ML20137D557

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Discusses Corrective Program for Bearing Cooling Water & Svc Water Sys in Response to Fouling/Corrosion Problems W/Lake Anna Water.Both Sys Will Be Chemically Treated.Design Mod to Make Bearing Cooling Water Sys closed-loop Sys Planned
ML20137D557
Person / Time
Site: North Anna, 05000000
Issue date: 04/29/1977
From: Brown S
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To: Case E, Regan W
Office of Nuclear Reactor Regulation
Shared Package
ML20136A555 List: ... further results
References
FOIA-85-363 NUDOCS 8508220514
Download: ML20137D557 (12)
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April 29, 1977 . T5".". /

Mr. FAam G. Case, Acting Dired.a:

Office of Nuclear Reactor Ibgulation Serial k h ICA/JEE:krti y'/

Attention: Mr. W4114= H. Regan, Chief Envise.T.:ntal Projects Branch No. 2 Division of Site Safety and Environ-mental Analysis U. S. Nuclear Regulatory Ot==4 ==4m Docket Hos. 50.-338 m ahington, D. C. 20555 50-339 Daar Mr. Case:

During a meeting on January 11, 1977 with the NRC Staff, where the North Anna Envias .=tal 'Dechnical my 14'imtions were dia'imaad, Vepoo informed the Staff that certain changes to the Bearing cooling Water and Service mter Systes were being considered. He had discovered a fouling and corrosion problem due to the high iron content, the presence of sulfate

=deing bacteria, and the general corrosive nature of the lake water. An engineering design change has been developed to arrest this fouling and corrosion in the future.

A ccu.sa.itive program was developed which consisted of two stages:

(1) the cleaning of both systems of fouling and corrosion products, and (2) chamimi treatment of the systes to prevent future fouling and corrosion.

'the design =,dii'imtion for the Bearing cooling mter System included changes from a once through systan to a closed loop with irew=d draft moling towers. 1he' towers will be located 80 feet due east of the water treatment bi41 ding. 'the dimensions of the structure are .w wdmately:

30 feet high,100 feet long, and 70 feet wide. 1he towers will have four cells, a ocmmon basin, and will service both thits 1 and 2. 'the systm will be cham 3m11y treated to inhibit the developnent of any additional fouling and corrosion.

t An interim chemical treatnant program will be instituted for the Bearing Cooling Water Syst s to retard fouling until the cooling tower is ocupleted in early 1978. One ppn of an in.u.pnic polyi A .wi A ate will be con-tinuously fed to the syst m. 1his will discharge to the thit 1 circulating water dis.harge tunnel. 1his c}==4=1 treatment will pemanently cease when the cooling towers beccme operaticnal. .

1here will be a reduction of thermal discharge to Lake Anna frce j the Bearing Cooling Water Syst m . 1he bLW will occur at a rate of 200 j gpu with a maxinun temperature of 920F and the evaporation rate will be 400 gpn. However, because of the use of cb-im1_s in this systan, the blowdown will contain scrne residue, which in the worst case will contain 10 mg/l of 1 PO4 and 0.5 ppn of free residual chlorine at a pi in the range of 6 to 8.5.

This will be diluted in the discharge tunnel by a factor of 9,000 when both i thits 1 and 2 are in operation.

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Die Service thter Systan will be cWim11y treated in the same manner as the Mring Cooling Water System. Tie naxinza him1 con ntrations in the blowdcwn are the sam for both systems. %e maxi-nun e;:pected tiowdown fzun the Service Water System is 200 gpn.

Vepm believes the net change in the total envitessital impact of station operation is insignifimnt. If you have any questions we will be pleased to answer them.

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Mr. Edson G. Case, Acting Director Serialikk3S fY Office of Nuclear Pcactor R29ulation IOVJE:kriiQ

Attentica: Mr. Willim H. Fogan, Chief .

Enviromental Projects Franch Ib. 2 Division of Site Safety and Dwiron- .

nuntal Analysis U. S. Nuclear Pogulatory Connission Docket tbs. 50-338 thshington, D. C. 20555 50-339

Dear Mr. Case:

D$ ring a rceting en January 11, 1977 with the NFC Staff, khere the North Anna Enviremental Technical Spacifications kure discussed, Vepco infor:nad the Staff that cer: sin chang 2s t.o the Bearing Ccoling Water ard Service Water Systcres were being censidered. We had disecvered a fouling and corrosien problem doe to tha high iron centenc, the. prescree of sulfato rcCucing tacteria, and tha general cerrosive nature of the lake water. An engineering design change has been developed to arrest this fouling ard corrosica in the future.

A com2ctive program was develo;cd which consisted of twa stages:

(1) the cleaning of both systems of fouling and ccrrosica prcducts, and (2) chrnical t:.catment of the syste.s to prevent future fouling and corrosion. .

b 2 design ntAl#ir-^ tion for the Bearing Ccoling thter Systm included changes frem a once thruugh systan to a closed Icep with induccd .

m2 tomrs will te located 80 feet due cast of the draft cooling toers.

kuter treat:n2nt building. Tne dirensicas of the st:rcten are approxirately:

30 feet high,100 feet long, and 70 feet wide. m3 tomrs will have fcur cells, a ccnnen basin, and will service teth thits 1 ard 2. ma systen will b2 chemically treated to inhibit tha develo;nent of any additional fculing and corrosion. -

An interim ch:nical treatrent .eu will be instituted for the B2aring C cling Water Systen to retri ::uling until the ccoling toer is ccrpleted in carly 1978. Cnc pgn of an urarganic polyphosphate will to con-tinuously fed to the systen. mis will discharga to tha Unit 1 circulating wutor discharge tunnel. mis chanical treatrent will p;=anently mm when the cooling towers becsaa op2raticnal. .

%2re will be a reducticn of the=al discharga to Iake Anna frem the Dearing Ccoling Water Systcm. e.e blowdown will cccur at a rate of 200 spn with a maxir=rn tcrp2rature of 920F and the evaporatien rate will to 400 spn. Ecu2Ver, tocause of the use of cir.micals in this system, the bicudown r will contain scnn residuo, which in th2 wcrst case will c=ntain 10 ng1 of PO 4 ard 0.5 pan of free residual chlorine at a pH in the range of 6 to 8.5.

mis will be diluted in tha clirehargo tunnel by a factor of 9,000 when both thits 1 and 2 are in cgeration.

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yngswi. Etzetac s.x3 Pows 3 CInPaxv 1. Io Case Sheet h 2 She Service Water Systen will be cWim11y treated in the saan ranner as the Ecaring Cooling Water System. Tin raxi=.:m cherical concentratiens in the blow 6.mn are the sca2 for both sys*a::s. The nuxi-sua e.'gceted bicWdcwn fran the Service Water System is 200 gpn.

Vepco believes the net change in tha total envizcc:nntal inpact '

of station c;cratica is insigr H! cant. If you have any questions we will . .

be pleased to arswer thsn.

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Attachmint C

, Feb.ruary 18, 1977

.ENGRTH ANNA {t:NVIRONMENTAL COALITION P.O. BOX 3951 Westinghouse "Under the Gun" [9F 0 9 to Solve Radioactive Leakage Says NRC l

SURRY'S E STEAM GENERATORS APONG THE WORST IN THE NATION l

Note to Reporters: This news release is longer and more detailed than usual because of the extreme importance of the topio.

NRC calls leaking steam generators at nuclear plants "a very hot issue,"

affecting the entire industry as well as Surry where the problem is ,

described as "more severe" and affects the followings l

1. Prolonged downtime for repair
2. Radiation exposure of repair personnel
3. Increased costs for repair and replacement power
4. Increased offsite radioactive gases
5. Increased offsite radioactive liquids
6. Increased radioactive waste processing
7. Increased number of solid waste shipments  :

h VEPCO's possible cancellation of reactors #3 and 4 at the Surry nuolear station may be related to the defective and leaking performance of reactors

  1. 1 and 2.

Surry's Westinghouse steam generators have been plagued with leaks since the spring of 1974, greatly increasing the release of radioactive liquid into the James River. According to Mr. Joseph Massey, VEPCO Health Physics Super-visor at North Anna, anything over "600,000 gallons a month, you could attri-bute to steam generator tube leakage."

The steam generator leakage is evident in the 1974 releases in excess of 600,000 gallons a month May.............. 285,000 gallons June............. 1,270,000 gallons July............. 2.610,000 gallons August........... 2,800,000 gallons Sept emb er. . . . . . . . 5,050,000 gallons Tube-plugging repair efforts began in 1974, and continued throughout 1976, but the problem _ remains unsolved. Burry's release of radioactive liquid the

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g. ) -l first nine months of 1976 alone we.s more than 3 irimes that of the preceding 2 years and al:sont 15 times that of 1973: ,

1973.................. 4,301,000 gallone 1974.................. 18,636,000 gallons 1975.................. 18,705,000 gallons 1976 (9 months)....... 60,980,000 gallons NUCISONICS WEEK, a major publication of the nuclear industry, has taken note Surry's leaks: "YEPCO has problems with both its Surry units - a tube in Unit I split, and according to the NRC, reached a leak rate of 80 gal / min _,

and there are indications of other cracks." 9 l Surry was also sited in the December 1976 NUCLEAR NEWS, which explains the problem this way: "The generator tubes - over 3000 in all - in this Westinghouse design are held in place by horizontal carbon steel plates, which become corroded by deposits on the tubes. The corroded steel expands and pi:1ches the tubes...resulting in leaks. At the Burry-2 plant of Virginia Electric and Power Company... denting is comparatively severe..."

h Westinghouse "Under the Onn" According to NRC/ Atlanta, leaking stess generators "are obviously a liability" for Westinghouse, and the company in "under the gun" to find a long-term solut:cn. NAEC asked NRC if utilities were considering a suit l

i j against Westinghouse for this costly defect in essential nuclear equipment.

At the moment, Westinghouse (already being sued for defaulting on fuel contracts) is researching the problem jointly with the utilities.

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h North Anna Mar Be Affected YEPCO calls the North Anna plant a " mirror image" of Surry. North Anna steam generators are also made by Westinghouse and thus may suffer from the same unsolved problem. NUCLEONICS WEEK writes that "_W is considering pre-t l

ventive plugging of suspect tubes, rather than waiting till they start leaking," probably the aim of WEXTEK process performed at North Anna.

Safety Significance of Steam Generator Tubing According to the NRC, "The steam genert tor tubing. .. represents an integral part of a major barrier against fission product release 1jo the en-vironment...The weakening of these tubes...could result in rupture of tubes and release of fluid energy from the secondary system into the containment 1.121 or reactor vessel" during a loss-of-coolant accident (LOCA). Reg. Quide On September 15, 1976 Surry Unit #2 experienced a forced shutdown from a " ruptured tube," an accident that has the potential for releasing 17,000 curies of Xenon-133. YEPCO said the tube rupture incident in-volved "no direct release of gaseous radioactivity." Nevertheless, VEPCO reports the release of 14,300 curies of Zenon-133 during the first nine months of 1976, almost twice the amount of the 2 proceding years, and in keeping with Surry's mounting difficulties.

Morton Fairtile, NRO Surry Project Manager, called steam generator defoote "one of the biggest problems we have today." The problem, he told The Frederiokaburg FREE LANOE STAR, is seriously affecting four reacters in the United States. "Unfortunately," he added, "two of them are in your service ares."

h Steam Generator Leaks are " Expensive Occurrences" The " forced shutdown" of Surry $2 on September 15 with a ruptured steam generator tube meant over 3 months of downtime for repairs, at a cost of c. $9,000,000 per month for replacement power alone.

(The total out of service time for Burry $1 and 2 in 1976 for steam generator and other problems was 288 days, (#1:114, #2:174) putting replace-ment power oosts alone in the vicinity of $80,000,000 based on YEPCO's figure of $250,000 - $300,000 per day of downtime.)

"The high cost of replacement power and the high cost of man-rems re-ceived by repair crews make tube failures in nuclear power plants expensive

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occurrences," according to MRC's NUCLEAR SAFETY magazine of March-April,1976, which also cites Surry as suffering tube . leaking and " tube thinning" beginning in May of 1974.

The problem areas are so highly radioactive that repair men can only work a few minutes at a time before their " allowable" dosage is used up.

Recently about 50 men were recruited from North Anna to work on Surry re-pairs NAEC has been told.

Consolidated Edison's Indian Point #1 attempts at in-place repair of defective steam generator wolds "had to be abandoned due to the cramped work location and high radiation fields " according to a recent CEP report.

"The radiation field restricted the average worker's repair time to 20 minutes, including 5 minutes to crawl into and out of the repair area through radiosotive spaces." NAEC has been told that increasing areas at Surry are becoming radioactively contaminated.

hRisktoWorkersatSurry A large part of NAEC's case against North Anna operation is based upon Burry's poor record of radioactive control.

NRC testimony at the recent operating license hearing substantiated YEPCO's deficient performances (Albert F. Gibson III, Chief, Radiation Support Sectied

" Personnel exposures tg radiation h_a_v3 increased over the j

operating life of the station, due primarily tg problems

experienced _ with stea3 generators and liquid radwaste pro-l oeseing...

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" Airborne concentrations of radioactivity have been and continue tdXhigh in the contain:nent buildings due to system leakage _a_...

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" Contamination control within the plant...has been a continuing problem at Surry. ..

l l " Enforcement action has been taken in this area for failure to I

follow health physics procedures _ related to contamination control. ..

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"...two potential problems related to measuring radionotive iodine in affluents have been identified by RRC inspectors...

l "In susunary, steam generator tube leakage, high steam generator l blowdown rate, and other system leaks have increased the rate of radiosotive effluent release. particularly airborne."

At the emne hearing at which Gibson of the RRO made the foregoing statements about Surry operation, YEPCO's Massey confirmed that the main source of per-sonnel radiation exposure at Surry cane from " steam generator maintenance."

Massey also predicted that in the future " exposures are going to increaso...

because radioactivity builds up in the station."

hSolid Waste Shipsents In 1974, the Barry plant had the second highest number of solid waste shipments of any plant in the country, a total of 70: 34 to South Carolina and 36 to Kentucky. Massey testified that the number of shipments could in-dirootly be related to the steam generator tube problem at Surrys "If you are doing a lot of maintenance, you produce more waste."

The shipments included " protective clothing and other items, and 14,500 gallons of low level liquid waste..." RAEC was told recently that ,

l even the tools for steam generator repair may become so radioactive that  ;

they are discarded as solid waste.  !

gPrognosis Eeep pluaring?

Leaking steam generator tubes cannot be plugged indefinitely. NRC says that each plugging outs out flow path for coolant. Westinghouse, cited by RRC for " Design Error." now says that a "psnalty of 10 0F mnet be applied for for each 1% of steam generator tubes that are plugged." That would mean a

. penalty of 94 for Surry #2 with 9.4% of its tubes plugged.

But plugging is not a solution. Neither is replacement until the problem is, understood _ and solved. Nevertheless, replacement - costing many millions

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and over a year of downtime - is being considered. i In an NRC document entitled RETIN OF SURRY l & 2. CRACKING OF STEAM '

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GRERATOR SEISMIC RESTRAINTS, the NRC suggests that it might be wise to

' consider replacemnt of those restrainto "with a material considered to be innune to environmentally induced failure." It appears that some repairs in the supports were made after cracks were discovered in the " swivel rings" in 1974, but better material is being reconenended.

From the foregoing, it is obvious that the entire steam generator situation at Snrry is a troubling and expensive one, acocepanied by constant exposure risks for both YEPC0 personnel and for citizens in the I surrounding area.

YEPC0 news stories talk about " contained" and "on-site" releases, but VEPCO's Massey testified quite candidly at the recent hearing:

"I can't distinguish between an onsite release and offsite release...

"Our releases in the liquid path are discharged in the ciro water system which is onsite and goes offiste, so we discharge it within l the site boundar.v. but it aces to the environment.

"The esse way with gases. We have vent stacks on site which release the gas, which, of ocurse, disperses offsite."

Given the current defective operation, it is a boon to the health of Surry area residents that Units 3 and 4 will not add to their radioactive dose.

Given the extraordinary costs of repairs and replacement power, TEPCO finauces can only benefit by nuclear retrenchment, as RAE testified before the State Corporation Commission in both 1974 and 1975.

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l NORTH ANNA ENVIRONMENTAL COALITION P.O. BOX 3951 (804)282-8817 CHARLOTTESVILI.E, VIRGINIA 22903 CRACE IN CONCRETE OF FI40R OF REACTOR #3 (703) 832-3983 or (804)293-6039 FOLI4WS LINE OP FAULT FROM WALL TO WALL The following paragraphs are excerpted from the testimony of Dr. Antonio V. Segovia.

Associate Professor of Structural Geology, Engineering Geology, and Environmetal l Geology at the University of Maryland:

"A crack has developed in the concrete poured on the floor of the excavation ,

for Reactor Unit No. 3. This crack has a much greater length in orientation and l l

parsistence in orientation than norinal contraction cracks that develop on concrete as i part of the normal setting and curing. The s t . . .

cor. crete is less than a year old and was poured

. - as an unreinforced working floor...The aspect of this crack that is of interest.. .is that it fol-lows fairly closely the line that one would trace to join the traces of the fault from one wall of the excavation to the other acrces the concrete l

floor...

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I 4 "There are two interpretations for the presence of this cracks (1) Slight movenent be-

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, cause of the tectonic reactivation (because of 1 s possible implications, this should be considered a theoretical possibility at this time) or (2)

Mt. ANTONIO SE00VIA EXAMINES CRACK Slight differential movement as the result of IN CONCRETE ON FLOOR OF REACTOR #3 differential rebound of geologic materials on (Line darkened for printing) either side of the fault...

VISITOR'S CENTHI ALSO HAS CRACK

" Observations along the foundations of the visitor's center also suggest minor differen-tial settling of the building...A hairline crack has developed on the lower part of the cestern wall near the northeast corner...

"Our rapid observation of this building suggests that some uneven settling is probably taking place, with the side to the north of the shear zone probably settling slightly faster.

Ts.'s, in theory, may be caused by differential properties in the bearing capacity l of the subfousAation materials, to uneven loading, or to a slight downward movement of the north block with respect to the south block..."

The foregoing testimony was prepared for the "Show Cause" hearing on North Anna faulting.

( Attachar5*A IE. ANTONIO Y. SEGOVIA is Assoaiste Professor of Structural Geology. "

Engineering Geology, and Envirousental Geo-logy at the University of Maryland. In 1974, he visited the North Anna site to study foundation conditions, and in March of that year testified at the Show Osuse hearing on North Anna faulting impli-cations. He also raised questions about differential settling.

On May 22,1977, he wrote NAED the following in response to having read the Coalition's concerns about halloyaite in North Anna founds tions:

"It seems to me that the hearing on May Sist is probably a good I opportunity to focus some questions on the unsuitability of halloysite as foundation material for any structure expected to last for a while.

"A good reference book to start on this is:

. Principles of Engineering Geology and Geotechnics by D. P. Krynine and W. R. Judd McGraw-Hill...

l 1 1.e.: p. 136, 2nd paragraph:

"'A slaking test alware should be done if the ' soil in the structure or its foundation is likely to be attacked by water.'

"Was this done at North Annat is there a record of it?

p. 16, last 5 lines:

"'Halloysite, one of the kaolinite minerale, occurs in j round or flattened tubes. When this mineral is wet, the tubelike structure apparently acts like a pile of t

roller bearings and the mass flows or creeps.'

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. "This characteristic makes hallcysite uniquely unsuitable for embankment or foundation materials. What would happen in case of even a mild earthquake to a structure resting on water-saturated halloysite is easy to imagine, expecially for a case of non-uniformly distributed load as is probably the case in the pum@use.

"On the other hand, dewatering of this material is apt to cause differential settling, which is what appears to be occurring already, and this is probably due simply to differential loading.

" Insisting on focusing many of the . questions on the properties of halloysite will probably bring out many of the problerns likely to

< be faced in the future at the North Anna site. It does not have to I

be 100% halloyaite either. A fraction of the foundation material would be enough to cause all kinds of grief."

(Signed) A. Segovia (A copy of Dr. Segovia's complete letter of May 22, 1977 is attached.)

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