05000325/LER-1981-036, Forwards LER 81-036/03L-0.Detailed Event Analysis Encl

Forwards LER 81-036/03L-0.Detailed Event Analysis Encl

ML20003E905
Person / Time
Site:	Brunswick
Issue date:	04/09/1981
From:	Dietz C CAROLINA POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20003E906	List: 05000325/LER-1981-036, Forwards LER 81-036/03L-0.Detailed Event Analysis Encl 05000325/LER-1981-036-03, /03L-0:on 810315,discovered Suppression pool-to- Reactor Bldg Vacuum Breaker 1-CAC-V17 Was Open W/Indicated Pressure Differential of 0 Psid.Caused by Pressure Switch Not Allowing Proper Calibr.Instrument Recalibr
References
BSEP-81-0786, BSEP-81-786, NUDOCS 8104170475
Download: ML20003E905 (2)

LER-1981-036, Forwards LER 81-036/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3251981036R00 - NRC Website

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bOh Md'J Carolina Power & Light Company D

Brunswick Steam Electric Plant

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O(J(f f,g f.gi P. O. Box 10429 P

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Southport, NC 28461

'PR } C,/g h April 9,1981 y,,

FILE: 509-13516 SERIAL: BSEP/81-0786

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'fr. James P. O'Reilly, Director N'

U. S. Nuclear Regulatory Commission Region II, Suite 3100 101 Marietta Street N.W.

Atlanta, GA 30303 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO.1 DOCKET NO. 50-325 LICENSE NO. DPR-71 LICENSEE EVENT REPORT 1-81-36 De.2r Mr. O'Reilly:

In accordance with Section 6.9.1.9c of the Technical Specifications for Brunswick Steam Electric Plant, Unit No. 1, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-0161, July 1977.

Very truly yours, i

C. R. Dietz, General Manager Brunswick Steam Electric Plant RMP/mcg Enclosure Mr. R. A. Hartfield[

cc:

Mr. V. Stello, Jr.

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8104i70475

LER l-81-36 ATTACHMENT Facility: BSEP Unit No.1 Date: 3-15-81 The differential pressure switch used to control the opening of the vacuum

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^ breakers, Barton Model No. 289A, is a "(-)S-0-(+)5" psid instrument. The instrument is connected such that a positive pressure in the torus with respect to the Reactor Building will cause the indication to move toward the -5 psid indication. A vacuum in the torus will cause the ins?.rument to read in the +5

'psid direction. The technica.1 specifications state that the setpoint for these instruments be -0.45 + 0.05 pid; therefore the calibration procedure was written to set the switch at -0.4510.05 psid as read on the actuation instrument. Due to the piping arrangement to the switch, this was incorrect. A check of both switches on Unit Nos. I and 2 determined that th2y had all been

~~ calibrated with the incorrect procedure. Following a thorough investigation to ensure accuracy, the calibration procedure was revised and all four switches were calibrated correctly and returned to service. During the investigation, it was noted that the accuracy of the meter is + 0.5*. of full scale, which equates to the accuracy required by the calibration. An Engineering Work Request has been submitted for engineering to determine whether a smaller span differential pressure switch (with an accuracy and setpoint repeatability better than 10.05 psid) could better serve this application to ensure technical specification compliance.

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The modification installing these switches and the automatic opening valves (V16 and V17) was installed by a plant =odification in 1979 and the switches were placed on an 18-month calibration cycle. Due to this occurrence and a similar occurrence reported in LER 2-81-14, the calibration frequency for these switches has been reduced to quarterly until reliability for a calibration is assured.

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longer periodicity

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