ML20217F430

Responds to 991012 Rai,Based on 991001 Telcon Re Suppl to Request for TS Change to Revise MCPR Safety Limit & Add Approved Siemens Topical Rept for LaSalle County Station, Unit 1

ML20217F430
Person / Time
Site:	LaSalle
Issue date:	10/14/1999
From:	Jamie Benjamin COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9910200316
Download: ML20217F430 (7)

Text

'

Commonw ca!th I.dimn Comguny i

, , .*  !.a5alle Generating Mation 260i North 2Ist Road '

M.trsrilles 11. 6111 l W

^! cl H I 435' 6'6l l

l October 14,1999 U.S. Nuclear Regulatory Commission

' A1TN: Document Control Desk Washington, DC 20555 LaSalle County Station, Unit 1 I Facility Operating License No. NPF-11 NRC Docket No. 50-373

Subject:

Supplement to a Request for Technical Specification Change, to Revise MCPR Safety Limit and add an approved Siemens Topical Report for LaSalle County Station, Unit 1.

References; (1)' Letter from J. A. Benjamin (Comed) to U.S. NRC,

" Request for Technical Specification Change to Revise L. MCPR Safety Limit and add an approved Siemens

! Topical Report," dated July 7,1999.

(2) Letter from D. M. Skay (U.S. NRC) to O. D. Kingsley 1 (Comed), "LaSalle County Station, Unit 1 - Request fer 4

Additional Irhrmation (TAC No. MA6035)," dated Cetober 12,1999.

)

l .

In Reference 1,' Commonwealth Edison (Comed) Company requested approval of a license amendment for a Technical Specification (TS) change to revise the

' MCPR safety limit. In addition, the proposed change requested adding a NRC approved Siemens Topical Report.. The Topical Report was proposed to be added to TS Section 6.6.A.6.b," Core Operating Limit Reports," to allow use of

- this Siemens methodology in future core reload analysis. During the NRC technical branch review of the proposed change the NRC reviewer raised some L issues requiring clarification. These were discussed during a telephone L conference call on October 1,- 1999. Based on the phone conversation, the l . NRC issued a Request for Additional Information, (i.e., Reference 2). The

!- attachment to this letter provides our response to those questions.

The no~ significant hazards consideration, submitted in Reference 1, remains valid for the information attached. i

,. t 9910200316 hid14 I L PDR P -ADOCK 0500o373-PDR

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A OmCom Comp.t0}

October 14,1999

. U,.S. Nuclear Regulatory Commission Page 2 Should you have any questions concerning this letter, please contact Mr. Frank A. Spangenberg, Ill, Regulatory Assurance Manager, at (815) 357-6761, extension 2383.

I Respectfully,  !

i Jeffrey A. Benjamin 1 Site Vice President I LaSalle County Station y Attachment cc: Regional Administrator- NRC Region lli NRC Senior Resident inspector- LaSalle County Sta*.a l

I i

l l

i' STATE OF ILLINOIS )

IN THE MATTER OF )

COMMONWEALTH EDISON COMPANY )

LASALLE COUNTY STATION - UNIT 1 ) Docket No. 50-373 Subjecc - Supplement to a Request for Technical Specification Change, l '

to Revise MCPR Safety Limit and add an approved Siemens Topical Report for LaSalle County Station, Unit 1.

i AFFIDAVIT j i

l l affirm that the content of this transmittal is true and correct to the best of my j knowledge, information and belief.

l

,w A LL = ' -

pg] Jeffrey AQenjamin Site Vice President LaSalle County Station Subscribed and Eu,orn to before me, a Notary Pubjli in and for the State above named, this / day of /7 NM , /999 .

My Commission expires on / 2k .286/.

/

OFFlCIAL SLAL /[ f /),f/hf NOTAftY PLIC LLINOIS .// [ VNotary Public I MY CCWM80N EXPIRE $ 124-2001 1

l Attachmsnt Response to Request for Additionalinformation, Dated October 12,1999 By Letter from D. M. Skay (U.S. NRC) to O. D. Kingsley (Comed) dated October 12,1999, the NRC transmitted _two questions that require response.

The response is required in order to complete the review of the

' Technical Specification change request submittal, dated July 7,1999, related to a revision of the MCPR Safety Limit and addition of an approved Siemens Topical Report LaSalle County Station Unit 1. This attachment restates the NRC's questions and provides Comed's response. The references referred to in this attachment are listed at the end of the Attachment.

i Question 1: ,

1

" Provide the fuel types and numbers of assemblies used in the Cycle 8 and 9 core., and identify fresh or irradiated fuel (once or twice burned) for Cycles 8 and 9. Also, provide the loading patterns for both Cycles 8 and 9 and describe the differences and impact on the safety limit for minimum critical power ratio (SLMCPR) analysis."

Response

The fuel types, numbers of assemblies, and the loading patterns for Unit 1 Cycles 8(L1C8) and 9 (L1C9), including the cycles in which each fuel type was inserted into the core, are provided in References 1 and 2 of this Attachment. Excerpts from these documents that specify the core designs, are attached.

The differences between these two cycles that result in an impact on the SLMCPR analysis are driven by the fact that L1C9 is Unit 1's first cycle with ATRIUM-9B fuel and Siemens methodology, has a larger batch fraction, and is a 24-month operating cycle. This is stated in Attachment A, " Description and Safety Analysis for the Proposed Changes," Section D at the top of page  !

3 of 5 of the Technical Specification change request (Reference 3).

The batch size for L1C9 is 372 fresh ATRIUM-9B bundles and the batch size for L1C8 was 248 fresh GE9B bundles. The L1C8 cycle length will be approximately 11,700 mwd /MTU, compared to the L1C9 cycle length of 18,000 mwd /MTU. These larger batch sizes and cycle exposures are a result of L1C9 operation going to 24 month operating cycles and anticipating a 5% core thermal power uprate to be implemented mid-cycle (Reference 8). l These changes to L1C9 cause the radial power distribution to be flatter than  !

the L1C8 power share, which results in a higher SLMCPR.

Page 1 of 4

Additionally, L1C8 is comprised entirely of GE9B fuel and was licensed under the GE SLMCPR methodology. L1C9 uses a reload of ATRIUM-9B j fuel and Siemens Power Corporation (SPC) SLMCPR methodology. Fuel j design inputs to the SPC SLMCPR analysis include local power peaking j (exposure dependent), ANFB additive constants, and the additive constant l uncertainty.

i Question 2:

l

" Identify approved methodologies used for the SLMCPR analysis and the company that performed the analysis. Describe the SLMCPR calculation procedures for Cycles 8 and 9, and identify the differences i between the two; especially for the Cycle 9, which is a mixed core of GE fuel and Siemens fuel."

Response

Unit 1 Cycle 8 (L1C8) was initially licensed under GE's GESTAR methodology in 1995 based upon a GE9B fuel product line specific SLMCPR. Later, GE and the NRC recognized the fuel type dependent SLMCPR calculations to potentially be non-conservative without l consideration of the actual power distributions for the core to be licensed and )

the L1C8 core was reanalyzed with plant specific information. The SLMCPR in place at that time (1.07) was still supported, until the reanalyses for L1C9 were performed.

The SPC SLMCPR methods are described in Reference 4, which use the ANFB critical pow, r correlation described in Reference 5. The SLMCPR is established to ensure that 99.9% of the fuel rods in the core are expected to  !

avoid boiling transition during the limiting transient event. The SLMCPR is I determined through a statistical convolution of the uncertainties associated with the parameters used in calculating MCPR. These uncertainties include ,

fuel, monitoring, and plant measurement uncertainties (such as feedwater flow, core flow, and radial bundle power.) The SLMCPR is calculated based on parameters dependent on the fuel design and core design (loading pattern, control rod patterns, cycle exposure). Since L1C9 is a mixed core of i SPC ATRIUM 9B and GE9B fuel, the methodology described in Reference 4 specifically incorporates the use of the NRC approved ANFB uncertainties for ATRIUM 98 fuel (Reference 6), and the NRC approved methodology for applying the ANFB critical power correlation and associated uncertainties to the co-resident GE9B fuel (Reference 7).

Page 2 of 4

Because the foal and coro design may vary each cyclo, the supportable SLMCPR is calculated on a cycle specific basis. Should the supportable SLMCPR be higher than the value presented in the Technical Specifications, a Technical Specification Amendment would be requested of the NRC (e.g.

as was done for L1C9).

l The differences between L1C8 and L1C9 that were discussed in Question 1 j above are sufficient to affect the calculated safety limit by an increase of 1.07 '

to 1.11. Dresden 2 Cycle 17 (D2C17) will require a MCPR Safety Limit of 1.12. Therefore, L1C9 is demonstrating similar trends in MCPR Safety Limit as D2C17.

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l Page 3 of 4

Reference,:

1. "LaSalle 1 Cycle 9 Core Design", NDIT NFM9900388, September 23,1999.

2. GE document, Supplemental Reload Licensing Report for LaSalle County Station Unit 1 Reload 7 Cycle 8,24A5180, Rev.1, May 1998.

3. Letter from J. A. Benjamin (Comed) to U.S. NRC, " Request for Technical Specification Change to Revise MCPR Safety Limit and add an approved Siemens Topical Report,' dated July 7,1999.

4. Advanced Nuclear Fuels Corporation Critical Power Methodology for Boiling Water Reactors / Advanced Nuclear Fuels Corporation Critical Power Methodology for Boiling Water Reactors: Methodology for Analysis of Assembly Channel Bowing Effects /NRC Correspondence, XN-NF-524(P)(A) Revision 2, and Supplement 1 Revision 2, Supplement 2, Advanced Nuclear Fuels Corporation, November 1990.

(LaSalle Unit 1 Technical Specification 6.6.A.6.b.(3), approved by Unit 1 License Amendment 116*)

5. ANFB Critical Power Correlation, ANF-1125(P)(A) and Supplements 1 and 2, Advanced Nuclear Fuels Corporation, April 1990. (LaSalle Unit 1 Technical Specification 6.6.A.6.b.(1), approved by Unit 1 License Amendment 116*)

6. ANFB Critical Power Correlation Determination of ATRIUM 9B Additive Constant Uncertainties, ANF-1125 (P)(A), Supplement 1, Appendix E, Siemens Power Corporation, September 1998. (LaSalle Unit 1 Technical Specification 6.6.A.6.b.(25), approved by Unit 1 l License Amendment 131*)

7. ANFB Critical Power Correlation Application for Coresident Fuel, EMF-1125(P)(A), Supplement 1, Appendix C, Siemens Power Corporation, August 1997. (LaSalle Unit 1 Technical Specification , 6.6.A.6.b.(24), approved by Unit 1 License Amendment 131*) i

.8. Letter from R.M. Krich (Comed) to U.S. NRC, " Request for License Amendment for Power Uprate," dated July.14,1999.**

• LaSalle County Station Facility License Amendments 116 and 131 were approved and made effective upon the date of issuance, October 29,1996 and March 16,1999, respectively. The amendments will be implemented as required during refueling outage L1R08 and prior to startup for LaSalle Unit 1 Cycle 9.

• • Power uprate will be imp'emented following approval and issuance of the

- License Amendments.

Page 4 of 4

4 C)s 1

GE Nuclear Energy 24A5100 Revision 1 Class I ,

May 1998 - i 24A5180, Rev.1 Supplemental Reload Licensing Report for LaSalle County Station Unit 1 I Reload 7 Cycle 8 i

i Approved Approved b G. A. atford, Manager W. H. Hetzel 9'" #  !

Nuclear Fuel Engineering Fuel Project Manager i

i 2

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LASALLE1 24A5180 Reload 7 Rev.1 ,

i The basis for this seport is GeneralElectric Standard Applicationfor Reactor Fuel, NEDE-240l 1-P-A-11, l November 1995; and the U.S. Supplement, NEDE-240ll-P-A-ll-US, November 1995.

1. Plant-unique Items Appendix A: Analysis Conditions l Appendix B: Impact of Change to the APRM Flux Scram Setpoint

2. Reload Fuel Bundles l'

l Cycle Fuel Type Loaded Number Irradiated: ,

GE9B-P8CWB303-9GL100M-150-T (GE8x8NB) 5 108

! GE9B-P8CWB 313-9GL100M-150-T (GE8x8NB) 6 128 i I

GE9B-P8CWB314-9GZ-100M-150-T (GE8x8NB) 6 72 GE9B-P8CWB322-I lGL100M-150-T (GE8x8NB) 7 104 G E9 B-P8 CWB 320-9GZ3- 100M-150-T (G E8 x 8 NB) 7 104

&2G 1

1 GE9B-P8CWB342-10GL80M-150-T (GE8x8NB) 8 144 GE9B-P8CWB343-120Z-80M-150-T (GE8x8NB) 8 104 Total 764

3. Reference Core Loading Pattern l

Nominal previous cycle core average exposure at end of cycle: This information will be  !

provided by Comed  ;

Minimum previous cycle wie average exposure at end of cycle This information will be {

from cold shutdown considerations: provided by Comed l Assumed reload cycle core average exposure at beginning of 15680 mwd /MT cycle: ( 14225. mwd /ST) l Assumed reload cycle core average exposuit at end of cycle: 27365 mwd /MT

( 24825 mwd /ST)

Reference core loading pattem: Figure 1 Page 4

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d NFM:BND:99-031 Attachment 1 Page 1 of 3 L1C9 FULL CORE FUEL TYPE IGP 1 2 3 4 5 6 7 8 9101112131415161718192021222324252627282930 1' 1 2222 1 2222 2 22 i 2 1 5 8 8 9598 8 95 988 5 1 3 1 1 4 9 6TT7 6 4 4 67 8 5 694 1 1 4 2 99 6 5 1 4 65 66 5 6 4 1 569 92 5 2 4 67 5'7 67 5 67 7 657 67 57 652 6 1 2 4 8 -4 6 65 4 664 55 4 6 64 56 6 4 8 4 2 1 7 1 9 6 4 25 67 2 5 64 22 4 6 52 7 6 52 4 691 8 1 4 97 6 52 5 6 5 6 7 6 4 4 67 65 65 25 67 9 4 1 9 1 59 65 6 657 667 4 7 667 4 7 667 5 6 65 695 1 10 2 8 657 57 6 6 4 5 65 64 4 65 6 5 4 6 67 57 568 2 11 2 8 5 1 6 4 2 5 65 1 5 67 2 2 7 6 5 1 5 6 52 4 6 1 5 82 12 2 9 8-4 7 6 5 6 7 6 5 1 5 6 55 65 1 5 67 65 67 4 8 92 13 2 57 6 5 6 67 4 5 65 4 66 6 64 5 65 4 7 6 65 67 52 14 1 965 6 4 4 6 7 67 6 67 4 4 7 6 67 67 64 4 65 69 1 15 2 8 4 6 7 5 24 64 2 5 64 2 2 4 6 5 2 4 6 4 2 57 64 8 2 16 2 8 4 6 7 5 2 4 6 4 2 5 64 22 4 6 5 2 4 6 4 2 57 64 8 2 17 1 96 5 64 4 67 67 6 67IT7 6 67 67 6 4 4 6569 1 18 2 57 65 667 4 5 65 4 6 66 64 5 654 7 6 65 67 52 l

19 2 9 8 4 7 6 56 7 6 5 1 5 6 55 65 1 5 67 6 5 67 4 8 92 20 28 52 6 4 2 5 65 1 S t 67 2 2 7 6 5 1 5 6 52 4 6 1 5 8 2 21 2 8 6 4 7 4 7 6 6' 4 5 65 6 4 4 65 65 4 6 67 57 5 68 2 22 1 59 6 5 6 657 6 67 4 7 667 4 7 667 5 6 65 695 1

23 1 4 97 6 51 5 6 56 7 6 4 4 67 6 5 65 2 5 67 9 4 1 24 2 9 6 4 1 5 67 2 5 64 1 2 4 6 52 7 6 52 4 6 9 1 l 25 1 2 5 8 4 664 4 6 64 554 6 64 5 6 64 8 4 2 1 i 26 2 1 67 5 7 67 567 7 657 67 57 6 4 2 27 2 9965 1 4 65 66 56 4 1 5 6 99 2 28 1 1 4 96 58 7 6 4 4 67 8 5 694 1 1 29 1 5 8 8 95 98I95 9 8 8 5 1 30 1 2 2 22 2 2 2 1 22 22 1 1 2 3 4 5 6 7 8 9101112131415161718192021222324252627282930 Nuclear Num',or Cycle Type Channel Serial Number Range Fuul Type Fresh Thickness 1 56 7 GE9B 100M YJ8051 - YJ8154 2

89 7 GE9B 100M YJ7947 - YJ8050 4 104 0 GE9B 80M YJD661 - YJD764 5 143 8 CE9B 80M YJD517 - YJD660 i 6 208 9 ATRIUM 9B 100M 19A001 - 19A208 7 88 9 ATRIUM 9B 100M 19B209 - 19B296 8 36 9 ATRIUM 93 80M 28B257 - 2BB292 i 9 40 9  ! ATRIUM 93 100M 19C297 - 13C336 i 0

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