ML18012A287

LER 96-009-00:on 960530,identified Deficiencies in Reactor Auxiliary Bldg Exhaust Sys.Caused by Inadequate Surveillance Test Procedures.Revised Test procedure.W/960701 Ltr

ML18012A287
Person / Time
Site:	Harris
Issue date:	07/01/1996
From:	Brooke Clark, Verrilli M CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HNP-96-107, LER-96-009, LER-96-9, NUDOCS 9607080207
Download: ML18012A287 (10)

Text

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.'ACCESSION NBR:9607080207 DOC.DATE: 96/07/01 NOTARIZED: NO, FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit '1, "Carolina DOCKET ¹ 05000400 AUTH. NAME 'AUTHOR AFFILIATION VERRILLI,M. Carolina Power & Light Co.

CLARK,B.H. Carolina Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 96-009-00:on 960530,identified deficiencies in Reactor Auxiliary Bldg Exhaust Sys.Caused by inadequate surveillance test procedures. Revised test procedure.W/960701 ltr. A DISTRIBUTION CODE'E22T COPIES RECEIVED'LTR 50.73/50.9 Licensee Event Report,(LER), Incident Rpt, etc. L ENCL / SIZE'ITLE:

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Carolina Power R Light Cotnpany Harris Nuclear Plant PO Box 165 JUL 0 1 1996 New Hill NC 27562 U.S. Nuclear Regulatory Commission Serial: HNP-96-107 ATTN: NRC Document Control Desk 10CFR50.73 Washington, DC 20555 SHEARON HARMS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 96-009-00

Dear Sir or Madam:

In accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report concerns a testing deficiency for the Reactor Auxiliary Building Emergency Exhaust System.

Sincerely, B. H. Clark General Manager Harris Plant MV Enclosure c: Mr. J. B. Brady (NRC - HNP)

Mr. S. D. Ebneter (NRC - RII)

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

'-DR 9607080207 rst6070i PDRs ADQCK 05000400 8

P'tate Road 1138 New Hill NC

U. S. Nuclear Regulatory Commission Document Control Desk / HNP-96-107 Page 2 of 2 CC: Ms. P. B. Brannan Mr. W. R. Campbell (BNP)

Mr. J. M. Collins Mr. J. P. Cowan Mr. G. W. Davis Ms. S. F. Flynn Mr. G. D. Hicks (BNP)

Mr. M. D. Hill Mr. W. J. Hindman Ms. C. W. Hobbs (HEEC)

Mr. R. M. Krich (RNP)

Ms. W. C. Langston Mr. C. W. Martin (BNP)

Mr. R. D. Martin Mr. J. W. McKay Mr. P. M. Odom (RNP)

Mr. W. R. Robinson Mr. G. A. Rolfson Mr. R. F. Saunders Mr. R. S. Stancil Mr. G. M. Stokes Mr. C. N. Sweely Mr. J. P. Thompson (BNP)

Mr. T. D. Walt Mr. R. L. Warden (RNP)

HNP Real Time Training INPO NLS File: HI/A-2D Nuclear Records

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 F).95) EXPIRES 04/30/96 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY IHFORMAT!ON COLLECTION REQUEST: 500 HRS. REPORTED LESSONS LEARNED ARE LICENSEE EVENT REPORT (LER) INCORPORATED INTO THE LICENSING PROCESS ANO FEO BACK TO INDUSTRY.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH IT6 F33L US. NUCLEAR REGULATORY COMMISSID)L (See reverse for required number of WASHINGTON, OC 205550001. AND TO THE PAPERY/ORK REDUCTION PROJECT l3150 digits/characters for each block) 0104L OFFICE OF MANAGEMENT AND BUDGET, WASHINGTOH, OC 20503.

FACILITY NAME Il) DOCKET NUMBER (2) PAGE I3)

Harris Nuclear Plant Unit-1 50-400 1 OF 3 TITLE I4)

Reactor Auxiliary Building Emergency Exhaust System testing deficiency.

EVENT DATE (5) LER NUMBER'(6) REPORT DATE (7) OTHER FACILITIES INVOLVED (6)

FACIUTY NAME DOCKETNUMBER SEQUENTIAL REVISION MONTH OAY YEAR MONTH OAY YEAR NUMBER NUMBER 05000 FACILITYNAME DOCKETNUMBER 30 96 96 009 00 7 1 96 05000 OPERATING REPORT IS SUBMITTED PUR SUANT TO THE REQUIREMENTS OF 10 CFR O: (Check one o r more) (11)

MODE (9) 20.2201(b) 20.2203(a) (2)(v) 50.73(a)(2)(i) 50.73(a) (2)(viii) 100or'HIS20.2203(a) (1) 20.2203(a) (3) (i) 50.73(a)(2)(ii) 50.73(a)(2) (x)

POWER LEVEL (10) 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50.73(a) (2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a) (4) 50.73(a) (2)(iv) OTHER 20.2203(a) (2) (iii) 50.36(c) (1) 50.73(a) (2) (v) Specrfy in Abstract below or in NRC Form 366A 20.2203(a) (2) (Iv) 50.36(c) (2) 50.73(a) (2) (vii)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER Unc)ude Ares Code)

Michael Verrilll Sr. Analyst - Licensing (919) 362-2303 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

REPORTABLE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER TO NPROS TQ NPAOS SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR YES SUBMISSION (If yes, complete EXPECTED SUBMISSION DATE). X NO DATE (15)

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On May 30, 1996 with the plant operating in Mode-1 at 100% power, deficiencies were identified in the Reactor Auxiliaty Building (RAB) Emergency Exhaust System surveillance test. Technical Specification l 4.7.7.d.3 requires the system to maintain the areas served at a negative pressure of greater than or equal to 1/8 inch water gauge relative to the outside atmosphere. This differential pressure is measured by sensing taps in three locations within the RAB. However, due to the location of these sensing taps, the pressure of each area served by the exhaust system has not been verified during past surveillance testing. Specifically, there are no pressure sensing taps located in the Charging/Safety Injection Pump rooms and since they are enclosed spaces and not connected to adjacent areas via ductwork, past testing has not verified the pressure inside these rooms. To resolve this concern the plant entered Technical Specification 4.0.3 at 12:37 hours. Revisions were made to existing test procedures to verify that the local pressure in the CSIP rooms met the negative 1/8 inch water gauge requirement. These test results were satisfactory and at 1215 on April 31, 1996, Technical Specification 4.0.3 was exited.

During the above testing on May 30 and 31, 1996, an additional concern was identified with the RAB Emergency Exhaust System surveillance testing process. The Waste Processing Building (WPB) and Fuel Handling Building (FHB) normal ventilation exhaust fans, which serve areas adjacent to the RAB, had normally been running during past RAB ventilation testing. Testing showed that these exhaust fans aided in achieving the required 1/8 inch negative pressure and since they might not be available following a loss of off-site power accident, they should have been secured. To correct this, the test procedure was revised to secure non-safety ventilation fans serving areas adjacent to the RAB. Both of these conditions were caused by improper surveillance test procedure development due to an incorrect interpretation of Technical Specification testing requirements.

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KRC FURL% 366A. US. NUCLEAR REGULATORZ COMMISSION H.96)

I.ICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITT NAME )1) OOCKET LER NUMBER IB) PAGE I3)

SEQUENTIAL REVISION TEAR NUMBER NUMBER Shearon Harris Nuclear Plant ~

Unit ft1 50400 2 OF 3 96 - 009 00 TEXT irr moro spar rs rsrropod. oso odcfzioosl sopps of INC Form 3SSLI II))

EVENT DESCRIPTION:

On May 30, 1996 with the plant operating in Mode-1 at 100% power, a deficiency was identified in the 18-month Reactor Auxiliary Building (RAB) Emergency Exhaust System (EIIS Code: VF) Operations Surveillance Test Procedure (OST-1052). This deficiency was identified as a result of the investigation performed for Licensee Event Report 196-007, submitted on May 28, 1996, which reported the failure to properly test the Control Room Ventilation System.

Technical Specification 4.7.7.d.3 requires the RAB Emergency Exhaust System to be capable of maintaining the areas served, "at a negative pressure of greater than or equal to 1/8 inch water gauge relative to the outside atmosphere." This differential pressure is measured by an instrumentation configuration (PDI-4823) that uses sensing taps in three locations within the RAB. However, due to the location of these sensing taps, the pressure of each area served by the exhaust system has not been verified during past surveillance testing. Specifically, there are no pressure sensing taps located in the Charging/Safety Injection Pump rooms and since they are enclosed spaces and are not connected to adjacent areas via ductwork, past testing has not included verification of the pressure inside these rooms.

To resolve this concern the plant entered Technical Specification 4.0.3 at 1237 hours0.0143 days <br />0.344 hours <br />0.00205 weeks <br />4.706785e-4 months <br /> on May 30, 1996. Revisions were made to the existing test procedure (OST-1052) to verify that the local pressure in the CSIP rooms met the negative 1/8 inch water gauge requirement. Calibrated manometers were used to measure the pressure inside each CSIP room and at 1215 on May 31, 1996, satisfactory results were achieved using the E6-A Exhaust Fan (EIIS Code VF-FAN) and Technical Specification 4.0.3 was exited. During this testing however, differential pressure readings in other areas of the RAB did not achieve the negative 1/8 inch pressure requirement, so the E-6A Exhaust Fan was declared inoperable placing the unit in a 7-day LCO.

An additional concern was identified with the RAB Emergency Exhaust System surveillance testing process during the May 30 - 31 performance of OST-1052. This concern involved the Waste Processing Building (WPB, EIIS Code: VH-FAN) and Fuel Handling Building (FHB, EIIS Code: VG-FAN) normal ventilation exhaust fans, which serve areas adjacent to the RAB. These fans were normally running during past RAB ventilation operability testing which unintentionally aided the development of negative 1/8 inch pressure. Since the FHB and WPB fans are not safety related, and may not be available following a loss of off-site power accident, they should have been secured during past RAB ventilation system testing. Test procedure OST-1052 was revised to include securing the non-safety WPB and FHB ventilation fans. At approximately 1230, initial testing using the E-6B Exhaust Fan (with the non-safety WPB and FHB fans secured) was unsuccessful in obtaining the required differential pressure. Investigation determined that the main control room differential pressure gage was not functioning properly. This was confirmed at approximately 1745, when satisfactory differential pressure results were obtained using local pressure gage readings within the RAB. Based on these results, the E-6B RAB Emergency Exhaust Fan was considered operable. Until the main control room differential pressure indication is functioning properly, local pressure readings will continue to be used for testing.

To resolve the problem with the E-6A Exhaust Fan, additional investigati n was,performedr, These efforts determined that the fan's gravity actuated/weighted discharge damper (EIIS Code VF-DMP) and vortex flow control inlet damper were not functioning properly. With the adjacent non-safety fans secured and the malfunctioning dampers, the E-6A fan was capable of reaching negative 0.094 inches. This problem was masked in previous RAB testing because the non-safety WPB and FHB exhaust fans aided the E-6A Fan in achieving the required negative pressure. Investigation was unable to determine the exact length of time that the A-train was in this deficient condition. Following repairs and adjustments on the E-6A Fan discharge damper and flow control loop, testing was performed that verified the Technical Specification differential pressure requirements. The fan was declared operable and returned to service at 0130 on June 6, 1996.

CAUSE:

Both of the testing deficiencies, (1) not verifying pressure inside the CSIP rooms and (2) performing RAB testing without securing the adjacent non-safety fans, were caused by inadequate surveillance test procedures, due to an incorrect interpretation of Technical Specification testing requirements during initial procedure development. The failure of the E-6A Exhaust Fan to achieve the required flow and differential pressure was caused by improper setup and adjustment of the gravity discharge damper and vortex flow control inlet damper.

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NRC EIIRLY 3BBA~ US. NUCLEAR REGULATORT COMMISSION (4 BB)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 0) DOCKET LER NUMBER (B) PAGE(3)

SEOUENTIAL REVISION NUMBER NUMBER Shearon Harris Nuclear Plant - Unit //1 50400 3 OF 3 96 - 009 - 00 TEXT fffo<oN opoooir nquao<f, iso o<f<fRihool cop)oo of NRC &m 3<ia<U (11)

SAFETY SIGNIFICANCE:

There were no adverse safety consequences associated with the RAB Emergency Exhaust System surveillance testing deficiencies. Testing completed on May 31, 1996 validated that pressures inside the CSIP rooms met the negative 1/8 inch Technical Specification requirement.

The safety significance of the E-6A Fan's inability to attain the required differential pressure due to the malfunctioning dampers and performing the test with adjacent non-safety ventilation systems secured is determined by evaluating the system's ability to contain and filter radioactive contaminants potentially generated in an accident. Testing initially performed in the "as-found" condition indicated that a negative pressure of approximately 0.094 inches could be achieved.

Calculations performed using methodology from the Industrial Ventilation Handbook and Industrial Hygienist Handbook, determined that with a negative pressure of approximately 0.094 inches, an air flow velocity of 736 fpm would be created through crack openings in the RAB boundary. With this velocity radioactive contaminants are expected to have remained within the RAB and have been exhausted through the proper filtration units. Following repairs and adjustments to the E-6A Fan's dampers, the Technical Specification negative 1/8 inch pressure requirement was achieved.

PREVIOUS SIMILAR EVENTS:

These conditions were identified as a result of the investigation performed for the Control Room Ventilation testing deficiency reported in LER f96-007. During the process of HNP's on-going NRC Generic Letter 96-01 "Technical Specification Testing Program Review," a heightened level of awareness has resulted in the identification of testing deficiencies that were caused by incorrectly interpreting Technical SpeciTication testing requirements during initial test procedure development. LER f96-002 was submitted on February 16, 1996 and has been revised several times to report the results of the on-going review process.

CORRECTIVE ACTIONS COMPLETED:

1. Testing was successfully performed on May 31, 1996 to verify that the pressure inside the CSIP rooms met Technical Specification requirements.

2. Operations Surveillance Test Procedure (OST-1052) was revised on June 24, 1996 to ensure that future testing included verification of CSIP room pressure and that adjacent non-safety ventilation systems are secured.

3. Repairs and adjustments were completed on the RAB Emergency Exhaust E-6A Fan Damper and the fan was returned to service on June 6, 1996. Similar repairs and adjustments were also made to improve the performance of the E-6B Exhaust Fan.

4. A review was performed during the investigation of this event to ensure that similar, testing deficiencies did not exist in other Technical Specification ventilation systems.

CORRE<CTIVE ACTIONS PLANNED:

1. RAB differential pressure indication in the main control room will be evaluated and improved as needed. The evaluation will be completed by December 31, 1996.

EIIS Codes:

Reactor Auxiliary Building Emergency Exhaust System - VF

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