ML20101Q713

Revised Application for Amend to License DPR-49,rewording Request for Consistency w/NUREG-1433,rev 1

ML20101Q713
Person / Time
Site:	Duane Arnold
Issue date:	04/09/1996
From:	Franz J IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Russell W NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20101Q717	List: ML20101Q719 NG-96-0299, Revised Application for Amend to License DPR-49,rewording Request for Consistency w/NUREG-1433,rev 1
References
RTR-NUREG-1433 NG-96-0299, NG-96-299, NUDOCS 9604150149
Download: ML20101Q713 (8)

Text

IES Utilities Inc.

200 First Street S E.

PO. Box 351 Cedar Rapkis, IA 52406-0351 Telephone 319 398 8162 g

Fax 319 398 8192 UTILITIES ,,,,,,, ,,

Mce President, Nuclear April 9,1996 NG-96-0299 Mr. William T. Russell, Director OfGee of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station PI-37 Washington, DC 20555-0001

Subject:

Duane Arnold Energy Center Docket No: 50-331 Op. License No: DPR-49 Request for Technical SpeciGcation Change RTS-286A,(EOC)RPT Operability and Surveillance Requirements

Reference:

RTS-286, dated November 15,1995, NG-95-2969 File: A-117

Dear Mr. Russell:

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

This 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 Hazards Consideration, is being forwarded to our appointed state official pursuant to 10 CFR Section 50.91.

In the referenced submittal, we requested revision to the DAEC TS in part, to clarify the Recirculation Pump Trip (RPT)" Minimum Operable Channels" requirement. During review of that request, the NRC suggested that the requirement be reworded to be consistent with the Improved Standard Technical Specifications, NUREG-1433, Revision 1. The suggestions have been incorporated and are being submitted as Revision A to RTS-286 (RTS-286A).

This letter transmits RTS-286A, which consists of RTS-286 wbh revisions indicated by revision bars in the margin. The Environmental Consideration is not affected, but is included for completeness.

In this letter, we commit to specifying an operating limit Minimum Critical Power Ratio (MCPR) penalty in the cycle-specific Core Operating Limits Report (COLR).

A 96b4150149 960409 PDR ADOCK 05000331 [ i p PDR m

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An , S Industnes Company i

t Mr. William T. Russell NG-96 0299 .

April 9,1496 Page 2 Should you have any questions regarding this matter, please contact this office.

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

IES UTILITIES INC.

By .

s hn F. Frahz - I

[Vice President, Nuclear State ofIowa (County) of Linn Signed and sworn to before me on this 7 Y ayd of ___ /)##/ L. ,1996, by TOHO 4' f'/% p .

AhiYb/f YL M00 Notfiry Public in and for thef tate oflof A1A/'/W 89 /999 Commission Expires Attachments: 1) Evaluation of Change Pursuant to 10 CFR Section 50.92

2) Proposed Change RTS-286A to the Duane Arnold Eenergy Center Technical Specifications

3) Environmental Consideration

4) Safety Assessment JFF/LBS N \lowa\Licensih3Vts\rts.286A. doc cc: L. B. Swenzinski L. Liu G. Kelly (NRC-NRR)

H. Miller (Region III)

S. Brown (State ofIowa)

NRC Resident Office Docu

. RTS 286A Attachment I to

, NG-96-0299 Page1of4 EVALUATION OF CHANGE PURSUANT TO 10 CFR SECTION 50.92

Background:

The End of Cycle Recirculation Pump Trip ((EOC)RPT) system was installed at the Duane Arnold Energy Center (DAEC) in 1980 to increase the margin to the reactor fuel safety limit for Minimum Critical Power Ratio (MCPR) during the transients involving turbine trips at the end of an OPERATING CYCLE while at reactor power greater than or equal to 30%. The system consists of instruments arranged in two trains oflogic which monitor the position of Turbine Stop Valves and Turbine Control Valves. Upon Turbine Stop Valve closure and/or Turbine Control Valve fast L

closure, the reactor recirculation pump motor-generator set output circuit breakers open to trip the .

pumps. Tripping the recirculation pumps reduces the core now and thereby adds negative reactivity which counteracts the positive reactivity added by the pressurization associated with a turbine trip.  ;

,The existing Technical Speci6 cations (TS) require that reactor power be reduced to below 85% in the event that the (EOC)RPT system is not OPERABLE. The intent is to maintain an adequate margin to the safety limit (SL) MCPR. Ilowever, with current fuel designs, this margin can be readily met with little or no reduction in reactor power. This proposed amendment would impose an .

operating limit (OL) .MCPR penalty on continued plant operation to maintain that necessary margin to the SLMCPR as an alternative to requiring a power reduction.

Additionally, there may be entire OPERATING CYCLES during which the (EOC)RPT would not be required because of sufGcient margin to the OLMCPR. Consequently, IES will have the option to ,

operate the DAEC with the (EOC)RPT in bypass and accept the resulting OLMCPR penalty in order to minimize the potential for spurious trips of the recirculation pumps and unnecessary surveillances of the (EOC)RPT which require that plant operating power be reduced.

During development of this TS change request, it was determined that the " Minimum Operable Channels Per Trip System" and the " Response Time" acceptance criteria should be input specific in order to ensure that the (EOC)RPT performs as designed.

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

Duane Arnold Energy Center. Linn County. Iowa l Date of Amendment Reauest: April 9,1996 Descriotion of Amendment Reauest:

The proposed TS amendment would revise the " Applicable Operating Mode" to recognize that the ,

(EOC)RPT is bypassed below 30% rated thermal power. It would revise the " Minimum Operable Channels per Trip System" to recognize that there is a need to maintain two channels of each type of c input (Turbine Stop Valve closure and Turbine Control Valve fast closure) in order to satisfy the TS.

, - It would revise the Action Statement to require implementation of an OLMCPR penalty for continued operation without the (EOC)RPT. That OLMCPR penalty would be OPERATING CYCLE-specific and derived from the difference in MCPR calculated for the turbine trip events with (EOC)RPT in service and out of service. That penalty would be included in the DAEC cycle-specific CORE OPERATING LIMITS REPORT (COLR). The proposed amendment would also i

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l RTS 286A Attachment I to 7

NG-96-0299 Page 2 of 4 i

L l revise the Surveillance Requirements to increase the surveillance interval for the logic from monthly

to quarterly and allowed outage time (AOT) from two hours to six hours to be consistent with the a improved Standard TS, NUREG 1433, Revision 1. The proposed amendment would revise the

response time acceptance criteria based on recent reviews of the assumptions and the testing

methodology. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LIMITING CONDITION FOR OPERATION and subsequent 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to implement the OLMCPR penalty remain unchanged from the current time limits for (EOC)RPT logic out of service and time to reduce power, respectively.

Basis for Pronosed No Significant Hmrds Consideration:

4 i 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 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 i

from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

Aller reviewing this proposed amendment, we have concluded:

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l) The proposed TS amendment will not significantly increase the probability or consequences of 1

any previously evaluated accidents. The (EOC)RPT system was installed to preclude violation of reactor fuel limits, and the system will be preserved for that purpose. In the event that system is not available, an operating penalty will be imposed on the MCPR limit to assure sufficient margin to the limit to preclude fuel damage during the postulated turbine trip events.

[ Two (EOC)RPT trip functions will appear in TS Table 3.2-G: the Turbine Stop Valve Closure trip

function and the Turbine Control Valve Fast Closure trip function. This change will clarify the

requirement that two Turbine Stop Valve Closure channels and two Turbine Control Valve Fast l Closure channels are required for each Trip System. This will make the nomenclature of the

(EOC)RPT analogous to the (ATWS) RPT/ARI nomenclature and is consistent with the Improved Standard Technical Specifications, NUREG-1433, Revision 1. This will also assure that all inputs monitoring Turbine Stop Valve Closure and Turbine Control Valve Fast Closure will be available to initiate (EOC)RPT.

The change to the " Applicable Operating Mode" is an editorial change which reflects the existing j hardware bypass.

The change to Action 81 in TS Table 3.2-G will assure that when the (EOC)RPT system does not j meet the minimum TS availability requirements, the SLMCPR will not be challenged. By imposing a OLMCPR penalty for continued operation, the fuel thermal limits will not be challenged, since the  !

(EOC)RPT system was installed to accomplish the same goal. No increase in the consequences of the turbine trip events will result from this change. The OLMCPR penalty is dependent on cycle-specific parameters and will therefore be included in the cycle-specific COLR.

l The change to the surveillance interval results in (EOC)RPT logic channel functional tests being performed once per quarter instead of once per month. The change also revises the allowed out-of-i l

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i RTS-286A Attachment I to -

). ,

, NG-96-0299 Page 3 of 4 1

service time (AOT) for testing from two hours to six hours. These changes are consistent with the

improved Standard Technical Specifications, NUREG-1433, Revision 1. The (EOC)RPT is initiated

by instruments common to the Reactor Protection System (RPS)(i.e., turbine stop valve closure and j turbine control valve fast closure). The surveillance interval and AOT changes for these instruments

were evaluated in " Technical Specification Improvement Analysis for BWR Reactor Protection l System," NEDC-30851P-A, March 1988, for the RPS function. Although the (EOC)RPT functions l were not explicitly identified in that document, these changes can be considered bounded by that l analysis. The basis for this conclusion is similar to the basis established for the control rod block j instrumentation common to the RPS, as documented in " Technical Specification improvement i Analysis for BWR Control Rod Block Instrumentation," NEDC-30851 P-A, Supplement 1, October j 1988. Failure of the (EOC)RPT function could potentially lead to exceeding the SLMCPR, similar ,

} to the consequences of an unmitigated rod withdrawal error. The slight increase in risk of a j SLMCPR violation due to extending (EOC)RPT surveillance interval and AOT is offset by the same l l - benefits associated with the similar approved surveillance interval and AOT for the RPS. _Both the j above referenced reports have been apr roved for application at the DAEC via TS Amendment 193, dated April 14,1993. NRC Safety Eva uation Report for Topical Report GENE-770-06-1, " Bases

, for Changes to Surveillance Test Intervals and Allowed Out-Of-Service Times for Selected Instrumentation Technical Specificationa" (dated August 10,1992) went on to compare the

unavailabilities of the RPS and (EOC)RPT ftmetions and concluded that the proposed AOT and

surveillance interval changes for (EOC)RPF were acceptable. The NRC Safety Evaluation Report i and Topical Report GENE-770-06-1 have been reviewed and found to be acceptable for application j at the DAEC.

1

[ The changes to the " Operating Modes for which Surveillance Required" are clarifications and will 4

result in a more efficient utilization of resources. By stating that the surveillance applies only when the (EOC)RPT system is OPERABLE, the surveillances will not be performed needlessly. During

! the early part of an OPERATING cycle, the (EOC)RPT is not required to mitigate a turbine trip, and

! therefore, may be bypassed. At the time when the (EOC)RPT is assumed to be OPERABLE l pursuant to the analysis, it will be'made OPERABLE unless accepting the penalty on the OLMCPR

is preferable. The result of the proposed change will still be that the (EOC)RPT is demonstrated l OPERABLE at any time when it is required.

The change to the acceptance criteria for response time testing reflects a recent review of the analytical assumptions and the testing methodology. The (EOC)RPT is assumed to interrupt power

to the recirculation pump motor within 175 milliseconds after initiation of either turbine stop valve closure or turbine control valve fast closure. The response time test only measures a portion of the complete trip (the rest was measured as part of start-up testing). The portion measured is dependent on which trip input is being tested. The turbine control valve closure is sensed by a pressure switch monitoring the hydraulic fluid controlling the valve and therefore has no delay between valve

motion and initiation of the (EOC)RPT logic. The turbine stop valve closure is sensed by position switch. Since this switch is set to initiate (EOC)RPT at 10% valve closed, there is a brief delay

between the beginning of valve motion and initiation of the (EOC)RPT logic. The respective F proposed response time tests account for these differences, as described in the footnotes on TS page 3.2-36, and demonstrate that the measured portions of the action are within the allowed time periods.

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, RTS-286A Attachment I to l , . NG-96-0299 a

Page 4 of 4

None of the proposed changes will signincantly increase the probability of any accident previously j evaluated because the (EOC)RP r is not an initiator of any of those events. None of the proposed

- changes will signincantly increase the consequences of an accident because the (EOC)RPT system serves to prevent a turbine trip event from exceeding the fuel SLMCPR, and it will continue to perform in that capacity at any time when it is required to assure margin to the SLMCPR.

2) The proposed changes will not add a new or different kind of accident because the plant will not .

be operated in a different way. By allowing the implementation of a penalty on OLMCPR in lieu of

! reducing reactor power, the risk of a plant transient is reduced. Similarly, the surveillance interval

] and AOT extensions will also result in fewer plant power reductions for testing.

l The (EOC)RPT initiates a trip of the recirculation pumps and any TS change alTecting that system ,

i cannot result in an effect on any system other than those pumps. Consequently, no new accidents are j' postulated as a result of this proposed change.

1 . 3) The proposed change will not result in a signincant reduction in any margin of safety. The

[ (EOC)RPT performs to assure adequate margin to the SLMCPR. The proposed change will preserve i that function and require that additional margin to the SLMCPR be imposed for those times when I

the (EOC)RPT is not OPERABLE. The other changes are proposed because they assure correct .

(EOC)RPT function (inputs and response times).

4 Based upon the above, we have determined that the proposed amendment will not involve a

! signincant hazards consideration.

Local Public Document Room Location

Cedar Rapids Public Library,500 First Street SE, Cedar '

l. Rapids, Iowa 52401 i

Attornev for I icensee: Jack Newman, Kathleen H. Shea; Morgan, Lewis & Bockius,1800 M Street

] NW, Washington, D.C. 20036-5869 1

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RTS-286A Attachrnent 2 to

- - NG-96-0299 Page 1 of 2 1,

l PROPOSED CHANGE RTS-286A TO THE DUANE ARNOLD ENERGY CENTER TECHNICAL SPECIFICATIONS i J

The holders oflicense DPR-49 for the Duane Arnold Energy Center propose to amend Appendix A 4

(Technical Specifications) to said license by deleting certain current pages and replacing them with the attached, new pages. The List of Affected Pages is given below.

LIST OF AFFECTED PAGES

, l 3.2-34*

3.2-35 3.2-36 1

l 3.2-47* ,

, l

• Previously submitted as RTS-286, not affected by RTS-286A. .

EUMMARY OF CHANGES:

3 The following list of proposed changes is in the order that the changes appear in the Technical Specifications (TS).

hgt Descrintion of Chances 3.2-34 Editorial clarification in paragraph 3.2.G.1, "(EOC)-RPT."

3.2.-35 - Note (a) only applies to the (ATWS) RN/ARI Logic, move note (a) from the " Minimum Operable Channels Per Trip System" header to (ATWS) RN/ARI Logic.

- Due to table improvements, note (d) is no longer required and is deleted.

- Rename notes (e) and (f) as (d) and (e) respectively.

- Add note (e)(previously note (f)) to specify Applicable Operating Mode for "(EOC)RPT Logic".

- Add new note (e) (previously note (f)) to clarify that (EOC)RPT OPERABILITY requirement is dependent on reactor power.

- Break (EOC)RN Logic into two lines: Turbine Stop Valve Closure and Turbine Control Valve Fast Closure, add notes (b) and (c) to these two lines.

- Revise note (d) (previously note (e)) to increase (EOC)RPT AOT from two hours to six hours and to be consistent with Improved Standard Technical Specifications, NUREG-1433, Revision 1.

- Revise " Action 81" to require that when (EOC) RN is not 4 OPERABLE, operating limit MCPR penalty is to be applied.

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RTS 286A .Attshment 2 to

. NG-96-0299 l Page 2 of 2 i

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! 3.2-36 Change "(EOC) RFr Logic" " Channel Functional Test" frequency j from monthly to quarterly. Clarify " Operating Modes for Which Surveillance Required" for "(EOC) RFr Logic" and "RPT Breaker" by adding notes "***" and "#," respectively. Revise " Response Time" test acceptance criteria to specify appropriate values for the two (EOC) RPT inputs and clarify the method of measuring that response time.

l Add note "##" to reference RFT Surveillance Requirements.

3.2-47 Revise Bases to reflect above changes.

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