Text

Supplemental Application for Renewal of NPDES Permit NH0020338,addressing Chemical Discharge Data for Ocean Discharge Criteria Info Rept
	ML20151P600
Person / Time
Site:	Seabrook
Issue date:	08/03/1998
From:	Feigenbaum T; NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:	Devillars J, Puleo S; ENVIRONMENTAL PROTECTION AGENCY
References
	AR#97001236, NYE-98021, NUDOCS 9808120009
	Download: ML20151P600 (43)
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M North Adantic Energy Senice Corporation nOrtli P.O. Box 300 Atlaiitic Seabrook, NH 03874 (603)4749522

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ne Northeast Udlities System

. August 3,1998

[ NPDES Permit NH0020338 NYE-98021 AR#97001236 United States Environmental Protection Agency Region 1 Attn.: John P. DeVillars, Regional Administrator c/o Shelly B. Puleo, Environmental Protection Specialist

, Municipal Assistance Unit

, Office ofEcoSystem Protection John F. Kennedy Federal Building Boston, Massachusetts 02203-0001 I

i 6 Seabrook Station i

Sunnlement to NPDES Permit Renewal Aeolication j L i North Atlantic Energy Service Corporation (NAESCO) hereby submits, pursuant to 40 CFR 122.21(d), a supplement to its April 23,1998', application to renew National Pollutant Discharge Flimination System (NPDES) Permit No. NH0020338 for Seabrook Station, a nuclear electric genemting facility located in Seabrook, NH. NAESCO has opemtional responsibility for Seabrook Station and is a wholly-owned subsidiary of Northeast Utilities the parent company for the Northeast Utilities system. 'Seabroo_k Station is jointly owned by eleven New England utility companies.

This supplement to the April 23, 1998, NPDES Permit renewal application addresses the

_ following items:

' North Atlantie Energy Service Corporation lener NYE 98012, dated April 23,1998," NPDES Permit Renewal Application" Mr. Ted C. Feigenbaum (Nonh Atlantic) to Mr. John P. DeVillars 98'8120009 0 980803 k PDR ADOCK 05000443 ' I P PDR g.

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1.** ~ U.S. Environmental Protection Agency NYE.98021/ Page 2 l Chemical Discharge Data for Ocean Discharge Criteria Information Report ,

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Proposed Change to the Discharge Limit for Methoxypropylamine - ~

Proposed Change to Analytical Method for Cooling Tower Chlorine Analysis

. Proposed Use of Altemate Biocide EVAC

Chemical Discharge Data for Ocean Discharge Criteria Information Report (Enclosure 1)

The April 23,1998, renewal application included an Information Repon in partial fulfillment of the requirements of Section 403(c) of the Clean Water Act and the Ocean Discharge Criteria '

delineated in 40 CFR 125. The specific information requirements necessary to meet these statutory requirements was delineated in an EPA lener to North Atlantic dated March 4,1998,2 North Atlantic has completed the Information Report, compiling the requested data for the chemical discharges identified in the April 23,1998, renewal application. The requested data for current and future chemical discharges as well as laboratory chemicals is presented in a '

spreadsheet format in Enclosure 1. The enclosed spreadsheets specify the chemical composition for commercial chemical products, discharge frequency, annual loading, transport, fate, persistence and aquatic toxicity. In certain cases no data or limited data was available as j

indicated on the spreadsheets. Limited aquatic toxicity data was available for Hydrazine. The ;

enclosed spreadsheets cite Hydrazine toxicity testing performed by Nonheast Utilities Environmental Laboratory (NUEL), " Review of Hydrazine Aquatic Toxicity", November 1996.

The NUEL results indicate Acute No Observed Effect levels of 0.12 mg/l and 0.66 mg/l for the marine species Bay Mysid and Sheepshead Minnow respectively, ne Seabrook Station discharge limit for Hydrazine of 0.5 mg/l falls between the NUEL test values. It is imponant to !

notelhat the design of the Seabrook Station Circulating Water System discharge diffuser nozzles results in significant mixing within the ocean jet mixing zone funher diluting discharges by a factor of ten, thus a chemical with a concentration of 0.5 mg/l in the Discharge Transition Structure is reduced to a concentration of 0.05 mg/l within a shon distance of the diffuser nozzle.

Proposed Change to the Discharge Limit for Methorypropylamine (Enclosure 2)

The April 23,1998, renewal application described a planned design change that will install a Cor.densate Polishing System (CPS).~:The CPS will be placed in service to expedite secondary 4

system cleanup as necessary after a refueling or maintenance outage. Additionally, if a small condenser tube leak occurs during plant operation causing seawater leakage into the plant's secondary system, the CPS will be placed in service to remove seawater contaminants while the

. leak is located and isolated. In support of CPS operation, Nonh Atlantic is proposing an increase in the maximum discharge concentration for Methoxypropylamine (MPA) from the current limit of 0.5 ppm to 2.5 ppm. The proposed increase in the MPA discharge concentration limit will

EPA lener dated March 4,1998, *1nfonnation Requirements for Sections 403(c) and 316 (A and B) Documents for Seabrook Station's Pennit Renewal (NPDES Permit No. NH0020338)," Mr. F. B. Gay (EPA) to Mr. J. Han (Nonh Atlantic).

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]', NYE-98021/ Page 3 4

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significantly increase ~ CPS operational flexibility and may aven a plant shutdown durinI l -

condenser tube leak events. The proposed limit is supported by aquatic tosicity data f5Tinarine j species which demonstrates that the aquatic community will not be impacted. Nonh Atlantic has i {

described this proposed change and has provided supponing toxicity information in Enclosure 2. i 4

I Proposed Change to Analytical Method for Cooling Tower Chlorine Analysis (Enclosure 3) '

i Discharges from the Seabrook Station Cooling Tower (Outfall 027) are subject to the effluent limitations and monitoring requirements specified in the NPDES Permit. Free Available Chlorine, pH and flow are the parameters required to be monitored for Outfall 027. North Atlantic is proposing to revise the NPDES Pennit to change the cunent requirement for Free j

Available Chlorine analysis to Total Residual Chlorine analysis. Nonh Atlantic has described

this proposed change and has provided supponing information in Enclosure 3.

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j Proposed Use of Alternate Biocide EVAC *(Enclosure 4) i i

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Nonh Atlantic requested EPA approval on July 20,1998, to demonstrate the feasibility of using an alternative to sodium hypochlorite (chlorine) for the control of macrofouling in the cooling i

water system at Seabrook Station. The proposed feasibility study is designed to assess the ability of the molluscicide, EVAC *, to control the growth of mussels and bamacles at Seabrook Station. Although the EPA approval for the feasibility study is still pending, Nonh Atlantic has provided herein in Enclosure 4 funher information and proposed NPDES Permit changes in suppon of full scale use of this product. EVAC

would preclude the need for a significant percentage of the chlorine currently permitted for use as a biocide. It is estimated that the chloiine reduction would range from 20 % to 50 %. If the proposed feasibility study I demonstrates that this product is effective and full scale application is decided upon and ;

authorind, the environment would benefit from this reduction. ;

Questions regarding this renewal application should be directed to Mr. John B. Han, Environmental Compliance Manager, at (603) 773-7762. ,

, Very truly yours, NORTH ATLAF ENERGY SE ICE CORP.

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C. Feig6ibaum .

Executive Vice Presi t

[ i and ChiefNuclear Officer -

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,. . . U.S. Environmental Protection Agency J

g NYE-98021/ Page 4 cc:

s-Document Control Desk ,

U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 :

Mr. J. T. Harrison, Project Manager Project Directorate 1-3 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Mr. Hubert J. Miller

- Regional Administrator- Region i U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. George C. Berlandi, P.E.

Sanitary Engineer Surface Water Quality Bureau NH Department of Environmental Services Water Supply and Pollution Control Div.

64 Nonh Main Street,3rd Floor Cone'ord NH 03301 ,

Marcia A. Brown Thunberg, Anomey Federal Consistency Coordinator -

NH Coastal Program Office of State Planning State ofNew Hampshire i 21/2 Beacon Street _

j Concord, NH 03301-4497 i 1

Mr.Jeffrey Andrews

. NH Dept. Of Emironmental Services Water Division 6 Hazen Drive Concord,NH 03302

Certification pursuant to 40 CFR 122.22(d)

I certify under penalty of law that this document and all attac'.anents were prepared under my diroction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible fee gathering the information, the information submitted is, to the best of my )mowledge and belief, true, accurate, and complete. I ware thTth re are significant penalties for submitting false infonnation, including the sibility of fine imprisonment for knowing violations.

N /G6' A04 W Bruce L. Dstsvbridge Date/ '

Director - Services STATE OF NEW HAMPSHIRE Rockingham, ss. Date: August 3,1998 Then personally appeared before me, the above-named Bruce L. Drawbridge, Director - I

< Services, North Atlantic Energy Service Corporation, that he is duly authorized to execute and j file the foregoing information in the name and on the behalf of North Atlantic Energy Service 1 Corporatisn and that the statements therein are true to the best of his knowledge and belief.

Suss J. Mehc( Notary Public My Commission Expires: December 22,1998

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ENCLOSURE I TO NYE-98021 n

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Commercial Chemicals Currently Discharged l

Chemicals Proposed for Discharge I Laboratory Chemicals Routinely Discharect ~~

The April 23, 1998, NPDES Permit renewal application included an Information Repon in panial fulfillment of the requirements of Section 403(c) of.the Clean Water Act and the Ocean Discharge Criteria delineated in 40 CFR 125. The specide information requirements necessa to meet these statuton requiiements was delineated in an EPA letter to North Atlantic dated March 4,1998.

The specific data requested by the EPA for chemicals which are currently discharged from Seabrook Station and for those that may, be discharged in the ft.ture was as follows: ,

e chemical composition for commercial chemical products e discharge frequency e annual loading i

e transport e fate e persistence e aquatic toxicity The April 23,1998, NPDES Permit renewal application specines chemicals currently used in Seabrook Station systems which have the potential to be present in each of the permitted outfalls.

Additionally, new chemicals which may be used in Seabrook Station systems during the term of the permit were also identified in the renewal application. For aose current and future chemicals identified, the data requested by the EPA is provided in this enclosure. Additionally, the April 23,1998, NPDES Permit renewal application did not specifically identify laboratory chemicals discharged in conjunction with laboraton analyses. This enclosure identifies the highest discharge concentration laboratory chemicals and provides the data requested by the EPA for these chemicals.

The enclosed spreadsheets specify the chemical composition for commercial chemical products, discharge frequency, annual loading, transport, fate, persistence and aquatic toxicity. nree sets of spreadsheets are enclosed addressing: (1) commercial chemicals currently discharged (Table 1), (2) chemicals proposed for discharge (Table 2), and (3) laboratory vemicals routinely discharged (Table 3). Sources used for aquatic toxicity data include: (1) manufacturers Material Safety Data Sheets and other documented toxicity data,(2) EPA Aguire Database, (3) Northeast Utilities Environmental Laboratory, and (4) Internet searches. In certain cases no aquatic toxicity data was available as indicated on the spreadsheets.

Annual Loadine Calculations The annual loading calculations below utilize actual Seabrook Station data (flow, etc.) for the year July 1997 through June 1998. His one year period, which included approximately 60 days of maintenance outage time, is representative for purposes of calculating annual loading from Page1of13

i Seabrook Station chemical discharges. During this period, the Steam Generator Blowdown

. Recovery System operated normally,its function being the cleanup and recycling of secondary

. syncia water and minimization of secondary water discharge to the Circulating Water Sy. stem.

t Abbreviations used below ana in the attached spreadsheets: '

System Desienations:

WHUS Waste Hold Up Sump (025C) :

WTT Waste Test Tanks (025D)

TBS Turbine Building Sump (022)

WT Water Treatment Plant Drains (001)

CW - Circulating Water (001) '

SB Steam Generator Blowdown (025A) < '

nischarme Freauency:

C Continuous B Batch Transnort:

1 Insolouble S Soluble (easily dispersed)

V Volatile i

fatti D Bindegradable CD Chemical reaction / decomposition in the environment NT - Naturally occurs in the environment NB Non biodegrcdable ND No Data Persistence:

A Bioaccumulates NA Does not Bioaccumulate ND No Data Tonleirv:

ANOEL Acute No Observed Effect Level NOEC No Observed Effects Concentration Page 2 of 13 <

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The assignments for transport, fate and persistence are based on information found in MSDSs for the individual materials or on solubility and chemical characteristics as found in the Handbook of Chemistry and Physics. -

Annual Loadine for Commercial Chemicals Currently Dischareed:

1. ETA Ethanolamine is used as a corrosion inhibitor in the secondary system. Annual use of ETA is 11 drums. It is assumed that the decomposition of ETA is minimal.

11 drums x 55 gal / drum x 0.40 (weight fraction) x 0.98 (sp gravity) x 8.34 lbs/ gal -

= 1978 lbs/yr 1

2. MPA Methoxypropylt. . ine is used as a corrosion inhibitor in the secondary system. Annual use of MPA is !I drums. It is assumed that decomposition of MPA is minimal.

11 drums x 55 gal / drum x 0.60 (weight fraction) x 0.97 (sp Gravity) x 8.34 lbs/ gal l

= 2937 lbs/yr

3. Dilsopropylamine(DIPA)

Sodium analyzers are used to monitor seawater or cooling water inleakage into the plant. DIPA is the principal reagent that the sodium anlayzers use to determine the sodium concentration.

Annual use is $2 bottles. The discharge is directly to the Circulating Water System through the Turbine Building Sump, the Water Treatment System drains and the Waste Holdup Sump. DIPA is also processed through Chem Nuclear demineralizer skid from CP-166B to the Waste Test Tank.

52 bottles x 1 liter / bottle x 0.72 kg/l x 2.21bs/kg

= 82 lbs/yr

4. Silica Analyzer Reagents Silica analyzers monitor the level of silica in the effluent of the Water Treatment System and Steam Generator Blowdown demineralizers. Silica is a contaminant which provides an early indication that replacement or regeneration of demineralizers is required.

A. Molybdate-3 reagent Annual use is 6 bottles. The discharge is directly to the Circulating Water System from the Waste lloidup Sump and Water Treatment System drains.

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l l' 6 bottles x 0.5 liter / bottle x 1.3 kg/l x 2.2 lbs/kg

= 8.58 lbs/yr i B. Citric Acid i t

{ Annual use is 6 bottles. Discharge is directly to the Circulating Water System from the 1

Waste Holdup Sump and Water Treatment System drains.

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6 bottles x 2.9 liter / bottle x 1.1 Kg/L x 0.2 (weight fraction) x 2.2 lb/Kg

= 8.42 lbs/yr i

5. Chlorine (as TRO) (

Sodium hypochlorite is added to the Circulating Water System to prevent both macro and micro i fouling of the system. Strategic application of the chlorine is used over the course of the year based on condenser efficiency (a measure of tube fouling). In response to NRC Generic Letter 1 8913 North Atlantic committed to chlorination of the Service Water System on a continuous basis to avoid fouling in this safety-related system. This is achieved through selective

- introduction of chlorine to the Service Water System. '

The total volume of 15% NaOCl used for the year is 619,381 gallons. The actual amount discharged is significantly less than that due to the reduction of TRO by the chlorine demand of l seawater. A :, mall volume of water with TRO is released through discharge point 027 (Cooling Tower) but this is negligible compared to the values for the CW chlorination identified below.

The annual loading is calculated by multiplying the average monthly Circulating Water System flow by the average monthly TRO and converting to lbs.

r Meath Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 98 98 98 98 98 98 97 97 97 97 97 97 Flow, 635 SM 571 580 669 417 M2 674 672 673 M6 M9 NCD TRO 0.0 0.0 0.0 0.0 - 0.05 0.037 0.0 0 03 0.06 0.02 0 03 0 03 Coev. 2.5s 2.33 2.58 2.50 2.5s 2.50 2.58 2.50 2.50 2.58 2.50 2.58 Facter E+2 E+2 E+2 E+2 'E+2 E+2 E+2 E+2 E+2 E+2 E+2 E+2 Toadme 0 0 0 0 8 63 3 s6 0.0 5.06 1.01 3 47 5.0 5.19 E+3 E+3 E+3 E+4 E+3 E+3 E+3 Total for the year = 4.13 E+4 lbs i

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6. Hydrazine in Steam Generator Blowdown Hydrazine is used as an oxygen scavenger in the secondary system and also.in threcof th.cplant's closed cooling water systems. Hydrazine is discharged to the Circulating Water System through Steam Generator Blowdown (025A), the Waste Holdup Sump (025C), or by drainage of system 4

components for maintenance. The assumed concentration of hydrazine in Steam Generator Blowdown is 0.04 mg/ liter (~ 40 ppb).

I Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 4

98 98 98 98 98 98 97 97 97 97 97 97 i Flow. 4.51 3.70 1.84 4.70 1.84E 1.22E I.40 4.39 4.97 1.70 9.45 1.08 Ist/mo ES ES E5 E5 5 +5 E5 E5 E5 E6 E5 E5 Factor 3.33 3.33 3.33 E 3.33 3.33 3.33 3.33 3.33 3.33 3.33 3.33 3.33

. E7 E7 7 E7 E7 E7 E7 E7 E7 E7 E7 E7

Lbs/ 1.5 1.23 6.13 1.57 6.13 E 4.07E 4.65 1.46 i 1.66 5.67 3.15 3.59E month E1 El E2 El 2 2 E2 El i E1 E-l El -2 i

f Total for the year - 1.87 lbs i

! 7. Hydrazine in Steam Generator Waste Holdup Sump

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Assume 16 mg/l (from a bed run of 18 days, at 168 gpm and a blowdown concentration of 0.04 0.06 mg/l as above)in the sump volume of 20,000 gallons from a cation bed regeneration. The

! cation beds are regenerated 2 for 1 for the mixed beds. The hydrazine concentration from a i

mixed bed regeneration would be zero. Therefore, the average concentration from a sump discharge would be (2/3) 16 = 10.7 mg/1.

Month I/98 2S8 3/98 4S8 568 668 7S7 8/97 967 10S 7 1167 12S 7 Flow. 1.92 3.79 5.46 6.37 1.42E I.09 6.08 5.55E 6.72 7.27 6.86 1.39 get/me E4 E4 E4 E4 4 E+4 E4 4? E4 E4 E4 E4 Factor 8.91 8.91 8.91 8 91 8.91 8.91 8 91E 8.9 t E 8 9tE 8.91 8.91 8.91

E5 E5 E5 E5 E5 E5 5 5 5 E-5 E5 E5 Total. 1,71 3.38 4.86 5 68 1.27 0 97 5 42 4.95 5 99 6 48 6.11 1.24 lb/mo ..

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Total for the year = 48.1 lbs 4

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8. Ammonia in Steam Generator Blowdown Ammonia is not added as a chemical during normal plant operation. Ammonia-is a decomposition product of hydrazine. The average concentration for ammonia in steam generator blowdown is approximately 600 ppb (0.6 ppm). During refueling and planned maintenance outages, two 6- gallon containers of 30% ammonia are used (total of 14 lbs), for wet lay-up of steam generators. The calculations below account for the discharge through steam generator l blowdown during normal power operation. The final value on the spreadsheet includes the value - I from the outage discharge.

Month Jan Feb Mar Apr. May Jun Jul Aug Sep Oct Nov Dec 98 98 98 98 98 98 .97 97 97 97 97 97 Flow, 4.51 3.70 1.84 4.70 1.84 1.22 1.40 4.39 4.97 1.70 9.45 1.08 gaVmo E5 E5 E5 E5 E5 E+5 E5 E5 ES E6 E5 E5 Factor 5.0E-6 5.0E-6 5.0E-6 5.0E-6 5.0E-6 5.0E-6 5.0E-6 5.0E-6 5.0E-6 5.0E-6 5.0E- 5.0E-6 6

Lbs / 2.25 1.85 0.92 2.35 0.92 0.61 0.7 2.2 2.49 8.5 4.73 0.54 month Total for the year = 28.1 lbs + 27 lbs for wet lay up = 55.1 lbs ,

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9. Ammonia in Waste Holdup Sump The ammonia is removed from the blowdown liquid when it is processed through the cation demineralizer resin. Assume a concentration of ~131 ppm (from a cation bed run of 18 days at i 168 ppm and an ammonia concentration in SB as in 8.) in the sump volume which is discharged.

l The cation beds are regenerated 2 for 1 for the mixed beds. The ammonia concentration from a mixed bed regeneration would be zero. The average concentration from a sump discharge is (2/3)131 = 87.3 mg/1. ,

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l Month _ l l 1/98 2/98 3/98 4/98 5/98 6/98 7/97 8/97 9/97 10/97 11/97 12/97 Flow, 1.92 3.79 5.46 6.37 1.42E 1.09 6.08 5.55E 6.72 7.27 6.86 1.39 gal /mo E4 E4 E4 E4 4 , E4 E4 4 E4 E4 E4 E4 Factor 7.40 7.40 7.40 7.40 7.40 7.40 7.40 7.40 7.40 7.40 7.40 7.40 E-4 E-4 E-4 E-4 E-4 E-4 E-4 E-4 E-4 E-4 E-4 E-4 l

! total, 14.3 28 40.4 47.1 10.5 8.07 44.8 41 49.7 53.8 50.8 10.3 Ib/mo l l !

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f Total for the year = 398.8 lbs l l l

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10. Ammonia in the Turbine Building Sump Ammonia is a decomposition product of hydrazine and is r'emoved from the secondary;ystem through the condenser air evacuation system. The water / ammonia mixture is drained to the turbine building sump and is then directed through Oil / Water Separator Vault #1 (Outfall 022).

While operating at 100% power, samples were taken frorp Vault #1 discharge and found to contain ~84 ppm ammonia. '

Month 1/98 2/98 3/98 4/98 5/98 6/98 7/97 8/97 9/97 10/97 11/97 12/97 flow. 4.96E 580E 7.32 E I.48E 4 96E 4.56 502E 54E+ 1.16E 5.67 5.73 3.5E+5 ssVmo +5 +5 +5 +6 +5 E+5 +5 +6

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5 E+5 E+5 factor 6.99E 6.99 6 99 6 99 6 99E 6 99E 6 99E 6.99E 6 99E 6 99 l 6 99 6 99

-4 E-4 E-4 T.-4 -4 -4 -4 4 4 E-4 E-4 E-4 total, 347 405 Sil '1034 347 319 351 377 807 225 400 245 lb/mo Total for the year = 5368 lbs

11. Baron in Waste Test Tanks !

Boron is added as boric acid in primary plant systems as a neutron control agent. All primary systems drain throt gh the floor drain system, through the Chem Nuclear demineralizer skid and then to the Waste Test Tank prior to discharge. Boron analysis is done on each Waste Test Tank discharge. The naturally occunring concentration of boron in seawater is 45 ppm, the current discharge limit is 5 ppm.

Month 1/98 2/98 3/98 4/98 5/98 6/98 7/97 8/97 9/97 10/97 11/97 12/97 Lbumo 324 1249 1229 155 298 34 810 186 397 335 42 142 Total for the year = 5201 lbs

12. flydrogen Peroxide Hydrogen Peroxide is normally added to the Reactor Coolant System during shutdowns, or may be used to remove radionuclides from floor drains. The discharge is through the Chem Nuclear demineralizer skid to the Waste Test Tank.

4 bottles x 4 liter / bottle x 0.3 (weight fraction) x 2.2 lbs/Kg

= 10.6 lbs / year Page 7 of 13

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13. Lithium liydroxide Lithium Hydroxide is used for pH control in the primar/ system. The discharge is thrqugh Chem Nuclear demineralizer skid to the Waste Test Tank.

2 containers x 10,200 g/ container x .0022 lbs/g

= 44.8 lbs/ year

14. DC-135 (Floor Cleaner)

DC-13 is used as a floor cleaning material / decontamination agent. The discharge is primarily through the Chem Nuclear demineralizer skid where a significant portion of this material is removed by the demineralizer resins. A small amount of this product (conservatively estimated at 10 % for this annual loading calculation) is discharged directly to the Circulating Water System.

2 containers /yr x 55 gal /contamer x 8.34 lbs/ gal x 1.04 (sp gravity) x 0.1

= 95.4 lbs/yr I

15. Sodium Hydroxide l

Sodium Hydroxide is used for regeneration of blowdown anion demineralizers. He discharge to the Circulating Water System is from the Waste Holdup Sump.

1,000 gal /yr x 1.5 (sp gravity) x 8.34 lb/ gal x 0.5 (weight fraction)

= 6255 lbs/yr s

16. Sulfuric Acid l

Sulfuric Acid is used for regeneration of blowdown cation demineralizers. The discharge to the Circulating Water System is from the Waste Holdup Sump.

1,000 gallyr x 1.82 (sp gravity) x 8.34 lb/ gal x 0.96 (weight fraction)

= 14,572 lbs/yr ,,

17. Cat Floc L. Cat Floc TL, and Flocon Cat Floc L, Cat. Floc TL and Flocon are coagulants /flocculants that have been used for processing ofliquid radioactive waste. Currently these products are not in use and have not been used for two years. However if the nature of the liquid radioactive waste material were to change it may be necessary to resume their use. It is estimated that when these products were in use the amounts discharged over the course of a year would be approximately 20- 30 pounds.

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18. Nalcolyte 7134 Nalcolyte 7134 is currently being used as a coagulant / flocculant in the radioact processing system.

It is injected upstream of a carbon filtration unit and demineralizers. A significant portion of this material (upwards of 50%) is removed in this processing a discharged.

follows, The exact amount cannot be determined, however a conservative estimate p

6 liters /yr x 9.57 lb/ gal x 0.265 gal /L g

= 15.2 lbs/yr

19. Hypersperse Hypersperse is used as a flocculant in the processing of raw water to make demineralized While the water treatment plant is in operation this material is part of the continuou stream that is discharged directly to the Circulating Water System 2 drums /yr 55 gal / drum x 1.13 (sp gravity) x 8.34 lb/ gal x 0.35 (weight fraction)

= 363 lbs/yr

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20. Muriatic acid 1 This material (also known as hydrochloric acid) is used in the processing of raw water to m!;

demineralized water. While the water treatment plant is in operation this material is par I continuous reject stream that is discharged directly to the Circulating Water System.

I 1 drum /yr x 55 gal / drum x 1.19 (sp gravity) x 8.34 lb/ gal x 0.37 (weight fraction)

= 202 lbs/yr

21. Lysol Cleaner Lysol is used for disinfecting sanitary floors and drains. The majority of this product is discharged to the Town of Seabrook Wastewater Treatnent Facility however a small amount (conservatively estimated at 10 % for this annual loading calculation) is discharged to the Circulating Water System. The total quantity discharged per year is estimated as:

8 Gal / year x 8.34 lb/ gal x 0.1

= 6.67 lbs/ year Page 9 of 13

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22. Lestoil Cleaner Lestoil is used as floor cleaner / disinfectant in various plant locations._The majority.of this product is discharged to the Town of Seabrook Wastewater Treatment Facility however a small amount (conservatively estimated at 10 % for this annual loading calculation) is discharged to the Circulating Water System. The total quantity discharged per year is estimated as:

103 gal / year x 8.34 lb/ gal x 0.1

= 85.9 lbs/ year

23. Corrosion Inhibitor Liquid (CIL)

CIL is a sodium silicate solution used to inhibit scale growth in the Cooling Tower (Outfall 027).

Discharges from the Cooling Tower to the Circulating Water System are performed approximately monthly when the Cooling Tower pumps are tested. The total quantity discharged i per year is estimated as: j 55 gal / year x 8.34 lb/ gal x 1.40 x 0.4 ( weight fraction)

= 257 lbs/yr

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! 24. Aqueous Fire Fighting Foam (AFFF)

AFFF is used for training on site fire response personnel. Administrative controls are used to 1 minimize the potential for introduction of this product into the Stonn Drain System (Outfall 002B), however for this annual loading calculation it is conservatively estimated that 10 % of this product enters the Storm Drain System and is subsequently discharged to the Circulating

, Water System. The total quantity discharged per year is estimated as:

l 6 containers x 5 gal / container x 8.34 lb / gal x 0.1 ;

= 25 lbs/ year

25. Sodium Bisulfite This material is used to eliminate chlorine when chlorine is used to clean the reverse osmosis l unit membranes of the water treatmeniplant. To date, these membranes have not needed to be

c. leaned. Thus there has been no discharge of this material. No discharge is expected in the near l 4

future.

4 Annual Leadine for Chemiests Proposed for Discharre: J The chemicals listed in this section are currently not in use at Seabrook Station. Several of them are in use at other power plants as indicated in the discussions below. The estimated annual l loadings for these chemicals is based on the assumptions, stated for each chemical. These ;

4 assumptions are made with the best available information that is currently available to North !

Atlantic and may need to be revised based on specific system performance.

Page 10 of 13 l

-. . , _ . _ _ _ .__.___..__.__,_._-.._.____..._m . _ _ _ . . _ _ _ . . _

3. Dimethylamine (DMA) 3 DMA is a pH and corrosion control agent used in the secondary system. It is not in use at any plant that we know of at the current time. Assuming the same molar fraction of DMA would be used as MPA the value for this chemical would be:

o

[ lbs MPNyear][ Molecular Weight DMA/ Molecular Weight MPA]

=[2937][45/90) = 1469 lbs DMA

2. 5 Aminopentanol(5-AP) 5-AP is a pH and corrosion control agent used in the secondary system. It is not in use at any plant that we know of at the current time. Assuming the same molar fraction of 5-AP as MPA the value for this chemical would be: .

i

[ lbs MPNyear][ Molecular Weight 5 AP/ Molecular Weight MPA] j

= [2937 lbs][103/90] = 3361 tbs 5 AP 4

3. 2-Amino,2-methyl propanol (AMP)

AMP is a pH and corrosion control agent used in the secondary system. It is not in use at any plant that we know of at the current time. Assuming the same molar fraction of AMP as MPA :

the value for this chemical would be: I o

1

[Ibs MPNyear1[ Molecular Weight AMP / Molecular Weight MPA) '

= [2937 lbs)[89/90] = 2904 lbs AMP

4. 3-Hydroxyquinuclidine(3 HQ) i 3-HQ is a pH and corrosion control agent used in the secondary system. It is not in use at any ;

plant that we know of at the current time. Assuming the same molar fraction of 3 HQ as MPA I the value for this chemical would be: ,

1

[lbs MPNyear][ Molecular Weight 3 HQ/ Molecular Weight MPAj i

= [2937 lbs)(125/90] = 4080 lbs 3 HQ

)

ti. P> rrolidine Pyrrolidine is a pH and corrosion control agent used in the secondary system. It will be in use at 3

the Diablo Canyon Nuclear Power Plant (DCNPP) in fall of 1998, and has been approved for Jischarge by EPA Region IX. Assuming the same molar fraction of pyrrolidine as MPA the ;

value for this chemical would be:

Page 11 of 13 i

[ lbs MPA/ year l[ Molecular Weight pyrrolidine / Molecular Weight MPA]

i

= [2937lbs)[71/90] = 2317lbs pyrrolidine i

6. Carbohydrazide (CHz)

.. r

)

CHz is an oxygen scavenging agent which has been used as a substitute for hydrazine, it was j- used at Palo Verde Nuclear Generating station (Arizona Power a.,d Light) and Byron Station

l. (Commonwealth Edison, IL), for wet lay-up of their steam generators. n h currently being used at V.C. Summer Nuclear Power Plant (South Carolina Electric & Gas), in place of hydrazine

[ during their normal operating cycle, and is planning on being used at Millstor:: 11. Based on the amount of hydrazine discharged from Seabrook Statiori the total arount of CHz discharged would be about 20 pounds per year. I

7. Diethylhydroxylamine(DEHA) I DEHA is an oxygen scavenging agent which has been used as a substitute for hydrazine. It has j been used at Ontario Hydro in Quebec in a pilot study and is awaiting final approval from Canadian environmental omeials. It has also been used in a pilot test at Comanche Peak (Texas Utilities). Based on an equivalent concentration used in the secondary system as hydrazine, about 20 pounds per of DEHA would be discharged. l i

t

8. Tetrapotassium 1-hydroxyethylidene-1,1 diphosphonate (Thruguard 300) nruguard 300 would be used as a scale inhibitor in the chlorination system. In 1997, Seabrook Station received approval from EPA to perform a chemical cleaning of the chlorination system

)

piping due to a heavy deposition of calcium carbonate scale accompanying sodium hypochlorite <

. addition. Although the cleaning was successful at restoring system perfonnance,' avoiding the scale build-up would obviate the use of concentrated acids. He T1uuguard is added at a concentration that complexes with calcium so that at the pH in the chlorination line the calcium does not deposit as a scale. He application of this compound would likely take place during the i highest chlorine add.; tion months (typically May to October), ne estimated usage of this ,

materialis: !

13 gpd x 8.34 lb/ gal x 0.35 (weight fraction) x 1.4 (density) x 180 days

= 9,563 lbs per year !

9. Didecyldimethylammonium chloride (H-130M)

His material would be used specifically as a molluscicide, with batch application during the mussel fouling season. Current estimates are for two applications which would correspond to an 3 annual usage of: i 2400 gal / application x 2 applications per year x 8.3.4 x 1.044(density) x 0.5 (weight I fraction) i

= 20,897 pounds per year ne amount actually discharged would be less than this due to the material's degradation over the 4-6 bour transit time in the Circulating Water System /

l Page 12 of 13 I e

?

y.

10. EVACS 1

i i EVAC is used as a molluscicide, ~with' batch application during the mussel fouling,.scason. t l

- Current estimates are for two applications. Estimated annual usage is: 1 i .l 2400 gal / application x 2 applications per year x 8.34 x 1.044 (density) x 0.5 (weight fraction) )

= 20,897 pounds per yen ne amount actually discharged would be less than this due to the material's degradation over the 4 6 hour6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months transit time in the Circulating Water System. i J

Laboratory Chemiests Routinelv Discharsted: N ;

n ne laboratory chemicals identified on the attached spreadgheet (Table 3) are those which are;(1) discharged in concentrations of >l ppb, (2) identified as toxic materials (per NHDES or EPA),

or (3) those which may pose potential toxicity (e.g. formaldehyde). .nis list does not include ;

. those laboratory acids and bases which are disposed ofin laboratory sinks and neutralized in our hold-up tanks prior to ultimate discharge. _ These acids and bases are discharged pursuant to a l

. Hazardous Waste Limited Permit issued by the State of New Hampshire Department of !

- Environmental Services. Laboratory chemical use may be subject to change in the future should !

new instruments or procedures be required for required analyses. De attached spreadsheet identifies the deminimus discharge concentrations for laboratory chemicals. .

i I

During normal plant operation, three circulating water pumps and two service water pumps are in service, providing a total flow of approximately 400,000 gpm (assumes a portion of the cooling water is recirculated through the main condensers to optimize plant efficiency during periods of reduled ocean water temperatures. During periods when,there is no recirculation the cooling water flow is approximately 450,000 to 470,000 gpm). For purposes of calculating the discharge concentrations of laboratory chemicals, a conservative flo'w value is used which assumes two circulating water pumps and two service water pumps are operating. Plant outages will typically have one circulating and two service water pumps in service, nese outages are scheduled every 18 months for a period of 30 50 days. During these periods the laboratory chemical analysis activity is greatly reduced and thus the levels of chemicals discharged from the laboratory through plant systems is also reduced. A similar situation exists for unplanned outages.

1, f

I Page 13 of 13

l TA8(I 1 COMMERCIAL CHEMICALS CURRENTLY DISCHARGED

.~

~

==paa 6,

Annual M nhW; Ceaussentes Cheadcol CeaunentalCma Dencherge Leseig 3 MM, .Sheepehead{

ireso mosmo Compeeseen Fregmency Reefyear Transpost Fsee Perstatence a wm . s- ' h TC- Reeerence Po led 7000 Emanoennee (40%) C and 9 f6me) 1978 S CD NA 412f(98IW)3'99 *Ie Nw "W 8." We naarweemrer MSDScanon Pse fed M00 Arm, (60%) C and B (6me) 2931 S CD NA '57,05)(9t hr)3 84lhs4PW":Cu Pti%" **.* Manusacturer MSDS {agon Scavon Hydratme (35%) B (6mm) 49 9 S CD NA '

1 T, CA8 (ANOEL), NU EnvoonmentalLatereeory Report ,

J f.90 (96 lu)g,* (1996). Larval Red Abelone 6 ppb NOU Dueso Canyon Nudear Plant Report j.p'

.t t!

M 1.% W- (12/96)

Am Ancen s Anwnonis C and B (6me) 5622 S NT NA 42A7PEhr)We 9dettaNtarf4 T . ,. w'ea Be Soeum Hypoderne (15%) C 41.300 $ CD NA 6 BWpynF pes %- P* W No dat evadme I peortoof Eeytene Gayal(95%) No ineontonsi 0 $ D NA Y v No deu evesse Op 5 S

NT

=

NA IRM Str## is WWFWpGeS WhppJcW 9 -a wv .

ItC>t (2%)

1121 DC 13* Idenner) C 95 4 6 4 4 huR3t#* @ ' AW.2m naanue actureq uSDS Spartan CW NonyFhenyt Emorytser (15%) S CD ND '5 0(30 hr)3sm 785WrttW o#- ? F ? - v '",,

EDI A (1%) S esB NA *100(481u) esp quessweir.! t .s < w. .

Cet Aod Surtactere cet acs!(20%) C 842 S CD NA 9PIDESWIWgt. StaFfngW

W e e-L-***** No data evadatde nu tusaw r 3 peagere C and B (6me) I 58 w __ _ _ N

W-wa* No data a,assee, Mosytec Acus (15%) S NT NA 6 Amamir.5% vs%3 e 44.M.

Seewn tusuases ty*ses (20%) S NT NA 6M ft W*t mv7.ev Susunc Aod(15%) S NT NA 6 vAos W 6 r-Lee ievel Soeum Rgt Omsograpytenue (100%) C and B (6me) 82 S CD ND N GW5miBPwery* terrr'*#t# No data evadable Bonc Aad Bont Aod (pwe seest 0 08% B (6me) 5201 S NT NA ,

14 24 (NOEC) m wes sawr-Procks anc masenwn sohman escruge) ; Garrese Study a amanda te (9e

~. fr) MSDS US an Hyeogen Perosee Myeopen Paramelo (30%) B (2*rr) 10 6 S CD NA 6 N Wet -*

M No data avadatie L*=um Nyeo'd* L Ipwe B (6me) 44 4 S NT NA No data evadetie Cauce Sode So8'wn Hyeomde (50%) B (1mel 6255 S NT NA i_ - _

i ._ _ @ * **% PS te3 data ovadatile S e Aod Susune Aod(96%) B (Pmo) 14572 S NT NA 6 N- *q->M No data avadable Buteb9329 B 11'18 Pel CW"e see = 0 , , _ ,

-^

. g_ , V 4 Nr.% 5- Freshwater tonery data tram Mir Peenssum Hyeomde (15%) S NT NA 6 - ,, T S fW S -.- e G Ebege Stefish 770 (96 M PhoecNmsees (30%) S CD ND --m SpIh3estP)GJ w ?

u t."*,'?

Rareo= Trout >1000 (96 hr)

"W h moosymer(15%) i NB ND . ., SERESIP48tN & ".W P*y 1 rif 7

TABLE 1 COMMERCIAL CHERNCALS CURRENTLY OfSCHARGED

-~

Agumas enkny. Deen: Lcm in ppm,*,

Wtehn fothc--

e m so02 e tuit nc) e ,w eune .O S CD No g : MsDseucwen TJ 7-,C, . , terre #emo) appenne eneeyenee soyen.

edewee tec%)

, s . I.Y Manuanctsers MSDS rw r fNega I Cassac TL TJ. _: , 2 , _ .. c; B q9ne) cunere use = 0 1 CD NO w 4 =,

{W,3f'y%

N e' - surash 0 87-13 (96 hr) deanse (40%)

Cat Ftx L "J : , J , - c; 9 (9mo) cupere une = 0 1 CD ND , f JjN Mormdaraners MSDS Caqan Bauaga i dewee (40%)

1 .E{'t O--D'T suresh 0 82-13 (96 hr)

W TW Co W B W) 15 2 I CD W , T,Q - hs MSDS Natm ChemcA l Ft w 8(see) are C cunere see = 0 i CD NO 85348PW4 F,agetW-5: % v:rv No data avsenete I Hygersperse Petracytc Aoo(35%) 8 (smolW C 363 t CD NO 1RIGEll84EI4t' 350 DAW **D; t' F - <- Manutschners MSDS Argo Chemuc ;

sAsweemod :gaes Ace (37%) B (8 men arw! C 202 S NT NA N W'T e No data avaantee 67 5V D NA Netsy tyvp easeyt <=. .n- , No d.g. ,, e,e.e t ysd* C angrety stx*d - g- e f otenryta ^ew^,Ji?O%)

Q',h.gif

?

% I,. g.,?.P g om seerd(10%) .

C 85 9 S.V D NA

's r- No dau avadabee [

L estd

W cronrama m o '

puproery) h;

%;4 A Saodoord sonet ' 5 ' -

pre Of ~

~

r soeum Hyeomde Tas ed Faey Aca! sodum sat ;

Ca. Soeum Sarmee (40%) 8 (1mel 257 5 NT NA N N JMt:IC. No data avadabee i 5 No appercupw gestesmnse pe e. ws usediorare<9henge m arrr m =>.m) Srewec De=rvere e t9 year) 25 Aayec en 6 N TWA.W!Nt7 No batey data avadabee B Icur oney ret 0 $ CD MA { - y;. used m sie waty, weat ent tacen* u Soeum tmwame soewn tiedme (sond) used) 4 .;,; W codeomate ichiome e useo to cwan diik reverse Osnote Manes-to date b= l

.$4 -W. has na ticen done .

i

\

t i

?

1 Page 2 of 2 l l

i

^

TABLE 2 COMMERCIAL CHEMICALS PROPOSED FOR USE IN PLANT SYSTEMS Temposam,,e_pmo k M y AnnualLeestig E #

Commsecleichemical Descherge p heprest ,

trado Nome Comunericat Chemicol temposition Frequency appresemose i ,i W '

Tronoport Fate Perelessace I, 1 ISMay

, y Re8erence te44 C....,_._,

C arW B(9no) 14TE43 S CD M

{J100 item y Csed Cu s0(24 Iw) MSDS Ago Chew.as 5 Ap 5?__ @ J C and 8(9no) 336E43 s CD M

...--t DEC) Dets bom EPRI TR.102952 *PWR Advanced

, Anune We C_. -- .* 1

- 2emno. 2 metys propenol C and B(9nol 290E43 S CD M

, Noostse adstne

'N 3 Hydronymenuckke C and B(kno! 406E43 S CD M h No ests o.aestse rrm* dine Wasse Beend Pyndens

C and B (9no) 2 32E*03 S CD M * -

3 2 8 ppm NOEC Ior Law Red

eanne Deteo u.* ']h , , '/ Canyon Nudoor PterW Repe1(1d96)

&a:paisse C ae p ande B(9no) 2 00E 41 M S CD -

[#I 42 porn NOEC lor tsw Red Ateene Detno <

l Canyon Nudsar Plant Report (12!96)

. I MA C.; ,06.,^_ _ , B(t/mol 2.0043 ' ~ ~ " S"~ CD M , ' N'o svedstWe W 300 trespotessunt: W ,a ,:.c. ,1 C 956E43 S CD M 1 conosphonese(35%) .g, No eats eveestne

?7 W;.

- 1xms W,'_

(50%)

Etencs(10%)

f ammanunctdondo B(2 yr) 2 09E.04 S CD M M A n . t's h;

Cagen ChenucalMSDS.me e scocacany a we I

i

.aC N N f,.;.;,^.1,L _ , sat of B(2ty) 209 04 eroveme22 iiw S CD M i 05h .

Campon Chemcas f ocnacas asu srwet n.< ., ;-

2.3 cartosyto sod

)y ~ ,f,

i

i p

g --

11 i i i ith 11: 11 l !! ! ! ! iii; !! !u i !! il l !! i lh ! l l i l i l i l l l l i l i l l i IkEl l ! ! ! ! ! ! 1 111111111183 l l.ilH il i i l i l l ! I l l l l il l l i lli i li Il, a I

I 1 li i i ! ! I i r

! . . . . . . . . 8 a a . . . . . . . . . . . . .

I! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! i l I I 5 5 4 4 4 6 9 9 I 9 5 6 6 6 4 6 6 6 . 5 6 . .

t I '

i l.l 1 .

1 1

. . 4 j

I I hhk[ [ 5 l!! l l I h l IIIIII l l l I I !

11 l l'- l' I l l l i m i i i i i i i hli n 4

M yh ENCLOSURE 2 TO NYE-98021 6

L I

4 t

e d

l I

Proposed Change to the Discharge Limit for Methoxypropylamine _ . ,.

Introduction Methoxypropylamine (MPA) and ethanolamine (ETA) are products that are used for corrosion inhibition in the secondary systems (Main Steam and Condensate Systems) at Seabrook Station.

During the time period of 1990 to 1997 the power plant industry and the pressurized water nuclear unit operators in particular have been intensely focused on their secondary chemistry control programs as a means of improving plant reliability and efficiency. Pressurized water reactor operators have designed their secondary chemistry programs to employ the amines, MPA and ETA. !

North Atlantic Energy Service Corporation (North Atlantic) requested EPA approval on January 13, 1995', to initiate the use of methoxypropylamine (MPA) as a secondary chemistry control agent at Seabrook Station. The EPA and New Hampshire Department of Environmental Servi:es subsequently approved the discharge of MPA on April 13, 1995,* and April 21, 1995,5 respectively, at a maximum discharge concentration of 0.5 ppm. The EPA and NHDES l approvals were founded on toxicity daut which demonstrated that the discharge concentration j would not be expected to significantly impact the aquatic community or public health. The i 4

approvals were also in recognition of the expected reduction in the utilization of Hydrazine.

North Atlantic estimates that the current secondary chemistry regime has a reduced Hydrazine concentration of approximately 50 percent as a result of the use of MPA.

North Atlantic, in conjunction with its application for renewal of NPDES Permit NH0020338, is propMing an increase in the maximum discharge concentration for MPA from the current limit of 0.5 ppm to 2.5 ppm. The proposed limit, like the current limit, is applicable at the Circulating Water System discharge point, Outfall 001. The proposed limit is supported by aquatic toxicity data for marine species as discussed below which demonstrates that the aquatic community will not be significantly impacted.

The proposed increase in the MPA limit is associated with a planned design change that will install a Condensate Polishing System (C"S). The CPS will be placed in service to expedite secondary system cleanup as necessary after a refueling or maintenance outage. Additionally, if a small condenser tube leak occurs during plant operation causing seawater leakage into the plant's secondary system, the CPS will be placed in service to remove the seawater contaminants while the leak is located and isolated. He CPS is designed to maintain secondary chemistry within acceptable limits for plant operation during small condenser tube leak events. Large

' NAESO Lener dated January 13. 5. " Request to Use Methoxypropylamine at Seabrook Station" Mr. R. Jeb DeLoach to Mr. Edward K. McSwe-

EPA Lener dated April 13,1995, i vosed Use of Methoxypropylarnine" Mr. Edward K. McSweeney to Mr. R.

Jeb DeLoach

' NHDES Lener dated April 21,1995," North Atlantie E.nergy Service Corporation (NAESCO) NPDES / State Surface Water Discharge Permit No. Nil 0020338" Mr. Rayrnond P. Caner to Mr. R. Jeb DeLoach Page 1 of 7

i L

condenser tube leak events would exceed the ability of the CPS to maintain acceptable secondary chemistry and would result in plant shutdown. It is estimated that the CPS will be operated two 1 to three weeks per year on average. During normal plant operation, the CES will be irtstandby i and actual discharge concentrations of MPA will be equivalent to the current discharge l concentrations which are well below 0.5 ppm.

The proposed increase in the MPA discharge concentration limit will significantly increase L .

operational flexibility and may avert a plant shutdown during condenser tube leak events. At the cunent MPA discharge limit of 0.5 ppm, the rate of discharge from the CPS would be very limiting with the potential that the discharge tanks could not be emptied fast enough to accommodate the required number of demineralizer resin regenerations for the condenser tube leak conditions. At the proposed MPA discharge limit of 2.5 ppm the CPS tanks could be discharged five times faster allowing more time for demineralizer resin regeneration and possibly ;

avening plant shutdown during a condenser tube leak event.

l The avoidance of a plant shutdown is imponant from an environmental perspective. The volume of water discharged as a result of a plant shutdown is an additional 50,000 to 70,000 gallons containing chemicals currently being used as additives for chernistry control. Additionally, the ,

operation of Seabrook Station for a single day equates toithe displacement of approximately 1 46,500 barrels of oil and many thousands of pounds of combustion gasses. i MPA Toxicity i i

l ne Material Safety Data Sheet for Pre-Tect 2040HP (40 % MPA by weight) provides the following aquatic toxicity data: i 1

I l 96 hour0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months LC50 (fathead minnow): > 1000 ppm 96 hour0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months LC50 (bluegill sunfish): > 1000 ppm ;

48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months LC50 (Daphnia magna): 694 ppm Shon Term Chronic for Ceriodaphnia dubia:

No Observable Effects Concentration for survival (Ceriodaphnia dubia): 50 ppm No Observable Effects Concentration for reproduction (Ceriodaphnia dubia): 6.25 ppm j ne Northeast Utilities Environmental' Laboratory (NUEL) performed marine aquatic toxicity l testing in April 1997 on the chemical product Conquor 3585 (40 % MPA by weight). The l pending NPDES Permit renewal application for Millstone Station propos s to use Conquor 3585 )

at Millstone Station Unit 1. The fo!!owing marine aquatic toxicity results were reported by NUEL to the Connecticut Depanment of Environmental Protection in October 1997.

48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months LC50 (Mysidopsis bahia): 259.13 ppm No Observed Acute Effects Level (Mysidopsis bahia): 86.38 ppm (Probit Method) l l

Page 2 of 7

q f

48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months LC50 (Mysidopsis bahia):

226.37 ppm]

No Observed Acute Effects Level (Mysidopsis bahia): 75.46 ppm (Spearman Karber Method) ._ -

96 hour0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months LC50 (Cyprinodon variegatus): 1000 ppm No Observed Acute Effects Level (Cyprinodon variegatus): 333.3 ppm (Spearman Karber Method) i 96 hour0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months LC50 (Cyprinodon variegatus): ; 1060.66 ppm 1

No Observed Acute Effects Level (Cyprinodon variegatus): 353.5 ppm (Binomial Method)

/

MPA is soluble and easily dispersed in the seawater environment. The product will decompose in the seawater environment and does not exhibit a propensity to bioaccumulate.

The proposed MPA discharge limit of 2.5 ppm is a factor of 30 below the NOAEL for !

Mysidopsis bahia, the most sensitive of the tested marine species. The proposed MPA discharge limit is applicable at the Circulating Water System discharge point, Outfall 001. The MPA i concentration will be further reduced by the discharge nozzle design which provides rapid ;

mixing with the surrounding seawater in thejet mixing region. It is estimated that the mixing in this region will result in a dilution factor ten. The MPA concentration at the proposed discharge i limit would therefore be approximately 0.25 ppm after this further dilution or a factor of 300 below the NOAEL for Mysidopsis bahia.

4 Given the wide margin between the proposed MPA dischbge limit and the NOAEL for the most sensi,tive of the marine species that have been tested North, the discharge of MPA at a maximum l discharge concentration of 2.5 ppm will not impact the aquatic community. ;

t North Atlantic will conduct a toxicity test at a time when the CPS Neutralization Tank is being discharged after the regeneration of the demineralizer resins. The NPDES Permit Renewal application proposes two toxicity tests during the term of the permit. This toxicity test will be conducted using the testing protocol identified in the NPDES Permit and will constitute one of the tests required by the permit. The NPDES Permit has been annotated to reflect this proposed change (see attached). 4 d

CPS Descrintion The Condensate Polishing System (CPS), when implemented, will be an integral part of the :

Condensate System. The CPS is designed to remove dissolved and suspended impurities from the Condensate System such as sodium, chloside and iron which can cause corrosio'n and fouling of secondary components. The system will normally be in a standby condition and is expected to j j be placed into operation under the following plant conditions: '

Page 3 of 7

}

4 Saltwater Intrusion into the Condensers Seabrook Station has experienced only two minor seawatcIleaks into the condensers sirtcc-1989.

For minor seawater leaks such as'those that have occurred at Seabrook Station, the CPS is t capable of maintaining acceptable secondary chemistry to allow the plant to remain at full power operation while the leak is located and isolated. In the event of a seawater leak the CPS may be operated for approximately 1 2 weeks while the leak is located and isolated. ;

i i Refueling Outages and Other Plant Outages t !

-It is expected that the CPS would be operated for approximately 2 - 3 weeks at the end of a !

refueling outage during plant heatup, startup and power ascension. Refueling outages are currently scheduled about every 18 months. The CPS may also be operated during other scheduled or unscheduled plant outages. For brief plant outages the CPS may not be operated,

- while for longer duration outages it may be operated for approximately 2 - 3 weeks as in a refueling outage, a i ;

o An overview drawing of the Condensate Polishing System.is attached. The CPS design consists of cation resin vessels, mixed bed resin vessels, pumps and associated equipment, and a resin regeneration and waste processing s'ystem. De CPS is designed to accommodate approximately l one third of the total condensate flow or approximately 7500 gallons per minute. The resin vessels remove the ionic constituents from the Condensate System including the amines (MPA l and Ethanolamine) used for secondary chemistry control. He resin regeneration.and waste l processing system is used to regenerate the resin for re use and to discharge the regeneration and !

rinsate wastes. Sodium Hydroxide and Sulfuric Acid are the expected regenerant chemicals.

The discharges from' the CPS System include: rinses of the CPS components prior to operation and periodically during standby conditions, rinses of the rnin vessels following regenerations, l regeneration wastewater, sampling system and grab samp!c waste, system leakage, and system i drainage for maintenance. I The CPS regenerant waste will be collected in the Neutralization Tank (30,000 gallon) and Low l Conductivity Tank (32,000 gallon) and sampled prior to discharge to ensure compliance with NPDES Permit effluent limitations and monitoring requirements prior to discharge to Outfall 001.

Quantifiestion ofImnact of 0.5 com and 2.5 onm Discharme Limits on CPS Operational Flexibility 1

l During operation of the CPS, the secondary system contaminants and secondary chemicals l including the corrosion inhibiting amines. MPA and ETA are removed by the demineralizer resins. The demineralizer resins must be regenerated every two to three days, during operation of the system, in order for them to be effective for contaminant removal. Regeneration may be required more frequently than this under larger condenser tube leak events. Regeneration of the demineralizer resins results in the generation and discharge of regenerant waste and rinsate waste Page 4 of 7 1 4

1 from th: CPS tanks. Based on the cunent and projected concentrations of the chemicals used in l the secondary system, MPA will control the rate of discharge from the CPS tanks because it is used in the highest concentration. The current NPDES Permit limits for ETA (0.5 ppm),

liydrazine (0.5 ppm), and Ammonia (0.5 ppm) at Outfall 001 can be complied with at CPS discharge rates corresponding to a MPA discharge limit of 2.5 ppm. -

l The CPS design incorporates sufficient cation bed and mixed bed deminerali7ers to accommodate continuous uninterrupted operation of the system while a cation bed or mixed bed ,

demineralizer is being regenerated. Three cation bed and four mixed bed demineralizers are l included in the CPS design while only two cation bed and three mixed bed demineralizers are required for full operation of the system. The CPS can be operated at reduced capacity with less than two cation beds or three mixed bed demineralizers in service. The cation bed or mixed bed

demineralizer that is not in service will be regenerated while the CPS is in operation and the freshly regenerated bed will then be placed into service while another bed is regenerated.

The paragraphs below specify the required regeneration and discharge activities during a typical week that the CPS is in operation and the amount of time required to perform those activities. At the curant MPA discharge limit of 0.5 ppm, the rate of discharge (23 gpm) from the CPS would be very limiting, requiring 66 hours7.638889e-4 days 0.0183 hours 1.09127e-4 weeks 2.5113e-5 months , with the potential that the Neutralization Tank may not be emptied fast enough to accommodate the required number of demineralizer resin regenerations.

Assuming that three regenerations are required in a typical week, approximately 121.5 to 136 hours0.00157 days 0.0378 hours 2.248677e-4 weeks 5.1748e-5 months of the 168 hour0.00194 days 0.0467 hours 2.777778e-4 weeks 6.3924e-5 months week are required to perform the regeneration activities. If larger

condenser tube leakage events were experienced there , would be insufficient tirne to accommodate four or more resin regenerations. In the event that four or more tesin regenerations l were required but not achievable under the current MPA discharge limit of 0.5 ppm, the CPS i

would be forced to operate at reduced capacity which may:not be suflicient to avoid a plant shutdown due to unacceptable secondary chemistry parameters. At the proposed MPA discharge limit of 2.5 ppm the discharge of the Neutralization Tank can be accomplished in 13 hours1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months , which is 53 hours6.134259e-4 days 0.0147 hours 8.763227e-5 weeks 2.01665e-5 months faster than is achievable than under the current MPA discharge limit of 0.5 ppm. This 53 hours6.134259e-4 days 0.0147 hours 8.763227e-5 weeks 2.01665e-5 months would provide significant operational flexibility of the CPS such as accommodating a founh resin regeneration in a week or allowing for any unanticipated system

, malfunctions that may impact regeneration or discharge times.

l Reseneration and Discharge Activities and Times at MPA.Dischame Concentration I imit of 0.5 nom It is uticipated that two cation beds would require regeneration each week, requinng 1

approximately 8 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months per regeneration. Assuming conservative removal ratch by the resms, the calculated concentration of MPA in the Neutraliation Tank is 3939 ppm, following a canon

bed regeneration. A mixed bed regeneration is anticipated to be required once per week, also requiring 8 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months for regeneration and resulting in the same concentration (3939 ppm) in the Neutralization Tank. The dinharge from ti;c Neutralitation Tank is mixed with at Icast 190 000 gpm of seawater in t e h Circulating Water System discharge structure anunung only one Circulating Water putnp and two Sersice Water pumps are in operation. When the plant is opt sting at full power the Circulating Water Systern flow is approximately t50,000 gpm with Page 5 of 7 1

l all three Circulating Water pumps and two Service Water pumps operating. In order to maintain a 0.5 ppm MPA discharge limit in the Circulating Water System discharge structure the Neutralintion Tank discharge rate can be no more than 23 spm. Following.cach cation or mixed bed regeneration there is an additional resin rinse using the Low Conductivity Tank that generates approximately 21,000 gallons of low conductivity water to be discharged from this tank. Since the Low Conductivity Tank is discharged through the same Dowpath as the Neutraliation Tank, the discharges cannot proceed simultaneously.

The times required for each of these activities are summarized as follows:

Activity llours per week i

Cation Ded Regenerations (2/ week) 16 - 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Mixed Bed Regeneration (1/ week) 8 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Neutrallation Tank recirculation prior to discharge 18 - 21 hours2.430556e-4 days 0.00583 hours 3.472222e-5 weeks 7.9905e-6 months ,

(2 volumes @ 150 gpm,3/ week) I Neutrallation Tank Sample analysis (post Recirculation) 7.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months l

Nei:tralization Tank Discharge (3/ week) 66 hours7.638889e-4 days 0.0183 hours 1.09127e-4 weeks 2.5113e-5 months Low Conductivity Water Tank Discharge (3/ week) 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months j Total Weekly llours for Regeneration 121.5 136.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months I and Ikegeneration Waste Discharge '

Reneneration and Discharue Activities and Times at MPA Direharue Concentration Limit of 2.5 com At the proposed MPA discharge concentration of 2.5 ppm, the required resin regen: ration and discharge activities are the same as above. Since the Neutrallation Tank can be discharged five times faster at this MPA limit, the time required for discharge of the Neutrallation Tank is reduced from 66 hours7.638889e-4 days 0.0183 hours 1.09127e-4 weeks 2.5113e-5 months to 13 hours1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months . This 53 hour6.134259e-4 days 0.0147 hours 8.763227e-5 weeks 2.01665e-5 months decrease in Neutrallation Tank discharge time provides signincant operational Hexibility as discussed above.

Activity llours per week Cation Bed Regenerations (2/ week) 16 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months i

Mixed Hed Regeneration (1/ week) 8 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Neutrallation Tank recirculation prior to discharge 18 21 hours2.430556e-4 days 0.00583 hours 3.472222e-5 weeks 7.9905e-6 months (2 volumes @ 150 gpm,3/ week)

I Page buf 7 1 l I

i Neutralization Tank Sample analysis (post Recirculation) 7.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months

~

Neutralization Tank Discharge (3/ week) 13 hour1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months Low Conductivity Water Tar.k Discharge (3/ week) 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months i Total Weekly Hours for Regeneration 68.5 - 83.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months ;

and Regeneration Waste Discharge

Conclusion:

i North Atlantic, in conjunction with its application for renewal of NPDES Permit NH0020338, is l proposing an increase in the maximum discharge concentration for MPA from the current limit of 0.5 ppm to 2.5 ppm. De proposed increase in the MPA limit is associated with the planned design change that will implement a Condensate Polishing System (CPS). This new system is extremely important in ensuring the long tenn reliability and efficiency of Seabrook Station.

The expected operational time for the CPS is very limited, estimated at two to three weeks per year on average. During normal plant operation, the CPS will be in standby and actual discharge concentrations of MPA will be equivalent to the current discharge concentrations which are well i below 0.5 ppm. He proposed increase in the MPA discharge concentration limit will afford ,

significant CPS operational flexibility allowing system operation at full capacity and potentisily :

avoiding an otherwise unnecessary shutdown of Seabrook Station. Here is a wide margin between the proposed MPA discharge limit and the No Observed Acute Effects Level of the most sensitive of the marine aquatic species that have been tested, thus there will be no impact on the aquatic community. Toxicity testing will be performed during discharge of the CPS Neutralization Tank to verify that the aggregate wastewater does not effect the test species. ,

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Page 7 of 7 1

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Page 9 of 26 j Permit No. NH0020338 '

.: en.

The following chemicals are approved for water discharge. These discharge levels-may not be increased nor chemicals substituted without written approval by the Regional Administrator and the Director or their designees. The permittee must demenstrate that the aquatic toxicity of the proposed changes are equal to or less than approved chemicals herein listed.

Calculated Maximum Discharoe #001 Plant Product Concentration, com Water System Hydrazine 0.5 Secondary Steam System Ammonia 0.5 Secondary Steam System Boron 5 Primary System

, Lithium Hydroxide 0.5 Primary System l Hydrogen Peroxide 0.5 Primary System Ethylene Glycol 50 Exterior Heating / Cooling System Propylene Glycol 50 Satae as Ethylene Glycol Bulab 9328 0.4 Corrosion protection for fresh water systems Bulab 6002 20 Biocide in cooling tower Cat Floc TL 0.1 Liquid Radwaste System.

To facilitate the removal

]p materials made radio- l active by neutron '

radiation in primary q system S Cat Floc L 0.1 Same as Cat Floc TL Nalcolyte 7134 0.1 Satae as Cat Floc TL Sodium Nitrite 0.5 Heating / Cooling Systems' Sodium Molybdate 0.5 Heating / Cooling Systems Sodium Silicate 5 Auxiliary Secondary System Scale Inhibitor Morpholine 0.1 Steam Generators Ethanolamine 0.5 M,p Secondary Steam System Flocon 0.01 Sequestering Agent Mgt,{ Q Q S,,h3 M Q J S Q @Se N fSty mj @ M 9EMhs studie ar=it.evaar.WM=st involving;.newAchemicaYalno WWWIEi esa#gcurrently~.E F]

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Page 13 of 26 Permit No. NH0020338 l.

The permittee shall perform chronic toxicity tests following the protocol in Attachment A (dated July 1991) on 24-h6ur composite effluent Jul" 10 0 i2 EMF"Ef 2dl""f511E!1E^#'IEc'?ffEEffi""Et?"E!

fHih' F9IQ*~Th~$~spe'cIIs~fBF't3IE YErY'fs'f.%E*IIi1a~'d'~"

n 511Ye"$si'de 'lMenidia bervilina) . Chronic and acu*.e toxicity '

data shall be reported as required in Attachment A. Results of these toxicity tests are to be submitted mc felleer:

.Ganw;ri scrpling rc; ult; du; b, Jun; 15th and th; July s;;41ing r;; ult; duc by 0;pt:ric 15th. This permit shall be modified, or alternatively, revoked and reissued to incorporate additional toxicity testing requirement and to include limits if the results of these toxicity tests indicate this discharge causes an exceedance of any water quality criteria.

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ENC 1.OSURE 3 TO NYE-9802I o

M i

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i I

Proposed Change to Analytical Method r Cooling Tower Chlorine Analysis s

Introduction Discharges from the Seabrook Station Cooling Tower (Outfall 027) are subject to the effluent limitations and monitoring requirements specified in the NPDES Permit. Free Available :

Chlorine, pH and flow are the parameters required to be monitored for Outfall 027 at a frequency of"once daily" during a discharge. North Atlantic is proposing to revise the NPDES Permit to change the current requirement for Free Available Chlorine analyris to Total Residual Chlorine analysis. The current NPDES Permit requirements for Outfall 027 have been annotated (see attached) to reflect this proposed change in chlorine analysis.

The Cooling Tower (part of the Service Water System) is pesigned to Provide a safety related, :

seismically qualified source of cooling water to safety-related plant systems. During normal operating conditions, extended use of the Cooling Tower is infrequent. Normally, the cooling ,

water for plant systems is supplied by the ocean Service Water pumps, however on occasion the !

Cooling Tower is placed in service providing the cooling water supply. The Seabrook Station Operating License requires the Cooling Tower be placed in service on a quarterly basis to verify that the cooling water supply can be aligned to the siety-related source of cooling water provided by the Cooling Tower. This evolution occurs approximately every six weeks because !

each of the two Cooling Tower water trains must be tested each quarter. The Cooling Tower may Ao be operated to allow maintenance to be performed on the ocean cooling water pumps or ;

durii', winter months to warm the fresh water supply in the tower basin. The Cooling Tower l provides a safety-related source of cooling water in that it is designed to fcnction after a seismic !

event where it is postulated that the ocean cooling water supply is unavailable due to collapse, and blockage of the cooling water tunnels. During accident conditions involving the unavailability of the ocean cooling water supply, the Cooling Tower would supply cooling water to plant systems that are required for safe shutdown. The entire Cooling Tower is constructed ,

over a storage basin that contains 3,900,000 gallons of fresh water (primarily). This volume of l water is sufficient to dissipate the design heat loads for seven days without the addition of makeup to the basin.

Normal makeup water is supplied from the Potable Water System which is supplied by the Town of Seabrook well system. Water may also be supplied from other sources if potable water is not available or a more rapid makeup is desired. Some other sources include: seawater from the forebays, fire protection main water, water from the Brown's river, seawater from Hampton Harbor, or any other onsite water that may be available for use in an emergency.

Although the Cooling Tower can operate on seawater, it is prudent to maintain the salinity and total dissolved solids of the basin water as low as possible during normal operation. The normal total dissolved solids level of the Cooling Tower water is 3000 - 5000 ppm (ccmpared to 4

seawater at 35,000 ppm). When the Cooling Tower pumps are aligned to operate, their discharge Page 1 of 3 i

l

flow path is aligned to the' Service Water System which is filled with seawater. During the transition of 'a Cooling Tower isolation valves from full closed to full open, the seawater and potable water .a the piping is discharging both to the ocean and to the Cooling Towcc basin.

When the Cooling Tower pt.mps are to be taken out of service, the piping now filled mostly with Cooling Tower water, is discharged to the ocean and to the Cooling Tower basin. During these [

evolutions small amounts of seawater are introduced into the Cooling Tower ' ain.

Cooling Tower blowdown is a discharge of a volume of t e Cooling Tower water inventory to Outfall 001, specifically intended on reducing water level in the basin. This blowdown is typically performed to reduce tower salinity and/or total dissolved solids following extended operation. The reduction in these parameters occurs due to the makeup of fresh water to the system. Discharge of Cooling Tower water may also be performed to prevent overflow of the baain if the Cooling Tower water level reaches a high level such as the result of a series of rainfall events.

Cooling Tower water is treated to minimize biofouling and scaling of the sys'em components.

Sodium hypochlorite is normally added to the Cooling Tower during summer months to inhibit :

biol>gical growth. A silica based anti-scalant is also added to minimize scaling in the Cooling l Tower. He nr ti scalant is addec' oa an as-needed basis as determined by basin water sampling.

Elatu111ea l

De Cooling Tower basin is filled with potable water and e; such, the methodology which was proposed for the analysis of sodium hyochlorite was the Free Available Chlaine Method (FAC).

Seawater however, may also be present in u;e basin as discussed above. The presence of seawater in the Cooling Tower basin is confirmed in the weekly a alysis of the Total Dissolved Solid's (TDS). The TDS concentration in the basin is typically about 3500 ppm which is about 11.5 times greater than potable water (~300 ppm). North Atlantic estimates tha. the basin water is comprised of a mixture of about 10% seawater (~35,000 ppm TDS) and 90% potable water

(~300 ppm TDS). The bromide ion concentration of the cooling tower water will therefore be about 10% that of seawater, or ~6 ppm. The bromide ion is converted to hypobromite and will titrate in exac'tly the same manner as hypochlorite therefore Total Residual Chlorine, and not FAC is the appropriate analysis to perform.

The concentration of chlorine in the C5oling Tower water is controlled to 2- 5 ppm during the summer months and has a naturally buffered pH of >7.5. The conversion of hypochlorite in that water proceeds as follows:

OCl* + Br' -------------> OB r* + C1' 1

Thus the active oxidant in the cooling tower is hypobromite,just as it is in the Circulating Water i System when chlorination is in progress.

North Atlantic Chemistry personnel discovered that the desired pil range for the Free Available

Chlorine analysis for Outfal1027 was not being achieved by the addition of only one milliliter (ml)

Page 2 of 3 r . . - - - ,- , . m -,

of pil buffer solution. Chemistry personnel have determined the necessary volume of pil buffer to ensure proper pil adjustment and have made the necessary procedure changes (see Discharge Monitoring Report for June 1998). North Atlantic is confiaent that this_ modified procedure accurately reflects the oxidant level in the cooling tower water. 1 Proposed Chance to Analytical Method North Atlantic proposes that the NPDES Permit be revised to authorize the use of EPA Method 330.1, " Chlorine, Total Residual", for analysis of the Cooling Tower chlorine concentration as this method is more appropriate for analysis of chlorine in seawater. The NPDES Permit currently autMrizes this method for the analysis of TRC in the Circulating Water System (Outfall 001). EPA Method 330.1 is also authorized in 40 CFR 136 " Guidelines Establis' g Test Procedures for the Analysis of Pollutants". North Atlantic believes this to be a n:

appropriate method due to the deviations from Standard Methods 4500-Cl 7 required analysis of FAC and since that method is not intended for seawater solutions. uthenn . ac use of Method 330.1 for the Cooling Tower will establish consistency in analytical n . umb between this discharge and the Circulating Water System discharge (Outfall 001).

I I

Page 3 of 3 1

.s

) .: v/

Page 20 of 26 Permit No. M10020338 Part I During the period begiming Effectivehte and lasting thrtugh Expiration Date, the permittee is 9.]

authorized to discharge fr' cutfall(s) serial ntrrt:er(s) 027, .Mlic f cboling 'Ibwer Blewdown 2' ILi*LSJblH-

a. Such discharges shall be limited and wonitored by the permittee as specified below:

Effluent O nracteristic Discharue Limitations Itnitorim Reauirements Measurement Saerple Ave. Pixithly Max. mily Preauency 'INm Flow, gpd Repr. . Report Daily

Estinnte h A,oilsble I D / Me3 /J=n/

Odorine K, ng/l 0.2 0.5 Daily

Grab

Sanple frequency is once daily when Ateeniary (boling *Ibwer has a .

i

b. %e pit shall not be less than 6.0 standartl units nor greater than 9.0 standard units and shall be sanpled daily by a grab sanple when in use.

c. None of the 126 priority pollutants shall be used for cooling tower maintenance chemicals. "

d. %e sanples taken in cenpliance with the nonitoring requirements specified above shall be taken at a

-r msentative point prior to mixing with any other strearn.

e. Mt hs:Ju-fCfhe,e. b y EPA nLJ 330 ? '

I

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N t,n CD

I l

l ENCLOSURE 4 TO NYE-98021 s

6e e

!. l Molluscicide " EVAC

as an Alternative Iliocide i l

Chlorination (using sodium hypochlorite) is currently the only biocide approved far,use at Seabrook Station. No other biocide may be used without prior approval from the Environmental l Protection Agency (EPA) and the New Hampshire Depanment of Environmental Services (NHDES) per Pan I.A.I.a of the Seabrook Station NPDES Permit. Chlorination at Seabrook ,

Station involves the continuous application of low-level concentrations of sodium hypochlorite in the Circulating Water System, throughout the year, except during early January to early March when ocean water temperatures are cold and biofouling activity is very low. The Service Water System is chlorinated throughout the year due to its safety related function.

Nonh Atlantic has previously requested' EPA approval to conduct an alteraate biocide feasibility study at Seabrook Station using the molluscicide EVAC *. jThe proposed feasibility study, is i designed to assess the ability of the molluscicide to control the growth of mussels and bamacies (macrofoulers) at Seabrook Station as well as to determine the most effective concentration of EVAC

to be applied. Provided that the feasibility study proves successful, Nonh Atlantic will evaluate the use of EVAC

on a full scale basis as an alternative biocide at Seabrook Station.

North Atlantic expects that a significant reduction in the amount of sodium hypochlorite can be realized through the full scale use of EVAC *.

Although the EPA approval for the feasibility study is still pending, North Atlantic has provided herein funher information and proposed NPDES Permit changes in support of full scale use of EVAC *.

i EVAC

is a dicarboxylic acid monoamine salt of endothall. In application the amine ponion comes out of solution and coats available surfaces, including the target organisms. He method of action against molluscs is that the product coats the gill surface and interferes with oxygen ,

transfer. According to Calgon Corporation (a distributer of biocide products) the active ponion of EVAC

has a high affinity for surfaces and in applications the amine has been shown to be ;

significantly reduced in concentration as it moves through plant piping. In addition, EVAC

I has a half life of about 24-hours in seawater.

He following discussion is North Atlantic's current best estimate of the parameters related to the full scale application of EVAC *: ,

l EVAC

is intended to be applied up to three times per year during the peak macrofoulmg j season for durations of 1 3 days per application during the beginning, middle and end of the peak fouling season. EVAC

application dosages and durations will be determined by the results of the feasibility . study and first full-scale application (e.g.1.5 ppm (0.3 ppm amine) for 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , 44 ppm (0.5 ppm amine) for 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months and 4.3 ppm (1.0 ppm amine) for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ). Chlorination ;

would be terminated during EVAC

applications and resumed at dosages lower than current l doses after the EVAC

application.

North Atlantic Letter NYE.98020, dated July 20,1998." Request for Approval to Use Molluscicide in Alternate Biocide Feasibility Study." J. Han (Nonh Atlantic) to C. DeLoi (EPA) and H. Stewan (NHDES).

Page 1 of 2

)

lt is not possible to predetermine the acttni discharge cacentrations of EVAC

without actual sampling. Given the fact that the active portion of EVAC

has a high affinity for surf;tecs and suspended solids and in actual power plant applications has been shown to be significantly reduced in concentration as it moves through plant piping, the actual discharge concentration following Dow through Seabrook Station's three mile long discharge tunnel is expected to be significantly less than the application dosages provided above, in addition, upon discharge from Seabrook Station's Circuidng Wr.ter System discharge diffusers nozzles, the effluent is funher diluted by a factor of ten witnin a shon duration from the diffuser nozzles in the jet mixing region, funher minimizing any potential impact to the environment caused by residual discharges of EVAC *. EVAC **s relatively shon half life of about 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months in seawater, funher reduces potential environmental impacts. Assuming two applications per year, the annual EVAC

usage would be approximately 20,900 pounds with the actual quantity discharged into the environment significantly below this quantity for the aforementioned reasons.

Nonh Atlantic's request to perform the EVAC

feasibility study included a letter prepared by Peter Howe, Life Scientist, Environmental Protection Agency (EPA) Region 5. Mr. Howe's letter wasofaccompanied manufacturer EVAC I bg)a white which discusses the corepaper toxicity developed data for EVAC *.by Calgon The studies Corpora containing these core data have been reviewed and accepted by EPA Region 5. The Calgon/ Elf Atochem white paper includes aquatic toxicity data for a number of freshwater fish and invenebrate species, specifying a Final Acute Value of 0.073 mg/l for the amine based on the available LC-50 data. A Calgon Corporation Fact Sheet " EVAC Acute Toxicity to Mysid Shrimp" estimates the 96-hour LC50 acute toxicity and No-Observed-Effect Concentration values for the sensidve marine species, Mysid Shrimp as 2.4 mg/l and 0.74 mg/l respectively.

The, EVAC

discharge concentrations are expected to be significantly less than the aforementioned toxicity levels.

Although continuous low level chlorination will need to be continued during the peak fouling season, except when EVAC

is actually beingapplied, the quantity is expect be significantly reduced from those levels used without EVAC applications. The actual sodium hypochlorite reduction can be quantified after the feasibility study is completed and a full scale EVAC

application is conducted. It is expected however that the reduction in annual sodium hypochlorite use may range from 20% to 50% or approximately 1.1 million to 2.78 million pounds. This reduction in the amourit used would equate to an annual sodium hypochlorite reduction in the discharge of approximately 6,000 to 16,000 pounds based on chlorine usage during the last year. Reductions in chlorine usage will be specified in the annual Chlorine Minimization Repon.

Page 2 of 2

22 Page 2 of 26 Permit No. NH0020338 Part I - - -

A. Effluent Limitations and Monitoring Requirements >

i 1.

Except as specified in Paragraphs 1 through 10 herein, the pemittee shall not discharge to the Atlantic Ocean or to the Browns River, a final effluent to which it has added any pollutants.

7 h . Chlorine may be used as a biocide No other biocide shall be used without explicit

" l approval i

9 from the Regional Administrator and the Director, r~ Par.I.A.1.f

~~sse'djb~e16s ~Ktit~eiel'5Aij g m//uscic '28, ,

terna e1ilii.61 Kid gpe , e.sy also ya~

be. used .

_n , - - - g--

u ec.fr,on N

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$s'

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f . ,.g ,

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b$ Total Residual Oxidant (Chlorine) concentration, unless otherwise specified, shall be measured i

a downstream of the unit o units being chlorinated

'f before that stream mixes with the receiving water.

The total oxidant or chlorine residual of the effluent shall not result in any demonstrable harm 4

to aquatic 2ife or violate any water quality standard which has been promulgated.

~

2-

c. The discharges shall not jeopardize any Class B '

use of the receiving waters and shall not violate applicable water quality standards for Class B water as-defined by the State of New Hampshire,

d. The permittee shall not at any time, either alone or in conjunction with any person or persons, cause directly or indirectly, the discharge of any waste into the receiving waters except waste that l has been treated in such a manner as will not lower the Class B quality or interfere with the t

uses assigned to said waters by the New Hampshire Legislature (Chapter 311, Laws of 1967).

1

e. This permit shall be modified, revoked or reissued 3 to comply with any applicable effluent standard or limitation issued or approved under Sections

301 (b) (2) (C) and (D), 304 (b) (2), and 307(a) (2)

I i

i i _. - --

ML20151P600

Text

Conclusion:

= -

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