ML19329A253

Responds to Technical Assistance Request 1435 Re Impingement Loss Significance at Facility & Adequacy of Tech Specs.Nrc Evaluation Incomplete Due to Insufficient Info.Recommends Tech Spec Amend Proposal & Fish Population Study

ML19329A253
Person / Time
Site:	Oconee
Issue date:	05/27/1975
From:	Harold Denton Office of Nuclear Reactor Regulation
To:	Muller D Office of Nuclear Reactor Regulation
References
NUDOCS 8001020828
Download: ML19329A253 (7)

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&/d9A I' s Wf71975 I

Daniel R. Huller, Assistant Director for Environmental Projects, EL RESPONSE TO TAR NO. 1435 i

PLANT NAME: Oconce Units 1, 2 and 3 LICCISING STAGE: OL DOCTIT hTMBERS: 50-269, 50-270 and 50-287 PISPONSIBLE BRANCH: Environmental Projects Branch No. 2 PROJECT !!AMAGER: Mark Au DATE REQUEST RECElVED BY ESB: February 20, 1975

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DESCRIPTION OF RESPONSE:

j Comments on Significance of Impingement Losses at Oconec and Adequacy of Current Impingement I

Technical Specification EEVILN STATUS:

Environountal Specialists Branch Review Complete

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This is in response to your request (TAR No.1435) to evaluate the i

significance of fish impingement at Oconeo and the adequacy of the i

existing it:pingetent technical specification.

l Dr. John J. Dolen of the ESB staff not with Duke Power representatives at the Oconec site to review the fish impingement problem and observe screen monitoring techniques.

He later talked with Department of l

Interior's Fish and Uildlife Service (Southeast Reservoir Investigations) and South Carolina State Wildlife and !!arine Resources Department i

personnel regarding fish impingement at Oconec and threadfin shad l

population levels in Lake Keovee.

I Our review indicates that at the present time there is inadequate data availabic to deternine the significance of impingcuent losses on the Lake Keovce fishery.

of past screen counts and insufficient information on the threadfin population $n Lahe Keovec.

described in the enclosure. The basis of our conclusion is more fully To provide an adequate estimate of fish mortality at the station and to deteruine the significance of irginnenent losses on the reservoir i

fishery it is reconnended that the following actions be impleuented by I

the licensee at an early date:

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MAY 2 i 1975 l

Daniel R. Ifu11cr (1) Submission of a proposed revised _ fish impingemont l

monitoring specification which includes provisions for continuing the current monitoring of the six selected fixed screens at an increased frequency i,

of at least two to three times per week. In

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addition, a special study should be conducted to correlate total screen kills wit 9 those on the six screens being routinely monitored. Number, weight and length of impinged fish should be determined for each species with respect to year class.

Delete the current specification requirements for weekly visual inspections of the intake structure, j

quarterly underwater visual inspections of the screens, and n report when more than 100 fish are collected. A revised requirement reflecting the j

fish impin:;ement level that shall initiate a i

formal report should be proposed.

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(2) A study should be initiated immediately to estir. ate the threadfin shad population in Lake Keowee. *rne population should be estimated during each season l

and be based on data developed by midwater trawl and townet techniques. This program should be i

designed to complement other ongoing surveys being i

conducted by the Fish and Wildlife Service's i

Southeast Reservoir In3estigations.

Our review was conducted by Dr. John J. Bolen of the Environmontal i

Specialists Branch.

W Siped by i

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Harold R. De:iton, Assistant Director for Site Safety Division of Technical Review l

Office of Nuclear Reactor Regulation l

Enclosures As stated cc: See next page i

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4' STAFF EVALUATION f

Our_ evaluation of the significance of fish impingement at Oconee and the adequacy of the ' existing impingement technical specification is i

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based on (1) a site visit to the Oconee station on February 27,1974

.to confer with Duke Power biologists and observe.the imoingement.

monitoring procedure, (2) telephone conversations with the U. S. Fish and Wildlife Service and South Carolina State Wildlife.and Marine Resources Department personnel regarding the present and future plans for the Lake Keowee fishery and their opinions on the fish losses i

currently being experienced at Oconee, and (3) review of data i

describing impingement losses at the station for the period July 11, 1974 through April 10, 1975.

~ Duke Power biologists indicated that they did not believe the current impingement levels of threadfin shad were adversely affecting

~ Lake Keowee populations.

However, they could not provide any documen-tation to support their contention. The State of South Carolina in a letter I

to Duke Power dated February 25, 1975 expressed the opinion that if fish

.i mortalities continued at the February level (about 95,000/2 weeks) there

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would definitely be an adverse impact on the Lake Keowee fishery Further contact with the State of South Carolina indicated resource.

that no data were available to support this opinion either. The State also indicated that present plans were to maintain a largemouth bass fishery in Lake Keowee but no additional stocking of sport fish would

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be considered until the effects of Oconee operation were evaluated.

The Fish and Wildlife Service's Southeast Reservoir Investigations representative indicated that population estimates for threadfin shad, either absolute or relative, would be necessary for a definitive evaluation of Oconee impingement effects. He.c octed j

that field gear needed to sample threadfin shad for population estimates was already in use at Lake Keowee and with one to two additional staff members the necessary sampling could be conducted.

The licensee has been cote, ring, weighing and sizing fish collected on

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six of the twenty-four fixed screens every two wecks since May 16, 1974

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in conjunction with FWPCA 316(a) and 316(b) exemption procedures.

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our judgement, the reliability of these data is questionable because i

sufficient information is not available on (1) fish losses from the screens due to decomposition during the two week period between (2) loss of impinged fish from the screens during pump measurements, outage between the two week measurements, and (3) the number and variability of impinged fish on the unexamined screens.

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July 11, 1974 and April 10, 1975, the licensee reported about 250,000 fish impinged on the fixed screens routinely examined.

Based on the licensee's data, a conservative value for the number of fish that could have been impinged during this period assuming normal plant operation (3 pump operation per unit on a year-round basis) has beet. estimated. The i

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i estimate assumes that (1) impingement is proportional to volume flow, (2) the average numbar of fish on the two screens routinely measured at-each unit are representative of (Se impinged fish occurring on the 1

unit's remaining six unmonitored screens, and (3) the unidentifiable decomposed fish on the screens are of the same species composition as those that are identifiable. Our estimate for this period is about 2.5 million fish with 92%, 6% and 1.5% being threadfin shad, yellow perch and bluegill, respectively. Although the assumptions may be overly simplistic the estimate does provide a shad impingement number that is of the same order of magnitude that has been observed and predicted at other reservoir-sited plants similar to Oconee.

j Reliable estimates for the threadfin shad" population in Lake Keowee are i

not available. A single cove rotenoning effort approximately six months after the initial stocking of the lake with threadfin shad, in August, 1974, yielded 457 threadfin shad per acre from an approximately 10

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Extrapolation of this value to Lake Keowee total acreage,1ves

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acre area.

a population estimate of about 8.5 million threadfin shad; however, cove s

rotenoning is known to provide unreliable shad population estimates.

j Based on the foregoing analysis we conclude that unless the licensee can demonstrate to the staff's satisfaction that the existing impingement monitoring program is providing reliable estimates of screen mortalities and number, weight and size of impinged fish with respect to year class, the program modifications recommended in our transmittal should be I

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4 on We also conclude that our position transmitted to you implemented.

h d impingement April 30,1975 (response to TAR Nos.1563 and 1419 on s a f design or at Arkansas One) which stated

"...in the absence o the licensee is t

operating modifications to minimize impingemen,

damage is being sustained l

obligated to demonstrate that no appreciab e by the reservoir fishery." is applicable to Oconee.

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