ML20112B015

Forwards Request for Schedular Exemptions for Mods to Meet Requirements of 10CFR50,App R.Schedular Exemption Necessary Due to Expanded Scope of Studies & Delays in Purchasing Approved Cable Wrapping Matl & Long Delivery Times

ML20112B015
Person / Time
Site:	Prairie Island
Issue date:	12/21/1984
From:	Musolf D NORTHERN STATES POWER CO.
To:	Office of Nuclear Reactor Regulation
References
TAC-56779, TAC-56780, NUDOCS 8501100183
Download: ML20112B015 (6)

Text

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e Northern States Power Company 414 Nicollet Mall Minneapolis. Minnesota 55401 December 21, 1984 Telephone (612) 330-5500 Director Office of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Schedular Exemption Request for Modifications to Meet the Requirements of Appendix R to 10 CFR 50

Reference:

(a) Letter from D M Musolf to Director of NRR dated January 23, 1984 " Exemption Request to the Requirements of Appendix R to 10 CFR 50" (b) Letter from D M Musolf to Director of NRR dated April 5, 1984 "Information in Support of Exemption Requests dated January 23, 1984 and Request for Exemption from the Require-ments of Section III.0 of Appendix R to 10 CFR 50" (c) Letter from D G Eisenhut to D M Musolf dated April 26, 1984

" Exemption Request of January 23, 1984 - Fire Protection Schedular Requirements of 10 CFR 50.48(c) - Prairie Island Nuclear Generating Plant, Units 1 and 2" Attached for your review and approval are 40 copies of a request for schedular exemption for modifications required to meet Appendix R to 10 CFR 50.

This schedular exemption is necessary due to an expanded scope of studies detailed in Attachment 2 to Reference (a) and difficulties encountered while performing them. Delays were also encountered in purchasing approved cable wrapping material and with longer delivery times than originally planned.

Please contact us if you have any questions or if additional information is necessary.

David Musolf Manager-Nuclear Support Services DMM/ TAP / dab c: Secretary ofitha'Commissicn;(orig + 2 copies)

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Regional Administrator-III , NRC NRR Project Manager, NRC Resident Inspector, NRC G Charnoff 1

Enclosures 650110018:1 841221 I I PDR ADOCK 05000282 (

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I UNITED STATES NUCLEAR REGULATORY COMMISSION NORTHERN STATES POWER COMPANY PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket No. 50-282 50-306 LETTER DATED DECEMBER 21, 1984 SCHEDULAR EXEMPTION REQUEST FOR MODIFICATIONS TO MEET THE REQUIREMENTS OF APPENDIX R TO 10 CFR 50 Northern States Power Company, a Minnesota corporation, by this letter dated December 21, 1984 hereby submits a request for exemption from the requirements of 10 CFR Part 50, Section 50.48 (c).

This letter contains no restricted or other defense information.

NORTHERN STATES POWER COMPANY By David Musolf Manager - Nuclear Support Service On this $d- day of hz,w , A / , /9f M before me a notary public in and for said County, personally appeared David Musolf, Manager - Nuclear Support Services, and being first duly sworn acknowledged that he is authorized to execute this document on behalf of Northern States Power Company, that he knows the contents thereof and that to the best of his knowledge, information and belief, the statements made in it are true and that it is not interposed for delay.

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I DODY A. SkOSE I NOTARY PUBLIC = WNNESoTA l '

HENNEPIN COUNTY My Comrmssion Espues Cec. 26,1989 :

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- c Attachment 1 EXEMPTION REQUEST FIRE' PROTECTION RULE SCHEDULAR REQUIREMENTS I. EXEMPTION REQUEST Per the provisions of 10 CFR 50.12, Northern States Power requests-exemption from the schedular requirements of 10 CFR 50.48 paragraph C as amended by Reference (c) of -this letter. The modification for which schedule relief is requested is the cable wrapping for both units 1 and 2.

II. . BASIS FOR EXEMPTION REQUEST s Under our technical exemption requests addressing fire areas 31, 32, ;58, 59, 73 and .74, Northern States Power committed to wrapping portions of cable trays in an approved.one hour fire barrier. The technical exemption requests were subsequently reviewed and approved by the.HRC. Staff. The tolling period under-10 CFR _  ;

50.48(c)(6) was' ended on May 4,1983, requiring . completion of the .

cable wrapping by February 4, 1984. A. schedular exemption request was granted on April 26, 1984 which extended the required completion-

'date until December 31, 1984.

Reference (a), provided the Staff with the basis for extending the

~ schedule from February 4, 1984 until December 31, 1984. In it

. studies were detailed to resolve,two safety issues associated with the wrapping. The results of the cable derating study indicated that the loading of power cables in ladders when wrapped would exceed . the derated' capacity of the' cables. - This resulted in two additional studies being initiated. One,- to! identify v.odifica-tions to power cables in ladders, that would provide sufficient derated capacity to allow wrapping'and-one.to-review the effect of the wrapping of power cab 1es in conduit. 'The power cables required for the Appendix R safe shutdown equipment were then reviewed. "

against the results of.these studies and modifications were determined. In-many. cases it was determined that the cables ,

requiring wrapping under the requirements of. Appendix R were a

'small percentage of the. total inventory .of cables' contained in a ladder. To preclude having to remove the wrap in the future when

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other modifications are done it was found to be more practical to reroute those cables required under Appendix R separately .in conduit and then wrap them. This greatly; expanded the number of cables to be -reuted in conduit. For those cables which~

which were rerouted in conduit an additional complication occurred. To facilitate future modifications in which new cable associated with Appendix R might be necessary, 5-inch conduit was

-installed'to allow for room to install them. 'It was determined

that our field standard for support design and installation only. included supports up through 4-inch conduit. This made it necessary to upgrade the field standard to include conduit supports

.for conduit up to 5 inches in diameter. The net result of the delays

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, 3; encountered in accomplishing the above activities being that all of the cables have .now been rerouted (Unit I during the Winter, 1983/84 refueling outage and Unit 2,duriug the Fall, 1984 refueling outage) and the supporting derating studies completed on December 12, 1984.

The_ modification packagestfor the wrapping of lche conduits are now being processed.- /

-Resolution of the 'other safety issue involved a review of the <cible tray and. ladder mechanical support system,due to the additional

. weight'of the wrapping. DuringJt he course of the study on the. '

supports a concern was raised over how full the actual trays and ladders were becoming and tu capacity not.only of the supports but the trays and ladders to support both the cables and the wrapping material. As a result, allferays and ladders have been reviewed

' giving rise to a large number of modifications to assure adequate support. The formal report ,is to be issued the week of Dece,aber 24,

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There have also been' delays experienced because of^the intterface

-between Environmental Qualification work going on at the 'smae time Appendix R work was being planned. In fire areas 31 and 32 the potential for relocating the turbine driven auxiliary feedwater pumps, because of enviroasental' qualifications considerations, would have eliminated the need to' wrap the redundant train because adequate- separation would have been provided to meet (Appendix R <

requirements. A study was initiated and was completed this month to review moving those pumps. It was concluded that it.was not ,

necessary or practical to move thse so.the need for wras ing 7 still exists. . Planning for , wrapping of ~ cables in this ar'ea r (s#

continued But the finalwhile reviewing decision the possibility.of to wrap was ultimately moving the ' pumps.f' ,

delayed. , (

g .g Finally, during the procurement of the wrapping material fNoe TSI Ltwo problems have' delayed delivery of the material. First, i following initiation of the purchase requisition, difficulties were encountered in negotiating the terms of the-contract.. This resulted in substantial delay in thf akarding of the contract.

The delay in- the award of the coatract led to a t.eemd problem. ,

Lead times of 30 to 40 days quoterduring -the , time of initial  ;

planning and discussions become 60 to 30 days! oy the tica the.

contract.was awarded. This-was due'to the large influx of orders which the manufacturer received when, at theWC redoAal -

J workshops, it was ;1 earned that TSI's material'was ok whf.:h ;

they.had approved for use as a one-hour barrier.

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. This delay in material. delivery now has the material' arriving j6st

'before the Unit-1 refueling outage. This results fin' the manpower for. installation of the wrap not being available unt'll at leas't March = 1, ~ 1985 which is the current schedule for , outage completion.

As those individuals complete their outage related work, they will begin-installation of the one hour' wraps. It is astimated that the installation work will take besc/een'60 and 90 days. Scheduled completion of all cable wrapping is now June 1, 1985. <

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SUMMARY

EVALUATION In summary, Northern States Power has made an extensive effort to comply with the rules of-Appendix R. As often occurs at operating plants, evaluation of potential safety issues involving modifications has impacted the schedule for Appendix R work. Evaluation .of these issues' and their satisfactory resolution -

resulted-in more time being needed than-was anticipated. Therefore, extension of the completion date for wrapping of cables is requested to June 1, 1985.

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CORRESPONDENCE C0hTT0L TICKET David Musolf

" H'JM3kR: . SECY 85-2 LOGGING DATE: 1/4/85 0FFICE OF THE SE;RGARY Dd ACTIO:: OFFICE: ED0 AUTHOR: David Musolf AFFILIATION: Northern States Power Company Lt.: .R DATE: 12/21/84 FILE CODE:

ADDRESSEE:

cct'. Chilk Schedular exemption req for modifications to meet the SUWECT** requirements of Appendix R to 10 CFR 50 ACTION: . Appropriata DISTP.IBUTION:

SPECIAL HANDLING: None SIGNATURE DATE: FOR THE C0riilSSION:

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