Part 21 Report - 1997-471

ACCESSION #: 9706300063 SIEMENS June 26, 1997 HDC:97:062 Document Control Desk ATTN: Chief, Planning, Program and Management Support Branch U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Interim Report of Evaluation of a Deviation Pursuant to 10 CFR 21.21 (a)(2) The following information is provided pursuant to the requirements of 10 CFR 21 to submit an interim report on issues that will not be completed within 60 days of discovery. Three interim reports are enclosed for the following issues under evaluation by Siemens Power Corporation: 97-001 "Fraction of Power in Hot Rod for LBLOCA and SBLOCA Voided Core Calculations" 97-002 "Robinson Shutdown Margin and Steam Line Break" 97-003 "Error in Local Power Distribution and View Factors for Gadolinia Fuel in LBLOCA Radiation Model" Interim report number 97-001 was previously forwarded to the NRC on June 9, 1997 with an incorrect completion date. The correct completion date is August 8, 1997. If there are any questions, please contact me. Very truly yours, H. Donald Curet, Manager Product Licensing /smg Enclosure cc: E. Y. Wang (NRR/DRPM/PECB) Siemens Power Corporation Nuclear Division 2101 Horn Rapids Road Tel: (509) 375-8100 Engineering & Manufacturing P.O. Box 130 Fax: (509) 375-8402 Richland, WA 99352-0130 Interim Report (97-001) Subject: Interim report of evaluation of a deviation pursuant to 10 CFR 21.21 (a)(2) Title: Fraction of Power in Hot Rod for LBLOCA and SBLOCA Voided Core Calculations Identification of Basic Activity: 10 CFR 50.46 PWR ECCS Evaluation Model Basic Activity Supplied By: Siemens Power Corporation - Nuclear Division Nature of Deviation: The fraction of the power deposited in the hot rod under voided core conditions may be non-conservative Discovery Date: April 21, 1997 Corrective Actions to Date: Nonconformance report (NCR-6090) prepared and processed by management review team as required by SPC-ND's Quality Assurance Manual, EMF-1. Analyses have been performed which demonstrate that the fraction of power deposited in UO2 fuel rods under voided core conditions is conservative, but the fraction of power deposited in gadolinia bearing fuel rods may be non-conservative. Calculations for gadolinia bearing fuel rods are in progress to verify 10 CFR 50.46(b) criteria are satisfied. This issue is judged not to be a substantial safety hazard. Evaluation Completion Schedule Date: August 8, 1997 (Revised from June 27, 1997) Interim Report (97-002) Subject: Interim report of evaluation of a deviation pursuant to 10 CFR 21.21 (a) (2) Title: Robinson Shutdown Margin and Steam Line Break Identification of Basic Activity: 10 CFR 50.46 PWR ECCS Evaluation Model Basic Activity Supplied By: Siemens Power Corporation - Nuclear Division Nature of Deviation: A Steam Line Break shutdown margin requirement for a hot shutdown condition of 1.0% delta-k/k at a boron concentration of 640 ppm does not appear to have any documented justification. Discovery Date: May 20, 1997 Corrective Actions to Date: Nonconformance report (NCR 61 25) was prepared and processed by the management review team. CP&L was informed of the deviation, and it has been determined HBR has administrative procedures that limit operations to the conservative shutdown margin conditions of 1.77% delta-k/k at boron concentrations of 0.0 ppm used as input to the Steam Line Break analysis. Evaluation Completion Schedule Date: October 31, 1997 Interim Report (97-003) Subject: Interim report of evaluation of a deviation pursuant to 1 0 CFR 21.21 (a)(2) Title: Error in Local Power Distribution and View Factors for Gadolinia Fuel in LBLOCA Radiation Model Identification of Basic Activity: 10 CFR 50.46 PWR ECCS Evaluation Model Basic Activity Supplied By: Siemens Power Corporation - Nuclear Division Nature of Deviation: SPC has discovered an error in the LBLOCA calculations for the gadolinia fuel at Robinson and Harris. The local peaking distribution used in the radiation model for gadolinia fuel in Harris was non-conservative. For Harris and Robinson, the radiation view factors for the UO2 peak power rod were inadvertently used for the gadolinia rods. This is non- conservative because the UO2 fuel rods are face-to-face with the guide tubes, but the gadolinia rods are on the diagonal to the guide tubes (i.e., smaller view factor for the heat sink). Discovery Date: May 29, 1997 Corrective Actions to Date: Nonconformance report (NCR 6141) was prepared and processed by the management review team. CP&L was informed of the deviation, and it has been determined that for both Harris and Robinson the errors are not anticipated to cause the peak cladding temperature for the gadolinia rods to be higher than limiting PCT for UO2 rods. Evaluation Completion Schedule Date: August 22, 1997 *** END OF DOCUMENT ***

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