NG-99-0678, Application for Amend to License DPR-49,revising SLMCPR to Support Operation with GE-12 Fuel with 10x10 Pin Array

Application for Amend to License DPR-49,revising SLMCPR to Support Operation with GE-12 Fuel with 10x10 Pin Array

ML20206P723
Person / Time
Site:	Duane Arnold
Issue date:	05/10/1999
From:	Franz J IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20206P730	List: ML20206P740 NG-99-0678, Application for Amend to License DPR-49,revising SLMCPR to Support Operation with GE-12 Fuel with 10x10 Pin Array
References
RTR-NUREG-0800, RTR-NUREG-800 NG-99-0678, NG-99-678, NUDOCS 9905180296
Download: ML20206P723 (6)

Text

e s g UTILITIESALLI ANT its uuniie inc.

Duane Arnold Energy Center IES Utilities 3m oAEc wa Palo,IA 52324-97H5 Office: 319.851.761 I rax; 319.851.79%

May 10,1999 www.aihani energuom NG-99-0678 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station 0-Pl-17 Washington, DC 20555-0001

Subject:

Duane Arnold Energy Center Docket No: 50-331 Op. License No: DPR-49 {

l Technical Specification Change Request (TSCR-021): i

" Revised Safety Limit Minimum Critical Power Ratio"

Reference:

Letter NG-99-0049, dated January 22,1999, Franz (lES) to NRC, TSCR-007: " Spent Fuel Racks Storage Update" File: A-117

Dear Sir (s):

In accordance with the Code of Federal Regulations, Title 10, Sections 50.59 and 50.90, IES Utilities Inc. hereby requests revision to the Technical Specifications for the Duane Arnold Energy Center (DAEC).

The proposed amendment revises the Safety Limit Minimum Critical Power Ratio (SLMCPR) to support operation with GE-12 fuel with a 10x10 pin array. The General Electric letter which suppons this change request is included with this submittal as Attachment 5. A proposed amendment to support storage of GE-12 fuel in the Spent Fuel Pool was submitted via the above referenced letter.

This application has been reviewed by the DAEC Operations Committee and the Safety Committee. A copy of this submittal, along with the 10CFR50.92 evaluation of"No Significant Hazards Consideration", is being forv arded to our appointed state official pursuant to 10 CFR Section 50.91.

1 We request approval of this application no later than October 1,1999 to ensure  !

implementation prior to the scheduled start of Cycle 17. We also request that the effective date be no earlier than the date of shutdown for the Cycle 16/17 refuel outage, currently scheduled for October 8,1999, to avoid unnecessary conflicts with the current cycle's (i.e., I Cycle 16) operating limits.

D The analysis discussed in Attachment 5 is dependent upon the final core loading pattern. The loading pattern used in this analysis has not yet been confirmed to meet all its design acceptance criteria. This confirmation is expected to be completed in June,1999. Because we 9905180296 990510 PDR ADOCK 05000331 P PDR j

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. NG-99-0678 May 10,1999 Page 2 do not expect the proposed values for the SLMCPR to change, we chose to docket this at the earliest possible date to allow the staff adequate time to review this application. If there is a change to the SLMCPR, we will promptly notify the staff and update this submittal.

This letter is true and accurate to the best of my knowledge and belief.

IES UTILF lES INC By John F. Franz Vice President, Nuclear State ofIowa (County) of Linn Signed and sworn to before me on this /0 day of MGM ,1999, by hT//d b. Nik60Yi Yameu .)t~}Aauck Notah Public ih and for the State ofIowa NANCY S. FRANtK

-((-C/

Commission Expires Attachments: 1) EVALUATION OF CHANGE PURSUANT TO 10 CFR SECTION 50.92

2) PROPOSED CHANGE TSCR-021 TO TIIE DUANE ARNOLD ENERGY CENTER TECHNICAL SPECIFICATIONS

3) SAFETY ASSESSMENT

4) ENVIRONMENTAL CONSIDERATION

5) GENERAL ELECTRIC LETTER JDK/jdk cc: J. Kerr E. Protsch (w/o)

D. Wilson (w/o)

B. Mozafari (NRC-NRR)

J. Dyer (Region III)

P. Baig (State ofIowa)

NRC Resident Office Docu

. TSCR-021 Attachment I to NG-99-0678 PageIof4 EVALUATION OF CHANGE PURSUANT TO 10 CFR SECTION 50.92

Background:

The Duane Arnold Energy Center (DAEC) Technical Specifications for the Safety Limit Minimum Critical Power Ratio (SLMCPR), Section 2.1.1.2, are written for the currently-used GE-10 fuel which contains pins in 8x8 arrays.' With the introduction of GE-12 fuel (10x10 array) to support DAEC Cycle 17 operation, an analysis has been performed using L NRC-approved methods to support a change in the Technical Specification SLMCPR as discussed in General Electric letter TGR:99-004, dated April 12,1999. A copy of this letter is included with this submittal as Attachment 5.

The Updated Final Safety Analysis Report (UFSAR) Safety Design Bases, (Section 4.4, Thermal-Hydraulic Design) . states that the thermal-hydraulic design of the core shall establish the safety limits for use in evaluating the safety margin relating the I consequences of fuel barrier failure to public safety.

As discussed in the Technical Specification 2.1.1.2 BASES, the fuel cladding integrity

' Safety Limit (SL) is set such that no significant fuel damage is calculated to occur if the limit is nat violated. Since the parameters that result in fuel damage are not directly observable during reactor operation, the thermal and hydraulic conditions that result in the onset of transition boiling have been used to mark the beginning of the region in which fuel damage could occur. Although it is recognized that the onset of transition boiling would not result in damage to BWR fuel rods, the critical power at which transition boiling is calculated to occur has been adopted as a convenient limit. However, the uncertainties in monitoring the core operating state and in procedures used to calculate the critical power result in an uncertainty in the value of the critical power.

Therefore, the fuel cladding integrity SL is defined as the critical power ratio in the limiting fuel assembly for which more than 99.9% of the fuel rods in the core are expected to avoid transition boiling, considering the power distribution within the core and all uncertainties. This is consistent with Section 4.4 of the Standard Review Plan, NUREG 0800.

The SLMCPR is determined using a statistical model that combines all the uncertainties in operating parameters and the procedures used to calculate critical power. The probability of the occurrence of transition boiling is determined using the approved General Electric Critical Power correlations. Details of the fuel cladding integrity SL calculation methodology are given in Amendment 25 to NEDE-24011-P-A," General Electric Standard Application for Reactor Fuel"(GESTAR-II). Also included is a tabulation of the 9.ncenainties used in the determination of the SLMCPR and of the nominal values ( f the parameters used in the SLMCPR statistical analysis.

Attachment 5 provides the SLMCPR to support operation with GE-12 fuel. The calculations, which consider the impact on SLMCPR of the combined GE-12 and GE-10 j

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. TSCR-021 Attachment I to NG-99-0678 Page 2 of 4 core, show that an increase in SLMCPR is necessary. The SLMCPR for two recirculation loop operation is increasing from 1.07 to 1.09. During Single Loop Operation (SLO), the SLMCPR must be increased by 0.01 over that for two recirculation loop operation to account for the increased uncertainty in the core flow and Traversing in-Core Probe readings. The SLMCPR for SLO is increasing from 1.08 to 1.10. All applicable conditions of the cycle specific SLMCPR process and method as specified in the Staff's approval of Amendment 25 to GESTAR-Il have been satisfied.

The fuel to be used in the reactor at the start of Cycle 17 is comprised of the following:

. 120 bundles of GE-10 (8x8) burned one cycle

. 120 bundles of GE-10 (8x8) burned two cycles e 48 new btmdles of GE-12 (10x10) Design GE12-P10DSB370-14GZ-100T-150-T e 80 new bundles of GE-12 (10x10) Design GE12-P10DSB371-12GZ-100T-150-T These new bundle designs comply with the NRC's requirements in their approval of Amendment 22 to GESTAR-ll.

IES Utilities Inc.. Docket No. 50-33_Jl Duane Arnold Enercy Center. Linn County. Iowa Date of Amendment Reauest: May (O.1999 Description of Amendment Reauest:

The existing wording in Section 2.1.1.2 shall be deleted and replaced with the following:

MCPR - With the reactor steam dome pressure 2 785 psig and core flow 210%

rated core flow:

MCPR shall be 21.09 for two recirculation loop operation or 21.10 for single recirculation loop operation.

Basis for proposed No Sienificant 11azards Consideration: i 1

l The Commission has provided standards (10 CFR Section 50.92(c)) for determmmg

)

whether a significant hazards consideration exists. A proposed amendment to an i operating license for a facility involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated; (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

r s )

TSCR-021 Attachment I to 1 .

1 NG-99-0678 Page 3 of 4 After reviewing this proposed amendment, we have concluded:

1. The proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated.

i There is no change to any plant equipment other than the fuel. The SLMCPR protects

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the fuel in accordance with the design bases. The SLMCPR calculations limit the bundle power to ensure the critical power ratio remains unchanged. Therefore, there is {

not an increase in the probability of transition boiling. The basis of the SLMCPR calculation remains the same, ensuring that greater than 99.9% of all fuel rods in the core avoid transition boiling if the limit is not violated. Therefore, there is no increase in the probability of occurrence of a previously evaluated accident.

The fundamental sequences of accidents have not been altered. The Minimum Critical Power Ratio (MCPR) Operating Limits are selected such that potentially limiting accidents do not cause the MCPR to decrease below the ST MCPR anytime during the accident. Therefore, there is no impact on any of the limiting accidents. Therefore there is no increase in the consequences of any accident previously evaluated.

2. The proposed amendment will not create the possibility of a new or difTerent kind of accident from any accident previously evaluated.

The SLMCPR values are designed to ensure that fuel damage from transition boiling does not occur in at least 99.9% of the fuel rods as a result of the limiting postulated accident. The values are calculated in accordance with NRC-approved General Electric methods. The approved General Electric methods are comprehensive for ensuring that fuel designs will perform within acceptable bounds. The SLMCPR ensures that the fuel is protected in accordance with the design basis. The function, location, operation, and handling of the fuel remain unchanged. Therefore, the possibility of a new or different kind of accident is not created.

3. The proposed amendment will not involve a significant reduction in a margin of safety.

The SLMCPR values do not alter the design or function of any plant system. The new values were calculated using NRC-approved methods to maintain the same margin of l safety as presently exists for the prevention of transition boiling. At least 99.9% of the j fuel rods will avoid transition boiling if the SLMCPR is not violated. Therefore, a significant reduction in a margin of safety is not involved.

Based upon the above, we have determined that the proposed amendment " ,d not involve i a significant hazards consideration.

t1

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. TSCR-021 Attachment I to NG-99-0678 Page 4 of 4 I-Local Public Document Room Location: Cedar Rapids Public Library,500 First Street '

l SE, Cedar Rapids, Iowa 52401 Attorney for Licensee: Al Gutterman; Morgan, Lewis & Bockius,1800 M Street NW, Washington, D.C. 20036-5869 i

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