ML18011B021

LER 95-006-00:on 950824,determined Discrepancy Re Design of RAB EES Constituted Condition Outside Design Basis.Cause Still Under Investigation.Established Administrative Leakage Limit of 1 Gallon Per hour.W/950922 Ltr

ML18011B021
Person / Time
Site:	Harris
Issue date:	09/22/1995
From:	Donahue J, Verrilli M CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HO-950702, LER-95-006-01, LER-95-6-1, NUDOCS 9509280061
Download: ML18011B021 (5)

Text

PRIORITY (ACCELERATED RIDS PROCESSING)

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9509280061 DOC.DATE: 95/09/22 NOTARIZED: NO DOCKET FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 P AUTH. NAME AUTHOR AFFILIATION VERRILLI,M. Carolina Power & Light Co.

DONAHUE,J.W. Carolina Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATXON

SUBJECT:

LER 95-006-00:on 950824,determined discrepancy re design of RAB EES constituted condition outside design basis. Cause still under investigation. Established administrative leakage limit of 1 gallon per hour.W/950922 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED LTR ENCL SIZE TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:Application for permit renewal filed. 05000400 T

RECIPIENT COPIES RECIPXENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 PD 1 1 LE,N 1 1 INTERNAL: ACRS AEOD/SPD/RRAB 1 1 AEO ~~RAB 2 2 1 1 ENT 1 1 NRR/DE/ECGB 1 1 N~'D E B 1 1 NRR/DE/EMEB 1 1 NRR/DISP/PIPB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 D NRR/DRCH/HOLB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SPSB/B 1 1 NRR/DSSA/SRXB 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 2 2 C '

NOAC MURPHY,G.A 1 1 NOAC POORE,W. 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 M '

N

'O TO ALL "RIDS" RECZPZENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESKS ROOM OWFN 5DS (415 2083) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUXRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 27 ENCL 27

Carolina Power 8 Light Company Harris Nuclear Plant PO Box 165 New Hill NC 27562 SEP 22 1995 Letter Number: HO-950702 U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 95-006-00 Gentlemen:

In accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report concerns an identified condition that was determined to be outside the design basis of the plant, related to the Reactor Auxiliary Building Emergency Exhaust System.

Sincerely, J. W. D nahue General Manager Harris Plant MV Enclosure Mr. S. D. Ebneter (NRC - RII)

Mr. N. B. Le (NRC - PM/NRR)

Mr. S. A. Elrod (NRC - SHNPP) 9S0928006i 950922 PDR ADOCK OS000400 S PDR State Road 1134 New Hill NC

NRC- FORN (5-92) 366 LICENSEE EVENT REPORT t U.S. NUCLEAR REGULATORY COHHISSION (LER)

APPROVED BY OHB NO.

EXPIRES 3150-0104 4/30/98 ESTINTED BURDEN PER RESPONSE TO CQNPLY WITH THIS INFORNTION COLLECTION REQUEST: 50.0 HRS.

REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSING PROCESS AND FEO BACK TO INDUSTRY.

(See reverse for required number of digits/characters for each block) FORWARD CQNNENTS REGARDING BURDEN ESTINTE TO THE INFORNTION AND RECORDS NNAGEHENT BRANCH U.S. NUCLEAR REGULATORY CDYiNISSION. WASHINGTON.

DC 20555-0001. ANO TO THE PAPERWORK REDUCTION PROJECT (3150-0104). OFFICE OF NNAGENENT AND BUDGET. WASHIHGTON. OC 20503.

FACILITY NAHE (1) DOCKET NUMBER (2) PAGE (3)

Shearon Harris Nuclear Plant-Unit //1 1 of 3 TITLE (4) Emergency Core Cooling System piping not fully contained within Reactor Auxiliary Building Emergency Exhaust S stem bounda resultin in condition outside desi n basis.

EVENT DATE (5) LER HUNBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

SEQUENTIAL REVISION FACILITY NANE DOCKET NUNBER HONTH DAY YEAR YEAR NUNBER NUYBER NONTH DAY 05000 08 24 95 95 -- 006 00 09 22 95 FACILITY HANE DXKET NUHBER 05000 OPERATING THIS REPORT IS SUBHITTED PURSUANT TO THE REQUIREHENTS OF 10 CFR 5: (Check one or mor e) (ll)

HODE (9) 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)(1)(i) 50.36(c)(l) 50.73(a)(2)(v) 73.71(c) 76K LEVEL (10) 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) (Specify in 20.405(a)(1)(iv) X 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) Abstract below and in Text, 20.405(a)(l)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x) NRC Form 366A)

LICENSEE CONTACT FOR THIS LER (12)

NANE TELEPHONE NUNBER (Include Area Code)

Michael Verrilli Sr. Analyst - Licensing (919) 362-2303 COHPLETE ONE LINE FOR EACH COHPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COHPONENT NNUFACTURER REPORTABLE TO NPRDS

",,,:i'.ii<j;:"',:;:ll::;: CAUSE SYSTEH CONPONENT NNUFACTURER TO NPROS SUPPLEHENTAL REPORT EXPECTED (14) HONTH DAY YEAR EXPECTED YES SUBMISSION X ( If yes. complete EXPECTED SUBNISSION DATE). DATE (15) 11 30 95 ABSTRACT (Limit to 1400 spaces. i.e.. approximately 15 single-spaced typewritten lines) (16)

On August 24, 1995, a discrepancy related to the original design of the Reactor Auxiliary Building (RAB) Emergency Exhaust System was determined to constitute a condition outside the design basis of the plant as described in the Harris Plant Final Safety Analysis Report (FSAR). This discrepancy pertains to a portion of Emergency Core Cooling System (ECCS) piping that is physically located outside of the boundary of the RAB Emergency Exhaust System envelope, which adversely impacts the dose assessments that were performed in the FSAR. In the event leakage consisting of highly radioactive water occurred from this section of piping during a postulated design basis loss of coolant accident (LOCA), the discrepancy would introduce non-conservative factors into the FSAR analysis performed to determine dose rates resulting from ECCS leakage outside Containment. Specifically, the FSAR dose rate analysis assumed that released effluent would first be processed through the RAB Emergency Exhaust System filtration units, prior to being released to the atmosphere. This was based on the fact that all leakage was assumed to be contained within the RAB Emergency Exhaust System envelope and did not factor in the potential increased dose resulting from "unfiltered" leakage from the RAB which could occur outside the system boundary.

The cause of this condition is still under investigation and will be provided in a supplement to this LER.

Compensatory measures have been established to allow for continued operation. These measures include development of administrative ECCS leakage limits, monitoring and inspection of the subject ECCS piping and administrative controls to maintain the RAB boundary to minimize unfiltered leakage from being released to the atmosphere in the event of the postulated accident scenario. A 1-hour non-emergency report was made to the NRC per 10CFR50.72, via the Emergency Notification System.

NRC FORM (5-92) 366A LICENSEE EVENT REPORT (LER) t APPROVED BY OMB NO.

ESTIMATED BURDEN EXPIRES PER 3150-0104 5/31/95

RESPONSE

THIS INFORMATION COLLECTION REQUEST:

TO COMPLY WITH 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714). U.S. NUCLEAR REGULATORY CONISSION.

WASHINGTON. OC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104) . OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

SEQUENTIAL REVISION YEAR NUMBER Shearon Harris Nuclear Plant - Unit ¹I 05000/400 NUMBER 2 OF 3 95 006 00 TEXT (If more space 'is required. use additional copies of NRC Form 3664) (17)

EVENT DESCRIPTION:

In July 1995, during a review of regulatory issues, the validity of the dose assessment analysis for Emergency Core Cooling System (ECCS) leakage outside of containment, contained in section 15.6.5 of the Harris Final Safety Analysis Report (FSAR), was questioned by Harris plant personnel. Additional research into this analysis was performed by CP8cL Engineering personnel. The main concern was that the methodology of the ECCS leakage assumptions in the dose calculation did not match the assumptions in the Standard Review Plan (SRP). After reviewing sufficient information confirming that a potential problem did indeed exist, a Condition Report (CR ¹95-1862) was initiated on August 7, 1995, and a formal investigation was initiated to resolve the concern. After re-evaluating the ECCS components located outside the boundary of the RAB Emergency Exhaust System and the corresponding assumed external leakage rates, it became apparent that dose rates exceeded those values originally used to establish the licensing basis of the plant.

A 1-hour non-emergency report for a condition outside the design basis of the plant was made to the NRC per 10CFR50.72, via the Emergency Notification System on August 24, 1995.

Continued operation was justified with compensatory measures that included establishment of an ECCS leakage limit of 1 gallon per hour to ensure that off site dose remains within 10CFR100 limits. In addition, the affected piping areas are being monitored for leakage and radiation monitor trends are being periodically reviewed by operators as an early means of leakage detection. Further engineering analysis efforts continue and the results of these will be provided with a supplement to this Licensee Event Report.

CAUSE / SAFETY SIGNIFICANCE:

The cause of this condition and the associated safety significance are still under investigation. Information will be provided in a supplement to this LER upon completion of a formal root cause investigation and additional engineering analysis to evaluate the resulting dose from ECCS leakage.

PREVIOUS SIMILAR LERs:

There have been no similar LER's submitted.

CORRECTIVE ACTIONS COMPLETED:

The following compensatory measures have been established and are applicable for operation in Modes 1-4 pending completion of the engineering analysis:

1. An administrative leakage limit of 1 gallon per hour has been established for this portion of the ECCS system. This administrative limit provides assurance that offsite doses would remain within 10CFR100 limits.

2. The affected piping areas are being periodically inspected for leakage by Operations personnel.

3. Radiation monitor trends are being periodically reviewed by Operations personnel as an early means of leakage detection.

4. Administrative controls were developed to maintain the RAB boundary to minimize unfiltered leakage.

NRC FORM (5-92) 366A LICENSEE EVENT REPORT U.S. NUCLEAR REGULATORY COMMISSION (LER) t APPROVED BY OMB NO.

EXPIRES 3150-0104 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714). U.S. NUCLEAR REGULATORY COMMISSION.

WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104) . OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DXKET NUMBER (2) LER NUMBER (6) PAGE (3)

SEQUENTIAL REVISION YEAR Shearon Harris Nuclear Plant - Unit ¹I 05000/400 NUMBER N(1vBER 3 OF 3 95 006 00 TEXT (If more space is required, use additional copies of /(RC Form 3664) (17)

CORRECTIVE ACTIONS PLANNED:

1. A root cause investigation will be completed.

2. Additional engineering analysis will be performed to determine the impact this design has on applicable dose rate calculations.

Revisions will be made to the Harris FSAR as appropriate and will be submitted to the NRC.

4. A supplement to this LER will be developed and submitted to the NRC.

EIIS INFORMATION:

S stem Name/Code:

Chemical and Volume Control System (CVCS) - CB Residual Heat Removal/Low Pressure Safety Injection - BP High Pressure Safety Injection - BQ