NG-94-2451, Application for Amend to License DPR-49,modifying Surveillance Testing of ESW Sys by Deleting Flow Rate Test & Requirement to Test Pumps Each Week When River Water Temp Exceeds 80 F

Application for Amend to License DPR-49,modifying Surveillance Testing of ESW Sys by Deleting Flow Rate Test & Requirement to Test Pumps Each Week When River Water Temp Exceeds 80 F

ML20070E022
Person / Time
Site:	Duane Arnold
Issue date:	06/30/1994
From:	Franz J IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Russell W NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
Shared Package
ML20070E023	List: ML20070E025 NG-94-2451, Application for Amend to License DPR-49,modifying Surveillance Testing of ESW Sys by Deleting Flow Rate Test & Requirement to Test Pumps Each Week When River Water Temp Exceeds 80 F
References
NG-94-2451, NUDOCS 9407140008
Download: ML20070E022 (6)

Text

.. _. .

I,HJ .

UTILITIES INC.

John F. Franz, Jr.

Vice President Nuclear June 30, 1994 NG-94-2451 Mr. William T. Russell, Director Office of Nuclear Reactor Regulation  ;

U. S. Nuclear Regulatory Commission '

Attn: Document Control Desk Mail Station P1-137  :

Washington, DC 20555

Subject:

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

Request for Technical Specification Change (RTS-240A): " Revision of ESW Flow Requirement 4.8.E.1" i

Reference:

1) Letter, Mineck (IELP) to Murley (NRC), RTS-240, dated 6-28-91, ,

NG-91-1366

2) Letter, Shiraki (NRC) to Liu (IELP), dated 9-29-92 File: A-117, E-13 4 i

Dear Mr. Russell:

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 (TS) for the Duane Arnold Energy Center (DAEC).

The proposed change will modify the surveillance testing of the '

Emergency Service Water'(ESW) system by deleting the flow rate test and the requirement to test the pumps each week when river water teroperature exceeds 80 F and by adding a Surveillance for the Cedar River water temperature (Ultimate Heat Sink). The >

curve whice was used previously to determine the minimum acceptable 110w rate will be removed from the DAEC TS. A ,

calculation recently performed on the ESW system revealed that the individual component flow requirements previously listed in the DAEC Final Safety Analysis Report (FSAR) Table 9.2-1, which '

formed the basis for the current TS requirement, were overly conservative. FSAR Table 9.2-1 has been revised to reflect the newly calculated flow requirements.

This change request had been submitted previously (Reference.1) and NRC review resulted in several comments (Reference 2). The change request has been revised to alleviate those comments.

Attachment-5 to this letter contains descriptions of our -

disposition of each comment.

9407140008 940630 / I 150010- ;Da aDockosooogg2 #SI ,

l General Office

• P.O. Box 351

• Cedar Rapids, Iowa 52406

• 319/398-4411 '\

An IES INDUSTRIES Company. j J

Mr. William T. Russell Jun'e 30, 1994 NG-94-2451 Page 2 l

This application has been reviewed by the DAEC Operations Committee and the DAEC Safety Committee. Pursuant to the requirements of 10 CFR 50.91, a copy of this submittal, including  :

the no significant hazards considerations analysis, is being I forwarded to our appointed state official.

We hereby requast that this amendment be made effective 120 days after issuapre to allow adequate time for implementation.

No new commitments are made by this letter.

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

IES Utilities Inc.

By

~

John F. Frant M

/VicePresident, Nuclear i State of Iowa l (County) of Linn

/]

Signed and sworn to before me on tnis b day of lA L ,

f 1994, by d Ohn -b b6'(t l% /)// / -

q

/RK lad /

Notary Publ c in and for the State of Iowa J

MARY MICHELE O'NEAL MY COMMIS$10h L,- v aqEJ,MRES f r q l l l8U I

/

Commis{losExpired l JFF/SRC/pjv~

Attachments: 1. Evaluation of Change with Respect to 10 CFR 50.92

2. Proposed Change (RTS-240A) to the Duane Arnold l Energy Center Technical Specifications

3. Safety Assessment

4. Environmental Consideration

5. IES Utilities Review of Technical Evaluation of DAEC ESW Technical Specification Change Request cc: S. Catron L. Liu L. Root S. Brown (State of Iowa)

R. Pulsifer (NRC-NRR)

J. Martin (Region III)

NRC Resident Office DCRC I

m

RTS-240A Attachment 1 to NG-94-2451 Page 1 of 4 EVALUATION OF CHANGE WITH RESPECT TO 10 CFR 50.92

Background:

The Emergency Service Water (ESW) system provides a reliable source of cooling water to essential safeguards equipment under a loss-of-offsite power (LOOP) condition or after a loss-of-coolant accident (LOCA). The ESW system provides cooling water to the following components:

• Emergency Diesel Generator coolers Residual Heat Removal (RHR) and Core Spray pump room cooling units Reactor Core Isolation Cooling (RCIC) room cooling units High Pressure Coolant Injection (HPCI) room cooling units Control Building Chiller condensers

• RHR pump seal coolers Core Spray pump motor coolers Control Building HVAC instrument air compressors RHR Service Water pump motor coolers The ESW system consists of two independent trains, each supplied by one full capacity ESW pump rated at 1200 gpm. The capability of the ESW system to remove heat froni the aforementioned loads is a function of the system flow and inlet temperature (i.e. the Cedar River temperature). The maximum design inlet temperature of the ESW system is 95 F. At lower inlet temperatures, the flow required to remove a constant quantity of heat decreases proportionally. Presently, the DAEC Technical Specifications (TS) require that the total flow rate of the ESW system meet or exceed the required flow rate shown in TS Figure 4.8.E-1 for a specified river water temperature. Figure 4.8.E-1 was developed by calculating the ESW system flow rate.e required to provide adequate component cooling at river water tempera tures of 80 F, 85 F, 90 F and 95 F, and was incorporated irto the TS by Amendment 10 to our Operating License in 1975. Amendment 10 also incorporated the requirement to perform surveillance testing of the ESW pumps each week when river water temperature exceeds 80 F. At elevated river water temperatures, the ESW flow rates required by TS Figure 4.8.E-1 approached the design flow rate limitatione of the pumps. The weekly surveillance provided additional assurance that the required flow rates would be achieved under those conditions.

I

RTS-240A Attachment 1 to NG-94-2451 Page 2 of 4 During the Service Water Safety System Functional Inspection (IR 50- ,

331/90003) performed at the DAEC in 1990, it was noted that the l calculations for the flow rate requirements which formed the basis of I the ESW surveillance and TS Figure 4.8.E-1 could not be retrieved. In response to this concern, a comprehensive re-evaluation of the maximum individual design heat loads was performed. The analysis was performed using a fouling factor of 0.001 for heat exchangers cooled by ESW. This value is typical for river water systems as specified in TEMA (Tubular Exchanger Manufacturer Association) tables. Also included in the analysis is an adjustment for thermal stratification in the rooms of concern. The results of the analysis indicate that a minimum ESW flow rate of 756 gpm is required for a river water inlet temperature of 95 F. (Individual branch flows are listed in FSAR Table 9.2-1.) This value is substantially less than the current TS requirement of 1129 gpm at a river water inlet temperature of 95 F (Figure 4.8.E-1). This reduction in the required flow rate results from the improved modeling methodology, current design information, and the reduction of room heat loads through the installation of additional insulation on piping or components.

The proposed amendment will revise ESW surveillance requirements and delete Figure 4.8.E-1 from the TS. As a result of the ESW flow analysis, the previous concerns of the required pump flow rates approaching the design pump flow rates at elevated river water temperatures have been eliminated. Consequently, the requirement for testing the pumps weekly when river water temperature exceeds 80 F is no longer warranted and has been deleted. The quarterly testing of each pump is still required, but is specjfled in accordance with the DAEC Inservice Testing (IST) Program. Removal of the requirement to operate the ESW pumps each week will eliminate unnecessary operation and testing of the ESW pumps.

A new surveillance is proposed to monitor river water temperature.

This surveillance will demonstrate ESW compliance to the aforementioned calculations and is based on temperature trends.

IES Utilities Inc., Docket No. 50-331, Duane Arnold Energy Center, Linn County, Iowa Date of Amendment Request: June 30, 1994 Description of Amendment Request:

The proposed License Amendment would revise Section 4.8.E.1.c of the DAEC TS to reflect the revised ESW system surveillance requirements.

1 Specifically, the proposed change: l

1. Deletes Figure 4.8.E-1, "DAEC Emergency Service Water Flow Requirement" and associated references to this figure in the List 4

RTS-240A Attachment 1 to NG-94-2451 Page 3 of 4  ;

of Figures and in Section 4.8.E.1.c.

2. Revises Section 4.8.E.1.b to specify that ESW pump and motor surveillance be performed in accordance with the DAEC IST Program.

3. Adds surveillances for river water temperature.

4. Deletes reference to 4.5.G.1 from 4.8.E.2. l l

S. Revises the bases to add information on surveillance l requirements.

These changes are consistent with the Draft Improved Technical Specifications for BWR/4 plants.

Basis for proposed no significant hazards consideration: l The Commission has provided standards (10 CFR 5'.92(c))

0 for 1 determining whether a significant hazards consideration exists. A proposed amendment to an operating license for a facility involves no 1 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.

. In reviewing this proposed request for Technical Specification change, we have reached these conclusions:

1) The proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated. No physical changes will result from this amendment.

l The ESW system will still maintain its ability to support various  :

safety related equipment which is designed to mitigate the consequences of certain accidents and transients. These safety related systems play no part in the probability of these accidents or transients occurring. Since the ESW system will continue to fully support the cooling requirements of the safety related equipment which mitigate the. consequences of certain accidents and transients, this amendment will not affect.the consequences of these accidents and transients. The re-analysis of the component heat loads assumed worst-case conditions and involved conservative assumptions. Our continuing program for monitoring heat _ exchanger performance, which was established in response to Generic Letter 89-13, " Service Water System Problems Affecting Safety-Related Egtipment," will continue to verify _that the individual components are capable of performing their design y function. Therefore, the proposed amendment does not involve a

1 i

l RTS-240A Attachment 1 to NG-94-2451 l Page 4 of 4 change in the probability or consequences of an accident previously evaluated.

2. The proposed license amendment does not create the possibility of a new or different kind of accident from any previously evaluated. The safety function of the ESW system is unchanged.

The revised flow requirements for the system have been established using conservative assumptions and worst case heat loads and are appropriately documented in the FSAR and plant procedures. This amendment will result in no physical changes to the ESW system and therefore, will not affect its ability to continue to provide reliable cooling water. Consequently, the proposed license amendment does not create the possibility of a new or different kind of accident from any previously evaluated.

3. The proposed amendment will not reduce the margin of safety. The re-analysis of the ESW flow rate requirements and component heat loads was performed using conservative assumptions and maximum component heat loads. The actual operation of the ESW system will not be changed. Any degradation of ESW pump performance would be detected by the IST program which requires quarterly testing of these pumps and monitoring of the pump's differential pressure and flow. Deleting the requirement to perform the surveillance each week when river water temperature exceeds 80 F will not reduce the margin of safety because even at a river water temperature of 95 F, the required ESW flow to supply all the branches is well below the normal system flow rate of approximately 1100 gpm. Deleting the weekly surveillance will eliminate unnecessary testing of the ESW pumps, thereby reducing wear on the pumps. Adding a surveillance requirement for river water temperature will formalize the recording of water temperature every hour to assure acceptable ESW performance.

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

Local Public Document Room Location: Cedar Rapids Public Library, 500 First Street SE, Cedar Rapids, Iowa 52401 Attorney for Licensee: Jack Newman, Kathleen H. Shea, Newman, Bouknight & Edgar, P.C., 1615 L. Strac' NW, Washington, D.C.

20036-5610 l

l l

l