Tetra Tech, Inc.

10306 Eaton Place, Suite 340

Fairfax, VA 22030

phone 703-385-6000

fax 703-385-6007

DATE: July 3, 2008

TO: Paul Shriner and Jan Matuszko

FROM: Christine Wong, Kelly Meadows and Shari Goodwin, Tetra Tech

SUBJECT: Design Intake Flow for Test Cooling Water Intake Structures

Introduction

After reviewing technology efficacy studies 

impingement mortality data, EPA and Tt identified 

efficacy of Ristroph-type coarse mesh traveling screens. 

technology-based limits, EPA requested that Tt determine the intake flows that 

correspond to the study periods

clear in describing the test conditions, including the intake flows withdrawn during 

testing. As such, Tt was tasked 

reviewed the studies and other supporting documentation (including summary reports, 

primary studies, and information from 

flow (DIF) of the cooling water intake structures (CWIS) 

reviews are presented in the table on the following page.

Degree of Confidence

Tt is reasonably confident that the DIFs for the Dunkirk and Huntley 

because the design capacity is explicitly stated for the study screens at each facility.

(Whether the screens operated at

assuming they were.)

Based on the information available, Tt used its best professional judgment to assign a 

CWIS-specific DIF to the Arthur Kill and Salem studies. 

representatives at both facilities

communication efforts have not been successful with either facility. If and when contact 

is made with the facility representatives and DIF assumptions are confirmed, T

amend the table as necessary.

MEMORANDUM

10306 Eaton Place, Suite 340

and Jan Matuszko, EPA

Christine Wong, Kelly Meadows and Shari Goodwin, Tetra Tech

Design Intake Flow for Test Cooling Water Intake Structures

technology efficacy studies in the June 23, 2008 memo from Battelle

, EPA and Tt identified 6 studies that best represent

type coarse mesh traveling screens. To enable the development of 

, EPA requested that Tt determine the intake flows that 

correspond to the study periods in these documents. None of the studies were completely 

ear in describing the test conditions, including the intake flows withdrawn during 

testing. As such, Tt was tasked with determining an estimate of the flow rates. 

reviewed the studies and other supporting documentation (including summary reports, 

ary studies, and information from industry surveys) to determine the design intake 

flow (DIF) of the cooling water intake structures (CWIS) tested. The results of Tt’s study

reviews are presented in the table on the following page.

Tt is reasonably confident that the DIFs for the Dunkirk and Huntley studies are correct

capacity is explicitly stated for the study screens at each facility.

(Whether the screens operated at the DIF for the entire study period is unknown; Tt is 

Based on the information available, Tt used its best professional judgment to assign a 

DIF to the Arthur Kill and Salem studies. Tt has attempted to contact 

both facilities to confirm these assumptions. At this time, 

communication efforts have not been successful with either facility. If and when contact 

is made with the facility representatives and DIF assumptions are confirmed, T

.

Christine Wong, Kelly Meadows and Shari Goodwin, Tetra Tech

, 2008 memo from Battelle for 

best represent the 

To enable the development of 

, EPA requested that Tt determine the intake flows that 

. None of the studies were completely 

ear in describing the test conditions, including the intake flows withdrawn during 

the flow rates. Tt

reviewed the studies and other supporting documentation (including summary reports, 

surveys) to determine the design intake 

The results of Tt’s study

studies are correct, 

capacity is explicitly stated for the study screens at each facility. 

own; Tt is 

Based on the information available, Tt used its best professional judgment to assign a 

has attempted to contact 

communication efforts have not been successful with either facility. If and when contact 

is made with the facility representatives and DIF assumptions are confirmed, Tt will 
Facility 

Name

Generating 

Units/CWISs

DIF for Test 

CWIS Screens

Notes Data Source(s)

Arthur 

Kill

Unit 20 87 MGD Each unit contains 4 screens; only one of the four screens was upgraded 

for the study. No information provided on unit operation during study; 

assume that the flow through the upgraded test screen was 0.25 the 

maximum flow for the unit (347.9 MGD – provided in study), or 87 

MGD.

EPRI 2007

Unit 30 85 MGD Each unit contains 4 screens; only one of the four screens was upgraded 

for each study. No information provided on unit operation during study; 

assume that the flow through the upgraded test screen was 0.25 the 

maximum flow for the unit (339.3 MGD – provided in study), or 85 

MGD.

EPRI 2007

Dunkirk Screenhouse 

#1, including 

Units 1 and 2

92.2 MGD Modifications were made to one of three existing screens. No information 

provided on unit operation during study; assume flow through the test 

screen at maximum capacity. 92.2 MGD specified as prototype study

screen capacity.

Beak Consultants, Inc., 

2000 (DCN 5-4327)

Huntley Units 67 and 

68

82.8 MGD All (4 existing) screens replaced at Units 67 and 68 with 5 Ristroph-types 

screens. No information provided on unit operation during study; assume 

flow through the test screen at maximum capacity. 82.8 MGD specified 

as prototype study screen capacity.

Beak Consultants, Inc., 

2000 (DCN 5-4325)

Salem Unit 1

(1995 study)

266.4 MGD No information provided on unit operation during study; assume flow 

through the test screen at maximum capacity. 266.4 MGD specified as 

Unit 1 design flow rate; 1995 study looked only at performance of Unit 1 

screens. 

Ronafalvy, Cheesman, 

and Matejek, 2000 

(DCN 5-4333)

Units 1 and 2

(1997-1998 

study)

532.8 MGD No information provided on unit operation during study; assume flow 

through the test screen at maximum capacity. 266.4 MGD specified as 

flow rate at each unit; 1997-1998 study looked at performance of screens 

at both Unit 1 and Unit 2 for a total DIF of 532.8 MGD.

Ronafalvy, Cheesman, 

and Matejek, 2000 

(DCN 5-4333)