ML19093B033

Enclosed Justification for Tube Inspection Program & Plugging Criteria, Results of Completed Surry Unit No. 1 Inspection Program with Small Change in Denting

ML19093B033
Person / Time
Site:	Surry
Issue date:	11/30/1977
From:	Stallings C Virginia Electric & Power Co (VEPCO)
To:	Case E, Reid R Office of Nuclear Reactor Regulation
References
Serial No. 486A
Download: ML19093B033 (28)

Text

{{#Wiki_filter:RICHMOND,VIRGINIA 23261 November 30, 1977 : Mr. Edson G. Case Acting Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission

• Washington, D. C.

20555 Attention: Mr. Robert W. Reid, Chief Operating Reactors Branch 4

Dear Mr. Case:

Serial No. 48 PO&M/TAP: dgt Docket No. 50-280 License No. DPR-,32 The results of a recently completed. Surry Unit No. 1 inspection program are presented in the attachment to this letter. Although the results are sim-ilar to previous Surry inspection programs, it is noteworthy that the rate of progression of. the dented r_egion boundary seems to have decreased to less than the previously predicted rate. This fact is reflected in the plugging criteria which is described and analyzed in the attachment. The total number of tubes plugged in Surry Unit No. 1 is approximately 20.8% which shows a small change *in denting since the last inspection. There-fore, analyses r_egarding safe operation under normal and accident conditions are applicable. Therefore, we request that Surry Unit No. 1 be permitted to operate as follows:

1.

Unit No. 1 shall be brought to the cold shutdown con-dition in order to perform an inspection of the steam generators within six equivalent months of operation. Nuclear Regulatory Commission approval shall be obtained before resuming power operation following this inspection. For purposes of this requirement, equivalent operation is defined as operation with a primary coolant temperature greater than 350 degrees F.

2.

Primary to secondary leakage through the steam generator tubes shall be limited to 0.3 gpm per steam generator. With any steam generator tube.leakage great.er than this limit the reactor shall be brought to the cold shutdown condition within 24 hours. The leaking tube(s) shall be evaluated and plugged prior to resuming power operation.

3.

If the primary to secondary leakage limit of 0.3 gpm per steam generator is exceeded more than twice in any 20 day period, Nuclear Regulatory Commission approval will be ob-tained before resuming reactor operation. 77:::~4015:.:: 1

e e VIRGINIA ELECTRIC AND POWER COMPANY TO Mr. Edson G. Case Page No. 2

4.

The concentration of radioiodine in the primary coolant shall be limited to 1 microcurie/gram dose equivalent I-131 during normal operation and to 10 microcurie/gram dose equivalent 1-131 during power transients. We believe the operation of Surry Unit No. 1 as described above will in no way endanger the health and safety of the general public. Attachment cc: Mr. J. P. 0 'Reilly Vi;~Y trnl.'-yours,,j I u~u.)v&;;,/ 11

• ~

C. M. Stallings~ Vice President-Power Su~ply and Production Operations

e e

1.

Inspection Program JUSTIFICATION FOR TUBE INSPECTION PROGRAM AND PLUGGING CRITERIA Page 1 of 11 The tube gauging program used for this inspection of the Surry 1 steam generators is primarily based on the results of finite element analysis. Only in local regions of the plate, such as patch plate and wedge loca-tions, is data from previous inspections heavily relied on to formulate the inspection program. Figure 1 illustrates the sequence of computer runs to current operation and for approximately 6 months of additional .operation. The tube inspection program is conservatively defined by the 12,5% strain contours from the computer run which yields tube hoo.p strains at the current time (approximately 6.0 months beyond full flow slot closure). The results of this computer run are shown in Figure 2(a). The inspection program outlined in Figure 3 includes all regions containing strains in excess of 12.5%. Several of these regions are discrete zones bounded by 12.5% strain contours, but not exhibiting 15% strain contours. The objective of inspecting these regions is to confirm that tubes with strains less than 15% are not subject to excessive tube restrictions and hence are not vulnerable to Stress Corrosion Cracking. This will be dis-cussed further in a later section. Additional conservative inspection Lriteria have been used for this outage as in previous outages: (a) Gauging extendeq for at least two rows beyond any tube that did not pass a 0.650" probe in the tubelane region. (b) Gauging was done for the wedge regions as outlined in Figure

3.

The inspection continued for two rows beyond any tube which did not pass a 0.650" probe.

e Page 2 of ll (c) Gauging for the patch plate is as outlined in Figure 3. The inspection continued for two rows beyond any tube which does not.pass a., 0:.- 650" probe. The entire inspection program for the hotleg is shown in Figure 3. The strain map shown in Figure 2a indicates regions of strain in excess of 15% on the coldleg side. During previous inspections, the cold leg regions were covered by the U-bend inspection program conducted from the cold leg. _With the occurrence of one leaking tube in S/G 'A' and the indicated ex-pansion of strain contours in the cold leg, the inspection program was expanded for S/G '_A' coldleg and is identified in Figure 4. Based ori pre-vious information, degradation of 'A' S/G has always preceeded Band C by at least six months; therefore, cold leg inspection of Band C will be*Jone during the next scheduled outage. 2, Plugging Criteria (Based on this and previous inspections) The plugging criteria used to formulate the current plugging pattern at -Surry 1 is similar to that applied at the previous Surry outages. The addi-tional information obtained from each reinspection has strengthed the confi-dence in the current plugging criteria. The factors leading to this in-creased confidence are: (a) Location of recent leakers (since 3/77) in the tubelane region. The leakers are plotted on the appropriate strain contour map in Figure 5. They show that the tube hoop strains in every one of these tubes exceed 15%. The hoop strains in tubes in the patch plate and wedge regions, which have leaked, are believed to be as

high, However, since these strains are caused by very local plate conditions, they cannot be represented by the finite ele-ment results.

Page 3 of 11 e e (b) Gauging results which have indicated that tubes with through wall Stress Corrosion Cracks in the tubelane.region are de-formed to the extent that they usually cannot pass 0.470" probes, and, with two except ions, can nev 0er pass O. 540 II probes. (c) Progression of restrictions in the tube1ane region in those tubes were significantly restricted (unab:le to pass 0.650" probes or in areas of high strain contours and adjacent to severely restricted tubes) in previous mspections. Table 1 lists the number of tubes at both Surry 1.and 2 that previously restricted the 0.650" probe and the numb.er that restricts the

o. 650", o. 610", and 0. 540". probe at the :most recent outages (this amounts to an operating period. of almosit. f6 months for each unit).

A significant number of these tubes sti11 ;pass the 0.610 inch probe indicating a maximum reduction of ~O mils in 6 months if the conservative* assumption is made that: \\they all had O. 650" minimum diameters at the previous outagem There is every reason to believe that among all the tubes not passing a 0.650" probe, but passing a O. 610" probe there is close.to ii uniform distribu-tion of minimum diameters. Further, it ~s reasonable to assume that the tubes that still pass 0.610" prdbes were those with the larger minimum diameters at the previi!ous outages. The re-maining tubes (considerably less than~[ of the population) could reasonably be expected to have been at minimum diameters below 0.6301(0.650 2 +.610l Likewise, tihe tubes that are now in the population that restricts a O. 610_ poobe are more likely to have minimum diameters above 0.575,(0.6ll.J0; 0.540l Thus, a con-servative decrease in diameter for these itubes is 0.630-0.575 = 55 mils. Finally, the few tubes which cannot now pass the 0.540" probe .G.. . ]!

e

• Page 4 of 11 (20 of the 347 previously restricting the 0.650" probe) would be those that barely passed the 0.610" probe previously and now are just below a 0.540 diameter.

Using 0.620" and 0.530", the mean decrease in diameter is: 0.620 ~ 0,530 = 90 mils 'While this is a probabilistic argument,. it should be pointed.out that at least 70% of the tubes have.definitely had their diameter reduced by less than 40 mils in 6 months, giving considerable credance to the manner in which the diameter reduction has beeh calculated for the remaining tubes, and indicating a low probabil-ity that a given tube will suffer a diameter reduction of greater than 40 mils in 6 months. Thus, plugging of tubes which cannot pass 0.610" probes is still seen as a rather conservative measure for the following reasons: (a) It is unlikely that a tube will suffer E diameter reduction of greater than 70 mils, thereby causing it to restrict O. 540" probes. I (b) With few exceptions, tubes in the tubelane region do not suffer thru-wall cracks until their minimum diameter is somewhat less than 0.540". This is supported by the fact that all but two of

• the leakers in the tubelane region have restricted the 0.540" probe and many tubes (including those preventatively plugged at the first inspection programs) had restricted the 0.540" probe for some time and still not leaked.

(c) Most of the tubes that do pass the 0.610" probe have minimum diameters in excess of 0.610". ...:t: ?* ~'. . }~

e Page 5 of,11 The inspection results indicate that while there is no alternative to plugging tubes inward of those restricted by the 0.610" and 0.540" probe, it does appear to be conservative to plug outward from tubes which re-strict the O. 540" probe thereby including tubes which restrict only the

0. 650 11 probe and in many cases do not even restrict that probe. However, we will continue to plug on that basis but now feel confident that the growth of the 17.5% contour is a more appropriate measure of movement of the severely dented tubes.

Based on the tube hoop strain plots shown in Figure 2, the growth of contours which are representative of the strains, that exist at Stress Corrosion Cracks is approximately 1/3 tube row per month over most of the tubelane, and 5/6 row per. month at the outside

columns, This is displayed graphically in Figure 6, and further con-firmed by the locations of any tubes restricting 0.540" probes at this time.

This later point will be discussed in the next section, The same*growth rates hold for the cold leg side of the bundle with the exception of the outside columns where the growth is lower than 2/3 row per month. This is also displayed on Figure 6. The basis for the plugging criteria still uses the occurrence of tubes that cannot pass 0.540" probes. Based on the growth rate of high strain regions, each additional row beyond a tube which cannot pass a 0.540 11 probe affords 3 months of operation over most of the bundle, and 1.2 and 1.5 months of operation at the outside columns of the hotleg and coldleg respectively. Again, there appears to be a good argument that the majority of tubes which cannot pass the 0.610" probe but can pass the 0.540" probe can sustain oper-ation for 6 month periods. This will be further studied at future outages. At this time, all tubes restricting the 0.610" probe will be plugged. Further, while there is still no evidence that plugging based on a pyramiding

e e Page 6 of 11 effect is necessary, it appears prudent at this time to apply good engi-neering judgement and selectively plug certain *tubes in a given column which are surrounded by tubes exhibiting high levels of deformation act-ivity. Finally, due to the local plate cracking which is believed to occur at the periphery near wedge locations, tube leaks can occur here at levels of tube restriction (tubes restricting only the 0.650" probe) less than in the tubelane'region. This phenomenon is similar to that which occurred at the patch plate, thus the plugging criteria at the wedge locations calls for plugging leakers, tubes that restrict the 0. 540".and O. 610" probes, and peripheral tubes that restrict the 0.650" probe. In addition, tubes surrounding leakers and those that restrict the 0.540" probe will be plugged. The complete plugging criteria which supports at least six months of opera-tion are: (a) All tubes which do not pass the 0.540" probe will be plugged. (b) Additionally, for in excess of six months operation, two tubes beyond (i.e., higher row numbers) any tube in columns 15-79 which does not pass th*e 0,540" probe will be plugged; for such tubes in column 1-14 and 80-94 five tubes beyond will be plugged on the hotleg side and four tubes beyond will be plugged on the coldleg side. (c) All tubes whicl:1 do not pass the 0.610" probe will be plugged. (d) The tubes in any column for which plugging under criteria (a), (b), or (c) above is implemented will also be plugged in the lower row numbered tubes back to the tubelane if not already plugged.

/.

e . Page 7 of 11 (e) As a conservative measure, tubes completely surrounding any known leaky tubes *including the diagonally next tube -- will be plugged, if not already covered by the foregoing criteria. {f) In any_given column which is surrounded by columns containing tubes with significant tube restriction or prior plugging, (there-by creating a "plugging valley" in th~ pattern) engineering judg-,- ment will be used to fill the bottom of.the valley. In the peri-pheral tubelane areas near the three.and nine o'clock wedges, tubes surrounded by previously plugged. tubes or tubes e~hibiting high deformation activity will be plugged based on engineering judg-ment. {g) Additional preventive plugging will be implemented at the wedge locations. This plugging will include all tubes that: (:t) restrict the 0.540" probe (2) restrj,ct the 0.610" probe (3) restrict the 0.650" probe at the periphery (4) sµrround leakers and tubes that reitrict the 0.540" probe -- including the diagonally next tube.

3.

Evaluation of Inspection Results The results of the inspection program as specified above and outlined in Figures 3 and 4 are presented in Figures 9 through 11. Several significant facts are worthy of further discussion: (a) After six months of operation, and at a stage of the denting phenomena well beyond full flow slot closure, only three tubes have leake~ within the normal inspection program. One addition-al tube leaked from the coldleg side and subsequent gauging in-dicated that some measure of inspection was required on the coldleg side, of 'A' S/G. ~..

e Page 8 of 11 (b) Only three tubes on the hotleg side restricted the 0.540" probe, further highlighting the effectiveness of the preventive plugging program instituted in April. All but two of the tubes that restrict 0.540's on the coldleg side lie outside of row 5 and thus were never gauged before. However, they all lie in the peripheral columns, fall within the 15% strain contours, and are clustered to~ gether. Thus, they would certainly have been gauged were a cold-leg program instituted previously and quite possibly all would have been plugged. They are compatible with the hotleg history and the finite element results, and the coldleg will_ be suitably moni-tored at future inspections. Further, a plugging-criteria has been established for coldleg tub.es consistent with the finite element results and the hotleg plugging criteria. (c) All tubes which restrict the 0.610" probe on the hotleg side lie adjacent to* previou_sly preventatively plugged tubes and well with-in the 15% strain contour. All the tubes which restrict the 0.610" probe on the coldleg side lie well within regions of high tube strain.contours ind~cating a coldleg denting progression similar to the hotleg progression but at a reduced rate. (d) Of all the tubes at Surry 1 that restricted 0.650" probes at both the previous and current outages, 60% still pass the 0.610" probe and more than 98% still pass the 0.540" probe. Again, all of these tubes lie well within the 15% strain contours. (e) No tubes restrict the 0.650" probe in all the discrete zones bounded by 12.5% strain contours, but not exhibiting 15% strain contours. (f) No restrictions occurred in the wedge or patch plate regions. . /

e e Page 9 of* 11 (g) In no case where there is a so-called "spiked" preventative plugging pattern has there been any significant restriction of tubes in the adjacent columns. However, in regions of the tube-lane where*a given column is surrounded by columns with signifi-cant plugging and tube restriction, thereby creating a "valley" in the pattern, some increase in tube deformation has been ob-served at the bottom of the valleys. The conclusions which can be drawn from the eva-luation of the inspection results are: (a) The recent gauging programs and the related plugging criteria have been extremely effective in preventing leaks and have also been extremely effective in minimizing tubes at potentially high tube strains over the entire operating period from outage to outage. (b) The tube strain coptours developed with the aid of finite ele-ment structural analysis have been remarkably effective in pre-dicting trends in tube bundle behavior. (c) It may be necessary at future inspections to probe tubes on the coldleg side of the bundle to the extent dictated by the tube strain.contours. This extent is considerably less than that re-quired on the hotleg side. (d) The basic plugging criteria instituted at previous outages is adequate. In fact, a slight reduction, to 5/6 row per month, in the outside rows is easily supported by the strain contours and probing results. For the coldleg side 1/3 row per month in the middle of the tubelane is a conservative rate. For the outside rows on the coldleg side 2/3 rows per month is a con-servative rate of growth of the high strain regions.

e Page 10 of.ii (e) The previous program has stablized activity in the wedge and patch plate regions, since no restrictions have appeared in these regions. (f) Impl&~entation of the current plugging criteria, following* this very extensive gauging program, support six months of continued safe operation.

4.

Actual Plugging Pattern Figures 10, 11, and 12 indicate the plugging patterns for Surry Unit 1 steam generators resulting from the application of the plugging criteria stated above.

5.

Secondary Side Inspections The flow slots in the first tube support plate were inspected in all three S/G's. No unusual indications were found and the details are to be used in our on-going evaluation of the strain model * . 6. Tube Plug Verification Photographs of the tube sheets, in order to verify the plugging pattern, will be taken after plugging is completed and before final securing of the manways *.

7.

Initial Findings The unit was shutdown as a result of the expiration of the Order for Modi-1

Page 11 of 11 fication of License da.ted May 6, 1977. Prior to the shutdown, the unit had operated for: six months with a leak rate o'f less than 0.3 gpm. The initial inspection indicated the following leaks at a 500 psig second-ary side pressure: A-S/G Rl4C92 Tube Cold Leg Rl8C57 Plug Cold Leg B-S/G R7Cl2 Tube Hot Leg C-S/G R7C88 Tube Hot Leg R3C26 Tube Hot Leg R1C77 Plug Hot Leg The inspection areas addressed all of the regions where these leaks occurred. The leaking plugs were repair welded using the Westinghouse techniques,

8.

Measures to Improve Accuracy of the Program All tubes which did not previously pass the 0.650" probe and were not plugged were gauged. The list of tubes which were to be gauged will be double-checked at the end of the inspection program by comparing strip charts with data sheets.

.e TABLE 1 HISTORY OF GAUGING RESULTS No. of Tubes Restricting 0.650" Probe at Initial Gauging Program: @ Surry II (3/77) 183 @ Surry I (4/77) 164 . ~i Total 347 No. of Tubes Currently Restricting Various Probes from this 347 Tube Population: 650 610 540 @ Surry II (9/77) 146 20 17 @ Surry I (11/77) 96 65 3 Total 242 85 20

1*.- / l 3.0 2.0 i::: ~ I ~ p::

'.j en 0 H c.,

~ 0 ~ H..,.. 1.0 i:,.:i c.? ~ i:,.:i ~, .*. FULL CLOSURE

• • i"

. *****t. __. .04 .052

• I 5.5 EFPM'S BEYOND FULL CLOSURE*

.11. 5 EFPM' S BEYOND FULL CLOSURE .* ** J

• "*Sur

  • ry I is currently at 6.q_ EFPM's beyond full closure *

.06 .08 .10 AVERAGE F.JCPANSION COEFFICIENT~--~ in. .12 .14 Figure 1. Summary of.Finite Element Computer Runs i ,,. r: ~*. ' .. *r**** ..,... ',~-,.., ::,

'~\\

i..

• e
• Tube Hoop Strain:

1. . J,*,.,, Figure 2a. Tube Hoop Strain at s*.s EFPM's Beyond Full Closure ... } j*. . MIN. 032539 1 .0'5000 3 . 10000

• 5

. 15000 7 . 20000

• 9

, 25000 11 .30000 13 *, 35000 15 , 40000 17 . 45000 MAX. 465334

~--

. *r

. {.. *-:, . \\.* ; .e

• . :. *. *. ~ *_f ii:* -

e MIN 1 3 . j Tube Hoop Strain: ~- 11 13 15 17 MAX Figure. 2b, Tube Hoop Strain at.8,.5 EFPM' s Beyond Full Closure* .03211-92 .05000 . 10000 , 15000 20000 .25000 .30000 .35000 .40000 .45000 . 4G7065

I

~.. e e* Tube Hoop Strain: Figure* 2c. Tube Hoop Strain at 11.5 EFPM's Beyond Full Closure - MIN. 032552

• 1 I 05000 3

. 10000 5 . 15000 7 . 20000 9 . 25000 11 .30000 13. I 35000 15 . 40000 17 . 45000* MAX. 470193

• "i".

. *i-.

/ I <t1--MANWAY SERIES 51 Figure 3, SURRY 1.GAUGING PROGRAM (Hot Leg) NOTE: Cross hatched regions indicate gauging required for 12.5% contour but not for 15% contour, .,. -i:,>' NOZZLE-i>- 1 I -,l

• \\,,

'!J' l' J.. 43 41 39 37. f.3 e 31 29 27 2~ 2; ZI IY 11 1: 13 11 'I 7 5 .3 '.f '.,.. ~,.. ~

/ l I I l . I \\ . l SERIES 51 93 9189 87l'J5 83,'JI 7' 77 '75 73 71 !,,? ~7 1,,51,,3 lD/ 59 57 55 :3 5149 4145 '13"1139 3735 33 3/ 29 21 Z'S 23 21 I') 17 15 13 II 9 7 5 3 / I COLUMNS 94 9Z 90 88 81, M 82 80 78 7~ 74 7t 70 t..S ~" /,,~ ~~ /glJ 58 51,, 54 52 50 4e 41. 44 42 4fl 3tl 31,, 34 32 30 28 2t. 24 2Z 20 /8 11,, /4 /2 /0 8 Ii, 4 2 <:r-MANWAY .-. r*, figure 4, SURRY l GA0GING PROGRAM (Cold Leg) NOTE:,Cross hatched regions gauged in Steam Generator A only. NOZZLE----f> \\,,.-,.,* 4 lo.q:: 44 4~ 42 41 "10 36 3,.., 39 37 --=~ ~" e "\\.';

~ ... n:r..... *..:.* *.... ~:~*~*~-~~~-~-=--*au..-=-~-----~*~ ~ ~*~*.-.-*.... ~*-.:.l!Cmr...... - ..... ~*~*.a&.i:ar - .. ~ i I TDB BOOP S

• . i.

0- ~ '

• Note:
• Atl Tube Considered Rad---L-ea.ks at I

=: i I..,. i I 1

• Support* Plate Locations. Where Flow I

i.

. ! Slots were at Full Closure or Beyo Figure 5. Tube Hoop Strains at Full Flow Slot Closure Occurrence of Leakers at the_ Surry Plants March 77

• MIN 1

3 N: 5 7 9 11 1'3 . -15 27

• • *MAX 0""2...,,

.j 'T / -*

• , 0'+0(;~ *

.08000 . 12000 . 1;nnr 2~/,00 ,c.!;._Jo , l. =* ~'.)0 . ::.~oao

• . :. 100

.363309

/ 5.5 MONTHS* BEYOND F1Jl.L CWSURE

• --~*

.. -*... -** -***~**---*-' 11 *.5 MONma* BEYOND FULL CLOSURE V 11.5 MONTHS* BEYOND

• mL CLOSURE l/3 ROW/MO.

(<rLUMH 15-79) ) ,, J 4 J~ ~ t ' h *t ---* --.... _._.. ~ t ~ * ~ . t t . k

• -i *:
• ij 5

t 6 ROW/K>.. (COLtlm 1-lS & 80-94 ~ ON HO'XLEG SIDE) a et.* P. . ij' l ~ i. . ~

• ~

~- ~ 'f * * ~- '(.

• Li
• 2,,,.."'/MO *.

i *.,'. 3 N.IW. 5 *1 (COLtMi 1-15 & Behill ~ j . ON COLDL!G. SIDE) ~

• (

r ~ F!ftll!Dlla~~~--~~~~~~-,,,ai,~~~~~~~--,,~~~~---~~~~~~~~=--..... ---,. I. Figure 6. Growth of High Strain Contours

• .J

/,-;. ~*:*. r h ' ' ~ ~.... ~ *, ~ l

/ SERIES 51 ?3 'll 89 8713S 83 131 79 77 15 73 71 r,,9 1,,7 t,,5 t,,"5 ID/ 5? 57 55 ~3 5/ 49 47 45 43 "11 :!9 37 3S 33 3/ 29 27 25 23 2/ I'/ /7 /5 13 II 9 1 5 3 I I 94192 90 68 8/.18'1 82 80 78 11,, 74 72 I-10 c.,8 ~" 1,,4 r,,'.£ fpll sa 51,, 54 s2 50 4e 4~ 4~ 42 40 3s 31,, 3q 32 30 2e 21,. 2<1 2i 20,e '"' 111 12 10 B ~ 4 2 I COLUMNS 45 4"3 41 39 37 35 .33 31 29 27 25 23 21 19 17 15 13 11 'I 5 3 ~MANWAY f'IGURE 7 NOZZLE~ SURRY lA STEAM GENERATOR GAUGING RESULTS . *,-,;- ~!' !,. _,. X *, 540" PROBE '>t'=,610" PROOE 0 =,650" PROBE i,. e I

• j

/ I I I j I l .1 I l

• 1 J

I I j i ! ' SERIES 51 SURRY l B STEAM GENERATOR GAUGING RESULTS X =, 540" PROBE "t(=,610" PROBE tJ =

• 650" PROBE

\\. e

/ SERIES 51 93 918913713~ 83131 7? 77 75 73 71 1,,9 t,,7 t,5 t,,'5 k,/ 59 57 55 ~3 5/ 49 47 45 43 41 39 37 35 33 3/ 29 ZT 25 23 21 l'l 17 15 13 II 9 7 5 3 / COLUMNS 18 11,, II/ IZ to 8 !J> 4 Z 43 41 39 37 35 33 31 29 27 25 23 21 19 17 IS 13 II 9 1 5 FIGURE 9 NOZZLE--e:,,. -;; *. ::..:...,:".. ~.

• • !'*. '* '*-~-*. ' 1/",,,.:;i.,

SURRY l C STEAM GENERATOR GAUGING RES UL TS

• -****---**- --*--***** * ****--**rs
  • ,'r,.,,

X =, 540" PROBE -Ji=,610" PROBE ll =, 650" PROBE

r.

e* ._,t,

/ I { j SERIES SI I j 93 9/ 89 137 P,S 83 131 7'i "IT 15 73 71 ~'} I,, 1 kS k3 1,,/ 59 57 55 :3 51 49 41 45 434 I 39 37 35 33 3/ 2'1 21 25 23 21 I? 17 15 1"5 I I ? 1 5 "3

• I I

I I <:i-MANWAY FIGURE *10 SURRY lA STEAM GENERATOR PREVENTIVE PLUGGING PATTERN

---

***- -~-- -********* *---**-**--*-** --------** *----*-----.

-*,*'t'* *.,*/.:.-.*. COLUMN~ /6 lk 14 12 10 8 Ii, 4 2 t--+-++-H--t-'H-++-+-~-4~ NOZZLE~ X = TUBES TO: BE PLU3GED 0 = TUBES PREVIOUSLY PLUGGED : 45 43 4 I 39 31 35 33 31 29 27 25 23 ZI 19 17 I 5 I 3 11 9 -r 5 3 e i .i i

/ I SERIES SI 93 'JI 89 87135 83 81 7? 77 15 73 71 1,,'J IP1 ~,3 t,,/ 59 57 55 ~3 5/ 49 41 45 43 4 f 39 37 35 33°31 2'1 27 ZS 23 2i I~ /7 /5 tJ II 9 7 5 '3 I 1 I I I I COLUMNS '1< I° "(I, M 8t 80 TB,. 14 7' 70 ".... ",.,, 58 S. 54 S2 5o 4' 4' 44 42,, '"" 3' 'i' 31> 28 2' 24 2' i 18,. 14 12,o 8 0 4 2 <d-MANWAY SURRY 18 STEAM GENERATOR PREVENTIVE PLUGGING PATTERN .. **-. ~- ~--*..... *--**-* *-*... -.... NOZZLE--1>> X = TUBES TO BE PLU5GED 0 = TUBES PREVIOUSLY PLUGGED. [* e

/ I I i I I SERIES 51 93 9/ 89 8BS 83 81 7'J 77 15 73 71 ID'J t,,7 t,,5 IP'5 l,,/ 59 57 55 :3 S/ 49 *H 45 4341 39 37 35 333/ '2'1 Z7 25 23 21 /') /1 15 13 If 9 1 5 3 I I I COLUMNS IB lb Ill JZ 10 8 t,,

• 4 2

~-MANWAY FIGURE 12 SURRY l C STEAM GENERATOR PREVENTIVE 'LUGGING PATTERN NOZZLE-{>o X = TUBES TO BE PLUGGED C = TUBES PREVIOUSLY PLUGGED '15 4"3 4 r 39 37 35 33 31 29 27 25 23 21 19 I 7 I 5 I 3 I I 9 7 5 3 /. V

• e I}}