ML20141F626

Repts Activities Which Include Discharge of Wastewaters from RBCCW Sys Via Dns 001B-2 & Seawater from RBCCW Sys Drains Via Dsn 001B-9

ML20141F626
Person / Time
Site:	Millstone
Issue date:	05/06/1997
From:	Scace S NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES SERVICE CO.
To:	Grier J CONNECTICUT, STATE OF
References
SES-97-GN-075, SES-97-GN-75, NUDOCS 9705210389
Download: ML20141F626 (3)

Text

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Q Hartford. CT 06141-0270

. (203) 665-5000 May 6,1997 -

SES-97-GN-075 D11074 , , ,'

.l Mr. James Grier Supervising Sanitary Engineer Water Management Bureau Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Reference 1' Letter D10751 from S. Scace to J. Grier dated February 11,1997 Reference 2 Letter D10837 from S. Scace to M. DiNoia dated February 24,1997 ,

Reference 3 Letter D10873 from S. Scace to J. Grier dated March 6,1997 Reference 4 Letter D10935 from S. Scace to J. Grier dated March 26,1997 Reference 5 Letter D10962 from S.'Scace to J. Grier dated April 11,1997

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ReDort of Millstone Unit 2 Discharaes

Dear Mr. Grier:

Northeast Nuclear Energy Company (NNECO) has previously discussed with you the protocols for the discharge of certain wastewaters due to maintenance activities associated with the heat exchangers at Unit 2 (References 1,2,3,4 and 5). In this l letter NNECO wishes to report activities which include the discharge of wastewaters l from the Reactor Building Closed Cooling Water (RBCCW) system via DSN 001B-2 )

(Aerated Waste Radiation Monitor Tank ) and seawater from RBCCW system drains via DSN 001B-9.

! 4 Aerated and Coolant Waste Monitorina Tank Discharaes l NNECO has previously (4/14/97,4/21/97 and 4/24/97) Verbally discussed with you the discharge via DSN 001B-2 and 0018-3 of Reactor Building Closed Cooling Water IS

- (RBCCW) wastewaters due to maintenance activities associated with draining of the Unit 2 "A" RBCCW header . These activities occurred on April 12,19 and 24,1997.

This wastewater included system drains from the radioactive portion of the RBCCW g/f h

system and contained hydrazine.' Hydrazine is not addressed in NNECO's NPDES

' permit at DSN 0018-2 or DSN 0018-3. These waste waters were processed through /

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' demineralizers and filters associated with DSN0018-2 and DSN0018-3 and, at the time of each discharge, the wastewaters were below detectable limits for hydrazine

(< 3.2 ppb). The following provides additional details with respect to each discharge.

Hydrazine Concentration Discharae Date Volume Discharaed at Discharae DSN0018-3 4/12/97 19,656 gallons Below detectable DSN0018-2 4/19/97 1,576 gallons Below detectable DSN001B-2 4/24/97 2,452 gallons .! Below detectable RBCCW Service Water Drains During the month of April, activities associated with the draining of seawater (i.e.,

service water) included:

- Draining of seawater (i.e., service water) from the "A" Reactor Building Closed Cooling Water (RBCCW) service water header and high pressure washing of the "A" RBCCW heat exchanger using either demineralized or domestic water from April 1,1997 to April 9,1997.

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- Draining of seawater (i.e., service water) from the "B" Reactor Building Closed Cooling Water (RBCCW) service water header from April 12,1997 to April 25, 1997.

1 Due to these maintenance activities, the normal pathway (DSN 001B-5) could not be I used and these wastewaters were directed to the RBCCW sump and discharged from l DSN 001B-9. Consistent with our past approach for these types of activities, the titration method was used for the analysis of hydrazine. At the time of discharge, hydrazine was below detectable limits (< 350 ppb). l The following provides information with respect to each discharge of service water from the RBCCW occurring during the month of April 1997:

DRAIN OF "A' RBCCW SERVICE WATER HEADER Volume Free Available Date Discharaed (aal) Chlorine (ppm) Activity Temp. (F) 4/01/97 3440 Service water <0.02 Drain & 72 hydrolazing 4/02/97 1116 Service water <0.02 Drain 70 4/03/97 7652 Service water 0.02 Drain & 74 hydrolazing 4/04/97 540 Service water <0.02 Drain 72 4/05/97- 324 Service water <0.02 Drain 71 4/07/97 352 Service water <0.02 Drain 70 4/08/97 784 Service water <0.02 Drain 71 ,

4/09/97 644 Service water <0.02 Drain 69

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DRAIN OF "B" RBCCW SERVICE WATER HEADER Volume Free Available Date Discharaed (aal) Chlorine (6pm) Activity Temp. (F) 4/12/97 2680 Service water <0.02 Drain 66  ;

4/14/97 1200 Service water <0.02 Drain 67 4/15/97 368 Service water <0.02 Drain 67 4/16/97 144 Service water <0.02 Drain 70 4/24/97 1836 Service water 0.10 Drain 50 4/25/97 1008 Service water 0.03 Drain 68 During each of the above RBCCW sump discharges, a minimum of at least two condenser circulating pumps were in operation and the maximum daily flow did not  ;

exceed 30,000 gallons per day.

Should you have any questions, please call Mr. Paul Jacobson, Environmental Services- Nuclear, at (860) 447-1791 Ext. 2335.  ;

l Very truly yours.

NORTHEAST NUCLEAR ENERGY COMPANY i

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