ML20034B905
| ML20034B905 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 04/24/1990 |
| From: | Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0991, RTR-NUREG-991, RTR-REGGD-01.133, RTR-REGGD-1.133 NUDOCS 9005010149 | |
| Download: ML20034B905 (3) | |
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j PHILADELPHIA ELECTRIC' COM PANY.
NUCLEAR GROUP HEADQUARTERS 955 65 CHESTERBROOK BLVD.
' WAYNE, PA 19087 5691 (als) **o 5"o April 24.-1990 Docket No. '50-353 l
f License No..NPF-85 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 i
SUBJECT:
Limerick Generating Station Unit 2 Loose Parts Monitoring System Submittal of Alarm Levels for Power Operation i
Dear Sir:
l Regulatory Guide (RG) 1.133, " Loose-Part Detection Program for the Primary System of Light-Water-Cooled Reactors," Revision No. 1. dated May 1981, L
describes a method acceptable to the NRC for implementing regulatory I
requirements with respect-to detecting loose parts in light-water-cooled reactors during normal operation. Section 4.4.6.1 of the Limerick Generating i
Station (LGS) Final Safety Analysis Report of the Loose Parts Monitoring System (LPMS)(at LGS indicates the. LGS LPMS isFSAR designed in conformance with RG 1.133. Rev. 1.
The NRC concluded that the LGS LPMS is acceptable in Section 4.4.6 of NUREG-0991, " Safety Evaluation' Report Related to the Operation of Limerick Generating Station. Units 1 and 2,"
Supplement No. 2, dated October 1984. RG 1.133 states that LPMS alarm levels for power operation should be submitted to the NRC within 90 days following l
completion of the startup test program. The LGS Unit 2 startup_ test program was completed on January 8, 1990. Accordingly, this letter.provides the alarm levels at 100% power operation for the LGS, Unit 2 LPMS.
Section C.I.b of.RG 1.133, Rev. 1, recommends an on-line sensitivity of the automatic detection system to detect, as a minimum, a metallic loose part that weighs.from 0.25 lbs to 30 lbs and impacts at 0.5 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 alarm level is provided.
The following table lists the background levels at 10u% power for LGS, Unit 2; the baseline calibration data for a 0.5 ft-lbs impact for three calibrated-hammers, and the actual alarm levels. The baseline impact responses were Dbb? D,0$$$gg PDC D
l
U.S. Nuclear Regulatory Commission April 24, 1990 Document Control Desk Page 2
.s obtained by Advanced Technology Engineering Systems prior to startup of the unit. The baseline report was issued to Philadelphia Electric Company (PECo) in j
March 1990.
t i
AVERAGE SENSOR' RESPONSE (Acceleration in "Gs" Peak to Peak) i FOR A 0.5 FT-LBS IMPACT I
HAMMER SIZE BACKGROUND ALARM **
CHANNEL
.25LB ILB 12LB*
100% POWER LEVEL LPM-1
.08
.06
.49
.30
.90-1 LPM-2 T.56
.07
.37
.19
.57 LPM-3
.18 T.lT
'.27
.81 2.43 LPM-4
.44
.92
.33 1,79 5.37 LPM-5 5.06
~2.80
.58
.32
.96 LPM-6 6.76 2.38
.67
.41 1.23 LPM-7 4.28 2.56
.28
.54 1.62 LPM-8 3.79 1.81
.41
.72 2.16
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A 30 LB hammer size was initially used during testing as recommended in RG 1.133 Rev.-1, for which proper LPMS response was observed, but was reduced 1
to a 12LB hammer size to provide for increased repeatability of an impact of 0.5 ft-lbs.
The alarm level is set at three times the background level at 100% power.
1 The underlined responses in the above table are below the alarm-level; therefore, an impact greater than 0.5 ft-lbs is required for automatic detection. The following table indicates the expected minimum on-line sensitivity required for automatic detection for those sensors whose impact level exceeds 0.5 ft-ibs.
IMPACT REQUIRED FOR AUTOMATIC DETECTION (IN FT-LBS).
I HAMMER SIZE CHANNEL
.25LB 1LB 12LB l
LPM-1 5.6 7.5
.9 LPM-2 4.1
.8 LPM-3 6.8
.76 4.5 LPM-4 6.1 3.0 8.3 L
LPM-5
.9 LPM-6
.9 L
LPM-7 2.9 LPM-8
.6 2.6 With the specified alarm levels, the LPMS at LGS Unit.2 complies with RG 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.
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JU.S.-Nuclear Regulatory Commission April:24,-1990-Document Control Desk Page 3' t4 Should you have any questions concerning this system,'please do not hesitate to call.
Very truly yours, G. A.-Hunger, Jr.
' Manager-Licensing Section Nuclear Services Department cc:
T. T. Martin, Administrator, Region I,.USNRC T. J. Kenny, USNRC Senior. Resident Inspector, LGS-l'
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