ML040760831

Additional Information Regarding Mixed Oxide Fuel Lead Assemblies Criticality

ML040760831
Person / Time
Site:	Catawba
Issue date:	03/09/2004
From:	Barron H Duke Energy Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC MB7863, TAC MB7864
Download: ML040760831 (7)

Text

_kDuke WdPower.

A Duke EneryJ Company Duke Power Energy Center P.O. Box 1006 Charlotte, NC 28201-1006 March 9,2004 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555

Subject:

Duke Energy Corporation Catawba Nuclear Station Units 1 & 2, Docket Nos. 50-413, 50-414 Additional Information Regarding Mixed Oxide Fuel Lead Assemblies Criticality (TAC Nos. MB7863, MB7864)

By letter dated February 27, 2003 Duke Energy submitted an application to amend the licenses of McGuire and Catawba to allow the use of four mixed oxide fuel lead assemblies.

The NRC staff discussed additional questions with Duke Energy in a teleconference on February 5, 2004.

Attachment I to this letter provides the formal response to those questions.

Inquiries on this matter should be directed to Michael T. Cash at (704) 382-5826.

HB Barron Executive Vice President - Nuclear Generation Duke Energy Corporation A uo (

attachments

cc: v/attachment L. A. Reyes U. S. Nuclear Regulatory Commission Regional Administrator, Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, GA 30303 R. E. Martin (addressee only)

NRC Project Manager U. S. Nuclear Regulatory Commission Mail Stop O-8G9 Washington, DC 20555-0001 E. F. Guthrie Senior Resident Inspector U. S. Nuclear Regulatory Commission Catawba Nuclear Station J. B. Brady Senior Resident Inspector U. S. Nuclear Regulatory Commission McGuire Nuclear Station Diane Curran Harmon, Curran, Spielberg & Eisenberg, LLP 1726 M Street, N.W.

Suite 600 Washington, DC 20036 Mary Olson Director, Southeast Office Nuclear Information and Resource Service P.O. Box 7586 Asheville, NC 28802 H. J. Porter, Director Division of Radioactive Waste Management Bureau of Land and Waste Management Department of Health and Environmental Control Columbia, SC 29201

bcc: attachment Richard Clark-DCS Patrick Rhoads-DOE David Alberstein-DOE Don Spellman-ORNL NCMPA-1 NCEMC PMPA SRE bcc: w/attachment (via email)

S. P. Nesbit M. T. Cash F. J. Verbos J. L. Eller S. P. Schultz L. F Vaughn M. W. Scott L. J. Rudy J. Hoerner-Framatome ANP G. A. Meyer - Framatome ANP bcc: 'w/attachments (paper copy)

NRIA File/ELL - ECO50 MOX File 1607.2304 Catawba Document Control File 801.01-CN04DM Catawba RGC Date File (J. M. Ferguson - CN0 I SA)

Oath and Affirmation I affirm that I, HB Barron, am the person who subscribed my name to the foregoing, and that all the matters and facts set forth herein are true and correct to the best of my knowledge.

HB Barron Subscribed and sworn to before me on this T7r4 day of _

,clt-go CoX "O

T-, 4Le Notary Public My Commission expires:

MICHAEL T. CASH Notary Public Lincoln County, North Carolina Commission Expires January 22, 2008 Date Duke Responses to Additional MOX LTA Criticality Questions (from 2/5/04 NRC Telecon)

1. In Table A3-3 of the submittal, results from 28 MOX critical experiments are listed. However, in the supporting text on page A3-6, which describes the critical experiments, a total of only 27 critical experiments are discussed. Please explain this discrepancy.

In the last full paragraph on page A3-6, the text states that 17 MOX experiments varied water level to approach criticality. These 17 experiments correspond to the MIX-COMP-THERM-003 and MIX-COMP-THERM-004 sets of critical experiments shown in the list on page A3-6. According to this list, which notes 7 experiments for MIX-COMP-THERM-003 and 11 experiments for MIX-COMP-THERM-004, the combined total for these series should be 18 experiments. However, the MIX-COMP-THERM-003 series actually comprises only six (6) physically different models. One of the experiments in this series was carried out at two different water temperatures, and so yielded an additional "experiment" that was also included in Table A3-3 (see mctO03-02 and mctO03-03), and considered for the development of the overall method bias and uncertainty shown at the bottom of Table A3-3.

2. How many neutron generations were used in the SCALE 4.4/ KENO V.a computational cases for the MOX critical experiments in Table A3-3?

400 neutron generations were counted in each of the critical experiment cases summarized in Table A3-3.

3. How are the method bias and method uncertainty (shown below Table A3-3 on page A3-7) calculated?

The method bias and uncertainty are calculated as shown below.

Method Bias BiasjeAO = (

V) x E (K

.Afetho (-

x (Ki - kj E)

N 1

NxZ (kki~g 2

N 2

Method Uncertainty U1CA9ethod =

-9595 X l VARM (V - 1) xEc I (N-~I x>3-

W 'here:

Nk U2 kavg =

OI N =

U2i N

ZUi2 (x

NG1)

VAR 2

ZNG.

and ki

= KENO calculated kff for critical experiment i a,

= Monte Carlo standard deviation for critical experiment i NG;

= number of neutron generations used in Monte Carlo analysis for critical experiment i N

= number of critical experiments (28)

K;

= measured value of k~ff for critical experiment i f95195

= one-sided 95/95 tolerance factor for 28 critical experiments (2.246)

4. On page A3-8, a nominal model is discussed. What does the nominal model refer to?

In its November 3, 2003 letter to the NRC, Duke provided the following response to question #41 of the July 25, 2003 RAI. This response addresses the nominal model:

The nominal model refers to the nominal specifications for the Mark-BW/MOX1 fuel assembly, the highest-reactivity LEU fuel assembly, and the spent fuel pool storage racks. The MOX and LEU fuel assembly model data are provided in Table 3-1 of Attachment 3 of Reference Q41-1. For the SCALE 4.4 IKENO V.a model of the MOX and LEU fuel assemblies, average fuel stack densities of 10.32 grams/cc and 10.34 grams/cc for MOX fuel and LEU fuel, respectively, were derived from the data in Table 3-1. Spent fuel pool storage rack information (including thickness and pitch for the stainless steel rack cells) is shown in Table A3-1 in Appendix 3-1. The isotopic composition for the nominal MOX fuel lead assembly is given in Table A3-2 in Appendix 3-1. As noted on page A3-12, the criticality analysis conservatively maximized the fissile plutonium content of the Table A3-2 data.

5. On page A3-9 the total 95195 keff equation is shown. Please provide a reference for this equation.

The equation shown on page A3-9 is based on the maximum keff equation on page 4 of the August 19, 1998 NRC Kopp memorandum. The various uncertainty components for the MOX criticality calculations (see Table A3-4) are combined statistically, as they are considered independent variations from the nominal model.