ML17341B331

Rept of Steam Generator Insp & Tube Repair - Jul 1982 Outage.

ML17341B331
Person / Time
Site:	Turkey Point
Issue date:	07/31/1982
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17341B330	List: ML17341B329 ML17341B331
References
NUDOCS 8208160303
Download: ML17341B331 (64)

Text

REPORT OF STEAM GENERATOR INSPECTION AND TUBE REPAIR TURKEY POINT UNIT 4 JULY 1982 OUTAGE 8208160303 0500025k 820809'DR ADOCK

~G PDR

TABLE OF CONTENTS

1.0 INTRODUCTION

- EVENT DESCRIPTION 2.0 RESULTS OF STEAN GENERATOR INSPECTION PROGRAM 2.1 Steam Generator Annulus Search 2.1.1 Preface 2.1.2 Fiberoptics 2.1. 3 Operation 2.1.4 Video Camera 2.1;5 Comparison of Techniques 2.1.6 Recent Experience at Another Plant Location 2.1.7 Determination of Visual Technique Used in Turkey Point Unit No. 4 Steam Generator 2.1.8 Results of Fiberoptics Annulus Search 2.2 Steam Generator Eddy Current Inspection Program 2.2. 1 Description of Eddy Current Inspection Program 2.2.2 Results of the Eddy Current Inspection 2.2.2.1 Eddy Current Indications 2.2.2.2 Tube Restrictions 2.3 Results of Profilometry Inspection 2.4 Review of Prior Eddy Current data for R44-C57, R44-C58 3.0 TUBE DAMAGE ASSESSNENT AND RECOMMENDED SAFEGUARDS 4.0 SAFETY EVALUATION 4.1 Continued Operation Mith Foreign Objects Present in Steam Generator 4.2 Tube Plugging APPENDICES

1. Foreign Object Retrieval Operations Performed in'Secondary Side of Turkey Point Unit No. 4 Steam Generators, July, 1982 Outage.

2. Description Of Metal Impact Monitoring System Applied to Turkey Point Unit No. 4 Steam Generators.

LIST OF FIGURES Steam Generator A Inlet - Location of Tubes Eddy Current Inspected Steam Generator A Outlet - Location of Tubes Eddy Current Inspected Steam Generator 8 Inlet - Location of Tubes Eddy Current Inspected Steam Generator B. Outlet - Location of Tubes Eddy Current Inspected Steam Generator C Inlet - Location of Tubes Eddy Cur riant Inspected Steam Generator C Outlet - Location of Tubes Eady Current Inspected Gauging Results, Steam Generator 8 Inlet.

Results of Profilometry Inspection of Tube R44-C57.

Steam Generator 8 Inlet Results of Profilometry Inspection of Tube R44-C58.

Steam Generator 8 Inlet Eddy Current Signals R44-C57 and R44-C58 Eddy Current Signals R44-C57 and R44-C58 Recommended Plugging - Steam Generator A Recommended Plugging - Steam Generator 8 Reccmmended Plugging - Steam Generator C

LIST OF TABLES

1. Inventory a'nd Dispostion of Foreign Objects Observed

2. Number of Steam Generator Tubes Inspected

3. Eddy Current Indications Reported

4. Number of Tubes Restricting Passage of Probe Listed

5. Eddy Current Data Analysis - Steam Generator B - Row 44C57 and C58

6. Summary of the Damage Assessment and Recommended Sentinel Plugging

7. Recommended Tube Plugging

0 a

1.O INTRODUCTIOH - EYE OESCRIPTION On July 6, 1982, existing primary to secondary 1 akage in agleam generator B ah Turkey Point No. 4, began to show signs of incre'sing. Over the next approxi-mately 36 hou'rs the rate of leakage increased from about 1.2 gallons/hour to an estimated 5 to 10 gallons/hour. Florida Power and Light Company elected to

. shut the plant down to locate and'repair the source of leakage.

After entry into the Steam Generator B was effected, the source of leakage was identified as tube R44 C57, hot leg. Eddy current (EC) testing detected the presence of an apparent through wall penetration at the top of the tubesheet in the leaking tube. A similar signal, unchara"terized due to its complexity, was 'detected on the adjacent tube, R44 C58, hot leg.

Since the neighboring tubes,did not exhibit dents at the top of the tubesheet, and since a similar leakage event had occurred the previous month in Steam.

Generator B at R44 C36, cold leg, a program including secondary side vi'sual inspection and selected tube EC te'sting was established.

2.0 RESULTS OF;.STEN GENERATOR INSPECTION PRO"=RAH 2.1 Steam Generator Annulus Search 2.1.1 Preface 0

The purpose of this review is to describe the 'echnique used to visually inspect and record the nature and location of certain foreign material(s) found in the secondary side of the Turkey Point Unit 4 Steam Generators. This method was also ised to provide pictorial data for the evaluation of associated tube anomalies.

Intr oduction The fiberscope used by Mestinghouse for steam generator inspection is a current, "state-of-the-art" viewing device. It is a bundle of glass fibers $ n which the light necessary for viewing travels through some of the fibers while the remainder tr ansmit the image. A cable through the center provides a means

'of tip angulation to increase the range of view. The apparatus is flexible and can be directed to almost any accessable location within the working length.

The equipment used for the steam generator annulus search is an Olympus 1F1193 Industrial Fiberscope; Olympus ILK-4 Light Source; and Olympus OM-1 35mm camera with fiberscope adaptor. The fiberscope has a working length of l08 in. and a depth of field ranging from 10am to infinity. The field of view is 65'nd is enhanced by angulation of the viewing tip which can be turned in any direction.. This scope affords the optimum view'provided size is not a constraint. A 35mm camera can be attached to the scope to document any viewed condition. The best "feel " or picture of the situation is seen through the eyepiece of the operator.

2.1.3 Ojeeratfon To prepare for an inspection, the handhole covers and tube lane blocking devices are removed. Mater on the tubesheet should be removed, The fiberscope is hand fed into the generator. The inspector scans every tube, photographing any abnormal conditions. A 360'nspection can be obtained through the two penetrations on opposite ends of the tube lane.

A search requires about one ten hour shift per generator, if no abnormal conditions exist.

~ S 2.1.4 Video Camera A. Introductf on

.. The video camera system used by Mestfnghouse HSD fs made especially for dark tight areas fn a radiation ffeld. It uses a low light level camera tube which fs radiation tolerant and operated remotely

. from a control unit. Except where constrafned by fts size (21 fn. x 1.25 fn.) the camera can reach most areas of the generator.

B. Description At present the system fn use fs the Mestfnghouse ETV 1250 Hfnfature Underwater TV Camera. In addition, a rfght angle rotator capable of 360'otation, and video recorder are used. The camera has a.125 ft. cable allowing the control unit to be in a lower radiation area. The focus range fs from 1 fn. to fnffnity lfmfted only by light which reaches approximately 16 inches above the tubesheet.

C. Operation Scan and documentation of the steam generator require the tube lane blocking device and any water on the tubesheet be removed. A track fs set up fn the generator bundle to shell annulus to guide the camera and a control station fs set up.

This initial preparation time is 4 shifts. It fs anticipated that each scan would then take 4 shifts per generator.

2.1.5 Com arfson of Techni ues Fiberoptfcs fs the preferred method of fnspection whereas the video camera provides an all fnclusfve record documentatfon. The operator of the ffberscope can obtafn a better understanding of the total conditions since the image fs three-dimensional; fs fn color; and fs quite clear with minimum glare, a condition whfch video has trouble controlling. The fiberscope can

'l look from unlimited angles and distances wher'eas the video camera cannot. The video documentation takes about five times as long, which results in more radiation exposure to personnel. Documentation through the fiberscope provides clearer results but 100 percent documentation would require thousands of pictures. 'onsequently, unless 100 percent documentation is necessary, fiberoptics is the preferred method.

2.1.6 Recent Ex erience at Another Plant Location The initial inspection with the fiberscope of a steam generator at another plant, where it was determined that the damage was extensive, resulted in a decision that 100 percent documentation would be required. All efforts were therefore directed to a video camera. inspection. Problems associated with'the video results at this site were poor lighting, glare or burnout, and lack of cl arity.

2.1,7 Oetermination of Visual Techni ue Used in Turke Point Unit 4 Steam Gener ators Base'd upon the initial fiberscope inspection of Turkey Point Unit 4 Steam Generator B, it was determined that a fiberscope was the inspection equipment which would provide the optimum data for a technical evaluation of the tube anomalies.

In accordance with this determination, the fiberoptics technique was used for the visual inspection of th'e annulus region in each steam generator, and for the. photographic recording of foreign objects observed in these steam generators.

2.1.8 Results of Fiberoptics Annulus Search As a result of the fiberoptics i'nspection of the steam generator. annuli, a number of foreign objects were observed and photographically recorded. A list of the objects observed 'in each steam generator is provided in Table 1.'

photographic record of the objects has been prepared and has been presented in

TABLE 1 Inventory and Disposition of Foreign Objects 0bserved in Secondary Side of Turkey Point Unit No. 4 Steam Generators - July, 1982 Outage Steam Generator Size Location Position I. Weld Rod 8" 1 ong Outlet, R43-44, C33 Protruding from bundle Yes

2. Flat Bar ] II x 2II Inlet R35-36, C18 Protruding from bundle'es

3. Coiled wire Very Small Originally R45 now Between Tubes No or strip Mass about unknown 1/32"xl/4" X 2" /

4. Coil ed Very Small Unknown, sighted Between tubes Wire about 1" long first day of inspection only 4B 1. Bolt 0.375"x1.0" Outlet, R42, C31-32 Hedged on Tubesheet Yes

2. Flat Stock Outlet, Wedged at an angle II II II 0 5 x2 X6 R43, C32-33 Yes

3. Stainless 0.375"x6" Inlet, R44, C57-58 Wedged between tubes Yes Steel Tube ..

with wing nut Inlet, Pin 1.0" diam R45, C48-50 Loose on tubesheet Yes x2" long adjacent to tubes

5. Weld Rod 8 II Inlet, R44-45, C53-54 Standing, adjacent Yes to tubes 6 "Gl ob" l. 0" Inlet, R44, C55 Wedged on Tubesheet No

7. Flat Stock 0. 375" xl. 5" Outlet, R43, C33-34 Between tubes Yes x 2"

8. Pi ece of .5" x 1.0" Outlet, R42-43, C32-33 Between tubes No metal/slag

9. Hire 0.32"xS" long Inlet, R44,C56-58 Loose, on tubesheet Yes

10. Deepwell 11/16" x Near manway side tube- Loose, on tubesheet Yes Socket 1/2" drive lane blocking device l

4C 1. Pin 1" diam x Inlet, R45, CSO-54 Loose on tubesheet Yes 2" long

2. Meld Rod 8" long Inlet, R45, CS4-55 Standing between tubes Yes

3. Tapered 1. 0" xl. 5" 1 ong Outlet, R44, C34-3S Medged, on tubesneet Yes Plug

4. Pi ece of 0.5" diam. Outlet, R44, C55-56 Hedged on tubesheet Ye Metal

5. Mire 3/16"xlO"long Inlet, R45,C53-54 Located ia bundle'e

6. Hire App. 1/16" x Inlet, R45, C53-54 Leaning into bundle Ye 10" long

~ I ~

~

t album form to the HRC staff at the joint NRC/Florida Power and Light Co./Westinghouse Electric Corporation meeting on the subject outage on Friday, July 23, 1982 in Bethesda, Maryland.

2.2 Steam Generator Edd Current Inspection Pro ram 2.2.1 Descr i tion of Eddy Current Ins ection Pro ram limited multifrequency eddy current inspection program was pezfozrre8 in the inlet and outlet loop of each of the three Turkey Point Unit 4 steam generators as a result of the July 1982 primary-to-secondary leakage event.

(The primary frequencies were 400Khz and 100 Khz, both in the differential mode.)

In general, the program consisted of the eddy current inspection of unplugged tubes in the periphery of the tube bundle plus additional tubes in the vicinity of observed foreign objects. The locations of the tubes inspected in this program are shown for each leg of each steam generator in Figures 1 to 6, inclusive. The numbers of tubes inspected are summarized in Table 2. In

'team Generator.:,B inlet, where .the tube leak was found, the tubes were inspected through the uppermost support plate (tube support plate No. 6). In addition, any tubes restricting passage of the standard 0.700-inch diameter probe for this plant were gauged with probes of successively smaller diam ter (0.650 and 0.610-inch) as required until. clearance was realized. Additional tubes, 'surrounding those found with 0.650-inch or smaller restrictions or surrounding tubes with reported eddy current indications, were added to the original program as required.

I In Steam Generator B outlet, as well as in both legs in each of Steam Generators A and C, the tubes were inspected only through the first support plate, and gauging was not performed.

l

)

C TABLE 2 TURKEY POINT UNIT 4 JULY 1982 OUTAGE

,/

NUMBER OF STEAM GENERATOR TUBES INSPECTED Number of Tubes Extent of Steam Generator Inspected Ins ection A inlet 201 First Support Plate A outlet 171 First Support Plate B inlet 167 Sixth Support Plate B outlet 106 First Support Plate C inlet 148 First Support Plate C outlet 163 First Suppor t Pl ate

K~ ..-

V A 33 0/74s TUBES PLUGGED I ets 2/78s TUBES PLUGGCD 8 83 6/75s J C

TUBCS PLUGGCD DATE HOT KHOMHs TUBES PLUGGED K es 2

8/78s TUBES PLUGGED SHOP MELD, HL HISDRII LED SERIES D I SHOP MEl.D L 79 0/79s TUBES PLUGGED E' 5/76s TUBCS PLUGGED H 72 5/88s HECH PLUGGCD F

9 H

02 l31 I

II/76s TUBES PLUGGED 7/77s TUBES PLUGGED 7/77s IsELD REPAIR HL, E/P CL H

P 27 38 11/88s 11/8I HECH PLUGGED sIIECH PLUGGED FLA-.A QNNR COtORf

0) N lD (9 0) t t t P P .LA F)

QQSQQtAU)

.CO W N N U)

0) N R N 0) W U) (0 0) N N N NU) Vev<<RR(9(9p)(URBAN-

0) N I --0)t I8-(9 COLUMNS sxr 4S

<<gpl I tst

<kAoeos 43 HMH zzxLt Gecc~

gg HH HHM IP IZCJMG LMM 3g MHH 38 37 36 34 33 32 31 P A 38 2g OA AAAAAA PAAA AA 28 MA 1 A 26 24 22 28 PHPP is 16 17 PHHP A LOOOPA NP H HHH JJJ JJJJ J B bb bbbbb A PNNS LLLMP JJJJ NXXJLH Lee 14 13 JJJJJ AH Zccdgg 12 11 JJJJ bb I cccpp IHNJJJJ NH JJJJ HJ N OGG PCOCCP GOHGOGP 18 g JJJJ LJJJ H

NM PPHMM BEMJ Je JLJJH F JM 8 8 LJHH MM P HLLLB XX GQG QPOHGGOO zeeMMMeeo 8 LLLJ HH LLLHH MtMM LLXX HLJILH O HMII b JLOOX M XI JJJHL PPob LZLJL ILXOOHLOLZIZI OZOJJL LO XLL ZCPOOHM00 oxooLGHMf/ 6 LJLI LJ H S XIXCO OZZIXJLL t bbbbIOOBOC JJL ZXXLL H

ccccccccfH LJJIJL LJHHXb LZIZHMHZIIZZO t LLXXZZ 4 3-JJJI JLI LJxxxz LbxxxJHMxxxIz ~ xzxxzoL xzxeoNQIxIxzx ~ MxzIxBIxeeJ JB xxzJL GGQGGQGGQ p LLt IJ J Jz Jt l LLLJIIxxLIxczIIxLIxxazeIZXIxzozzzxzeeozGIxozzxLLXIIxxzzxeeoooeoIIXGLLaooooooeooxL 2 rrrrrrrrrrrrrr rrrprrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr + 1 ROWS

+--- MAN@AY FIGURE l NOZZLE ---+

mmKEr POINT UNn 4 STEAM GENEIN'IOR A INLLT JULY, 1982 OUI'AGE

A 33 G/74 4 TUBES PLUGGED IJ leo 2/78l TUBES PLUGGED B

C 83 1

8/754 TUBES PLUGGED DATE HOT KNOMNg TUBES PLUGGED K 86 2

8/784 TUBES PLUGGED SHOP MELD, HL HISDRILLED SER1E'S F'2 D

E' B 131 I SHOP MELD 5/76p TUBES PLUGGED I I/78> TUBES PLUGGED 7/774 TUBES PLUGGED H

P L

H 7Q 72 27 38 4/704 TUBES PLUGGED 5/684 HECH PLUGGED

'll/80) HECH PLUGGED

'l l/814HECH PLUGGED H l 7/77> MELD REPAIR N, E/P CL

0) W lA lt) 0) N U) (9 0) N. lA R 0) N lO R 0) ~ lA N 0) ~ tA N S N lA R S N lO F)

. QRC)RMC)f l r t t QQ'Q(OQU)lOMNMV<<~~RF)NRRblNNRhl-----St tAN-,

COLUWNS N lo < N 6) M Q C N

~

Q < < < < P) N R P)

OX PXj XX I XL-4~

itd /X H

O'Pieeee 43 XZXmLGGGGM HMM IP XZCJMO LMM MMH 3S 36 37.

XCC 000 000 34 33 32 3f A P A 38 bA AAAhhh PAAA hh 28 A

Lh BB B

26 ao A 24 23 22 2f P

PN PP l8 19 PN t4P A

bb b LbbbPA b bbbbb A NP M HHt4 PNHPLLI HP t6 JJJJ B B NXZJLHjf JJJJ LB LGGL ~ P'cce/pr JJJJJ B AM bb L C C OP4tt

~2 l t JJJJ

~Ht4 J J J J b POOOCD l8 L GGHGGGP NN JJJJ PPP HH P GGG XI GPGHGGGG 8 JJJJ BCMJ JG JLJJH B LJHM P 0 NLLLB 000 IGGMMHGGQ 7 LJJJ LLLJ LLL HH M1HH LLXX JJJHL PP+b LXLJL La xcpooMMOO 6 MH MLJXLH b I MMXX d Jl OOX ILXbbHLbL IXIX OZOJJL XLL oxoo~L.CMH IX S LJI I LJ M I-IXXHHMZXXZZSLLLXXIX XZ XXXCO OXIIXJLI lbdbbXbdddOJJL ZXXLL 000000001M LJJXJL L JMMZS LSIIX JHHZZXIZ~ IXIXXOL IXXGGNGZIXXZX M HIXZXBXXGOJ Jd XZX JI P J JJI JLI LJXXIX LLLIJJJIJL LLLLJXIXXL ZZQXXZZLIZZOZQZZXXXIQIXIXIGGGIGZIGIZXLLIIIZIIXZGGGGGG QXXZGLLO OGOGOGGGG 0000000GOZL 2 FFFFFFFFFFFFFFFFFbFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFfFFfFFFFFFFFFFFFFFFFFFFF +

NOZZLE ROWS

+--- HANMAY -+

FIGURE 2

'IIED'OINfUNIT 4 STEAM GENEIQIR A OYEZ

.Y 1982 GUTAGE

I

~ ~

~ 6, ~

'i TV- 5 Pa.VGGEO PR7OR TO It/7S 0 It'77 'IVSCS Pc.'JGGat Bi. = ~ BARK HOI.E PLUG HL~P CL 2/78; I S4"= VCLO ta P

70 28 6/78.-

TVS. S PLUGGED

'TUBKS 2 LUL-Gp SPREES

<5 Gs 5

0/-.S, Sl. 5 .

0/6 11/. 5.

B nK HOLE TIRBK5 PLUGGKQ 7 "8- 5 Pa.U~U

'TUSKS PLUGGED ILUCS~.CL R S

T U

'B S2 lB 42 4/70:

5/BBI 1UBKS P VGGKD tICC~ Pa.UCSCD I I/80.- HCCH PLVGGM' 11/BlltIKCt'. PLUGS 0 FLAB 7/7"., UK V RCPWlP V I I/Bl:II/P. HN 0.': T 7/. -.; TUBKS P.UGSKD tl S 5/82; IICCH PLVGGEO

~

-g{0 ~% 0{O-(Dl lflP) Qt lAP) COr tfl{O Ql U) R Cot tfl{O 0) I N{O-Qf N{O-St, tfl{O-

{... m t ~ tv t > {0 {0 {9 {0 {0 lA lfl lfl tfl U) V % V W V R F) P) F) P) N R N N R COLUMNS

{I C'

6 {0 {C VlbJ)Q)Kl{0)V!R S){O]

'i'<R.C.'O'P

{Ga{

)

2 I

[

! I l el~! hl Q {0!{0 V N Q m {0 e N Qt{O {0 W N GI 1

I I

II I

l I ~

I I

I I g I

Ia A I

I Jp p aaa//

R I I I

'NNVU RRTU "L I l I g/ LJ,WW'A v

psa I 6Alf p 'r j'.8

{0V hl

+ 4S

'43

'@II'IT sfg

!II!I U

~

a V

I l)tr)

TN Ng 38 30 SS a

SSA

~A UN li;

I I 1.'

I Nt'U. S AS

,3, t L LLL

/

~

~

NRA 2'

~, +AA

~r, ~~

I a , ' I C

~

~

6 aNNP 6 ~ ~

A~AA 'A',,

I 2~ ~

A A IIAAA2 A g/L'S

I P tR'NV Nf 4IA A *

! 6'UN ~T~ S~~

A A

a I A

A A.

A

~

A I AA AA AAAAA AAAAA A AAI .

26 27 22 li,s~~ I 2

ATHA, HTAT A A'T'T

~ ~

k I 'f.LitJ.

A.

Al A LJ Q. .SssL-'9

~sssSSU.,

.20 8

S~ )6

~ ~

f 6

A TUI I 7

$ 6.'i:~g3~NL ~ A AAA TTUUA PR 2 UN I~~ A hh, 4+ T TUUUL I Cj

~

Rt LLL 1

Wr LsL Ri LNLJCr A T

.I

~

A

'r TA ~ ~

U U'taA+X

~

A A U LLLLLT'

~

• APE AS'T ~ 'T s

I 'T a ~ a

~

~

~ ~

~ a f: ~ ~

r a RR~LRLLLIl R~L~LL L ) Q~ 0 RR A

'iSITLL 6 ~

.T

'PL

~ ~ ~ ~

~

ALLN*'IT TIS~AALIS LLI g+ NLLLLL@+~

LA ALLJUAL

~ ~

NL T SUTT II I RRIIR L ~ I " 'LLLLI RAALL SOLI LLI S 4 L I LLLLLR S ULPl LLLP UI+ TLLg Nt LLLL ~p 6

~

RQRRL LPa t Ua TNLL I LLALLLNPSa NLAS ~ I I LI Lt LLL LL LLLI LL R Lt Sl P RUI SLI LLRJ SP PR J J J LP UPNLI LL.LLLLLLLN NLI S I LI I LLI Lt I SLLLI LR L I LLLLI SLtICISSt LLLLLLNRRNLLN NLI LLLLa

~

JJ J J Jg

~

J J 'JJ J JJIXIXXLI J J JI LLLLLLI LLI PI.MKL..ILLLLLILLI S'LLLLt LI LLLLI StILNLHSLI LLI I LNRR'LLLPLIL ILLLPPPR J ' J JJ JJ JJ JJ JJJZXZXZJ LLI LLt.L.NIXIXXXt.LLLLLLLLPI IXLLLLLLLl-LLI XIXIIPLLLLLLLLPPZZIXLLLLLLLLLLPNP 2 JJ JJJ JJJJJ JJ JJJJ JJ JIXZIZIJ J JV J J J JJ JXZZZJ J J J JJ JJ J J JIIXIIJ JJJJJ JJJ JJIIZZ J J J J JJ J J JJJ J J + '+'---

+ ROWS MaNMAY FIGURE 3

'IUIUKY POINI'NIT 4 STEAM GENERA'mR 8 INLET JULY, 1982 CUTAGH

0 P

~ I

~ ~

522 TU=ES PLUGGED PRIOR TO 58/75 H 9 I C/77< TUBES PLUGGED I 8/, 5; B>RE HOLE PLUG HL-E/P CL 70 2/78@ TUBES PLUGGED 1 SHC> tlCLO 0/75'tRC HOLE'LUG~SCL H

P 28 8/78; TUBES PLUG~GEO SERIES <W 1 R 52 0/79: TUBES PLUGGED 5/7ds TUB 5 PLUGGCD S 5/80; tlECH PLUGGED

$ 2<

45 te I

9/7ds II/ TUBES PLUGuCD

. dg TUBCS PLUGGED 7/77'lELD REPAIP.

7/77'TUBES PLUGGED T

U tt M

56 W2 I

5 11/80 tIECH PLUGGED 11/81 tICCH P'GGrD

'l l/81 ..M/P. HL OIILY 6/BZI tlECH PLUGGCD FLA-B g>f u>+ ef Nm 0)i NR St N(9 0)NMN

, ~ ~ ~ ~ tO i i f i f ~ ~ g ~ iO N lD ln u) ln V W m a a N l9 F) P) P) OJ Cd (U Of R (ol(c la[ NINGl miIOi 'tiN St

~~N Ql<

@le I (0 r1 RG COLUMNS iQ t )00 C3 COt I

I ilili LSIUNNNUPklRTIIN$AI I I I

46 AAPVR ~ R .WWW Al tI AAA R R A

A A S PS'WWPI 43 t'A u '9 A

ll R VT 37

~

I SSA 36 36 A'li As fLL I-H li

,::I; NH AAA AIAA AUA A

A AAA S I ~

m LLI Ul LL/ +T~

uuu I p. P -+s mv

. 34

'6II

~ I ~ I jg l: tNR

~~. 'AiA mA AAAA,

~

NN A A I HN~t4 " ~A ~, AAAAA *AA "L~~g aAl AA A

~<

I HHWNN LLLI. I A l. I I ,

~ ~

AAAAA .'+

l S

A, H ATHA A,

A AT'T T

~ I ~

AAAH ~

23 I

HTA'T A.

.s.--

sssL-." Za I I I .l Asss . i8

) Q I ~ L I AAA Ap AA, A

A

-t Tv ssv.

'TTUU ~ RR T TUVUI S...

T RtILLL I

6 )S I7 p ~++

~ L I..l

..-~I- I 'TA Li.

,A U RLLNI IITL ULLNNg.g 12 1.3 ST-: . V L.Lt.LLT TPP~S A -' A ie

~

~

T+q RPLI RLLLlf

~

~T~

. . I P

RRRT~ T'T ~

J l .

R'H~ TL I A

s, ~~RL ATAA,A~ RRt A .LfJ RL~I - . T U

L I RLLL LLt T RLLLLL'R~ 8 S SI

~

~

TT S JTTLLA RT i R'RRRLL A&A NL

• LLNATT T I S LLI LLNRAAIL I S S

AAL LLI I-LS IS A

LLI I LLLI L I t L

LPL I LLLI R LLLl LLRLl Sl I

S U

V I

E 'TL L LLLP U Q SLLLLRV<

I TLL HLLLLL l'.L NLLLLLLQ/

qL't'LLI 6

RRRRL t PLI V TNLLILLALLLHPSIHLAS LLRLLLLLLl RU SLtINISSLLLI LLLNRRNLLH Lt LL SR ~ PRLJJJt LPs VP NLLLLl I I I I I I HI NLLS LLI LLLLLLSI LI NLI T JJ JJ JJ JJ JJ JJ JJJ J J JLLLLLLLLLLLPt"HKLtt J J J JJIXXIXLLLLLLLI LLLLLLLLLSLLLLI LLI I LLI l I StILtILtlSLLLLLLLNRRLLLI L PLLI LLLLPPPR JJJJJJ LHIIZIIXLLI-LILI LLPXXXZI LLLl LLLI LLXIXXXPLLLI-LLLLPPZXIXLLLLI-LI-LLI PHP 2 J J J J J J J J J J J JJIXXIXJJ J J J J J J J JIXXXXXJ J JV J JJ J J JIZXZJ J J J J J J J J J JZZXZXJJ J JJJ JJ J J JZZXXJ J J J J J J J J J J JJ +

+ .'OMS e---,NANMAY FIGURE 4 NOZZLE -+

'IRKEY PODir UNIT 4 STEAM GENERA'mR 8 OUTLET

~ ~

end, Tvocs pLUGGEn 7/77, TLBES PLUGGED 00 0/76t Tvocs pLUGGt7t 2/70p TVtlES PLU66EO 2

6 I/70t ~ES PLV66CD 6/70t TLAES PLVGGCO d/70> Ttecs pLUGGEO 4/70) TtA3ES Pt,VGGED SPREES 2 0/70'INES PLUGGED 0/7dt CP 6/70 VR tL I I/70t TlÃ)ES PLVGGCD 6/00 p tICCH PI.UGGED FLA-L OS 6 In 7p 0/7 7 I Ttecs pLUGQED I I/00> td.Ctt PLUGGCO TVOCS PLUGGED I I/d! I tICCII PLV6OCD 0 4/77'tdlES PLUGGED I I/dl >II/It Id. ON.T 2 7/77) ttIIIC tLC H K/P nttTLET

~ 0) & lA N 0) > lA (9 0) & lA Cl Q N lA R 0) & lA N 0) & lA N 0) W lA R Ol & lA R Nt I l Q)(0(0(OQlAlANlAlAW< W < <RNRRNOJNblNOJ-----

- 0) & lA P) ~

'{OC)mMt Ol UMNS KMOOOODDDD R

/CC S R DP T C'jfTL 4S SSS/8 43 LS TRSSSSSS SS A RN SSR L R 4e N S AV~~~ 39

"'8 36 37 L graf

/ALL 1 34 33 LL 32 38 28 29 26 27 24 23 5 b 22 2e 2'8

$ 9 HM HHH A

Ab AA 5

bK R RKKK !6 )7 HMHH S KKKKK HHHH 8 8 KKKKR

+ptMHHMM HHMHM 8

dMHb KKKRR Rt KKKR 12 jflSHMHL SSSM 8 SM BHH K EI8 8 RRKKK ~

RRRRKKK 8 g SASS R H R~ 88 ~ BEB RKHR K I f NR LRNLTL NBB MLN 8 RRS b bPKR K RRRI R~H 'TN SHI H5 KBB~TH~B 55 bLIb RRR KKH Nt KK Khott HR 6 w

7 LHNLLL'f bLbN SKRKbbSIRKL K RRRLbdd SHKNH NbTIK55555HNK KKK NLKKH HLNLLLLT LKKKK NN Kl KNK SKLKLSKNt Kt LK KRKLbl MKdKbKOKNI555dbbtKHKKN LKKKK NNLKKHF HMHHHLKILLKH LKKKK HNNLLKLKSSKXKLSKHLKLLK KRKLKLBKBKKKKKBILKKKLLIKKKKKKRRLKKKK HLLLLLKLL.LKLL LKKKKNHNKLLKLKNXXXXXLKLLKKLKKH JXXMXLKKKKKKKKLLLKVKLLLKKKKKKMMLKKKKN HNLKKHRR HHLKKHNHNHHH 2 3 FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

+

ROWS

~ NANMAY FIGURE 5

'mRXbY POINI'NIT 4 STEAM GENHN'IR C INLEf JULY, 1982 GUTAGE

0/7hJ TVOCS PLVOOCD I OO 7/77J T1ICS PLVOOCD DO e/7aI PCS PLVOOCD II~ t/7II TlXICS PLVSGCD SERIES <<

z I/7OI T1eCS PLVO~ OZ O/71I TLHCS PLVCC~

S O/70 I TVOCS PLEAD Lh hl7OI t 9/7OJ TLSCS PLl&OCD I I/7OI TM)CS PLVOOCD I O/7III TVOCS PLVGOCD CP 6/7O S/IOI IICCtI PLVOOCD IIR N 05 t

C 1/77I T1RICS PUKOCD Sd hh tiI I I/OOI C%:CII PLVOOCD FLA-C t

O 7nrJ ~

O/77 J TVOCS PLVCQCD h/77 J TlbCS PLVOOCD tlCh.C ta.. re amer 11/el JtCCH PLVOOCD I I/Ol JIIIII tL Oth.T NR 0)NNR 0)>lAP) Q&lA(9 SNU)R $ >SCl $ >SN

6) Q (0 Q NR M lA LA 0 1 ~t 'f '1 0) 0) (9 R 6) CJ OJ R R N-COLuVNS QDDDD RT C S /RDP/ TQC' I LSCS/g J S TRSSSSSi~SSTP

/+A RN ) sV~

L T 4e "'9 gN T NR 36 37 T S 34 33 LL 32 31 28 29 26 27 24 23 0LL 0 8 22 21

.19 16 17 MM 0 MM A 8K HMH Ab AA RKKK HMHH 8 8 8 8 R S KKKKK KKKKR 14 13 HHH Pf HMHHH 8 BMHB 8 KKKR RLKKKRJI 12 11 I MHMMM I SHMML.

8 SH 0 8HH K BBB RRKKK/'P RRRRKKKJII 18 SL. SSSH 8 BB ~ 88 ~ BCB BB RKNR KKI L 8 LL SRSS R 8 S M TH R

KBB THt-IB KKN K

'THR HBB 8 RRS ReH R I RHI TL M N bl 0 0 KR K RRRI 'bbb SHLHB NBT 00 b~'b K00000HNK RR KKK HLKK HLKKH R 6 ~

LHNLL LT K bN StCRKbb HI Nl I LLT LKKKK HH KI KNK SKLKL.SKNLKI LK KRKI RKL K NHNLLKLKSSKXKLSKHLKLLK KRKLKLBKBKKKKKBiLKKKLl SNKNM bLMKblCbKbKN 000000 KMKKN I

FFFFFF'FFF'FFF'S3 LKKKK HHLKKHP 1KKKKKKRRLKKKKHHLKKHRR I HHMHHLKLLLKHLKKKK KKKKNNNKLLKLKNXXXXXLKLLKKLKKH JXXHXLKKKKKKKKLLLKUKLLLKKKKKKHHLKKKKH HHLKKHHNHNHH t1LLLLLKILLKLLL FFFFFFFFFFFFF F FFFFFFFFFFFFFFFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF NOZZLE ROWS

+--- HANMAY FIGURE 6

-+

'IURKIY POINT UNIT 4 STEN GENERATOR C VJI'IZl'LY 1982 QJTAGE

Results of 2.2.2 e Eddy Current Ins cotton

~

2.2.2.1 Eddy Current Indications

~

Current '(wall loss) indications were observed only in Steam Generator B.

'ddy The reported indications are listed in Table 3.

TABLE 3 TURKEY POINT UNIT 4 - JULY 1982 OUTAGE EDDY CURRENT INDICATIONS REPORTED I~

g ~ Eddy Current S team Genera tor Row-Col umn In die ati ons El evati on r

B inlet 44-57 (1eaket ) 99 percent, Top of tubesheet B inlet 44-58 99 percent Top of tubesheet B inlet 44-56 56 percent 10 'bove tubesheet B outlet 42-31 29 percent 5" above tubesheet B outlet 42-32 29 percent 5" above tubesheet B outlet 43-32 32 percent 4" above tubesheet B outlet 43-33 25 percent 4" above tubesheet B outlet 43-34 . 38 percent 4" above tubesheet B outlet 41-32 <20 percent 25" above tubesheet B outlet 41-32 <20 percent 40" above tubesheet Mith the exception of the tube at R41-C32, the observed indications were at tube locations and elevations which have been correlated directly or approxi-mately with the locations of foreign objects (See Section 2.8, Table 1.)

h 2.2.2.2 Tube Restrictions

~ p Restrictions to the passage of the eddy current probe were noted in each of the steam generator loops tested. As noted above, gauging with smaller-diameter probes, as required, was accomplished only in Steam Generator

J.

B inlet, since the eddy current inspection was initiated in this leg, where the leaker was located, prior to the availability of results of the secondary-side visual examinations. As these results were made available and it became evident that the leak as well as other reported indications and tube damage were associated with foreign objects ob'served at or near tube sheet elevations, further EC inspections were made only in the region of interest i.e., up to the first tube support plate, in order to reduce unnecessary exposure. The nunbers of tubes restricted to the various-sized probes are listed in Table 4.. The locations of the 0.650 and 0.610 inch restrictions in Steam Generator B inlet are shown in Figure 7.

2.3 Results of Profilometry Ins ection Two (2) tubes in Steam Generator B and thirteen (13 tubes in Steam Generator .

C were reported as possibly having bulges (detected visually or by the eddy cui rent inspection). A special inspection of tnese tubes,'nd three (3) adjacent tubes in S/GB was performed using special probes designed to provide data on the profile of the tubes inner diameters. The purpose of this study was to verify and map the contours and orientation of the reported bulges.

The five (5) tubes inspected by this method in Steam Generator B were the leaker (R44-C57) and four adjacent tubes (R44-C58, and R43-C55, 57, 58).

Evaluation of the profilometric data clearly shows bulges in Tub'es R44-C57 and 58, where the largest bulges were observed visually, but does not show bulges in the other three tubes in Steam Generator B. In tube R44-C57, the maximum bulge size (inner diameter) was measured as 0.799 inches. This is 24 mils in excess of the nominal tube I.O. of 0.775 inches. In tube R44-C58, the maximum I.D. of the bulge was measured as 0.802,inches. This is 27 mils in excess of the nominal tube I.D. The orientation of the bulges was in the direction of the tube bundle periphery, where one of the foreign objects was observed lying on the tubesheet. Plots of the resulting data for these two l

tubes along eight radii at the elevation. of the maximum bulge radius are shown in Figures 8 and 9.

~ ~

A 122 lU""ES PLUGGED PRIOR TO 18/75 H 9 1 Or 77'TUBES PLUGGED C I 8/75'ARE HOLE PLUG HL E/P CL H 79 2 70t 'YUOES PLUI'GED SERIES 44 C . I SHC+ MELD P 28 8/78: TUBES PLUGGED F I 0/75q BLARE HOLE PLUGS HL,CL R ~

52 I/79i TIIOCS PLUGGED H 3 5/78g TUBES PLUGGED S 48 5/00p IJ HCCH PLUGGED aS 8/70> 'rUOES PLUGGCD T 50 HCCH PLUGGCD Ft A B

'I/00>

SQ II/.Op TUBES PLUGGED U 42 II/Ol;HCCH PLUGGED K I 7/77'ELD REPAIP. V I 'l l/OlgM/P. HL OIILY L 3CW 7/77'UBCS PLUGGCD M 5 0/OZi tlECII I'LUGGED

-Qt V)Fl-$ &iAN-SASH Ol>'NN-Q>lDP)-0)NM(0 0)&NFL-SP SN SASH~

C Q C) Q) 6) W N N N (0 (0 (0 (0 lA lA lA lD V V V % V 00 W 6) M (0 0) F) P) g9 PJ QNNg~~~~ N C.'ll I

g) ~.

~!~IN!~>>I<i<<<<~<<l> II<<N l

<I<<<>>.

> <!~

p)

<<!<<I~ ) g N <<<<N ~ I << ~

CDLUNNS.

l l }ill} l LOVNNNVCIRRTVNONL - - ~ ~ ~-

I OOAAOUR ~ R L OWW'Lt l AAAO R pswwa AAAA A A U TO l

OQO OTO A A S U )~4Mt OOO ONO

---ll - ..',.- <}

.I I SNN ONO A R

ON 0 ll I,'

jl  !~

TN SSA UT NNO SU 00 I 36 37.

NNU AS LLL J 1 I

) NNN AVA A ~t litULLLLL I.NI'i.L L~tt 'g o3

! I NNONNR NNNRN J NNNN ONNN 0OPt'IR

~ NNR

'.~

-WLtlg+iii *

~ -

I

,.+'

+Cia A AAA A 'T A

AA A

Alt ~

Aaa A AAAA A +I

~ [-

r A

A I AA AA A

O OOOS...sN + +Q~ 3Q P8 2g

~

.~3 }

AAAA l

I goo NNI4NN Nu NNN S

AAAAA AAAtt A

r-

-r r

OO

~

0 4..'"+

0 D~r

~

M 26 24 - 23 NO 3@~ S

~ SSN 28 ON

/

tf0 tiR N~ UI .~

~ ~ I

-.j=.': 2 N

i.-t-<+ssrl '

' --}9

}8}7

~We +MIj~I TU SSU

--g}3S TOU 6

~

'J"I 1" A'l- AAA TTUVtRRO '}

-lht.( A +-~Q

. l-I TITUUVLS, TQRIILI )

.Ol L }

to LPP L'LLNLO TA ,A VQVLLNNOO }2

,Ot TPP.

'QTRRRT~, ~ <A ASTtT A VILLILLT}0

'LI .}8 I;N .T.

. TTT S'JTTI I A Or RT} RRRRLL A

}ATAA A, A RR A Rl ALLNATT Nt ~LLLt I NRAALLI8 RRRRRL LPI L. U TNLI lLI ALLLNPStI Nt AS Lt LLLLLLL T

I..l.

l S S

AAL LLLLLS A

S TT s

LI L

I LPI RL LLLLLR S U LLL LLLR SLRU U E'LLLLL Sl

- -lv T

TLL 1 LLP U LLI L

RU TLl I ,

RRI LRLI L L NLLLI L NI I t LLLLLT RLI LLLt.LRO LLL LLO 0

0 8

6 9

7 SRr PRI JJ JLLP ~ VPNLt LLLLLLI LLN NI LS I I L I LLLLLSLLI LLRLLLLt LLLlSLMMSSLL t LI LLNRRNLLN NLLLI I I T JJJJJJ J JJJJJJJJJJLLLLI LLLI LLPMMKLM LLLLLLLLLSLLLLI LLLLLLLLLSMLMLMLI LLLLINRRLLLLLPLt LLI LLPPPR JJJ J J J J J J JJIXXIII LI LLLLI I NIIIXIItLLLLLLLLPXIIXLLLLLLLLLLLXIIIXPLL,LL,LI JJJJJJJJJJJJJXXZIIJJJJJJJJJJIIZXIXJJJYJJJJJJIXXZJJJJJJJJJJJXIIIIJJJJJJJJJJJIZXIJJJJJJJJJJJJJ LI PPIXXXI t L.LLLLI L.LPNP 2

+ +

NOZZLE ROWS

+ .NANMAY nmKEY FOWr UNIT 4

-+

TUBE RESTRICTIONS M3. OF TUBES FIGURE 7 GAUGING. }ISULTS-JULY, 1982 "-.S40 X PROBE None ~ ~ $ ~ ~

1

TABLE 4

. TURKEY POINT UNIT 4 JULY 1982 OUTAGE NMBER OF TUBES RESTRICTING PASSAGE OF PROBE LISTED S/G Probe Diameter Number of Restrictions A Inlet .700 - inch 46 A Outlet .700 - inch 3 B Inlet .700 - inch , 57

.650 - inch 21

.610 - inch 1

.540 - inch none B Outlet .700 - inch 13 C Inlet .700 - inch 28 C Outlet .700 - inch

~

~

Results of the profilometric inspection of the thirteen tubes in steam generator C selected on the basis of bulge-type signals d=-.ducted in the normal EC inspection zt the top of the tubesheet in the outl-'t leg were in:onclusive inasmuch as evidence of bulges (if present) could not be definitely established. Tubes R4-C1; R5-C1; R7-Cl; R9-C2; R10-C2; R33-C15; f.'.2-C41, 42, 55; R43-C32, 33, 34; and R44-C37 were the locations thus identified.

2.4 Review of Prior EC Data for R44-C57 R44-C58 Table 5 provides an independent analysis of the eddy current data from Steam Generator B, R44-C57, 58. These data encompass the period from the 1976 inspection to the present. Also included as Figures 10 and 11 are photographs of the oscillographic display of the eddy current signals. These data show incipient wall loss in 1977. The 1981 and 1982 photos indicate a strong tube distortion (bulge) influence at the point of tube penetration.

~~ ~

~ ~

~ ~ .'

e ~

~ ~ l er ~ 4~

~ ~

>> P

~ T l m p, ~

R>> ~. (a

~

rq ~

~ .l >> 'e' P ~

l Z

tl I ~

~

W l'Vl'cl s'4 ~ ol

~:g q'vi

~ C:.~

~ 1 PA >

~ L v'a'-'

~

FIGURE 8

'IURKEY POINI'NIT 4 RESULTS OF PROFILQKKY INSPECTION OF TUBE R44-C57, STEAM GENERATOR B, MZZ

~ l

~

~

~ 4 ~

~ ~

t

~

~

~

l

~ 87

~ ~

>> P ~

t 4 ~ ~

~ >>

~

~

C 4 o ~r'

.. g;,o ~

~

> I'(ta ~

~ ~ ~ . iP ~ w Qi t 4

r,'~ 0 pter+

')0 Fiflps V

gptr NCP A

rC~,

P

~ I'>>

g ~r.

>> p,rt

~ j P fl t

>> Q~

riv ~

~ -.t~!

~ri'2 FIGURE 9 TURKB'OINI'NIT4 RESULTS OF PROFILQKIRY INSPECTION-OF TUBE R44-C58, STEAM GYRATOR B, INLET

,r

~ ~

TABLE 5 EDDY CURRENT DATA ANALYSIS STEAM GENERATOR B ROM 44 COLUMNS 57 AND 58 J

Row 44 Column 57 Row 44 Column 58 April 1976 - Some distortion of the tubesheet, April 1976 - Same as R44-C57 but nothing to indicate loss-of-wall ot any denting or bulging.

May 1977 and April 1979 Change in distorted tubesheet signal May 1977 and April 1979 with. some indication of loss-of-wall - Same as R44-C57 at and above the top of the tubesheet.

May 1980 Signal starts in the direction of a May 1980 - Same as R44-C57 bulge (to right) but is rapidly drawn back to the left. This could be caused by loss of wall in that area.

July 1981 Complete saturation of the 400 Khz Duly 1981 - Same as R44-C57 f and the 400/100 Khz mix. No infor- 400 Khz and 400/1 mation available other than that mix. The 100 Khz there is a fairly large bulge. nal shows the pre However, the 100 Khz signal indi- of bulging but is cates 60 'percent - 80 percent torted by a verti loss-of-wall in that area. component probabl to loss of tubew Duly 1982 Same as above for 400 Khz and Duly 1982 - Same as R44-C57 400/100 Khz mix. Phase angle of 400/100 Khz mix.

100 Khz signal has rotated 100 Khz signal i further clockwise to the thru- at face value wo<

wall area, an I.D. indicati However, it is that the bulge (

b goes horizontall the right and th left) combined w O.D. loss-of-wal (which goes down then up) has ro a real 0.0. los wall into the I.

plane.

(<~) s:"D~r- ~'3 TUMZE POIhT t4

~ SI'EAM GENERA1QR 8 HL R44CSS R44C57 ~ ~ >>

V E I>>>>I' L.

i Q>>

A 4

5~- g

>>P >>

V ~ >>

~'

4/76

~ 6 I >>

5/77

~ ply d;

~ ~ /

~

J

R 44CSS R44CS7 V

I

~,

h l

4CW e

'p p-S/80

3.0 e

TUBE DAMAGE ASSESSMENT AND RECOMMENDED SAFEGUARDS Peripheral tubes in both the hot-and cold-legs of all ".h-,=e steam g-:.",erators have been examined visually from the secondary side using fiberoptics as well as EC probes through, the primary side. Additionally, profilometr~ was completed on selected tubes which appear to have bulges from the fiberscope examination. The following assessment of tube damage is based primarily on the results of visual examination and supplemented, where applicable, by EC' and profilometry data.

The major concern with tube damage on peripheral tubes is the potential of large leakage due to:

(1} Impact/wear damage to an active tube by a loose foreign object, and (2) Severance near the tubesheet of a structurally degraded plugged tube and its interaction with an active tube, resu1ting eventually in a large leak due to impact/wear damage.

Based on previoa~ s experience, a tube must undergo a significant (visible) structural degradation before it could precipitate any large leak due to either of the above failure paths. The logic to safeguard against any major tube failure is, therefore, to isolate the'ctive tube bundle from all structurally degraded tubes and loose foreign objects. The most positive a roach would be to physically remove all foreign objects and structurally approa unstable tubes if present (and/or segments thereof). However, another acceptable approach would be to create a picket, fence around all identified foreign objects and str ucturally degraded tubes along with a monitoring system to forewarn of any progression of damage through the picket fence towards the active bundle, so as to assure a safe and orderly plant shutdown for any corrective action.

P

~ g I

The sentinel plug concept* fs recommended for use fn tubes forming the picket fence. Sfnce the observed tube damage fs prfmarfly to the peripheral tubes and the faf1ure paths for a potentfal large leak are also associated mainly with these tubes, the sentinel plugs are approprfate next to the damaged perfpheral tubes only. Any other areas of concern are recommended to be picket fenced vfth conventional (mechanfcal) plugs.

'Table 6 surmarfzes the tube damage assessment and recomnended picket tubes with sentinel plugs.

• Sentinel plugs are standard mechanical plugs with a small, built-fn leak path, fnstalled fn the unit into the inlet side of tubes not known to be damaged but located adjacent to tubes where for efgn objects were wedged, or where known tube damage had been established. The purpose of 'these plugs fs to provide early warning in the form of controlled leakage of about 0.15

,gallon per minute, fn the unlikely event of a damaged peripheral tube severfng at the tubesheet,and damaging the neighboring tube plugged wfth the sentinel plug through impact/wear interaction, resu1ting fn a through-wall penetration of the sentinel fence.

I w

s TABLE 6 TURKEY POINT UNIT NO. 4 STEAM GENERATOR:S

SUMMARY

OF TUBE DAMAGE ASSESSMENT AND RECOMMENDED S" 35j'INEL PLUGGING+

,/

5/G-A Tubes R43-C32, R44-C35: .Local wear marks near tubesheet due to loose weld rod: wear pattern about 3/8" long axially and deepest penetration may be approaching through-wall. Both tubes are structurally stable and were previously p1ugged.

Sentinels: R44-C36, R43-C33-36, .R42-C33 (6 total).

2. 5/G-8 Tubes R45-C54: . Locally indented over 3/8 to I/2" near tubesheet R44-C55-58: Locally bulged near tubesheet, axial length, about 1/4",

maximum bul ge "30 mils. (Profilometry on R44-C57-58 shows bulges to over 60 to.120 degrees around circumference with maximum bulge 'xtend size of 25 mils.)

R45-C53, R43-C59-61: show polishing, peening and small ding marks.

All tubes are structurally stable and with the exception of R44-C57-.58, all were pr eviously plugged.

Sentinels: R43-C54-58. (5 total)

3. 5/G-C Tubes R45-C51-54, R44-C55: Indented locally due to Impacting by a loose pin; damage somewhat more severe than R45-C54 in S/G-B, with possible thru-wall penetrations on R45-C52 and 53.

All tubes are structurally stable and were previously plugged.

Sentinel s: R44-C50-52, R44-C54 (4 total)

• Fence is completed'by tubes plugged in previous outages and additional neighboring tubes plugged conventionally at the present outage. Tube R44-C57 fn S/G-B was a leaker and was plugged conventionally.

o i ~

~

6~ ~

4.0 SAFETY EYALUATIOM 4.1 Continued 0 eration.with Forei n Objects Present in Steam Generators I

.All three steam generators have been visually inspected on the secondary side utilizing fiber optic techniques. These techniques allow the fnspection of the entire periphery of the tube bundle. The inspection results have cataloged and located observable foreign objects around the periphery of the steam generators. These objects as well as observable tube damage have been documented with photographs. All loose objects have been removed. Three small foreign objects still remain wedged between tubes in the bundle. On the basis of their apparent mass, these objects have been assessed as presenting no potential for tube damage in the event they may become dislodged. An eddy current inspection has been performed around the wedged foreign objects to determine the condition of the tubes adjacent to foreign objects. A review of previous EC inspection tapes has been performed to attempt to determine if

, C wedged foreign objects are in fact wedged and have been in their present locations S Y for a period of time.

~ ~ ~

The following actions were taken to assure the integrity of the steam generator tubes during the next period of operation: (a) A conservative tube plugging program including preventive plugging and the use of sentinel plugs was developed during the foreign object retrieval operations as a contingency position in the event that the larger, more significant of these objects could not be removed. As the r'etrieval efforts continued, all of the significant objects were successfully removed. However, the planned plugging program has been implemented in full to maintain conservatism. All the tubes surrounding the wedged foreign objects have been plugged and sentinel plugs have been installed a~ound potentially degraded tubes. Sentinel plugs are standar d mechanical plugs with a small leak path built into the plug. The sentinel I

plug will alert the operator iri the'nlikely event that a tube adjacent to potentially degraded tube'as started to leak, will limit the postulated leak and will allow the plant to respond to the situation in a normal controlled manner, (b) A met'al impact monitoring system has been installed on the secondary side of each steam generator as a means of detecting wedged foreign objects which may become dislodged or any additional foreign objects which may

g 4

~ 0 intrude into the steam generators. The detection of significant'mpacts will allow the plant to undergo an orderly shutdown for steam germ.'.;- inspection.

The proposed period of operation for the unit is until approximately mid-October 1982 at which time it is planned to shut down for steam generator replace.':ent.

Completion of the above actions and the short operating interval allow operation of this plant with known foreign objects in the steam generator without presenting undue risk to the health and safety of the public.

4.2 ~Tb P1 ggi As a result of the eddy current and visual inspections, a number of tubes were plugged for various reasons. In each steam generator, several tubes were considered to be pluggable due to their proximity to observed foreign objects, the presence of a bulge in the tubes, or both. Additionally, in Steam Generator 8, the leaker (R44-C57),an adjacent tube with a 56 percent eddy current indication {R44-C54), and three tubes with restrictions at the tube support p'fates were designated for p'iugging. In the case of the restricted tubes, one was a 0.610 inch restriction, a size which had been plugged in earlier inspections in this unit, and the others were 0.650 inch restrictions, plugged conservatively because of their peripheral locations.

Sentinel plugs were installed into fifteen of the tubes, as described in ti on 0

Sec 3. 0 above.

The location of the tubes plugged is shown in Figures 12, 13, and 14 for Steam Generators A, B, and C respectively.

A list of the tubes plugged, including the location of the sentinel plugs, is given in Table 7.

33 63 9/74p TUBES PLUGGED 6/7Sp TUBES PLUGGED ' I 169 86 2/78p TUIIFD 8/78p TUBES PLUGGED PLUGGED 1 DATE HOT KHOMMp TUBES PLUGGED K 2

~

~ StIOP MELD, HL ttISDRILLED SERVERS 1 StIOP MELD L 79 4/794 TUBES PLUGGED 2 S/764 TUBCS PLUGGED 92 131 11/764 TUBES PLUGGED 7/77'UBES P1.UGGED N

N P

72 27 36 S/8BI HECH PLUGGCD 11/89l tICCH PLUGGED 11/81IHECH PLUGGED FL'A-A I 7/77'ELD REPAIR HL, E/P CL COLUMNS 0 XMH XXO 0

tt MO 00 XOXX 000 0 00 OJ HHH HHH HH'M X

X P

PXXOKKOXXOX0 XC PN IQkxt JO XOQH

~gZR 0 eeoo XXXI-IGGGQM0 XXCJHO 000 OO 0 OOX 42 41 38 4~

43 39 XXX 00 nx 37 ZXO XCC 36 0 000 34 00 0000 33 0

0 A 0 0 32 31 0 P A 0 38 A'00 XO 00 00 0 Ith A AAAAhh PAAA AA - 00 28 27 00 00 A

I h 00 00 26 25 0 A 0 24 22 23 00 00 XZ 0

0 00 0

ZO 889 L059PA e

ISB PNPP PNNP 00'0 0

0 t4HN t4P H NNN 21 19'S JJJ JJJJ el)BII8 PNNPLLLMP NXXJl t40 JJJJJ ~ I GQL ~ 0 14 OOJJJJJ 0% JJJJ lt8 N XCCCOO LCCOPO 12 Llt4NJJJJ poeoop 18 ONN JJJJ PPP N eoe QGNGGOP OX 0

JJJJ LJJJ 8 H P 8 t4H BEHJ JG JLJJM PPHMH JM 9 LJHH HH P NLLL8 XX QQO GPGNQGQO XGOHMHQQO 8 0 I II J LILMH HtHH LLXX JJJHI PP+5 LXLJL I 0 IQPOOHHQO 6 0 LJLLLJ MLJXLH 5IHHXX 5JLOQX H XX ILX95HI bLXXXX OXOJJL XLL OIQOLOHH 0 0 LJJXJl LJHHIb LZXZMHMZZXZXbtLLXXXX ZXIQQ OXXXX JLL t 5595Xbbeeo J JL XXXLL 00000000 H 4 PL JJJZJI-L LJZZXZ L8XZX JMHXXIIX XXxXZGL XXIQQNQIZZZIZ~MIXIZBXZQOJJ8 xxxJL oeoooeoooip XXOXXXILXXXQXQIXIIXXOIZXXXGOOZOIXGXZXLLXIXXXXXIOOQQOOOIIIOLLOOQGGQOOOQIL LLLZJJJZJLLLLLJIZXXLFFFFFFFFFFFFFFFFFFFFFFFFFfFFFFFFFFFFFFFFFFFFFFFfFFFFFFFFFFFFFFFFFFFFFFFF 2 3 FFFFFFFFFFFFFFFFFPFF +

+- MANMAY ROWS NOZZLE FIGURE 12

'IURKLY POINT UNIT 4 SKAM GENERA1QR A JULY, 1982 OUTAGE REC{BKNDED PLUGGING

t

'12 TU:-ES PLUGGED.PRZOtt TO 10/75 i'

'I II 0 10/77'UBES PLUGGED C 0/7st BAIZE HOLE PLUG HL E/P CL H 70 2/78g 'TUBES PLUGGED E,

F' SHC> VELD 0/. Sp BIRC HOLE PLUGS HL,CL P 28 8/70 TUBES PLUGGED SERZES 44 3

1 R 52, 8/79'IUBCS PI.UGGED G/75< TUBES PLUGGED I 45 0/75'UBES PLUGGED S 48 5/80< HECK PLUGGED st K

L QQ SC4 I

Il/.dg TUBES PLUGGED 7/77/ LIELD REPAIR 7/77'IUSES PI.UGGED T

U Y

Sd 12 5

'll/00s t<ECK PI.UGGCD II/BtgKECK PLUGGED I I/Ol gtt/P. tlL OIILY 0/02t tIECII PLUGGED FLA-B M

0)

Q Q 6)

N LO N Q) 00 Q & lA le S N lO 0) 0) N lo R Q N lA lIr} Q > lA R 0) N N N S N N N N N (0 Q Q Q Q S lA lO N ID V < V < V 0) Ff 6) 0) N Ol N 0l M (V 0) W U) N 0 N U) (9 COLUWXS. t m

60 etpL zim R)00 I'I }

}

<iNmmmlss

} }

Num!m<Nm[mm<!<<mmmm e etc e e n! m m n m <- C e C ~ n n m n N mme'Nc>mmwzasmmq N < ~

s s

s II NNN ONNN UN Nt<U

~LL TN SNN CCI 0 0

OTO AAAA A A A A

R VT ssn AS S

U AUA GUNN VORRTUNO NL 'NW AAA L OL<

PS'M WA 0

000 ONO ON 0 NNO SU 00 LI I

~ LLL

~36

~ -}

-34 Pa 4 43 38 39 37

'I

} ULLLO 0+NNR A AA A s AA UUU 0 - s 32 Opt <Rg~

T,

~

A ~ s NNR A A L A AAAA oooo

! A A

~A A A A I AA AA

+-' ~t -- 29

t. P8

)t}fb

~ I

}.00NV NNN s

A I-J A'TT AAAAA AAAAA AAAH "I

00 I<IOO 0

vo '~.

T 26 27 24 33

}-.'.

I HTAT

~~

S NQ t' oM 2<

~~

NO AA A <<I

.+- .I-}

~+ JPt. t Q sss l9 t<R s s.. A

}<<~ s's

-4/sss~

~

~

~f A<

No U l 8 ou - TV~

'T A SSV ) 7 4 ~

s N 'I.r~~ s 1 IA TTUV+AA l6 lS .I

~A . qJ...

AA

,nB: WTUUULS,,

4A4LLL',

l2 f3

<01LP? J )- A T < RLLNLO CQ PP?

0< TPP?s pfLLoA

0 l TRRRT

PNN ~

A A '

't-A L AST;T TT TA U UL.LNNOO LI-LLLT 0 RRLI RI I I 1 I l8 g ~ I, q ATAA

<<<<SLAT~

Oo AT 1 RARRLL

~ T

. TTT < S JTTLI A A,~ Nt AR RL A

A ALLNATT T } S I LLI LNRAALL S RARAAL <<LPLL U TN I I t Lt ALLLNP S t NI AS LLLLILLLL LL I.)

AAL S LI LLLS S

LI LLLR S V LLLLLLR SLAV U

'T E TLL U

LLLP U L

SLLLLRU TL ALI NLLI I-I NLLLLIL LLLl I 'T RLI LLLLLRO NLLLLL LLO 0

0 8

6 7

~ ~

~ ~

~

SA ~ PRL JJQLLP ~ L<PNLLt Lt LLLLLI NI NLI S Lt LLLLLLLSLLLLLALLLLLLLL} SLHHSSLLLI LLI NRANLLN Nt.l I I I I 4 J J J J J J J J J J J J J J J JL'LLLL Lt LLLLPHH<s:LH LLLLLII LLSLLLLLLLLLLLLLI SHLHLHSLLLLLLLNRRLLLLLPLLLILI PPPR t-LLLI LPPXXXXLLLIt,'.LLLPNP I

J JJ J J J J J J J J J JZXXZZLLLLLLILLNZZXXXXLLLLLLLLLPXIXXLLLLLLLLLLLIIXIIPLl JJJJJJJJJJJJJZIZZXJJJJJJJJJJZXXZXXJJJVJJJJJJIXXXJJJJJJJJJJJIXXIXJJJJJJJJJJJXXXXJJJJ.jJgJJJJJJ 2

+ +

+- .NANMAY

'IU}KEY POINT I/IT RECV+KNDED PLUGGING NOZZt E -+ RQMS - I I

s

<l FIGURE U

. SIEAM QENgN'mR 8 JULY; '1982 OUTAGE X LYING mOE (1> . oss 8 PREVENI'IVE PJ.UGGING DUE TO FOREIG<N.OH THCI'20)

~ ~

}

o PREVENTIVE PLUGGING ~@PM'NDlCATION (1)

~

o pREvrNI'IYE pllJGGING PR }

4 Q ~

I I I II I I II I I ~ t ~ t ~

0 II t ~

0 li ~ ~ ~ 0 II ~ ~

0 Ii ~ ~ 0 II I ~ 0 II ~ ~ 0 II ~ ~ 0 I~ ~ ~

~ I II I~ I ~ I I I I ~ ~ I I

~ .... . Ilkkas

~ ~

ii Wk WWWL'LWRLWWWWW5 SSNWWNW!

r Wgkkk~!)Sikkim iiiii WWSWWWWWWWWSWWWklkk kiiiiikkkikkkkkik Wk!BNH Nikiiiik N, hlL~SWNSNSSSNLNW 5WWNNNSW kikkikik SiikNNNW y

"'"al"" '8""8 I"'I"8I'0""

5OWWNSNSNNWWW

~

Wkik NEWSkiiiiiiii

~

Nkiii WWN NW WSWNWWSWRSg . SWNWWWW SNNWSNSWW Wkgkkkkkk W 55

'.,"',. Nkuqkrkkkkkkk

..'ik WWWNWWNWW CNWWWNWNWWW NNSNWSNkggkkkkk Wkk NWNWWWNW/gkkkkkkkk kikiikik WSWWWWSWS WNWWSWWN WNS~WNNN1TWSSNW .

Siiiiiiiirkrkkkiik WWNWNNWSW NWWWS S ~

SSWNNNNNW NNSNSSS

.."..'h5'"""'NNNWWNS'5llS~PIWNSW5LLWWWNHSN~SPNiSNIEPSS~PIEPN

~ ikiiiiii 5~4~4SSWSNNW

~ ~

'..SOSSWRW

~

Wikkii WWWWWWWWW WWWWWWWWWWWN WWWWWW WWWWWWWW NiiikkkS Wkikikik Wiiikiii WWWWWWWWC NNWNWWWN

~ ~ Sii )WWWWWWW1 WWW WWW5 Wkgkkkkkk WWWWNN WWWN Wfk W W 'kkf WWWW55NWW! WWWWWWNN

)NQWWNN/

5SNW5NSN885kkrWNWWHHI5SWWERWWWSSWN Wkkkk555 WNNWNWNN SSNSNWSN iikiikik gg NSNNN W)55 WN5 NWNSWWWWN

~ WNWNWW WNWW WWWW

~WNSW%% WWWWSSW/W QKQSNWS5S55NS1WWR$ 5

~

Nhkkkk NLlkki NS)NW iiiik WWWWW5 WWWWS Wii iik SNW NWWNSNW 5WWWSNNW WWWWSSWW Wikikkki Wikiiiik NniS ht%S WWSW1kkktS NS5WWS WWP4W NF4NWNW/ WQWWWSN S

%%WWNWWN QWNNSWSWNWWWWNNWN Nk WSWWN W

Wi, Ni

~,Sg ikik WWS)WS, QWW Wk W

SISS W, NWWN5 5NWW

. Si k S,, iLNikk WWEW

!NNSSWNW

)WNNN)

WSW W NW,',

W LNSWWW5kg SSRSWSWSS5 ggkggSSNSWNS 55WRRSSgkgk WNWNSWWak5N

.. NE M

Wi

~ )k N i k

~ l >

j I

I

~ k g k 4 II I ) Ql ~

'e I

J

~

I

~ i ~ ~

TABLE 7 TURKEY POINT UNIT 4 JULY 1982 OUTAGE RECOMHEhDED TUBE PLUGGING The following tubes are recomnended for plugging:

Steam Generator'A": (6 tubes)

Preventive Plugging due to proximity to foreign objects:

R42 - C33*

R43 -. C33*, 34*, 35*, 36*

R44 - C36*

Steam Generator "B ": (25 tubes)

Preventive Plugging due to proximity to foreign objects:

R41 - C30, 31, 32, 33 R42 - C31, 32, 33, 34, 35 R43 - C32, 33, 34, 54*, 55*, 56*, 57*, 58*

R44 - C51, 58 R45 - C53 llkBL T b:

R44 - C57 Pluggin for Eddy Current Indications:

R44 - C54 (56 percent)

(*) Denotes sentinel plugs installed on the inlet side, normal plug to be installed on the outlet side of the designated tubes.

~

~1 ~

RECONEISED TUBE PLVGG1NG Preventive Plu in for Restrictions:

R9-C91 R25 -

- C67 Clo'R40 Steam Generator "C": {43 tubes)

Preventive Plugging due to presence of tube bulges or proximity to foreign objects:

R3- C 2 R4- C1,2 R 5- C1,2 R- C 1 7R- C 2 R10- C2,3 R11 '- C 2 R32- C15, 16 R33- C15, 16 R41- C41, 42, 43, 54, 55, 56 R42- C41,.42, 43, 54, 55, 56 R43- C32, 33, 34, 35, 41; 42, 43, 53, 54, 55, 56 C37, 48, 50*, 51*, 52*, 54>>

'I

(*) Denotes sentinel plugs installed on the inlet side, normal plugs to be installed on the outlet side of the designated tubes.

II ~

APPENDIX 1 Foreign Object. Retrieval Operations Performed in Secondary Side of Turkey Point Unit No. 4 Steam Generators July, 19".?. Outage The techniques used in retrieving the objects required the use of electro-magnets, horseshoe magnets, grabbers, electricians snake and a special tool used to move objects'out into the annulus from between the tubes. The special tool sends a piece of banding material down the tube lane and bends it 90 to go between the tubes and ease the objects into the annulus.

Extreme care was taken when pushing the objects into the annulus to prevent damage to the tube bundle. There is usually no contact with the tubes when retrieving objects in the annulus. tlost of the retrieval tools are wrapped with heat shrink tubing to prevent scratching tubes.

APPENDIX 2 UNIT 4 STEAM GENERATOR LOOSE PARTS MONITOR.

DISCUSSIOH:

the steam generator MIM system is a 6 chan" 1 system. Each channel

'consists of' detector, a 932 Amplifier Module and a 1432 XmpactDetector Module. The 6 channels feed a 1433P Contxol Module and a 143'3C Audio

'onitor. A system alarm 9.s indicated on th 133A alarm module and 'on Annunciator Panel G where the alarm 9.s combined with the Reactor Vessel Metal Impact Alarm.

Each 932 Amp19.fier module has two controls. One sets the low pass filter upper frequency limit. It 9s normally set at 50KHZ and should not xequire any reset'ting. The second switch determines the amplifier gain-Xt 9.s set at a value of 50 and should not r qu9re adjustment. Higher settings will overload the amplifier as indicated ww>> .by the amplifier monitor light turn-ing from green to xed. A lower setting reduce gain and system sensitivity.

An excessive number of spurious system ala.m can be reduced by lowering the gain setting. Xt should however,remain at z value of at le'ast 20. Xf the gain is adjusted to reduce the number of spurious .alarms I & C should be notified.

The 1432 Impact Detector modules have no front panel adjustments. 'he module uses a filter arrangement to establ'sh a reference background noise s9.gnal, it then looks for a transient noise signal at. a given level above background. When this occurs, a channel a'zrt will occur and be indicated by a red light on the 1432 module.

The 1433P control module is activated when zny of the six impact channels gives an alert. The control module will display the number of the first channel that s9.gnals an alert. Xt will also start a timed counter. If 5 channel alerts on a given module'occ'ur i" a 10 second period, a system alarm will occur. If 5 alerts in 10 seconcs are not detected, then the system will automat9.cally reset. The modu e has two controls. The alarm reset switch is used to reset a system alam. It must be'epressed to clear the system after an alarm condition hzs occurred. The second switch is the Auto Reset Per9.od,Switch. It is no~lly in the enable position.

5ihen placed in disable, it eliminates the 0 second time period requirement for a system alarm.

The 133 Alarm module has a red indicator light that indicates a system alarm and an alarm test push button. l I

The 1433 C Audio Monitor module has a'peake='nd a selector switch that can be used to monitor the audio on any one of the six channels. All other controls are used for an. internal test simulator and should not be used for normal system operat9.on.

A listing of channel numbers and detector locations is attached as enclosure (1) . The system sensitivity 9.s set so that it will detect a 0.048 ft-lbf impact 1 foot from the detector. Because of this high value of sensitivity alarms can be expected during any evolut9.o" which changes the status of the plant. An actual metal impact will be a ve~ loud metalic clank on the audio speaker.

4 STEAM GENERATOR LOOSE PARTS MONITOR DETECTOR LOCATION Channel Number Location 1432 Module Label 4A S/G Lo~er Level Tap 4A S/G Tube Sheet Drain 4B S/G Lower Level Tap 4B S/G Tube Sheet Drain BB 5 4C S/G Lower Level Tap 4C S/G Tube Sheet Drain CC Enclosure (1)

r ev ~,

C