICATION TECHNICAL SUPPORT INSPECTS SHIPPING SPLITS OF REMAINING SAFETY-RELATED MCCs.

SIX MORE 1/2" SBCH FOUND. (NOT BROKEN)

ROOT CAUSE: OVERT 0RQUING

- SHOULD HAVE BEEN STEEL

- MI TORQUE SPEC FOR STEEL o REMAINDER OF 1986:

1 16 TOTAL SBCH BOLTS FOUND FAILED l

THREE 1/2" IN SHIPPING SPLITS THIRTEEN 5/16" IN VERTICAL-TO-HORIZONTAL BUS BAR CONNECTIONS I

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CHRONOLOGY OF EVENTS (CONTINUED)  ;

i PROBLEM BEllEVED TO BE OVERT 0RQUING.

INITIATED DETAILED STUDY TO CORRELATE  :

VITH MAINTENANCE AND CONSTRUCTION DATA.

RESULTS IN NOVEMBER 1986.  ;

STUDY DID RQI CORRELATE OVERT 0RQUING ON 5/16" SBCH BOLTS.

SAFETY SIGNIFICANCE DEEMED MINIMAL AS:

16 FAILURES TO DATE OUT OF THOUSANDS.

N0 SAFETY FUNCTION IMPAIRED.

HOWEVER, RECOMMENDED REPLACING 5/16" SBCH BOLTS IN SAFETY-RELATED MCCs AT THE VERTICAL-TO-HORIZONTAL BUS BAR CONNECTIONS.

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 i

i CHRONOLOGY OF EVENTS (CONTINUED) 1 o 1987: MAINTENANCE PERFORMS ROUTINE PMs THROUGHOUT THE I YEAR. l l

1 REPLACING 5/16" SBCH BOLTS AT VEP.TICAL-TO- l HORIZONTAL BUS BAR CONNECTIONS (BOTH SAFETY I RELATED AND BOP).

- 0F ABOUT 15 MCCs WORKED, FOUND 12 ADDITIONAL BROKEN BOLTS, I

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CAROLINA POWER & L!GHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CHRONOLOGY OF EVENTS (CONTINUED)

JANUARY 1988: -

DUAL-UNIT OUTAGE TOTAL BROKEN B01TS SO FAR:

i THREE 1/2" SBCH (SHIPPING SPLITS)

TWENTY-FIVE 5/16" SBCH (VERTICAL-TO- ,

HORIZONTAL)

MAINTENANCE CORilNUES TO PERFORM ROUTINE PMs DURING OUTA66.

NINETEEN FAILURES IN ONE MCC FOUND ON JANUARY 20.

PLANT GENERAL MANAGER ORDERS INSPECTION OF l

SWITCHB0ARDS AND A GE AND HARRIS NETALLURGICAL LAB FAILURE ANALYSIS, ,

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1983 CHRONOLO6Y OF EVENTS (CONTINUED) (

RESULTS (FEBRUARY 17) ,

12/54 BROKEN 5/16" SBCH BOLTS 12/54 BROKEN 5/16" SBCH BOLTS 10/54 BROKEN 5/16" SBCH BOLTS 19/54 BROKEN 5/16" SBCH BOLTS IMMEDIATE SAFETY SIGNIFICANCE RESOLVED AS BOLTS REPLACED.

o APRIL 1988: -

GE AND HARRIS METALLURGICAL LAB REPLY THE FAILURE MECHANISM IS IGSCC. CONTAMINANT NOT XNOWN.

TECHNICAL SUPPORT PULLS 5/16" SBCH BOLTS REPLACED 22 MONTHS PREVIOUSLY TO ASSESS.

TWO 5/16" SBCH FOUND BROKEN COMMUNICATED TO NRC SENIOR RESIDENT DEVELOP SCHEDULE TO REPLACE WITH SH EL (MAY 3 TO JUNE 17) f

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEFTEMBER 8, 1988 1

CHRONDLOGY OF EVENTS (CONTINUED) o MAY 1988: -

TS INSPECTION REVEALS ADDITIONAL 5/16" SBCH BOLTS IN SHIPPING SPLITS AND 1/2" + 5/16" SBCH BGLTS IN WRAP-A-ROUNDS.

SCHEDULE ACCELERATED TO FINISH PRIOR TO UNIT 2 STARTUP.

COMPLETED IN MAY OR EVALUATED AS NO SAFETY SIGNIFICANCE.

HEX-HEAD SAMPLING PROGR.AM INITIATED AS ROOT CAUSE (CONTAMINANT) NOT DETERMINED; HOWEVER, N0 FAILURES SEEN TO DATE.

o JUNE 1988: -

CONDUCTING HEX-HEAD SAMPLING PROGRAM.

DISCOVERED 5/16" SBCH BOLTS IN THE GROUND SPLICES.

EVALUATED AND NO SAFETY SIGNIFICANCE.

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CAROLINA POWER & LIGHY COMPANY BRUNSWitK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE

, SEPTEMBER 8, 1938 ISSUES o CARRIAGE HEAD VS. HEX-HEAD SillCON BRONZE BOLTS HAD NOT SEEN ANY HEX-HEAD FAILURES; THEREFORE, EXCLUDED.

BOLT LAPPING LESS SEVERE FOR HEX-HEAD.

- AS ROOT CAUSE NOT KNOWN, WILL CONTINUE TO REPLACE WITH STEEL AND SAMPLE REMAINING ACCESSIBLE SILICON BRONZE BOLTS IN THE MCC'S AS WELL AS DEVELOP AIR SAMPLING INSIDE THE MCCs.

o SCOPE N0 INTERNAL DRAWINGS EXIST FOR THE MCCs.  ;

GE DOES NOT HAVE THE DRAWINGS.  :

- THEREFORE, PREPLANNING VERY DIFFICULT.

- LJT, COULD HAVE BEEN BETTER SCOPED ONCE WENT INTO THE MCCs DURING T!IE DUAL-UNIT OUTAGE.  !

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CHRONOLOGY OF EVENTS (CONTINUED) o TODAY -

SAMPLING PROGRAM COMPLETED.

NO HEX-HEAD FAILURES ,

MAINTENANCE REPi c.IN.' 't ACCESSIBLE SillCON BRONZE but-' . SIEEL.

TECHNICAL SUPPORT DEVELOPING ONGOING SAMPLING PROGRAM TO 11CLUDE:

ANALSIS BY HARRIS METALLURGICAL LAB 0F PULLED BOLTS, AND AIR SAMPLING ANALYSIS INSIDE MCCs.

CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 ISSUES (CONTINUED) o COMMUNICATIONS INTRAPLANT FELT TO BE POOR. ENHANCING SYSTEM ENGINEERING CONCEPT f TO ASSUME LEAD ROLE IN PROBLEM INVESTIGATION.  ;

PLANT TO NRC BELIEVE COMMUNICATIONS APPROPRIATE BUT CAN BE IMPROVED, o ROOT CAUSE ANALYSIS SHOULD HAVE BEEN PURSUED MORE AGGRESSIVELY. l A STRENGTHENED CORRECTIVE ACTION PROGRAM SHOULD IMPROVE.

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CORRECTIVE ACTIONS o SBCH BOLTS REPLACED WITH STEEL IN MCCs. [

- IF NOT REPLACED, ANALYZED AS OK.

o AS ROOT-CAUSE ANALYSIS NOT KNOWNa CONTINUE TO REPLACE SBHH BOLTS WITH STEEL.

ESTABLISH ONGOING SAMPLING PROGRAM BY 9/30/88.

ESTABLISH MECHANISM FOR MCC AIR SAMPLING BY 10/31/88.

o ONG0ING ENHANCEMENTS TO THE SYSTEM ENGINEERING FUNCTION-SYSTEM ENGINEER 1R CHARGE OF PROBLEM RESOLUTION UNLESS l

FORKALLY TURNED OVER TO ANOTHER GROUP WITH PLANT [

GENERAL MANAGER CONCURRENCE.

IMPROVE TRENDING EVALVATIONS SO SYSTEM ENGINEER IS AWARE OF ADVERSE TRENDS (1.E., ROUTINE TROUBLE TICKET REVIEWS),

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 CORRECTIVE ACTIONS (CONTINUED) o IMPROVEMENTS UNDERWAY TO CORRECTIVE ACTION PROGRAMS:

BETTER FOCUS ON ROOT CAUSE IMPROVEMENT IN PLANNING PROCESS '

DEMANDING INCREASED RESPONSIVENESS TO OUTSTANDING l ACTION ITEMS AND PROBLEMS FOUND IN THE FIELD, j i ,

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 l

SUMMARY

t o NO ACTION STATEMENT EXCEEDED o SAFETY FUNCTION OF EQUIPMENT PRESERVED o CP&L TOOK APPROPRIATE CORRECTIVE ACTIONS BASED ON THE FACTS KNOWN AT THE TIME

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i o INEFFICIENCIES DID OCCUR AND THESE ARE BEING AGGRESSIVELY  ;

PURSUED l

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CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT ENFORCEMENT CONFERENCE SEPTEMBER 8, 1988 I

[LQSING REMARKS l

I. CP&L APPRECIATES THIS OPPORTUNITY TO PRESENT ITS O',1N ASSESSMENT OF THE DC MOTOR, 300% STEAM FLOW SETPOINT, AND SILICON BRONZE BOLT ISSUES.

ALTHOUGH CP&L HAS ITS OWN VIEW 0F THE REGULATORY VULNERABILITY IT HAS INCURRED IN EACH OF THESE ISSUES, PRINCIPAL CONCERN IS TO LEAVE HERE WITH THE REGULATOR FEELING THAT CP&L IS PURSUING PROPER AND PRUDENT CORRECTIVE ACTIONS IN A TIMELY FASHION.

111. WE WISH TO ASSURE YOU THAT THE MANAGEMENT OF THE BRUNSWICK  :

PROJECT AND POWER PLANT IS TOTALLY COMMITTED TO SAFE, CORRECT, AND RELIABLE OPE' RATION OF THE POWER PLANT,

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