ML20196A441
| ML20196A441 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 11/25/1988 |
| From: | Ernst M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Tucker H DUKE POWER CO. |
| References | |
| NUDOCS 8812060008 | |
| Download: ML20196A441 (62) | |
See also: IR 05000369/1988024
Text
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NOV 2 51988
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Docket Nos. 50-369, 50-370
License Nos. NPF-9 NPF 17
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Duke Power Company
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f ATTN: Mr. H. B. Tucker, Vice President
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Nuclear Production Department
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422 South Church Street
Charlotte, NC 28242
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Gentlemen:
SUBJECT:
ENFORCEMENT CONFERENCE SUMMARY
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(NRC INSPECTION REFORT NOS. 50-369/88-24, 50-370/88-24 AND
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50-369/88-29,50-370/38-P.9)
This letter refers to the Enforcement Conference held at our request on
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October 27, 1988.
This meeting concerned activities authorized for your
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McGuire facility.
The issues discussed at this conference related to
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operability of the Hyrdrogen Skimmer (VX) system and inoperability c? safety
systems due to inadequate post modification testing.
A brief sumary, a list
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of attendees, and a copy of your handout are enclosed.
We are continuing our
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review of these issues to determine the approp"fate enforcement action.
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In accordance with Section 2.790 of the NRC's "Rules of Practice," Part 2,
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T1tle 10, Code of Federal Regulations, a copy of this letter and its enclosures
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will be placed in the NRC Public Document Room.
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Should you have any questions concerning this matter, please contact us.
Sincerely,
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(Original signed by M. Ernst)
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Malcolm L. Ernst
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Acting Regional Administrator
Enclosures:
1.
Enforcement Conference Sumary
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2.
List of Attendees
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3.
Handout
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W . 1. McConnell, Station Manager
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Jenior Resident inspector - Catawba
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State of North Carolina
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(See page 2)
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Duke Power Company
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NRu Resident Inspector
Das Technical A:sistant
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Docun>ent Con *.rol Desk
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ENCLOSURE 1
4
ENFORCEMENT CONFERENCE SU N RY
On October 27, 1988, representatives from Duke Power Company (OPC) met with the
NRC in the Region !! office in Atlanta, Georgia to discuss operability of the
Hydrogen Skimmer (VX) system and the inoperability of sefety systems due to
inadequate post modification testing.
Following opening remarks by J. P. Stohr
NRC, Ri! Acting Deputy Regional
Administrator, DPC gave two presentations (see Enclosure 3) which addressed NRC
concerns on the subjects listed above.
On the VX system, in addition to
covering a system overview, a sequence of events, and causes and contributing
factors, DPC addressed specific NRC concerns regarding preoperational testing
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of the VX system, a decision to enter Mode 4 on Unit 2 with VX flows below that
given in the FSAR, and OPCs operability determination process.
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presentation on the post modification testing program covered an
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overview / sequence of events, a safety analysis of each of the valves found to
have problems, and corrective actions to enhance DPCs post maintenance / post
modification testing program.
The NRC is presently considering enforctment action on these issues.
This
meeting served to enhance Region II's understanding of the issues and DPCs
corrective actions.
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ENCLOSURE 2
LIST OF ATTENDEES
U.S. Nuclear Regulatory Coninission
J. P. Stohr, Acting Deputy Regional Administrator
C. W. Hehl, Deputy Director, Division of Reactor Projects (DRP)
A. F. Gibson, Director, Division of Reactor Safety (DRS)
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E. W. Merschoff, Deputy Director, DRS
G. R. Jenkins, Director, Enforcement and Investigation Coordination Staff
(EICS)
V. L. Brownlee, Branch Cr'ef DRP
D. Hood, McGuire Projec ..anager, Office of Nuclear Reactor Regulation (NRR)
F. Jape, Section Chief, uRS
W. T. Orders. Senior Resident Inspector, Catawba, DRP
B. R. Bonser, Project Engineer, DRP
F. K. VanCO)rn, Senior Resident Inspector, McGuire, DRP
D. J. Nelsen, Resident Inspector, McGuire DRP
,
R. P. Croteau, Resident inspector, McGuire, DRP
B. Uryc, Enforcement Coordinator, EICS
Duke Power Company
H. B. Tucker Vice President, Nuclear Production
T. L. McConnell, Station Manager, McGuire
N. Rutherford, Manager, Licensing
B. H. Hamilton, Superintendent of Technical Services. McGuire
W. M. Sample, Superintendent of Maintenance, McGuire
R. O. Sharpe, Compliance Engineer
B. L. Peele, Principal Engineer, Design Engineering
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ENCLOSURE 3
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DUKE POWER COMPANY /NRC
ENFORCEMENT CONFERENCE
OCTOBER 27, 1988
VX OPERABILITY
1.
INTRODUCTORY REMARKS
T. L. McCONNELL
11. OVERVIEW
T.
L. McCONNELL
lli. SEQUENCE OF EVENTS
B. H. HAMILTON
IV. ROOT CAUSE AND CONTRIBUTING FACTORS
B. H. HAMi LTON
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V. CONCERNS TO BE ADDRESSED
B . H . HAM I LTON
A.
PREOPERATIONAL TESTING OF VX SYSTEM
B. H. HAMILTON
B.
DECISION TO ENTER MODE 4
B. H. HAMILTON
C.
DPCo OPERABILITY DETERMINATION PROGRAM
B. H. HAMILTON
D.
SAFETY ANALYSIS
B. L. PEELE
IV. SUMMARY
T.
L. McCONNELL
FUNCTIONAL VERIFICATION PROBLEMS
1. OVERVIEW
T.
L. McCONNELL
11. SEQUENCE OF EVENTS
T.
L. McCONNELL
lit. ROOT CAUSE/ CORRECTIVE ACTIONS
W.
M.
SAMPLE
IV. SAFETY SIGNIFICANCE
W.
M. SAMPLE
V. SUMMARY STATEMENT
T.
L. McCONNELL
CLOSING REMARKS
T.
L. McCONNELL
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VX OPERABILITY
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OVERVIEW
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SEE ATTACHED SIMPLIFIED SCHEMATIC OF THE VX SYSTEM (HYDROGEN
SKIMMER PORTION ONLY).
UNIT 1
DURING A UNIT 1 CONTAINMENT CLOSEOUT INSPECTION IN NOVEMBER OF
1987, NRC PERSONNEL NOTICED THAT A HYDROGEN SNIMMER (VX)
SYSTEM DAMPER APPEARED TO BE CLOSED.
OPERATIONS PERSONNEL
INSPECTED AND VERIFIED THAT EACH VX SYSTEM DAMPER WAS IN ITS
CORRECT PRE-OPERATIONAL POSITION WITH THE EXCEPTION OF ONE DAMPER
QUESTIONED BY THE NRC INSPECTOR.
THE CORRECT POSITION 'dAS
VERIFIED BY PAINT SHADOWS ON THE DAMPER ACTUATORS CREATED PRIOR
TO UNIT 1 CRITICALITY.
THE QUESTIONED DAMPER WAS ONLY SLIGHTLY
MISPOSITIONED IN THE CLOSED DIRECTION.
SINCE THERE WAS NO PROCEDURE TO ASSURE PROPER DAMPER POSITIONS ON
THE VX SYSTEM, NRC PERSONNEL WERE CONCERNED ABOUT THE UNIT 2
DAMPER POSITIONS.
STATION PERSONNEL AGREED TO DO VX FLOW BALANCE
TESTS FOR BOTH UNITS DURING THElR NEXT REFUELING OUTAGES.
UNIT 2
AT THE END OF THE JULY 1988 REFUELING OUTAGE, PERFORMANCE
PERSONNEL TOOK "AS FOUND" FLOW MEASUREMENTS USING A HAND HELD
VELOMETER ON BOTH TRAINS OF THE UNIT 2 VX SYSTEM.
SOME VX SYSTEM
DAMPER COMPARTMENT FLOWS DID NOT MEET FSAR REQUIREMENTS AND TWO
DAMPERS, BOTH SERVING THE REACTOR HEAD AREA, WERE FOUND CLOSED,
ALL DAMPERS WERE ADJUSTED IN AN ATTEMPT TO ACHIEVE FLOW RATES
LISTED IN THE FSAR.
THIS WAS UNSUCCESSFUL BECAUSE SETTING THE
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HYDROCEN SKINMER
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AND CONTAINMENT AIR RETURN SYSTEM (VI)
PRESENT ARRANCEMENT
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DAMDERS FOR ONE TRAIN TO MEET FSAR FLOWS WOULD CAUSE FLOW RATES
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FOR THE OTHER TRAIN TO Fall THE FSAR FLOW REQUIREMENTS.
FINAL
FLOWS WERE MEASURED WITH A VELOMETER AND LATER TRAIN A FLOWS WERE
CONFIRMED WITH THE MORE ACCURATE FLOW HOOD.
DESIGN ENGINEERING
(D.E.) PERSONNEL THEN BEGAN AN EVALUATION ON THE NEW VX SYSTEM
FLOW RATES.
PLANT PERSONNEL TERMINATED THE FLOW BALANCE TEST USING THE MORE
ACCURATE FLOW HOOD BEFORE COMPLETING TESTING ON TRAIN B OF THE VX
SYSTEMS AND UNIT 2 ENTERED MODE 4 BASED ON A VERBAL OPERABILITY
DETERMINATION FROM D.E.
RATIONALE FOR THIS DECISION WILL BE
DISCUSSED LATER.
LATER THAT DAY, D.E.
ISSUED A WRITTEN
OPERABILITY DETERMINATION FOR VX BASED IN PART ON THE
AVAILABILITY OF THE OPERABLE HYDROGEN MITIGATION SYSTEM TO
SUPPORT THE OPERABILITY OF THE VX SYSTEM.
IN THClR REVIEW THE
NEXT WEEK, THE NRC JUDGED THE OPERABILITY DETERMINATION BASED ON
THAT ASSUMPTION TO BE INADEQUATE.
WE AGREE WITH THi NRC
DETERMINATION.
PERFORMANCE PERSONNEL COMPLETED THE ACCESSIBLE COMP /RTMENT FLOW
MEASUREMENTS ON TRAIN B OF THE VX SYSTEM USING THE MORE ACCURATE
FLOW HOOD DEVICE.
A NEk UNIT 2 OPERABILITY DETERMINATION WAS
ISSUED BY D.E.
IT CONCLUDED THAT THE PRESENT FLOW BALANCE
CONDITION OF THE VX SYSTEM WAS SUFFICIENT AND WAS CONSIDERED
THE NRC HAS SUBSEQUENTLY REVIEWED THIS OPERABILITY
STATEMENT AND HAS AGREED WITH iT.
UNIT 1 FOLLOW-UP
IMMEDIATELY AFTER SHUT 10WN FOR THE CURRENT UNIT 1 OUTAGE, ALL
DAMPERS WERE VERIFIED OPEN AND THElR POSITIONS WERE MARKED.
THE
UNIT 1 VX FLOW BALANCE TEST WAS CONDUCTED USING THE FLOW HOOD
METHOD.
ALL FLOWS MET THE NEW ACCEPTANCE CRITERIA DEVELOPED
EXCEPT FOR TRAIN A OF THE PRESSURIZER CAVITY AND BOTH TRAINS OF
THE REACTOR HEAD AREA.
THE IMPACT OF THESE LOW FLOWS WILL BE
DISCUSSED LATER.
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VX OPERABILITY
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SEQUENCE OF EVENTS
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EVENT
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NRC PERSONNEL NOTICED THAT SOME UNIT 1 VX
11/08/87
SYSTEM DAMPERS APPEARED TO BE CLOSED.
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NRC PERSONNEL QUESTIONED OPS PERSONNEL ABOUT
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THE POSITIONS OF THE UNIT 1 VX SYSTEM DAMPERS.
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OPS PERSONNEL VERIFIED THAT EACH UNIT 1 VX
11/09/87
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SYSTEM DAMPER WAS IN ITS PRE-OPERATIONAL
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POSITION AS EVIDENCED BY PAINT SHADOWS ON THE
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DAMPER ACTUATORS.
ONE DAMPER WAS MISPOSITIONED
IN THE CLOSED DIRECTION.
IT WAS RETURNED TO
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ITS PROPER POSITION,
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NRC PERSONNEL WERE CONCERNED ABOUT THE POSI-
TlONS OF THE UNIT 2 VX SYSTEM DAMPERS, AND
CONSEQUENTLY, STATION PERSONNEL AGREED TO DO A
VX FLOW BALANCE TEST FOR EACH UNIT DURING THEIR
NEXT REFUELING OUTAGES.
PERFORMANCE PERSONNEL TOOK "AS FOUND" FLOW
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7/19/88
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MEASUREMENTS USING A VELOMETER ON BOTH TRAINS
OF UNIT 2 OF THE VX SYSTEM.
SOME VX SYSTEM
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DAMPER COMPARTMENT FLOWS DID NOT MFfT THE
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MCGUIRE FINAL SAFETY ANALYSIS REPr.RT (FSAR)
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REQUIREMENTS AND TWO DAMPERS SERVING THE
REACTOR HEAD AREA WERE FOUND CLOSED.
DESIGN
ENGINEERING WAS NOTIFIED OF THESE FINDINGS.
DESIGN ENGINEERING REQUESTED MORE ACCURATE
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7/20/88
MEASUREMENTS BE TAKEN USING A FLOV HOOD.
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7/21/88
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PERFORMANCE PERSONNEL BEGAN THE RF. TEST OF THE VX
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2A SYSTEM USING A FLOW HOOD.
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THE TRAIN A VX RETESTS WERE COMPLETED AND
TRAIN 2B RETESTS WERE BEGUN.
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DESIGN ENGINEERING PERSONNEL REEVALUATED THE VX
SYSTEM FLOW RATES THAT WERE LISTED IN THE FSAR.
THEY EXPRESSED CONFIDENCE THAT THEY COULD
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PROVIDE A TECHNICAL JUSTIFICATION FOR THE
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OPERABILITY OF THE VX SYSTEM.
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PLANT PERSONNEL TERMINATED THE 2B VX FLOW
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BALANCE TEST BEFORE IT WAS COMPLETED.
THIS WAS
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A MANAGEMENT DECISION WAS BASED UPON D.E.
INPUT
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TilAT FINAL B TRAIN NUMBERS WERE NO LONGER
ESSENTIAL AND ALL THE INFORMATION REQUIRED FOR
THE OPERABILITY DETERMINATION HAD BEEN
GATHERED.
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STATION MANAGEMENT COMMUNICATED THE DECISION
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TO TERMINATE THE 2BVX FLOW BALANCE TEST TO THE
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NRC RESIDENT INSPECTOR AS A COURTESY.
THE
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OPERABILITY DETERMINATION WAS STATED AS THE
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REASON, HOWEVER, SPECIFICS WERE NOT DISCUSSED
AT THIS TIME.
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STATION MANAGEMENT REVIEWED DRAFT OF DESIGN'S
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VX OPERABILITY DETERMINATION AND EVALUATION.
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AFTER INITIAL DISCUSSION VERBAL AGREEMENT WAS
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REACHED WITH DESIGN.
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UNIT 2 ENTERED MODE 4 PER MANAGEMENT DECISION.
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DESIGN ENGINEERING PERSONNEL ISSUED THE SIGNED
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7/22/88
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OPERABILITY DETERMINATION BASED IN PART ON THE
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OPERABILITY OF THE HYDROGEN MITIGATION SYSTEM.
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AFTER FURTHER REVIEW, THE NRC PERSONNEL JUDGED
8/1/88
THE UNIT 2 OPERABILITY DETERMINATION TO BE
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INADEQUATE BECAUSE DESIGN ENGINEERING PERSONNEL
TOOK CREDIT FOR THE HYDROGEN MITIGATION SYSTEM
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TO SUPPORT THE VX SYSTEM OPERABILITY
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DETERMINATION.
8/2-15/88 ----
DESIGN ENGINEERING PERSONNEL BEGAN
REEVALUATING THE VX SYSTEM FLOW RATES IN A
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MANNER CONSISTENT WITH REGULATORY GUIDE 1.7,
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REVISION 2, AND 10CFR50.44, WHICH REDUCED THE
REQUIRED FLOW RATES FOR THE VX SYSTEM.
PERFORMANCE PERSONNEL COMPLETED ON-LINE FLOW
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8/16/88
MEASUREMENTS ON ACCESSIBLE PORTIONS OF TRAIN B
OF THE VX SYSTEM USING THE FLOW HOOD.
THIS WAS
DOME TO EVALUATE BOTH TRAINS AGAINST THE NEW
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ACCEPTANCE CRITERIA UNDER DEVELOPMENT.
DESIGN ENGINEERING PERSONNEL ISSUED A NEW UNIT
8/19/88
2 OPERABILITY DETERMINATION AND CONCLUDED THAT
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THE PRESENT FLOW BALANCE CONDITION OF THE VX
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SYSTEM WAS SUFFICIENT AND WAS CONSIDERED
THIS CONCLUSION ALSO APPLIES TO THE
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OPERABILITY OF THE SYSTEM ON 7/21/88 WHF.N MODE
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4 WAS ENTERED.
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A MCGuinE NRC RESIDENT INSPECTOR NOTIFIED
9/16/88
STATION MANAGEMENT THAT NRC HAD FULLY REVIEWED
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AND ACCEPTED THE OPERABILITY STATEMENT AND
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EVALUATION.
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PERFORMANCE PERSONNEL ENTERED THE UNIT 1
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REACTOR BUILDING IMMEDIATELY AFTER S/D AND
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VERIFIED THE DAMPERS IN THE UPPER HEAD AND
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PRESSURIZER AREAS WERE OPEN AND MARKED THEIR
POSITION.
THIS WAS DONE TO ENSURE "AS FOUND"
DATA.
THESE ARE HIGH TRAFFIC AREAS DURING AN
OUTAGE.
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PERFORMANCE PERSONNEL CONDUCTED THE UNIT 1 VX
10/18/88
FLOW BALANCE TEST USING THE FLOOD HOOD METHOD.
ALL FLOWS MET THE NEW ACCEPTANCE CRITERIA
DEVELOPED IN THE 8/19/88 OPERABILITY
DETERMINATION WITH THE EXCEPTION OF "A" TRAIN
PRESSURIZER CAVITY AND BOTH TRAINS IN THE
REACTOR HEAD AREA.
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ROOT CA'USE
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WO PROBLEMS EVENTUALLY LED TO THIS SITUATION:
(1) THE PREOPERATIONAL TEST PERFORMED ON THE VX SYSTEM WAS
INSUFFICIENT TO PROVE OPERABILITY. THE STATION PERSONNEL'S
DEGREE OF UNDERSTANDING OF THE SYSTEM AND OUR DEPENDENCE UPON
PREVIOUSLY AGREED UPON TESTING COMMITNENTS LED US TO OMIT
FLOW BALANCE TESTING OF THIS SYST M FROM THE PREOPERATIONAL
TEST FROGRAM.
(2) APPROPRIATE MEASURES WERE NOT TAKEN TO ENSURE THE FLOW
BALANCE OF THIS SYST m WAS MAINTAINED EITHER THROUGH PF.RIODIC
TESTING OR CONTROL OF DAMPER POSITIONS.
CONTRIBUTING FACTOR
BY DESIGN, THE VX SYSTEM !!AS A SINGLE HEADER THAT DRAVS AIR FROM
EACH OF THE CONTAINMENT COMPARTMENTS BY USE OF REDUNDANT FANS
LOCATED ON EITHER END OF THE HEADER. EITHER FAN IS CAPABLE OF
DRAWING THE TOTAL DESIGN BASIS FLOWS FROM THE AREAS SERVICED.
HOWEVER. THE EQUIPMENT CONFIGURATION OF THE SYSTEM IS SUCH THAT
BALANCE OF THE INDIVIDUAL COMPARTMENT FSAR FLOW RATES IS
UNOBTAINABLE WHEN OPERATING THE FANS INDEPENDENTLY. THE SYSTEM IS
BEING MODIFIED TO CORRECT THIS DEFICIENCY.
SUBSEQUENT TESTING
WILL VALIDATE THE NEW DESIGN.
A.
PREOPERATIOJAL TESTING OF THE VX SYSTDI
1.
UNIT #1
THE ORIGINAL PREOPERATIONAL TEST PREPARED AND PERFORMED FOR
UNIT #1 WAS BASED ON THE CHAPTER 14 FSAR ABSTRACT.
THE
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ABSTRACT INCLUDED NO PROVISIONS FOR FLOW BALANCING THE SYSTEM
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AND NO BALANCE WAS PERFORMED. STATION PERSONNEL ASSUMED THAT
THE HVAC VENDOR HAD BALANCED THE SYSTEM. THIS WAS THE NORMAL
PRACTICE FOR HVAC SYSTEMS. THIS SYSTEM WAS DIFFERENT. THE
HVAC VENDOR WAS NOT ASSOCIATED WITH THE SUCTION RING HEADER.
LATER IN UNIT #1'S PREOPERATIONAL TEST:lNG, THE PROPER
POSITIONING OF CERTAIN DAMPERS OF THE VX SYSTEM WAS
QUESTIONED.
IN ORDER TO RESOLVE THESE QUESTIONS PLANT
PERSONNEL CONDUCTED A FLOW BALANCE.
THE FLOW BALANCE WAS
INADEQUATE AS A RESULT OF BOTH TRAINS BEING OPERATED
SIMULTANEOUSLY. THIS FLOW BALANCE WAS DOCUMENTED IN A
3/23/81 MEMORANDUM TO FILE AND WAS NOT PART OF THE
PREOPERATIONAL TEST PROGRAM.
IT WAS DONE TO ANSWER SYSTEM
OPERABILITI QUESTIONS.
IT WAS STILL ASSUMED THE HVAC VENDOR
HAD PROPERLY BALANCED THE SYSTEM.
2.
UNIT 2
AFTER REVIEWING THE UNIT 2 PREOPERATIONAL TESTING FOR THE VX
SYSTEM, IT IS DIFFICULT TO DETERMINE EXACTLY WHAT WAS DONE IN
REGARDS TO FLOW BALANCING THE SYSTEM. AGAIN HEAVY DEPENDENCE
WAS PLACED UPON THE HVAC VENDOR PROPERLY BALANCING THE
SYSTEM. WITHOUT FURTHER 'INFORMATION WE CAN ONLY CONCLUDE
THE "A" TRAIN WAS BALANCED. HOWEVER, THE RESULTS ARE NOT
CONSISTENT WITH CURRENT PERFORMANCE OF THE SYSTEM. THOSE
INVOLVED WITH THE UNIT 2 TESTING ARE NO LONGER WITH DUKE
POWER COMPANY AND FOR THIS REASON FURTHER INVESTIGATION IS
RESTRICTED.
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3.
INADEQUACY OF THE VX PREOPERATIONAL TEST
.
AT THE TIME OF OUR PREOPERATIONAL TEST PROGRAM, OUR PRIMARY
EMPHASIS WAS ON ECCS SYSTEMS. THE TEST PROGRAM FOR BALANCE
OF PLANT, SAFETY RELATED SYSTEMS WAS NOT AS CAREFULLY
SCRUTINIZED. THIS WAS TRUE OF THE HVAC SYSTEMS WHERE TWO
FACTORS COMBINED TO INHIBIT PROPER TESTING. THE FIRST FACTOR
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WAS THE CLARITY AND AVAILABILITY OF DESIGN BASIS INFORMATION
ON THESE PARTICULAR SYSTEMS. THE OTHER FACTOR WAS THE
DEPENDENCE ON THE HVAC VENDOR FOR SYSTEM START UP.
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ANOTHER FACTOR LEADING TO THE INADEQUATE PREOPERATIONAL TEST
ON THE VX SYSTEM WAS THE FAILURE TO INCLUDE FLOW BALANCE
REQUIREMENTS IN CHAPTER 14 0F THE FSAR. DURING THIS TIME
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PERIOD CHAPTER 14 0F THE FSAR AND THE TECHNICAL
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SPECIFICATIONS WERE USED AS THE PRIMARY SOURCE OF TESTING
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COMMITMENTS. AT THE TIME OUR PREOPERATIONAL TEST PROGRAM WAS
CONDUCTED WE DID NOT PROGRAMATICALLY LOOK BEYOND THESE
DOCUMENTS FOR OTHER TESTING REQUIREMENTS.
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4.
CORRECTIVE ACTIONS
SPECIFICALLY FOR THE VX SYSTEM:
WE WILL MODIFY THE SYSTEM TO ENRANCE OUR ABILITY TO
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BAIANCE THE SKIMMER FLOWS.
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WE WILL CONDUCT A TEST TO OPTIMIZE THE FLOW BALANCE
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OF THE VX SYSTEM.
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WE WILL ESTABLISH APPROPRIATE CONTROLS TO ENSLTE
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THE FLOW BALANCE IS MAINTAINED.
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HYDROCEN SKDGER
AND CONTAINNENT AIR RETVEN SYSTEM (VI)
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REVISED ARRANCEMENT
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s=>
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-. .
,
.
.
.
GENERIC ACTIONS:
.
UPON REVIEW WE HAVE CONCLUDED THE PREOPERATIONAL TEST
PROGRAM AT MCGUIRE MAY HAVE BEEN INADEQUATE FOR A
SPECIFIC CLASS OF SYSTEMS: THOSE BEING SAFETY RELATED,
BALANCE OF PLANT SYSTEMS.
IN ORDER TO ADDRESS THIS
CONCERN, WE ARE REVIEWING THE PREOPERATIONAL TESTING FOR
EACH OF T1'ESE SYSTD(S TO ENSURE IT WAS ADEQUATE.
IN
CONJUNCTION WITH THIS WE ARE EVALUATING THE SURVEILIANCE
TESTING CONDUCTED TO ENSURE IT IS SUFFICIENT TO ENSURE
CONTINUED OPERABILITY.
THIS REVIEW HAS BEGUN. THE AUXILIARY FEEDWATER SYSTEM
IS BEING USED AS A "PILOT" SYSTEM. AFTER THIS REVIEW IS
COMPLETE, A SCHEDULE WILL BE ESTABLISHED FOR ALL SYSTEMS
INVOLVED.
IT IS ANTICIPATED THE REVIEW WILL BE DONE BY
MAY OF 1989.
C.
DECISION TO ENTER MODE #4
1.
SITUATION ON JULY 21, 1988
THE VX FLOW BALANCE WAS PERFORMED AT THE END OF THE UNIT #2
REFUELING OUTAGE WHILE IN MODE #5.
IT WAS ONE OF MANY TESTS
PERFORMED, MOSTLY AS A RESULT OF MAINTENANCE AND
MODIFICATIONS, DURING THE LAST WEEKS OF THE OUTAGE. MOST OF
THESE TESTS, INCLUDING THE VX FLOW BALANCE, WERE REQUIRED TO
BE COMPLETED PRIOR TO MODE #4.
TESTING PERSONNEL HAD BEEN
MAINFAINING A VERY INTENSE SCHEDULE FOR APPROXIMATELY 2
WEEKS.
_ _ _ _ _ _ _ _ _ _ _ _
o
.
O
.
2 .'
PERSONS INVOLVED WITH THE DECISION
.
THE DECISION WAS MADE AT THE APPROPRIATE LEVEL OF MANAGEMENT.
THE SUPERINTENDENT OF OPERATIONS, MAINTENANCE. TECHNICAL
SERVICES, AND INTEGRATED SCHEDULING ALL WERE INVOLVED IN THE
DECISION. ALSO INVOLVED WERE THE DESIGN ENGINEERING SITE
OFFICE MANAGER AND OTHER MANAGEMENT PERSONS FROM THE
CORPORATE DESIGN ENGINEERING GROUP.
THE SENIOR RESIDENT INSPECTOR FOR THE NRC WAS MADE AWARE OF
THE DECISION AS A COURTESY.
HIS CONCURRENCE WAS NOT SOUGHT
OR OBTAINED. AT THE TIME THE DECISION WAS COMMUNICATED TO
THE SENIOR RESIDENT, DETAILS OF THE OPERABILITY DETERMINATION
WERE NOT YET AVAILABLE.
_
_ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _
.
,.
.
.
.
3.
FACTORS CONSIDERED IN THE DECISION
.
FOLLOWING THE COMMUNICATION OF TEST RESULTS TO THE CORPORATE
DESIGN ENGINEERING GROUP. THOSE INVOLVED AND RESPONSIBLE FOR
THE DESIGN OF THE VX SYSTEM WERE VERY CONFIDENT THAT THE VX
SYSTEM WOULD STILL PERFORM ITS DESIGN FUNCTION IN ITS
DEGRADED CONDITION. THESE DESIGN EXPERTS CLEARLY BELIEVED
THEY COULD PRESENT A TECHNICALLY CORRECT JUSTIFICATION FOR
THE OPERABILITY OF THE VX SYSTEM. AND EXPRESSED THIS
CONFIDENCE THROUGHOUT THE EVALUATION PERIOD.
THE FLOW BALANCE TESTING HAD GONE THROUGH SEVERAL
UNSUCCESSFUL ITERATIONS. THE ORIGINAL INTENT OF THE TEST HAD
BEEN TO BALANCE THE SYSTEM TO FSAR FLOW VALUES. WE HAD
DISCOVERED THIS WOULD NOT BE POSSIBLE. THE NEW PURPOSE HAD
BECOME TO GATHER ENOUGH DATA TO SUPPORT THE CORPORATE DESIGN
ENGINEERING GROUP'S EFFORT TO JUSTIFY THE OPERABILITY OF THE
VX SYSTM. ONCE THE DESIGN EXPERTS STATED THEY HAD
SUFFICIENT DATA TO SATISTY THIS NEED. FURTHER TESTING WAS
UNNECESSARY. THE LETERMINATION THAT SUFFICIENT DATA HAD BEEN
GATHERED OCCURRED DURING THE FLOW HOOD MEASURD(ENTS ON UNIT 2
"B" TRAIN. THUS A COMPLETE SET OF "B" TRAIN FLOW HOOD
MEASURD(ENTS WAS NOT TAKEN PRIOR TO ENTERING MODE #4.
STATION MANAGD(ENT'S DECISION TO PROCEED TO MODE #4 WAS
PRIMARILY BASED OP.4 INPUT FROM EXPERTS FAMILIAR WITH THE VX
SYSTEM. THESE EXPERTS CLEARLY BELIEVED THE SYSTEM WOULD
PERFORM ITS DESIGN FUNCTION. WITH THIS CONFIDENCE STATION
_ _ _ _ _ _ _ .
.
o
.
.
MANAGEMENT SAW NO REASON TO DELAY THE SCHEDULED START-UP OF
.
UNIT 2 FOLLOWING THE REFUELING OUTAGE.
4.
CORRECTIVE ACTIONS
ALTHOUGH THE OPERABILITY DETERMINATION OF 8/19/88 LATER
CONCLUDED THAT THE VX SYSTEM WAS CAPABLE OF PERFORMING ITS
DESIGN FUNCTION, THE DECISION TO PROCEED TO HODE I/4 ON
7/19/88 WAS BASED ON INCORRECT INFORMATION.
THE DECISION
ITSELF WAS NOT AT FAULT, BUT THE PROCESS BY WHICH IT WAS
ARRIVED AT HAD WEAKNESSES.
THE OPERABILITY DETFAMINATION
PROGRAM WILL BE STRENGTHENED TO HELP PRECLUDE ERRORS SUCH AS
THIS IN THE FUTURZ.
C. OPERABILITY DETERMINATION PROCESS
1.
THE VX OPERABILITY DETERMINATION BROUGHT SEVERAL CONCERNS TO
LIGHT INVOLVING DUKE POWER COMPANY'S JUSTIFICATION FOR
CONTINUED OPERATION /0FFRABILITY DETFAMINATION PROGRAM.
THESE
ARE SUMMARIZED HERE:
+
ALTHOUGH OPERABILITY DETERMINATIONS ARE DOCUMENTED IN
ACCORDANCE WITH ESTABLISHED PROCEDURES AND ARE
TYPICALLY TECHNICALLY STRONG. THEY DO NOT
PROGRAMATICALLY INCLUDE 10CFR50.59 EVALUATIONS.
6
No PROCEDURES EXIST FOR THE REVIEW AND APPROVAL OF
OPERABILITY DETFRMINATIONS BY NUCLEAR PRODUCTION
DEPARIMENT PERSONNEL.
(THE DESIGN ENGINEERING
__
_ _ _ _ _ _
.
,
'
.
DEPARTMENT PERFORMS INTERNAL REVIEWS.) AS A RESULT,
.
OPERABILITY DETERMINATIONS RECEIVE VARYING DEGREES OF
f
REVIEW AND APPROVAL.
l
'
4
NO PROCEDURES EXIST TO CONTROL OPERABILITY
DETERMINATIONS AND TRACK THDi ONCE THEY HAVE BEEN
'
ACCEPTED.
j
e
THE PROCESSES OF PERFORMING A JUSTIFICATION FOR
.
l
CONTINUED OPERATION (JCL), AN OPERABILITY DETERMINATION,
j
L
AND ANSWERING A PROBLD1 IDENTIFICATION REPORT (PIR) HAVE
,
!
BECOME INTERCHANGEABLE. THIS HAS APPARENTLY LED TO A
'
GREAT DEAL OF CONFUSION IN OUR COMMUNICATIONS WITH THE
!
NRC.
RECENT DISCUSSIONS WITH REGION II PERSONNEL HAVE
MORE CLEARLY ESTABLISHED THE DISTINCTIONS BEIVEEN THESE
PROCESSES.
i
,
2.
IN ORDER TO RESPOND TO THESE PROBLEMS, THE FOLLOWING CORRECTIVE
l
ACTIONS ARE BEING PLANNED. THESE CORRECTIVE ACTIONS WILL APPLY To
,
ALL 3 DUKE POWER COMPANY NUCLEAR FACILITIES.
(a.) OUR NUCLEAR PRODUCTION DEPARTNENT DIRECTIVE WILL BE REVISED
i
TO INCLUDE THESE UPGRADES:
,
e
THE JCO, OPERABILITY DETERMINATION, AND PIR RESPONSE
PROCESSES WILL BE CLEARLY DEFINED. EXPECTED LEVELS OF
[
l
NRC INVOLVEMENT WILL BE ESTABLISHED.
l
l
4
REQUIRDtENTS TO CONSIDER THE QUESTIONS ADDRESSED IN
l
10CFR50.59 WILL BE ESTABLISHED.
REVIEW RESPONSIBILITIES BY NUCLEAR PRODUCTION PERSONNEL
I
I
WILL BE ESTABLISHED, APPROVAL LEVELS WILL BE SET.
f
I
i
(
I
t
!
- -
-
__
e
e
4
(b.) PROCEDURES WILL BE ESTABLISHED AT THE STATION TO CONTROL AND
-
TRACK OPERABILITY DETERMINATIONS.
THESE UPGRADES ARE NOW IN PREPARATION AND ARE EXPECTED TO BE
COMPLETE IN THE FIRST QUARTER OF 198'd.
,
i
e
-
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
__
e
.
.
.
UNIT 1 HYDROGEN SKIMMER TAN COMPARTMENT FLOW MEASUREMENT
AS TOUND DATA
10/18/88
Required
compartments
riew
HSF-1A
HSF-18
SG-1A
121
214
916
50-1B
121
671
360
SG-1C
121
521
254
SG-1D
121
300
771
()
283
PZR
121
ACC-1A
4
46
37
ACC-1B
4
36
20
ACC-1C
24
68
86
ACC-1D
24
43
70
Inc. Rs.
15
138
107
(h)
(h)
Rx. Hd.
172
I.
Tan Rs.
29
71
68
W.
Tan Rs.
29
71
57
l
The above flows were measured per TT/1/A/9100/217 and are given
l
in SCTM.
Each of the thirteen compartments above is served by two intake
The "as-found" condition for each of the twenty-six
dampers was open or throttled.
Eight dampers (serving the S/Gs)
were 100% cpen, with remaining damper positions varied, throttled
closed by as much as 95%.
Total flow for each HSF was measured by traversing the suction
duct.
Results were
HSF-1A = 3307 SCTM;
HST-1B = 3212 ScrM.
[d /T
7
P. W.
Roberson
NP Engineer, Performance
j
file:dvx.dw4.vxflow.ul.101988
. .
__.
.
l
.
.
.
Table 14.1.3-1 (Page 30)
-
4
CONTAINMENT AIR RETURN AND HYDROGEN SKIMMER SYSTEM FUNCTIONAL TEST
Abstraa.t
Purpose
To descnstrate the capability of the system to operate and to provide design
air flows.
Prerequisites
The .cs condenser inlet doors are blocked closed to prevent operation.
Test Method
Each containment air return fan and hydrogen skimmer fan is operated.
Tests
are performed to demonstrate the proper head and flow characteristics of eacn
fan. Automatic operation of the Containment air return fans is verified for a
simulated high-high containment pressure signal (S ).
System interlocks are
P
also verified.
Acceptance Criteria
Each fan provides air flow as specified in the FSAR and the Containment air
return fans respond properly to a simulated high-high containment pressure
signal (S ).
p
,
O
,
12/83
'
!
..
e.
l
, .-
[
'
VX SAFETY ANALYSIS
-
!
i
!
INADEQUATE VX SYSTEM FLOWS (UNIT 2)
t
!
FLOW BALANCE TESTING PERFORMED DURING THE 1988 UNIT 2 REFUELING
I
OUTAGE BEGAN BY RECORDING "AS-FOUND" FLOW READINGS PRIOR TO
l
ADJUSTING THE BALANCING VALVES,
INLET VALVES FOR THE REACTOR HEAD
l
AREA WERE FOUND IN THE CLOSED POSITION, AND INITIAL' READINGS IN
!
FOUR (4) OTHER COMPARTMENTS WERE FOUND TO BE BELOW THE REVISED
[
MINIMUM FLOW REQUIREMENTS.
IN ADDITION TO THE REACTOR HEAD AREA,
j
THE FOUR (4) AREAS FOUND DEFICIENT IN FLOW WERE THE EAST FAN ROOM,
j
WEST FAN ROOM, ACCUMULATOR ROOM 2C, AND ACCUMULATOR ROOM 20.
!
I
THE AS-FOUND FLOW VALUES HAVE BEEN EVALUATED FOR SAFETY
(
SIGNIFICANCE REGARDING HYDROGEN ACCUMULATION.
THE EVALUATION
(
CONCLUDES THAT SINCE NONE OF THE AFFECTED COMFARTMENTS ARE TRULY
!
l
DEAD-ENDED REGIONS, THE CIRCULATION FORCED BY THE CONTAINMENT AIR
f
l
RETURN FANS ALONG WITH, IN THE CASE OF THE REACTOR HEAD AREA, THE
l
l
SIGNIFICANT NUMBER OF LARGE OPENINGS INSTALLED FOR PRESSURE RELIEF
.
PURPOSES, WOULD LIMIT HYDROGEN CONCENTRATION TO LESS THAN FOUR
j
l
l
VOLUME PERCENT.
l
1
.
FAN ROOMS AND THE AFFECTED ACCUMULATOR ROOMS SERVE AS THE DESIGN
i
t
FLOW PATH FOR THE CONTAINMENT AIR RETURN FANS IN ClRCULATING AIR
l
FROM THE UPPER CONTAINMENT TO THE LOWER CONTAINMENT A*' THROUGH THE
I
ICE CONDENSER.
EACH OF THE REDUNDANT FANS IS RATED AT 30,000 CUBIC
l
FEET PER MINUTE, AND WILL CLEARLY PROVIDE MORE THAN THE MINIMUM
[
VENTILATION REQUIREMENTS NEEDED TO LIMIT HYDROGEN CONCENTRATION TO
f
BELOW FOUR VOLUME PERCENT IN THESE COMPARTMENTS.
f
f
THE REACTOR HEAD AREA IS NOT IN THE DIRECT FLOW PATH FOR THE AIR
RETURN FAN, BUT DOES CONTAIN SEVERAL FEATURES THAT CONTRIBUTE TO
,
LlMlTING HYDROGEN ACCUMULATION.
THE COMPARTMENT CONTA1NS MORE THAN
{
250 SQUARE FEET OF OPENINGS COMMUNICATING WITH OPEN AREAS OF THE
(
LOWER CONTAINMENT.
OPENINGS EXIST BOTH IN UPPER AND LOWER REGIONS
f
t
t
l
>
'
-
-
-
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
_ - _ _ _ _ _ _ _ - - - _ _ _ _ _ _ _ - - _
.
~
.
i
-
<
.
OF THE REACTOR HEAD AREA, THEREBY ENHANCING CIRCULATION DRIVEN BY
-
,
THERMAL EFFECTS DUE TO HEATING OF THE INFLUENT AIR FROM THE LOWER
CONTAINMENT.
FOR EXAMPLE, THE THERMAL HEATING PRODUCED BY A
REACTOR HEAD TEMPERATURE OF 120 DEGREES F WOULD CREATE A
CIRCULATION OF GREATER THAN 1000 cubic FEET PER MINUTE (CFM) BASED
,
ON AN AVERAGE LOWER CONTAINMENT TEMPERATURE OF 100 DEGREES, WHILE
ASSUMING FLOW PATH LOSS COEFFICIENTS AS PRESENTED IN SECTION 6.2 OF
THE FSAR.
THESE CONSERVATIVE TEMPERATURES ARE TYPICAL OF VALUES
WHICH COULD BE EXPECTED LONG TERM IN A POST-ACCIDENT SITUATION.
THIS EXPECTED ,' LOW VALUE COMPARES VERY FAVORABLY WITH A MINIMUM
COMPARTMENT FLOW REQUIREMENT OF 172 CFM FOR LIMITING COMPARTMENT
CONCENTRATION TO BELOW FOUR VOLUME PERCENT.
THE MINIMUM COMPARTMENT FLOW REQUIREMENT IS BASED ON THE PEAK
COMPARTMENT REQUIREMENT FOR A PRIMARY COOLANT BREAK IN THAT
COMPARTMENT.
IF THE EREAK WERE TO OCCUR IN THE REACTOR
CCMPARTMENT, THE ESCAPING FLUIDS WOULD INCREASE TURBULENCE INSIDE
THE COMPARTMENT, THEREBY DECREASING THE POTENTIAL FOR HYDROGEN
ACCUMULATION.
IF A BREAK OCCURRED OUTSIDE THE REACTOR COMPARTMENT,
THE SKlMMER SYSTEM FLOW REQUIREMENT WOULD BE SIGNIFICANTLY LESS
THAN THE 172 CFM VALUE.
IN EARLY STAGES OF THE POST-ACCIDENT
SCENARIO, COMPARTMENT CIRCULATION DRIVEN BE THERMAL EFFECTS WOULD
BE AT ITS GREATEST WHEN NEEDED MOST.
AS THE PRIMARY COOLANT SYSTEM
COOLED TO NEAR AMBIENT TEMPERATURE IN THE LONG TERM AND DECREASED
THE THERMAL EFFECTS IN THE REACTOR COMPARTMENT, HYDROGEN PRODUCTION
BY RADIOLYSIS WOULD DECREASE ACCORDINGLY BASED ON THE DECREASING
RADIOLOGICAL SOURCE TERM.
CONSIDERING THESE FACTORS AFFECTING THE ACTUAL COMPARTMEt.T FLOW
REQUIREMENTS, IT IS HIGHLY UNLIKELY THAT THE CLOSED SKIMMER INLET
VALVES IN THE REACTOR HEAD AREA WOULD HAVE CAUSED THE COMPARTMENT
CONCENTRATION TO EXCEED FOUR VOLUME PERCENT.
IN ADDITION TO THE
NUMEROUS MITIGATING FACTORS, AN ADDITIONAL LEVEL OF PROTECTION IS
PROVIDED BY THE HYDROGEN MITIGATION SYSTEM, WHICH, THROUGH
OPERATION OF THE HYDROGEN IGNITERS, 15 CAPABLE OF LIMITING HYDROGEN
CONCENTRATION TO BELOW DETONABLE LEVELS, TO APPROXIMATELY SIX
VOLUME PERCENT.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ ___ ________ ___ __ ____ _____ __ _ __
_
_ _ _ _ _ _ _ _ _ _ _ _ _
.
.
.
.
INADEQUATE VX SYSTEMS FLOWS (UNIT 1)
'
AT THE BEGINNING OF THE OCTOBER, 1988 REFUELING OUTAGE FOR MCGUlRE
UNIT 1, AS-FOUND FLOW READINGS WERE RECORDED USING THE STATIONARY
HOOD DEVICE.
INITIAL READINGS IN TWO (2) COMPARTMENTS WERE FOUND
TO BE BELOW THE MINIMUM FLOW REQUIREMENTS FOR LIMITING
CONCENTRATION TO LESS THAN FOUR VOLUME PERCENT.
THE TWO (2) AREAS
FOUND DFFICIENT IN FLOW WEDE THE REACTOR HEAD AREA AND THE
PRESSURIZER COMPARTMENT.
,
AS PREVIOUSLY DISCUSSED FOR MCGUIRE UNIT 2, THE CIRCULATION
PRODUCED BY THERMAL EFFECTS IN THE REACTOR HEAD AREA, IN
l
CONJUNCTION WITH TIME-DEPENDENT REDUCTION IN RADIOLYTIC HYDROGEN
GENERATION, WOULD LIKELY HAVE PREVENTED THE COMPARTMENT HYDROGEN
CONCENTRATION FROM REACHING FOUR VOLUME PERCENT.
THE PRESSURIZER COMPARTMENT IS A DEAD-ENDED REGION THAT DOES NOT
DIRECTLY BENEFIT FROM CIRCULATirN PRODUCED BY THE C)NTAINMENT AIR
RETURN FANS.
THE CALCULATED MINIMUM SKIMMER SYSTEM FLOW RATE TO
LIMIT COMPARTMENT HYDROGEN CONCENTRATION TO BELOW FOUR VOLUME
,
PERCENT IS 121 CUBIC FEET PER MINUTE (CFM).
MEASURED FLOW RATE
W!TH FAN 1B OPERATING WAS 281 CFM, AND MEASURED FLOW WITH FAN 1A
OPERATING WAS 85 CFM.
BASED ON THE FLOW MEASUREMENT RECORDED FOR FAN 1A, THE PRESSURIZER
I
COMPARTMENT HYDROGEN CONCENTRATION COULD HAVE RLACHED 4.8 VOLUME
PERCENT.
ALTHOUGH 4.8 VOLUME PERCENT EXCEEDS THE CONSERVATION
l
DESIGN BASIS LIMIT OF 4.0 VOLUME PERCENT, IT IS VERY UNLIKELY THAT
l
HYDROGEN AT 4.8 VOLUME PERCENT WOULD IGNITE AND BURN EVEN IN DRY
AIR AND IN THE PRESENCE OF AN IGNITION SOURCE.
HOWEVER, IF BURNING
,
WERE TO OCCUR, ESSENTIAL EQUIPMENT LOCATED IN THE PRESSURIZER
COMPARTMENT HAS BEEN ANALYZED AND DETERMINED ABLE TO SURVIVE EVEN
i
THE BURNING OF HYDROGEN FROM THE 75'$ METAL WATER REACTION OF A
,
l
I
DEGRADED CORE ACCIDENT.
THE ANTICIPATED MAXIMUM CONCENTRATION OF
4.8 VOLUME PERCENT IS CLEARLY WELL BELOW DETONABLE LEVELS, AND IS
NOT CONSIDERED A DETRIMENT TO MAINTAINING CONTAINMENT INTEGRITY AND
TO CONDUCTING A STABLE POST-ACCIDENT RECOVERY.
!
1
- -
-
-
-
- -
_ - - - - - - _ _ -
- - - - - - - - - _ - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - -
-
---
,
.
<
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e
.
ANALYSIS OF SAFETY SIGNIFICANCE
METHOD
i
USE REVISED ASSUMPTIONS FOR H SOURCE
'
2
-
TERMS
,
RECOMPUTE REQUIRED FLOW RATES PER
-
,
COMPARTMENT
COMPARE TO AS-FOUND VX SYSTEM
-
CAPABILITY
!
FURTHER ASSESS ANY LOW-FLOW
l
-
COMPARTMENTS
!
,
,
Y
, - . - - - , _ - _ . _ _ - - - - _ _ -
_
_ . - _ _ . . _ - _ . - - - _ . - _ , . - - - - _ - - . , _ . _ , _
-- - _ _
.
.- _ . _ , - _ - ,_.
-
- -
-
---
--
-
- _ - . - - - - - - - - - - _ _ - _ . . _ _ . - . _ _ _ _
e
e
e
9
i
,
COMPARTMENT MODEL
t
I
r
.
X sefm
m
m
V
V
I
t
A N
A k
.
i
1
1
'
t
l
i
[
H,
H 2
,
I
i
l
,
,
l
i
l
l
l
!
!
i
-
1
l
!
!
!
I
i
l
l
!
!
.
!
i
l
I
!
]
.
.
8
l
1
l
4
I
i
- - _ _ __ - -_ _ . _ _ - _
-
- - - _ - _ - - _ - _ . - _ _ _ _-
-
- - -
- . .
-- _
-
- .
_
_ _ ,
- _
_
_
.
.
4
.
t
ORIGINAL,W ANALYSIS
,
I
$
_
X sofm
1.8%
3.5%
'
,
i
i k
J L
4
i
H,
ZlRC REACT
H, - RADIOL
,
(6.0%)
H , - Al
(CONSTANT)
,
i
,
l
1
?
l
l
l'
4
I
- _.
...
-
.
.
.
.
.
REVISED DUKE ANALYSIS
X' s of m
'
0.6%
3.9%
i l
J L
H 2 - ZlRC REACT
H 2- RADIOL
(1.5%)
H 2- Al + Zn
H - PRIM COOL
(TEMP DEP)
2
l
l
.
___ __
.
_--
.--
_
._
.
_ .
_.
._
-
.
.
.
s
.
EXAMPLE FLOW COMPARISON
COMPARTMENT:
SG-1 A
ORIGINAL WESTINGHOUSE
138 SCFM
.
REVISED DUKE
121 SCFM
AS FOUND (VX-A)
214 SCFM
,
AS FOUND (VX-B)
916 SCFM
_ _ - . , _ _ _ - . - , _ _ _ _ _ _ _ . . . _ _
_
.
. -
. . .
.
. _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ . _ . . . _ _ _
_ _ _ _ _ . _ _ _ . _ _ _ _
~
,
,
.
COMPARTMENTS WITH LOW FLOW
'
.
'
(AS-FOUND)
COMPARTMENT
ASSESSMENT
UNIT 1
REACTOR HEAD
THERMAL CONVECTION
PRESSURIZER
COULD HAVE REACHED
4.8% WELL BELOW
DETONABLE
UNIT 2
-
REACTOR HEAD
THERMAL CONVECTION
EAST FAN ROOM
AIR RETURN FAN
VENTILATION
WEST FAN ROOM
AIR RETURN FAN
..
VENTILATION
ACCUM. ROOM 20
AIR RETURN FAN
VENTILATION
ACCUM. ROOM 2D
AIR RETURN FAN
VENTILATION
-
_ - _ _ _ .
. . . - .
-
- -
.
e
e
4
4
ANALYSIS OF SAFETY SIGNIFICANCE
CONCLUSIONS
ONE COMPARTMENT ON ONE UNIT COULD
.
EXCEEDED DESIGN LIMIT.
.
NO SIGNIFICANT SAFETY IMPACT.
-
NEGLIGIBLE EFFECT ON POSTULATED
.
DEGRADED CORE ACCIDENT.
,
- - - - -
- - - -
.
-
_
e
o
.
FUNCTIONAL VERIFICATION PROGRAM
.
DEFICIENCIES
,
DEFINITIONS
POST-MAINTENANCE TESTING - THE POST-MA.NTENANCE iESTING PROGRAM
AT McGUIRE CONSISTS OF A FUNCTIONAL VERIFICATION PROGRAM AND A
RETEST PROGRAM.
FUNCTIONAL VERIFICATION - A CHECK TO ENSURE THAT THE
REQUESTED MAINTENANCE WAS PERFORMED AND THAT THE SUBJECT
EQUIPMENT PERFORMS ALL OF ITS INTENDED FUNCTIONS AND IS
FUNCTIONING PROPERLY PRIOR TO DECLARING THE EQUIPMENT
RETEST - THE FORMAL PERFORMANCE OF ALL OR PORTIONS OF
PREOPERATIONAL OR PERIODIC TESTING TO VERIFY THE COMPONENT
OR SYSTEM MEETS APPLICABLE ACCEPTANCE CRITERIA AND/OR
TECHNICAL SPECIFICATION REQUIREMENTS.
SOME MAINTENANCE MAY ONLY REQUIRE A FUNCTIONAL VERIFICATION
WHILE OTHER MAINTENANCE MAY REQUIRE BOTH FUNCTIONAL
VERIFICATION AND RETEST.
POST-MODIFICATION TESTING - THE POST-MODIFICATION TESTING IS
TESTING CONDUCTED TO CONFIRM THAT MODIFICATIONS PERFORM AS EXPECTED
AND THAT OTHER SYSTEMS OR COMPONENTS ARE NOT ADVERSELY AFFECTED.
POST MODIFICATION TESTING MAY CONSIST OF ANY COMBINATION OF
FUNCTIONAL VERIFICATION, RETEST, OR SPECIAL TESTS.
k
e
o
.
OVERVIEW / SEQUENCE OF EVENTS
.
THIS PRESENTATION INVOLVES SEVERAL EVENTS, SOME VERY COMPLEX,
DATING BACK TO FEBRUARY, 1987.
A DRIEF DESCRIPTION OF THE
EVENTS THAT LEAD INTO THE DISCOVERY OF THE NATURE OF THE
PROBLEMS WILL BE PROVIDED AND THEN A HISTORICAL REVIEW AND BRIEF
DESCRIPTION OF ALL THE EVENTS MENTIONED IN THE NRC INSPECTION
REPORT WILL BE PRESENTED.
RECENT EVENTS THAT UNCOVERED THE NATURE OF THE
FUNCTIONAL VERIFICATION PROGRAM DEFICIENCIES
INV-1428
CATAWBA NUCLEAR STATION RECENTLY FOUND SOME LINKS OPEN IN SAFETY
RELATED ELECTRICAL CIRCUITS AND PASSED ON THE CONCERNS TO
,
1
l
McGUIRE, THROUGH DUKE'S OPERATING EXPERIENCE PROGRAM.
McGUIRE
FELT WE MAY BE VULNERABLE TO THE SAME PROBLEM SO WE INSPECTED OUR
SYSTEMS AND FOUND AN OPEN LINK ON A SAFETY RELATED VALVE IN THE
CHEMICAL AND VOLUME CONTROL SYSTEM (VALVE INV-1428).
THIS LINK
,
WAS PART OF THE ELECTRICAL CIRCUITRY WHICH PROVIDED AUTOMATIC
CLOSURE OF THE VALVE.
THE LINK HAD BEEN LEFT OPEN FOLLOWING THE
IMPLEMENTATION OF A MODIFICATION DURING THE UNIT 1 1987 REFUELING
OUTAGE.
PERSONNEL ERROR WAS THE POSSIBLE ROOT CAUSE.
FUNCTIONAL
VERIFICATION OF THE MODIFICATION HAD FAILED TO ENSURE THE LINK
WAS CLOSED.
",
t
O
.
.
.
INS-18(1)
AS A RESULT OF THE INV-142 INCIDENT, PROJECTS PERSONNEL AND ISE
MET AND DECIDED TO REVIEW OTHER SiMILAR MODIFICATIONS ON UNIT 1
AND UNIT 2.
TESTS WERE DEVELOPED AND CONDUCTED TO VERIFY THAT
THE MODIFIED COMPONENTS WERE STILL FULLY OPERABLE.
THIS TESTING
REVEALED THAT 2 OTHER VALVES, INS-18 AND INS-1, IN THE
CONTAINMENT SPRAY SYSTEM, WERE INOPERABLE DUE TO INCORRECT
WlRING.
AS IN THE INV-142B INCIDENT, THESE PERSONNEL ERRORS WERE
NOT DETECTED BY THE FUNCTIONAL VERIFICATION OF THE MODIFICATION.
Dbd
IN JUNE OF 1988 DURING THE IMPLEMENTATION OF A MODIFICATION, IT
WAS DISCOVERED THAT ANOTHER WIRING ERROR HAD OCCURRED MAKING A
VALVE ON THE DECAY HEAT REMOVAL SYSTEM INOPERABLE (VALVE
2NU-48).
THE WIRING HAD BEEN IN THIS CONFIGURATION SINCE THE
PREVIOUS MODIFICATION ON THE VALVE THE YEAR BEFORE.
AGAIN, THIS PERSONNEL ERROR WAS NOT DETECTED BY THE FUNCTIONAL
VERIFICATION CONDUCTED AS PART OF THE POST MODIFICATION TESTING
PROGRAM.
0
s
4
-
.
HISTORICAL OVERVIEW
.
AS A RESULT OF THESE THREE EVENTS, NRC AND DUKE CONDUCTED A
REVIEW TO EVALUATE OUR HISTORY WITH FUNCTIONAL VERIFICATION.
LISTED BELOW, IN CHRONOLOGICAL ORDER, ARE THE EVENTS THAT WERE
JUDGED TO BE ASSOCIATED WITH FUNCTIONAL VERIFICATION, BY DUKE
AND/OR THE NRC.
FEBRUARY, 1987
VALVE INM-26 - A WlRING FAULT IN A NEW
-
ACTUATOR WAS NOT IDENTIFIED BY FUNCTIONAL
VERIFICATION WHEN INSTALLED.
THIS IS AN
EXAMPLE IDENTIFIED IN THE RECENT NRC
INSPECTION REPORT.
APRIL, 1987
INPO IDENTIFIED A FINDING IN THE AREA OF
-
FUNCTIONAL VERIFICATION.
ALTHOUGH THEY DID
NOT FIND SIGNIFICANT EVIDENCE OF FAILURE TO
ADEQUATELY PERFORM FUNCTIONAL VERIFICATION,
THEY FELT OUR PROGRAM WAS TOO DEPENDENT ON
THE INDIVIDUAL JUDGMENT OF THE TECHNICIAN AND
SUPERVISION.
THEY FELT WE SHOULD STRUCTURE
THE PROGRAM AND MAKE IT MORE PRESCRIPTIVE.
DUKE AGREED TO ENHANCE THE PROGRAM BUT AT
THAT TIME DID NOT BELIEVE WE HAD INOPERABLE
EQUIPMENT IN THE FIELD.
VALVE IND-67 - THE WORK CONTROL SYSTEM HAD
AUGUST, 1987
-
INCORRECTLY IDENTIFIED THIS VALVE AS
NON-SAFETY RELATED AND ALSO DID NOT SPECIFY A
FUNCTIONAL VERiflCATION TO BE DONE FOLLOWING
ROUTINE CAllBRATION OF THE INSTRUMENT THAT
CONTROLS THE VALVE.
A PERSONNEL ERROR
OCCURRED IN THE CAllBRATION LEAVING THE VALVE
THIS IS AN EXAMPLE IDENTIFIED IN
THE RECENT NRC INSPECTION REPORT.
's
o
.
.
VALVE 1RN-2358 - REPAlR WORK WAS DONE ON THIS
NOVEMBER, 1987
-
VALVE AND SUBSEQUENTLY FUNCTIONALLY VERIFIED
AND RETESTED PROPERLY.
ADDITIONAL REPAlR
WORK WAS NEEDED SO MAINTENANCE PERSONNEL USED
THE SAME WORK REQUEST TO COMPLETE THE REPAIR
AND AGAIN FUNCTIONALLY VERIFIED THE VALVE
PROPERLY BUT IT WAS NOT RETESTED (STROKE
TIMED).
THE VALVE WAS OPERABLE WHEN LATER
RETESTED.
Tili3 VAS A PERSONNEL ERROR IN THE
WORK CONTROL PROCESS IN IMPLEMENTING POST
MAINTENANCE RETEST.
THIS IS AN EXAMPLE
IDENTIFIED IN THE NRC INSPECTION REPORT.
FEBRUARY, 1988
VALVE 1RN-21 - A MAINTENANCE WORK PLANNER
-
FAILED TO SPECIFY THE REQUIREMENT TO RETEST
THIS VALVE FOLLOWING A PACKING ADJUSTMENT.
THIS WAS A PERSONNEL ERROR IN THE WORK
. K~ROL PROCESS IN IMPLEMENTING POST
40 NTENANCE RETEST.
THIS IS AN EXAMPLE
.9 TIFIED IN THE RECENT NRC INSPECTION
nEF (f.
JUNE, 1988
VALVE 2ND-4 - PREVIOUSLY DESCRIBED.
-
AUGUST, 1988
VALVE INV-142B - PREVIOUSLY DESCRIBED.
-
SEPTEMBER, 1988 -
VALVES INS-18 S INS-1 - PREVIOUSLY DESCRIBED.
ALTHOUGH ALL THESE EVENTS WERE RELATED IN VARYING DEGREES TO THE
FUNCTIONAL VERIFICATION / RETEST PROGRAM, THE LAST 3 EVENTS WERE
THE MOST SIGNIFICANT SINCE THEY HAVE IDENTIFIED A DEFICIENCY IN
THE BASIC STRUCTURE OF THE FUNCTIONAL VERIFICATION PROCESS.
THE
REMAINDER OF THE PRESENTATION WILL FOCUS ON THcSG 3 SPECIFIC
EVENTS, THEIR ROOT CAUSES, OUR CORRECTIVE ACTIONS AND THE SAFETY
IMPACT.
o
'
.
6
.
FUNCTIONAL VERIFICATION PROGRAM
.
SEQUENCE OF EVENTS
,
DATE
TIME
EVENT
AN INPO AUDIT IDENTIFIED DEFICIENCY (MA.3-1)
4/87
IN THE FUNCTIONAL VERIFICATION PROGRAM.
THE
DEFICIENCY STATED THAT THE GUIDELINES FOR
FUNCTIONAL VERIFICATION TESTS 00 NOT SPECIFY
ALL APPROPRIATE TESTS THAT SHOULD BE
CONSIDERED FOLLOWING MAINTENANCE.
5/87-5/88 ----
A NEW MECHANICAL MAINTENANCE PROCEDURE MMP
1.6 WAS BEING DEVELOPED TO PROVIDE MORE
SPECIFIC GUIDELINES ON FUNCTIONAL VERIFICATION
TESTING.
'
A MODIFICATION WAS PERFORMED TO MOVE THE
6/87
TORQUE SWITCH BYPASS TO AN ADD-ON PACK, AND TO
REPLACE ALL JUMPERS WITH QUALIFIED WIRE.
WIRE
NO. 16 WAS NOT PART OF THE JUMPER WIRE CHANGE,
BUT WAS DISCONNECTED AND SUBSEQUENTLY
RECONNECTED TO THE WRONG TERMINAL AFTER THE
JUMPER WIRES WERE REPLACED WITH QUALIFIED
WIRE.
WIRE NO. 16 WAS INDEPENDENTLY VERIFIED
AS BEING ON THE PROPER TERMINAL.
IT WAS LATER
DISCOVERED NOT TO BE THE CASE.
-
~ -
.
.-
- . .
. - .
-- -
-._-
_ _ - . _ . _ _-
-
. - - -
. - -
.
.,
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,
,
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,-' - .
9/87-10/87 ----
IAE PERSONNEL PERFORMED THE TORQUE SWITCH
BYPASS MODIFICATION ON VALVE ACTUATORS
__
1NI-184B(185A).
THE MODIFICATION INCLUDED
MOVING THE PERMISSIVE INTERLOCK WIRING FOR
VALVES-1NS-1B(18A) TO A PREVIOUSLY UNUSED SET
OF LIMIT SWITCHES TO MAKE ROOM FOR THE BYPASS
,,
/-
WIRING.
CMD PERSONNEL WERE PERFORMING A MODIFICATION
6/15/88
ON 2NI-184 AND FOUND WlRE NO. 16 TO BE
INCORRECTLY CONNECTED TO TERMINAL 42.
t
.
CMD PERSONNEL COMPLETED THE MODIFICATION AND
PLACED WIRE NO. 16 ON TERMINAL 31 AS PART OF
!
THE MORE RECENT MODIFICATION.
QA PERSON DISCOVERED THE MISPLACED WIRE
6/27/88
,
DURING AN AUDIT OF THE MODIFICATION.
QA PERSON RESEARCHED THE ELECTRICAL CIRCUlTRY
FOR THE WIRE AND DETERMINED IT WAS PART OF THE
AUTOMATIC CLOSURE CIRCUlTRY FOR VALVE 2ND-4.
lAE PERSONNEL WERE PERFORMING AN INSPECTION
8/29/88
OF ATC4A AND DISCOVERED LINK l-1 OPEN.
,
l
IAE PERSONNEL RESEARCHED THE ELECTRICAL
CIRCUlTRY FOR LINK l-1 AND FOUND THAT THE LINK
WAS PART OF THE AUTOMATIC CLOSURE CIRCUITRY
'
FOR VALVE INV-142B.
8/29/88
lAE PERSONNEL NOTIFIED OPS CONTROL ROOM
PERSONNEL OF THE OPEN'D LINK IN THE AUTOMATIC
CLOSURE CIRCUlTRY FOR VALVE INV-1428.
.
> 1
.y
.
.
.
IAE PERSONNEL CLOSED LINK l-1 AND FUNCTIONALLY
8/29/88
.
VERIFIED THAT THE AUTOMATIC CLOSURE CIRCUlT
WAS NOT OPEN FOR V'ALVE INV-1428.
~8/30/88- ----
PROJECT SERVICES PERSONNEL REVIEWED ALL
9/1/88
PREVIOUS TORQUE SWITCH BYPASS MODIFICATIONS
FOR DOCUMENTATION OF AN ADEQUATE FUNCTIONAL
VERIFICATION.
9/2/88
PROJECT SERVICES PERSONNEL INITIATED A WORK
REQUEST TO REVERIFY THE INTERLOCKS BETWEEN
VALVES 1NI-184B (185A) AND INS-1B(18A).
9/2/88
IAE PERSONNEL DISCOVERED ELECTRICAL
PERMISSIVE INTERLOCK CONTACT IAS3 BETWEEN
VALVES INI-184B(185A) AND INS-1B(18A) OPEN
WHEN IT SHOULD HAVE BEEN CLOSED AND CONTACTED
OPS PERSONNEL CONCERNING THE DISCREPANCY.
9/3/88
PROJECT SERVICES PERSONNEL INITIATED A
MODIFICATION TO JUMPER THE OPEN CONTACT 1AS3
AND IAE PERSONNEL INSTALLED A JUMPER AROUND
PERMISSIVE INTERLOCK CONTACT lAS3 AND THIS
RETURNED ELECTRICAL CONTROL OF VALVES INS-1B
(18A) TO OPS CONTROL ROOM PERSONNEL.
l
9/9/88
STATION PERSONNEL REVIEWED AN EARLIER
INCIDENT IN WHICH A WIRING ERROR ON 2NI-184B
DISABLED THE REQUIRED SWITCHOVER FUNCTION.
10/1/88
FUNCTIONAL VERIFICATION PROCEDURE MMP 1.3 IS
PHASED OUT AND REPLACED BY MMP 1.6.
,
. , ,
.-
.
.
.
PROBLEM DISCOVERED - 8/29/88
OPEN ELECTRICAL LINK FOUND WHICH DEFEATED AUTOMATIC CLOSURE OF
VALVE 1NV-142.
ROOT CAUSE
DURING MODIFICATION ON VALVE IN 1987 REFUELING OUTAGE TO C)lANGE
OPERATOR MODEL AND ADD ELECTRICAL ANTI-HAMMER CIRCUIT, A WIRING
CHANGE CONNECTED A PREVIOUSLY UNUSED ELECTRICAL LINK.
PERSONNEL ERROR RESULTED IN LINK REMAINING OPEN.
o
,
.
j
.
(
.
'
.,
,
,.,
SAFETY ANALYSIS
A)
THE SAFETY SYSTEM SIGNAL FOR THE AUTOMATIC CLOSURE OF VALVE
1NV-142B HAD BEEN DEFEATED, HOWEVER:
VALVE INV-142B COULD HAVE BEEN CLOSED LOCALLY AS WELL AS
FROM THE CONTROL ROOM.
VALVE INV-141A WAS OPERABLE DURING THIS TIME PERIOD AND
CAPABLE OF ISOLATING THE VCT.
B)
IN THE EVENT OF A SMALL BREAK LOCA DURING THIS TIME PERIOD AND
INV-141A WAS INCAPABLE OF BEING CLOSED:
THE VCT WOULD BE DEPLETED AND ITS HYDROGEN BLANKET COULD
ENTER THE NV PUMP SUCTION LINE, RENDERING THE PUMPS
INOPERABLE IN APPROXIMATELY 18 1/4 MINUTES AFTER SAFETY
ACTUATION.
VALVE INV-142 COULD HAVE BEEN CLOSED LOCALLY IN 15
MINUTES.
THE REACTOR COULD BE SHUTDOWN SAFETY WITH THE CONTROL
RODS.
MAKEUP TO NC SYSTEM WOULL BE PROVIDED BY SI PUMPS
WHEN PRESSURE REACHED 1500 PSIG.
.
.
NY SYSTD(
,
'
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NORMAL LETDOWN AND CHARCINC
(!( .
.
.
9,
.
4;
. .,
LETDOWN FROM NC SYSTDI
V
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CONTROL
TAMK
NV-141
-
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NV-221
MAKEUP TO
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i
NV-222
v
NV PUMP
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.
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.
,
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CORRECTIVE ACTION
1)
IAE PERSONNEL CLOSED LINK L-1 AND FUNCTIONALLY
VERIFIED AUTOMATIC OPERATION OF VALVE INV-142.
2)
ALL MODIFICATION PACKAGES ON VALVE OPERATORS FOR BOTH
UNITS WERE REVIEWED FOR ADEQUATE FUNCITONAL
VERIFICATION.
TEMPORARY TEST PEOCEDURES WERE
INITIATED WHERE APPROPPIATE.
3)
MAINTENANCE MANAGEMENT PROCEDURE 1.6 ISSUED WHICH
DEFINES THE MINIMUM FUNCTIONAL VERIFICATION
REQUIREMENTS.
REVISION IN PROGRESS AT TIME OF EVENT
DISCOVERY.
4)
CHANGES TO PROCEDURES ON REMOVAL AND INSTALLATION OF
VALVE OPERATORS WHICH INCLUDE FUNCTIONAL VERIFICATION
REQUIREMENTS FOR ALL LIMIT SWITCHES, ASSOCIATED
,
INTERLOCKS AND AUTOMATIC FUNCTIONS.
!
.
. - - -
, < . .
. .
, . ,
.
.
.
.
INS-1, 18
PROBLEM DISCOVERED
9/2/88
.
ELECTRICAL CONTACT FOUND OPEN WHICH BLOCKED OPEN PERMISSIVE
t
NECESSARY TO OPEN INS-1,18 WHEN 1NI-184, 185 REACHED FULL OPEN
POSITION.
ROOT CAUSE
POSSIBLE PERSONNEL ERROR IN TORQUE SWITCH BYPASS MODIFICATION
ON 1NI-184, 185 DURING 1987 REFUELING OUTAGE.
,
.
.
.
.
.
SAFETY ANALYSIS,
THE FUNCTION OF NS-1,18 IS TO ISOLATE THE A(B) NS PUMP FROM REACTOR
BUILDING SUMP LINE A(B).
DURING THE INJECTION PHASE OF A LOCA
NS-1,18 IS CLOSED AND THE NS PUMP IS TAKING A SUCTION FROM THE FWST
VIA NS-20(3).
ON A LOW-LOW FWST LEVEL NS PUMP A(B) IS STOPPED AND
ITS SUCTION IS REALIGNED BY THE CONTROL ROOM OPERATOR FROM THE FWST
TO THE CONTAINMENT SUMP BY CLOSING NS-20(3) AND OPENING NS-18(1)
SINCE NI-185(184) HAS ALREADY OPENED AUTOMATICALLY.
NS PUMP A(B) IS
THEN RESTARTED.
THEREFORE, IN ORDER FOR NS-18(1) TO OPEN,
NI-185(184) MUST BE OPEN AND NS-20(3) CLOSED.
DURING THE ABOVE TIME PERIOD, NS-18(1) COULD NOT HAVE BEEN OPENED
FROM THE CONTROL ROOM IF THE NS-20(3) AND NI-185(184) PERMISSIVES
HAD BEEN MET DUE TO THE 1AS-3 CONTACT SETUP ERROR IN THE SWITCH PACK
ON N1-185(184).
NS-18(1) COULD HAVE BEEN MANUALLY OPENED LOCALLY
IF N1-185(184) WERE TO OPEN.
THE NORMAL ALIGNMENT OF NS IS WITH
NS-20(3) OPEN AND NS-18(1) AND N1-185(184) CLOSED.
THE US SWAP OVER TO THE CONTAINMENT SUMP FROM THE FWST IS PERFORMED
BY CONTROL ROOM OPERATORS USING EMERGENCY PROCEDURE EP/1/A/5000/2.3.
THUS, DURING THE ABOVE TIME PERIOD WHEN THE SUBJECT INTERLOCK WAS
NOT FUNCTIONAL THE NS-18(1) VALVE REALIGNMENT COULD HAVE BEEN
PERFORMED MANUALLY IF REQUIRED.
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.
CORRECTIVE ACTION
INS-1,18
1)
OPS SHIFT PERSONNEL WERE INFCRMED THAT INS-1B AND 18A
WOULD HAVE TO BE MANUALLY OPERATED LOCALLY DURING ACCIDENT
CONDITION.
2)
IAE PERSONNEL IMPLEMENTED MEVN-1454 WHICH RETURNED CONTROL
TO CONTROL ROOM SWITCH BY PLACING JUMPER AROUND OPEN
CONTACT.
3)
MODIFICATION INITIATED TO REMOVE JUMPER AND CORRECT OPEN
CONTACT AT VALVE OPERATOR.
TO BE COMPLETED DURING 1988
REFUELING OUTAGE.
4)
CHANGES TO PROCEDURES ON REMOVAL AND INSTALLATION OF VALVE
OPERATORS WHICH INCLUDES FUNCTIONAL VERIFICATION
REQUIREMENTS FOR ALL LIMIT SWITCHES, ASSOCIATED
INTERLOCKS, AND AUTOMATIC FUNCTIONS.
,
5)
IAE PERSONNEL HAVE REVIEWED ALL WORK REQUESTS WHICH
INVOLVE SAFETY RELATED MOTOR OPERATED VALVE ACTUATOR WORK
SINCE THE LAST ESF TEST ON BOTH UNITS.
6)
IAE PERSONNEL WILL HEAD A REVIEW GROUP TO STUDY THE
STATION'S FUNCTIONAL VERIFICATION, RETEST AND
POST-MODIFICATION TESTING PROGRAMS TO ENSURE PROPER
OVERLAP EXISTS.
,
i
-_
--
-
.
-.
.
.
.
PROBLEM DISCOVERED - 6/27/88
WIRE WAS CONNECTED TO WRONG TERMINAL ON 2NI-184 OPERATOR WHICH
CAUSED THE INTERLOCK THAT AUTO CLOSES 2ND-4 TO BE INOPERABLE.
ROOT CAUSE
PERSONNEL ERROR WAS MADE DURING MODIFICATION ON TORQUE SWITCH
BYPASS IN 1987 REFUELING OUTAGE.
.
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_ _ - _ -
. - -
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O
.
.
.
SAFETY ANALYSIS
THE RESIDUAL HEAT REMOVAL (ND) AUTOMATIC SWITCH OVER SEQUENCE
FROM THE INJECTION MODE TO THE COLD LEG RECIRCULATION MODE
CAUSES THE CONTAINMENT SUMP ISOLATION VALVE 2NI-184B TO OPEN.
THIS AUTOMATICALLY INITIATES THE CLOSURE OF 2ND-4B.
THIS
OPERATION ISOLATES THE WST ND PUMP SUCTION AND ALIGNS IT TO
THE CONTAINMENT SUMP.
THE MIS-WIRED INTERLOCK WOULD HAVE
PREVENTED THE CLOSURE OF 2ND-4B.
ON VERIFICATION OF SWITCH OVER, THE OPERATOR WOULD NOTE THAT
2ND-4B WAS STILL OPEN AND CLOSE IT.
THE OPERATOR STILL
RETAINED FULL REMOTE CONTROL OF THE VALVE.
ALSO, PER
PROCEDURE, THE UPSTREAM FWST ISOLATION VALVE 2FW-27A, WOULD BE
CLOSP.D BY TTfE OPERATOR AFTER SWITCH OVER.
THI.a ISOLATES FWST.
THE MIS-WIRED INTERLOCK HAD NO ADVERSE EFFECT ON THE SAFETY
INJECTION RECIRUT ATION VALVE ALIGNMENTS AND OPERATOR ACTION TO
CLOSE 2ND-4B IS AVAILABLE.
THEREFORE, THE SAFETY INJECTION
FUNCTION REMAINED OPERABLE.
I.
q
.
.
.
CORRECTIVE ACTION
1)
ALL NSM PACKAGES WERE REVIEWED FOR ADEQUATE FUNCTIONAL
VERIFICATION.
TEMPORARY TEST WERE WRITTEN TO PERFORM
FUNCTIONAL VERIFICATION WHERE APPROPRIATE.
2)
MAINTENANCE MANAGEMENT PROCEDURE
1. 6 ISSUED WHICH DEFINES
THE MINIMUM FUNCTIONAL VERIFICATION RZQUIREMENTS FOR A
PARTICUU R COMPONENT.
REVISION IN PROORESS AT TIME OF
EVENT DISCOVERY.
3)
CHANGES TO PROCEDURES ON REMOVAL AND INSTALLATION OF VALVE
OPERATORS WHICH INCLUDE FUNCTIONAL VERIFICATION
REQUIREMENTS FOR ALL LIMIT SWITCHES, ASSOCIATED
i
'
INTERLOCKS, AND AUTOMATIC FUNCTIONS.
l
l
4)
REVIEW )F ALL WORK REQUEST ON SAFETY RELATED MOV'S
ACTUATORS.
l
5)
REVIEW GROUP TO STUDY FUNCTIONAL VERIFICATION, RETEST AND
POST-MODIFICATION TESTING PROGRAMS.
.
.
o
.
,
GENERIC CORRECTIVE ACTIONS
-
1)
FUNCTIONAL VERIFICATION RE JIREMENTS, MMP-1.6, FULLY
IMPLEMENTED WITH ALL TRAINING COMPLETED.
2)
CHANGES MADE TO THE FOLLOWING PROCEDURES TO GIVE MORE
DETAILED GUIDANCE FOR WORK ON VALVE OPERATORS.
IP/0/A/3066/01A - REMOVAL & INSTALLATION OF LIMITORQUE
,
vPERATORS
-
IP/0/A/3066/02A - REMOVAL & INSTALLAT*0N OF ROTORK
OPERATORS
3)
RELATED INSTANCES WILL BE REVIEWED WITH ALL IAE PERSONNEL
REVIEW IN PROGRESS.
4)
HAVE REVIEWED ALL WORK ON UNIT 2 SAFETY RELATED MOV'S
ACTUATORS SINCE LAST SAFEGUARDS FUNCTIONAL TEST AND
ADEQUACY OF FUNCTIONAL VERIFICATION EXNIINED.
SIX UNIT 2
VALVES HAVE BEEN IDENTIFIED FOR FUFTHER EVALUATION.
TESTING WILL BE COMPLETED ON UNIT 1 DURING CURRENT
REFUELING OUTAGE.
5)
SPECIAL REVIEW GROUP REVIEWING FUNCTIONAL VERIFICATION,
RETEST, AND POST-MODIFICATION TESTING TO ENSURE ALL AREAS
ARE COVERED.
r
6)
ENGINEERED SAFETY FEATURES ACTUATION TEST WILL BE
CONDUCTED AT END OF FUTURE REFUELING OUTAGES TO ENSURE
E
I
SYSTEMS FUNCTION AS DESIGNED.
,
,
l
i
1
- - -
- -
.
- -
.
-
-
.
.
. - .
.
.
.
.
-
-
.
-
.
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Wiring Functional Verification Checklist
'
l Terminals l Device l Function i
l0l IlCl
I
Device
i Method Used for functional
I
i
I
l
Verification
l
l
26 - 27
l
CT/LS ICLars T$ l #P6NGD du 7dAfut au clos ( 5tATI
I V Vl
'
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l
24 - 25
l
OT/LS 10F(>/ L S 10MNED #M t./MIT TET/f f SPf4 FEAT l V l V I Y l
t
l
6-
7
l
CAS1
lbfbl6Y
l#aNV tYttfD #Ns' 'dY r
-[u$ [
I V I V I V l
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15 - 16
i
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INdT Uf6D l
A//A
l
l
8-
9
i
CAS2
lit C t.lG#T lC.pNTAsL Rsorvi VsRiric.Afte r/
lVI K V[
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17 - 13
l
OAS2
lGRGtd UGHTICinT(ot. wm VGtiflCAYION
l V l Vi vl
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4
FURTHER REVLEW OF POST OCCURRENCES BY NRC AND STATION PERSONNEL
HAVE IDENTIFIED ADDITIONAL POTENTIAL INDICATORS OF INCOMPLETE
FUNCTIONAL VERIFICATION FOLLOWING MAINTENANCE.
EXAMPLE 1:
"lN FEBRUARY 1987, POST MAINTENANCE TESTING ON INM26B
WAS INADEQUATE IN THAT WHATEVER TESTING WAS PERFORMED Dl0 NOT
REVEAL THAT TERMINALS HAD SHORTED, CAUSING THE VALVE TO CYCLE OPEN
ON AN ESF SIGNAL INSTEAD OF CLOSE".
A FAILED ACTUATOR MOTOR WAS REPLACED AND THE VALVE WAS
IT ' LECTRICALLY FROM THE CONTROL
FUNCTIONALLY TESTED BY CYCLING
c
ROOM.
THE VALVE'S INDICATIONS WAS VERIFIED TO WORK CORRECTLY AND
,
THE LEAK TEST AND VALVE STROKE TIMING TEST WERE COMPLETED
]
SATISFACTORlLY.
LATER, THE VALVE CYCLED CONTINUOUSLY DURING A
SLAVE RELAY TEST AND A WIRE TERMINAL WAS FOUND SHORTED AGAINST THE
$
BARREL NUT.
SINCE INM-26B HAD BEEN SUCCESSFULLY CYCLED FROM 1HE
CONTROL BOARD, ITS FUNCTION WAS DEMONSTRATED.
EXAMPLE 2:
"lN AUGUST, 1987, NO RETEST WAS PERFORMED ON THE FLOW
INSTRUMENT CONTROLLING ND PUMP 1B RECIRCULATION VALVE, IND67B,
,
RESULTING IN A VIOLATION".
,
WORK WAS PERFORMED ON THE FLOW INSTRUMENT CONTROLLING ND PUMP 1B
RECIRCULATION VALVE IND678, USING A PROCEDURE THAT DID NOT
i
IDENTIFY THE COMPONENT AS BEING SAFETY RELATED AND DID NOT REQUIRE
FUNCTIONAL VERIFICATION SUBSEQUENT TO MAINTENANCE.
HOWEVER, THE
ROOT CAUSE OF THE INCIDENT WAS DUE TO A FAILURE TO FOLLOW
l
PROCEDURE WHICH LEFT THE INSTRUMENT ISOLATED AND PROPER FUNCTIONAL
!
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VERIFICATION WAS NOT PERFORMED.
I
EXAMPLE 3:
"ON NOVEMBER 19, 1987, WHILE REVIEWING AN lAE WORK
REQUEST FOR FINAL SIGNOFF, AN lAE STAFF PERSON DISCOVERED THAT
f
f
ADDIT ONAL TESTING WAS NEEDED ON 1RN235B, 1B NS HEAT EXCHANGER
'
COOLING WATER INLET".
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,
. .
.
- - - - - - - - - - - - - - - - - - - - - . _ _ _ _ _ _ - - - -
--
o
.
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A SEAT LEAK ON VALVE 1RN-235B WAS REPAIRED UNDER A WORK REQUEST.
-
A RETEST AND FUNCTIONAL VERIFICATION WERE SUCCESSFULLY COMPLETED
ON THE VALVE.
WHEN A LEAK DEVELOPED, THE NEXT DAY THE ORIGINAL
WORK REQUEST WAS REOPENED TO PERFORM THE WORK.
NO RETEST WAS
PERFORMED ON THIS VALVE.
THE ROOT CAUSE FOR THIS INCIDENT WAS
PERSONNEL ERROR.
A CONTRIBUTING CAUSE WAS DUE TO A PROCEDURAL
DEFICIENCIES (MMP 1.0 AND 1.3) WHICH ALLOWED A WORK REQUEST TO BE
REOPENED ONCE IT HAS BEEN SIGNED COMPLETE.
SUBSEQUENT CHANGES TO
THE WORK CONTROL SYSTEM HAS ELIMINATED THE USE OF A WORK REQUEST
FOR ADDITIONAL WORK AFTER RETEST IS COMPLETED.
AFTER FURTHER REVIEW, THE FOLLOWING ONE EXAMPLE, CITED IN NRC
INSPECTION REPORT 369/88-29, INDICATE A PROBLEM WITH THE WORK
CONTROL SYSTEM.
THIS PROBLEM HAS BEEN ADDRESSED SEPARATELY TO
RCDUCE THE POSSIBILITY OF RECURRdNCE.
EXAMPLE 4:
"ON MARCH 28, 1988, IT WAS DETERMINED 1RN21 UNDERWENT
i
MAINTENANCE WITHOUT A SUBSEQU21T RETEST".
A PACKING ADJUSTMENT WAS PERFORMED ON 1RN21 UNDER A WORK REQUEST.
THE WORK REQUEST INCORRECTLY IDENTIFIED THAT A RETEST WAS NOT
l
REQUIRED AND RN21 IS IDENTIFIED AS A COMPONENT REQUIRING RETEST
l
PER STATION DIRECTIVES.
HOWEVER, THE ERROR THAT OCCURRED WAS THE
RESULT OF PERSONNEL ERROR AND A FAILURE TO FOLLOW PROCEDURES AND
l
WAS NOT DUE TO THE FAILURE OF THE FUNCTIONAL VERIFICATION PROGRAM.
.
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