ML023650497

10 CFR 50.46 Reporting Requirements

ML023650497
Person / Time
Site:	Peach Bottom
Issue date:	12/18/2002
From:	Gallagher M Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML023650497 (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 Peach Bottom Atomic Power Station, Units 2 and 3 Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278

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 Ill, 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 Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. Table 1 (attached) provides the revised licensing basis PCT values and the prior PCT error accumulation changes for PBAPS, Unit 2.

Table 2 (attached) provides the revised licensing basis PCT values and the prior PCT accumulations for PBAPS, Unit 3.

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 40°F for all fuel types.

A second 10 CFR 50.46 notification letter was also received from GNF (Ulmpact 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 increase in the licensing basis PCT of 5 0F 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 Peach Bottom Atomic Power Station, Units 2

10 CFR 50.46 Reporting Requirements December 18, 2002 Page 2 and 3. Therefore, future 10 CFR 50.46 reports will no longer include a discussion of the upper bound peak clad temperature. The prior report noted that a MAPLHGR penalty had been implemented on the GEl 1 and GEl 3 fuel types, due to the upper bound PCT exceeding 1600°F. This MAPLHGR penalty has been removed consistent with the elimination of the 1600OF upper bound PCT limit.

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 PBAPS, Unit 2 (P8x8R) and Unit 3 (P8X8R) increases to 1890 0F. The licensing basis PCT for both units has more than 300OF margin to the 2200°F limit specified in 10 CFR 50.46. No additional actions are 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. C. McMurtray, USNRC Senior Resident Inspector, PBAPS J. Boska, Senior Project Manager, USNRC

10 CFR 50.46 Reporting Requirements December 18, 2002 TABLE 1 CURRENT BASELINE PCT (-F) VALUES AND ERROR ACCUMULATION PEACH BOTTOM ATOMIC POWER STATION, UNIT 2 P8x8R GES GE9 GE 11/13 GE14 BASELINE PCT 1735 1624 1624 1645 1450 Prior PCT Error Accumulation 110 135 165 145 55 50.46 Notification 40 40 40 40 40 Core Spray Sparger Elevation Error 50.46 Notification 5 5 5 5 5 Bulk Water Level Error TOTAL 155 180 210 190 100 NEW ESTIMATED LICENSING 1890 1804 1834 1835 1550 BASIS PCT VALUES

q 10 CFR 50.46 Reporting Requirements December 18, 2002 TABLE 2 CURRENT BASELINE PCT (-F) VALUES AND ERROR ACCUMULATION PEACH BOTTOM ATOMIC POWER STATION, UNIT 3 P8x8R GE8 GE9 GE 11/13 GE14 BASELINE PCT 1735 1624 1624 1645 1450 Prior PCT Error Accumulation 110 135 165 145 55 50.46 Notification 40 40 40 40 40 Core Spray Sparger Elevation Error 50.46 Notification 5 5 5 5 5 Bulk Water Level Error TOTAL 155 180 210 190 100 NEW ESTIMATED LICENSING 1890 1804 1834 1835 1550 BASIS PCT VALUES