ML023650335
| ML023650335 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 12/18/2002 |
| From: | Gallagher M Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML023650335 (4) | |
Text
Exelkn.
Exelon Nuclear www exeloncorp corn Nuclear 2oo Exelon Way Kennett Square, PA 19348 10 CFR 50.46 (a)(3)(i) and (ii)
December 18, 2002 U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555 Limerick Generating Station, Units 1 and 2 Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353
Subject:
10 CFR 50.46 Reporting Requirements
Reference:
Letter from S. A. Richards (NRC) to J. F. Klapproth (GE Nuclear Energy),
"Review of NEDE-23785, Vol. III, Supplement 1, Revision 1, "GESTR-LOCA and SAFER models for Evaluation of Loss-of-Coolant Accident Volume III, Supplement 1, Additional Information for Upper Bound PCT Calculation" (TAC No MB2774)", February 1, 2002.
Dear Sir/Madam:
In accordance with 10 CFR 50.46 (a)(3)(i) and (ii), the following is a revision to the licensing basis Loss-of-Coolant Accident (LOCA) peak clad temperatures (PCTs) for Limerick Generating Station (LGS), Units 1 and 2. Table 1 (attached) provides the revised licensing basis PCT values and the prior PCT error accumulation changes for LGS, Unit 1. Table 2 (attached) provides the revised licensing basis PCT values and the prior PCT accumulations for LGS, Unit
- 2.
Exelon Generation Company, LLC (Exelon) received a 10 CFR 50.46 notification letter from Global Nuclear Fuel (GNF) ("SAFER Core Spray Injection Elevation Error"), which informed us of a PCT impact due to an error in a code input affecting the elevation of the core spray spargers. The error affects the buildup and draining of the water in the upper plenum region above the core. The correction of the error results in an estimated increase in the licensing basis PCT of 150F for the GE14 fuel type. The error did not impact the pre-GE14 fuel types.
A second 10 CFR 50.46 notification letter was also received from GNF ("Impact of SAFER Bulk Water Level Error on the Peak Clad Temperature (PCT)"), which informed us of a PCT impact due to an error affecting the initial water level in the bulk water region of the vessel. The error occurred due to failure to properly account for the effect of the steam dryer pressure drop on the initial inventory of water in the vessel. The correction of the error results in an estimated decrease in the licensing basis PCT of 51F for all fuel types.
In the referenced letter, the NRC approved the elimination of the 1600OF limit on the upper bound peak clad temperature. Exelon has confirmed that the Safety Evaluation Report attached to the reference letter is applicable to Limerick Generating Station, Units 1 and 2.
10 CFR 50.46 Reporting Requirements December 18, 2002 Page 2 Therefore, future 10 CFR 50.46 reports will no longer include a discussion of the upper bound peak clad temperature.
The attached tables provide, by fuel type, the baseline PCTs, the prior PCT error accumulations, and the resultant estimated licensing basis PCTs for the limiting and non limiting fuel types. The estimated licensing basis peak clad temperature for the most limiting fuel type at LGS, Unit 1 (GEl4) increases to 16800F. The licensing basis PCT for the most limiting fuel type at LGS, Unit 2 (GE14) also increases to 1680 0F. The licensing basis PCT for both units has more than 500OF margin to the 2200°F limit specified in 10 CFR 50.46.
Therefore, no additional action is required.
If you have any questions, please do not hesitate to contact us.
Very truly yours, Michael P. Gallagher Director, Licensing and Regulatory Affairs Mid Atlantic Regional Operating Group Attachments cc:
H. J. Miller, Administrator, Region I, USNRC A. L. Burritt, USNRC Senior Resident Inspector, LGS S. Wall, Project Manager, USNRC
10 CFR 50.46 Reporting Requirements December 18, 2002 TABLE 1 CURRENT BASELINE PCT (OF) VALUES AND ERROR ACCUMULATION LIMERICK GENERATING STATION, UNIT 1 BASELINE PCT Prior PCT Error Accumulation 50.46 Notification Core Spray Sparger Elevation Error 50.46 Notification Bulk Water Level Error TOTAL NEW ESTIMATED LICENSING BASIS PCT VALUES P8x8R GE8 1625 1515 10 20 0
-5 5
0
-5 15 GE9 GE 11/13 GE14 1515 50 0
-5 45 1605 40 0
-5 35 1670 0
15
-5 10 1630 1530 1560 1640 1680
10 CFR 50.46 Reporting Requirements 10 CFR 50.46 Reporting Requirements December 18, 2002 TABLE 2 CURRENT BASELINE PCT (-F) VALUES AND ERROR ACCUMULATION LIMERICK GENERATING STATION, UNIT 2 P8x8R GE8 GE9 GE 11/13 GE14 BASELINE PCT 1625 1515 1515 1605 1670 Prior PCT Error Accumulation 10 20 50 40 0
50.46 Notification 0
0 0
0 15 Core Spray Sparger Elevation Error 50.46 Notification
-5
-5
-5
-5
-5 Bulk Water Level Error TOTAL 5
15 45 35 10 NEW ESTIMATED LICENSING 1630 1530 1560 1640 1680 BASIS PCT VALUES
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