ML20247F711

NPDES Noncompliance Notification:On 890626,dead Catfish Discovered in Circulating Water Discharge Bay & Canal at Plant.During 890626-0710,167 Dead Fish Noted in Discharge Area.Fish Kill Suspected to Have Occurred Late on 890624

ML20247F711
Person / Time
Site:	Summer
Issue date:	07/20/1989
From:	Bradham O SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Krecker W SOUTH CAROLINA, STATE OF
References
NUDOCS 8907270225
Download: ML20247F711 (9)

Text

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b' -.f South Carolina Electric & Gas Company Ollie S. Bradham nuciear operanons

,gsc 290es geng.;sgie LSCE&G- 9 July 20, 1989 Mr. William R. Krecker Environmental Quality Manager Water Quality Assessments & Enforcement Division South Carolina Department of Health

& Environmental Control 2600 Bull Street Colombia, South Carolina 29201

Subject:

Virgil C. Summer Nuclear Station Docket No. 50-395 Final Report Fish Kills June 24-July 10, 1989

Dear Mr. Krecker:

. South Carolina Electric & Gas Company (SCE&G) herein submits the final" report concerning fish kills in the Virgil C. Summer Nuclear Station-(VCSNS) discharge canal between the dates of June 24 and July 10, 1989. The enclosed report describes the current events and probable cause.

In accordance'with the VCSNS Operating. License NPF-12, Appendix B, a copy of this report is being provided to the Nuclear Regulatory Commission.

Additionally, a copy of this report will also be provided to the South Carolina Department of Wildlife & Marine Resources per the request of Mr. H.

J. Logan, Chief >of Fisheries.

Should you require any further information, please contact Mr. Charles McKinney of my staff at your convenience.

Very truly yours,

/

U, 5 Bradham

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CJM/0SB: led Attachment c: et. B. Williams W. R. Baehr  !

S. E. Summer W. R. Higgins W. F. Bacon W. M. Lide, Jr.

Document 1Controlc(NRC)

R. L. Prevatte p.7/

NPCF RTS (ONO.890053) g

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Files (818.05 & 809.06-1) 8907270225 890720 '

1 PDR ADOCK 05000395 P PDC

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1 Fish Kill Report- June 1989 l On June 26,1989, dead catfish were discovered in the circulating water discharge bay and canal area at the V. C. Summer Nuclear Station (see Figure 1). Because of the j advanced state of decomposition of these fish,it was estimated that the fish were l probably killed late on 6/24/89. The South Carolina Department of Health and

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-l Environmental Control, the South Carolina Wildlife and Marine Resources Department and the Nuclear Regulatory Commission were notified of the fish kill. A preliminary report was submitted to the South Carolina Department of Health and Environmental Control on 6/30/89 (attached).

Observations were made of the discharge area on a daily basis from 6/26/89 to 7/10/89. During this time period,167 dead fish were noted in the dischar'ge area. Of these fish, one was a largemouth bass, two were white bass, and the remainder were catfish. Approximately ninety percent of the catfish were white catfish; approximately ten percent were channel catfish. Table 1 presents the numbers of fish and the dates observed. Since there were no unusual discharges from the V. C.

Summer Nuclear Station, it appears that the fish kill was due to thermal conditions present in the circulating water discharge area.

Fish kills have occurred in this area during this time of year in the past. In anticipation of a fish kill, a temperature monitor was installed on May 25,1989 in the discharge bay at a depth of approximately 30 feet. Data from previous fish kill investigations have suggested that fish were being tr6pped in a deeper area of the discharge bay as temperatures rapidly increased. The temperature monitor w,*s installed in this area (see Figure 1). Evaluation of the data from the temperat.ure monitor showed that the temperature variation on the bottom of the discharge bay was greater than the variation present in the water being discharged. In particular, daily fluctuations up to 11*F (average hourly temperatures) were noted. Of particular interest were the temperatures at the bottom of the discharge bay, which were considerably lower than the temperature of the water being discharged.

These discharge bay temperatures were compared to Monticello Reservoir ' water levels and a distinct correlation was noted. Since Monticello Reservoir is the upper reservoir for Fairfield Pumped Storage Facility, water levels may fluctuate several feet each day. It was found that lower lake levels were associated with higher temperatures on the bottom of the discharge bay and higher lake levels were

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1 associated with lower temperatures on the bottom of the discharge bay (see Figure 2' and 3).

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During hot weather, with V. C. Summer Nuclear Station operating at.100%, the l discharge canal becomes stratified. Hot water tends to occupy the upper portion of the canal and the bottom portion of the canal remains cool. Since the discharge bay is, at _its deepest, about ten feet deeper than the canal, cool water from the lake can

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apparently enter through the canal and, because of the density gradient, flow into -

the deeper areas. It appears that as the lak'e level drops, the hot water layer drops 1 also'and causes the water at the bottom of the discharge bay to heat up. If the temperatures are high enough, the fish that are present are killed. When the lake level rises, cool water can again flow into the discharge bay area from the canal, )

allowing fish to recolonize the area. This process appears to continue until the I

. temperatures in the discharge area remain so warm that the fish will not recolonize.

This suspected fish kill mechanism would help explain' why the fish kills in the discharge area tend to be limited to catfish, as these fish would be the most likely to be trapped near the bottom and would also be more likely to recolonize the area by following cool water inflows along the bottom of the discharge canal.

The frequency and extent of the fish kills caused by the suspected mechanism

~ discussed above appear to be dependent on the temperature of the circulating l

- water discharged from the V. C. Summer Nuclear Station, the water temperatures in Monticello Reservoir, and the magnitude of lake level fluctuation due to the operation of Fairfield Pumped Storage Facility. 4

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Stephen E. Summ6r, Supervisor Environmental Programs ]

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Table 1 Observed Dead Fish l June 1989 Fish KillInvestigation V. C. Summer Nuclear Station l Date of Number Observation of Fish identity 6/26/89 32 white catfish and channel catfish,5 - 8 inches total length 6/27/89 18 white catfish and channel catfish,5 - 8 inches total length,1 channel catfish 13 inches total length,1 channel catfish 16 inches totallength 6/28/89 74 1 white bass 13 inches total length,67 white catfish 5 - 10 inches total length,6 channel catfish 9 - 12 inches total length 6/29/89 13 white catfish 5 - 8 inches totallength 6/30/89 0 N/A 7/1/89 1 unknown

• 7/2/89 5 unknown

• 7/3/89 3 unknown

• 7/4/89 2 1 white bass 12 inches totallength,1 unknown 7/5/89 3 unknown

• 7/6/89 12 1 largemouth bass 15 inches totallength,11 ,

catfish 6 - 12 inches total length 7/7/89 0 N/A 7/8/89 0 N/A 7/9/89 0 N/A 7/10/89 4 unknown *

- l Total 167 1

• not inspected, seen from shore

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CIRCULATING WATER DISCHARGE Figure 1 June 1989 Fish Kill V. C. Summer Nuclear Station

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. Preliminary Report, June 1989 Fish Kill A fish kill was discovered in the Circulating Water Discharge bay (see Figure 1) at V. C. Summer Nuclear Station in the morning of June 26,1989. A total of twenty- l four fish were found and examined. The fish were all catfish,5 to 8 inches in total length. Most were white catfish, a few were identified as channel catfish. Most fish were badly decomposed and had apparently been dead for over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Tempera-ture data and the lack of any indication of unusual discharges infer that the fish kill was probably the result of increased temperatures at the bottom of the discharge l bay. It was suspected that the fish kill occurred late on 6/24/89. There were no fluctuations in power level at V. C. Summer Nuclear Station during the suspected time of the kill. After notification of regulatory agencies, eight more fish were noted the discharge bay (approximately 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br />).

The discharge area has been repeatedly inspected and there is indication that this is a series of fish kills, probably occurring late at night. On 6/27/89 eighteen dead fish were discovered (all catfish) and on 6/28/89 seventy-four dead fish were discovered. When it was realized that fish were continuing to be killed, regulatory agencies were notified. Since fish kills recurred after the initial notification, this is only a preliminary report. A complete report will be submitted after all pertinent data has been evaluated.

LAthm ~

Stephen E. Summer, Supervisor Environmental Programs 6/29/89 n

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MONTICELLO RESERVOIR p - Figure 1 June 1989 Fish Kill V. C. Summer Nuclear Station l

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