ML20136H018

1996 Environmental Operating Rept for Oyster Creek Nuclear Generating Station

ML20136H018
Person / Time
Site:	Oyster Creek
Issue date:	12/31/1996
From:	Roche M GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
9530-972-1498, NUDOCS 9703190030
Download: ML20136H018 (5)

Text

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GPU Nuclear, Inc.

U.S. Route #9 South G, NUCLEAR Post Office Box 388 Forked River, NJ 08731-388

- Tel 609-971-4000 6530-972-1498 l February 28, 1997 U. S. Nuclear Regulatory Commission Attention: Document Control Desk

. Washington, D.C. 20555

Subject:

Oyster Creek Nuclear Genemting Station (OCNGS)

Docket No. 50-219 Annual Environmental Operating Report i

Enclosed are two (2) copies of the 1996 Annual Environmental Operating Report (AEOR) for the .

OCNGS. The AEOR is submitted in accordance with Section 3.5.l(A) of the Oyster Creek l Environmental Technical Specifications (OCETS). I If you have any questions concerning this submittal, please contact Mr. Malcolm Browne of our Environmental Affairs staff at (609) 971-4124.

Sincerely, i

hl h Michael B. Roche Vice President and Director Oyster Creek Nuclear Generating Station MBR/MEB:jdr Enclosure i cc: 5. Collins (NRC)

NRC Resident Inspector, OC R. Eaton (NRC)

J. Lapoti (NJDEP) 9703190030 961231 PDR ADOCK 05000219 R PDR 180109

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t 1996 ANNUAL ENVIRONMENTAL OPERATING REPORT )

OYSTER CREEK NUCLEAR GENERATING STATION LICENSE NO. DPR-16 DOCKET NO. 50-219 i

PREPARED BY:

GPU NUCLNAR, INC.

MARCH,1997

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. 'I 0 INTRODUCTION '

This ' document is the Oyster Creek Nuclear Generating -Station (OCNGS)- Annual -

l Environmental Operating Report (AEOR) for 1996. This report is required by Oyster -

l Creek Environmental Technical Specification (OCETS) Section 3.5. l(A).'

l The OCNGS is a single cycle, forced circulation, boiling water reactor of 620 MWe l maximum (summer) dependable net capacity, owned by Jersey Central Power & Light

! l Company and operated by GPU Nuclear, Inc. The OCNGS is located in Lacey Township, -

Ocean County, New Jersey. The plant is subject to Operating License No. DPR-16. The date ofinitial reactor criticality was May 3,:1969 and the commercial generation of power

! began on December 23,1969.

This AEOR covers the period from January 1,1996 through December 31,1996. The ,

report is organized in the following format:'

Section 1.0 - Introduction Section 2.0 - Environmental Monitoring Section 3.0 - Special Monitoring and Study Activities Section 4.0 - Additional Information i

2.0 Environmental Monitoring P'ursuant to Section' l.15f the OCETS, the Fish Kill Monitoring Program was initiated on May 6,1996 following a scheduled shutdown of the OCNGS dilution pumps.

The fish sampling program conducted on May 6 and 7,'1996 indicated that 1600 fish representing four different species died due to heat-shock shortly after the dilution pump shutdown. , Plant operators discovered shortly after the shutdown that a ' vacuum induced siphoning or backflow'of water through the dilution pumps resulted in increased water-temperatures in the plant's intake and discharge canals. A faulty dilution pump vacuum breaker valve was determined to have caused the problem and was subsequently repaired. <

It is believed that the increase in water temperatures following dilution pump shutdown, combined with the probable exclusion of some fish from areas of preferred water temperatures, resulted in the observed heat-shock fish kill. A copy of the Fish Kill Monitoring Program Report submitted to +he NRC on May 30, 1996 is provided as Attachment I.

= 3.0 Special Monitoring and Study Activities This section is intended to present the results of any special monitoring and study activities required by Section 2.0 of the OCETS.

Section 2.0 of the OCETS did not require the performance of any special monitoring or study activities during this report period.

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I, . ' 4,0 - Additional Information l

This section reports any additional information that is required by Section 3.5.1 of the OCETS which includes a summary of:

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a). All OCETS Non-Routine Environmental Operating Reports (NEOR) and the l corrective action taken to remedy them. 'l 2 .

b) Changes made to State and Federal Permits and certificates which pertain to the requirements of the OCETS.

c) Changes in station design which could involve an environmental impact.

1 d) ,

Changes to the OCETS.

4.1 - Summary of OCETS NEOR j

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i. A NEOR was filed with the NRC on May 30,1996 concerning a fish kill event described i in Section 2.0 of this report. As indicated previously, a copy of the Fish Kill Monitoring i Program Report is provided as Attachment I.

} 4.2 Summary of Changes Made to Federal and State Permits and Certificates which Pertain to i the Reguirements ofOCETS 1 l

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There were no changes to Federal and State permits and/or certificates pertaining to the i F OCETS during the reporting period.

4.3 Summary of Changes in Station Design Which Could Involve an Environmental Impact.

l There were no changes in, or modifications of, station design during the reporting period I which could involve an environmental impact.

4.4 Summary of Changes to the OCETS There were no changes to the OCETS during the reporting period.

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. ATTACHMENT I FISH KILL MONITORING PROGRAM REPORT l l

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1. . ATTACHMENT 1 GPU Nuclear Corporation i

UCISSr Post Office Box 388 Route 9 South Forked Rwer.New Jersey 08731-0388 609 971-4000 l

Writer's Direct Dial Number:

6530-962-1110 May 30, 1996 j Dr. Jason Jang ,

U.S. Nuclear hegulatory Commission l Region I l 475 Allendale Road i King of Prussia, PA 19406 l

Dear Dr. Jang:

l l

Subject:

Oyster Creek Nuclear Generating Station (OCNGS) i l

Docket 50-219 Fish Kill Monitoring Report, May 1996  !

In accordance with the reporting requirements of Sections 1.1.1 A and 3.5.2 of Appendix B, Environmental Technical Specifications, enclosed is a report of Fish Kill Monitoring at OCNGS.

If you have any questions or require any additional information, please contact Mr. Malcolm Browne of our Environmental Affairs Department at (609) 971-4124.

l Very truly yours, e 3d b Michael B. Roche A

Vice President & Director Oyster Creek MBR/MEB/jdr Enclosure cc: Director Bureau of Nuclear Engineering Office of Inspection and Enforcement NJ Dept. of Environ. Protection U.S. Nuclear Regulatory Commission CN 411 475 Allendale Road Trenton, NJ 08625 King of Prussia, PA 19406 Director NJ Dept. of Environ. Protection Nuclear Reactor Regulation Division of Fish & Game U.S. Nuclear Regulatory Commission Nacote Creek Research Station Washington, DC 20555 P.O. Box 418 Port Republic, NJ 08241 Document Control Desk NJ Dept. of Environ. Protection U.S. Muclear Regulatory Commission Central Bureau of Regional Enforcement Washington, DC 20555 Div. of Water Res., Enforcement Element State Highway 33 NRC Resident Inspector Hightstown, NJ 08520 OC Nuclear Generating Station GPU Nuclear Corporation is a subs: diary of Genera! Pubhc Utstees Corporabon

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FISH KILL MONITORING REPORT FOR MAY 1996 1

GPU Nuclear Corporation Oyster Creek Nuclear Generating Station Environmental Affairs Department May 1996

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Executive Summary The dilution pumps of the Oyster Creek Nuclear Generating Station (OCNGS) were taken out of service for maintenance, in j accordance with the conditions of the Station's NJPDES Discharge to

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Surface Water Permit, at 3 :32 a.m. Monday, May 6,1996, while OCNGS was operating at full power. Shortly thereafter, plant operators discovered that a vacuum-induced siphoning or backflow of water through the dilution pumps resulted in increasing water temperatures in the plant's intake and discharge canals. A faulty solenoid in the vacuum breaker valve designed to prevent such backflows appears to have been the cause of the problem.

As a result of the backflow, the water temperature in portions of.the intake canal near the cooling water intake increased from approximately 64* F to nearly 71* F during the initial three hours following dilution pump shutdown. The main condenser cooling water discharge temperature also increased by 2.5*F, to 86.5* F, during this period. The combined effects .of these events, and the probable exclusion of some fish from areas of preferred water temperature by schools of predatory fish prior to the dilution pump shutdown, resulted in a heat-shock fish kill. In order to document this event a fish sampling program was conducted by GPU Nuclear on May 6-and 7. The results of that monitoring effort indicated that 1600 fish representing four different species died, apparently due to heat shock.

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. . Atlantic menhaden (n=1500) accounted for 93.8% of the mortalities, weakfish (n=66) for 4.1%, vinter flounder (n=33) for 2.1%, and American eel (n=1) accounted for less than 0.1%.

In order to determine if any fish sank to the bottom subsequent to their death, bottom trawls were conducted at five locations between US Route 9 and the mouth of Oyster Creek. No additional dead fish were collected in any of these trawls. Live blueback herring and white perch as well as live invertebrates including blue crab, sand shrimp and grass shrimp, which appeared to have suffered no ill ef fects from the water temperature changes, were collected in trawls from Oyster Creek and adjacent residential lagoons.

In order to minimize the possibility of heat-shock mortality associated with future dilution pump outages, station personnel will verify that the vacuum breakers have operated subsaquent to shutting the pumps off. This will provide an opportunity to manually operate the vacuum breakers should they not function automatically.

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[ Introduction

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E This report documents the results of aquatic sampling f conducted by GPU Nuclear (GPUN) Corporation following a thermal

- shock fish kill which occurred on May 6, 1996 in the discharge l canal of Oyster Creek Nuclear Generating Station (OCNGS) subsequent to the planned shutdown of the dilution pumps for maintenance. The ,

objectives of the sampling program were:

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1) To determine the species composition, relative

' abundance and distribution of fishes in Oyster Creek which may have i

i suffered thermal stress following the dilution pump shutdown, and i.

l 2) To quantify the extent of any fish mortalities. ]

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-The monitoring effort took place on May 6th and 7th, 1996.

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OCNGS, which had operated continuously for the previous '4 i

days, was operating at full power with four circulating water and  !

I i two dilution pumps in operation on May 6. A planned shutdown of t

! the dilution pumps had been scheduled for the early morning on that day in order to perform routine maintenance on the pumps. The New i

Jersey Pollutant Discharge Liiminetion System (NJPDES) Discharge to Surf ace Water Permit for the OCNGS requires the operation of one or 1

j two dilution pumps when the intake water temperature is below 60'F '

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. l or,When the discharge canal temperature, as measured at the U.S.

Route 9 bridge, exceeds 87*F. The very short periods of time in 1

the spring and fall when neither of these conditions prevail, are i

the only times when all dilution pumps can be shut off for l l

preventive or corrective maintenance in accordance with the NJPDES permit conditions. Immediately prior to the shutdown of the I dilution pumps at 0332 hrs on May 6th, the intake temperature was approximately 64* F and the discharge temperature was approximately l

84 F (Figure 1). When the dilution pumps were shut off a vacuum l l

breaker, designed to prevent the backwards flow of heated ef fluent through the dilution pumps during pump outages, failed to operate properly due to a faulty solenoid. The resulting backflow of warm water from the discharge canal into the intake canal caused a I 1

relatively rapid increase in water temperoture in the intake canal (from 64*F to 71 F), and set up a pattern of recirculation which also increased the main condenser discharge temperature from 84 F to 86.5 F (Figure 1). When station personnel discovered the cause of the increasing intake water temperatures, they manually operated the vacuum breaker at approximately 0700 hrs, thereby stopping the backflow of warm water through the dilution pumps.

Dead and dying fish were first observed in the discharge canal by security personnel at approximately 1830 hrs on May 6. GPUN Environmental Af fairs personnel were notified at 1845 hrs and began collecting the dead fish at approximately 1915 hrs.

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.. -l 4 - Fish Kill Monitoring Activities -

Fish were collected by environmental scientists f rc m the discharge canal using dipnets. Dead fish were gathered from a small boat and by personnel walking along the_ discharge canal streambanks, between the OCNGS discharge and the mouth of Oyster Creek. All fish were identified and enumerated; length ranges were obtained.

A total of 1600 dead fish, representing four species, was collected (Table 1). Nearly 94% of the total were Atlant.ic menhaden. Weakfish, winter flounder and American eel comprised 4.1%, 2.1% and less than 0.1% of the total, respectively.

The majority of the dead fish (greater than 90%) were found in the dilution pump discharge area and behind the two spill containment booms located approximately 150m downstream. The l remainder of the fish were found along the banks of the discharge canal, primarily within about 300m of the U.S. Route 9 bridge. All of the dead fish were floating.

In order to determine if dead fish had accumulated on the bottom of the discharge canal and contiguous residential lagoons, bottom trawl samples were collected. Bottom trawls were conducted at each of three stations in the discharge canal and Barnegat Bay east of the Route 9 bridge, as well as within two of the

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residential lagoons, during the afternoon of May 7 (Figure 2).

Trawling was done with a 4.8 m semiballoon otter trawl with a 3.9 cm stretch mesh body, a 3.2 cm stretch mesh cod end and a 1.3 cm

stretch. mesh liner. All fish captured were identified and enumerated, length ranges were obtained, and the specimens were  ;

j released.

1 i All fish collected in the trawls were alive, exhibited no signs of thermal stress, and were immediately released. No fish were captured at Stations T3, T4, and T5 (Table 2). No fish were i

l captured at Station T1, but 30 blue crabs, 10 sand shrimp and 8 ,

grass ' shrimp were collected alive and released. No fish were captured at Station T6.(between 100 and 400 m east of Route 9) but one live blue crab was collected and released. Two live blueback l

herring (Alosa aestivalis) approximately 110 mm fork length (FL) l i

and two live white perch (Morone americana) approximately 100 mm FL were captured at Station T2 (the third residential lagoon east of Route 9).

Schools of fish, believed to be bluefish, striped bass and Atlantic menhaden, were observed swimming normally in the condenser discharge of the OCNGS during the evening of May 6th and on subsequent days. These fish were probably in the vicinity of the j condenser discharge flow at the time of the dilution pump shutdown and therefore not exposed to the thermal shock.

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i. . Fishermen at the U.S. Route 9 bridge reported catches of ]

l bluefish and striped bass during the evening of May 6 and the l

1 morning of May 7. I l

l Discussion and Conclusions The evidence indicates that the fish mortality was caused by i

3 heat shock and that behavioral factors other than the response to water temperature probably played a role in causing the fish kill.

The initial heat shock occurred when the dilution pumps were shut off and any fish in the dilution pump discharge area were exposed to water temperatures increasing from 64 F to 84 F. Smaller increases in water temperature were experienced in the mixing area between the condenser discharge and dilution discharge flows. The subsequent backflow of heated water through.the dilution pumps and into the condenser intake flow exacerbated the situation, causing the discharge canal water temperature to increase another 2.5 F to i

a maximum of 86.5 F.

If temperature preference were the only f actor controlling the movements of the Atlantic menhaden and weakfish in the discharge canal, these species should have avoided both the ambient temperature water (64*F) at the dilution pump discharge and the heated condenser discharge (84*F) prior to the cessation of dilution pumping. Temperature preference testing suggests that they should have preferred water temperatures of 77'F to 81'F which

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9 a . . would have been found in the mixing area between the dilution pump i

discharge and condenser discharge flows (Jersey Central Power &

Light, 1978). If that were the case, heat shock experiments have

shown (Tatham et al., 1978) that the increase in water temperature q

following the shutdown of the dilution pumps (approximately 6-10*F) i should not have caused heat shock mortality. The additional heat l shock of 2.5*F, caused by the backflow of heated water through the l

dilution pumps, would have been enough to cause mortality of i

weakfish which exhibit greater than 50% mortality when subjected to

temperature increases greater than 12 F (Jersey Central Power &

1 Light, 1978). Alternatively, the weakfish may have been excluded 1

from their zone of preferred temperature by larger or more abundant j predators, such as the bluefish and striped bass, forcing them to d

I reside in the cooler dilution pump discharge flow (64*F) . Shutting l off the dilution pumps in that case would have subjected the i

j weakfish to a 20*F increase in water temperature. That shock i

j alone, without the additional heat from the backflow through the

- dilution pumps, would have been sufficient to cause weakfish mortality.

Heat shock experiments have shown that Atlantic menhaden

exposed to an instantaneous 21.4 F increase in water temperature j-(from 57.2*F to 78.6*F) exhibited no mortality after 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

Only 20 percent mortality was observed _ following a 27 F increase in

water temperature from 57.2*F to 84.2*F. The LTw for this species j was determined to be 85.5 F at an acclimation temperature of 57.2*F g

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• - and 85.3*F at an acclimation temperature of 68*F (Tatham et al.,

) 1978). These results indicate that if the Atlantic menhaden were

occupying their preferred temperature zone prior to the dilution pump outage, the heat shock alone, including the 2.5*F increase in water temperature associated with the backflow through the dilution l pumps, should not have caused any mortality. The backflow through 1

the dilution pumps did cause the discharge canal temperature to rise above the LTso for this species however, and this may have been i

enough to induce the observed mortalities. Similarly, if the Atlantic menhaden were excluded from their preferred temperature )

zone by the bluefish and striped bass, and forced to reside in the 64 F dilution pump discharge flow, the results of heat shock experiments indicate that most or all of these fish should have survived the 20*F increase in temperature to 84 F after the ,

i dilution pumps were shut of f (Tatham et al. ,1978) . The additional 1

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[ increase in temperature associated with the backflow through the dilution pumps however, caused the discharge canal temperature to rise to 86.5'F, which is above the LTso for this species, and a heat shock sufficient to cause the observed mortalities.

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Temperature preference studies have shown that the winter i

flounder should have preferred the dilution pump discharge flow l (64"F) and avoided warmer waters (Jersey Central Power & Light, 1978). Winter flounder exhibited 100 percent survival after 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> in heat shock experiments in which they were subjected to a f 20 F increase in water temperature, from 59*F to 79 F. Complete i

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mortality was observed when this species was subjected to a 25 F increase in temperature from 59'F to 84'F (Tatham et al., 1978).

These results suggest that winter flounder residing in the dilution pump discharge flow may have survived the dilution pump outage l alone but the incremental shock associated with the backflow 5

through the dilution pumps was sufficient to induce the observed mortality.

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In order to minimize the possibility of heat-shock mortality j associated with future dilution pump outages, station personnel l

will verify that the vacuum breakers have functioned properly  !

l subsequent to shutting the pumps off. This will provide a timely opportunity to manually operate the vacuum breakers should they not i

function automatically and prevent heated condenser discharge water from being recirculated into the cooling water intake.

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References l l

l Jersey Central Power and Light Company. 1978. Oyster Creek and Forked River Nuclear Generating Stations 316(a) and (b) Demonstration. Jersey Central Power and Light Company, Morristown, New Jersey.

Tatham, Thomas R., Donald J. Danila, David L. Thomas and Associates.1978. Ecological Studies for the Oyster Creek Generating Station, Progress report for the period September 1976 -~ August 1977, volume one, fin- and shellfish. Ichthyological Associates, Inc., Ithaca, New York.

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Table 1. Number and size of dead fish dipnetted from OCNGS discharge canal and Oyster Creek following May 6,1996 fish kill.

SPECIES NUMBER PERCENT LENGTH RANGE MEAN LENGTH OF CATCH (mm) (mm)

Brevoortia tvrannus 1500 93.8 260-296 276 Atlantic menhaden Cynoscion ren_ajui a 66 4.1 272-494 372 weakfish Pseudooleuronectes americanus 33 2.1 271-382 329 2 whter flounder Anauilla rostrata 1 < 0.1 742 742 American eel TOTAL 1600 100

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