ML20128A524

Application for Amends to Licenses DPR-42 & DPR-60, Requesting Tech Spec Change to Authorize Use of Steam Generator Sleeves for Repair of Defective Steam Generator Tubes

ML20128A524
Person / Time
Site:	Prairie Island
Issue date:	05/17/1985
From:	Musolf D NORTHERN STATES POWER CO.
To:
Shared Package
ML20128A500	List: ML20128A494 ML20128A524 ML20128A605 ML20128N156 ML20128N197 ML20128N270
References
TAC-57847, TAC-57848, NUDOCS 8505240247
Download: ML20128A524 (5)

Text

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UNITED STATES NUCLEAR REGULATORY COMMISSION NORTHERN STATES POWER COMPANY PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket No. 50-282 50-306 REQUEST FOR AMENDMENT TO OPERATING LICENSE NOS. DPR-42 & DPR-60 License Amendment Request Dated May 17, 1985

' Northern States Power Company, a Minnesota corporation, requests authorization for changes to the Technical Specifications as shown on the attachments labeled Exhibit A and Exhibit B. Exhibit A describes the proposed changes along with reasons for the change. Exhibit B is a set of Technical Specification pages incorporating the proposed changes. Exhibita C, D, and E are reports supporting the requested changes.

This letter contains no restricted or other defense information.

NORTHERN STATES POWER COMPANY By M David Musolf Manager - Nuclear Support Serv s on this /7E/ day of Ma-u. -. , /9ff before me a notary public in and forsaidCounty,personallyappredDavidMusolf, Manager-NuclearSupportServices, 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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c EXRIBIT A Prairie Island. Nuclear Generating Plant License Amendment Request Dated May 17, 1985 Evaluation of Proposed Changes to the Technical Specifications Appendix A of

_ Operating Licenses DPR-42 and DPR-60 Pursuant to 10 CFR Part 50, Sections 50.59 and 50.90, the holders of Operating Licenses DPR-42 and DPR-60 hereby propose the following changes to Appendix A Technical Specifications:

1. Technical Specification 4.12 Steam Generator Tube Surveillance Proposed Channes

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Revise Technical Specification 4.12 to permit use of steam generator tube sleeving for repairs.~ The following specific changes are requested:

a. Revise the term " plugging limit" to " repair limit" and revise the definition of this term to allow either plugging or sleeving of tubes which may become unserviceable.

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b. Revise Specification 4.12.D.2 to permit either plugging or slesving of tubes

'c. Revise the reporting requirements to require reporting of tubes which are sleeved.

d. Revise the basis to include a discussion of sleeving repairs.

e. Revise Table TS.4.12. "Steen Generator Tube Inspection" to permit sleeving as well as plugging repairs.

Refer to Exhibit B, pages TS.4.12-2. TS.4.12-4, TS.4.12-5, TS.4.12-6, TS.4.12-7, and Table TS.4.12-1 for the proposed wording changes.

Reason for Channe These changes are being submitted to permit the use of stesa generator tube sleeving as an alternative to tube plugging. Sleeving is a safe

.and effective repair procedure which does not remove tubes from se rvice.

F l EIRIBIT A continued

' Northern States Power Company has reviewed a variety of tube sleeving designs. . Three' designs have been selected for potential use at Frairie Island. Reports which describe these sleeving designs and provide information to support their use are attached as follows:

Enhibit C - WCAF-10757, "Frairie Island Units 1 and 2 Steam Generator Sleeving Report (Mechanical Sleeves)", January, 1985.

Exhibit D - WCAF-10820. "Frairie Island Units 1 and 2 Steam Generator Sleeving Report (Brased Sleeves)", March, 1985.

Exhibit E - CEN-294-NF, "Frairie Island Steam Generator Tube Repair Using Leak Tight Sleeves", Combustion Engineering, Incorporated January 15, 1985.

-There are currently no specific plans for steam generator tube ,

sleeving. However, Northern States Power Company desires to have the' Commission review and approve these specific sleeving designs to permit their use in the future.

In addition, a process for evaluating the acceptability of other sleeving designs is proposed. The process would require a safety 3_ evaluation to be prepared in accordance with 10 CFR Part 50, Section 50.59 for sleeving designs different than those described in Exhibits C, D, and E. This safety evaluation and other relevant descriptive information related to the new sleeving design would be submitted for the information of the NRC Staff at least 30 days prior to use.

Sinnificane Kasards Evaluation-Exhibits C. D, and E provide information to support the requested Technical Specification changes to permit the use of steen generator ,

tube sleeve repair at Frairie Island. These reports provide a description of the analysis and testing performed to demonctrate the acceptability of these designs. Mechanical strength' corrosion resistance, installation methods, and inservice inspection techniques are described and shown to meet all expected NRC acceptance criteria.

Seversi thousand steam generator tubes at many facilities thropshout the world have been successfully repaired using sleeves. Sleeving has been shown to be a safe and effective method of steam generator tube repair for many types of defects.

r EXHIBIT A continued For these reasons, and_for the. reasons given in greater detail in Exhibits C, D, < sad E, operation of the Prairie Island Nuclear Generating Plant in accordance with these proposed changes to the Technical Specifications will nots (1) involve a significant increase in the probability of an accident previously evaluated; or (2) create the possibility of a'new or different kind of accident from any accident previously evaluated; or w

'(3) involve a significant reduction in the margin of safety.

2., Technical Specifications 4.12 and 6.7 Reportina of Steam Generator Tube Inservice Inspection Results ,,

Proposed Channes The stesa generator tube inservice inspection reporting requirements presently specified by Technical Specification paragraph TS.6.7.A.4 are being modified to more accurately reflect the manner in which the inspection results are actually reported, and are being moved from Technical Specification Section 6.7 (TS.6.7.A.4 is being deleted) to Technical Specifiestion Section 4.12 (TS.4.12.E.2) for consistency.

See Exhibit B for the specific changes.

Reason For Channe The results of steam generator tube inservice inspections are presently included with the summary reports of ASME Code Section XI inspections submitted within 90 days of the end of each refueling outage or in special reports submitted within 90 days of the comple-tion of tube inspections not associated with a refueling outage.

This reporting frequency meets or exceeds the-reporting requirements presently specified in the Technical Specifications (TS.6.7.A.4).

The existing requirements are being modified to reflect the actual reporting practice which is more restrictive than the present require-meats.

Because all other steam generator tube inservice inspection reporting requirements are contained in Section 4.12.E. the annual reporting requirements, as modified above, are being moved from Section 6.7.A to Section 4.12 for consistency.

Sianificant Hasards Evaluation The proposed changes to the steam generator tube inservice inspection a reporting requirements constitute an additional limitation. restriction or control not presently included in the Technical Specifications, and p

EXHIBIT A continued are being made to bring the Technical Specifications more in line la with actual practices. For these reasons operation of the Prairie y Island Nuclear Generating Plant in accordance with the proposed chaages would nott

- (1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (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.

Schedule for Implementation

~It is requested that NRC review of this Technical Specification a

revision be scheduled for completion prior to August 31, 1985. This T

would permit the use of steam generator tube sleeving repairs during

,N the 1986 Unit No. 1 refueling outage, if necessary.

At this time, we have no specific plan or schedule for sleeving in

- . cither unit. There is a possibility, however, that sleeving will be

, required in Unit No. 1 in the near future. Experience at Prairie Island and other facilities indicates that tube sheet degradation

.often begins with little advance warning and progresses rapidly. It voul.d be of great benefit to have received NRC review and approval of a.( potential sleeving' designs well in advance of any use.

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