NG-97-1578, Application for Amend 195 to License DPR-49,supplementing thermal-hydraulic Analysis Included as License Rept in

Application for Amend 195 to License DPR-49,supplementing thermal-hydraulic Analysis Included as License Rept in

ML20211J224
Person / Time
Site:	Duane Arnold
Issue date:	10/03/1997
From:	Franz J IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Collins S NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20211J229	List: ML20211J233 ML20211J237 NG-97-1578, Application for Amend 195 to License DPR-49,supplementing thermal-hydraulic Analysis Included as License Rept in
References
NG-97-1578, NUDOCS 9710080038
Download: ML20211J224 (7)

Text

,,1 - t"'-

+

'I' il LI'$tt b [

l . :a w e r :n ,:s :A !L~ ?M

,,: n ms .

o. u m em UTILITIES w, r reanur.

; n w t.n.,e w October 3,1997 NO 971578 NL. Samuel J. Collins, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission l

Attn: Document Control Desk l

Mail Station PI 37 Washington, DC 20555 0001 l

Subject:

Duane Arnold Energy Center Docket No: 50 331 l Op. License No: DPR 49 l Request for Operating License Change (RTS 296): Refueling Operations l

Ref:rences: 1) Letter, Liu (lES) to Murley (NRC), dated March 26,1993, Spent and ,

New Fuel Storage l

2) Letter, Pulsifer (NRC) to Liu (lES), dated February 24,1994, Duane Arnold Energy Center License Amendment 195 File: A 117,J 80a

Dear Mr. Collins:

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

In Reference 1, IES Utilities Inc. submitted a request for an Operating License Amendment to rerack the DAEC fuel pool. This request was granted as Amendment 195 (Reference 2). The purpose of this Operating License Amendment request is to supplement the thermal hydraulic analysis included as a license report in Reference 1.

Specifically, this request proposes to allow start of core ofiload as soon as 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> after shutdown instead of the 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> currently specified in Reference 2.

The proposed Operating License change is described in Attachment 2. A licensing report Y containing our thermal hydraulic analysis is included as Attachment 5.

\ \

U

' ' ,' ' lill!!llll!l1,illl]l!llJ:lliIll 9710000030 971003 DR ADOCK0500g1 , g ., ,

1 Mr. Samuel J. Collins 0

No.971578 October 3.1997 Page 2

' i his application has been reviewed by the DAEC Operations Committee and the Safety Committee. A copy of this submittal, along with the evaluation of No Significant llazards Consideration, is being fonvarded to our appointed state ofilcial pursuant to 10 CFR Section 50.91.

The DAEC anticipates beginning fuel movement 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> aller shutdown during Refueling Outage 15, currently scheduled to begin April 2,1998. Therefore, we respectfully request review and approval of this Operating License Amendment by April i

2,1998. Should you have any questions regarding this matter, please contact this oflice.

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

IES UTILITIES INC.

By- A

/ohn F. Fran' z I Vice President, Nuclear l State orlowa l (County) of Linn r

Signed and swom to before me on this 3^ day of O e6 W ,1997, by hMd.dh .

6 U gt h. .. kM Notary Public in and for the State ofIowa h1 n 3 */ . /99 7 Co'mmission Expires Attachments; l) Evaluation of Change Pursuant to 10 CFR Section 50.92

2) Proposed Change (RTS 296] to the DAEC Operating License

3) Safety Assessment

4) Environmental Consideration

5) Thermal llydraulic Evaluation of the DAEC Spent Fuel Pool with RilR Intertie, prepared by Holtec International JFF/LBS i

7 g Mr. Samuel J. Collins NGo971578 October 3.1997 Page 3 cc: L. D. Swenzinski L. Root D. Wilson G. Kelly (NRC NRR)

A. B. Beach (Region 111)

S. Brown (State orlowa)

NRC Resident Ofrice Docu i

f

1 I Attachment i to NG.971578 Pagei EVAL.UATION OF CHANGE PURSUANT TO 10 CFR SECTION 50.92 1

Ilackcround:

IES Utilities Inc. submitted Reference 1 on March 26,1993 requesting an Operating License /fechnical Specification Amendment to allow rerack of the Duane Arnold Energy Center (DAEC) fuel pool, in support of that request, the DAEC performed a thermal-hydraulic analysis for four refueling scenarios or " cases". Case I simulated the Standard Review Plan (SRP) discharge condition labeled as the normal scenario with appropriate modification for 18 month operating cycles; Case 2 simulated the full core ofiload scenario of the SRP. The purpose of these cases was to demonstrate the compliance of the Fuel Pool Cooling and Cleanup (FPCCU) system with the SRP. These cases do not represent actual discharge scenarios at the DAEC. Case 3 represented a full core offload, starting 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> aller shutdown, following an 18 month cycle, using two trains of FPCCU to provide SFP cooling. Case 4 represented a full core ofiload using two trains of FPCCU, starting 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> after shutdown, following 36 days of power operation.

IES Utilities Inc.. Docket No. 50-331.

Duane Arnold Enerev Center. Linn County. Iown Date of Amendment Reauest: October 3,1997 Description of Amendment Reauest:

The purpose of this amendment request is to supplement the thermal hydraulic analysis submitted to the NRC as Reference 1. Specifically, this request introduces three new refueling scenarios which support beginning fuel movement as soon as 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> after shutdown instead of the 120 hour0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> decay time required by Amendment 195 (Reference 2).

These three new scenarios are identified as Cases A, B and C and are analyzed in Attachment 5.

Case A assumes a planned (i.e., follows 18 months of power operation) full core ofiload with one FPCCU train mnning before Residual lleat Removal Supplemental Fuel Pool Cooling (RilR-SFPC) it initiated. RIIR SFPC is assumed to be in service when SFP temperature reaches 120 F. RilR SFPC provides cooling to the Spent Fuel Pool (SFP) and reactor cavity by taking suction trom the Residual 11 eat Removal (RliR) Shutdown Cooling system piping and diverting a portion of flow to the SFP The transfer canal gates are open and water is able to flow from the SFP to the flooded reactor cavity. The s

analysis conservatively assumes FPCCU is secured when RilR SFPC is used.

Case B is identical to Case A except it assumes two FPCCU trains are running prior to initiation of RilR-SFPC.

Case C assumes an unplanned full core ofiload with two FPCCU trains running prior to initiation of RilR SFPC. RHR-SFPC is assumed to be in service when SFP temperature

T

8. Attachm:nt I to NO 971578 Page 2 reaches 120'F. This scenario consists of a normal 36 day refueling outage followed by 45 days of full power operation and a subsequent unplanned transfer of the entire core to the SFP. The analysis conservatively assumes the recently loaded fresh fuel has tmdergone 18 months of exposure even though it has been in the reactor for only 45 days.

The three cases analyzed in Attachment 5 evaluate the control and removal of decay heat generated by full core discharges. During a partial core discharge or "shuffic", the rate of heat transfer to the SFP as well as the total decay heat transferred to the SFP would be l less than that expected for a full core discharge, it is not anticipated, therefore, that initiati g RHR SFPC would be required for a core shume, llowever, RilR SFPC could be initiated ifit was determined that the FPCCU system was not adequately removing decay heat or if the FPCCU system was removed from service (e.g., maintenance). The l decay heat removal capacity of RilR SFPC is larger than that of the FPCCU system, and j would be more than adequate to remove the SFP heat generated during a core shume.

DAEC procedures require the use of FPCCU and/or RHR-SFPC to maintain SFP ,

temperatures below 150'F. For a fuel shume, the DAEC will control SFP temperatures using SFP heatup rates and decay heat generation curves to ensure RilR SFPC is initiated as needed to preclude SFP temperature from exceeding the maximum SFP temperature calculated for Case C of Attachment 5, i.e.,159'F. For a full core omond, DAEC l procedures will be changed to direct operators to ensure RilR-SFPC is in service prior to SFP temperature exceeding 120'F, thereby precluding SFP temperature from exceeding 159'F.

Basis for omnosed No Slenificant Hazards Consideration:

The Commission has provided standards (10 CFR Section 50.92(c)) for determining whether a significant hazards consideration exists. A proposed amendment to an operating license for a facility involves no significant hazards consideration if operation of the facility in mordance 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.

Attachment 5 calculates the maximum bulk SFP temperature reached, the maximum local water and fuel cladding temperatures achieved,-and the minimum time to take action following a loss of forced cooling with cask pit isolation gate failure event in order to prevent fuel in the SFP from being uncovered for Cases A, B and C. The loss of forced cooling event assumes a cask pit isolation gate failure occurs when the SFP bulk temperature is at the calculated maximum. The minimum time to take action following a loss of forced cooling with cask pit isolation gate failure event in order to prevent fuel in

r

! Anachm:nt I to NO 971578 l'a p )

the SFP from being uncovered is hereaner referred to as " minimum time to action". For clarity, only the bounding cases will be discussed below.

Aner reviewing this proposed arnendment, we have concluded:

1) The proposed chuge will allow initiation of core omond earlier after shutdown than is currently allowed. Attachment 5 shows that maximum bulk spent fuel pool (SFP),

local water, and fuel clad temperatures will remain within acceptable limits and, in fact, do not exceed those previously reviewed and approved for Amendment 195.

Attachment 5 shows the minimum time to action is calculated at 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> versus 5.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> previously reviewed and approved for Amendment 195. In the event of a loss of forced cooling with cask pit isolation gate failure event, the DAEC will use Emergency Service Water (ESW), a Seismic Category I system, to provide makeup to the SFP. It is l estimated to take no more than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to provide ESW makeup to the SFP, therefore the minimum time to action of 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> is sumcient time to prevent uncovering the fuel in

! the SFP.

l l The DAEC design basis refueling accident, as discussed in Section 15.10.2 of the Updated Final Safe 4y Analysis Report, assumes a twenty-four hour decay time before core omond bel ins. The proposed change does not adversely affect that accident analysis.

Therefore, the proposed change will not result in an increase in probability or consequences of at accident previously evaluated.

2) As shown in Attachment 5, the proposed change will not result in maximum bulk SFP, local water, or fuel clad temperatures which would initiate bulk pool boiling, challenge fuel rod integrity orjeopardize the structural integrity of the pool.

As stated above, the minimum tim: to action of 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> allows sumclent time to provide ESW makeup to the SFP.

Therefore, this change does not create the possibility of a new or different type of l

accident. '

3) This change will not result in maximum bulk SFP, local water, and fuel clad temperatures in excess of those previously evaluated and accepted per Amendment 195.

Case C of Attachment 5 does reduce the minimum time to action by one hour llowever, 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> does provide sumcient time to provide ESW makeup to the SFP. Furthermore, this change does not result in any change to the Technical Specifications. Therefore, this change does not result in a significant reduction in a margin of safety.

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

f 3 Attachment I to NO 971578 Page 4 Local Public Document Room I,ocation: Cedar Itapids Public Library,500 First Street SE, Cedar Itapids, Iowa $2401 Attorney for Licensee: Jack Newman, Al Outterman; Morgan, Lewis & Bocklus,1800 M Street NW, Washington, D.C. 20036 5869 l

l g