ML20003E761
| ML20003E761 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/31/1981 |
| From: | ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20003E760 | List: |
| References | |
| NUDOCS 8104100458 | |
| Download: ML20003E761 (30) | |
Text
a 4---
-a, . ,e-- 4.-2 ,4 * ',. w DaA .L.s+4 _+._A A= $ M e _4 .a-, a Au-,-- a 4.
...-s - .- -- _ - -- n ---a
" N 1
1-d O-M j ' ARKANSAS POWER & LIGHT COMPANY
i i SERVICE WATER SYSTEM
, INSPECTION'AND MODIFICATION
ACTION PLAN FOR-ANO-2 REFUELING OUTAGE #1 l MARCH, 1981 1
4
(
l 1
O O
e
<8.10.41 o o I/M ,
2R1 - UNIT 2 SERVICE WATER ACTION PLAN
- 1) Change out all 2-inch and under carbon steel piping to stainless steel as shown on Figure 1.
- 2) Add vents, drains for HPSI pump, LPSI pump and CSS pump coolers as described on Figure 2 (unless these coolers are eliminated or replaced by air cooled heat exchangers).
- 3) Add flow rete indication as follows:
Service water flow rate through the following coolers will be added or provisions (isolation valves) added to allow such devices to be installed later during operation:
2VUC-1A, 1B, IC, 10, IE, 1F 2VUC-11A, 118 2VUC-2A, 28, 2C, 2D 2VUC-7A, 78, 7C 2VUC-6A, 6B 2VUC-19A, 198 2VUC-20A, 208 "Also:
2E-52A, 52B 2E-53A, 53B, 53C 2E-47A, 475
- 4) Clean service water bays and pump discharge strainers.
- 5) Inspect portions of service water piping.
- 6) Inspect service water cooled heat exchangers as indicated on Figure 3.
- 7) Replace two failed cooling coils in 2VCC-2B (containment cooling unit). Perform destructive examination of these coils after the outage.
- 8) Replace 2E-358 tube bundle.
l i .
- Provided they are not eliminated by replacement with air cooled' units or by analysis.
t
-- o .
FIGURE 1 The following equipment will have a portion or all of its associated service water supply and/or return carbon steel-piping replaced with 316 L stainless steel piping.
- 1) Containment Spray Pump Coolers 2E-47A&B
- 2) L.P. Safety Injection Pump Coolers 2E-52A&B
- 3) H.P. Safety Injection Pump, Coolers 2E-53A,8&C
, 4) H.P.S.I. Pump Room Coolers '2VUC-11A&B
- 5) Charging Pump Room Coolers 2VUC-7A,B&C
- 6) E.F.W. Pump Room Coolers 2VUC-6A&B
- 7) Electrical Equipment Room #2091 Coolers 2VUC-19A&B
- 8) Electrical Equipment Room #2096 Coolers 2VUC-20A&B
- 9) Emergency Switchgear Room Coolers 2VUC-2A-2D
- 11) Fuel Pool Ht. Exchanger Rad. Detector 2RE-1525
- 12) Containment Cooler Rad. Detectors 2RE-1513 2RE-1519
- 13) Shutdown Cooling Ht. Exchanger Rad. Detectors 2RE-1453 2RE-1456 4
FIGURE 2 I. 2E47A & 2E47B and 2ES2A & 2E528
-1) Vents will be installed between the cooler inlet isolation MOV5 and the coolers themselves and between the cooler outlet and the cooler outlet isolation valves to allew flushing and flow path checking during operation with the service water header pressurized.
- 2) Pressure points for AP instruments will be moved to the small pipe downstream of the inlet reducer as close as possible to the cooler and on the outlet side as close as possible to the cooler and before the pipe increaser.
II. 2E53A, B & C Pressure points will be moved as described in I.2 above from the 3-inch supply and return hecders to the new stainless piping and as close as possible to the coolers themselves to make AP indica-tions more meaningful, i
l l
l l
i l-
[
l l
l I
FIGURE 3 INSPECTION PLAN FOR UNIT 2 SW COOLED HEAT EXCHANGERS-
- 1. Open, inspect, and clean or flush the following coolers during 2R1 outage. These coolers indicated'some reduced flow rate capacity during a January, 1981 test. .
A. 2VUC-1A A S/D-heat exchanger room cooler B. 2VUC-7A A charging pump room cooler C. 2VUC-11B C HPSI pump room cooler D. 2VUC-19B Auxiliary Building electrical equipment room cooler
- 2. To be opened, eddy current examined prior to tube bundle replacement and after new bundle is placed in 2E-358.
A. 2E-35A A S/D cooling heat exchanger B. 2E-35B B S/D cooling heat exchanger
- 3. To be inspected during coil replacement:
2VCC-2B Loop I containment cooling unit
, 4. To be flow checked after piping changeout. The elimination of these coolers by analysis and/or substitution of air cooled heat exchangers is being evaluated and may eliminate the need for this check.
A. 2E-47A&B B. 2E-52A&B C. 2E-53A,B&C
- 5. To be inspected for accessibility of cleaning, inspection and mainte-nance / replacement. The result will be sketches, photos and proposed design changes to improve accessibility.
A. 2VUC-1A, 18, 1C, 1D, IE, IF S/D cooler area room coolers B. 2VUC-11A, llB C HPSI pp room coolers C. 2VUC-7A, 7B, 7C Charging pump room coolers D. 2VUC-6A, 6B EFW pump room coolers i E. 2VUC-19A, 19B Aux. Bldg. Elec. Equip. Room Coolers r "I';C-20A, 20B Aux. Bldg. Elec Equip. Room Coolers
,11C-2A, 28, 2C, 20 Switchgear Roo; Coolers
- 6. Remove and recalibrate or replace the followin* instruments:^
A. 2PDIS'1464-1 A HPSI pump cooler AP '2E-53A)
B. 2PDIS 1462-1&2 C HPSI pump cooler AP 12E-53C)
- 1. 2PDIS 1457-1 A Containment spray pump cooler AP (2E-47A)
- 3. 2PDIS 1459-2 B Containment spray pumi cooler $P (2E-478)
- This may be unnecessary if the need for these coolers is eliminated or '.he coolers are replaced by air cooled units.
j
.(
Thornos M. Lofonge, Inc.
.j 10439 N.E. FOURTH PLAIN ROAD e P.o. Box 4448
- VANCOUVER.
WASHINGTON 98662 * (2C6)2541213
. i .(J ,
iz.
December 15, 1980 ARKANSAS POWER & LIGHT COMPANY P, O. Box 551 Little Rock, Arkansas 72203 Attention: Mr. Dan H. Williams, Generic Projects Coordinator
SUBJECT:
ARKANSAS NUCLEAR ONE - UNITS 1 & 2 SERVICE WATER SYSTEMS PRELIMINARY FINDINGS AND RECOMMENDATIONS AP&L CONTRACT NO. L-020G, TASK NO. 00lP, PLANT AND T.M.L. PROJECT N0. 032-01-001
Dear Mr. Williams,
As we discussed in Little Rock, this report is being generated to summarize our preliminary findings and recorrendations. We are sending this report in an effort to provide you with as much information as is possible in the shortest period of, time. We ' realize that you are operating on a very tight and critical schedule.
We are enclosing fi' teen (15) copies of this report with the original.
We have not distributec any copies of this information other than to our 1
l files. Therefore, please distribute this letter report to the proper
! individuals. -
In the interest of time we will not be submitting a formal 'eibliography l referencing the source of statements made within this document. Please be assured that we will make every possible effort to document the
! efficacy of any statements contained within this report and/or the j
source of any information used in the preparation of this document.
! This will be formally done strictly upon your request. I t
We have written this report with the intent that this will be used Quality for Industry
Thomas M. l.oronge, Inc.
ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 2 strictly as an information source to ARKANSAS POWER & LIGHT COMPANY. In other words, we are being extremely direct. Obviously, we are outsiders to the problem at hand. As such, some of our interpretations might err due to insufficient information. We strongly recomend that ARKANSAS POWER & LIGHT COMPANY make certain that they agree with any of our statements before the information is disseminated to outsiders. We additionally ask that af ter you have reviewed this document you notify us promptly of any errors which we have made. This information will be corrected in the final report.
BACKGROUND Essentially the background information is well known to all. The Service Water Systems of both AN0-1 and ANO-2 have, upon inspection, been found to be experiencing apparently excessive corrosion, biological slimes, silt, mud and Asiatic clams (presumably Corbicula fluminea).
These generalized waterside phenomenon could be critical to operations and/or critical to safety. In all cases the solution to these problems appears to have a rather significant economic impact.
I It is a reasonable assumption that the fire protection systems associated with AND-1 and ANO-2 could suffer from problems similar to those of the respect.ive Service Water Systems. Therefore,' this subject must be utvestigated in some detail. However, this will not be done I directly in this work as it is outside of the presently authorized scope under subject.
l; 1
' It is reported that the condition of this Service Water System at b ANO-2 is believed considerably worse than is that at ANO-1. During recent inspections an accumulation of silt, mud and adult clams in the Service Water System at ANO-2 was found. Fewer clams, little silt and j;
l' some biological slimes were found ir,i the AN0-1 Service Water System.
4
!^
li . . --- - - _ - - - . , -
Thonns M. Loronge, Inc.
ARrJNSAS POWER & LIGHT CCfGANY Cecember 15, 1980
. Page 3 -
l One of the questions which was raised in our initial meetings was why does this difference exist.
1 Along these same lines, the component cooling water heat excnangers, 2E28A, B & C. appear to be in censicerably worse cor.dition with respect to cerrosio:. and structura; integrity than co their parallel functicnir; exchangers of AfiG-1. These latter exchangers are designated as the intermediate cooling water exchangers, E28A, B & C.
The high pressure safety injection heat exchangers of A!;0-2 acpeared to be in tne worst ccndition upon inspection. The next worse exchangers were rescrtedly 2VUC24 A & B and subsequ_.>tly 2VUC20 A & S. The importance of this cbservation is the simple fact that all of these exchangers are judged to be in the categcry of " critical to safety'.
l The higr.est density of Corbicula was found in the centinment service water cooling coils. Excnangers 2VCC2 A, C & D reportedly have the worst biclogical ;cpulation. Claes and/or evidence of clams were found in VCC2 A, 3, ; & D. Cla- snells were found in both systems. The
location of the clam. .nells tenced to be at the icwer elevations.
Finally, meta!lurgicai failures of the shut down cooling heat
- exchangers, 2E35 A & B, have been recorted. The design of these exchangers e is such that enly 2% of the approximately 750 tubes per excnanger can be plugged without aff ecting power plant heat transfer requirements. At i the present time twelve (12) tubes in 2E35 A are plugged and fcurteen (14) tubes in 2E35 3 are plugged. We understand that both of these exchangers ecploy 304 stainless steel tubes in a carbon stee; shell.
F The cooling water is reportedly en the shell side.
1 1
i Y
1 i
M
e . .
Thomas M. Lorong, Inc. l
.. ;
ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 4 1
MAKE UP WATER - SOURCES AND COMPOSITION l
It is our judgment that any resolution of the existing problems at ANO-1 and/or_ANO-2 should be based upon the assumption that a single, marginal quality makeup water source exists for these units. We make this statement simoly because the quality of the water in the emergency cooling pond is judged to be mar 9 N 1, the City of Russellville, Arkansas I
4 has water which is judged to be marginal, the quality of weli water in .
the irmediate area is judged to be marginal to poor ar.d the quality of Lake Dardanelle is also marginal.
Given this Information the first item of importance which one must have is an idea of the water quality which is capable of er.tering the intake structure o' both units through. the inlet canal. It is our opinion that the >: ster chemistry data which exists was not collected +
with the idea that the water could potentially have negative impact on the Service Water System. As such, t everal parameters were not, .apparently, examined in detail. These parameters such as total sol Ms ar.d suspended solids do not appear to have been given the necessary position of importance.
Please understand that this is not a criticizan, but rather an observation.
In fact, this statement will be used as the basis for several recomendations in our work. ,
Because of these conditions, one (1) of the first problems which has to bo resolved relates to the range of water quality expected at the
- service water intake.
' Along these lines, we have prepared Attachment I and Attachment II 1
- of this report. Attachment I shows a synthesized range of antic'. pated j
- water quality. While this ray apparently be conservative, we do not think so. Rather, we think this to be highly realistic. Had we wanted I
to be overly-conservative, we could,have greatly extended the ranges shown.
s t c A -
Thomas M. Loronge, Inc.
ARKANSAS POWER & LIGHT COMPANY December 15. 1980
. .Page 5 Attachmer! II is the result of calculations which we made with the values of the parameters presented in Attachment I. We did not construct the ranges so that the calculations came out to any certain valuerd Please note that the maximum temperature which we have used in this 0
work is 130 Fahrenheit. We are aware tha'. the water in the Service However, Water System could potentially reach a tenperature of 150 F.
we believe that it is more realistic to look at an upper temperature limit of 130 F for these purposes.
The results of our work show that the service water quality can range from relatively scaling with respect to calcium carbonate to extremely corrosive. In fact, we would predict that under the majority of conditions the service water would tend to be corrosive. .
An examination of the majority of available data suggests to us a I- need for upgrading the existing chemical monitoring program. We would recommend that total solids and suspended solids be conitored at the service water intakes of both units at least once per week. We additionally believe that rather extersive corrosion testing should become a part of l l _ _ _ _ . .
a permanent program at ANO. This program should utilize corrosion
( coupons placed in properly operated cooling water loops at various points in the rystem. The data from the corrosion coupons' could be supplemented with data gathered through the use of corrosion rate reters.
Additionally, we would recommend the installation of several spool l -
i
' piecee of pipe at critical locations. These could be put in a bypass aucn that they could be readily removed for purposes of inspection and H analysis. As a portior. of our work scope, we will present more specific l
details on our recommended monitoring program.
l Obviously, the collection of data costs money. As such, there should be a specific reason for this collection. The first reason which l
i:
i t
Thomas M. Laronge, Inc.
ARKANSAS POWER 5 !.IGHT COMPANY December 15, 1980 Page 6 we offer is the support of our earlier statement that insufficient data exists to characterize the response exp'ected from cooling water heat transfer equipment. Hopefully, the accumulation of data will lead plant operations to' the establishment of guidelines designed to avoid costly shutdowns, perform preventative maintenance and to assess overall system performance.
The program is best designed to answer some of the questions relative to the variability of the service water influent with respect to suspended solids, etc. It was reported to us that the lower temperature of the water tends to occur between the months of January and February.
The highest temperature of the water tends to occur in the months of July and August. The greatest turbidity of the water tends to occur between March and Hay. While this may be the case, it is not apparent from the existing body of data. Additionally, the concern should be placed upon the actual measurement of suspended solids and not upon the measurement of just turbidity.
~
The chemistry staff of ANO does perform the analysis for certain water quality parameters on both the inlet water, discharge water and recirculating cooling water. As a portion of our work, we examined l
welve (12) (approximately one per month) of the Cooling Tower / Circulating Water Analysis Report.
Perhaps the results which were delivered to us were not representative.
However, if these result: ere representative of the analytical work
' being done on the service water infiuent, we must conclude that it is not sufficiently complete. To explain this statement we reviewed thirteen (13) individual parameters. Of these thirteer. (13) individual parameters, values appeared on each sheet for only three (3). Of the remaining ten (10) parameters the quantity of reported information existed at 50" or less for nine (9) of the parameters. Simply stated, there were too many blanks on the report to our way of thinking.
Thomas M. Lcuonge, Inc. .
ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 7 The obvious implication of this is simply that insufficient work is being done. We wish to make it clear that our -investigation shows this not to be the case. In fact, we judge the most significant problem as being the existence of a smaller than desirable chemistry staff at both units. In support of this statement we ellocated the time spent by the six (6) plant chemists who comprise the total staff of ANO-l a'nd AND-2.
We assume that the Chemistry Supervisor is expected to devote his full time to~ supervision. We then calculated what we consider to bs the-demands .placed upon the plant staff simply by environmental requirements.
This totals 7.4 man weeks per month of direct environmental labor or 28".
of the total, twenty-six (26) man weeks, of the available total labor force. In other words, only 52.81, of the total available labor or 13.7 man weeks per month are available to perform routine coerating chemistry, etc.
'/ , We believe that this staff could be effectively f augmented with people. We believe this recomendation to .have major benefits to ARKANSAS POUER & LIGHT COMPANY. At least, there would appear to be a need for a "special projects team". Perhaps some of the routine chemical analytical work could be done by skilled technicians 'with some of the plant chemists speariwading special pr ,;,.; cts. Our experience with nuclear power plants suggests that "special projects" are the rule and not the exception.
i We recently had the opportunity to establish the operating bar for the staff of the chemistry department of a nuclear unit. It was our l
feeling that the minimum staff should consist of at least one (1) supervising
' chemist, one (1) plant chemist and seven (7) to eight (8) chemistry l technicians. Unless we are missing some very important information, it would seem 'that this work which we recently completed has a direct parallel to the needs of ANO-1 and ANO-2.
If you are to continue operating ANO with the existing staff, we would recomend that you give consideration to adding between three (3)
I f
Thomo<s M. l.c,ronge, Inc. .
ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 8 and four (4) members to your existing staff for the purpose of performing specialty analyses, specialty inspections, long term projects in support of operation and snort term projects in support of operation.
SERVICE WATER SYSTEM DIFFERENCES Af ter carefully reviewing the available information, we find several plausible explanations for why Unit 2 Service Water System appears to be experiencing more problems than does that associated with Unit 1.
Overall, we believe that the design basis for the Unit i system is considerably better than is that of Unit 2.
Shellside, U-tube and/or straight tube heat exchangers tend to be subject to many more corrosion and fouling problems than do their tubeside analog:. From reviewing the drawings of your system, we believe that' We you have several shellside coolers on ANO-2 Service Water System.
l pr- could not locate any shellside exchangers on ANO-1.
i d i ,' We believe that the following coolers on ANO-2 are shellside exchangers.
- [ We additionally believe that each of these are U-bundle type exchangers, including
2E35A, B ,
2E47A, B 2E52A, 8 2E53A, B, C l
) It is con eivable that we have not identified all of the shellside exchangers on ANO-2. Considering the service to which these exchangers l a .aellside exchangers are being subjectad; we ,vould have preferred that n be employed. Most industries which use shellside exchangers experience consistently more problems with these exchangers than they do with tubeside exchangers.
A Thomo,s M. Loronge, Inc.
ARKA!!SAS POWER & LIGHT COMPAfD December 15, 1980 ,
Page 9 The design of the intake. structures for Unit 1 and Unit 2 are considerably different. The flow to the intake bays appears to have d Essentially, heavy-widely different velocities at Unit i ar at Unit 2.
siliceous material appears to settle in front of the intake structures associated with Unit I while it carries through into the same associated with Unit 2. This tii6rnation has been satisf actorily documented through the several inspection reports written by ARKANSAS POWER & LIGHT COMPANY personnel. -
We suspect that the average velocity of cooling water in the Unit 2 system is, overall, considerably lower than.is that in the Unit i system. The former systtm is obviously larger sud contains a greater number of heat exchange components. Along these I f nes it would appear that Unit 2 Service Water System operates with a significantly higher differential pressure than does that associated with Unit 1.
The metallurgies of both service water. systems have been reported to us as being extremely mixed. As a minimum, we are told that Unit i Service Water System contains carbon steel, aluminum, copper, galvanized That of Unit 2 ccqtains, s, teel, Adniralty and 304 stainless steel.
by report, carbon steel, 304 stainless steel, copper, 90/10 copper-nickel and Admiralty. It would seem that both syster.s could benefit from a reduction in the number types of material employed!
The intermediate cooling water exchangers associated with Unit 1 The appear to be physically located near the service water intake.
component cooling water exchangers associated with Unit 2 appear to be Therefore, the located near the discharge of the Service Water System.
latter tend to be the " garbage can" for everything in tront of them in the system, i.e. , corrosion products, silt, slimes, etc.
There are some rather obvious differences in the elevations of the
/ Thomas M. loronge, Inc.
'ARKAftSAS POWER & LIGHT COMPANY Oecember 15, 1930 Page 10 various exchangers of each of these systems. We would suspect that a thorough problem analysis might show some correlation between the problems and the elevations of various system components.
We believe that some of the heat exchangers associated with Unit I tend to run at somewhat higher . temperatures than do those associated with Unit 2. We are strictly concerned with the differences between the intermediate cooling water exchangers and the component cooling water exchangers. The FSAR for Unit 2 shows that the total heat' load on the CCW exchangers is 52,000,000 Btu per hour. Under normal oper'. tion two (2) of the three .(3) component coolers would be in service. The rated flow for this service is reportedly 4,860 gallons per minute. The operating temperature differential across this system is designed to be 11.3 F. From other information supplied to us by ARyaNSAS POWER & LIGHT COMPANY the actual flow to these exchangers is 4,600 gallons per minute.
Using these nucbers one can calculate a simple error. Either the total heat load on this system is in error by approximately a factor of two (2) or the. cooling water is low by a factor of approximately two (2).
In other words, if one calculates the heat sink of the cooling water using these nunbers, it is found that approximately 2.0 5tu per hour per F are rejected. Obviously, this is an error by approximately a factor of two (2). '
If one examines similar data supplied for ANO-1, the numbers show that the operating temperatures of the intermediate coolers differ by 21 F on-the waterside. The total heat load is 30,000,000 Btu per hour.
The associated water ficw is 2,800 gpm. Making a similar calculation from this information yields a heat sink to the cooling water of 1.0 Btu per pound per F. Obviously, this is reasonable. What is significant U
is the difference between the heat removal across these units and their operating temperature ranges. The process side of the component cooling water heat exchangers has a design maximum temperature of 114.3 F.
Thomas M. l.oronge, loc.
ARr.ANSAS POWER & LIGHT COMPANY December 15, 1980' Page 11 That associated with the intermediate cooling water heat exchangers is 125 F. This is one of tne major Jifferences between the Service Water Systems of ANO-1 and ANO-2.
In summary of this information, we would prefer to have the Service Water System associated with ANO-1 in our plant as opposed to that associated with ANO-2. We would predict the occurrence of more problems on that associated with ANO-2. We would predict the difficulty of-controlling problems to be considerably greater on ANO-2 than it would be on AN0-1. This latter comment is a direct offshoct of the inclusion of shellside exchangers on ANO-2.
SERVICE WA7ER SYSTEM METALLURGY At the ostset, the ideal system would employ compatible metallurgy s ch that only slightly differing galvanic couples exist between the various components associated wit 5 the Service Water System as well as those associated with the balance of plant. In both ANO-1 and ANO-2 we -
wculd prefer to see no copper, no zinc, no copper alloys and no galvanizad materials. Obviously, it would be advantageous to also not have to use carbon steel. However, given proper water treatr.ent, carbon steel could be reasonably _ predicted to perform adequately. .
Component failures have been experienced with alloys containing both copper and stainless steel. The failures associated with the forcer material have been related to the presence of sulfur and/or its compounds. The failures of the 304 stainless steel have been :ttributed to phenomena associated with the presence of cbloride in the water.
At the present time we understand that ARKANSAS POWER & LIGHT COMPANY is considerino changing the tubirg associated with the shutdown cooling heat exchanger if ANO-2'to,an alloy designated as E-Brite 26-1.
Thomas M. Loronge, inc.
ARKANSAS POWER & LIGHT COMPANY December 15, 1980-Page 12 We believe that we understand the reasons for this selection of material.
However, we also . feel that the problems which have brought about the need for change cannot reasonably be expected to be solved by simply changing out the metallurgy of single components. We realize that th'is type of retrofit maintenance offers your system a condition of improved quality material.
However, we also believe that you are expecting the metallurgy of your system to perform some services which it may not do very well.
1 Very few alloys of steel would be reliably predicted to withstand th? underdeposit corrosion phenomena associated with the presence of Obviously, large accumulations of silt, crud, deposits and/or slimes.
some materials are better than are others. However, as a general rule, stainless steel should be operated such that its surfaces are kept
' essentially clean. In all cases, we would recommend laying up this type p'
of system in a clejn mode.
Before proceeding further, we have considered a wide variety of metallurgy which could be applicable to your needs. In each of these cases we have attenpted to rate the performance of the metal as it would be expected to hold up in service.' We have specifically rejected from further consideration the use of copper-containing alloys.
li The reason for this latter decision is simply that many of your 1.
heat exchangers associated with the Service Water System of ANO-2 appear to be subject to anaerobic conditions, adverse bacteriological growth, etc. When this type of condition exists, sulfur and its compounds ll typically attack the surf aces of copper-containing alloys. In our judgement, this is sufficient reason for rejection of these materials at
' this point. We believe that your experience will support this judgement.
The next a. oy which we advise, ARKANSAS POWER & LIGHT COMPANY to
Thomas M. Loronge, Inc.
ARYANSAS POWER & LIGHT COMPANY December 15, 1980 Page 13 reject from further consideration is titanium. While titanium is a
" super" material, it is costly and difficult to fabricate. Additionally, titanium tubing-is typically installed in heat exchangers employing thinner walled tubes than those associated with other matt-ials. Because of this fact, the need for extremely careful design and operation of heat exchangers containing titanium tubes is great. We do not feel that this lends itself to the retrofit conditions at your nuclear power generating station. We also do not feel that you would be sacrificing any quality by not using titanium.
The following is a list of alloys which should be considered in this discussion:
Alloy ;;ar:e Alloy Predominate Structure Incone) 625 Austenitic Incoloy 325 Austenitic AL 29-4C Ferritic AL EX Austenitic E-Brite 26-1 Ferritic
316 Austenitic 304 Austenitic In your service, we feel that both 304 stainles~s steel and 316 stainless steel are not good choices of materials. We would make the same statement about respective "L" grades. Certainly, the 304 is not acceptable. The 316 would be predicted to perform considerably better c-than would the 304 This is particularly true with respect to pitting
! corrosion. However. the 316 alloy is not particularly good where crevices exist.
To facilitate consideration of one (1)' item, you will find that we have listed the alloys above in order of decreasing cost. When one is looking at " exotic" materials, cost is a major factor. For example, 4
Thomos M. Loronge, Inc.
ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 14 Inconel 625 would probably be about four (4) times the cost, at least, of E-Brite 26-1. Incoloy 825 would be approximately twice the cost of E-Brite 26-1.
In our opinion. AL 29-4C and E-Brite 26-1 offer the best resistence to stress corrosion cracking of the reasonably priced alloys. In other words, we are eliminating Inconel 625 and Incoloy 825 from further consideration because of cost. .
We . judge AL 29-4C to be superior to both AL 6X and subsequently to E-Brite 26-1 with. respect to its resistence to both pitting and crevice corrosion. In a truly fresh water environment we would be tempted- to not draw distinction between the pitting and crevice corrosion responses of E-Brite 26-1, AL 29-4C and A1 6X. In a seawater environment, we judge AL 29-4C and AL 6X to be better than E-Brite 26-1 with respect to its resistence to pitting and crevice phenomena. Therefore, the question is how does one go about judging the quality of water at ANO-l and ANO-
- 2. We are adopting the philosophy that "an ounce of prevention is worth a pound of cure".
To +.he-best of our knowledge AL 29-4C and AL 6X are not properly certified to meet your code requirements. However, we believe that both alloys could be certified on an expedited basis. We are aware that you have discussed this with respect to AL 6X. However, we have not seen any mention of AL 29-4C. We would think it in your best interest to further pursue this matter.
e There is one very significant recommendation which we would offer to ARKANSAS' POWER & LIGHT COMPANY as a consideration when upgrading your existing heat exchangers. Obviously, the metallurgies associated with tubes, tube sheets, stells, valves, piping, etc. must be sufficiently compatible from the galvanic corrosion ~ point of view. The raaterials
Thcmas M. l.ofonge, Inc.
ARKANSAS POWER & LIGHT CC+1PANY December 15, 1980 Page 15 which we have just discussed as being wise recommendations for you to consider as candidate tube materials are considerably more noble than is carbon steel. As a result, we would not recommend your retubing heat
[ exchangers in such a way that the galvanic cerrosion potential _ increases.
- This situation must be looked at very carefully on an individual system element by element basis. Along these lines, we would suggest that one of the.most suitable materials for_ tube sheet construction in an upgraded exchanger consisting of the metallurgies we have recommended might be AL 4X. This material contains abour. 4-1/2t molybdenum, should be readily available and should lower the galvanic couple between system elements of construction. We are not certain whether AL 4X ceets your code requirements. However, this is simply a matter of a telephone call. If you seriously consider the use of this alloy, we would be happy to get the information for you. .
While this is not directly a technical consideration, we think it wise to determine which " fixes" could be capitalized and which " fixes" are simply subject to expensing. We anticipate some highly attractive investment tax credits to be available in 1931. We suspect that new bundles may be subject to such tax credits while retubing may not.
SYSTEM DESIGN CHANGES During your upcoming refueling outages we would recommend the modification of both service water systems wherever possible.
- The most important recommendation would be for ARKANSAS F0WER &
LIGHT CGMPANY to clean each element of the existing system as thoroughly
'I as is possible. This recommendation is not as straightforward as it may scund. The execution of the required cleaning operations may prove to be extremely difficult.
Thomas M. Lcironge, Inc. .
ARKANSAS POWER & LIGHT COMPANY December 15, 1480 Page 16 To facilitate the cleaning operations, we would suggest that each C individual heat exchanger be valved at their respe.ctive feed and disc,arge h
)'
h.eader.s . Where possible, flushing c.o..nne.ctions should be installed.
'i . Pressure indicating _egipment and/or flow indicators should be installed ,
. wherev'er possible. 'These should best be set up so that functional-monitoring can be conducted during operation subsequent to the refueling outages.
We are aware of your plans to additionally replace small bore pipe, 5 -1/2 2 inch pipe, with 316 L alloy material. This procedure will obviously upgrade your system considerably. However, we still believe that it is necessary to make every possible attempt to operate your.
system in a clean fashion. Components which are not on the line continually must be flushed prior to layup. Components which are on line continually should have sufficient velocity during operation to enable the transport of siliceous materials from the inlet through the outlet on a quantitative basis. These conditions alone are predicted to go a long way towards I eliminating the build up of corrosion products, silt, biological slimes and Asiatic clams in your Service Water Systems.
( We would also suggest that you give serious consideration to lining l(
f the water boxes of your condensers. We understand that ANO-1 does not employ a cathodic protection system. We also understana that the cathodic protection system on ANO-2 does not work properly. For these reasons, any steps whien can be taken to line these water boxes would seem to be much i
to your advantage.
As we have indicated throughout our work, we judge your corrosion monitoring program to be less than adequate. During July and August of 1980 your water treatment chemical vendor installed a single set of corrosion coupons of three (3) different materials in your recirculating cooling water system associated with ANO-2. The results obtained from 1
Thomas M. Loronge, Inc.
L ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 17 this work are judged to be highly unsatisfactory, These corrosion rates were reported to you as ranging from 4.3 milligrams per square decimeter -
per day with a copper-nickel alloy of unspecified concentration to 764.3 milligrams per square decimeter per day on carbon steel. While this is only one (1) set of results, these are not very encouraging.
Along these same lines, we strongly suspect that you ought to be able to operate your recirculating cooling water system without specialty chemical treatment. We believe that you could properly feed a combination of sulfuric acid and gaseous chlorine to this system at reasonably low corrosion rates.
With respect to keeping the service water system clean, the recirculating water system clean and the once through cooling water system clean, we would hold very little hope for proprietary dispersants. Most of these dispersants tend to be water suspensions of polyacrylates and/or polymethacrylates.
Essentially these materials operate to lower the bulk density of the siliceous materials present in the raw water. With a lower bulk density, these materials tend to carry through the system to the point of discharge rather than settle out in the system. Our estimation of the cost for.
treating these units chemically seems to be considerably higher than does yours. We would predict that this would prove to be somewhere between
$150,000 per year and $300,000 per year minimum for chemicals alone. In addition, highly adverse affects could be experienced in components of your system which continue to have dead areas and/or which are laid up in the presence of water-containing solids plus chemicals. Many salts e of both polyacrylates and polymethacrylates are insoluble. Excessive concentrations of these materials tend to be very viscous. Additionally, these materials tend to be biodegradables, i.e., food for biological organisms. We would recommend that every possible effort be made to rot rely on the feed of such specialty chemicals as a solution to existing problems. We regard this as a last ditch, trial and error measure.
~
Thomas M. Loronge, Inc.
ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page.18 When performing any mechanical modifications on your system, we would strongly suggest that all modifications provide for the_ maximum possible degree of ease with respect to accessibility to system components.
~
Whe'er piping andt Seat exchangers can be open, 5kK NS'AS' POWER & l.IGHT COMPANY will have o tdvantage. This includes such items as the relocation of branch connections off headers from the bottom of pipes to the top of pipes. Incidentally, this was not our idea. All credit for this recommendation should be given-to ARKANSAS POWER & LIGHT COMPANY personnel.
- ' The installation of flushing conriections on the shells of any shellside heat exchangers is recomended. We also recommend the installation of inspection ports..
Any modifications which result in a demand for electricity during operation and/or critical safety codes should first consider diesel generator capacity at ANO. Care should be taken when installing motor operated isolation valves, etc. to make certain that the diesel generator capabilities at ANO can adequately support this increase in electrical demand, r Wherever possiblE. pipe connections should avoid the creation of f5 -
stressed areas and/or reduced diameters. In other words, crevices as well as constrictions should be avoided at practically all costs. Stress relieving of welds is considered a "must" to preclude future problems at weld heat affected zones.
- In conjunction with all of this work, we advise that you re-evaluate l . the. quality assurance and quality-control programs applicable to both Service I d Water Systems as well as those applicable to other plant water systems.
We suggest that any systems requiring chemical monitoring should require the analytical procedures to be fully standardized at least ence per week.
Incidentally, this is a minimum to our way of thinking. We suggest that I
Thomas M. Loronge, Inc. .
-ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 19 inspection procedures be set in such a way that significant areas of the A
same piece of equipm.ent be inspected each time equipment is opened.
detailed record of this inspection report should be kept. " To facilitate
~
such record keeping, we would suggest that a Critical Inspection Report form be established whfch forces the inspector to fill out information about the specific areas of the equipment in question. From these, accurate system histories can be constructed.
THE ULTIMATE SOLUTION The ultimate solution to the problems at ANO-1 and ANO-2 under discussion rests with prolonging the safe and reliable service life of all systems and their components. As a corollary to this recommendation we offer the state:ent that this should be done at optimum cost. It is very important that one look at optimum cost rather than at low cost.
The reason for this statement is simply that in going from one material of construction to a more exotic material of construction in a given system one may simply be prolonging the time to failure and not eliminating the potential for failure.
We have reviewed the several discussions and the written report concerning the installation of backflushable strainers at the inlet of the Service Water Systems on both ANO-l and ANO-2. We are also extremely familiar with the strainers being considered. We believe these strainers to be of top cuality. We further believe that their producer is a relatively easy company with which to conduct business. What we don't know is whether these strainers will work.
The biggest problems which we see with the ANO systems are those which primarily result from the inclusion of silt and corrosion products within the piping associated with the Service Water Systems. We view the other biological problems, chloride stress corrosion problems,
. o Thomas M. Loronge, Inc.
ARKANSAS POWER & LIGHT COMPANY December 15, 1980 Page 20 sulfide induced attack and/or specifically the Asiatic clam problem to be ancillary and/or secondary. The elimination of silt from your systems promises to be perhaps the single most important consideration. Obviously, the elimination of corrosion product accumulation is being termed as equivalent to the elimination of silt. In other words, the corrosion products are being considsred, in the light of this discussion, as a silt. Af ter all, this material or debris simply is transported from one point in your system to another point in the system,where it further promotes corrosion and other undesirable effects. .
Before leaving this point, we do not agree in any way with several of the statements. which have been presented to you relative to the level of chlorides which are tolerable in your water. It is our experience that the tolerable level of chlorides in a given system containing stainless steel components is strictly system specific and very difficult to predict. Minute quantities of chloride in the bulk water phase can concentrate at surfaces to hundreds to thousandths of parts per million.
This can then result in underdeposit corrosion, pitting, etc. In fact, this phenomenon is well known to NSSS vendors. To the best of our knowledge the cost rigid specifications existing among vendors require that bulk chlorides in water contacting stainless steel be limited to 0.15 mg/L. This same specification requires the surface of piping to f
not be contaminated with more than 0.0015 milligram per sq'uare decimeter L
l of chlorides. Obviously, this quantity of chloride in the bulk phase of n
I water is considerably less than the 3 mg/L value which has come up in discussion. In otner words, the system must be kept clean and the chlorides should be kept as low as is possible.
We view the reliance of eliminating Corbicula and/or other future molluscs from habitating in your water systems to be somewhat of a l
gamble if only strainers are used. Additionally the supplemental use of chlorination is not the most desi,rable procedure.
l l
I
Thomas M. Lcuonge, Jnc.
ARKANSAS FOWER & LIGHT CC14PANY December 15, 1980
-Page 21
'To our way of thinking, the most desirable procedure would be to install closed loop cooling water systen.s in place o.f the existing once
/[h through service water systems.
A reasonable alternative might be the installation of clarification equipment and/cr filtration equipcent. Considering the capacity of this
] equipment to be able to handle approxicately 40,000 gallons per minute of water over a wide range in temperatures, one can see readily what- the cost of this equipment might be. The cost for what' we consider to be the best clarification equipment on the market culd be somewhat under 52,000,000 at the present time. The cost for the proprietary elements of a suitable filtration system capable of polishing the clarified water would be expected to range just under 51,C00,000. The cost of single stage, front end filtratien equipment is estimated to cost S2,500,000 to 53,000,0C0.
More detail on these alternatives will follow in our final report.
We strongly believe that clarifier sludge can be recategorized for ease of disposable. However, we also acknowledge this to be a very realistic problem which must be addressed squarely. One alternative which might suit-ARKANSAS PCWER & LIGHT COMPANY's needs would be to consider building a water treatment plant which coulc service the needs We believe the City of of the City of Russellville, Arkansas, etc.
Russellville is in rather severe need of an upgraded water treat ent system. In addition to potentially providing an economic advantage to ARKANSAS PCWER & LIGHT COMPANY such a system could upgrade living conditions
- in the area adjacent to ARKANSAS POWER & LIGHT COMPANY's operations.
In other words, the needs of both the comunity and of the nuclear plant could be satisfied in a single venture.
We would reco=end that every possible effort be made to construct .
the-cooling water system modifications in such a way that they do not
} require special qualifications. -In other words,. we vould recorx:end that t
'- _ the existing open recirculating system be lef t intact as a bypass to any a
l
- Thomo6s M. Loronge, Inc.
ARKAflSAS POWER & LIGHT COMPANY December 15, 1930 Page 22 system modification. Obviously, this recommendation would require that certain motor-operated isolation valves be installed at important points in the system such that wh.en safety considerations require, the appropriatt valve line up will result.
CONCLUSION Mr. Williams, we believe that this report contains both a sizable number of recommendations and some highly important recomendations. We also view this report, as previously stated, as being preliminary. Because of this fact and in the best interest of time, we would ask that you contact us with your comments and those of your associates as rapidly as is possible. We, in turn, will make every effort to factor these coments directly into our final report preparation.
Thank you once again for the opportunity to be of s'ervice to you and your associates.
Very truly yours, W -
Thomas M. Laronge, President TML:mt 1
Original + 15 Copies 4
Thomas M.Laronge,Inc.
ATTACHMENT I
. l I
RANGE OF ANTICIPATED SERVICE WATER QUALITY Low High Average 2 Parameter 6.5 9. 5 8.2 pH, pH Units 50 225 Tctal Hardness, mg/L as CACO 3 10 90 44 Calcium, mg/L as Ca 1 25 Magnesium, mg/L as Mg 30 165 Sodium, mg/L as ita 0 10 Potassium, mg/L as K Total tron, mg/L as Fe 0.1 1 Total Manganese, mg/L as Mn 0 1 40 120 80 M Alkalinity, mg/L as CACO 3 0 0 0 P Alkalinity, mg/L as CACO 3 Chloride, mg/L as C1 40 200
-20 100 Sulfate, og/L as S04 0 10 111trate, mg/L as 803 Fluoride, mg/L as F 0 1.5 4
0.2 10 Silica, mg/L as SiO2 Total Of ssolved Solids, mg/L 150 800 350 10 100 50 Suspended Solids, mg/L 160 900 400 Total Solfds, mg/L Equivalent Specific Conductance, trnhos/cm 250 1,200 10 80 Turbidity,ilTU 3 33 130 100 Tempera ture, F Notes for Table I:
- 1. The values which appear in this table have been strictly synthesized for the purpose of generating a reasonable working base.
- 2. The term averace actually has little to no meaning. This is presented here for purposes of calculating a Langelier Saturation Index and a Ryznar Stabi_lity INdex. ,
- 3. This average temperature value assumes that the water is sampled at the discharge of the service .,ater system.
- Thomas M.Loronge,Inc.
ATTACHMENT II RANGE OF ANTICIPATED SERVICE WATER TENQENCIES l TO SCALE WITH CALCIUM CARBONATE OR TO BE CORROSIVE TO MILD STEEL Langelier Ryznar Saturation Stability
' Index Index
- Highest apparent scaling tendency 2.6 4.3 water composition3 ,5 Lowest apparent scaling tendency
-?.0 12.5 water composition4 ,5 0.5 7.3 Average water composition Notes for Table II:
i
- 1. All calculations are based upon data taken from Table I.
- 2. All calculations are approximate.
c L Calculations based upon the assumption that the worst scaling water
!: 3.
occurs when pH, alkalinity, ' temperature and calcium are at the I-maximums while total solids are at the minimum.
l-
- 4. Calculations based upon the assumption that the most corrosive water occurs when pH, alkalinity, temperature and calcium -
are at the minimums while total solids are at the maximum.
- 5. The assumptions in notes 3. and 4. above are strictly those implicit in -the calculation of the Langlier Saturation Index as a result of the inverse solubility of calcium carbor. ate with temperature. We are specifically not stating that corrosion rates are inversely related to temperature. .
i l
r- -,e -
Thorrns M. l.cuonge, Inc.
1U439 N.E. FOURTH PLAIN ROAD e P.o. 80X 4448 e VANCOUVER. WASHINGTON 96662 e (206)254 1213
[
January 19, 1981
\
5:
.2 V ARKANSAS POWER & LIGHT COMPANY P. O. Box 551 Little Rock, Arkansas 72203 e+
Attention: Mr. Dan H. Williams, Generic Projects Coordinator i
SUBJECT:
RECOMMENDATIONS FOR THE SERVICE WATER SYSTEtts
- ARKANSAS NUCLEAR ONE - UNITS 1 & 2 -
AP&L CONTRACT NO. L-020G, TASK NO. 001P, PLANT ANO W T.M.L. PROJECT NO. 032-01-001 n
Dear Mr. Williams,
[- Attached to this letter please find fifteen (15) copies of our report titled in subject. If you need other copies, kindly let us know.
You will note that we retained the original of this report so that we can
- r. reproduce this rapidly.
In the preparation of this report, we have furthered our work reported to you on December 15, 1980 and attempted to incorporate the corr.ents of yourself and your cc-workers.
We feel safe in stating that the general consersus of opinions
,O which we received on our report of December 15 was the desire that the I attached report contain as many " specifics" as is possible. In addition to attempting to be specific in this report, we trust that the organization of the material presented is readily usable.
Please let us know if you have any questions and/or if we can be of l any further assistance.
Very truly yours ,
]
t D. g g Thomas M. Laronge, l il President l ll TML:mt y.
l :j .
Enc - 15 Copies l
l n(
Quality for Industry