IR 05000269/1990017
| ML15261A298 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/18/1990 |
| From: | Reyes L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Tucker H DUKE POWER CO. |
| References | |
| NUDOCS 9007270059 | |
| Download: ML15261A298 (15) | |
Text
JUL 1 8 W U Docket Nos. 50-269, 50-270, 50-287 License Nos. DPR-38, DPR-47, DPR-55 Duke Power Company ATTN:
Mr. H. B. Tucker, Vice President Nuclear Production Department P. 0. Box 1007 Charlotte, NC 28201-1007 Gentlemen:
SUBJECT: ENFORCEMENT CONFERENCE SUMMARY (INSPECTION REPORT NOS. 50-269/90-17, 50-270/90-17 AND 50-287/90-17)
This letter refers to the Enforcement Conference held at our request on July 12, 199 This meeting concerned activities authorized for your Oconee facilit The issue discussed at this conference related to a design deficiency in the Penetration Room Ventilation System. A list of attendees, a summary, and a copy of your handout are enclosed. We are continuing our review of these issues to determine the appropriate enforcement actio In accordance with Section 2.790 of the NRC's "Rules of Practice," Part 2, Title 10, Code of Federal Regulations, a copy of this letter and its enclosures will be placed in the NRC Public Document Roo Should you have any questions concerning this letter, please contact u
Sincerely, Luis A. Reyes, Director Division of Reactor Projects Enclosures:
1. List of Attendees 2. Enforcement Conference Summary 3. Enforcement Conference Handout cc w/encl s:.
H. B. Barron Station Manager Oconee Nuclear Station P. 0. Box 1439 Seneca, SC 29679 (cc w/encls cont'd -
see page 2)
F, DOCK 0500026 PDC-
Duke Power Company
cc w/encls:
(Continued)
County Supervisor of Oconee County Walhalla, SC 29621 Robert B. Borsum Babcock and Wilcox Company Nuclear Power Generation Division Suite 525, 1700 Rockville Pike Rockville, MD 20852 J. Michael McGarry, III, Es Bishop, Cook, Purcell *and Reynolds 1400 L Street, NW Washington, D. C. 20005 Office of Intergovernmental Relations 116 West Jones Street Raleigh, NC 27603 Heyward G. Shealy, Chief Bureau of Radiological Health South Carolina Department of Health and Environmental Control 2600 Bull Street Columbia, SC 29201 Manager, LIS NUS Corporation 2536 Countryside Boulevard Clearwater, FL 33515 Paul Guill Duke Power Company P. 0. Box 1007 Charlotte, NC 28201-1007 Karen E. Long Assistant Attorney General N. C. Department of Justice P. 0. Box-629 Raleigh, NC 27602 State of South Carolina bcc w/encls:
(See page 3)
Duke Power Company
JUL 1 8 'Mu bcc w/encls:
L. Wiens, NRR B. R. Bonser, RII M. B. Shymlock, RH A. R. Herdt, RII Document Control Desk NRC Resident Inspector U.S. Nuclear Regulatory Commission Route 2, Box 610 Seneca, SC 29678 J. Lieberman, OE RII RI GKelly AH dt J
7//7/90 7/\\/90
ENCLOSURE 1 LIST OF ATTENDEES U.S. Nuclear Regulatory Commission S. D. Ebneter, Regional Administrator, Region II L. A. Reyes, Director, Division of Reactor Projects (DRP)
E. W. Merschoff, Acting Director, Division of Reactor Safety (DRS)
D. B. Matthews, Director, Project Directorate 11-3, NRR G. R. Jenkins, Director, Enforcement and Investigation Coordination Staff (EICS)
A. R. Herdt, Branch Chief, DRP L. D. Wert, Resident Inspector, Oconee K. N. Jabbour, Project Manager, NRR B. Uryc, Senior Enforcement Coordinator, EICS P. J. Kellogg, Section Chief, DRS W. T. Orders, Senior Resident Inspector, Catawba R. D. Gibbs, Reactor Engineer, DRS B. R. Bonser, Project Engineer, DRP Duke Power Company M. S. Tuckman, General Manager Nuclear Support H. B. Barron, Station Manager, Oconee B. L. Peele, Design Engineering, Oconee Engineering Division T. Curtisz, Oconee Compliance Manager P. Guill, Regulatory Compliance R. Lytton, Design Engineering, Oconee Engineering Division C. Hanlin, Oconee Operations B. Dolan, Oconee Design Engineering
ENCLOSURE 2 ENFORCEMENT CONFERENCE SUMMARY On July 12, 1990, representatives from Duke Power Company (DPC)
met with the NRC in the Region II office in Atlanta, Georgia to discuss a design deficiency in Oconee's Penetration Room Ventilation Syste Following opening remarks by Stewart Ebneter, NRC RII, Regional Administrator, DPC gave a presentation on the issue (Enclosure 3).
DPC's presentation covered a description and design basis of the Penetration Room Ventilation System; a design history; a description of the problem and current condition of the system; the Generic Letter 88-14 response, corrective actions and results; and a safety assessment. In summary, DPC made five major points:
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The root cause was an initial design deficiency in that all loss of instrument air events were not adequately addresse The response to Generic Letter 88-14 was not broad enough in scop Passive valves need to be tested in addition to the active valves already teste The problem would probably have been identified during the Design Basis Documentation effor However, DPC acknowledged that this system was of a lower priority and would not have been looked at soo Off-site doses would not be significant with respect to Part 100 limits using realistic assumption The system was fully functional at all time The NRC closed the meeting by stating that Duke's presentation had served to enhance Region II's understanding of this issue and their corrective action ENCLOSURE 3 OCONEE NUCLEAR STATION PENETRATION ROOM VENTILATION SYSTEM DESIGN DEFICIENCY NRC ENFORCEMENT CONFERENCE JULY 12, 1990
INTRODUCTION SYSTEM DESCRIPTION AND DESIGN BASIS DESIGN HISTORY DESCRIPTION OF THE PROBLEM AND CURRENT CONDITION GENERIC LETTER 88-14 RESPONSE CORRECTIVE ACTIONS AND RESULTS SAFETY ASSESSMENT SUMMARY
Pii SII II I
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.J
DESIGN BASIS PROCESS CONTAINMENT LEAKAGE FOLLOWING A MAXIMUM HYPOTHETICAL ACCIDENT (MHA)
ASSUMPTIONS 50% OF LEAKAGE IS PROCESSED BY PRVS FILTERS 90% REMOVAL RATE OF IODINES
DESIGN HISTORY INITIAL DESIGN:
MANUAL HANDWHEEL THROTTLE VALVES DESIGN CHANGE TO REMOTE OPERATED AOV'S, IN RESPONSE TO NRC CONCERNS FOR OPERATOR RADIATION EXPOSURE (MARCH 1970)
FAIL CLOSED DESIGN APPARENTLY CHOSEN TO PROTECT FILTER FROM HIGH FLOW DURING LOSS OF INSTRUMENT AIR EVENT FOLLOWING LOSS OF OFFSITE POWER EVENT, SYSTEM RECOVERY POSSIBLE IF FAILED CLOSED, BUT POSSIBLY NOT IF FILTER DAMAGED FROM EXCESSIVE FLOW FAIL CLOSED DESIGN WELL DOCUMENTED THROUGHOUT PLANT HISTORY
DESCRIPTION OF THE PROBLEM AND CURRENT CONDITION CONCERN WITH FAIL CLOSED DESIGN RAISED BY NRC RESIDENT INSPECTOR (JUNE 1990)
NEITHER FAIL CLOSED NOR FAIL OPEN DESIGN IS FULLY ACCEPTABLE PRESENT DESIGN IS FAIL TO THROTTLED POSITION WITH (NON-SEISMIC) REMOTE CAPABILITY FOR OPENING EXPERIENCE AND ANALYSIS DO NOT SHOW NEED TO RE-THROTTLE
GENERIC LETTER 88-14 RESPONSE UTILIZED OCONEE "ACTIVE" VALVE LIST AS BASIS FOR REVIEW OF INSTRUMENT AIR PROBLEMS PASSIVE VALVES NOT INCLUDED IN SCOPE OF REVIEW PR-13 AND 17 NOT CLASSIFIED AS ACTIVE GL 88-14 REQUESTED DESIGN VERIFICATION OF ALL COMPONENTS WITH SAFETY FUNCTION
CORRECTIVE ACTIONS AND RESULTS VALVES MODIFIED AND OPERABILITY EVALUATION PROVIDED ALL AIR OPERATED VALVES REVIEWED
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-1075 ADDITIONAL VALVES EVALUATED
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66 VALVES CLASSIFIED AS PASSIVE
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3 VALVES ADDED TO ACTIVE LIST
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NO ADDITIONAL PROBLEMS IDENTIFIED LONG TERM DESIGN OF PR-13 AND 17 UNDER EVALUATION OCONEE FSAR AND GL 88-14 RESPONSE REVISIONS TO BE SUBMITTED MCGUIRE AND CATAWBA GL 88-14 RESPONSES BEING REVIEWED
SAFETY ASSESSMENT EXCLUSION AREA BOUNDARY 2-HOUR THYROID DOSES WITHOUT PENETRATION ROOM VENTILATION SYSTEM RELEASE (R)
ANALYSIS SOURCE TERM ASSUMPTIONS DOSE MHA LICENSING LICENSING
> 300 (50% CORE IODINES)
DBA 100% GAP LICENSING
< 20 LOCA ACTIVITY (<2% IODINES)
MHA REALISTIC REALISTIC
<1 REALISTIC DOSE ESTIMATES ARE SIGNIFICANTLY LOWER THAN PART 10CFR100 LIMITS
SUMMARY ROOT CAUSE: INITIAL DESIGN DEFICIENCY ALL LOSS OF INSTRUMENT AIR EVENTS NOT ADEQUATELY ADDRESSED GENERIC LETTER 88-14 RESPONSE DEFICIENT ONLY ACTIVE VALVES ADDRESSED PROBLEM WOULD HAVE BEEN IDENTIFIED DURING DESIGN BASIS DOCUMENTATION EFFORI REALISTIC OFF-SITE DOSES WOULD NOT BE SIGNIFICANT WITH RESPECT TO PART 100 LIMITS SYSTEM WAS FULLY FUNCTIONAL AT ALL TIMES INSTRUMENT AIR WAS OPERABLE TO PR-13 AND PR-17