ML032481193

Response to Request for Additional Information Regarding Steam Generator Replacement & Power Uprate License Amendment Request

ML032481193
Person / Time
Site:	Palo Verde
Issue date:	08/22/2003
From:	Mauldin D Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-04989-CDM/TNW/RMW
Download: ML032481193 (4)

Text

David Mauldin Vice President Mail Station 7605 Palo Verde Nuclear Nuclear Engineering TEL (623) 393-5553 P.O. Box 52034 Generating Station and Support FAX (623) 393-6077 Phoenbi AZ 85072-2034 102-04989-CDM/TNW/RMW August 22, 2003 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555

References:

1. Letter No. 102-04641 -CDMIRAB, dated December 21, 2001, from C. D. Mauldin, APS to U. S. Nuclear Regulatory Commission, "Request for a License Amendment to Support Replacement of Steam Generators and Uprated Power Operations".

2. ABB Combustion Engineering Nuclear Fuel Topical Report CEN-386-P-A,

'Verification of the Acceptability of a 1-Pin Bumup Limit of 60 MWD/kgU for Combustion Engineering 16x16 PWR Fuel", dated August 1992.

3. NRC Letter from Ashok C. Thadani, USNRC, to Mr. A. E. Scherer, Combustion Engineering, dated June 22,1992, "Generic Approval of C-E Topical Report CEN-386-P-A, 'Verification of the Acceptability of a 1-Pin Bumup Limit of 60 MWD/kgU for Combustion Engineering 16x16 PWR Fuel" (TAC NO. M82192)".

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 2, Docket No. STN 50-529 Response to Request for Additional Information Regarding Steam Generator Replacement and Power Uprate License Amendment Request In Reference 1, Arizona Public Service Company (APS) submitted a license amendment request to support steam generator replacement and uprated power operations for PVNGS Unit 2. During a conference call held between the NRC staff and APS on August 15, 2003, the staff requested additional information regarding cladding oxidation for zircaloy-clad fuel. This Information can be obtained from Figure 4.1.2.a-1, Oxide vs. Bumup, page 8, of Reference 2. Please note the following with respect to the information provided in this figure and Reference 2:

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• South Texas Project

• Wolf Creek

U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Response to Request for Additional Information Regarding Steam Generator Replacement and Power Uprate License Amendment Request Page 2

1.

The information contained in Reference 2 is ABB Combustion Engineering Nuclear Fuel (now Westinghouse Electric Company LLC) proprietary information,

2.

Reference 2 has received generic NRC approval as documented in Reference 3,

3.

Fuel rod details are provided on page 73 of Reference 2, Table 4.2.7.a-1, and

4.

The oxide information provided in Figure 4.1.2.a-1 must be converted from oxide thickness into the percent amount of zircaloy cladding wastage that occurs when oxidation occurs. This conversion process is described below.

Oxide thickness, In microns, can be converted into the percent amount of zircaloy cladding wastage using the following equations:

Zircaloy cladding wastage (pm) = oxide thickness (gm)/1.56 (based on information taken from Figure 4.1.2.a-1 of Reference 2, and the volumetric difference between zircaloy cladding oxide and pure zircaloy cladding. One oxide molecule occupies 1.56 times as much volume as one pure zircaloy cladding molecule)

Original zircaloy cladding thickness (gim) = original zircaloy cladding thickness (mils) x 25.4 (original zircaloy cladding thickness can be determined from information provided in Table 4.2.7.a-1 of Reference 2, and on the conversion factor of 1 mil = 25.4 gm)

Percent zircaloy cladding wastage = (zircaloy cladding wastage (pm)/original zircaloy cladding thickness (gm))xM00 An example of the above conversion process Is provided below. Assume that the initial zircaloy cladding thickness is 25 mils and that the oxide thickness, in microns, for a rod average bumup of 40 MWD/kgU has been determined to be 40 prm from Figure 4.1.2.a-1. Note that these assumed values are for illustration purposes only and they may not be representative of the actual values provided in Reference 2.

Zircaloy cladding wastage (pm) = 40 pm/1.56 = 25.64 pm Original zircaloy cladding thickness (gm) = 25 mils x 25.4 Wm/mil = 635 gm Percent zircaloy cladding wastage = (25.64 pm/635 pm)xl 00 = 4.04%

As can be seen from this example, determining the percent amount of zircaloy cladding wastage from the information provided in Reference 2 is a straightforward conversion process.

U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Response to Request for Additional Information Regarding Steam Generator Replacement and Power Uprate License Amendment Request Page 3 This letter does not contain any proprietary information, nor are any commitments being made to the NRC in this letter.

Should you have any questions, please call Thomas N. Weber at (623) 393-5764.

Sincerely, CDM/TNW/RMW cc:

Regional Administrator J. N. Donohew M. B. Fields N. L. Salgado A. V. Godwin

Attachment:

1.

Notarized Affidavit (NRC Region IV)

(NRR Project Manager)

(NRR Project Manager)

(NRC Senior Resident Inspector)

(ARRA)

STATE OF ARIZONA COUNTY OF MARICOPA

) Ss.

1, David Mauldin, represent that I am Vice President Nuclear Engineering and Support, Arizona Public Service Company (APS), that the foregoing document has been signed by me on behalf of APS with full authority to do so, and that to the best of my knowledge and belief, the statements made therein are true and correct.

David auldin Sworn To Before Me This '2 Day Of OFFn SEAL Karen D. Greiner iTARY PUBLIC -STATE of iAPsZ MARICOPA0UNTY MY CCUI EXPRES DJJCUST 28, 2004 I Al&e I

2003.

Notary Commission Stamp