ML20207P888
| ML20207P888 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/14/1987 |
| From: | Kowalski S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Butler W Office of Nuclear Reactor Regulation |
| References | |
| CON-#187-2337, RTR-REGGD-01.033, RTR-REGGD-1.033 OL, NUDOCS 8701200373 | |
| Download: ML20207P888 (3) | |
Text
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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 12:51 e41 4502 S. J. KOWALsKl
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January 14, 1987 Mr. W. R. Butler, Director Docket No. 50-352 BWR Project Directorate #4 U.S. Nuclear Regulatory Commission Washington DC 30555
SUBJECT:
Limerick Generating Station Unit 1 Loose Parts Monitoring System (LPMS)
REFERENCE:
Letter J. S. Kemper (PECo) to W. R. Butler (NRC) dated August 4, 1986 FILE:
GOVT 1-1 (NRC)
Dear Mr. Butler:
In the referenced letter we submitted the required alarm levels for 100% power operation of the Limerick Unit 1 Loose Parts Monitoring System (LPMS).
Subsequent to the August 4th letter, we have had further discussions with the manufacturer, Babcock and Wilcox Company,
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and they have corrected information they provided on August 1, 1986.
The result is that the ratio of 3:1 set on each channel represents an alarm level of three times the background level, not 30% above the background as indicated in our letter of August 4, 1986.
5 Section C.1.b of Reg. Guide 1.133 Rev. 1, dated May 1981, i
recommends an on-line sensitivity of the automatic detection system to detect, as a minimum, a metallic loose part that weighs from.25 lb.
to 30 lb. and impacts at.5 ft-lbs.
If the recommended sensitivity cannot be achieved, then the in-plant conditions and the actual on-line sensitivity should be specified at the time the alert level in provided.
The following table lists the background levels at 100% power, N
,Jg the baseline calibrati, data for.5 ft-lbs. which are the impact responses a.
for three calibrated hammers, and the actual alarm levels:
C e
bo i
Average Sensor Response (G's P-P) for.5 ft/lb. Impact N
l llammer Size
Background
Alarm Channel
.25 LB 2 LB 30 LB 100% Power Level 3
LPH-1 11.3 10.7 7.8
.45 1.4 Og LPM-2 7.7 14.8 4.4
.43 1.3 h
C a.a.
LPM-3 82.1 45.7 51.7 2.71 8.1 LPM-4 16.9 34.1 56.5 2.57 7.7 1.PH-5 26.3 111.1 40.2 15.5 46.5 k%
LPH-6 67.6 73.9 53.8 2.15 6.5
\\
LPM-7 34.3 93.1 15.6 5.75 17.3 LPM-8 42.8 90.9 49.9 3.27 9.8
, T
(*
The baseline impact responses were obtained by Babcock and Wilcox Company prior to start-up of the unit. The baseline report was issued May 1984.
The underlined responses of LPM-5 and LPM-7 are below the alarm level; therefore, an impact greater than.5 ft.-lbs. is required for automatic detection. The following table indicates the expected minimum on-line sensitivity and the underlined energy level indicates those which exceed.5 ft-lbs.
Impact Required to Exceed the Alarm Level (Ft.-Lbs.)
Hammer Size Channel
.1
.7 LPM-7
.1
.04
((
The specific in-plant condition that reduces the sensitivity of LPM-5 and LPM-7 is the relative high background level caused by oscillation of the spring hanger at a frequency of 1380 to 1400 hertz.
The 1380-1400 hertz signal seen on LPM-5 and LPM-7 frequency spectrum at power levels of 80% and above is being further investigated to reduce the signal icvel and the background level. This will provide the recommended sensitivity for automatic detection (a notch filter of 1390 Hz is a possible solution).
The LPMS with the specified alert levels meets the requirements of Regulatory Guide 1.133. Rev. 1, dated May 1981. The detection system and the data acquisition equipment will automatically activate when the reported alarm levels are reached or exceeded and an audible alarm will be sounded to alert the Control Room operator.
Should you have any question concerning this system, please do not hesitate to call.
Very truly yours,
/
. J. Kowalski JTOB/cmv/Ill28609 Copy to:
R. E. Martin, US NRC See Attached Service List
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cc: Iroy 8.. Conner,-JE, Esq.
Benjamin Hr-Vogler~, Esq.
T Mr. Frank R. Romano Mr. Robert L. Anthony Ms. Maureen Mulligan Charles W. Elliott, Esq.
Barry M. Hartman, Esq.
Mr. Thomas Gerusky s
Director, Penna. Emergency Managemer.t Agency Angus Love, Esq.
David Wersan, Esq.
Robert J. Sugarman, Esq.
Kathryn S. Lewis, Esq.
Spence W. Perry, Esq.
Jay M. Gutierrez, Esq.
Atomic Safety 4 Licensing Appeal Board Atomic Safety 4 Licensing Board Panel Docket 6 Service Section E. M. Kelly Timothy R. S. Campbell 4
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