ML18143A450

R. E. Ginna - 1978 Steam Generator Inspection Final Report and NRC Questionnaire Update

ML18143A450
Person / Time
Site:	Ginna
Issue date:	07/27/1978
From:	White L Rochester Gas & Electric Corp
To:	Ziemann D Office of Nuclear Reactor Regulation
References
Download: ML18143A450 (19)

Text

g gg/alt ~y REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

DISTRIBUTION FOR INCOMING MATERIAL 50-244 REC:

ZIEMANN D L NRC ORG:

WHITE L D ROCHESTER GAS

8. ELEC DOCDATE: 07/27/78 DATE RCVD: 07/31/78 DQCTYPE:

LETTER NOTARIZED:

NO

SUBJECT:

FORWARDING COPY OF APPLICANT"S 1978 STEAM GENERATOR INSPEC, UPDATE TQ NRC REQUEST OF 12/09/77 FOR STEAM GENERATOR INFO CORRECTIONS TO APPLICANT"S ORIGINAL SUBMITTAL OF 02/24/78.

COPIES RECEIVED LTR 1

ENCL FINAL REPT... W/ATT SYSTEM>

AND PLANT NAME: RE GINNA UNIT 1

RESPONSES TO STEAM GENERATOR QUESTIONNARE (DISTRIBUTION CODE A023)

REVIEWER INITIAL:

XJM DISTRIBUTOR INITIAL:

DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS 4++4>+++++++++>>>+

FOR ACTION:

INTERNAL:

EXTERNAL:

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NY++W/ENCL TERA++W/ENCL NS IC~+W/ENCL RON GAMBLE++W/6 ENCL KEN HERRING~+W/6 ENCL ACRS CAT B~+W/16 ENCL NRC PDR4%W/ENCL OELD~+W/ENCL AD FOR SYS 5 PROJ+<W/ENCL REACTOR SAFETY BR>>W/ENCL EEB~~W/ENCL DISTRIBUTION:

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~ll(iiek 7SS ROCHESTER GAS AND ELECTRIC PCS L&IEAflaO V

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89 EAST AVENUE, ROCHESTER, N,Y. 14649 LEON D. WHITE, JR.

VICC PRCSIDCNT TCLCPHONC

• RCA CODC 7ld 546-2700 July 27, 1978 Director of Nuclear Reactor Regulations Attention:

Mr. Dennis L. Ziemann, Chief Operating Reactors Branch No.

2 U.S. Nuclear Regulatory Commission Washington, DC 20555 T7 I l C~ '11 r 1.-

C FCD s'l CD

Subject:

1978 Steam Generator Inspection Final Report and NRC Questionnaire Update:

R.

E. Ginna Nuclear Power Plant Unit No.

1 Docket No. 50-244

Dear Mr. Ziemann:

Enclosed herewith please find a copy of our 1978 Steam Generator Inspection Final report for your informa-tion and a update to your request of December 9,

1977 for your steam generator information system.

Also included with the steam generator information system update are a

few corrections to our original submittal of February 24, 1978.

We hope this information is useful for your staff and the information system.

Very truly yours, 7SZXZOO<<

(OF7(

Ginna Station Steam Generator Ins ection Final Re ort June 2,

1978 Rochester Gas,and Electric, Corporation. performed a planned inspection of Ginna Station steam generators from April 1, 1978 through April 6, 1978 in accordance with the Inservice Inspection program as part-of the annual refueling and maintenance outage.

This inspection consisted of a multifrequency eddy current examination utilizing the French Intercontrole'nstrument IC-3FA.

The Intercontrole'C-3FA Multifrequency Eddy Current Instrument consist, of three differential modules, one absolute module and three mixing modules for combining frequencies to eliminate such things as support plate signals and internal tube wall variations.

By utilizing a multifrequency instrument the examination of every tube gave as much information as possible, therefore reducing total examination time and personnel radiation exposure.

The eddy current frequencys and combination of frequencies used for this inspection consisted of the following:

2.

5.

6.

400 KHz Differential - (Defect - thinning and cracking) 240*KHz Differential - (Defect) 100 KHz Differential - (Defect and Dent) 100 KHz Absolute (Defect, Dent, and Sludge)

Cl Mix (240 KHz and 100 KHz) Support Plate - Tube Intersection Defects C2 Mix (400 KHz and Cl Mix) ID Tube Variations

A data acquisition package was developed so that the 400 KHz in-formation could be recorded on the standard magnetic tape and strip chart paper used in the past.

This information was inter-preted by a Level II Data Interpreter from.ZETEC who has done several previous inspections at Ginna.

Also all the frequencies and mixes were recorded on two eight track magnetic tape recorders and the standard (Intercontrole') interpretation frequencies and mixes (240 KHz Differential, 100 KHz Absolute, Cl and C2 mixes) were recorded on a Oscillomink twelve channel strip chart recorder.

This information was interpreted by Level III and Level II interpreters from Intercontrole'.

By having both ZETEC and Intercontrole'ata intrepreters there was assurance that there would be a comparision with previous 400 KHz differential" data.

Also there was a comparison of techniques and frequencies.

The inspection included the following:

~Le A Inlet A Outlet Tubes 1534 190 205 120 Total 2049 120 205 Total 325

~Su ort 1st 6th (Bundle) 6th (Wedge-periphery)

U-bend 6th (Bundle) 6th (Wedge-periphery)

B Inlet B Outlet 1188 151 250 125 Total 1714 125 250 Total 375 1st 6th (Bundle) 6th (Wedge-periphery)

U-bend 6th (Bundle) 6th (Wedge-periphery) 2

Results of these examinations are given in Figures 1 and 2

which includes the 'A'nd 'B'nlets.

Tables (1) and (2) of the report are included for comparison of the last five steam generator

'inspections.

P This inspection revealed that there has not, been continued growth of outside diameter defects (thinning and cracking) just above the tube sheet nor have those previously noted defects grown over the last year of operation.

In the 'A'nlet a very small I.D. defect was found in tube R39C50.

This small flaw was plugged to eliminate any confusion as to characterization and depth.

After subsequent review"of past data and this year' data, it has been determined that this particular 'ID indication has been.there in previous inspections and appears to be a.lap in the tube wall material of minimal depth.

Westinghouse personnel informed us that these material laps are seen in most. plants in just a few tubes and would not normally be plugged.

In the

'B'nlet twelve tubes of the periphery were found to have small

(<40%)

ID defects.

Four of these existed from the January 78 outage (see Licensee Event Report 78-003).

In accordance with our plans and past history these twelve tubes were plugged to eliminate the potential for growth and subsequent failure.

One of these tubes R45C52 was pulled.

This tube had shown ID defect growth from July 77 (see Licensee Event Report 77-08) to January 78.

This pulled tube is being analyzed at Westinghouse RM).

The dent evaluation that was performed included every tube-to-tube support intersection examined including the tube sheet.

3

This program revealed that the dents are all smaller than pre-viously thought,

<5 mil'ls with most being <.5 mills. It appears that this difference may be related to sensitivity settings in previous inspection.

A'iso, the extent (number.of intersections) of denting has not increased at tube supports or the tube sheet.

The sludge evaluation program revealed that the average sludge height was approximately half of what it had previously measured.

This was also confirmed by the water balance done in connection with the water lancing program.

The excellent results of this inspection is thought to be based on the proper operation of Ginna Station's steam generators in accordance with AVT specifications.

Associated with the operation of the secondary side water chemistry this past refuel-ing cycle has been the addition of the in-line full-flowcondensate polishers.

These demineralizers were placed into operation in December 1977 allowing for approximately four months of operation with the demineralizers in operation.

It appears from the inspec-tion results that this modification not only limited the con-cent'.ration of active species in the steam generators but also has helped to limit the intrusion of chlorides into the system which has probably helped to limit any denting problems at Ginna Station.

Another major contribution of the demineralizers is their filtering characteristics which is postulated to be one of the reasons the sludge profile was greatly reduced from previous years.

The actions taken to ensure the continued reliability of the steam generator includes the following:

a.

All tubes with internal (ID) defects were plugged.

b.

Tube R45C52 of the 'B'team generator was pulled to help characterize the failure mechanism of the previous periphery tubes 'internal defects and failures.

c.

A thorough lancing of the secondary side of the tube sheets was performed in both steam generators to remove as much sludge and contained contaminants as possible.

d.

Blowdown during startup and normal operation should considerably reduce the concentration of active species and help maintain proper chemistry in the steam gener-ators.

e.

During startup and normal operation the continued operation of the full-flowcondensate polishers, will assure that the feedwater entering the steam generators will be of the highest purity.

Because of the excellent results of this year's inspection of Ginna Station's steam generators, the steam generators are considered acceptable for uninterrupted use until the planned refueling outage in the Spring of 1979.

An eddy current examina-tion of the steam generators in accordance with the Inservice Inspection Program shall be performed during the 1979 refueling outage.

e-R.oman ~"~~

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STEAM GENERATOR POSITION INDICATION SIZE

(%)

NOV. 1974 TABLE (1)

EXAMINATIONDATE.

MAR. 1975 FEB.

1976 APR.

1977 APR.

1978 IIAII INLET 20 OD 20-24 OD 25-29 OD 30-34 OD 35-39 OD 40-44. OD 45-49 OD 50 OD 631 59 46 31 25 14 52*

655 109 63 38 27 22*

14*

10*

230 59 47 50 31 19*

8*

j 2*

730 39 37 23 8

0 11*

2*

592 26 16 3

0 0

0 0

Total "A" Inlet Tubes Examined At Each Inspection at 400 KHZ 1655 2174 3192 2003 2049 STEAM GENERATOR POSITION INDICATION SIZE

(%)

NOV. 1974 EXAMINATIONDATE MAR. 1975 FEB.

1976 APR.

1977 APR.

1978 IIAII OUTLET 20 OD 20 OD 278 0

10 0

113 0

99 0

Total "A" Outlet Tubes Examined At Each Inspection at 400 KHZ 430 442 3192 268 325

• tubes were explosively plugged Total tubes plugged in A Steam Generator 121

TABLE (2)

STEAM GENERATOR POSITION INDICATION SIZE (/o)

NOV. 1974 EXAMINATIONDATE MAR. 1975 FEB.

1976 APR.

1977 APR.

1978 IIBll INLET 20 OD 20-24 OD 25-29 OD 30-34 OD 35-39. OD 40-44 OD 45-49 OD 50 OD I.D.

490 3

1 1

0 0

0 411 13 10 9

51*

0 10*

764 25 8

9 31*

0j*

719 12 8

0 1

0 0

752 6

7 0

0 0

0 0

15**

Total "B" Inlet Tubes Examined At Each Inspection at 400 KHZ 675 1931 3247 1525 1714 IIBll OUTLET 20 OD 20 OD 1003 2

STEAM GENERATOR INDICATION EXAMINATIONDATE POSITION SIZE

(%)

NOV. 1974 MAR. 1975 FEB.

1976 APR.

1977 APR.

1978 90 88 1*

0 Total "A" Outlet Tubes Examined 39 At Each Inspection at 400 KHZ 442 3247 268 375 NOTE:

Two tubes were explosively plugged in January 1976, fifteen in April 76, two in July 77, and eight in January 78 Tubes were explosively plugged TUBES WERE EXPLOSIVELY PLUGGED 12 FOR ID DEFECTS AND 3 ASSOCIATED WITH PUILING Total tubes plugged in B Steam Generator 59

'~'Corrections to:~Steam.Generator'uestionnaire l.

Under II.

Flow Rate of 33.6x(10) 0/hr (Primary) 6 2.

Under III.

Flow Rate of 3.3x(10) 4/hr Secondary/Generator 6

3.

Page 2a We switched to AVT Chemistry (November 1974)

VI.

TURBINE STOP VALVE TESTING (applicable to Babcock 5 Wilcox (BSW) S.G. only)

Fre uenc of Testin Actual:,

~ Manufacturer

~ Recomendati on:

Power Level At Which Testin Is Conducted Actual:

Manufacturer Recomendation:

Testin Procedures Stroke len th, stroke rate etc.

Actual:

Manufacturer Recommendation:

VII.

STEAM GENERATOR TUBE DEGRADATION HISTORY (The following is to be repeated for each scheduled ISI)

Inservice Inspection (ISI) Date:

ppgj.3, 3

6 l978 Number of EFP Days of Operation Since Last Inspection:

275 (The following is to be repeated for each steam generator)

Steam Generator Number:

In Out In Out Percentage of Tubes Inspected At This ISI:

Percentage of Tubes Inspected At This ISI That Had Been Inspected At The Previous Scheduled ISI:

6>>/47~

Percentage of Tubes Plugged Prior to This ISI: 43-6~:

B

> ~ >>

Percentage of Tubes Plugged At This ISI:

~ o3>i Percentage of Tubes Plugged That Did Not Exceed Degradation Limits:>>o<<

B loo~

Percentage of Tubes Plugged As A Result of Exceedance of Degradation Limits: A o~~

B o~

Sludge Layer Material Chemical Analysis Results:

Sludge Lancing (date):

'>mr<> 3-6.

>978 Ave. Height of Sludge Before Lancing: 4'2"-2" Ave. Height of Sludge After Lancing:

o"->/2" Replacement, Retubing or Other Remedial Action Considered:

(Briefly Specify Details)

None Support Plate Hourglassing:

None Support Plate Islanding:

None Tube Metalurgical Exam Results:

Bs/G R45 c52

II

",.Fretting..or~Vibration.-"in;U-Bend; Area (not".'applicable,to BLW;S.G.)

AS -OF ~4 4

Per centage of Tubes Plugged Other Preventive Heasures None.

No problen of this nature Wasta e Cavitation Erosion AS OF ~4

~Hot:Le (Repeat this information (C.E.) and Westinghouse Area of Tube Bundle (1)

X of Tubes Affected by Wastage/Cavitation Erosion I of Tubes Plugged Due to Exceedance of Allowable Limit (2)

I of Tubes Plugged That Did not Exceed Degradation Limit Location Above Tube Sheet (3}

Max. Wastage/Cavitation Erosion Rate for Any Single Tube (Tube Circum. Ave) (Hills/Honth)

Max. Wastage/Cavitation Erosion in Any Single Unplugged Tube (Tube Circum. Ave) (Hills) for the cold leg on Combustion Engineering (W} S.G.)

/B Inlets b

c d

e 27/

23 0/0 03/.0 0-P" 0 2 st 0/

0 0/

0

~Crackin As Os ~4 Caustic Stress Corrosion Induced in C.E.

and W S.G.

Flow Induced Vibration Caused in BSW S.G.

,~Crackin (Con't)

~Rot Le Inepeat this Information for the cold leg on c.E.

and B S.G.)

lets Area of Tube Bundle X of Tubes Affected I.D.

By Cracking X of Tubes Plugged Due to Cracking X of Tubes Plugged That Did Not Exceed Degradation Limit Location Above

( 3)

Tube Sheet Rate of Leakage From Leaking Cracks (gpm) a b

c 0/

.03%

0/

.03%

0/

100 0-2" d

e

~Dentin (Not applicable to BSR S.G.)

AS OF ~4

~Hot Le (Repeat this information for the cold leg on C.E.

and N S.G.)

Area of Tube Bundle (1)

X of Tubes Affected by Denting X of Tubes Plugged Due to Exceedance of Allowable Limit (2)

X of Tubes Plugged That Did Not Exceed Degradation Limit Rate of Leakage From Leaking Dents (gpm)

Max. Denting Rate for Any Single Tube (Tube Circum. Ave) (Mills/Month)

Max. Denting in Any Single Unplugged Tube (Tube Circum. Ave) (Mills)'

b c

d e

.25 2.8 0/

0 0/

0/

0 0/

0 5-6

- lod-Denting (Con't)

Eu ort,-

'Ma

'n'An 'Sin 1

r

'"qg pp Plate-Levels x'..'Denting' y

g e

Tube in Bundle, Area (Tube Ave) (Mills) (1)

X of, Tubes Affected By "Denting -in Bundle Area A/

B 1

2 3

4 5

6 7

8 g

10 ll 12 5/

5 3

5 3

0

.5

.8/

2

.2 0

TABLE KEY il NOTE:,. All.percentages refer to the percent of the, tubes within a given area of the tube bundle.

Area of the Tube Bundle No. of Tubes Within the Area a.

Periphery of Bundle (wi/20rows for BSW; wi/10 rows for C.E.

and W) b.

Patch Plate (wi/4 rows) c.

Missing Tube Lane (BN only)

(wi/5 rows'.

Flow Slot Areas (C.E.

and W only) wi/10 rows) d.

Wedge Regions (C.E.

and W only)

(wi/8 rows) e.

Interior of Bundle (remainder of tubes)

(2)

Allowable Limit for Wastage/Cavitation Erosion:

40%

Allowable Limit For Denting:

None (3) l.

Specifies area between the tube sheet and the first support plate 2.

Specifies in the following locations: (list the additional locations)

Wastage/Cavitation Erosion:

Cracking:

(4)

Specify the date of the inspection for which results have been tabulated.

4/3-6/78