ML20198F516

Forwards Monthly Discharge Monitoring Rept for June 1997 for Millstone Nuclear Power Station

ML20198F516
Person / Time
Site:	Millstone
Issue date:	07/31/1997
From:	Scace S NORTHEAST NUCLEAR ENERGY CO.
To:	CONNECTICUT, STATE OF
Shared Package
ML20198F520	List: ML20198F516 ML20198F561
References
SES-97-GN-127, NUDOCS 9708130068
Download: ML20198F516 (5)

Text

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Northeast Raed=784Nda Utilities System wwwutsr ,y c P.o. aos 12s we erocas-otas (860) 447 1791 July 31,1997 SES 97 GN 127 D11266 DMR Processing Department of Environmental Protection Water Management Bureau

-79 Elm Street Hatford, CT 06106-5127

Reference:

Letter (C04876), NPDES Permit No. CT0003263, Millstone Nuclear Power Station, l Northeast Nuclear Energy Company, dated December 14,1992.

Millstone Nuclear Power Station Monthly Discharge Monitoring June 1997 Paragraph 3 of the referenced NPDES Permit requires that discharges from the permitted facility ..

be monitored according to a specified schedule and results be reported to the Water Management -

Bureau by the end of the month after the month in which samples are taken. Northeast Nuclear 1 Energy Company (NNECO) herein submits the attached report for the month of June 1997. Any i variations from the permit are explained in the section headed "Results and Discussions" enclosed, l Additional samples taken at NPDES locations and analyzed with approved methods are included cn Tables 3, and 4.

Should you have any questions or require further information, please call Mr. Paul Jacobson, Environmental Services Nuclear at (860) 447-1791 ext. 2335. 1 f

V;ry truly yours, f NORTHEAST NUCLEAR ENERGY COMPANY S. G. Scace cuu f

s[ f Director.- Nuclear Engineering Programs Enclosures g Q' (

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cc: Mr.' James Grier <-

NRC NRC Residentinspector 9708130068 970731 ,

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Introduction

[ NPDES Monthly Report-June 1997 i- / l

! This report fulfills the monitoring requirements for Millstone Nuclear Power Station, NPDES - I

Permit No. CT0003263, renewed December 14,1992.

As requested by the Department in a letter to each NPDES facility, dated January 1,1988

- (C01988), and recognizing the Department's requirement to submit data to EPA, NNECO will l

make every effort possible to submit the DMRs as early in the month as possible, in cases where the required data are not available, the DMRs will be submitted no later than the last day

of the month in which they are due.

L i Results andDiscussions Results of the continuous, weekly and monthly monitoring programs are summarized on the ,

f DMR sheets attached. With the exception of hydrazine, ethanolamine and boron, all sampling

and analyses were conducted in accordance with approved methods set forth in EPA i Publication 600/4 79-02. NNECO submitted its.own analysis methods for these chemical substances (D10309) for Department approval on October 4,1996.

[

The computerized data logging report of the continuous monitoring program (int'ake and i discharge) for the month is included as Table 1. This report is included because it provides

! data for the daily range of pH, temperature and flow, a requirement of the NPDES permit. The -

r DMR form does not have provisions for daily ranges. These data are computer generated  :

' summaries of 15 minute sample averages.

I I

General Note - DMR Forms 7

p The DMR forms have some~ errors,- omissions, and incorrect reporting requirements when l~ - compared to the permit requirements. They are included and defined on Table 2.

[; As discussed with the Department on July 14,1997 NNECO has made, with the Department's concurence, some minor changes to the DMR forms. Where appropriate, units were changed

! from upper case to lower case and Roman letters were changed to Greek (i.e. u changed to p and DEG F changed to 'F). Additionally, the discharge serial number and data entry sections l of the forms are now highlighted. None of the coding or identifiers used by the Department

have been modified in any way, i- Notification of Service Water System Strainer Backwash Discharge l-l By way of verbal notification on May 20 and 22,1997, and by way of letters dated May 27, 1997, (D11148) and June 20,1997 (D11192), NNECO advised the Department of the discharge of service water system strainer backwash water at Millstone Units 1,2 and 3. As

! explained at a meeting with the Department on May 29,1997, backwash water is supplied by

_ the service water system. NNECO has confirmed that the strainer backwash water at all three 1  : Units contains residual chlorine. The waste water generated from the backwash operation at

Units 1 and 2 flows to the screenwash discharge (DSN's 002 and 003 respectively). The

. - discharge of the Unit 3 strainer backwash flows to two pipes (each approximately 3 inches in

j. diameter) located on the east and west faces of the Millstone 3 intake structure,

j. 2 l:

%'. 1. . .

As part of NNECO's response to this matter, all three units have developed procedures which )

manually halt the injection of chlorine into the service water prior to backwash of the service water strainers, thereby allowing the backwash water to be free of chlorine. Normal chlorination of the service water is then resumed following strainer backwash. However, under this

= arrangement,~ in certain circumstances, it wiIl not be possible to prevent the use of chlorinated..

service water during strainer backwash such as when the strainers backwash automatically as a result of hlgh differential pressure caused by heavy amounts of debris in the service water.

NNECO is continuing its review of enginering altomatives to address this concem.

Exceedsnee of the Total Suspended Solids Liniit at DSN 009 On June 26,1997, the monthly storm drain sample for DSN 009 was collected. The sample was taken during a thunder storm under conditions of very high flow and was proceeded by a significant dry period. At this discharge, the limit for Total Suspended Solids (TSS) is 30 PPM.

The TSS result of the surface water runoff sample taken was 31.2 ppm. It is believed that the conditions under which the sample was taken caused the excedence. ,

High pH st DSN 006 On June 3 at 3:55 PM, a weekly grab sample at DSN 006 indicated a pH result of 9.5, A second sample was taken at 4:30 PM which indicated a pH of 9.58 at DSN 006. Millstone personnel then initiated an investigation to determine the source of the high pH As part of NNECO's investigation, discharge pumps for the Unit 2 East Condenser Pit sump were secured at 6:00 FM. Once the Unit 2 East Condenser Pit i my was isolated, additional pH sampling at DSN 006 indicated a pH of 8.95 (below the limit r 7s < :., O PM. Further investigation by site .

personnel determined that waste waters containt a 6: ry a grout had inadvertently entered the Unit 2 East Condenser Pit sump, it is believt a a w . rete grout raised the pH in the East Condenser Pit sump, and, consequently in the di arm; 7SN 006.

Once isolated, the East Condenser Pit sump and oil o s. : operator were then cleaned with domestic water that had been processed through a carbon filter to remove chlonne.

Approximately 2,990 gallons of the resulting waste water were then removed by a licensed outside contractor for disposal off site.- Following removal of the waste water, pH at the East

- Condenser Pit sump was measured at 8.03.

This event was reported verbally to the Department on June 4,1997 and in writing (D11193) on June 9,1997.

Hydrazine Removal Prior to Discharge via DSN 001C-2

. On the dates listed below, wastewaters containing small amounts of hydrazine were detected in the High Level Waste Drains Tanks (HLWDT) associated with DSN 001C-2. Consistent with previous discussions with the Department, the wastewaters in the HLWDTs were processed through tne domineralizers and filters associated with DSN 001C-2 prior to discharge from the Waste Test Tanks. These wastewaters met alllimits associated with DSN 001C-2. Further, no hydrazine above detectable limits (<5 ppb) using spectrophotometry was found. The initial concentrations detected, dates and volumes discharged are provided below. These discharges 3

y ., 1;. .

. were reported in writing to the Department on June 20,1997 (D11220) and July 23,1997

- (D11307),-

lnitial Concentration foob) Date 0% charmed Volume Discharoed (gallons) 50 June 7,1997 18,060 71 June 14,1997 .18,060 687 June 28,1997 18,690 Unit 3 Closed Coollag Water Systems In correspondence dated April 14,1997, (D11003), June 20,1997,(D11192), and in Discharge Monitoring Report (DMR) submissions for the months of March (D10872), April (D11112) and May (011188), NNECO described to the Department the presence of dichlorodifluoromethane (freon) in the Reactor Plant Closed Cooling Water system and the Reactor Plant Chilled Water system. NNECO has previously advised the Department that Millstone personnel have been instructed to collect all Reactor Plant Closed Cooling Water draina9e and Reactor Plant Chilled Water drainage in containers for ofFsite disposal. Since NNECO verbally notified the Department of this matter on April 9,1997, all drainage from these systems has been collected in containers and properly disposed of off site, in addition to the above, NNECO has also been monitoring discharges from DSN 001C-2 and 001C 3 for the potential presence of freon in the radioactive treatment systems. As set forth in the table below, freon has not been found above the limit of detection in any of the subsequent

( - sampling. However, in performing this analytical testing, as also shown below, trace levels of other organic substances were occessionally detected in certain discharges. These trace levels of other organic substances are believed to be byproducts of solvent usage in the plant, it is also possible that sample contamination during laboratory testing may also be a cause for some

• of these values NNECO, based on its review of all sampling results, and after discussions with the Department on July 9,1997, has discontinued its voluntary sampling of the parameters listed below.

Volatile Organic Compound Analysis Results at DSNs 001C-2 & 001C-3 Compound Concentration (ppb)

Date DSN chloro acetone . 1,2 . xylenes dichloro toluene carbon methane dichloro difluoro disulfide ethane methane 6/6/97 001C-3 u u u 8.0 u u* u-6/6/97: 001C-2 u u u u u u u 6/13/97- 001C-3 u u u u u u u 6/14/97- 001C-3 u u u 6.8 u u- u

- 6/14/97 - 001C 2: u u -

u u u u- u 6/20/97 - 001C-3 u u u u u u u 6/21/97 001C-3 u u u u* u . u* u 6/27/97 001C-3 u u u u u u u 6/27/97 001C-2 u u u u u u u Notes:

u = undetected u'= below limit of quantification of 5 ppb 4

n. '

Determination of differential temperature & heat loading for Units 2 & 3 The intake temperature measurements taken at the Unit 1 intake have been used this month in determining the differential temperature across each unit and in calculating heat loading.

Measurement could not take place at Unit 2 due to intake temperature instrumentation maintenance and measurement at Unit 3 could not take place because the circulating water pumps were not in operation and there was insufficient flow within the intake piping to allow the temperature probe to obtain readings. Ordinarily, in such a circumstance at Unit 3, NNECO's data monitoring system (EDAN) would use intake temperature data taken at the Unit 2 intake.

Since maintenance work is being performed on the Unit 2 probe, intake data taken from the Unit 1 probe is being utilized for Units 2 & 3. The Tab;e i printout for these parameters reflects the use of the instrumentation at Unit 1.

! Unit 3 Auxiliary Boller Sampling in correspondence dated June 20,1997 (D11192), NNECO advised the Department that sampling at DSN 001C-6(b) (Auxilliary Boller) would continue to be performed at the Auxilliary Boiler during periods of operation and would also be performed weekly (regardless of where the Auxilliary Boller is operating) at the Auxilliary Boiler blow down sump which is down stream of ancillary sources of Auxilliary Boiler wastewater. The data provided in Tabte 4 reflects the sampling practice described above. As the Auxilliary Boiler was not in operation this month, sampling took place weekly at the blowdown sump.

Free available chlorine loading for DSN's 001 A,001B & 001C in addition to its current method of calculating chlorine loadings, NNECO is also providing an attemative method as part of this DMR. The current method assumes continuous chlorination and maximum monthly flow; the alternative is based upon an actual chlorinttion time of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> ./

per day and actual flow during chlorination and sampling. NNECO is currently evaluating both methods.

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