ML18031B285
| ML18031B285 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/31/1987 |
| From: | Robert Lewis TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8704130420 | |
| Download: ML18031B285 (3) | |
Text
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,f ACCESSION NBR FAC IL: 50-259 5O-260 50-296 AUTH. NAME LEWIS. R. L.
RECIP. NANE REGULATORY ORNATION DISTRIBUTION SY N (R IDS) 8704130420 DOC. DATE: 87/03/31 NOTARIZED:
NO DOCKET ¹ Browns Ferry Nuclear Pouer Station>
Unit 1>
Tennessee 05000259 Browns Ferry Nuclear Power Station>
Unit 2>
Tennessee 05000260 Browns Ferry Nuclear Pouer Station>
Unit 3.
Tennessee 05000296 AUTHOR AFFI LIAT ION Tennessee Valley Authority RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Special rept: on 870321> loss of seismic monitoring instrumentation discovered.
Caused bg inadequacy in instructions h training. All instruments removed from site will be repaired 8c restored to operation.
DISTRIBUTION CODE:
IE22D COPIES RECEIVED: LTR ENCL SIZE:
TITLE: 50. 73 Licensee Event Report (LER)> Incident Rpt>
etc.
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05000259 05000260 05000296 RECIPIENT ID CODE/NANE JANERSON> C QEARS> Q INTERNAL: ACRS MICHELSON ACRS WYLIE AEOD/DSP/ROAB NRR/ADT NRR/DEST/ADS NRR/DEST/ELB NRR/DEST/MEB NRR/DEST/PSB NRR/DEBT/SGB NRR/DLPG/GAB NRR/DREP/EPB (NRRdj-'NASLILR8
'RE~LE'2 RGN2 FILE 01 EXTERNAL EQhQ QROH> N LPDR NSIC HARRIS J NOTES:
COPIES LTTR ENCL 1
1 1
1 1
1 1
2 2
1 1
0 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
5 5
1 1
1 12 12 RECIPIENT ID CODE/MANE BWR PD2 PD ST*NG> J ACRS NOELLER AEOD/DOA AEOD/DSP/TAPB NRR/DEST/ADE NRR/DEST/CEB NRR/DEST/ ICSB NRR/DEST/NTB NRR/DEBT/RSB NRR/DLPG/HFB NRR/DOEA/EAB NRR/DREP/R*B NRR/PMAS/PTSB RES SPEIS> T H ST LOBBY WARD NRC PDR NSIC NAYS> G COP IES LTTR ENCL 1
1 1
1 1
1 1
1 1
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1 1
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11 TOTAL NUMBER OF COPIES REQUIRED:
LTTR 54 ENCL 52
TENNESSEE VALLEY AUTHORITY Browns Ferry Nuclear Plant P.O.
Box 2000
- Decatur, Alabama 35602 March 31, 1987 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555
Dear Sir:
TENNESSEE VALLEY AUTHORITY -
BROWNS FERRY NUCLEAR PLANT (BFN) UNITS 1, 2, AND 3-DOCKET NOS.
50-259,
- 260, AND 296 - FACILITY OPERATING LICENSES DPR-33, -52, AND -68 The enclosed special report provides details concerning the loss of seismic monitoring instrumentation.
This report is being furnished pursuant to plant technical specification requirement 3.2.J.3.
Very truly yours, TENNESSEE VALLEY AUTHORITY obert L.
ewis Plant Manager Browns Ferry Nuclear Plant Enclosures cc (Enclosures):
Regional Administration
'U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region II 101 Marietta Street, Suite 2900 Atlanta, Georgia 30303 INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 NRC Resident Inspector, Browns Ferry Nuclear Plant B704130420 B70331 PDR ADOCK 05000259 8
PDR An Equal Opportunity Employer
Special Report Loss of Seismic Monitoring Instrumentation The seismic monitoring system is physically located in unit 1 at Browns Ferry Nuclear Plant (BFN) and provides seismicity data for all three BFN Units which are presently defueled.
In the course of TVA's procedures upgrade program it was recognized that vendor manuals and documentation for the seismic monitoring instrumentation, required by technical
'pecifications, needed improvement or, in some cases, the information was nonexistent.
The seismic monitoring system utilized is provided by two vendors.
Kinemetrics Systems is the supplier of three biaxial seismic:
switches (triggers),
which provide control room annunciation, and of three triaxial time history strong motion accelographs (SMA-2), located on various
. reactor building floor elevations.
Teledyne supplies three triaxial peak accelographs which are installed on piping systems within the unit 1 reactor building.
A representative from Kinemetrics Systems company was brought onsite to provide hands-on training for instrument mechanics and engineers
'relative to proper testing, calibration, and servicing of the instruments.
On March 21, 1987, culminating the four-day training course, the seismic triggers located in the reactor building on the base slab were carefully examined.
In the opinion of the vendor specialist, none of the three triggers would have provided the required control room annunciation upon receipt of a horizontal O.l g seismic acceleration.
It is not known how long the seismic triggers were not fully functional.
Located adjacent to the triggers is a SMA-2.
Immediate attention was focused on the SMA-2 located on the reactor building base slab, as it is the most critical for seismic monitoring.
After field work it was restored to operable status the next day.
Another SMA-2, located on the reactor building third floor, was not considered serviceable
- onsite, so it was taken back to Kinemetrics, along with the three seismic triggers.
The remaining SMA-2 of the three was found to be in satisfactory condition.
The vendor manuals and other instructions furnished with the instruments were not written for power plant maintenance personnel, but for seismologists.
The seismic triggers installed at BFN are approximately 15 years old and are regarded as one-of-a-kind.
Kinemetrics Systems has only recently made training available to utilities, as utilities represent a very small portion of their business.
Surveillance instructions, previously regarded as adequate, did not provide detail necessary for the average technician.
Maintenance personnel, for example, were not trained to recognize that a small crinkle in the foil-like flexor would hamper the overall performance of the seismic trigger.
Such a crinkle was found in one trigger.
All instruments removed from the site will be repaired and restored to operation within 30 days.
Surveillance instructions will be revised to include more detailed inspections of the instruments.
The surveillance procedure for the three Teledyne peak accelographs will be performed in May 1987.
They are considered at this time to be operable.
TVA geologists believe, based on regional records, that no seismic activity since initial startup has been of a magnitude (greater than 0.01 g) recordable on plant instrumentation.
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