ML20079F414

Requests Authorization to Chlorinate Main Condenser Sys & Discharge Total Residual Chlorine at Up to 0.20 Mg/L from Sys as Measured at Point of Discharge to Receiving Waterway for Up to 12 H/Day.Technical Justification Encl

ML20079F414
Person / Time
Site:	Oyster Creek
Issue date:	01/04/1984
From:	Ebert R GENERAL PUBLIC UTILITIES CORP.
To:	Kurisko P NEW JERSEY, STATE OF
Shared Package
ML20079F417	List: ML20079F414 ML20079F432
References
NUDOCS 8401180259
Download: ML20079F414 (5)

Text

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GPU Nuclear g{ P.O. Box 388 Forked River, New Jersey 08731 609 693-6000 Writer's Direct Dial Number-Mr. Paul C. Kurisko, Chief D

• Industrial Waste Management Water Quality Management New Jersey Department of Environmental Protection Division of Water Resources PO Box CN-029 Trenton, NJ 08625

Subject:

GPU Nuclear Corporation (GPUN)

Oyster Creek Nuclear Generating Station (OCNGS)

NJPDES Permit NO. 000 5550 The USEPA Stean Electric Effluent Guidelines at 40 CFR 423.13(b)(2) will limit, as of July 1,1984, the discharge of total residual chlorine in once through cooling water from any single generating unit of 25 or more megawatts to ne more than two hours ,ser day unless the discharger can demon-strate that a discharge for longer duration is required for macroinverte-brate control. The OCNGS exceeds this generating capacity and operates a

- once through coollng. system for the station's main condenser and will there-fore be subject to these limitations.

The OCliGS' main condenser is divided into six sections and the station's NJPDES permit presently authorizes the chlorination of each of these six sections for up to two hours per day with not more than one section being chlorinated at a time. Therefore the permit allows for a total of twelve hours per day of chlorination of this system.

GPUN believes that this chlorination schedule is not only necessary for macroinvertebrate control of the main station condenser, but also oresents less adverse environmental impact than would simultar.eous chlort-nation of all six condenser sections. This belief is based upon the the results of a chlorine minimization study conducted at the station in 1976, macroinvertebrate fouling problems encountered at other station systems in the past and environmental evaluations conducted on the station and its various syster.s. The details concerning these areas are contained in the attachments to this letter.

Consequently, GPUN hereby requests in accordance with 40 CFR 423.13 (b)(2) authori:ation to chlorinate the main condenser system and )

discharge Total Resicaal Chlorine at up to 0.20 mg/l from this system as l

I 8401180259 040104 DR ADOCK 05000 l \

G:J N.:;ea is a can of tre Generat Pubhc Utitities System

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! measured at the point cf cis:harge t; the receiving waterway for up to

! twelve hours per day on a sc.edule :nat would limit chlorination of each of

! the six condenser sections t: nc core than two hours of chlorination per day with no two sections being c..1:rir.ated simultaneously. Such authorization is requested te continue heyer.d the July 1,1984 statuatory deadline and remain in effect for the term of :ne !!PDES permit and subsequent permit renewals.

If you have any questiens regarding this request or the attached ,

!' informatior., please contac: !!r. Ronald Lacey, Manager Environmental l Licensing at (201) 299-2271 or our Corporate address. l Very truly yours, AA O' e er Vice President / Director  ;

]

Oyster Creek 4

RKL: dis:0203f Enclosures

ATTACHE!TI I i

Technical Justification for Alternate Chlerination I.initatic .e Recently r.dopted Steam Electric Ef fluent 1. imitation Cuidelines (4 0 CTR 423) will recuire the Oyster Creek Station to limit the ar. cunt of 7etal Residual Chlorine (TRC) in its discharge to 0.20 mg/1, and limit the duration of TRC discharge from any single generating unit to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per day, unless the discharger can demonstrate that more than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per day is needed for macroinvertebrate control. Tnese limitations apply at the point of discharge to the receiving waters and compliance must be achieved py July 1,1984.

According to its NJPDIS permit, the Oyster Creek Station is presently authorized to discharge Free Available Chlorine (FAC) at concentrations not to exceed 0.50 mg/l maximum and 0.20 mg/l average at the outlet of each condenser section. The station is also authorized to chlorinate each of the 6 condenser sections, in secuence, for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per day, for a total of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> per day of chlcrination.

It is CPU Nuclear's contentien that the new chlorination guidelines are unnecessarily restrictive and that the present limitations, which meet the intent of the new guidelines, should be maintained for the following reasons:

1) G;U has conducted detailed studies of alternative condenser etlerination schemes, designed to determine the minimal acceptable rate of chlorination which would keep biofouling at an acceptable level while M nimizing environmental impact (Ebert. 1977, Attachment 1- A) .

With respect to the duration of chlorination, the results of these studies indicated that the chlorination of each of the six condenser sections for 6 twenty minute periods per day afforded a level of biofouling protecticn that was comparable to chlorination periods that were of 30% longer duration.

With respect to the amount of chlorine applied, the studies showed that reducing the chlorination rate from 1500 pounds per day (ppd) to 1300 ppd did not result in an observable decrease in condenser protectien. Furthermore, chlorination of each condenser section at the latter rate (1300 ppd) for 6 twenty minute periods per day, in sequential f ashion, resulted in average FAC concentrations of 0.11 mg/l (range cf 0.06-0.17) and average TRC concentrations of 0.16 mg/l (range of 0.0E-0.24) at the outlet of the condenser section. g chicrine residuals were detected at the peint of discharge to the receiving water Dody under this chlorination sche:me. Although the results cf these studies showed that this chlorination scheme proviced acceptacle levels of condenser protection and no chlorine residuals in the receiving water body, it was concluded that it might l

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5 ne pcssarle tc f;:tne: rede:e :ne a c e : cf c..1crine applied ,

pessi:1;. c as little as E:~ ppd. .:s p ;;cscphy has been applied sc :ne en.crinatien ;:ac ;ces a: Cyste: 0:eek and during the 15EC-;SE pe: icd, the ave: age daily :a e cf cnicrination has not exceeced i23 ppd.

2) Tne .cnth'.y Oischarge Menite:ing Repcr ts se:mitted to the NCDEP, Divisien cf Kate: Resocrees, clearly document the f act that the levels of TAC at the peint cf discharge to the :eceiving water body ra:ely ex:eed the lo.er limi- cf detect;en zy Ampe:cmetric Titration

( 0. 0 5 ng/.) , confirn:ng the results cf -he toove referenced s*.udy.

During the 15EG-15E2 period, tne concentratien of TAC in the condenser discharge has not exceeded 0.10 n;/1. .

3) studies cf cendenser perfornance (actual vs. design heat transfer r esistance) , alcng v:th visual inspecticns cf the condenser tubes, tube shee:s and water boxes, indicate tha t significant accumulations of ticfculing occur, primarily near the discharge side of the condenser, under the present chlorinatien scheme.

These observa-icts indicate the chicrine de:and of the system is such that at t:e p:esent rate of applica icn, the amount of free chlorine reaching :ne disena:ge side of the condense: is insufficient to provide cc:plete biciouling centrol. T. tis is not surprising given the results cf the chlcrinc ment:cring prog:a:n described above, and is an indies.tien that the p:esent level of chicrination is at or near opti .em.

4) The lack cf c-her infustrial discha:ges on Oyster Creek precludes the possibili y cf any synergistic ef fects such as the formation of chicrinated hydrccar:cns f rcm the very low concentrations of chlorine residuals discharged f rc: the statien.

E) Final confirnatien cf the innoccous level cf chlorine residuals in ,-

the discharge of the Oyster Creek Statien comes from studies of the organisms inhabiting the discha:ge canal.

Sessile : benthic invertebrates, becaese cf their limited mobility, should be most susceptible to the ef fects cf residual chlorine in the discharge water. The results of studies of the benthic invertebrate ce:manity in the disenarge canal, however , indicate the presence of a heal:ty benthic f auna. In a cc:parative study of the epibenthic f auna in :ne inta<e and disenarge canals, cenducted by the National Ma:ine Titneries Service, nc cverall d;f f erences in diversity and evenness :e:veen the twe loca:icns were detected, although some seascnal cif f erences, p:cbably : elated to the ter:perature dif f erent:a1 oe:seen tne twc locatiens, were indicated. The authors concluded tha- *no g: css detrinenta; er beneficial effects of the power plant ef fluent were f cund* (Ycung and Tra.me, 1976;),  %

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-3 The hard clan, Mercenaria cercenaria, is the most important ec mercially harvested . species in Barr.egat Bay. This species has been the subject of acuaculture experiments in the intake and discharge canals of the Oyster Creck Station since 1979. The results cf these studies show that clams grown in the heated condenser discharge gros significantly f aster than those maintained in the intake canal throughout most of the year. The only exception was when mid-sur=er water temperatures exceeded the known upper lethal temperature for this species. The results of these studies will be the subject of a report to be issued in January of 1984.

Where larger, mere mobile crganisms are concerned, although seasonal avoidance of the discharge canal was observed for some species, over the entire year, significantly greater numbers of fish and blue crabs are found in the discharge canal when compared to the intake canal.

Based on total annual catch by trawl and gill net, Tatham et. al.

(1976) reported that over 1,500 more individual fish (7,045 individuals) and 5 more species (36 species) were'found in Oyster Creek than in Fcrked River (5,501 individuals; 31 species) .

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Clearly then, the chlorine limitations contained in the current NJFDES Permit for the Oyster Creek Station meet the intent of the new guidelines, that of protecting the environment from the detrimental impact of exces2ive chlerine residuals in the receiving waters.

References Ta tham, T. R. , D. J. Danila, D. L. Tnor.as and Associates. 1978. Ecological studies for the Oyster Creek Generating Station, progress report for the period September IS76-August 1977, volume one, fin- and shellfish. Report to Jersey Central Power and Light Company by Ichthyological Associates, Inc.

Young, J. 5. and Frame, A. B.1976. Some Effects of a Power Plant Effluent on Estuarine Epibenthic Organisms.

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