NL-11-1652, CFR 50.46 ECCS Evaluation Model Significant Change/Error Report

CFR 50.46 ECCS Evaluation Model Significant Change/Error Report

ML112270307
Person / Time
Site:	Hatch
Issue date:	08/12/2011
From:	Ajluni M Southern Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
NL-11-1652
Download: ML112270307 (6)

Text

Mark J. Ajluni, P.E. Southern Nuclear Nuclear Licensing Director Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295 Birmingham, Alabama 35201 Tei 205.992.7673 Fax 205.992.7885 August 12, 2011 SOUTHERN'\'

COMPANY Docket Nos.: 50-321 NL-11-1652 50-366

u. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant 10 CFR 50,46 ECCS Evaluation Model Significant Change/Error Report Ladies and Gentlemen:

In accordance with the requirements of 10 CFR 50,46(a)(3)(ii), Southern Nuclear Operating Company (SNC) is submitting the enclosed Edwin I. Hatch Nuclear Plant (HNP) emergency core cooling system (ECCS) evaluation model significant change/error report.

On July 21, 2011, SNC received notification of two change/error reports which included the respective estimated effects on the HNP limiting ECCS analysis fuel peak cladding temperature (PCT). The estimated effects of these two change/error reports have been added to the estimated effects of the changes/errors previously reported in the annual report. The resultant accumulation of the absolute magnitudes of the applicable change/error estimated effects is greater than 50 of. This accumulation constitutes a significant change/error requiring a 30 day report. The resulting HNP PCT continues to meet the criterion of 10 CFR 50.46(b)(1) (Le., S 2200 OF) with sufficient margin such that no reanalysis is required.

This letter contains no NRC commitments. If you have any questions, please contact Jack Stringfellow at (205) 992-7037.

Respectfully submitted, M. J. Ajluni Nuclear Licensing Director MJAlCLT /Iac

U. S. Nuclear Regulatory Commission NL-11-1652 Page 2

Enclosure:

1. Edwin I. Hatch Nuclear Plant 10 CFR 50.46 ECCS Evaluation Model Significant Change/Error Report cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. J. T. Gasser, Executive Vice President Mr. D. R. Madison, Vice President - Hatch Ms. P. M. Marino, Vice President - Engineering RTYPE: CHA02.004 U. S. Nuclear Regulatory Commission Mr. V. M. McCree, Regional Administrator Mr. P. G. Boyle, NRR Project Manager Mr. E. D. Morris, Senior Resident Inspector - Hatch

Edwin I. Hatch Nuclear Plant 10 CFR 50.46 ECCS Evaluation Model Significant Change/Error Report Enclosure 1 10 CFR 50.46 ECCS Evaluation Model Significant Change/Error Report to NL-11-1652 10 CFR 50.46 ECCS Evaluation Model Significant Change/Error Report Edwin I. Hatch Nuclear Plant Unit 1 SAFERIGESTR-LOCA Analysis Model Table 1-1a - Current Changes/Errors Estimated Description Effect (Ll PCT)

In GE Hitachi 10 CFR 50.46 Notification Letter 2011-02 (Reference 1) an error was reported regarding the input coefficients used to direct the deposition of gamma radiation energy produced by fuel causing the heat deposited in the fuel channel (post scram) 45 to be overpredicted and the corresponding heat to the fuel to be under predicted. The bounding effect of this error on peak cladding temperature (PCT) has been determined to be 45 of.

In GE Hitachi 10 CFR 50.46 Notification Letter 2011-03 (Reference 1) an error was reported that the contribution of heat from gamma ray absorption by the channel had been minimized.

The method had been simplified such that initially all the energy was assumed to be deposited in the fuel rods prior to the 5

loss-of-coolant accident (LOCA) and then adjusted such that the correct heat deposition was applied after the scram. The energy distribution during the pre-scram phase was updated with the appropriate energy distribution. The bounding effect of this error on PCT has been determined to be 5 of.

Table 1-1b - Cumulative Impact of Changes/Errors GE14 Description AIPCTI eF)

• Changes/Errors Previously Reported in Annual Report 5

(Reference 2)

• Current Changes/Errors (References 1, 3) 50 55 Cumulative Total E1-2

Enclosure 1 to NL-11-1652 10 CFR 50.46 ECCS Evaluation Model Significant Change/Error Report Edwin I. Hatch Nuclear Plant Unit 2 SAFERIGESTR-LOCA Analysis Model Table 1-2a - Current Changes/Errors Estimated Description Effect

(~ PCT)

In GE Hitachi 10 CFR 50.46 Notification Letter 2011-02 (Reference 1) an error was reported regarding the input coefficients used to direct the deposition of gamma radiation energy produced by fuel causing the heat deposited in the fuel channel (post scram) 45 to be overpredicted and the corresponding heat to the fuel to be under predicted. The bounding effect of this error on peak cladding temperature (PCT) has been determined to be 45 of.

In GE Hitachi 10 CFR 50.46 Notification Letter 2011-03 (Reference 1) an error was reported that the contribution of heat from gamma ray absorption by the channel had been minimized.

The method had been simplified such that initially all the energy was assumed to be deposited in the fuel rods prior to the 5

loss-of-coolant accident (LOCA) and then adjusted such that the correct heat deposition was applied after the scram. The energy distribution during the pre-scram phase was updated with the appropriate energy distribution. The bounding effect of this error on PCT has been determined to be 5 OF.

Table 1-2b - Cumulative Impact of Changes/Errors

• GE14 Description

~IPCTI (OF)

• Changes/Errors Previously Reported in Annual Report 5

(Reference 2)

• Current Changes/Errors (References 1, 4) 50 55 Cumulative Total E1-3 to NL-11-1652 10 CFR 50.46 ECCS Evaluation Model Significant Change/Error Report

References:

1. E-mail from James F. Harrison (GE Power & Water) to Christopher M.

Comfort (SNC), "Hatch Units 1 and 2 50.46 Notification Letters 2011-02 and 2011-03," dated July 21 , 2011.

2. Letter from Mark J. Ajluni to USNRC (NL-10-2340), "Edwin I. Hatch Nuclear Plant, Joseph M. Farley Nuclear Plant, Vogtle Electric Generating Plant 10 CFR 50.46 ECCS Evaluation Model Annual Reports for 2009," dated December 16, 2010

3. Global Nuclear Fuel Supplemental Reload Licensing Report for Edwin I.

Hatch Nuclear Power Plant Unit 1 (Report Number 0000-0099-0707-SRLR),

Revision 0, dated November 2009

4. Global Nuclear Fuel Supplemental Reload Licensing Report for Edwin I.

Hatch Nuclear Power Plant Unit 2 (Report Number 0000-0116-1536-SRLR),

Revision 0, dated December 2010 E1-4