ML20079M948

DC Cook Nuclear Plant Units 1 & 2,Supplemental Rept Demonstrating Compliance W/Section 316(b) of Clean Water Act

ML20079M948
Person / Time
Site:	Cook
Issue date:	09/15/1979
From:	INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
References
RTR-NUREG-1437 AR, NUDOCS 9111110012
Download: ML20079M948 (134)

Text

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-ll p INDIANA & MICHIGAN POWER COMPANY

• DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 i

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Supplemental Report Demonstrating Compliance with Section 316(b) of the Clean Water Act A

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Submitted to the Michigan Water Resources Commission i.

September 15, 1979 k.4%y'I 9111110012 790915 PDR NUREO 1437 C PDR

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LO INDIANA & MICl!IGAN POWER COMPANY DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 O

Supplemental Report-Demonstrating Compliance with Section 316(b) of the Clean Water Act Submitted to the Michigan-Water-Resources Commission September 15, 1979

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( J; TABLE OF CONTENTS Page I. INTRODUCTION........................................... 1 II. REGULATORY REQUIREMENTS IMPOSED BY SECTION 316(b) OF THE CLEAN WATER ACT.......................... 7 A. The Burden of Proof Under Section 316(b).......... 10 B. Section 316 (b) Demonstrations for Existing Intake Structures................................. 11 C. Section 316(b) Cost Considerations................ 14 III. THE EXISTING COOLING WATER INTAKE STRUCTURES AT THE COOK NUCLEAR PLANT.............................. 16 A. Present Intake Structure and Circulating Water System Characteristics...................... 16

1. Design considerations ~and concepts........... 16

2. Operating prob 1 cms........................... 20

() 3. Construction of th; existing intake structures................................... 23 B. Environmental Impact Associated with Present Inteke Structures......................... 30  !

1. Fish larvae entrainment...................... 33

2. Analysis of-fish larvae entrainment.......... 34 C.- The MWRC Staff's Letter of March 30, 1979......... 38

1. Value of lost fish production due to Cook Nuclear Plant operation.............. 40'

2. Failure to consider and' evaluate uncertainties in the production foregone calculation......................... 42

3. Mortality estimate inaccuracies.............. 47

4. One hundred percent mortality assumption................................... 49 l

l 5. Compensation................................. 54 O

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TABLE OF CONTENTS

(Continued)

Page IV. ALTERNATIVE COOLING WATER INTAKE STRUCTURE DESIGNS................................................ 61 A. Screening Study................................... 63

1. Location..................................... 63

2. Capacity.................................... 75

3. Design and' construction...................... 80 (a) Stationary Screens...................... 80 (b) Perforated Pipes........................ 80 (c) ' Drum Screens, Rotating Disc Screens, Morizontal Traveling Screens and Inclined' Plane Screens.................. 82-(d) Filtration Type Intakes.................-82 (c) Trash Racks............................ 82 (f)

Behavioral Barriers..................... 83 B. Cylindrical Wedgewire Screens..................... 83

1. Existing wedgewire screen installations...... 83

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.2. Conceptual design for installation _

,, of cylindrical wedgewire screens :at -

the Cook Nuclear Plant....................... 90

3. Biological effectiveness of a cylindrical wedgewire screen intake...................... 99

4. Summary..................................... 107 l

C. Fine Mesh Traveling Screens...................... 108 j 1. Existing-fine mesh, center-flow screen installations........................ 110

2. Conceptual design for installation of fine mesh traveling screens at the Cook Nuclear Plant.......................lll

3. Biological effectiveness of fine (A

l U mesh traveling screens...................... 118 ii -

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TABLE OP-CONTENTS t

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EEEE-(a) ' Low-pressure screen wash System................................. 120 _

(b). Additional trash trough................ 120 (c) Jet pump (peripheral type)............. 121 (d) Smooth interior piping .

(i.e., fiberglass)...................... 121

..(c) Discharge structure capable of surviving the lake conditions....... 121

4. Summary............ ........................ 122 V. CONCLUSION............................................ 124 References-Cited Appendix A

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I. -INTRCOUCTION On December 27, 1974, the Michigan Water Resources

-Commission ("MWRC") issued to the Indiana & Michigan Power-Company (" Company") an authorization to discharge from the Donald C. Cook Nuclear Plant (NPDES Permit No. MI 0005827).

In accordance with section 316(b) of the clean Water Act, the NPDES Permit required, inter alia, that the Company perform a-study on the effects of the Cook Nuclear Plant's cooling water intake structures to show that the existing cooling water in-take design, location, construction and capacity reflect the best technology available for minimizing adverse environmental impact.

Pursuant to this requirement, on February 18, 1975,

.(]b the Company submitted a " Plan of Study and Time Schedule for Environmental Monitoring of the- Ef fects of Cooling Water Intake Structures at the Donald C. Cook Nuclear Plant." - On March 18, 1975, Messrs. Courchaine and Fetterolf-wrote to the Company commenting on the 316 (b) Stucy Plan and suggesting various .

changes. Following discussions with the MWRC Staff,on June '

19, 1975, the Company submitted " Comments Concerning: Plan-of Study _and Tims Schedule for Environmental Monitoring of the Effects of Cooling Water Intake Structures at the Donald C.

Cook Nuclear Plant by-Dr. John C. Ayers", which addressed the comments set forth in the March 18, 1975 letter. Based-on l

these submittals, the Company's 316(b) Study Plan was approved i

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(f. ioniJuly 8, 1975 (see letter from R. J. Courchaine to R. M.

Kopper, Executive Vice President, I&M).

i Because of the interrelated nature of the Company's section 316(b) demonstration and a parallel investigation being undertaken by.the company pursuant to section 316(a) of the Clean Water Act, the Company submitted to the MWRC a joint re-port on both studies. This document, entitled'a " Report on the Impact of Cooling Water Use at the Donald C. Cook Nuclear Plant",

was filed on January 1, 1977. In addition to the. data and analy-sis presented therein, the Cooling Water Report drew on data and analyses presented.by the Company.in numerous earlier studies of the Cook Nuclear Plant's physical and environmental impact, and, based on all the underlying studies, concluded that the location,. design, construction-and capacity of the Cook Nuclear Plant's= cooling water intake structures reflect the best tech-nology_available for minimizing adverse environmental impac;.

Following submittal of the Ccoling Water Report, representatives of the Company met with members of the MNRC Staff.

- to discuss the - Report. As a result'c1_that1 meeting, and further discussions over the telephone, certain additional' data and analyses.were submitted. On April-7,'1977, R. E..Basch wrote to Laurence Storch on the status of the MWRC's review of the 316 (b') d emons tration. In-that letter Mr. Basch-requested 1

-further data with respect to 1976 losses for larval fish.

Following submittal of this data, Mr. Basch informed the Com-pany that " adequate informatior. will be available to make the

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3-0 316 (b) determination. Therefore, if the 1976 data is furnished l and is complete, we will not request any additional information."

On April 18, 1977, the Company's consultant, Dr. David J. Jude, prepared a report containing, in part, the data requested in Mr. Basch's letter of April 7, 1977.

On November 29, 1977, a further meeting between repre-sentatives of the Company and the MWRC Staff was held to discuss tha company's 316(b) demonstration. The consensus reached at the November 29 meeting is recorded in a December 2, 1977 letter from R. E. Zahler to Mr. Basch. In accordance with the agree-ment reached at the November 29 meeting, the Company provided additional information to the MWRC cn December 16, 1977, and on February 3 and March 17, 1978. To complete the last portion of O the new work requested by the MWRC Staf f, another meeting was held on July 20, 1978. Mr. Basch's August 22, 1978 letter re-cords the agreement reached for providing the additional infor-mation then requested by the MWRC Staff. The initial part of this information was provided in early September, 1978, and in a September 21, 1978 letter to the Company's consultants, D. B.

Jester approved the algorithm and parameters proposed for use in the production foregono calculation. On November 21, 1978, the Company's consultants at the University of Michigan sub-mitted a report "On the Calculation of Production Foregone Due to Entrainment and Impingement of Fishes at the Donald C. Cook Nuclear Plant."

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Lon March 30, 1979, R. J. Courchaine transmitted'to the Company an initial position formulated by the MWRC Staff with respect to the Company's section 316(b) submittals. That initial position was that the design, location, construction and capacity of the Cook Nuclear Plant cooling water intake structures do not reflect the best technology available for minimizing adverse environmental impact. In view of this find-ing, the Company was requested to submit a supplemental report describing alternative intake designs or modifications to the existing intake structures, including an evaluation of the ad-vantages and disadvantages'of the alternatives considered.

A meeting was held on !!ay 21, 1979, between representatives of the MWRC Staff and the Company to discuss O_

the nature of this supplemental report. At that meeting the Company _ presented the results of its preliminary engineering-

-studies of.various intake structure alternatives. It was the

. view of1the Company's technical staff that there were no feas-ible -alternatives to the existing intake _ structures, and that those' structures did indeed reflect the best technology available for minimizing environmental impact.

At the request of the MWRC Staff the Company has under-taken to record its technical evaluation of the existing intake str'atures, as well as various alternative structures, in written form. This supplemental report represents that ef fort. - i Also included herein is a biological analysis of the posi-

< {]{ tion adopted by the MWRC Staff in its March 30, 1979 letter,

setting forth the grounds for the Company's disagreement with that position. In order to make this supplemental report most useful to the MWRC, the Company has attempted to draft the document so that extensive reference to earlier filed reports is not necessary.

Nonetheless, the Cooling Water Report submitted on January 1, 1977 contains much useful and relevant information, all of which nas not been duplicated here. On the basis of this supplemental re-port, and the other study plans, reports, and statistical informa-tion previously filed with the MWRC, the Cvmpany respectfully re-quests that, pursuant to section 316(b) of the Clean Water Act, the MWRC find the location, design, construction and capacity of the existing cooling water intake structures at the Cook Nuclear Plant reflect the best technology available for minimizing ad-O verse environmental impact.

The remainder of this supplemental report is organized as follows:

Section II " Regulatory Requirements Imposed by Section 316 (b) of the Clean Water Act" sets forth the Company's under-standing of the relevant criteria governing a section 316(b) demonstration and the legal implications of those criteria.

Section III "The Existing Cooling Water Intake Struc-tures at the Cook Nuclear Plant" describes the physical character-istics of the plant intake structures, summarizes the environ-mental impacts associated with those structures (with special emphasis cn1 larval entrainments), and presents a biological critique of the March 30, 1979 letter frem the MWRC Staff.

Section IV " Alternative Cooling Water Intake Structure Designs" presents the Company's technical evaluation of alterna-d

tives to the present intake design. This evaluation includes a brief screening study of all conceivable alternatives and a more detailed analysis of cylindrical wedgewire screens and fine mesh traveling screens.

Section V " Conclusion" is a short summary of the factors supporting the Company's position that the existing intake struc-tures at the Cook Nuclear Plant do reflect the best technology available for minimizing adverse environmental impact.

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) II. REGULATORY REQUIREMENTS IMPOSED BY SECTION 316(b) OF THE CLEAN WATER ACT Section 316(b) of the clean Water Act, 33 U.S.C.

S 1326(b) (1976), provides as follows:

Any standard established pursuant to section 301 or section 306 of thic Act and applicable to a point source shall require that-the loca-tion, design, construction, and capacity of cooling water-intake structures reflect the best technology available for minimizing adverse environmental impact.

Regulations implementing this provision were promulgated by the United States Environmental Protection Agency ("USEPA") , effec-tive as of May 26, 1976. See 41 Fed. Reg. 17387-90 (April 26, 1976) (adding 40 C.F.R. S 401.14 and Part 402). Subsequently, the Fourth Circuit Court of Appeals declared USEPA's section 316(b) regulations unenforceable and remanded the matter to the_ agency.- Appalachian Power-Co. v. Train, 566 F.2d 451 (4th Cir. 1977). USEPA has yet to reissue new section 316(b) regula-

-tions, although its recently revised NPDES regulations do include ~

_ provisions for criteria applicable to cooling water intake struc-tures under section 316(b)-of the Act. See 44 Fed. Reg. 32854, 32952 (June 7,-1979) (reserving Subpart I of.40 C.F.R. Part 125 for such regulations).

While the decision in Appalachian Power remanded USEPA's-section 316(b) regulations, 'the Court did so on the basis of pro-cedural inadequacies. Thus, the " Development Document for Best '

i Technology Available for the Location, Design, Construction and l

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-( ) Capacity of Cooling Water Intake Structures for Minimizing Ad-verse Environmental Impact" (April 1976) still represents the only source of official guidance as to the requirements of sec-tion 316 (b) . That document sets forth the following criteria for measuring a section 316(b) showing (Development Document at 176-77):

Owing to the highly site specific characteristics of available technology for the location, design, construction and capacity of cooling water intake structures for minimizing adverse environmental impact, no technology can be presently generally identified as the best technology available, even within broad categories of possible application.

Within this context, a prerequisite to the identi-fication of best technology available for any specific site should be a biological study and associated report to characteri=e the type, ex-tent, distribution, and significant overall en-(]) vironmental relation of all aquatic organisms in the sphere of influence of the intake, and an evaluation of available technologies, to identify the site specific best technology available for the location, design, construction and capacity of cooling water intake structures for minimizing adverse environmental impact. [ Emphasis add,ed.]

The Development Document further recommends that the re- '

quired evaluation of intake structures be done through the acquisi-l tion of biological data which identifies important, indigenous

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aquatic organisms, specifies their temporal and spatial distribu-tion, provides a description of water temperatures, documents organism swimming capabilities, and relates the location of the L intake with concern for the seasonal and diurnal spatial distri-bution of the identified aquatic organism (Development Document at 12-13, 177-78). The Company has undertaken such an analysis

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(95-139). Based on that analysis, it is cicar to the Company that the Cook Nuclear Plant intake structures have only a minimal impact on the aquatic biota of Lake Michigan and the area- im-mediately surrounding the plant. While the Company understands from Mr. Courchaine's letter of March 30, 1979 that the MWRC Staff may have reached a different conclusion, we believe that position to be erroneous for the reasons described below (see pp.

38-60, infra).

Moreover, the Company also has made an analysis which demonstrates that, as well as causing no significant harm, the plant intake structures, when measured against the technologies described in the Development Document, do in fact conform to the criteria recommended, and are indeed the best technology avail-O. able for minimizing adverse environmental impact to the-south-eastern basin of Lake Michigan (see-Cooling Water Report at 150-90). Mr. Courchaine's March 30 letter, while not contesting any ci the conclusions reached in the Cooling Water Report on.alterna-

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tive intake structures, criticizes the report for failing-to analyze technologies to reduce entrainment losses. Such an analysis was not included in the company's earlier 1977 Cooling Water Report precisely because precious little information then existed with respect to that issue. To the extent the MWRC Staff may have viewed the absence of such information as a shortcoming of the Cooling Water Report, this supplemental report corrects that deficiency by analyzing the information that has been de-veloped since 1977 and evaluating various alternative intake

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technologies which have been suggested since submittal of the Cooling Water Report (see pp. 6&123, infra).

-( )- Consideration of this new material, as well as a re-view of-the earlier analyses done by the company, confirm our initial view that.the existing intake structures reflect the best technology available for minimizing adverse environmental impact. In some of our discussions with the MWRC Staff, the Com-pany has perceived what we believe to be certain erroneous con-clusions with respect to various legal issues raised by section 316(b). In order to avoid future confusion, and so as to clearly alert the MWRC Staff as to the mode of analysis the Company be-lieves to be required by section 316 (b) , we outline below three central issues.

A. The Burden _of Proof Under Section 316(b)

Section 316 (b) places the ultimate burden of cersuasion

-- the so-called burden of proof -- upon the permitting authority, t

( and the MWRC thus bears that responsibility. Suppor~ for this p

conclusion comes from Decision of the General Counsel No. 63 (July 29, 1977).- There, it was held that "undcr Section 316 (b) EPA ~

(the general permitting authority) has the ultimate burden of p<isuasion and economic considerations are appropriate" (id. at 26). This conclusion ic based upon the view that the duty to implement section 316(b) f alls on the permitting authority and t:.ir duty requires that entity to define on a case-by case basis l precisely what is the best intake structure technolos:'. See-generally Decision of the Gcneral Counsel No. 41 (June 1, 1976).

In order to discharge this responsibility, section 316(b) requires I.

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the permitting authority to clearly summarize the legal and factual

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() basis for any decision rejecting a 316(b) demonstration. See

. Decision of the General Counsel No. 63, at 28-31 (July 29, 1977).

The basis for this requirement, in the. case of a section 316(b) demonstration, was explained by the USEPA General Counsel in the following terms (id. at 28-30):

An " elementary and fundamental requirement of due process in any proceeding which is to be accorded finality is notice reasonably calculated, under all circumstances, to apprise interested parties.of the pendency of the action and allow them to present their objections. " Reasonable notice is also part of the developing " common law" of administrative procedure. EPA accordingly is obligated to give-clear written notice of the basic factual and legal determinations which underlie the permit conditions

-at issue. The detail of the notice must be related to the complexity and significance of the issues.

Notice should be straightforwa.d so as to provide a clear explanation of EPA's reasoning. A staff n

v memorandum to the file, for example, which is subsequently released without explanation cannot satisfy EPA's obligation to provide adequate notice since it does not purport to be an offi-cial Agency rationale for a permit condition and it thus forces the permittee to guess at its significance.

B. Section 316 (b) Demonstrations for Existing Intake -

Structures i The statutory mandate that cooling water intake struc-tures reflect the best technology available does not specify a l

point in time when such an assessment is to be made. Obviously, L

l intake structure technology is constantly changing and what may represent the "best technology available" at the tLme of plant de-sign may no longer reflect the "best technology available" at the time of plant operation. Simple logic dictates that the require-() ments of cection 316 (b) be interpreted in a reasonable manner, l

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and a construction of that provision which would require con-tinuing modifications to an existing intake structure in order t'o reflect the "best technology available" is not a reasonable application of the statute.

This conclusion is supported both by the Development Document and the pr2 amble to the remanded section 316(b) regula tions. In this regard, the Development Document specifies that evaluation'of existing intake structures (defined as a structure in operation or upon which construction had commenced as of December 13, 1973) is to proceed on a modified basis (pp. 142-43 and 193):

Many existing intake water structures fall under the definition of a cooling water intake struc-(]) ture. Consideration of the factors discussed in this document will be required for existing as well as new structures. It is possible, however, that the cost of modifying an existing intake structure to comply with all of the best tech-

-nology discussed in this document may exceed the cost of designing and constructing a new intake structure _to comparable standards.

In determining the "best technology available" that is applicable to an existing structure, the degree of adverse environmental impact should be considered. An existing structure may be accept-able despite the fact that it does not conform in all details to the criteria recommended in this document if, as a result, environmental damage is minimal.

Consideration of the factors deccribed in this document will be required for existing as well as new structures. In determining the best technology available for existing structures, the degree of

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adverse environmental impact should be considered.

s An existing' structure may conform to best tech-i s) nology available despite the fact that it does not conform in all details to criteria recommended in this document. New structures can be expected

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(s to incorporate the most advanced technology avail-able to mir.imize adverse environmental impacts.

[ Emphasis added.)

These views are echoed in much the same language in the preamble to the remanded section 31G(b) regulations (41 Fed. Reg.

17388-89 (April 26, 1976)):

Scversi commenters recommended that the Development Document include specific considera-tion of the age of f acilities and other portin-ent factors which bear upon the degree to which costs are reasonable for particular establish-ments.

Decisions relating to the best technology avail-able are to be made on a case-by-case basis and may include factors such as ace.

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One commentor observed that the cost of modi-fying an existing intake structure to comply with certain specifications will generally exceed the cost of designing and constructing a new intake structure to those standards. On this basis, it is urged that the Agency expressly provide that an existing structure which has minimal environ-mental impact " reflects" the "best technology" regardless of whether its design, location and capacity conform precisely to the related criteria set forth in the Development Document.

The Agency recognizes that the cost of modifi-cation to existing structures 1.tay exceed that of constructing a new intake structure to comparable stande.rds. The Agency expects that higher costs associated with "retrofitting" existing structures, as well as the relationship of those costs to the remaining expected useful life of the facility, will be taken into account in determining the ex-tent to which t!.e specific technological measures described in the Development Document are avail-able at an " economically practicable cost."

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Since construction on the Cook Nuclear Plant intake structures commenced well prior to December 13, 1973, the MWPC's evaluation of the company's section 316(b) demonstration must proceed on the modified basis anticipated by USEPA.

C. Section 316(b) Cost Considerations Despite the fact that section 116(b) speaks of " cooling water intake structures (that] reflect the best technology avail-able for minimizing adverse environmental impact," it always has been the uniform construction of section 316(b) that eronomic considerations are relevant. As the legislative history accompany-ing the clean Water Act notes, "the reference * *

• to 'best technology available' is intended to be interpreted to mean the best technology available commercially at an economically practi-cable cost." 1 Leg. Hist. 264 (remarks of Representative Don H.  !

Clausen; emphasis added).

This view has been explicitly adopted by USEPA in its Development Document. It was there stated (pp. 177 and 193):

The term "best technology available" infers the use of the best technology available commercially ~

at an economically practicable 15ast. Considera-tion of the economic practicability of employing the best technology available also must be done on a similarly individualized basis. When determina-tions concerning cooling. water intake structures for_a_ specific point source within a particular industrial _ category.are being made, the Develop-ment Document accompanying effluent limitations

-and new source performance standards for that category should be referred to for specific factors that may be relevant to the consideration

, of economic practicability.

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Consideration of the economic practicability of installing available technology should be.part of an intake structure evaluation. The develop-ment document accompanying effluent limitetions and new source performaner standards for a par-ticular indastrial category should be referred to for factors specific to point source water for that category which may be relevant to the con-sideration of economic practicability. (Emphasis added.] ,

Moreover, this view also has been adopted by the United States Court of Appeals. In United States Steel Corp. v. . Train, 556 P.2d 822, 850 (7th Cir. 1977), the Court held:

[T]he company's complaint regarding EPA's failure to compare the costs and benefits of the various '

technologies available to reduce the adverse environmental impacts of cooling water intake structures comes too soon. No particular con-trol methods are required by the permit, and

() -- we trust that EPA will conduct a limited cost-benefit analysis once the information on which ~

an evaluation of the various technologies can '

be made becomes available. [ Emphasis added.]

The MWRC should, of course, follow a similar procedure in assessing the information included in this supplemental report. .

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III. THE EXISTING COOLING WATER INTAKE STRUCTURES AT THE COOK NUCLEAR PLANT '

o This section of the supplemental report describes the existing cooling water intake structures at the Cook Nuclear i Plant; it is divided into three parts. The first part provides "

a physical description of the intake structures and the factors  !

coresidered in the desigt..of those structures. Also included is a brief-explanation of the operational problems that have been encounterad to -date with the existing structures. This informa-tion is-provided in order to document the harsh-environment present on the eastern-shores-of Lake Michigan and the design constraints resulting from that environment. Finally, a descrip-tion of-the effort expended during construction of tha intake

() structures is included, so as to-advise the MWRC as to the scope of work that might be necessary if modifications requiring addi-tional in-lake work were ordered. The second part of this section summarizes the information previously provided as to the environ-mental impact associated with the Cook Nuclear Flant cooling water intake structures. This summary includes a discussion of both the statistical-information provided and the various models used by the company to assess and evaluate the statistical information.

! The third part of this section is a critique of the biological t

conclusions included in the March 30, 1979 lettor from the MWRC

Staff.

A. Present Intake Structure and Circulating-Water System g[ Characteristics

1. Desian considerations and conceots. In designing

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the Cook Nuclear Plant intake structures, the Company had to combine features which would provide a dependable source of f cooling water, would be able to withstand the severe Lake Michigan icing conditions, and would have a minimum impact on human and aquatic populations. The ultimate structure also had to be l worthy of licensing by the Nuclear Regulatory Commission and the  !

MWRC. The design settled upon consists of three intake cribs

-supplying water'to a common intake forobay through three 16-foot  ;

diameter corrugated steel pipes.

As described in the Cooling Water Report, the intake cribs consist of upturned, smoothly rounded intake elbows set in the lake bottom, surrounded by sacked concrete and riprap to prevent erosion. .The inlet to each elbow is completely surrounded O by an octagonal, heavy structural steel frame with bar racks and guides on all sides. The structure is designed fer protection ,

against ice floes and the entry-of large pieces of foreign ,

matter into the intake pipc. The bar racks and guides form an

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8-inch by 8-inch grill. The normal average cooling water velocity through the intake grills is 1.27 ft/sec. The top of i the structural frame is provided with a plate steel roof to pro-vent the formation of a vortex which would pull in floating objects from above.

Water flows from the intake structure through three 16-foot diameter, corrugated metal intake pipes to the screenhouse located on the beach. These pipes were laid in a trench excavated

.. in the lake bottom and covered with at least two feet of sand.

Water velocity through the intake pipes is about 6 ft/sec.

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The screenhouse is common to both reactor units and con- l

. tains the circulating water pumps, trash racks, traveling  ;

screens, essential service pumps, diesel-driven fire pumps and l associated equipment. i Cooling water passes from the intake pipes into the screenhouse forebay, through the trash racks and traveling screens, before reaching the circultting water pumps. The

-trash racks were constructed with 3/8-inch thick by 4-inch deep  ;

bars on 3-inch centers, giving an opening of 2-5/8 inches. The  ;

_ water velocity through the trash racks is approximately 1 f t/sec.

After passiig through the trash racks, the water is further screened by the traveling screens. A travo. ling screen is an endless belt-of screen baskets or frames ten feet wide O and approximately two and one-half feet high of Ilo. 14 W & M copper l wire with 3/8-inch- openings. The average water velocity through the screens is 2 ft/sec at the lowest expected water level in the screenhouse forebay. ,

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The traveling screen is motorized and geared to travel in a vertical direction. Leaves, trash, twigs and any other objects small enough to pass through the trash racks and be collected by the screens are removed from the screens by streams of high pressure water and sluiced into the trash fiume. This

. wash water is sprayed from a series of nozzles near the top of the screer travel and is supplied by the screen wash pumps. The trashfflume passes in front of all of the traveling screens, collecting. screen wash and debris from each. The debris removed t []f 3

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() by the screen wash is collected and disposed on land. The_ clean screen wash water returns to the screenhouse forebay in front of the traveling screens.

The screens on each unit are normally rotated and washed once every eight hours. Should the water level differ-ence across the screens increase to a predetermined value, an alarm sounds and the screen wash system starts automatically and runs until the dif ferenti,als- drop to normal or until tho screens

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are manually stopped. c.u. 9P"' 1 j ,, c From the traveling screen the water flows to the suc-tion of a nominal 230,000 gpm vertical, wet pit, mixed flow cir-culating water-pump. There are three circulating water pumps for Unit 1 and four for Unit 2. The circulating water flows to the intake tunnels which deliver the water to each unit's con-denser shells.

As noted in the MWRC Staff's March 30 letter, the Cook Nuclear Plant cooling water intake structures were not specifi-

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cally-designed to reduce or prevent the entrainment of ichthyo-plankton into the plant circulating water system.- Rather, the velocity cap intake'has been proven to reduce entrsinment of adult- fish (Weight, 1958; Schuler and Larson, 1974; Downs and' 1/

Meddock, 1974), and was employed for that purpose at the Plant.~

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Early work by Weight (1958) followed by quantitative work by l Schuler and Larson1(1974) reported 05-90% reduction of entrainment j of adult anchovys (Engraulis mordax); no freshwater species were tested. The velocity cap eliminates vertical currente, to which fish do not respond (Downs and Meddock, 1974;-Schuler and Larson, 1974; Weight, 1958), and produces horizontal currents which the O fish are able to detect and avoid at appropriate velocities. Downs

-- continued --

p

4

() Indeed, when the Cook Nuclear Plant was designed, no intake structures for once-through cooling systems were capabla of reducing the entrainment of ichthyoplankton. Nonetheless, as is indicated below (see pp. 30-60, infra), the entrainment of ichthyoplankton at the Cook Nuclear Plant does not result in  !

adverse environmental impact.

Y

2. Operatino problems. In addition to use of a }

-velocity cap so as to reduce the likelihood of fish entrainment and eventual impingement, the intake structures included several design features made necessary by the harsh Lake Michigan environ-

- ment. These included the installation of a heavy structural steel frame, octagonal in plan, which was installed on the lake .

[]) bottom over each intake elbow. The purpose of this frame was ,

to p: otect the intake elbows from large solid objects in the watect, particularly massive ice formations which frequently occur i in winter. In addition bar racks in both directions weresem-

- ployed to prevent the entry of large debris into the intake ,

pipes. Despite these design precautions, the Lake Michigan en- ,

vironment has on occasions caused operating problems with the in-take structures. The two most relevant examples are described belows (a) The existence of large winter ice floes was anticipated and planned for in the early design of '

1/ -- continued --

and Meddock (1974) recommend velocities between 1.5 and 2.0 fps.

The design velocity at the Cook Nuclear Plant is 1.27 fps at the 8-inch by 8-inch trash grill.

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I 21 -

() the intake structures. H-Beams were therefore located around the outside of the structure to protect the in-take funnel from damage by pushing the large ice floes around the structure until they were free to continue on their way. The last three winters have been ex-tremely descructive to this ice guard system and also '

to the 8-inch by 8-inch bar racks. Following the winter of 1976/77, 42 of the 192 ice guards were damaged or l completely ripped off the structure. During the winter of 1977/78,-75 of the ice guards were damaged or ripped off the-structure. In the fall of 1978 a 7/16" x 6" x 6" angle iron was wolded to the outside of the south structure ice guards at the midpoint along their

() length. This was done in an attempt to strengthen the ico guards by tying each one to the ice guards adjacent to it. During the winter of 1978/79, 88 ice guards were i damaged or ripped off.--However, only 16 of the 88 were

~

on the south structure which historically has been the most severely damaged. As a result, the center and north. structures will be fitted with angle iron af ter repair of the ice guards.

The severity of the ice conditions in Lake Michigan is further illustrated by the Company's ex-perience with the 8-inch by 8-inch bar racks. Several of those racks are designed with a shear pin such that if a large differential pressure exists across them LO or they are struck by an ice floe they will-fall in and relieve the pressure to allow water to flow. There are

- 22 - ,

() a total of 96 intake-rack sections with 36 designed to fall in. Annually all 36 racks fall in.  ;

(b) The fall and spring conditions around '

t the lake often bring severe storms with high winds.

5 A result of *hese stenas has been a large intake of  !

debris in the form of leaves, sticks, aquatic plants,  ;

algae, and occasionally dune grass. These conditions '

have put's strain-on the traveling screen systei.i and associated trash collection baskets. The original baskets for collecting trash were found to be inadequate during high load periods. As a result, a much larger basket was designed and built in 1978. The new baskets have a total volume of 300 ft.3 compared to the original design of 74 ft.3 -Nonetheless, even this augmented system proved inadequate for the storm experienced on April 5 and 6, 1979.- On that date the storm, accompanied by 80-mile per hour winds and 15-foot waves on the' lake, caused such a large influx of leaves that the traveling screen wash system was not capable of cleaning the screen completely before.it reached the top of the system and scarted back down on the opposite side. This caused the leaves on the screen to be washed off by intake water.

The trash and leaves _got into the main condensers and '

feedpump turbine condensers, partially pluggino-these condensers. This plugging caused a lower flow through the condensers and in turn caused the condenser back- '

10 pressure to increase. Unit 1 tripped at that time and [

-._-_._._m_.-_.._ . . _ _ _ _ - . . , , _ _ . . _ , _ . . _ . _ . . . . , . _ , . . _ . . .

() Unit 2 was brought down to 50% power so one feedpump at a time could be shut down and its condenser could be 2/

cleaned out."

3. Construction of the existing intake structures.

Substantial effort was expended by the Company during the ini-tial construction of the Cook Nucioar Plant cooling water in-take structures. Necessarily associated with this level of in-1ake construction was some level of environmental impact. Any requirement that further intake structure work necessitating additional in-lake construction be undertaken at the Coo ~ Nuclear Plant should consider the adverse impacts associated with such work. While the Company cannot now identify or quantify with

(]) any precision what those environmental impacts might be -- be-cause the company does not know what the MWRC might require --

they are likely to be of a nature similar to that experienced durin g the initial construction effort. As briefly described below, that ef fort included impacts due not only to the construc- _

tion and installation of the necessary piping and intake cribs, but also due to the construction of a " safe harbor."

As previously noted (see pp. 17-19, supra), water flows from the intake cribs through three submerged, parallel pipes to I/

In fact, the-trash impinged on the traveling _ screens becomes so great at times that off-site removal even becomes a problem.

During normal operation all trash removed from the traveling screens must be disposad of off-site. This is presently done by an outside contractor licensed to haul solid waste. During periods of-high volume intake of debris, and periodically during 4 (n) summer months for health reasons, trash must be removed from the site on a daily basis.

w o

I I

the screenhouse located on the beach. Each of the submerged in-take pipes is 16 feet in diameter and constructed from sectional corrugated plate. Each pipeline is equipped with two 36-inch diameter manholes, one located 6 feet from the screenhouse and one approximately 1,170 feet from the shoreline.

The intake pipes were assembled on shore into 40-foot lengths from corrugated plate steel sections. The lengths were then lowered by barge crane into dredged trenches in a continuous placement sequence. The trenches were dredged in the lake bottom to a depth of approximately 20 feet. After the intake pipe seg- ,

ments were lowered into position a backfill and cover operation was employed. Each of the 16-foot diameter corrugated intake pipes was overlayed with one foot of sand on top of which a filter O cloth (Laurel Erosion Control Cloth, Type #1) was placed. Over the filter cloth was placed a 2-foot minimum and 4-foot asximum of well graded riprap ranging in weight from 2 to 150 pounds. At _

least one-half of the individual pieces exceeded 75 pounds in weight. This backfill criteria was followed for approximately two-thirds of the pipe length; elsewhere the depth of pipe pro-vided sufficient cover.

At the far and of the intake pipes, located approxi-mately 2250 feet offshore, lake water enters the circulating water system through three intake cribs. Each intake crib consists of an upturned, smoothly rounded intake elbow set in the lake bottom, surrounded by sacked concrete and riprap to prevent erosion. The s

() inlet to each elbow is completely surrounded by an octagonal heavy

l l

s -

() structural steel frame to protect it from large ice floes.

This frame is buried in the sand up to its t ~~t point. Each intake crib is equipped with 64 iceguards provicing the ice 4/

protection.~

The massive size of the structure is illustrated in Figures 1 and 2.

This structural frame was erected on land and towed by barge to the construction area. Most of the welded and bolted connections were therefore made on dry land. The steel frames were lowered inte position by two cranes and anchored to the lake bottem at an elevation of 549'-0" in a 2-fcot bed of tremic con-creto.

The outer excavation line was backfilled with sind and the crib was surrounded with sacked concrete and riprap. Approxi-mately 12,600 tons of riprap were placed circumferentially about O the three intake cribs. The cribs are equipped with bar racks on the sides and a plate steel roof to prevent entry of large debris into the circulating water system. The plate steel roof is set atanelevationof5([f)'-3". 56B'3" Construction of the necessary intake pipes and struc-tures was initiated in the summer of 1972. As is apparent from

~

~3/

Each octagonal frame measures 72'-6" from face to face and 37'-3" in height (see Figures 1 and 2 for a visual aid in sizing).

To better describe the si:e of each intake crib, picture two

~

circles, one inscribing the octagonal frame (diameter 72'-6")

and one circumscribing the crib with a diameter of 79'-0". The majority of the structural ccmponents of each intake crib are wide flange sections measuring 14 inches in depth.

4/

~

The iceguards are W8 x 17 sections (a" deep wide flange sec-tions weighing 17 pounds per foot of length) connected to the supporting frame by means of an L4 x 3 x 3/8 (angle iron of 3/8" thickness with unequal leg dimensions of 4" and 3" weighing 8.5 pounds per foot) welded to 10" x 6" rectangular wall tubing.

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() the nature of this work, a great portion involved diving and dredging from barges as pipelines and miscellaneous structures were anchored below the lake bottom. The nearest permanent harbor to the Cook Nuclear Plant is located at St. Joseph, Michigan, which is 9.4 miles north of the site. 11aving to anchor at St. Joseph during a flash storm or handling materials and equipmec.t deliveries from that distance would have been undesir-able; therefore, construction of a safe harbor was necessary.

Permits for harbor construction were issued in July, 1970 and construction was initiated soon thereafter.

The work required the construction of a steel cheet pil-ing enclosure extending approximately 400 feet lakeward and measur-ing 946 feet in length along the shore. The harbor enclosure con-O sisted of double wall piling (MZ-27) in lengths of 30 and 23 foot which were sand filled and capped with grout. The harbor was dredged to a 10-foot depth and the dredged material was utilized as the sandfill betwqen the double sheet piping walls.

In order to determine the impacts that the safe harbor might have on beaches adjacent to the plant site, a monitoring na and replenishment sy stem was set up. A monumente?, baseline sur- ,fr vey was laid out along the base of the dunes and as close as pos-sible to the state ordinary high water line elevation of 579.8 feet, referenced to International Great Lakes Datum. The survey extended about one mile north and about five miles south af the temporary harbor. To the north, the survey monuments were placed r at 500-foot intervals. To the south, the nurvey monuments were

~.

}

l 29 -

O placed at about 500-foot intervals in the first mile south of the I

harbor, and at-about 1,000-foot intervals in the remaining four -

r.iiles. The placement was contingent upon being able to obtain the necessary easements. i Cross-section surveys of the beach were made at each l

monument, startiny from the high bluff and extending lakaward as follows: To the north, and within the first milo to the-south, the cross-sections were made monthly and extended to a depth of. l 25 feet of water referenced to International Groat Lakes Datum or [

to 2,000 foot from shora, whichever was tha shorter-distance.

Within the remaining four miles to the south, the cross-sections l were taken at-3-month intervals and extended tc the 3-foot depth of water contour. Those survoys were made prior to the installa-tion of the harbor and continued during the life of the temporary '

harbor, except when prevented by ice. ,

Vertical aerial, photographs, taken by a recogni:ed pro-fessional aerial photographic survey company, Abrams Aerial Sur-voy corporation of Lansing, Michigan, wero made of the shoreline at 1-month intervals during the life of'the harbor. Photo-  !

graphic coverage extended a minimum of ono mile north and five miles-south of the temporary harbor. In addition, constant re-P curding instruments for the water levelland wind velocity were installed-and automatic readings were taken for the life of the project.

i  !

Por beach nourishment and lake bottom restoration, ,

material from natural accretion, and sand from the dredging of the p pelines and harbor (provided the sand contained no clay

_a

i

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B

l (2) or other materials in amounts deemed detrimental by the MDNR or t

the Corps of Engineers) were utilized. Two pumps, each rated at j t

200 HP and 200 gallons per minute were employed to pump sand from i the northern side of the temporary harbor and discharge this f sand on the southern side of the temporary harbor, rach pump .

was capable of pumping 90 cubic yards of sand por hour. All sand that built up on either side of the cofferdam was pumped, by f t

one of the aforementioned pumps, to the southern side of the  ;

temporary safe harbor for replenishment of the beaches.

P Oopies of the surveys, aerial photographs, water level-and wind velocity data were sent monthly to the Michigan Depart-L ment of Natural Resources and the Detroit District, Corps of Engineers, for joint review of the impacts of the temperary harbor

)

and the sand replenishment procedure on the bench. Copies of all survey data were kept (ni file in the office of the Resident En-gineer at the Cook Nuclear Plant. Upon completion of the under- y water construction (intake pipes and cribs),'the temporary harbor was removed, and the beach and lake bottom at the site of the harbor were restored to the depth and bottom configuration.that existed prior to the construction of the harbor. Final reports and recorded data indicated both beach and bottom conditions were p stabilized. ,

i .

L B. Environmental Impact Associated with Present Intake.

- Structures l

f l The organisms in the lake relevant to the study of the O Cook Nuclear Plant's Ompact on the aquatic environment can be i

- T YWg"Sdr" FT W 9 4"T'n' F*r' W M'"" m MwwWF w w w-W' W F T

i divided into seven categories: phytoplankton, zooplankton, ben-thos, periphyton, fish eggs, fish larvae and adult fish. Monthly or seasonal collections of these organisms have been made from the open lake using research vessels. These collections allow measurement of species abundances in Lake Michigan and reveal any changes in abundance that might be caused by plant operation.

The-results of open lake collections are referred to as field data.

In addition to field data, it also is important to know the quantity of each kind of organism that is drawn into the Cook Muclear Plant cooling-water-intake system. Adult fish that enter i the- plant will be impinged on the 3/8-inch mech- traveling screens.

When the screens are washed, and an part of the monitoring program,

)

impinged fish have boen collected in a mesh basket and saved for t'

later analysis. . Fish eggs and larvae too small to be caught on the screens, pass through the condensers and emerge in the dis- i charge water. In a similar manner, phytoplankton, :ocplankton  :

and benthos drawn 'into the intake pass through the plant and exit with the discharge water. All of these organisms have been sampled in the intake forebay and at-the discharge bay by pumping-  :

up quantities of water'through a 3-inch pipe. All except phyto-plankton have been smgled byfiltering the stream -through plankton ,

nets; plankton samples have not been filtered. After an appropri-e ate volume of water has buenffiltered, samples were preserved

• i and returned to the laboratory for analysis. These collections ,

(][ are referred-to as entrainment samples.

l

32 -

O Thus, the monitoring program has yielded three types of data samples: field, impingement and entrainment. The types of collection used for each organism are summari:ed in the follow-ing tables Field Impingement Entrainment Phytoplankton X X Zooplankton X X Benthos X X X Periphyton X X Fish eggs X X Fish larvae X X Adult fish X X O Since both field and intake samples have been taken for each of seven types of organism, there are a total of 14 sample categor~

ies. Included within the Cooling Water Report are sections analyzing the impact of plant operation on these organisms.

Those sections describe the various monitoring regimes at the plant (pp. 78-94), cross-reference to the locations of the col-lected data (id.), and evaluate the biological significance of plant operation (pp.95-139).

Following submission of the Cooling Water Report, meet-ings between the MNRC Staff and Company representatives have L identified the losses associated with plant entrainment of fish larvae as a matter of primary concern to the MWRC Staff. The

() March 30, 1979 letter from R. J. Courchaine specifically idenfi-

33 -

O fies such lasses as the basis for the MWRC Staff's initial posi-tion rejecting the Company's section 316(b) demonstration (see ,

P. 40 , infra). In view of this concern, summarized below are  ;

the statistical data relating to entrainment of fish larvae, as well as the two different analyses performed by the Company of that data.

1. Fish larvae entrainment. Fish larvae are collected during a 24-hour period. This has been donc once a week during June, July and August and twice a month during the rest of the year.

The timing of these collections is designed to sample any fish larvae and eggs during. spawning activity which may occur. Most Lake Michigan fish spawn during the summer months, which accounts

() for the weekly sampling schedule in June through August.

For entrainment sampling the stream of water from the sampling pump has been filtered through a plankton net suspended in a barrel of water. Fish larvae were sorted by species and enumerated. Immediate larval mortality was not evaluated be- -

l cause of anticipated high sampling induced mortality.

I As reported in the Cooling Water Report (p. 92), data 1 from entrainment studies of fish larvae are discussed in Special Reports of the Gielt Lakes Research Division which include Jude, et al. (1975). The studies of entrainment sample and data analy-sis and the monitoring program also are discussed in the Semi-annual Environmental Operation Veports which include January-June 1975,-July-December 1975, January-June 1976, and July- ,

O' December 1976; preliminary data and monitoring results are I

1

l

- 34 -

() presented when available. A study of fish egg and larvae forebay stratification, a: comparison of mean concentrations of fish larvae in the field (lake) and forobay during certain periods of 1974 and 1975 are discussed in Jude (1975).

Subsequent to preparation of the Cooling Water Report, the Company has provided the MWRC Staff with further fish larvae entrainment data. This is included in submissions dated: March 16, 1977; April 18, 1977; December 16, 1977; February 3, 1978,;

March 17, 1978; and November 21, 1378. On the basis of this information it is possible to estimate the entrainment loss of 21sh larvae from operation of the Cook Nuclear Plant. Table 1 presents such data for the four major major species of ichthyo-5/

plankton entrained at the plant.

O 2. Analysis of fish larvae entrainment. The Cooling Water Report section on fish (see pp. 119-38) includes various methods for assessing the impact of plant operation on adult fish, fish larvae, and fish eggs. In each instance, the Cooling Water Report quite properly concluded that the effects of plant

~5/

The data presented in Table 1 were calculated from the observed mean concentration (#/1000m3) of larval entrainment for the years 1974 through 1976. In order to generate estimates (and confidence interval limits) for the total number of organisms entrained, the mean concentration (and its confidence interval limits) were multi-plied by the volume of water circulated through the plant at maxi-mum rating for Unit 1 -- i.e., 710,000 gallons / minute. Consistent with the Company's conservative philosophy in estimating environ-mental impacts associated with plant operation, the data over-estimate actual entrainment effects since the volume of water circu3ated through the plant during each day of operation is not at maximum rate. The upper and lower limits were calculated on the basis of a distribution-free 75% confidence interval around O the mean concentration, based on Chebyshev's theorem.

n

I 'able l'. Estimated oumbers'and mean wcInhts of . o and post larvae entialued at t he D. C. Cook th . er 4 uwer Plant between.1974 and 197(. .

75% Chebyshev i i

Interval Entimated of uelghtg Estisc.t ed Estimated Species Year. Total- I. owe r Upper. 1.arvae gx 10 - Number Blomass n

! 7 7 M ewi fe 1974 6.4603 x 10 3.6 x 10 9.371 x 10 Nd X/N Pro .03 4.9680 x 10 1.490 x 10

( 8 7 8 Post 4.45 1.492 x 107 6.64 x 10'  !

1975 1.05357 x 10 1.94184 x 10 1.92467 x'10

16*M7 X /0 Pro .03 1.017 x 10 3.05 x 10 i 7 7 7 l'os t' 4.45 3.687 x 106 1. 64 x 104 l

1976 6.12407 x 10 3.10853 x 10 9.23769 x 10

[42 4/#7X /O* Pro .03 1.337 x 10 l

' Post 4.45 4.08 x IGf 1.666 x 10 7.413 x 10.

Spottall 1974 1.227 x 105 0 3.683 x Jo 6

i Shiner 4l7 A /8' Pro .82 5.99 x 10 4.91 x 10 g ,

f 6 6 6 Post .91 3.217 x 10 2.927 x 10 8

. 1975 4.9639 x 10 1.1725 x 10 -8.907 x 10 w 6

• l Pro' .82 3.941 x 10 3.23 x 10 6 4 6 I*os t .91 1. x 10 9.305 x 10 8 1976 1.0429 x 10 1.14 x 10 2.6265 x 10 2

7.843 x 10 5 2

Pro .82 '6.431 x 10 Post .91 2.536 x 10 5 2.354 x 10 2

6 6 7 l Rainhou 1974 8.97 x'.10 1.88 x 10 1.61 x 10 I Smelt 2 4

Pro .37 10 l'os t 8.71

.2.597x10f.9.51x 3.373 x 10 2.938 x 10 6 5 6 l 1975 1.22 x 10 1.87 x 10 2.53 x 10 I

! Pro .17 3.489 x 10 5.932 x JO 5

5 6 Post 8.71 8.711 x 10 7 587 x 10 f'

. . 1976 7.881 x 10 0 1.82 x 10 5 2

} 0.74 ^ (05- rro .17 7.881 x 10 1.340 x 10 j Post 8.71 0 l t

Yellow 1974 0 0 0 7

Percle 4 $

1975 7.63 x 10 0 2.288 x 10 4 g Pro' .91 7.63 x 10 6.943 x 10

, Post -

0 0 3 1976 0 0 0 l

4- ,

l Weight s and members of pro-ardt ' post-larvac were <lerived.

1 - -. _ _- . _ . _ . -- - - _ _ . __ . _-_-i

I i

l operation were insignificant. One method used to quantify this conclusion was a simple " thought experiment" (see pp. 131-33).

As explained in the Cooling Water Report (see p. 99), this thought experiment was solely for illustrative purposes. It was not intended to be a rigorous analysis of actual in-lake impacts, but, instead merely was designed to give some numerical indica-tion of the very small effects plant operation was having on the lake biota.

With respect to larval entrainment, this thought experi-ment provided a simple analytical tool to convert the Company's best estimate of losses from larval entrainment into an estimate of lost salmonid production. The Cooling Water Report (see pp. 131-32) used as a starting point for the thought experiment an average O daily estimate of 612,000 larvae entrained, or 2.33 x 10 8 larvae 6/

entrained per year.- This number was then multiplied by a probably optimistic, and therefore censervative, natural survivnl rate of 0.002 (two per thousand of each year's hatch survive to adulthood), giving 466,000 adults from these larvae. It was then again conservatively assumed that these adults would have been "mean alewives" (heavier the "mean smelt" or "mean sculpin"),

i and the number was thus multiplied by the 0.030 kg per "mean ale-L wife" to give 17,708 kg of alewife as the estimated yield of these larvae. At 10% production efficiency, this weight of alewife could conceivably have produced 1,771 kg of salmonids. Since all

~6/

Data taken from: Jude, D.J. 1977. Entrainment of Fish Larvae l O; and Eggs on the Great Lakes, With Special Reference to the D.C.

Cook Nuclear Plant, Southeastern Lake Michigan. University of Michigan, Great Lakes Research Division. Contribution No. 202.

37 -

() the larvae entering the plant were conservatively assumed to be killed, this weight of salmonids was an estimate of production lost due to the operation of Unit 1; multiplying by a ratio of 2.32 to assess 2-unit cooling water flow, yielded 3,542 kg as an estimate of lost salmonid production.

The Company believes that this thought experiment, when evaluated as a part of the entire analysis set forth in the Cool-ing Water Report, provides a fully adequate basis on which to assess the impacts of larval entrainment due to plant operation.

Nonetheless, the MWRC Staff has raised concerns during meetings with Company represente.tives that the thought experiment did not properly consider certain factors (in particular, the loss in larval growth which could be expected prior to natural mortality),

O and, therefore, was inadequate. While the Company did not, and still today does not, agree with this assecsment, it was agreed that further work would be performed to provide an alternative basis for assessing the impacts from larval entrainment.

This further work took the form of developing an al-gsrithm, including the estimation of necessary input parameters, which could te used to calculate a projection of fish production foregone in Lake Michigan as a consequence of 17 "l entrainment and impingement at the Cook Nuclear Plant. This report was sub-mitted to the MWRC Staff on November 21, 1978. Because the ini-tial MWRC Staff position set forth in the March 30, 1979 letter relies so heavily on this production foregono calculation, a com-plete copy of the report is included herein as Appendix A.

)

38 -

() What the production foregone calculation does is pro-vide an alternative model for evaluating the impact associated with larval entrainment at the Cook Nuclear Plant. The results of this alternative model, expressed in terms of production fore-gone due to the entrainment and impingement of alewife, spottail shiner, rainbow' smelt and yellow perch larvae, are summarized in Table 2. The-estimate of biomass lost from this calculation is approximately 2 to 3.5 times higher than that estimated by use of che thought experiment (Rago, 1978). However, the coinpany does not believe that the production foregone calculation-provides a better or'more accurate evaluation of plant impact than the thought experiment calculation. Rather, both models provide relevant in-formation that should be considered in the ultimate evaluation of O the Company's section 316(b) demonstration. It is the considered opinion of the Company's consultants at the University of Michigan '

that, regardless of whether one evaluates just the thought experi-ment calculation, or just the production foregone calculation, or l

both models, the impact due to larval entrainment on Lake Michigan biota from plant operation is negligible.

The initial position of the MWRC is at odds with that' conclusion. We believe this position of the MWRC _ Staf f is due, l l

in part, to certain errors in interpretation of the production foregone calculation. Those errors are discussed in the next part'of this-section.

C. -The MWRC Staff's Letter of March 30, 1979 r

() As alluded to earlier, on March 30, 1979, the MWRC Staff

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l Tat 2 O O r,, eesage of tot al pod.rt tom ( es t .el t. .s s rl*

O Fes ces t ege of tot al remJact ies f actual bicense 8, ..t ge.s ea pe,J.c t',ee) . et a lbas ed by eeth stege t.g. . l se -a plos ess aeesed preJaction r )g coet a lbas ed by each stage / age class spettall es.l ese by year .

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~~

_~~ 2 .~_. 2 : ~. _

1973 1914 19f% 8916 1974 1973 1976 StasetA;e (2) 5tage/ Age 1973 (Z) #1) (1)

Cless (1) (Z) (Z) (2) Cines

• 12.3) 21.76 15.49 19.66 61.39 15.45 r r e-j a r,se 6#.66 Pre-l=rwae 0

• 86.8) 76 16 O 81.20 31.30 8).70 r..t-la ..e *

• O rost-leewee o 31.8 95 I .06 .0) .21 .86 0 33.8 .32

• I .06 .01 I

• .38 .70 L es I

O # .33 .0$ II

• .30 .37 5.47 It

• .02 .3I .12 It!

• .38 .42 2.17

1. 12

• .04 .94 .21 av * .06 .37 .92 l IV y

• .0%  !.17 .26 )

W

• .02 .45 .Il 46 I 95 282 vt

.01 .37 .05 &cemal Riomans Og)

.33 164.5 5983.84 I S 24 . s't vil rats.ated Fred ction Og) l 466 5532 2476 r Arteal Stomans og) <.1 .69 16% 3 62 27 7 19 1st lested Fredwet ton Og) 0.30 121940 180492 323488 DatS=( b)

A III' F .Il  !&S 3 'URI N4 690.9 12.6 118.3 Total reoJuettem '-

a,sgo( ) --

A 0.36 322406 186024 327964 Total FreJ=cti6e (bs) i w

c I

3.,

retr entage of to'al prodecs 8.e (4< t =4 3 b a.w. t.

Fes cent age of ts.tal pp.t ction (a.snel ble=ess plue ~ e s taated productleel tes e s tb=ted by eacle stagelage ela+a .E ent seat ed penduction) cont rII ted by eacts stage / age class of yellow perch by year. .

retabow smelt by year. -_ __

1973 1974 1975 1976 1974 1975 1976 st,ge/pge Stage / Age 1973

(*) (I) (2) (2)

(Z) (2) (2) (1) Class _ _ _ . _ _ _ _

Cle s _ _ _ _ . _ _

G # 38.10 &

e 3 . t:9 .26 3%.S rie-laswee e b a re-l as wee O O G

• 98.70 97.77 0 rest-nasede 10.26 12.2%

rost-larvae * .!O 1.28 0 63.69 36.30 o

3).88 2).54 30.33 29.15

• .00 .87 24.22 1 11 tm)

.32 12.$5 23.61 I

• 33 35 31 II 6.12 Il 1.22 7.8% 2.67

• * .37 12.78 Ill 8.11 llt 12.78 .77 6.28 5 28

• * .32 Ir 6.62 Ir y .87 7.8% 4.80 O 6.28 2.73 2.92 0.16 3) 49 21 vi A< t wal a t ===.s Og) o 3.14 1.46 1.54

.03621 !?)2S 43E8 $1.27 vil t.assmated read ction (6g) 7 1.45 20 184 L3t

.22 323.05 93.2) 8.90 Act.at 815.aass Os) 1855.74 Ratio ( 3 ) ^

Estimate 4 reeJ ctive og) 16.21 4).12 126).37

'A 'All 78 3 P

.20 li358 14.t el Fe eJactive O g)

_ _ _ . ~____ _ .

-- g. g,( 3 ) II 19 2,19 1.29 g_t4 A

17.46 6).22 1647.11 tell h Total trod css == O cl _ _ _ _

Actant If arness

, g .. e g,2,, Ig, D

1. le s s t h== . 012. g. - rst sotal Prohrt hs L

i

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transmitted to the Company their initial position rejecting the  ;

Company's section 316(b) demonstration. That letter identifies two specific bases for this conclusions first, that the design and construction employed in the intake do not reflect best .

i technology since there are several alternatives which have a sub-  !

stantial likelihood of reducing entrainment losses; and second, .

that the loss of fish (especially larval stages), as shown by the-production foregone report, is not acceptable. The first of these ,

points is dealt with in section IV. - As to the latter point, the i

company strongly disagrees with the conclusion urged by the MWRC Shaff. There are-nignificant errors in the letter involving mis-understandings,of relevant ecological principios and misinterpre-tat 3nns of data. Our discussion below is organized into five

.( ) topics.

1. Value of lost fish production due to Cook Nuclear ,

Plant operation. The MWRC Staff letter states that the annual loss of' fish produ' sn for 2-unit operation'is 672,710'kg for - i I the period 1974-76 This forage fich figure is assumed to be  ;

eaten by salmonids and converted to salmonid flesh at a-6:1 ratio.- The resulting loss is projected as 112,110 kg of lost salmonid production. A dollar figure of $20 to $33 per kg of lost salmonid production is used to calculate'a numerical loss of

$2,242,374 per year.

L Since yellow perch and spottail shiners are not usually  ;

part of the salmonid diet (see Table 3), these species should not j p

v be included in the foregone production value which is used'to- -

L t

O

)

b Tabla 3 Summary of Fish Eaten by Salmonids Collected During -

1973 to 1976 From Southeastern Lake Michigan (Jude, pnrs. comm.)

x Predator Prey Number O Species of Storachs Alewife aeinbow Smelt Stimy Sculpin Seatte11 Other Shiner Species Brown 109 78* 5 23 12 4 Trout (72)** (5) (21) (11) (4)

Rainbow 11 10 1 1 0 0 Trout (91) (9) (9) - -

4 Lake 243 205 24 6 10 4 >

Trout (84) (10) (2) (4) (2)

Chinook 17 14 4 0 0 0 Salmon (82) (24) - - -

Coho 144 123 32 4 3 1 Salmon (85) (22) (31) (2) (1)

• Occurrence of one or more of the prey species in a given "

salmonid's stomach,

• • Percentage of stomachs containing the prey species.

O

estimate the foregone production of salmonids. This reduces the year, 2-unit average from 672,710 kg to 652,671 kg.

In converting forage fish biomass to salmonid biomans the MWRC Staff assumes that 100% of the estLmated alewife produc-tion foregone is consumed by salmonids and that 100% of the fere-gone salmonid production is harvested by sport fishermen. These assumptions are obviously invalid. Frequent alewife die-offs and

,. dead salmon in Lake Michigan tributaries following their spawning truns attest to the fact that both assumptions are invalid. There-fore, the MWRC Staff's cost analysis is in error and should be re-

placed with a more appropriate cost analysis. However, for com-parison-purposes the production foregone, without yellow perch and spottall shiners, converted to dollars of salmonids by the MWRC

(): Staff's method is $2,175,570.

2. Failure-to consider and evaluate uncertainties in

-the production foregone calculation. The MWRC Staff failed to consider and evaluate the uncertainties associated _with the pro-

~

duction foregone model. This shortcoming is most apparent from the .f ailure of the MWRC Staff to qualify its conclusions. Thus at the bottom of page one of the March 30_ letter, and carrying over to the top of page two, the MWRC Staff simply and unequivocally states that "[t]he annual loss of fish production based on two-unit operation of this f acility averaged 672,710 kilograms (kg) for the period of 1974-1976." Drafted in this manner, the MWRC Staf f's statement gives the misleading impression that the "an-

{) nual loss of fish production" is an observed quantity. In fact, however, that value is a mere estimate based on a simplified

i l

l 43 -

(I model using certain assumed input parameters. The production foregone report described in detail the variouu assumptions used and attempted to quantify some of the uncertainty resulting from these assumptions. The March 30 letter neither recognizes these

-assumptions nor gives any indication that the MWRC Staff evaluated their impacts in reaching their initial position.

Despite the MWRC Staff's unwillingness to address the issue, the f act remains that all moduls are merely a means of organizing and structuring information. Models describing eco-logical events or concepts usually present a simplified view of the system being described. This is true of the model used to-predict foregone fish production due to impingement and entrain-ment at the Cook Nuclear Plant. In recognition of the limita-tions of models, Rago (1978) listed and explained the assumptions and qualifications made while developing the production foregone model. All of these items were ignored by the MWRC Staff. Rago (1978) listed five factors which introduce biases into the fore-gone production model. Within his report, and in subsequent cor-respondence with the Company, Rago elaborates on each of the five factors.

L First, fish have not been aged as part of the environ-mental studies at the Cook' Nuclear Plant; consequently a site- -

specific age-length key is not available. Age frequencies were.

~ determined by examining length frequencies of cumulative larvae entrainment samples. Larvae less than a certain length were l 4

._ called prolarvae and larvae greater than that length were called postlarvae.

l O Second, the total weight of fish impinged by 10-mm length class was not determined, which necessitated use of a length-weight regression estimate. Without this information, there is no pcsitive way of knowing how actual losses are dis-tributed over size and year class.

Third, mortality rates have rarely been estimated for Lake Michigan adult fish populations. Early life history mor-tality rates derived from the procedures outlined in Goodyear (1978) _ varied greatly from estimates reported by other agencies.

The egg to age I survival rate used for production foregone estimates for alewife was 5.2%. Nalco Environmental Sciences (1975) estimated egg to larval migratory stage survival to be 0.06% for alewife populations in Lake Michigan near the Zion O Nuclear Plant. Kissil (1974) estimates only 0.00131 survival from egg to young-of-the-year anadromous alewives. Sensitivity analyses presented in Rago (1978) showed that production fore-gone estimates were most affected by changes in survival rates between _ postlarvae and young-of-the-year for alewif e, spottail shiner, and rainbow smelt. Changes in the estimated number of entrained postlarvae of these three species also had a large effect on the production foregone estimate. The sensitivity analysis for yellow perch showed that changes in survival be-tween life stages from prolarvae to age III resulted in fairly constant changes in production foregone across life stages.

i Changes in weight of yellow perch for life stages from age III to V had the greatest effect on production foregone. The differ-

{}

cace between yellow perch and the three other fish species was l

) that very few yellow perch larvae were entrained; most of the lost yellow perch production was due to impingement. The lack of adequate survival data has a tremendous effect on the pro-duction-foregone. Rago (personal communication) states produc-tion foregone is extremely sensitive to the partitioning of mortality among prolarvae, postlarvae, and juveniles. For a fixed first year survival rate, the production estimate can vary as much as a factor of 9' depending upon the partitioning.

Fourth, due to sampling gear problems, mortality of larval fish has rarely been estimated directly. Indirect methods have generally been used. These indirect methods are not as accurate a measure of mortality rates as the direct measurement.

The importance of accurate mortality rates for ecrly life stages becomes more and more important as the foregone production for 7/

each succeeding-year is calculated.~ The uncertainty of the extrapolation increases with the period of extrapolation. It-is impossible to estimate exactly-this uncertainty, but it is un--

doubtedly large. ~

The confidence bounds for a univariate time series model, for example, are-quadratic functions of time.

7

"/

wife, The temporal pattera of production foregone estimates for ale-sentedspottail in Tableshiner,

4. The yellow perch, and rainbow smelt is pre-sequence of losses for all species are similar for the period 1974-1976. About 70% of the alewife and yellow perch-losses are predicted to occur within two years of-

.the actual time of entrainment and assumed mortality. Most rain-bow smelt and yellow perch estimated production losses occur three or more years after the time mortality actually occurred. These numbers are important since the confidence in the prediction de-creases as the length of the forecasting period increases, i.e.,

.O production losses occurring within one year of actual loss are more "certain" than losser occurring at a later time.

Table 4 Summary of Temporal Pattern of Production Losses for each Species by Year Year of Percent Loss by Years from Present Species Loss 1 2 3 4+

Alewife 1974 30.2 38.8 24.3 6.-

1975 35.5 39.5 13.1 12.0 1976 27.9 45.3 16.1 10.[. .

, s Spottail 1974 16.2 16.1 45.7 22. E

• I t Shiner 1975 16.1 28.3 33.5 22.1 '

1976 23.0 31.1 30.0 16.0 -

Rainbow 1974 7.0 17.7 44.4 30.9 Smelt 1975 11.3 11.6 46.7 30.1 1976 17.1 16.6 38.2 28.L Yellow - 1974 33.0 32.3 19.9 14.0 Perch 1975 37.0 32.5 17.3 13.2 1976 45.0 30.9 15.6 6.3

, i

- 47 -

.Therefore, _ confidence bounds on the production foregone estimates L(]J are likely to be very large.

Fifth, mortality and growth are dynamic processes which change in response to intra- and inter-specific relationships as well as to environmental changes. Mortality rates from other studies on fish communities in other waterbodies or at different times are of little relevance to the Cook Plant study.

3. Mortality estimate inaccuracies. The third caveat described.in the previous section related to the inaccuracy as-sociated with the mortality estimates made in the production fore-gone report. In order to quantify the impact of these inaccuracies

-on the production foregone calculation, the Company's consultants at the University of Michigan reran the model with more realistic O mortality estimates. These calculations show that inaccuracies in mortality estimates contribute a significant error in the produc-

-tion foregone calculation for alewives.

Survival estimates used in the foregone production re-i -

port.were very high. Alewife survival rates from prolarvae to y age I were 5.2% in the foregone production report (Rago 1978).

This is nearly 4,000 times the_value reported by Kissil (1974) and i nearly-87 times-greater than that used by Nalco Environmental Sciences (1975) (Ayers, personal communication). Using a 1.0%

survival from prolarvae to age 1 instead of the 5.2% or the 0.0013% survival. reported by Kissil (1974), alewife foregone pro-duction estimates decreased by between 71% and 77% during 1974

/~T through 1976. Table 5 shows the original estimates and the

,V

(

V) -

Table 5 ccr@arison of Original Production Foregone Calculations with Production Foregone Calculations Based on a Survival Pate fran Prolarvae Through Age 0 of 1.0%

(Rago, personal amuunication)

Species Year Production Estdrates Percentage

• change (kilocrans) frczn original es-Original Esticate Revised Estinute timate Alewife 1974 321940 73233 - 77.25 1975 180492 52704 - 70.80 1976 325488 73586 - 77.39 O

Yellow 1974 44 34 - 21.39 Perch 1975 1263 971 - 23.15 1976 1155 1061 -

8.17 Rainbow 1974 17325 8382 - 51.62 Smelt 1975 4568 2022 - 55.74 1976 51 200 28S.72**

Spottail 1974 165 41 - 74.87 Shiner 1975 5916 1609 - 72.80 1976 1524 453 - 70.30

'* Calculations made using data with the appropriate significant digits.

• • The percentage change is positive since the 1% sunrival rate is higher than the first year survival rate calculated fran field data.

-A v .

49 -

revised estimates of production foregone. The data include 1974 through 1976 estimates for alewife, spottail shiner, rainbow smelt, and yellow perch. Original estimates of production foregone due-to entrainment totalled 859,931 kg for the four species aver the 3-year period, the revised estimate is only 214,796 kg, or 24.9%

of the original estimate.

The 214,296 kg value based on the 1% survival rate from

=

prolarvae to age I, is a more representative estimate of foregone production due to entrainment at the Cook Nuclear Plant than that initially reported in the production foregone calculation. . Extra-polating the revised foregone production estimate to an average annual loss for 2-unit operation, a value of 165,722 kg is ob-To determine the average annual production. foregone of

{ tained.

salmonid prey, yellow perch and spottail shiners were deleted,

-and a-value of-162,498 kg/yr was obtained. Applying the MWRC Staff analysis to the foregone production of 162,498 kg/yr, yields an estimated-27,083 kilograms of salmonid biomass lost. At the MWRC Staff's estimate of $20/kg, this salmonid biomass represents a S541,660 loss to sport fishermen -- or 75.8% less than alleged by the MWRC Staff,

4. One hundred percent mortality assumption.. Perhaps-the most significant comment regarding the MWRC Staff evaluation of the entrainment associated with Cook Nuclear Plant operation is that all reports and analyses supplied to the state have been based upon an assumed 100% mortality for all entrained larval

() fish. Until recently, entrainment sampling methods were in-

+,sp. ---oge = -w p.iv.-- --puw - , - - - -

g-+- g a--y g -

9- --

.-g%v

. . .-.. . - -- _ - _ - - . . . . - . . . . _ = . - . . . .

O- _ appropriate for live / dead-studies at power plants. -Plankton nets cannot be-used in the intake and discharge forebays at the Cook Nuclear Plant because water velocities are too low. Pumps used for entrainment sampling can also cause mortality, thereby intro-ducing error into the mortality rate calculations. However, recent developments in sampling methods have produced reliable power plant entrainment mortality data from power plants in the United States and Canada (Ecological Analysts, 1979; attached as Appendix B).

Some of the more intensive sampling has taken place at four power plants on the Hudson River. Fish larvae survival rates for several species of fish have been reported for the Lovett, Danskammer Point, Bowline Point, and Roseton Plants. Table 6 sum-marizes some of these data for Clupeidae (alewives and blueback horring) survival at these four plants (Cannon, et al., 1978).

Clupeidae larval survival rates.were between 33 and 54% in samples collected from -.the intake _ at water temperatures between 15.0*C and 27.5'C. Mortality rates at the discharge were only slightly' higher than the intake.when discharge water temperatures were below 30.0*C, At Danskammer Point and Roseton, however,

-the differences were statistically significant. A critical re-view-by Ecological Analysts (1979) of power plant live / dead studies sboved a rsnge of survival rates for Clupeidae. Table 7 shows Clupe!.dae survival rates as low as 13% to as high as 77%.

L Direct extrapolation of this.entrainment mortality data

}{} from Hudson River sited power plants to the Cook Nuclear Plant on Lake Michigan-is not easy. Many environmental factors should

(

~

< 1 O

Table 6 Alewife and Blueback Herring Survival at the Intakes (I) and Discharges (D) of Four Power Plants on the Hudson River. (Adapted from Cannon et al., 1978)

Initial Life Temperature Number Proportion Plant. Stage Station (C) of Fish Surviving af Lovett- -Larvae I 15.5-25.5 338 6.33 D 19.0-29.9 396 0.33 D 30.0-32.9 35 0.09*/

D 33.0-35.9 19 0.05[/

muskmamr Larvae I 20.0-26.0 200 0.36 Point b/ ~

D 19.0-29.9 285 0.21*/

D D

30.0-32.9 36 0.11[/

33.0-35.9 5 0.40 Juveniles I 21.5-26.0 33 0.27 D 29.0-29.9 41 0.19 D 30.0-32.9 24 0.25 Bowline Larvae I 18.5-26.0 70 0.39 Point c/ ~

D 19.0-29.9 73 0.34 D 30.0-32.9 6 0.17 D 33.0-35.9 19 0.00*/

c/

Roseton~ Larvae I 18.7-27.5 1,518 0.54 D 19.0-29.9 871 0.30*/

D 30.0-32.9 425 0.077/

D 33.0-35.9 174 0.0l[/

Juveniles I 17.0-27.0 498 0.64 D 29.0-29.9 153 0.35*/

D 30.0-32.9 95 0.13*/

D 33.0-35.9 47 0.00[/

a/ Data from 1976 b/ Data from 1975 c/ Data from 1975 and 1976

(])

• / Significantly lower than in:nke proportion

!}-

Table 7 Entrainment Survival Estimates -- A Summary Based on Critical Review of the Literature (Adapted from Ecological Analysts, 1979)

Power Life Entrainment Plant Waterbody Taxon Stage Survi"al* (%)

Connecticut Connecticut c~ lae <l5mm 29 rs Yankee River >20mm 13

(_)

Bowline Hudson Clupoidae Larvae 77 Point River Roseton Hudson Clupeidae Larvae 29 River Lovett Hudson- Clupeidae Larvae 57 River .

Indian Hudson Clupeidae Larvae 40 Point River Danskammer Hudson Clupeidae Larvae 56 Point River Ginna Lake Alosa <15mm 23 Ontario pseudoharengus

• Survival in the absence of' thermal effects. Values represent annual estimates or means of annual estimates for those studies conducted for more than one year.

I 53 -

O- be considered when extrapolating survival data from one site to another (Dahlberg 1979). Pressure changes, discharge water temperature (Schubel 1975), and the presence of biocides have been shown-.to affect larval mortality rates. Life stage, water turbulence, and other stresses or factors are expected to affect l mortality rates. Ecological Analysts (1979)- states that salinity affects survival rates for Clupeidae. Entrainment survival rates:  !

1 averaged 26% with a range of 21 to 56% in fresh water and averaged '

52% with a range of 40 to 77% in brackish water (Ecological  ;

Analysts, 1979).

No one plant where entrainment mortality has been studied has all of the same conditions which exist at the Cook

-Nuclear Plant. Studies on the same fish species, alewife, at C)s a plant with a high velocity discharge similar to the Cook Nuclear Plant (Bowline Point on the Hudson River) showed that 77% of the entrained larvac survived plant parsage. The Cook Nuclear? Plant cooling system has a pressure change regime similar to the Roseton Plant on the Hudson River, except that entrainment duration is much shorter at Rosecon. Cook Nuclear Plant entrain-4

' ment-duration was shnilar to the Indian Point Pla.it, but the 7ressure changes are somewhat larger at_the Cook Nuclear Plant than at Indian Point Plant. Clupeidae larvae' survival rates for the-Roseton and Indian Point Plants were 29 cnd 40%, respectively

~

(Table 7) .

Since no single power plant has all of the same condi-t tions which exist at the Cook Nuclear Plant, the best estimate

({}

of the expected survival rate at the Cook Nuclear Plant would be between the extremes of those plants which are similar. The

lowest and highest survival rates were reported for plants sited on-fresh water, 21 and 56%, respectively; considering pressure changes and entrainment duration, the survival rates were be-tween 29 and 40%.

5. Comoensation. A final error in the MWRC Staff's letter is the failure to consider the effects of compensation.

Compensation as an eJological concept has been discussed and re- )

lated to power plant impacts (McFadden, 1977; Goodyear, 1977; Christensen, 1977). There is no doubt as to the validity of the concept. Yet, the MWRC Staff's assassment of the Cook Nuclear Plant impingement and entrainment impacts on Lake Michigan fish lacks any consideration of compensation. The intent here is not

() to conduct a complete evaluation of the Cook Nuclear Plant's effects in light of compensation, but to attempt to place compen-sation into perspective as it relates to the fish populations affected by the plant.

CompensationLis defined as the sum of all density- -

dependent processes that act to stabilize the population (Goodyear, 1977). McFadden (1977) states that only direct density-dependent processes are compensatory; direct density-dependent processes are those which reduce population growth at high densities and in-crease population growth at low densities. These processes, many of which have been-identified, act to increase mortality rates and decrease birthLrates when population densities are high and increase birth rates end reduce mortality rates when densities are low. The need for such processes is easy to understand. A population without limiting mechanisms would soon exceed the t-

.s_ . . _ _ _ . - . _ . __. _ _ . _ _ _ . _ . _ . . _ _ _ _. _ _ . _ . - _ _

1

-g I'

carrying capacityfof the environment and, likewise, any population which suddenly experiences a. slight increase in mortality rate would soon slide into extinction if not for some means of sus-taining the population at a new, but lower equilibrium density by an increased birth rate.

The question can be framed as follows: how far can the standing stock be reduced before the population could be threatened 'with er.tirpation or the population density is reduced to unacceptably low levels? In other words, how much predation-pressure can fish populations withstand? McFadden (1977) pre-sented-a summary of exploitation rates reported in the literature.

Exploitation rates equal to or greater than 25% of the exploitable age classes are. common. The range of exploitation rates of O._

Great' Lakes fisheries was from 7% to 40%. Unfortunately, none of the literature reports include exploitation of alewife popula-tions . -- Exploitation rates for closely-related species, American shad (Alosa sapidissima) and Atlantic herring (Clupea harengus) were 10 to 42% of the standing stock (McFadden, 1977). McFadden does not specifically say whether exploitation rates between 10 and 42%.are. ecologically _ damaging or not.

He-implies they.are not'when referring to his table from which the information included here was extracted. He states published estimates of annual exploi-tation rates greater than or equal to 25% of the exploitable year class are common'and that the figures in his table generally

represent situations in which substantial exploitation nas been

{]) underway a fairly long time.

Alewife standing stock estimates for Lake Michigan are c

- - - - . . . . _,.__,-.._,m -

, , , _ , . - - _ . . , - _ , . , , . . . ~ . . . , , . . . _ , , , _

,~,,-,c,.-__, - , , , ,

. - .- -- - - - - . - - - - - -.. - .. - = - . -

~

"~

O shown in Table 8 for 1973 through 1978. Table 9 shows the per-contage of the production foregone estimates and the commercial harvest to alewife standing stock for the corresponding years.

Production foregone during this 6-year period ranged from 0.35%

to 1.35% per year of the standing stock, while the commercial-harvest ranged from 13.08% to 34.25% per year of the standing stock. The combination of production foregone and the commercial harvest are well within the exploitation values cited by McFadden for American shad and Atlantic herring.

Further_ examination of Table 9 shows that the foregone production is a very small fraction of the Lake Michigan standing stock and that the foregone production is even a small fraction

)

of the commercial fish catch for all years betwen 1973 and 1976.

Table 10 is a similar analysis-- of the commercial harvest, fore-gone production, and total standing stock presented in Table 9, except-the foregone production estimates are those shown in Table 5.- It can be seen that foregone production-never-exceeded-0.3%

of the estimated alewife standing stock in Lake Michigan during 1973 through 1978.

As part of the evaluation of section 316(b) demonstra-

-tions, Truchan and Basch (1976) define " adverse environmental im-I:

pact" in part to occur when "the loss of organisms prevents l- maintenance of existing populations or communities" and "[t]here is a reduction of optimum sustained yield of sport and/or commer-(]) cial_ fish stocks". From the data presented in this section,

?

10:

Table 3 Estimated Alewife Biomass Available to Bottom Trawls in-Lake Michigan, 1973-1978 (Adapted from Hatch, 1979)

Biomass (x1000 lbs.)

Adult Expanded

• Young of Total

. Year Estimate Adult Estimate Year Alewives 1973 229320. 252252 8599 260851 1974 -184558 203080 68134 271215 1975 218074 239904 2932G 269230 1976 98784 108706 15876 124582 1977 89964 99004 15214 114219 Q 1978 153688 168903 31752 200655 Expanded to account for alewives at depths greater than the maximum -depths t2:awled, using a normal approximation technique.

.O

4 i

Table 9 Comparison of Foregone Production Estimates and Commercial Fishery Haz vest

• with Total Estimated Alewife Standing Stock in Lake Michigan for the Years 1973 Through 1978 Production Foregone Commercial Fishery Total

(% of total stand- Harvest (% of total () PF and CF of

-Year ing stock)- standing stock) standing stock) 1973 '0.55** 14.01 14.56 1974 0.61 16.78 17.39 1975 0.35 13.08 13.43 1976 1.35 31.47 32.82 1977 1.25** 34.25*** 35.50 1978 0.71** 19.49*** 20.20 Foregone production and commercial fish harvest data are from Rago (1978). Foregone production estimates were multiplied by-2.32 to approximate 2-unit operation at Cook Nuclear Plant.

The foregone production estima a used is an average of 1974 through 1976 (1,425,975 pounds of alewives).

a**

The commercial fish harvest value used is an average of the 1973 through 1976 catch (39,114,500 pounds).

l f-LO I

. ~. . - - . _ - . . . - . . . - . -

p. ( _ _-

Table 10 Comparison of Revised Foregone Production Estimates and Commercial Harvest

• with Standing Stock for Alewives in Lake Michigan, 1973 through 1978 Revised Production Commercial Fish Harvest Total Foregone (% of total (% of total standing (1 of PF and CF of Year standing stock) stock) standing stock) 1973 0.13** 14.01 14.14 1974 0.14 16.78 16.92 1975 0.10 13.08 13.18 1976 0.30 31.47 31.77 1977 0.30** 34.25*** 34.55 1978 0.17** 19.49*** 19.66 Foregone production estimates were multiplied by 2.32 to approxi-

-mate 2-unit operation. Commercial fish harvest data are from Rago (1978).

Foregone production value used is the average of 1974 through 1976 (340,168 pounds).

Commercial fish harvest value used is the average of 1973 through 1976 (39,114,500 pounds) ,

i I

l

there appears to be no support to a conclusion, based upon the state's definition (Truchan and Basch, 1976), that the Cook Nuclear Plant as having any adverse environmental impact on Lake Michigan.

O O

- - _ - - . . _ - . .. - _ . . . .. . - - . _ - , .. - _ ~- - - - .

A IV . . ALTERNATIVE COOLING WATER INTAKE STRUCTURE DESIGNS As a second. ground for initially rejecting the section 316(b) demonstration submitted by the Company, the MWRC Staff's letter.of tarch 30, 1979 alleged that the design and construc-tion employed in the intake structures at the Cook Nuclear Plant do not reflect the best technology since there are several al-ternatives.which have a " substantial likelihood" of reducing en-trainment losses. LT he Company was therefore directed to discuss alternative intake structures including, but not limited to, an offshore intake consisting of wedgewire cylindrical screena and modification of the existing intake through the installation of-fine mesh screens. ' Finally, the MWRC Staff dismissed out-of =

(k hand the alternative intake structu;es previously evaluated by the Company (see Cooling Water Report at 150-90), since the alternatives considered do not minimize losses of-larval fish and do'not include such recently developed' promising alternatives

~

as cylindrical.wedgewire screens. -

To the extent that the Company's earlier; work is char-acterized'as not evaluating alternatives that do minimize losses ofularval-fish or that were recently developed, the MWRC Staff is generally correct. However, such an observation, standing by itself, does not demonstrate that the existing cooling water.in-takes: fail to comply with section 316(b) of the Clean Water Act.

To the contrary, such an observation is a tacit admission by the-MWRC Staff that at the time the Cook Nuclear Planu cooling water intakes were designed (in the late 1960 's) , or at the time

62 -

O construction began on the intakes (during the summer of 1972),

or even as late as the date when the Cooling Water Report was submitted (on January 1, 1977), there existed no intake tech-nology for once through cooling systems capable of reducing larval entrainment. Such an admission is alone sufficient to demonstrate that the Cook Nuclear Plant intake structures re-flect the best technology available at the time of system de-sign for minimising adverse environmental impact. The company rejects any legal analysis of section 316(b) which reads that provision in a manner that requires the backfitting of recently developed technology (see pp. 11-14, supra).

Despite these strong legal misgivings as to the MWRC's authority to direct any such backfit*ing at the Cook Nuclear

)

Plant, the Company, as requested by the MWRC Staff, has recently completed an evaluation of alternative cooling water intake structure designs for the purpose of determining whether it is feasible to install any such alternative that is likely to reduce larval entrainment losses at the Cook Muclear Plant. That evalua-tion, as reported below, finds no feasible alternatives to the in-C take structures presently existing at the Plant and, therefore, confirms the Company's assessment that the present structures comply with section 316(b) of the Clean Water Act.

The evaluation conducted by the Company was in two stages. First, a screening study was conducted to review all

., possible modifications to the plant to determine which modifi-(]) cations were most plausible for use at the Cook Nuclear Plant.

Second, a detailed evaluation was made of the two alternatives I

determined to be most plausible.. The results of these efforts '

are reported below.

A. Screening Study of the four factors identified in section 316(b) --

i.e., location,-design, construction, and capacity -- the MWRC Staff's letter of March 30, 1979, faulted only the design and construction of the Cook Nuclear Plant's intake structures.

Nonetheless, the Company has again reviewed not only alternative intake structure dasigns, but also location and capacity con-siderations in determining whether there exists any feasible al-ternatives to the existing intake structures.

1. Location. Location of cooling water intece struc-

'tures may have a major impact on entrainment and Dmpingement

~

losses. Intake structures located in unique spawning, nursery, or feeding areas obviously will have a greater effect on fish communi-ties than intakes located away from areas important to fish.re-production and feeding. Therefore, biological data collected near the Cook Nuclear Plant has been examined to determine-if changing the present location of the intake structures would re-8/

duce environmental effects.~ That examination shows that 8/ -

1This analysis is limited to an evaluation of locating the intake structures further offshore than present, but in the same general vicinity as the Cook Nuclear Plant. There is no reason to believe that a relocation of-the intakes'to some al-ternative area e but at the same depth as - the present structures,

-would reduce entrainment rates. Indeed, field data from the 1972 study at Cook Nuclaar Plant indicates that more alewife larvae were collected at the offshore stations near Warren Dunes State

Park than at offshore stations in the vicinity of the Cook Nuclear Plant; these differences were statistically significant O. (Special Report No. 52, Jude, et al., 1975).

. . ~ , - . ~ . _ . - - . . .- . . - . - _ - - _ - - . - . . -- -

i locating the intake structures further offshore than present is likely to increase environmental effects. This is because ale-l wife larvae concentrations do not appear to decrease with greater {

depths, but macroinvertebrate concentrations are greater at in- I creased depths. Thus,-moving the Cook Nuclear Plant intake struc-

.tures offshore will not greatly reduce (if at all) alewife larvae entrainment rates, while such relocation is likely to signifi-cantly increase Mysis and Pontoporeia entrainment rates. The grounds for this conclusion are described below.

Distributions of fish larvae appear to be highly erratic and often inconsistently related to water depth. Larval concen-trations apparently change with time of day, season, year, and prevailing environmental conditions such as wave action, current, O.

and water temperature. Field data collected during July and

-August 1976 at cath the Cook Nuclear Plant and the J.H. Campbell Plant confirm these observations (see Tables 11-12 and Figures 3-7).

Tables 11 and 12 show the mean alewife larvae density offshore-from the-Cook Nuclear Plant for July and August, re-spectively. There appears to be a significant drop in alewife larval densities at the 21-meter station from the 6 , 9, 12 , 15-and 18-meter station during July (Table 11) . However, no alewife larvae were present at the 3-meter station and the 1- and 6-meter stations both had about 1000/1000m3 . Thus, sampling variability is a possible explanation for the low value at the 21-meter sta-tion.. Alewife densities during August (Table 12) drop from

[]J 146/1000m3 at the 1-meter station to 61/1000m3 at the 6-meter sta-tion. The stations from 9- to 21-meter depths had f airly uniform

O Table 11 Mean Alewife Larvae Concentratiens in number /1000m3 during July 1976 at Cook Nuclear Plant (Numbers in parentheses under " Station" are the number of samples comprising the mean. Data from the Great Lakes Re-search Division, University of Mich.)

Station Day Night Beach 1098 884 (3) 3m 0 -

(2)

O 6m 928 3059 (4) 9m 451 763 (5) 12m 2270 -

(5) 15m 639 -

(5) lam 432 -

(5) 21m 106 51 (4)

O

,kqJ

^--

+

Table 12 '

Mean' Alewife Concentrations in number /1000m3 during August 1976 at Cook Nuclear Plant . i (Numbers in parentheses are the number of ,

values in the means. Data from the Great Lakes Research Division, UniveJsity of Michigan)

Station Day Night Beach 146 225 01 3m' 87 80 (2) 6m 61 65 (4).

9m -19 342-

-(5) ,

12m- 22 381 (5) 15m. 34 146 (5) 18m 0 45 (5)

.21m 22 76 (4) '

i 67 -

N1 densities of 19 to 34/1000m , with the exception of no alewife 3

collected at the 18-meter station. Night collections had a l similar distribution from the shallow to the deep station as was found for tr-, day samples, except the densities were usually higher.

Field data collected near the J.H. Campbell Plant show alewife densities increase, decrease, or remain fairly constant from the shallow to deep stations depending upon sampling date (see - Figures 3-7) . Data collected June 17-23, 1977 (Figure 3) show more larvae were collected as station depth increased (Jude, et al. , 1978). On July 7-10 (Figure 4), the maximum ale-wife density occurred at the 3- and 9-meter stations.- Stations 12 133 21-meters had fewer alewife larvae, with densities decreasing slightly as station depth increased (Jude, et al. , 1978). Samples collected July 25-28 (Figure 5) were similar at all srstions from 6- to 21-meters, with variability between stations randomly dis-tributed. Alewife larvae dont' ties at night appeared to be higher offshore compared to near-shore samples. August 3.5-19 alewife larvae distribution was similar among the 3 , 6 , and 15-meter stations, which were higher than the 9 , 12 , 18 , and 21-meter stations (Figure 6). The 9 , 12 , 18 , and 21-meter stations had similar alewife larvae densities (Jude, et al., 1978). On September 21-23 (Fly,ure 7), alewife densities dect ased sharply from the 1.5- and 3-meter stations to the 6- and 9-meter stations.

No alewife larvae were collected at the 15- through 21-meter sta-tions during the day. v)

Contrary to the inconsistent fish larval data, field surveys of benthic organisms show a marked increase in concentra-m s- a m ---er- = w 4 ~ - -ye -te n % -

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Ilumber of alewife larvae per 1000 m for opcnwater Lake Michigan stations near the J.11. Campbell Plant, eastern Lake Michigan,17-23 June 1977. O = Day 13= tilght ilD = no data

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r mber o.~ alewife larvac per 1000 m for openwater Lake flichigan stations near the J. II. Campbe 1 Plant, eastern Lake Michigan, 7-10 July 1977. O = Day CI= flight f 110 = no data I

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O tion at greater depths. Estimates of Pontoporeia affinis and Mvsis relicta entrainment at Cook Nuclear Plant are 130 x 106 and 65 x 106 individuals per year, respectively (IMPC, 1977).

Pontoporeia are abundant during all seasons of the year and in 1

the four study zones near the Cook Nuclear Plant. Mysis become very abundant at depths greater than 24 meters. Figure 8 shows the densities of P. affinis at the Campbell Plant site versus water depth. Densities reach a maximum at the 15-meter station, then drop slightly and stabilize at the 20- and 25-meter stations (Jude, et al., 1978). -

Pontoporeia densities in the circulating water of the Cook Nuclear Plant are between 0.050 and 0.100/m3 (IMPC, 1977).

It is estimated that if the intakes were in 12 meters of water, O entrainment rates would be 1,000/m3 or more. Moving the intake structure to 15 meters probably would ror .t in entrainment rates of 1.75 to-3.50 Pontoporeia/m3 (Ayers, personal communica-

• ion).

. With respect to'entrainment of Mysis, it is estimated that moving the presa.nt intakes from the 7.3-meter isobath to the 14.6-meter isobath would increase Mysis entrainment by a factor of 10, and moving it to the 22-meter isobath would increase en-9/

trainment rates by 100 times the present rate.- Given that both 9/

~

Accurate density' estimates for inshore Mysis populations near the Cook Nuclear Plant have not been made. By combining the re-sults of several studies, a rough estimate of the probable Mysis

, densities ,at Cook Nuclear Plant can be obtained (Ayers, personal i

communication). Reynolds and DeGraeve (1972) determined daytime Mysis densities to be 717, 4857, 62682, and 96181 individual per

. rs year at depths of 27.4, 36.6, 45.8, and 54.9 meters, respectively.

This represents an average for the four stations (depths) of 41109 Mysis per year. ,At each station, 724 m2 of bottom were szmpled 2

or for four stations 2896 m . Dividing the mean number per four stations per year by the total area sampled gives 14.2 Mysis/m2 f l

i -- continued --

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(]) Pontoporcia and Mysis are important fish food organisms (Wells and Beeten, 1963; and Dryer, et al., 1965), such a relocation of the intake se.ructures is likely to increase adverse environmental effects. Therefore, an intake structure location change is not an effective means of reducing entrainment impacts at the Cook Nuclear Plant.

2. Capacity. Assum 7c Tg tre pro-

> I portional to the circulating w

{rs g..

Lity of operating the Cook Nuclear Pla 65 g easis flow JJ rate has been investigated as g y nont losses.

At the Cook Nuclear Plant this U

yf

$( emoving 4 x circulating water pumps from r j( yz erated o

with only two of the three ci:

3 uice and St O Unit 2 with two of the four a- N' would t

result in higher circulating " "

ser back-pressures resulting in decrea 4 s s 4' etermine

+ A whether such action was warra dl to com-D[

9/ -- continued --

year. There is reason, however, to believe that this estimate sub-stantially underestimates the actual Mysis concentrations in the lake.

Grossnickle and Morgan2 (1979) reported Mysis population mean density of 466 Mysis/m / year at the 30- and 50-m depths; this estimate is 33 times higher than Reynolds and DeGraeve. Since the best population estimates for Mysis are obtained from night sampling (Grossnickle and Morgan, 1979), as was done by Grosc-nickle and Morgan, it is necessary to correct the estimates made by Reynolds and DeGraeve. At the 9.1- and 18.3-meter depths, ,

Reynolds and DeGraeve (1972) reported annual catches cf 0 and 31 Mysis, respectively. Averaging these give. 15.5 Mysis/ year /2 stationst cultiplying by 33 to correct for daytime sampling gives 511.15/ year /2 stations; and dividing by 1448m 2 /2 stations gives an estimated mean density of 0.35 Mvsis/m / year near the Cook 2

(]) Nuclear Plant at the 12- to 15-meter depth contours. Thus, from the 9.1- through 45.8-mete'r stations, Mysis densities increase roughly at a logarithmic rate.

(]) pare the economic penalty arising from that mode of degraded plant operation with the likely reduction in larval entrainment.

The comparison shows that redtced pumping at the Cook Nuclear Plant cannot be justified, i In order to obtain realistic estimates of the amount of

.ated with decreased circulating water flow, 2T 4

6L ' Service Corporation's Performance and I

s' on performed the necessary calculations.

5 va

$ its of which are presented in Tabic 13, a

B # usign curves, the circulating water system L;7 'oh 4

2 enser design data, condenser performance l

2 j$,

em fq o

salance information. It is apparent from

$d mo ough the purps are rated 230,000 gpm at O'

noving a pump from service does not de-9

" d ig water flow by that amount. This is due s k

+

f

~

jvice pumps operating at a different point d$ ;o decreased system resistance. However, s4

$ !p from service results in calculated AT's ~

which violate NRC Environmental Technical Specification 2.1.1.2 This Specification ca.11s for a condenser aT not exceeding 22'r i l'F for Unit 1 and 17'F i l'F for Unit 2, except during deicing or pump malfunction.

It is for this reason that it never has been plant practice to remove circulating water pumps from ser-vice during any time of the year.

At lower inlet water temperatures, generation curtail-ment from full load would be less than that shown on Table 13.

(

llowever, for present purposes the Table 13 estimates are appropri-

_. _ . . ._. _. , _ _ . . ~ . . . . _ , _ - . _ _. _.

p ,- , . .

\

Table 13 Effect of Reduced Circulating Water Flcu at 70*F Inlet Terp2rature on Unit AT, Cordenser Backpressure, ard Electrical Ceneration

• Reduction * *I)2 crease frrri frcn Design Condenser full load in '

Ib. of Cire. Water Flow Rate Flow Rate Bach tessure Electrical 4 Unit i Pmps in Service (x103 cm) (%) AT(F') ("n $) Output (N)

E 1 3 710 Base 20.7 2.35 Dase 1 2 570 8.7 25.8 2.75 4.8 2 4 903 Base 16.6 1.96 Base 2 3 790 7.0 19.0 2.16 6.6 2 2 613 18.0 24.5 2.63 24.1

'Ibe redoction from design flow rate is calculated on the basis of a mximra flow rate of 1,613,000 gpa with all seven circulattrg water prps in service.

• • The decrease in electrical output colirn considers a 2 sti credit per idled prp for reh3 atixiliary power regairenents.

() ate since they give an insight into the approximate economic penalties associated with circulating water flow rate reductions during the biologically important warm water periods (the poten- .

tial spawning period tahon to be April 1 - September 30). As is evident from Table 13, the decreased unit capabilities resulting i

from reduced circulating water flow rates are significant. On an l

averago basis, a loss of 4.8 mw on Unit 1 and 24,1 mw on Unit 2  !

represents lost realization to the AEP System of $5,120 per day. '

The alternate to accepting $5,120 por day of lost generation would be to-replace it with coal-fired-generation if available. ,

Coal-fired generation would result in higher fuel costs since i

-higher cost coal' units would be required to replace the nuclear '

-generation. Using May 1979 actual AEP fuel costs, the increase t would amount to about $5,660 per day. Most of this increased fuel cost would be passed along to the consumer in the fuel adjustment clause.

Extrapolating'these figures to a future biologically important warm watcr period of April 1 through September 30, an analysis of annual costs is possible. It is estimated from ex-perience that during the warm water period there would be a 53-day refueling outage of Unit 1 and Unit 2 would not be out of service for refueling. Using a historical availability of 0.935 and assuming that the plant would operate at base load when on-line, operation with two circulating water pumps on Unit 1 and .

two pumps on Unit 2 would result in 112,960 mwh of lost genera-tion. Such an annual loss would amount to about S833,600 using 4O

-the 1978 AEP average not realization figure of 7.38 mils per kwh.

i 1

I

() If-the lost generation was not accepted and the load replaced with coal-fired generation, then the AEP System, and ultimately  ;

the consumer, would realize increased fuel costs. The net in-creased fuel costs would amount to about 8.16 mils per kwh, or approximately $921,800 for the replacement generation during the 10/

April-1 through September 30 time period.~- ,

In comparison to these substantial costs, the reduc-tion in larval entrainment from reduced pumping at the Cook

-Nuclear Plant is not cost justified. Operating both Units 1 and

2- with -two circ 21ating water pumps each would result in a 26.7%

reduction-in flow rate (see Table 13). Assuming that larval on-l trainment is proportional to flow rate, such plant action would 11/

result-in an entrainment reduction of about 26.7%.--

Using the i

() Company's revised entrainment production foregone astimate of 165,722 kg of lost salmonid production per year (see Table 5 and pp. 47449, supra), and the MWRC Staff's dollar conversion algo- '

rithm which values that lost production at $541,660 to sport 12/

fishermen, a 26.7% reduction in entrainment is worth only $144,623.

10/

It should be made clear that the lost realization cost (S833,600/ year) and the not increased fuel cost ($921,800/ year) are-independent of each other and should not be summed to obtain a total cost.- '

11/

~~

This calculation assumes that entrainment and flow rate-are

-proportional.

12/

~~

And, even if-the MNRC Staff's figure of $2,242,374 for lost salmonid production is used, the value associated with reduced

n. pumping would be. 5598,715._ This is still substantially below 3-U_ the cost:to the Company and its consumers associated with re-duced pumping.

_ . ~ _ _ _ _ . _ _ _ . . _ . ~ . _ _ . _ . _ ~ . . . _ . _ . _ _ _ _ . . . _ . _ . _ _ _ . _ _ _ _ _ _ _ _ . . _ _

._ _.._-_________.___..._..-_______._m ._._..

l i

Yet, to achieve this entrainment reduction, the Company's con-sumers would be forced to bear increased electrical costs of between S833,600 and $921,000 por year. Certainly, there can be no cost justification for requiring the Company to take such action.

3. Design and construction. There are many papers written on the state of the art of intake design (Marcy and Dahlberg, 1978; USEPA, 1976; 'Hanson, et al., 1977; Richards, 1977; Sharma, 1978). Table 14 provides a listing of all intakes that are discussed in the scientific literature, both practical and experimental The applicability of these designs to the Cook Nuclear Plant has been considered by the Company. Discussed below are the various alternatives easily rejected during the

.O screening study. The two most plausible alternatives, and those mentioned by the MWRC Staff, are the fine mesh cylindrical wedge-wire screen and the fine mesh traveling screen. These two al-tornatives are evaluated in more detail in parts B and C of this section.

(a) Stationary Screens The stacionary type screen would be impractical due .to debris removal problems. This type screen is used in areas where ,

debris is not a. problem, and therefore is not feasible at the Cook Nuclear Plant (compare pp. 22-23, supra).

(b) Perforated Pipes y Perforated pipe intakes have not been fabricated with

i-5 4

j TABLE 14 D

l Come(MT STAitG W tiv8CES AFID IECIS*!T.D TO Ht. DUCE 8tP!!cittf4T Afeo

, LNTAAeW AT LANCE PIAfH f1#4TS ' ,

t 1 i i'

Acoust Enter Peersecatte G e t Fes. Sawc fos. Sawc tan m E er Fesa sare

~

Paavent to evenss er C4ever ame Eta  !

Cootews Srsern f a si Daract ** Cet:ccie= ane Acumst Staus

! Parsecat Scacets

++

vantecat.'reavstems stect** + - + + (wes., rent m sm)

< ve secat raavete=s scact=s .

wefa F6see LeFfs ** ++ - ** * (we um # emt au ss[r t tsareemaar scattas ++ + - - -

l Psorsmarte cerc ensa.Es ++ - - - -

[

5enste turne-eemste cast scastas ++ ++ - ++ ++ (wer. ae=< m s.) }

}' Jo.ma ses watt star tas ++ + - * ++ ( srea st seats es.sv) r e.c asa naarna - ++ + + + . * (s-,a tt sc ata e.s e ) '

onwn scatens ** + - + -

f Horatsms eesc scattas ++ + - + -  !

one. scrie-a usuas ++ + - + -

In asw mate s - + - + - -

i itacen retwee ecos ++ ++ - - ++  :

t i Utseaweemat SamasEms 3 3

L e cesis + - + - - t r

.- Sowe.o + - '+ - - .e.n j vreecer, sannec=s- ,

l Warta stus + - + - -

Lovetas ** - ++ - -

l~

Vee.ecare caps ++ - - - -

1 Uwe tc =cottes ++ - + - -  !

i t

Ettcamac scattats + - + - -

[ (ast( sett (Maam sch((N. -

- + = - k

i. D e wc a s e cee/Rc he= a e, i

l naaeroavat was <t ems sc.cr.s ++. ++ ++ - + (we,. .s.t ) ,

( luetense etant. scatens *+ ++ - ++ -

i j f e t es=w s . ++ ++ - ++ - (e rtsst.) [

l' e rres emovoenc *e terr susrces . ++ (roacmar ents) ++ *e ** -

or-t.e aremoscat s  !

I unuent west autanes ++' ++ - - ++ i e....s os.c e.rancs + + - -

+ ( . arce) ,

1 i

i

• Net areLec46tc

+ P ssene.c em caeces,waras a*etscareen l

j ++ Paeve n meetecareen l' (resee tia <v ame 0.ntaans, tf.4) i

i O fine mesh perforations. The availability of wedgewire screens makes the similar, perforated pipe intake undesirable. A perfor-ated pipe intake would not afford any advantage ovur a wedgowire intake.

(c) Drum Screens, Rotating Disc Screens, llorizontal '

Traveling Screens and inclined Plane Screens  ;

These screens are not considered feasible because they would not offer any advantage over fine. mesh traveling screer.s.

Horizontal traveling screens and inclined plane screens are both in the experimental stage. Drum screens and rotating disc screens have not been used-to filter large quantities of water.

None of these designs has been used with fine mesh for large capacity systems.  ;

(d) Filtration Type Intakes Filtration type intakes such as rapid filter bedb, radial well-intakes, and porous dike intakes would not be of

!  : sufficient capacity and still remain of a practical size-for l

l the Cook !!uclear Plant. A porous dike intake would require a fill small enough to prevent ichthyoplankton entrainment and l-l still maintain a low enough velocity to prevent icnthyoplankton L-l impingement on tha fill material. This structure also would have i to be able to survive both ice and wave attack.

(c) Trash Racks Trash racks would not protect ichthyoplankton because i of the coarse mesh and-heavy construction.

{])  :

u,,;,.__-,__.,_._.__-_._- _ _ - _________ _ ...__.. _ _.- _ - - _ . - - . . _ . _ . . _ .

p 83 .

() (f)- Bahavioral Barriers As shown in Table 14, behavioral barriers would not pro-tect ichthyoplankton and would not provide any advantage to the existing intake. These barriers were therefore not considered viable.

B. Cylindrical Wedgewire Screens In response to the MWRC Staff request that the Company consider the installation of cylindrical wedgewire screens as a means of reducing larval entrainment, the Company has developed a conceptual design for use at the Cook Nuclear Plant. This de-cign is based on the use of a screening material manufactured by the Johnson Division of UOP, Inc. The so-called Johnson screen

(]) is constructed of wire, with a wedge or "V" shaped profile, that is helically wound on support rods. The slot formed between the wound-wedgewire is inward-enlarging. This "V" shaped slot creates a nozzle effect during backwashing that enhances the cleaning pro-cess. When water is flowing in the normal direction into the _

mesh, the shape of the slot minimizes screen plugging. The screen-ing matarial can be fabriacted with slot sizes ranging from 0.010 inch (0.25.mm) and larger, in increments of 0.002 inch (0.051 mm),

and in any configuration from pipes to flat plates (Johnson, 1977).

i L 1. Existing wedgewire screen installationg. The American-l Electric FC',,et System has substantial experience in twe.use of ,

wedgewire screens for river wator makeup systems. Johnson wedge-i wire _ screens have been used for that purpose at the Big Sandy Plant (18.6 mgd) since 1963. Similar, perterated pipe intakes p have'ceen used at the Mitchell Plant (25 mgd) and at the John E. ,

L _ , . _ . . _ _

- 84 +

1 O Amos e1ane, unies 1 end 2 n3.3 mgd>. Atr currene1y is insta11-ing Johnson wedgewiro screens in the river water makeup structure at Mountaineer Plant (21.7 mgd), and plans to install those screens at the plent to be constructed in Rockport, Indiana (42.5 mgd). There thus can be no doubt as to AEP's commitment to wedgewire scroon technology whero its use is both appropriato and feasible.

AEP's most recent dasign concept for installation of wadgewire scroons is being used at the Mountaineer Plant, av J also will be used at the-Rockporu Plant. This design consists.

of 36-inch diamator pipes which run from the . shoreline porpon-dicular into tho 0hio River. At the river end of this pipo, a "Y" junction is used to connect two Johnson Scroon sections 1ay-O. ing parallel to the shore line onto ecch branch of the "Y" junc-tion. ' This resuits in s structure whero each pipo from the shoreline has four 4.5-feet long, 48" inch diameter Johnson ole-ments attached. A typical wedgewire screen olement is illustrated

~

in Figuro 9. The pipes are supported abovs tho' bottom to avoid benthic organisms'and well below the aurface to avoid inter-l ference to navigation. Tho 1/2-inch by 7/8-inch mesh will have a velocity of'less than 0.5 fps during maximum anticipated-coinci-l- _ dental. flow.

An air bachwash system must'be' installed in order to free the screen' elements of debris. This systen, will consist cf a single air accumulator tank, located on short, a spray pipe

' located inside each scraen, and tho interconnecting piping

.'O:

-and valves. The system-operates by pressurizing the accumulator l

L.

w srs-w-w,-*emLw.-.r<w--=--mv--v-**---=w -*"*---e-* ate-* +*-*-**'Mv-- *-8-*r~'<r'--*-P ""'P-"'*T'* *******"*"W"T" - ""7T~ "#

l I i /

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1 i O >

t e

B i

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+

86 -

() tank, then opening a valve to allow air to travel to the spray pipo located within the scroon, thus backwashing the acroon.

While this intaka design is sufficient for river water makeup systems used by plants with closed cyclo cooling, thu flows that can be accommodated are orders of magnitudo smaller than the flows required at the Cook Nuclear Plant (approximately 2000 mgd). For a number of reasons the design concepts used at the ri,ver water makeup systems cannot simply bo " scaled-up" to the larger needs-of the Cook Nuclear Plant, nor can the experience gained at these river _ plants be directly transferred to the prosent situation.

First, the wedgewire screen systems used in a riverino situation have boon designed to take advantage of the relatively

(])

high- river flow past the structure (normally 1.5 fps and faster) to act as.an offective bypass current. At the Cook Nuclear Plant intake' structures the lake currents are loss than 0.5 fps more

~

than 50% of the time (IMPC, 1975). This may not be a sufficient bypass current to carry ichthyoplankton past the very large array of wedgewiro screens proposed for the Cook Nuclear Plant.

Second, those rivorino intakes are below the photic zone and, as a result, do not have any biofouling problems. The potential for_biofouling of the wedgewire scroons exists at the Cook Nuclear Plant because-of_the clarity of the lake water. The present intake structures act as a substrate for Cladophora, which grows in lengths up to six inches (John Dorr, Great Lakes

, () Roscarch Division, pers. comm.). It is not known for sure if the

i i

() long Cladophora strands would.causo a serious biofouling problem I on 1-mm-screening mosh.

Third, the rivers on which the prosent wodgewiro scroon i design is unod do not have any ico floa problems. This is in +

c distinct contrast r.o the Cook Nuclear Plant situation (soo pp. 20-22,  ;

supra).- If the rivers de froozo, the ice stays at the surfaco  :

(

and'does not' form the ico ridges that can strika bottom, as on  ;

Lake Michigan. Moroover, frazil ice does not pose a proolem for i

the prosent design due to the largo mosh opening. Further study l of the frazil ico phenomenon, especially in the context of 1-mm mesh openings, would be required prior to installation at the

• Cook Nucioar Plant.

i Fourth, the present design utilizes upstream dolphins O to divert any largo dobris that may damage the wedgewire scroons.  ;

The intako design that might be used at the Cook Nucioar Plant I would need to be able to survivo-the significant quantity of  :

debris borno by the lake (comparo pp. 22-23 , ag ra).

For those reasons the company-presently has no assur-ancos that a wedgewiro_scroon system of sufficient sizo and ro-liability to handle-tha Cook Nucioar Plant needs coulo-be-do-signed. Nor do the experiences of other ut111tios with such scrooning material provide the nooded confidence. Design work '

and testing is being done with fine mosh wodgowiro scroons at numerous power plants. Tho Company's review of this work indi--

catos that successful application to large-scale, once-through ,

c cooling systems has not yet been demonstrated.

)-

The Consumers Power Company is proposing to use a 3/8-inch (9.5 mm) wedgewire screen at the intake to Unit 3 of its Campbell Plant (532.8 mgd). Tests have been performed this past summer using various mesh opening si:e down to 2 mm; the results of those tests have not yet been reported. The Company under-stands that the purpore of these pumping tests is to determine whether a mesh size smaller than 9.5 mm is both feasible for installation and advantageous in reducing larval entrainment.

The Leepbell Plant intake is so designed that, if clogging cccurs from either debris or frazil ice, bypasses will open and raw lake water would be utill:ed.

Other plants currently under design will make use of various wedgewire screen configurations: (a) the Carroll County Station (172.8 mgd) on the Mississippi River is being designed to utilize 1-mm mesh opendags; (b) the Marble Hill Plant on the Ohio River is being designed with 1/4-inch (6.4 mm) openings; and (c) the Edgewater Unit 5 will utilize a screened velocity cap with panels that hinge-in under clogging conditions to allow adequate water flow.

In addition to these efforts, studies on wedgewire screens have been conducted by Delmarva Power and Light (Hanson, et al., 1978A; Hanson, et al., 1978B). Both biological and engineering studies were conducted with various mesh sizes ranging l

from 0.25 mm to 1.0 mm and with various shaped screens. Pumping t

l

! studies also were conducted to ascertain debris fouling and biofouling limits (see also pp. 98 & 100, infra).

g]g l

_ 69 _

O Notwithstanding the scope of this work, and the operat-ing experience with wedgewire screens both within and outside the AEP System, there han been no intake designed or operated to date that approximates flows and conditions like those at the Cook Nuclear Plant. Indeed, the Company's review indicates technology would have to be developed that would allow reasonable assurances that this proposed alternative intake structure would be cost effective and sufficiently rugged to survive in Lake Michigan.

The Company is not alone in these conclusions commentators also agree that fine mesh wadgewire screen intakes are experimental.

Sharma (1976) states as follows:

These systems have been used at locations requir-ing small amounts of water comparable to make-up

(]) water demands. How these systems can be enlarged to provide flow and retain biological effectiveness for a once through cooling syster is yet to be demonstrated.

And, Richards (1978), in the same symposium, was of the view that:

First, the perforated-pice intake has practical size limits and has not been considered adequate for handling the large quantities of water re-quired for once through cooling systems. * *

• Second, there are legitimate questions of relia-bility, as far as clogging and maintenance are concerned.

The small-opening wedgewire or round-hole con-cept for reduction of entrainment is still in ,

the experimental stage.

O

l l

1 l

O Perforated-pipe intakes are not the solution for all water intake problems.

We hear the term "best available technology" beit.g applied to such a screen, but we must recog-nize that this may or may not be so, depending on many site-specific and capacity considerations.

Despite the misgivings over the application of fine mesh wedgewire screens to the Cook Nuclear Plant situation, the Company has gone ahead and developed a preliminary design concept for evaluation purposes. The results of this effort are described next.

2. Conceptual design for installation of cylindrica2

(]) wedgewire screens at the Cook Nuclear Plant. A preliminary lay-out for a Johnson wedgewire screen intake system has been de-veloped to determine the feasibility for implementing such a system at the Cook Nuclear Plant. This layout is based on the manufacturer's input $ In order to reduce costs, it has been a design objective to retain as much of the existing intake struc-tures as possible. To this end, the preliminary design contem-plates extending each of the existing three intake pipes an addi-tional 1,150 feet. At the end of each of the extended pipes, a series of seven feeder pipes would be arranged in a "Y-shaped" fashion. Johnson wedgewire screen elements, six feet in diameter, would be attached perpendicular to the feeder pipes; there would be ten such screen elements per feeder pipe. The entire intake structure would require 210 screen elements. The layout is

r O. depicted in Figure 10. Additional detail of the support system l and screen assembly is shown in Figures 11 and 12.

On the basis of this design preliminary cost estimates have been developed. An intake system which would utilize John-son screens would essentially entail an installation procedure  !

equivalent to that followed in constructing the present intake system. Approximately 3,450 feet of 16'-0" diameter corrugated pipe would-havo to be installed in extending the existing intake

-pipes. The Johnson screen alternative also would utill:e a network of feeder pipes, in this case, an estimated twenty- ,

one 3'-0" diameter feeder lines totaling 3,500 feet in length.

This work, as in the' original pipeline installation, woulc necessitae.e_ diving operations and dredging from barges. The O estimate of the cost to install this eystem at the Cook Nuclear Plant is based on contractor quoter for the scope of work de- :i picted in the proliminary layouts (see Figures 10 through 12) . I The scope of work would include the cost of the 210 Johnson screen elevents; contractor mobill:ation and demobiliza-tions installation of approximately 7,0$0 feet of pipe the  ;

placement of sand,. filter cloth and riprap over all sections of pipes demolition of. existing cribs and 'he 16'-0" diameter pipe  ;

elbaw; the' connection of the 210 Johnson screene to a 36" dia-meter flange; installation of the screen support cystem; and the 13/

I construction of a safe harbor.'" The manufacturer's price quote i

13/

~~ . .

Safe harbor construction is suggested since its existcace would vEn- keep construction time to a minimun, eliminate a large portion of U " downtime", provide an Onmediate means of safety during storm, and ,

provide a materials delivery and handling site, i

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O Figuro 11 ,

WEDGE-WlRE SCREEN SUPPORT SYSTEM (TYR)

ANGLE IRON STRUTS - ASSUME (3)

, BOLT CONN.TO SCREEN EACH .

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' PRE-CAST CONC. 0 LOCK 6'-O" DIA. INTAKE SCREEN 6'X 4'X 3 {

ANGLE IRON EMBEO.IN

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ASSUME (3) BOLT

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ly

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O rigure 12 WEDGE-WIRE SCREEN ASSEMBLY 17'* O' _

7 0' DIA. INTAK7.

C 1 J SCREEN

--.L LAKE OTM [ LEV EXT END RIP H AP 0'- 0" E A. 06AXN OF PIPE ,

3 -

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(' 3' S0#- 200 # I w-- - ,a ._

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i for 210 wedgewiro screens is $12,000,000. The estimated con-struction cost for insta11ating this system is $23,250,000. This is based on 1979 wage rates, fuel, and material costs as of July 1979, and is-subject to increases due to inflation. The expected i increases may be on the order of lot to 12% for each of the three seasons during which this work will be performed. The estimated ,

total cost, including normal allowancos for engincoring, adminis-trative and othor costa, as well as a 10% contingency allowance, is $44,592,000. This figure is in 19',s dollars and does not I

include allowances for the cost of capital or inflation.

i Based on the time frame of the original intake instal-lation, it is estimated that installation of the wedgewire scroon alternative would have a duration of three seasons. Each season is defined as the period of May 1 through October 1. The actual impact to the Cook Nuclear Plant operations, however, depends on ,

the time it takes for tie-in of the new system to _the original pipelina since almost_all sections of the new pipolino can be installed without affecting present operating procedures. It is probable that only one unit would be operating during " tie-in".  ;

The_ estimated time for a " tie-in" is approximately two and one-half weeks por intake.

The costs associated with this downtime, as well as those associated with an ice protection and air backwash system, are not included in the $44.6 million estimate given above.

These cost _are likely to be-significant and require further study and evaluation. In addition, there-are a number of un-

(() l resolved technical issues that must be considered before instal-

_._ _ _ _ . _ _._ ._ _ _ ._._ _ _ ._._. _ ., _ _._..___ . . _ - . _ - . ~ . _ _ _ _ _ . _ . _ . . _ . - .

r i

() lation of-the-Johnson wedgewire screen system. These are sum-l mari:od below.

First, the wedgewire screen manufacturer has recom-mended that the proposed intake be located in a water depth of about 35 feet, as opposed to the 20-foot water depth of the current velocity cap intake structure. This recommendation is based on the severe icing conditions which often occur on the eastern shore of Lake Michigan. It is the manufacturer's opinion

.that a 7rea water depth is required to increase the reliability.

of this intake system. However, in order to 1scate the new intakes in about 35 feet of water, the existing tunnels would have to be extended to approximately-4000 feet offshore. Calcu-lations show that this is not possible since the drawdown (eleva-O- tion difference between lake level and forebay level caused by friction losses in the tunnels) resulting'from this tunnel length would allow only marginal circulating water pump submergence.

Calculations do indicate.that the wedgewire intake structures could be located in approximately 30 feet of. water.

It. is not clear that locating the screens at this depth vill l protect them from ice floes. Past. experience with the existing intake system has shown that severe ice damage can be expected (see pp. 20-22, supra). It seems unlikely that a wedgewire screen' intake system could be protected sufficiently to allow it to survive in this lake environment.

Second, the deicing system which is presently Leing 3 utill:ed at the Cook Nuclear Plant would be totally ineffective

{]J  ;

to prevent fra:11 ice formation on a wedgewire intake system.

. .._ _ .._. _ ___ .-. _ . _._.-~ _.. _.-- __. -- _._ .- ~ _.

() This is primarily dae to the large area covered by the wedgewire intake screens. The detailed deaign of such a deicing system would require extensive model studies that presently cannot be cost justified.

Third, there is no assurance that the wedgewire screens 0

can be adequately cleaned through a backwash system. Based on existing technology, the most effective method of b iva hing the wedgewire screens would appear to be some *c. of cu.1.ressed air system. This type of installation has been successfully used within the AEP System. Such use, however, has been limited to makeup water systems with maximum intake flow rates of approxi-mately 60,000 gpm. Extrapolation of the existing design to the Cock Nuclear Plant would indicate that a single air pipe could be used to backwash two screening eierents. Thus, the backwash system would require sn accumulator tank, 105 motor operated inch valves and approximately 400,000 feet of 4-inch pip There are no assurances that a system of such size could be reliabily s

operated to assure continuous cleaning of the wedgewire screens.

In addition, if the screening elements must be backwashed once every four minutes (see pp . 104-06, infra), a very large compressed air system would be necessary. Moreover, extensive model testing would be required to evaluate the effectiveness of such a back-washing system.

The ability to backwash the wedscaire scraens is essen-tial, since the likelihood of both biological and detrital foul-ing at the Cook Nuclear Plant does exist. Vigander (1998) states that plugging is caused by two factors: biological fouling and detrital fouling. Fouling studies of wedgewire screens have been

performed in the lab (Hanson, et al., 1978), in a brackish water canal (Miller, et al., 1978), and in a riveris.e-like environment (Vigander,-1978). All- tests were conducted with a minimum slot opening of 1 mm. Cleaning schemes varied from manual scrubbing and high pressure water blasts on land to reverse pumping and air / water backwashing.

Results varied based on the environs of the screen.

The lab work appeared to be the least satisfactory due to the use ,

of very high concentrations of detritus. Miller, et al. (1978) found that biofouling was a much more serious problem than detrital plugging. The hydroid, Garveia franciscans was the predominant agent of biofouling. The hydroid tangled and acted as a net to accumulate debris. There is the potential for a O sim'isr situation at the Cook Nuclear Plant. The Cladophora which-covers the present intake would be able to bridge the 1.0 mm mesh _and act as a further trap for detritus.

Miller, et al. (1978) had to remove the screening ele-ments and_ mechanically clean them approximately once very three weeks even though the screens were being backwashed. This was not a major task because of the small size of the test element and because the test facility was easily accessible. This would not be the case-for a greater number of larger elements offshore in Lake Michigan. The screen-elements would be inaccessible in i the winter months when ice would prevent access.

Vigander (1978) found that air / water backwashing worked; however, no quantitative results are given. Typical results re-

}

ported appear that the screens operated for approximately six hours before a pressure differential of 1.25 meters of water re-

. _. .. . ~ _ . - - .- . . _ - - . - _ - - - . - - . . - . _ . . . -

( suited. Backwashing brought the head differential ~back down, Vigander noted that debris consisted of silt and fragmented aquat/c vegetation. No biofouling was reported.

Since the fouling problem cannot be predicted from the conflicting results of others, an in situ program of study would be required. The current situation at the Cook Nuclear Plant indicates that both biofouling and detrital fouling may cause major problems.

In view of these-uncertainties, it is the opinion of the company that the reliability of a cylindrical wedgewire screen intake would be marginal at best, and that other pro-visions would have to be made to ensure a reliable source of ,

water to-the essential. service water system which is the ultimate O heat sink for reactor cooling.

3 Biological effectiveness of a cylindrical-wedgewire screen intake. In order to fully evaluate the benefits involved in replacing the existing intake with the Johnson screen alterna-tive, a comparison must be made between the-present ichthyoplankton mortality rates and those to be expected with fine mesh wedgewire L screens. As stated-earlier, a 100% mortality was assumed in l

I making estimates for the Cook Nucler- Plant entrainment mortality.

This was a conservative assumption that may be too conservative-based on the present literature. A more realistic estimate may be that closer to 50% of the entrained ichthyoplankton are killed by plant. passage (Ecological Analysts, 1979). In trying to

() project .aortality caused by fine mesh wedgewire screens, two

-100 -

If factors, mesh size and impingement duration, must be considered.

Work has been done as to the percentage of ichthyoplank-ton retained by various sized meshes lFisher, et al., 1976; Tooljanovich, et al., 1978; Hanson, et al., 1978A; Hanson, et al., 1978B). One of the objectives of this work, as stated by Tomljanovich, et al. (1978), was "to determine the largest screen opening that would retain a high percentage of larval fish (a few days to a few weeks in age) *** ." When mesh sizes go above 0.5' mm the number of fish retained is directly dependent on the body depth (measurement from dorsal to ventral surfaces) and not total or fork length of the larvae. A detailed description of percentage retained versus mesh size is provided by Tomljanovich, et al.

14/

(1978):~~

The 2.5-mm screen showed average retentions ranging from 30.6 to 72.7% for larger species, whose average body depth ranged from 2.9 to 3.3 mm (Table (15]). For the screen with openings of

1. 8 1mn, average-retention ranged from 38.2 to 99.2% fo.- largemouth bass (average body depth 2.2 mm) and caannel catfish (average body depth 3.3 mm) , respectively (Table. [15]) . Average reten-tion for-the 1.3-mm screen ranged from 11.0% for

" 14/

~~

Earlier work oy Fisher, et al. (1976) _ indicated that mesh with square openings of 0.132 inch (3.35.mm) would rctain 100% of the

-larval tested._ It is important to note that this measurement was the diagonal measurement of the mesh and the mesh size is actually

.0.093 inch (2.4 mm). The species tested were king salmon (Oncorhynchus tshawytscha) , American shad (Alosa sapidissima) and-striped bass (Morone saxatilis), with fork lengtha of 32-50 mm for king salmon; 22-44 mm for Ameri can shad; and 17.6-37.6 mm for striped bass. Comparisons between the work of Fisher anu Tomljanovich are_ difficult due to the differences in the way that the data was developed. It appears that Tomljanovich considered early larval ~ stages, whereas Fisher used these sizes available' to

. ()

I him in the wild. The larger optimal mesh si=e, reported by Fisher appears to be the result of the large larvae used in his work.

sb-O OL O Table 15

- Percent Retention of f ist. on fine Hesle St e ecos' Weiglised H.en Slie (sma) 5,py, g,sh 95% Confidence of All 8.ntrained and Screen Opening theidner Average 1 ' ~ . , t ! aim s.

Jupi,qued Test Hsh Species (men) of lests Relained l en<er ' Upper l er.9th Width h ptte l Jewelfisti cichlid 1.0 5 100.0 100.0 100.0 7.2 1.5 l.8 1.3 6 6 11 . 1 58.7 7b.8 7.3 1.6 1 . 11 threadfin shad 0.5 19 100.0 100.0 10P.0 39.5 4.2 8.9 (Juvenile) 2.5 18 100.0 100.0 90.0 31.9 3.6 11 . 2 Golden shiner /- 1.0 12 97.0 93.2 99.3 11.7 1.5 8.8 f athead seinnow l.3 12 65.0 50.3 78.2 11.8 1.5 1.7 White sucker 0.5 12 99.9 99.8 100.0 14. 1.2 1.4 1.0 36 79.5 71.3 86.4 13.0 1.2 1.4 1.3 19 30.6 16.3 47.2 13.6 1.3 1.4 l Channel catfish 1.3 I. 100.0 - -

14.8 2.0 2.8 e '

1 . 11 24 99.2 97.1 99.9 15.7 3.0 2.8 O

'2.5 45 66.3 51.6 79.5 17.7 3. 4 ' 3.3 8

Striped bass 0.5 102 99.1 9t!. 7 99.4 6.2 0.7 1.0 1.0 66 29.3 24.1 31.9 6.6 0.9 1.0 1.3 14 24.0 8.0 4 4 . 11 7.7 1.0 1.3 liluegill 1.3 1 100.0 - -

1 3 . 11 2.0 2.9 1.8 13 99.4 97.6 100.0 14.3 2.2 3.0 2.5 16 -72.7 5 11 . 5 11 4 .,9 14.3 2.1 2.9

$mallanuth bass 1.3 12 99.9 99.6 100.0 10.0 2.0 2.5 1.8 24 82.4 66.4 94.0 12.0 2.1 2.7 2.5 9 30.6 9.2 51.8 13.4 2.3 2.9 targescuth bass 0.5 11 99.5 90.5 100.0 6.8 l.1 1.4 1.0 26 11 4 . 7 78.8 94.2 7.7 1.3 1.6 1.3 '19 11 0 . 4 11.1 Ud.2 11 . 9 1.6 1.9 r 1.0 9 33.2 17.6 61.4 10.3 1.7 2.2 ,

Walleye' O.5 12 99.7 94.6 100.0 5.6 1.1 1.4 1.0 18 0't. 7 11 4 . 5 94.0 9 . 11 1.3 1.5 1.3 16 11.0 8.2 14.3 10.3 1.3 1.6

' Current velocities (0.5-1.5 fps; 15.2-46.1 oa/s) and test dura tions (0.5-16.0 imin) were (ondeined for each species and scseen opening.

7

- 102 -

walleye (average body depth 1.6 mm) to

~

greater than 90% for three species:

smallmouth bass (average body depth 2.4 mm), bluegill (averago body depth 2.9 mm), and channel catfish (average body depth 2.8 mm) (Table [15]). For the 1.0-mm screen, average retention ranged from 29.3% for the smallest species, striped bass-(average body depth 1.0 mm), to 90% or greater for three species:

walle3e (average body depth 1.5 mm) ,

mixed minnows (average body depth 1.8 mm), and jewelfish cichlids (average-body depth 1.8 mm). This screen would have been expected to retain 100 percent of the larger species, including small-mouth bass, bluegill, and channel catfish.

Average retention for the 0.5-mm screen was greater than 99% for the four species with the smallest average body depths:

walleye (average body de,3th 1.4 mm),

largemouth basr. (average body depth 1.4 mm), white sucker (average body depth 1.4 mm), and striped bass (average body depth 1. 0 mm) . A screen opening of 0.5

() mm would probably retain nearly 100% of those larval fish that are at least 1.0 mm in body depth.

For the screen openings larger than 0.5 mm, average percentage retention (all species combined) appeared to be. -

largely dependent on average body depth (Fig. [13]). For each screen,'the minimum mean body depth which-resulted in' essentially 100% retention was fairly well defined (Fig. [13]) as follows:

Screen Opening (mm) Body Depth (mm) 0.5 < 0.7 1.0 ~ 1.8 1.3 2.4 1.8 2.8 2.5 > 4.6 In the stepwise analysis, body depth was included in the best single-variable model for all screer.s.

O

103 -

O Fityure 13 SCREEN OPENING s o imm SCA((N OPENING s l omm 10 0 SCREEN OPCHING a i.3mm

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2'O 2$ 3.0 I4 30 35 40 45 FISH 800Y OEPTH (mm)

General Rela:1cnsnio of Fish 51:e (mean tocy deotn) to etecte Petentiv Dy Scrten Coening. The cots represent the mettan percent retention (all sott'tes cccc.ine: exclucing juvenile threacfin snad) cc:urring in each mean size clus-The vertical lines cenote the one cuartile range on eitner side of t?e med14h O

104 -

In order to apply the work of Tomljanovich, et-a1. (1978) to the present situation, it is necessary to develop a length /

body depth relationship for the ichthyoplankton of interest <

From data collected by Jude, at al. (1978), the following table for alewife larvae was derived:

l l

Length (mm) Body Death 'mm) 5 0.3 10 1.0 15 1.4

, 20 2.0 1

25 2.8 Thus, a screen opening of 0.5 mm is likely to retain alewife O larvae 10 L'.; and greater in length, an opening of 1.0 mm is likely l to retain alewife larvae longer than 15 mm, and an opening of 2.0 l

mm would retain only larvae greater than 25 nmt in length. Since l Rago (1978) estimated that more than'97%-of the alewife larvae i

entrained at the Cook Kuclear Plant had body lengths less than 10 mm, any mesh size greater than 0.5 mm is not likely to exclude

-much alewife larval entrainment ct the plant.

L With respect to those larvae retained on the wedgewire screen, survival is directly pr rortional to the length of time spent impinged (Magliente, et al., 1978; Tomljanovich, et 1 1., 1978; Heuer and Tomljanovich, 1978), Tomljanovich, et al.

(1978) ran tests to measure short-term and long-term mortality -

4

)

as a function of impingentnt duration (see E igure 14).

Based on this work, -Impingement for longer than four minutes appears to

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' -le TEST DU R ATION (MINUTES)

Relationshic of Average Ieneciate Fatt-tes: Survival of Fish Imoinged on Fine-mesh Screens to Test Ouration. Fish si:ss, screen openings, and velocities were ccmcined.

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Figure 14

106 -

\/ ~ cause a substantial increase in mortality. This is very apparent from the long-term mortality study, where even shorter impinge-ment times appear to cause higher mortalities. In order to keep impinge. ment times be?ow four minutes, it would be necessary to backwash the screens overy four minutes;.this high frequency back-washing is to minimize impingement time, and not necessarily-to prevent screen fouling. If a bypass velocity higher than that likely to be present in the lake existed, there is the potential that the larvae might be swept from the screens without the need

.for such high frequency backwashing. But, unen again, given the massive _ size of the cylindrical wedgewire screens that would be-necessary for the Cook Nuclear Plant, there can be no assurances that adequate larval removal from the screens would occur even O if high bypass currents were prevalent in the lake.

Given that present entrainment mortality rates at the Ccok Nuclear Plant are significantly less than 100L of the en- -

trained ichthyoplankton -- and most probably only around 50%

(see pp. 4!b54 , _ supra ) -- it cannot be assumed that installation lof a fine mesh Johnson wedgewire screen would necessarily be_en-

-vironmentally preferable at the Cook Nuclear Plant. The estimate.

of present entrainment mortality must first be compared to the estimated number of ichthyoplankton likely to be killed through entrainment into, and.ilapingement on, the fine mesh Johnson screen.

We assume that-almost 100% of the ichthyoplankton can be' excluded from entrainment if a mesh size of 0.5 mm is utilized.

{]

If a larger mesh was used -- as, for e>. ample, 1.0 or 2.0 mm mesh

-- then,-depending on larvae and mesh size, less than 100% of

. .. . _ . _ _ _ . _ _ _ _ _ . . _ _ .. ... -. .m i

- 107 -

Q

- Ai) - the ichthyoplankton would be excluded. Those ichthyoplankton that are entrained will probably have a 100% mortality rate be-

-15/

cause of greater screen interaction.

With respect to those ichthyoplankton impinged on the fine mesh wedgewire screen,.a conservative analysis would recog-nize that a not insubstantial number would be killed prior to removal from the screen. A precise quantification of the antici-pated impingement mortality is complicated because studies have not been conducted on larval impingement where bypass current is low, as is the case in Lake Michigan, or where multiple in-take arrays are present, as would be needed at the Cook Nuclear Plant. Thus, there is a substantial need for extensive studies and models prior to any final design of a possible alternative O intake structure.

4, Summarv. The evaluation made by the Company of fine mesh wedgewire screens indicates that such an alternntive intake structuro-at the Cook Nuclear Plant would be neither- -

effective nor. feasible. The Company believes such screens:to

.be ineffective due to the very small size of the alewife larvae present at the site. With a 0.5-mm-screen opening necessary to exclude most alewife larvae, the likelihood of extended screen residence times and substantial biofouling or detrital fouling-15/

~~

Hanson, et al. (1978) indicated opercle damage on larvae ex-perienc2.ng extended impingement. Tomljanovich, et al. (1978) observed external injuries on impinged larv3e, but only 1.5% of in the fish had observable injuries. These were impinged and not U entrained larvae and the authors state thr' the injuries are too

.few to allow valid analysis.

--108 -

O indicate a high degree of impingement mortality. The use of larger mesa openings to avoid such problems would not signifi-cantly reduce present entrainment rates. Moreover, the Company does not believe that present entrainment losses result in ad-verse impact to the aquatic environment. With respect to feasi-bility, the Company believes the substantial costs associated with backfitting wedgewire screens, the technical problems and uncertainties in designing a system capable of meeting the water needs of the plant, and the general lack of reliability all augur against installation of such a system.

C. Fine Mesh Traveling Screens A second technology for which the MWRC Staff requested the Company to supply information is the fine mesh traveling screen. Fine mesh traveling screens are of two types: the through flow and the center flow. Through-flow screens are simply the installation of fine mesh screen material in place of the usual 3/ 8-inch mesh on the Rex Chainbelt screen system (see p. - 18, pupra) . Center-flow screens are also referred to as either single-entry, double-exit screens or Passavant screens (Beloit-Passavant Corp.). These screen systems can be equipped with a variety of screen mesh sizes, including fine mesh screens.

Passavant screen systems are similar to the Rex Chain-

, belt system in that panels are attached to two continuous chains.

The differences 4are that the Passavant screen panels are semi-cylindrical (convex), rather than flat, and the screens are

(])

parallel to the water flow. Figure 15 ir a schematic diagram of

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Design .f Lewar 3 rden af Passavant Screen Figure 15 O

- 110 -

L( ) a Passavant screen. Trash cannot be " carried over" to the other side.by the Passavant screens,-and the effective screening area is approximately doubled from the' Rex Chainbelt screens for a given water depth.

1. Existing fine mesh, center-flow screen insta?'.ations.

One installation of Passavant screens in the United States is at the Barney M. - Davis Generating Station. near Corpus Christi, Texas. Four Passavant screens are used to filt bris from the cooling water. Each screen' filters watcr at 6 t ate of about 85,000 gpm. The screen panels initially were made of polyester-monofilament screen cloth with 0.5 mm mesh openings. Due to severe mesh clogging-by a filamentous algea, these screens have recently been replaced by screens with a 1-mm opening. Water velocity

[]}-

1 rough the screen openings at 100 percent efficiency is - 0.5 -

meters /second and at 50 percent is 0.9 meters /second.

t A study was conducted'at the Davis Plant to determine '

the survival rate cf the dominant marine organisms impinged on o

the fine mesh screens during 1976 and 1377 (Murray and-Jinnette, 1978). The overall impinged fish survival rate was 86 percent.

ForLthe-five dominant = fish species, survival rates ranged from 67 l

L to 95% for the year. These figures do not, however, accurately reflect the survival rates of larval fish entrained at the Davis l Plant. Larvae were collected from the screen wash water with a l

L 1/8-inch (3.175 run) mesh net: (Murray and Jinnette, 1978). With a l

I sampling net mesh larger than the traveling screen mesh a certain Ij fraction of the larval fish were not sampled. The segment of the l

. - - ,_ - - - - __ .- ,,. ,.-..e

111 -

f)

larval fish popule: ion not sampled included the smaller more fragile life stAJes. Therefore, the survival estimates from the ,

study by Murrr,y and Jinnette probably had a significant bias, and most likely were higher than the survival rates if all life

\

stages hea been sampled. Moreover, tha survival rates found by Murray and Jinnette (1978) do not include mortality induced by the fish return system. The design problems associated with a fish return system (see pp .119-22 , _ufra), lead che Company to con-clude that slynificant mortality may be likely from such systmas.

The remainder of this section discusses a conceptual scheme for backfitting the Cook Nuclear Plant with fine mesh veling screens; the costs of i.nstallation and maintenance; the

.ign, engineering and installation of a fish-return system; and the environmental advantages and disadvantages of such a rystem.

Considering all the relevant factors, the Company does not be-lieve that installation of fine mesh traveling screens at the Cook Nuclear Plant is warranted.

2. Conceptual design for installation of fine mesh traveling screens at the. Cook Nuclear Plant. The Company initially undertook a study to determine if 1.0 mm mesh single-entry, single-exit traveling screens could be incorporated in the present Cook Nuclear Plant forebay. Preliminary fincings indicate that 28 traveling screens of this type would be required as opposed to 14 screens presently installed. This would necessitate doubling the intake houce area to accommodate this scheme. It also is likely that baffling would have to be added in the forebay in order to maintain flow patterns conducive to proper pump opera-

_ _ _ _ _ _ . . _ ~. _ .._.. _ ..._. _ _ _ .._ _ _. _ _ _ . .

x

- 112 -

tion. A.model study would be required.to determine the type and configuration of baffling required. The extensive forebay. modi-fication required by this scheme appears ~ to eliminate this a.1-ternate as a viable alt 7rnate intake system.

The company, therefore, un9artook to determine if tan Passavant type traveling screen cJudd be incorporated into the present Cook Nuclear Plant forebay.- Preliminary findings indi-cate that it would be possible- to incorporate 14 Passavant-type screens into the existing forebay area. Structural modifications of the forebay area would be required due to the different orienta-tion of the Passavant screens. Also extensive model testing would be required to ensure that hydraulic patterns conducive to proper.

pmap operation are maintained within the forebay area.

In order to estimate construction costs, it was assumed

.that each Passavant screen assembly would be lowered into position in its bay with a 30-ton overhead crane. Since crane clearance will only allow the handling of.a 33-foot high section, the'46-foot high Passavant assemblies will have to 132 = furnished as sub-assemblies, approximately 23 feet high. Screen supports would be' anchored to their adjacent pier walls, the half sections would then be bolted at the provided split flanges, and the assemblies grouted into place. Preliminary layouts are shown in Figures 16 l through 18.

l: With the use of Passavant traveling screens baffle and l

l guide walls are necessary when the exit wall of the screen is

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within 36 feet of the pump bellmouth (Roberge, 1977). Since this would be the case at the Cook Nuclear Plant, the installa-tion cost of baffles has been included. Several of the existing piers would be extended for use as baffle supports and flow guides. This modification would require approximately 400 cubic yards of Class I - Seismic concrete and the drilling and installa-tion of an estimated 370 #11 anchors, each with a 2-foot embed.

The bulk of this installation work wouJd need to be performed underwater, therefore necessitating the use of divers. This sub-stantially increases installation costs.

The installation of fine mesh traveling screens also would require the . addition of low-pressure wash jets to remove eggs and larvae which would become impinged on the screens and O some form of fish return system. The existing high-pressure screen wash system would be maintained to remove more adherent trash. The details of the fish return system are difficult to l project (see pp. U.9-22, infra) , - although for purposes of develop-ing a cost. estimate,-it can conservatively be assumed that a-new sluiceway and piping extending approximately 1000 feet into the lake would be required to return adult fish, larvae, eggs and crash to the lake. It-appears that the most efficient method of re-turning impinged organisms to the lake, and the least damaging, is by the use of -peripheral-type jet pumps. Extensive testing l would-be required to develop a jet pump suitable for this appli-cation (see p. 121 , infra).

Given the conceptual design described above, a pre-liminary cost estimate was made for the Passavant retrofit.

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- 117 -

O Cost estimates of various components were obtained from: (1) the Passavant screen manufacturer; (2) a hydraulic modeling laboratory, which has done previous studies of the Cook Nuclear Plant circulating water system and which has modeled the single-entry, double-exit screen; (3) an installation contractor, who has been engaged in various construction activities at the Cook Nuclear Plant for more than ten years; and (4) the AEPSC Civil Engineering Division, particularly in reference to the expected baffle configuration.

The estimated costs sf the Passavant screening elements for the Cook Nuclear Plant is approximately $2,500,000 for 1.0 mm screening elements and $2,750,000 for 0.5 mm screening elements.

Structural modification, installation, and additional support O systems required are additional costs. It is estimated that materials for the water guides and baffles would cost about S1,750,000, and the hydraulic model study would add an additional

$100,000. Installation costs, including misellaneous materials, would be a further $3,900,000. This is based on 1979 wage rates, fuel, and material costs as of July 1979, and is subject to annual increases of 10% to 12% due to inflation. As explained below ( s ee pp . 119-22 , infra), the Company is uncertain whether it is possible to design a fish return system that would provide for the safe return of impinged larvae. Therefore, no cost estimate of such a system has been provided; the costs, however, of such a system are likely.to be substantial. The estimated total cost (excluding the fish return system) , but including allewances for

[)

engineering, administrative and contingency, is $11,860,000 to l

I

- 118 -

() $12,225,000, depending on mesh size. Neither the cost of capital nor inflation is included in this estimate.

I addition, there are substantial added maintenace costs associated with the Passavant screens. The manufacturer has recommended that the screens be operated continuously for proper performance. This 24-hour per day operatior. obviously results in maintenance requirements far above those required for -

traveling screens which are operated intermittently. The United States operating experience with this type of screening is very limited; however, it appears that maintenance costs of $15,000 to S20,000 per yect per screen can be expected -- or about $250,000 per year.

It may be possible to install the Passavant traveling '

screens without an entire plant shutdown. Possibly a cutoff wall, isolating Unit 1 from Unit 2, could be installed so as to enable the installation of several of the Passavant screen assem-blies while the other unit functioned on the cooling water fur-nished by the original intake system. Several analyses would have to be conducted in order to ensure the feasibility of such plant operation. If this approach proves feasible, it would be necessary to shut each unit down for about two and one-half months to perform the work. The cost of this shutdown is esti-mated at $3 to S3.5 million per week, per unit; it, of course, must be added to the prior costs to develop the total cost of back-fitting Passavant screens at the Cook Muclear Plant.

() 3. Biological effectiveness of fine mesh traveling l

screens. As was true with the wedgewire screen alternative ( s_e_e i

- 119 -

pp.99-107, supra) , impingement mortality associated with a fine -

mesh traveling screen must be assessed against entrainment mor-tality from the present intake system. Mesh size and larval impingement duration would have the same-importanca for fine mesh traveling screens as in the case of the wedgewire screens. Thus, a mesh size of 0.5 mm would be needed in order to exclude the ichthyoplankton currently entrained. Further, the screens would have to complete a rotation every four minutes in order to maxi-mize impingement survival. All of these factors affecting mor- '

tality must be evaluated so_that a comparison can be made between the present number of ichthyoplankton killed due to entrainment and the future number of ichthyoplankton impinged and entrained with-fine mesh traveling screens. The concerns expressed by the O Company as to the biological effectiveness of the wedgewire screens apply with equal force for the fine mesh traveling screen.

In addition, however, the use of an onshore screening system to reduce ichthyoplankton mortality will require a return system that would carry adult fish, trash and ichthyoplankton back-to Lake Michigan.- It is necessary for this system to be able to carry all of the screen wash because separation of the various organisms and debris would increase mortality. This system will have to be designed so as to deliver the adult fish and ichthyoplankton from the screens across the beach and beyond -

the' storm surf zone. The depth of discharge and pressures to be encountered must be carefully considered in the design so as not to-induce additional mortality.

f])

, Fish return systems have been studied by Taft, et al.

(1976);_ White and Brehmer (1976); Mussalli and Taft (1977);

l 1

- 120 -

) Mussali, et al (1977); and Mussalli, et al. (1978). The' fish return system that would be used at the Cook Nuclear Plant has not yet been designed. This is becau' it is not yet known exactly how the fish and larvae will be returned; testing ob-viously will be required prior to any final design. The major ,

components of a fish return system probably would include (a) a low-pressure screen wash system; (b) an additional trash trough; (c) a jet pump (peripheral type); (d) smooth interior piping

' ( i-. e . , fiberglass); and _(e) a discharge structure capable of surviving the lake conditions. Each of these components is described below.

l (a) Low-oressure screen wash system 1

(]) The low-pressure screen wash is necessary for increased survival. Currently, the Cook Nuclear plant screen wash system operates at 80 psig. A low-pressure, 15 to 20 psig (White and Brehmer, 1976) screen wash system would be needed to prevent physical damage to impinged organisms.

(b) Additional trash trough The additional trough would collect the low-pressure screen wash water and Jirect this water, with impinged organisms, to the piping which would return the impinged organisms to the lake. Currently, both the NRC operating licenses and the MWRC discharge permit do not allow the discharge of the screen wash no Lake Michigan; these permits would have to be modified. All screen wash, including debris, abould be returned to the lake, since larvae and eggs can adhere t6, and become entangled in, decris (Mussalli, et al. 1978).

.. - - - . .. - . - ~ _ - .. . - _ . _ _ - . . _ .

- 121 -

(c). Jet cump (peripheral type)

A peripheral type jet pump would be needed to move the impinged organisms back to the lake. This type of pump was investigated by Taft, et al. (1976). Using a drive nozzle velocity of 30 ft/sec, less than 10% mortality occurred. High velocities increased physical damage but no exact mortality figures were given; the fish tested were 2- to 5-inch alewife and smelt juveniles. Currently, the design of a single jet pump,

'or a number of smaller pumps, with a capacity to handle the screen wash water at the Cook Nuclear Plant is unknown. It is not certain if this pump would cause greater mortality to larval stages, especially with the relatively large hard objects in the screen wash.

.O The need to bury the screen wash return piping under the beach precludes the use of a gravity flow return.

(d) Smooth interior piping (i.e., fiberglass)

Piping from the screenhouse to the lake discharge would have to be buried under the beach and run under the lake bed to a point beyor.d the storm surf. This location would be approximately 1000 feet c.'fshore. The interior of the pipe would be of a smooth material, such as fiberglass. This would

. minimize the' shear force and abrasion occurring to an organism ,

passing through the system. All bends in the pipe would have i

-to be large diameter curves.

5 (e) Discharge structure capable of surviving the lake conditions A discharge structure which could withstand the rigors

- 122 -

of the lake environment would be required. Basically such a structure can be_ viewed as the end of a pipe angled 1toward the-surf ace. and anchored with concrete. Being only a conceptual step, further design must be done to ensure that the discharge would not become filled by sediment while~the system is not operating, damaged by ita, or expose the organisms _to unnecessary pressure changes.

Resolution of the design issues identified above is not trivial. Many of the fish handling systems that have been de-signed are for transporting juvenile and adult fish. There is a great need to evaluate a larval fish handling system that could _ transport previously impinged larvae well offshore prior to any final design of a system that might be used at the Cook Nuclear Plant. Moreover, the additional mortality that would be induced by the fish return system has to be added to the mor-tality caused by impingement on the fine mesh screens, and this total mortality must be ' compared to the mortality that is cur-rently_occurringLwith the existing circulating water system, in order to assess the true environmental impacts of this alterna-tive. 1This conclusion is shared'by Sharma (1978). In his recommendations, he. states:

Fine-mech traveling screens offer long-term,

-proven technology. However,' biological ef-fectiveness for the-whole cycle, from impinge-ment _to survival in the sou_ce water body, should be investigated thoroughly prior to implementation of this option.

O 4. Summary. Backfitti'ng the Cook Nuclear Plent with fine mesh traveling screens is not justified. Such an alternative

- 123 -

would suffer from the same concerns'over biological-effectiveness as the.wedgewire screen (see pp.99-107, supra), and, in addition,

-would raite further concerns as to the feasibility of.the fish' return system. New designs ana technology (especially with res-spect to the jet pump) would have to be developed to implement a satisfactory fish return system. .

Moreover, the Company harbors concerns over the opera-tional reliability of fine mesh traveling screens-given the high ,

loading of debris sometimes present at the site. Even under good conditions, the continuous operation of the screens would recuire special maintenance. The added costs of such maintenance, plus the cost of backfitting fine mesh-screens, further confirm our view that implementation of this alternative is unjustified.

ii:

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- 124 -

V. CONCLUSION The-Company's position is fairly simple: the existing Cook Nuclear Plant cooling water intakes reflect the best tech-nology available for minimizing adverse environmental impact be-cause (a) the present level of entrainment losses do not adversely affect the aquatic environment; and (b) at the time of intak'e de-sign, there existed no intake technology for once-through cooling systems capable of reducing larval entrainment. These two conclu-sions require the MWRC to approve the section 316(b) demonstra-tion submitted by the Company for the Cook Nuclear Plant.

Moreover, a full evaluation of all alternative intake structures' discloses - no design superior to that presently installed

() at the Cook Nuclear Plant. The two alternatives suggested by the MWRC Staff -- cylindrical wedgewire screens and fine mesh travel- ,

ing screens -- suffer from a number of problems, including: high cost,-uncertain technology, and low reliability. Nor in the company's view are such alternatives likely to result in signi- -

ficantly less larval mortality than that now associeted with the present intake structures.

For all these reasons, the Company respectfully requests the MWRC, pursuant to section 316 (b) of the Clean Water Act, to find that the Cook Nuclear Plant cooling water intake structure reflects the best technology available for minimizing adverse environmental impact.

References Cited Cannor. T.C., S.M. vinks, L.R, King, ar.d G.J. Lauer. 1978. Sur-

. . . of Entrained Ichthyoplankton and Macroinvertebrates at

• ud: 1 River Power Plants. Fourth National Workshop on En-

• r. lent and Impingement. Loren D. Jensen, ed. E.A. Com-

.. .ations, Melville, New York. 424 pp.

Christensen, S.W., D.L. DeAngelis, and A.G. Clark. 1977. De-velopment of a Stock-Progency Model for Assessing Power Plant Effects on Fish Populations. W. Van Winkle, ed.

Proc. Conf. Assessing the Effects of Power Plant Induced Mortalitv on Fish Populations. Gatlinburg, Tennessee. 3-6 May 1977. 300 pp.

Coutant, C.C. and R.J. Kedle. 1975. Survival of Larval Striped Bass Exposed to Fluid Induced and Thermal Stresses in a Simulated Condenser Tube. ERDA Report No. ODNL-TM 4695 Oak Ridge, Tennessee.

Dahlberg, M.D. 1979. A Review cf Survival Rates of Fish Eggs and Larvae in Relation to Impact Aasessments. Marine Fish-gs cries Review (March 1979) . U.S. Dept. Commerce, National

(_) Marine Fisheries Service. 12 pp.

Downs, D.I. and K.R. Meddock. 1974. ".ngineering Application of Fish Behavior Studies in the Design of Intake Systems for Coastal Generating Stations. ASCE National Water Resources Conference. 30 pp.

Dryer, W.R., L.F. Erkkila, and C.L. Tetyloff. 1965. Food of the Lake Trout in Lake SuperLor. TranJ. Amer. Fish Soc. -

94:169-176.

Ecological Analysts. 1979. An Assessment of the Potential fo.

Ichthyoplankton Entrainment Survival at the Muskingum River Plant., unpublished draft report for American Electric Power Service Corp. frMa Ecological Analysts, Inc. Middletown, New York. 22 pp, and appendices.

EPRI. 1979. Er:trainment: An Annotated Jibliography. Prepared by Oak Ridge National Laboratory an- Atomic Industrial Forum, Inc. EA-1049; RP877 Palo sito, California. 193 pp.

Fisher, F.W., D.B. Odenweller cnd J.E. Skinner. 1976. Recent Progress in Fish Facility Research foi California Water Diversion Projects. In Third Nat'l Wor.' hop on Entrainment and Impingement. Loren D. Jensen ed. Eco_ogical Analyats, Inc., Melville, New York.

(~}

v

)

I I

I References Cited  !

Page 2 -

O Goody".r" C.P. 1978. Entrainment Impact Estimates Using the

.quivalent Adult Approach. Power Plant Project, Offic6 Biol. Serv., Fish and Wildl. Serv., U.S. Dept. Interior.

FWS/OBS-78/65. 14 pp.

Goodyear, C.P. 1977. Assessing the Impact of Power Plant Mor-tality on the Compensatory Reserve of Fish Populations.

W. Van Winkle, ed. Proc. Conf Assessing the Effects of f Power Plant Induced Mortality on Fish Populations. Gatlin-Larg, Tennessee. 3-6 May 1977. 380 pp. '

Grossnickle, N.E. and M.D. Morgan. 1979. Density Estimaten of Mysis relicta in Lake Michigan.

-~ J. Fish Res. Board Can.

36:694-698.

Han n, C.H., J.R. White, and H.W. Li. 1977. Entrapment and Impingement of Fishes by Power Plant Cooling-Water Intakes An overview. Marine Fisheries Review. 39 -(10) , pp. 7-17. ,

Hanson,_ B.N., W.H. Basene 9.E. Beit:- and K.E. Charles. 1978A.

Studies of Profile-Wiro Ocreen as Surface Water Intakes.

Special Report for Delmarva F0wer and Light Co. by Ichthyo-logical Assoc., Inc. Ithaca, New /ork. 178 pp.

(]) Hanson, D.H., W.H. Bason, L.E. Beit: and K.E. Charles. 1978B.

Practicality of Profile-Wire Screen in 3 educing Entrainment and Impingement. In Larval Exclusion Systems for Power 3 Plant Cooling Water Intckes. R.K. Sharma Ond J.B. Palmer eds. San Diego, California, pp. 195-234.

Hatch, Richard W - 1979.-

Estimation of Alewife Biomass in Lake Michigan, 1967-1978. Administrative Report, Great Lakes Fishery Laboratory, U.S. Fish s- Wildlife Service, Ann Arbor, - !

Michigan. 31 pp.

Heuer, J.H. and D.A. Tomljanovich. 1978 A Study on the Protec-tion of Fish Larvae at Water Intakes Using Wedge-Wire Screnn-

• ing. In Larval Exclusion Systems for Power Plant Cooling-WaterLintakes. R.K. Sharma and J.B. Palmer, eds._ San Diego, California, pp. 169-194.

Indiana & Michigan P'mer Company. 1975. Plan of Study and Demon-stration Concerning T_, mal Discharges at the Donald C. Cook Nuclear Plant. Submitted to the Michigan' Water Resources Commission. April 7, 1975.

Indiana &-Michigan Power company. 1977. Report on the Impact of Cooling Water Use at the Donald C. Cook Nuclear Plant. Sub-mitted to the MWRC, 1/1/77. 194-pp.

Johnson Division,-UOP, Inc. 1977. Johnson Screens in Surface Water Intake Systems. Sales Erochure. St. Paul, Minnesota. '

b

- - . - - ==,<a.s.,w ---m www- t.m -,,4-.-ws -, -e-r-w,r~w- ~w,w.er---r----=v---.m-e,w.w-.,-y-.w.e., e-~,w,% ,w,.w, y ..

---i,---ym,w, ,*m v. p yr%-vn,.-,-y,-v

i References Cited Page 3 Jude, D.J., B.A. Bachen, G.R. Heufelder, H.T. Tin, M.H. Winnell, P.J. Tesser and J.A. Dorr. 1978. Adult and Juvenile Fish, Ichthyoplankton and Benthos Populations in the vicinity of

+he J.H. Campbell Power Plant, Eastern Lake Michigan, 1977.

University of Michigan, Great Lakes Resource Division. ,

Special Report No. 65. 639 pp.

Jude, D.J., F.J. Tosar, J.A. Dorr III, T.J. Miller, P.J. Rago, D.J. Stewart. 1975. Inshore Lake Michigan Fish Populations Near the Donald C. Cook Nuclear Power Plant, 1973. Special Repoet No. 52. Great Lakes Research Division, Univ. of Mich., Ann Arbor. 267 pp.

Jude, D.J. 1975. Entrainment of Fish Larvae and Eggs on the Great Lakes, with Special Reference to the D. C. Cook Nuclear t Plant,-Southeastern Lake Michigan. Contribution No. 202, Great Lakes Research Division, Univ. of Mich., Ann Arbor.

29;pp.

Kerr, J.E. 1953. Studies on Fish Preservation at Contra Costa Steam Plant of the Pacific Gas and Electric Company. Ca.

Dept. of Fish and Game, Fish Bulletin 92. Sacramento,  ;

California.

Kiss 11, G.W. 1974. Spawning of the Anadromous Alewife Alosa ,

pseudoharengus in Bride Lake, Connecticut. Trans. Amer?

• Fish. Soc. 103(2):312-317.

Magliente, S.H., D.A. Tomljanovich, J.H. Heuer, S. Vigander and '

M.N. Smith. 1978. Investigations on the Protection of Fish Larvae at Water Intakes Using Fine Mesh Screening. Impinge-ment Release Concept: Laboratory Study of a Single En- ,

trance, Double Exit Vertical Traveling Screen Concept. In Larval Exclusion Systems for Power Plant Cooling Water In-takes. R.K. Sharma and J.B. Palmer eds. San Diego, California, pp. 69-77.

.Marcy. B,C., Jr. and M.D. Dahlberg. 1978. Review of Best Tech-nolc.gy Available for Cooling Water Intakes. Prepared for Dept. of Water and Power City of Los Angeles. NUS Corp.

Pittsburgh, Pennsylvania. 90 pp.

McFadden, J.T. 1977. ha Argument Supporting the Reality of Com-L pensation in Fish Populations and a Pica to Let Them Exer-

! cise It. (ed.) W. Van Winkle. Proc. Conf. Assessing the Effects of Power Plant Induced Mortality. Gatlinburg, Tennessee. 380 pp.

l Miller, J.C., K.E. Charles and T.H. Key. 1978. In-Situ Testing

's of Profile Wire Screens for Long Term Engineering Feasibility.

In Larval Exclusior. Systems for Power Plant Cooling Water Intakes. R.K. Sharma and J.L. Palmer, eds. San Diego, j California, pp. 159-167.

..m . . . _ _ _ _ . _ _ _ _ . _ -__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

l References Cited

() Page 4 Morgan, R.P. 1974. Testimony before the Federal Power Commission, Oct. 1974. Project No. 2338 (Cornwall). pp. 4,715-4,816.

Murray, L.S. and T.S. Jinneete. 1978. Survival of Dominant Estuarine Organisms Impinged on Fine-Mesh Traveling Screens '

at the Barney M. Davis Power Station Proc. Larval Exclu-  ;

sion Systems for Power Plant Cooling Water Intakes Workshop.

San Diego, California. 7-8 Feb. 1978. NUREG/CP.002, ANL/ES.  !

Mussa111, Y.G. and E.P. Taft. 1977A. Fish Return Systems.

Presented at 25th Annual Hydraulics Division Specialty Con-ference, ASCE, August 1977. 8 pp.

Mussa111, Y G., P. Hofmann, E.P. Taft. 1978. Influence of Fish Protection Considerations of the Design of Cooling Water Intakes. Presented at Joint International Symposium on Design and Operation of Fluid Machinery. June 12-14, 1978. 11 pp.

New York University Medical Center. 1974. The Effects of Change in Hydrostatic Pressure on Some Hudson River Biota. Prog-ress Report for 1974. Consolidated Edison of New York.

() New York University Medical Center.

ment Simulator Utilizing a Condenser Tube Simulator; Results 1979. Power Plant Entrain-of Exper/ mental Exposure of Striped Bass Early_ Life History Stages, Gammarus spp. and Neomysie americana to Variations in Temperature, Flow Rate and Biocido Concentrations. Pre-pared for N.Y.S.' Energy Research and Development Authority.

N.Y.U. Med. Center, Inst. of Env. Med., Lab. for Env. Studies.

New York, New York.

Rago, P.J. 1978. On the Calculation of Production Foregone Due to Entrainment and Impingement of Fishes at the Donald C.

Cook Nuclear Plant. Great Lakes Research Divisicn, Uni-versity of Michigan, Ann Arbor, Michigan. (unpublished manuscript).

Peyut ' ds , J.D. and G.M. DeGraeve. 1972. Seasonal Population l tharacteristics of the Opposum Shrimp, Mysis reljeta, in ~

Southeastern Lake Michigan, 1970-1971. Proc. TFth conf.

Great Lakes Res. pp. 117-131. -

Richards, R.T. 1977. Present Engineering Limitations to the Protection of Fish at Water Intakes. In Fourth Nat'l Work-shop on Entrainment and Impingement. L.D. Jensen ed.  ;

Ecological-Analysts. Melville, New York. 424 pp.

Schuler, V.J. and L.E. Larson. 1974. Experimental Studies l O Evaluating Aspects of Fish Behavior as Parameters in the Design of Generating Station-Intake Systems. ASCE Water Resources Engineering Conference. 35 pp.

1 References Cited Page 5 Sharma, R.K. 1978. Larval Exclusion Systems for Power Plant Cooling Water Intakes: A Synthesis of Views Presented at Cooling Water Intakes Workshop. R.K. Sharma and J.B.

Palmer eds. San Diego, California, pp. 235-237.

Taft, E.P., P. Hofmann, P.J. Eisele, and T. Horst. 1976. An Experimental Approach to the Design of Systems for A11eviat-ing Fish Impingement at Existing and Proposed Power Plant Intake Structures. In 3rd National Workshop on Entrainment and Impingement. Loren Jensen ed. Ecological Analysts, Inc.

Melville, New York 425 pp.

U.S. Environmental Protection Agency. 1976. Development Docu-ment for Best Technology Available for the Location, Design, Construction and Capacity of Cooling Water Intake Structures for Minimizing Adverse Environmental Impact. Washington, D.C. 263 pp.

Vigander, S. 1978. Current TVA Work on the Fluid Machanics of Screens with very small openings for the Exclusion of Larval at Power Plant Cooling-Water Intakes. In Larval Exclusion Systems for Power Plant Cooling Water Intakes. R.K. Shanaa and J.B. Palmer eds. San Diego, California, pp.91-107.

O Weight, R.H. 1958. ocean Cooling Water System for 800 Mw Power Station. J. Power Liv. ASCE 84(6) 1808 1888-22.

Wells, L. and A.M. Beeton. 1963. Food of the Bloater, Coregonus hoyi, in Lake Michigan. Trans. Amer. Fish Soc. 92:245-255.

~

White, J.C., Jr. and M.L. Brehmer. 1976. Eighteen-Month Evalua-tion of the Ristroph Traveling Screens. In 3rd National Workshop on Entrainment and Impingement. Loren D. Jensen ed. Scological Analysts, I1c., Melville, New York. 425 pp.

O l

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