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PowerC 0 R POM A ' SON

May 21, 1980

File: 3-0-3-a-31

Mr. Darrell G. EisenhutActing DirectorDivision of Operating ReactorsU.S. Nuclear Regulatory CommissionWashington, DC 20555

Subject: Crystal River Unit No. 3Docket No. 50-302Operating License No. DPR-72Letter dated February 25, 1980Information Related to Turbine-Disc Cracks

Dear Mr. Eisenhut:

In response to the subject letter, Florida Power Corporation hereby sub-mits the attached report, entitled " Crystal River l' nit 3, Low PressureTurbine-Disc Cracking, Response to NRC letter of 2/25/80". This reportcontains responses to both " generic" and " site specific" questions iden-tified in Enclosure 2 of subject letter.

The Appendix 1 of this report contains material specification data thatWestinghouse considers proprietary. Therefore, in accordance with Sec-tion 2-790 of Part 2, Title 10, Code of Federal Regulations, Florida 4Power Corporation hereby requests the NRC to withhold Appendix 1 of thereport from public disclosure.

Should you require any additional information concerning this subject,please contact this office. ;

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Very truly yours,

FLORIDA POWER CORPORATION

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Ronald M. BrighActing ManagerNuclear Support Services

PYBhewWO9D70

8005230 k NAttachmentGeneral Office 3201 Thirty-fourin street soutn . P O Box 42. St Petersburg. Florida 33733 813-Bc6-5151

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STATE OF FLORIDA''

COUNTY OF PINELLAS

R. M. Bright states that he is the Acting Manager, Nuclear Support

Services Department of Florida Power Corporation; that he is authorized

. on the part of said company to sign and file with the Nuclear Regulatory

Commission the information attached hereto; and that all such statements

j made and matters set forth therein are true and correct to the best of

his knowledge, information and belief.

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/ R. pr. Bright!

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Subscribed and sworn to be.~ ore me, a Notary Public in and for the State1

j and County above named, this 21st day of May,1980. I

kno ~ ~j Notary Public.

i| Notary Public, State of Florida at Large,

my Commission Expires: August 8, 1983

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TSCRN63(Notary)DN-79

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INDEX-

1. Introduction

2. Response to Generic Questions

3. Response to Site Specific Questions

4. Appendix 1 - Westinghouse Material Specification Data -

Westinghouse Proprietary Information

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5. Appendix 2 - Turbine Trips and Overspeeds

6. Appendix 3 - Westinghouse Inspection Report

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7. Appendix 4 - Turbine Operating Environment

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- DOCKET 50-302

OPERATING LICENSE NO. DPR-72

CRYSTAL RIVER UNIT 3

LOW PRESSURE TURBINE - DISC CRACKING

RESPONSE TO NRC LETTER OF 2/25/80

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INTRODUCTION.

This report has been prepared in response to the NRC's letter, dated

February 25, 1980, concerning ultrasonic inspection of Crystal River Unit 3

| (CR-3)turbinelowpressurediscs. This report contains responses to both ,

" generic' and " site-specific" questions identified in the letter.4

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| Florida Power Corporation is a member of the utility industry Disc Integri-i'

ty Task Force. As such, responses to questions contain information and|

data that has been discussed with other utilities for consistency of an-

swers and, in some cases, is considered proprietary information by Westing-,

house Electric Corporation (Appendix 1).

Crystal River Unit 3 turbine was inspected by Westinghouse Electric

Corporation for disc cracks in March 1980 and no indications were found,

i (refer to Appendix 3).

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RESP 0NSE

TO

GENERIC QUESTIONS.

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GENERIC QUESTIONS,

Florida Power Corporation requested that responses to the generic questions

dSked in the 2/25/80 letter be submitted to the NRC by Westinghouse

Electric Corporation after review by the Turbine Disc Integrity Task

Force. This was accomplished and verified by Mr. J. M. Schmerling of

Westinghouse. These responses are also included as part of this report.

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March 14,1980- - - -.

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Darrell G. Eisenhut, Acting Director*

Division of Operating Reactors' U.S. Nuclear Regulatory Commission

Washington, D.C. 20555 ,-

Dear Mr. Eisenhut, -

Your letters of February 25,1980, to licensees with operating Westinghouse steamturbines requested certain site specific and generic information relative to turbinedisc integrity. You urged in your letter that the licensees address the genericquestions and coordinate the responses through an owners' group.

Licensees with nucler> power plants and Westinghouse steam turbines have formeda Turbine Dise Integrity Task Force, with Mr. Wayne Stiede'of CommonwealthEdison Company selected as Chairman. Westinghouse has been working with thisTask Force to generate responses to your generic questions.<

At a Task Force meeting on March 12 and 13,1980, the utilities present preparedand approved consesus responses to each of your generic questions. The TaskForce further directed Westinghouse Electric Corporation to transmit these re-O sponses directly to you. The purpose of this letter is to transmit that information,to you.

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It is our understanding that Mr. Wayne Stiede, Chairman of the Task Force, willalso confirm to you by separate letter, the Task Force's decision to have Westing-house transmit these responses direct to you. We also understand that each utilit-y, in their specific response to your letter to that utility, will discuss the extent to *which they agree with these consensus responses.

If you have any questions on these, please contact me.

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Sincerely,

behmerl ng,''.Dise Integrity Progra Manager'

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W. J. Ross, Operating Reactors Branchcc:I USNRC, Washington DC 20555

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RESP 0NSE

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. SITE SPECIFIC QUESTI0NS

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SITE SPECIFIC GENERAL QUESTIONS -.To be completed in 20 days er prior to startup

! NRC QUESTIONS:

] I. QUESTION

Provide the following infonnation for each LP turbine:.

A. Turbine type

| RESPONSE

CR-3 has one tandem compound four flow, three casings,,! condensing,1800 RPM turf ine utilizing 44 inch last row blades' in each low pressure elt 1ent. The low pressure element is'

designated as a Building 31ock 281.!

| QUESTION

B. Number of hours of operation for each LP turbine at time ofj last turbine inspection or if not inspected, postulated to in-,

spection.

RESPONSE

i 16,369 hoursi

QUESTION.

C. Number of turbine trips and overspeeds.i

j RESPONSE)' See Appendix 2.

QUESTION

D. For each disc:

1. Type of material including material specifications.

2. Tensile properties data.'!

3. Toughness properties data including Fracture AppearanceTransition Temperature and upper energy and temperature.'

. 4. Keyway temperatures.!

5. Calculated keyway crack size for turbine time specifiedi in "B" above.,

6. Critical crack size.,

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7. Ratio of calculated crack-to-critical crack size.,8. Crack growth rate.

9. Calculated bore and keyway stress at operating designoverspeed.

10. Calculated Klc data.

11. Minimum yield strength specified for each disc.:

! RESPONSE1

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The above information is supplied in Appendix 1. We have beennotified by Westinghouse that this information is proprietary.

II. QUESTION

Provide details of the results of any completed inservice inspec-tion of LP turbine rotors, including areas examined, since issuanceof an operating license. For each indication detected, provide de-

! tails of the location of the crack, its orientation, and size.<

RESPONSE

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Florida Power Corporation contracted with Westinghouse to inspectboth L.P. turbine rotor discs starting March 21, 1980. No indica-tions of cracks were found. The Westinghouse inspection report isin Appendix 3.

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III. QUESTION

Provide the nominal water chemistry conditions for each LP turbineand describe any condenser inleakages or other significant changesin secondary water chemistry to this point in its operating life.Discuss the occurrence of cracks in any given turbine as related tohistory of second water chemistry in the unit.

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RESPONSEi

See Appendix 4.;

I V. QUESTION)

If your plant has not been inspected, describe your proposed sched-;ule and approach to ensure that turbine cracking does not exist inyour turbine.

RESPONSE

See Question II.

Crystal River-3, at this point, is on a 1-year refueling cycle.Inspection of the turbine is on a component basis and on a 5-yearinterval. It is Florida Power Corporation's schedule to reinspect

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Although it is not conclusive that water chemistry causes disc,cracking, we maintain our water chemistry below those limits set by2Westinghouse (see Appendix 4).

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V. QUESTION

: If your plant has been inspected and plans. to return or has'

returned to power with cracks, provide your proposed schedule forthe next turbine inspection and the- basis for this inspection,schedule.

RESP 0NSE

! At Crystal River-3, Westir.ghouse Electric found no indications of? Cracks.

j VI. QUESTION

Indicate whether an analysis and evaluation regarding turbine mis-,siles has been performed for your plant and provided to the staff.If such an analysis and evaluation has been performed and reported,

i please provide appropriate references to the available documenta-'tion. In the event that such studies have not been made, consider-ation should be given to scheduling such an action.

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RESPONSE

I Florida Power Corporation did analyze turbine missile probabili-ties. The following references in our FSAR 're given:,

1. 1.3.2.14 page 1-6 (7-11-75)2. 1.4.40 page 1-243. 5.4.3.2.3 page 5-624. 5.4.5.3 page 5-67 (5-8-72)

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