Status, Impacts and

Operations of High-Salinity

Wet Cooling Towers

Mike DiFilippo

John Maulbetsch

Kent Zammit
2

Overview

• Sponsor: CA Energy Commission Public Interest

Energy Research Program

• Review of known or proposed CT’s using seawater,

brackish water, or other high-salinity sources

• Design and operating characteristics

• Environmental issues

• Specifics of some current installations, proposed

projects
3

Saltwater Cooling Towers in the US

Plant Size

(@ 500gpm/MW)

(m3/hr) gpm MW

1973 Atlantic City Electric Co. (NJ) Beesley's Point 14,423 63,351 127

1976 Public Service Electric & Gas Hope Creek 250,760 1,101,431 2,203

1981 Jacksonville Electric Authority Jacksonville 112,520 494,230 988

1990 Florida Power Corp. St. Petersburg 156,000 685,210 1,370

1992 Atlantic City Electric Co. (NJ) B. L. England 16,280 71,508 143

1999 Florida Power Corp. Crystal River 67,229 295,295 591

2000 St. John's River Power Park Jacksonville (FL) 56,258 247,106 494

Flow Year Owner Site
4

Brackish Water Cooling Towers in the US

Year Owner Site

Equiv. Plant Size

(@ 500gpm/MW) HWT CWT WB Approach Range

(m3/hr) gpm MW F F F F F

1953 Oklahoma Gas & Electric Oklahoma 13,680 60,088 120 104.0 86.0 75.0 11.0 18.0

1964 American Salt Co. Kansas 1,140 5,007 10 89.6 81.0 75.2 5.8 8.6

1968 Exxon Chemical New Jersey 5,016 22,032 44 111.9 82.0 75.0 7.0 29.9

1971 Gulf Power Florida 37,620 165,241 330 121.6 91.0 82.8 8.3 30.6

1973 Dow Chemical Texas 13,680 60,088 120 109.0 86.9 80.1 6.8 22.1

1974 Potomac Elctric Chalk Point 3, MD 59,280 49 32 120.0 90.0 78.1 11.9 30.1

1975 Virginia Electric Virginia 75,240 330,482 661 113.0 89.1 78.1 11.0 23.9

1975 Pfizer North Carolina 12,442 54,650 109 100.0 87.1 80.1 7.0 13.0

1976 Dow Chemical California 2,736 12,018 24 105.1 78.1 70.0 8.1 27.0

1976 Italco Aluminum Washington 9,348 41,060 82 98.1 84.9 73.0 11.9 13.1

1976 Pacific Gas & Electric Pittsburg, CA 84,816 372,543 745 100.0 82.0 70.0 12.1 18.0

1977 Houston Lighting & Power Texas 54,720 240,351 481 109.9 94.5 82.0 12.4 15.5

1980 Mississippi Power Plant Jackson 39,444 173,253 347 120.0 90.0 80.1 9.9 30.1

1981 Potomac Electric Chalk Point 4, MD 59,280 260,380 521 120.0 90.0 78.1 11.9 30.1

1985 Palo Verde I Arizona 133,836 587,857 1,176 118.8 87.3 77.0 10.3 31.5

1986 Palo Verde II Arizona 133,836 587,857 1,176 118.8 87.3 77.0 10.3 31.5

1986 Stanton Energy #1 Florida 45,600 200,292 401 113.7 91.0 78.1 13.0 22.7

1987 Palo Verde III Arizona 133,836 587,857 1,176 118.8 87.3 77.0 10.3 31.5

1987 Houston Lighting & Power Texas 54,948 241,352 483 109.9 94.5 82.0 12.4 15.5

1989 Delmarva Power & Light Delaware 46,170 202,796 406 116.8 90.0 79.0 11.0 26.8

1991 Delano Biomass California 4,423 19,427 39 98.1 82.9 72.9 10.1 15.1

1995 Stanton Energy #2 Florida 45,600 200,292 401 113.7 91.0 78.1 13.0 22.7

Flow
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Performance of Saline Cooling Towers

• Higher salinity reduces CT performance

– “Rule of Thumb”- 5% capability reduction for a salinity of

50,000 TDS (Aull, R. 2005)

– CTI journal article suggesting a performance loss of

5.4% at a salinity of 50,000 TDS. Also refers to

publication of a Fluor paper recommending increasing

the design wet bulb by 0.055ْ C (~ 0.1ْ F) for each 4,000

ppm of dissolved solids. For sea water operating at 1.2 -

2 cycles of concentration, this corresponds to an

increase in the design wet bulb of 0.55 - 1.1ْ C ( ~ 1 - 2ْ

F) - (Eftekharzadeh, S.; M. Baasiri; P/ Lindahl. CTI

Journal 2003, 24, 50-64)
6

Recommendations for High Salinity Towers

• Fiberglass structure – no timber.

Reinforced concrete OK, too, but use

epoxy coated rebar and proper

concrete mix

• Low TSS seawater – use high

efficiency fill, High TSS water – use

inverted-V splash fill

• Metal components – epoxy coated

carbon steel

• Hardware – silicon bronze with plastic

caps for erosion protection, or 316SS

(costly)

• Most use titanium condensers Mirant Chalk Point Towers
7

Insights from Individual Facilities

Pittsburgh Plant, California

• Units 5,6,&7 – 1300 MW with helper tower

• TDS in summer as high as 17,000 mg/l

• Total hardness 1500-1700 mg/l CaCO3

• High colloidal organics

• 1.3-1.4 COC all year long

• Winter: TDS 100-100mg/l, but TSS can be 200mg/l

• Wood tower with plastic, high efficiency fill,

• No bio control, pH control or scale/corrosion control

• Some thermal degradation in some cells, attributed to fill

bypass
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Insights from Individual Facilities (cont.)

Palo Verde Nuclear Generating Station, Arizona

• Three 1300 MW units, circular cross-flow towers

• Secondary treated effluent from Phoenix

• Trickling filtration (organics, ammonia and TSS

reduction), lime/soda ash softening, final filtration

• Operated at 24 COC, sometimes to 30 COC

• CT’s are reinforced concrete, chloride attach on

CS rebar, everything else is FRP/plastic, SS

hardware

• Sulfuric acid to pH control of 6.9-7.4, scale

inhibitor, TSS 10-50mg/l, sodium hypochlorite
9

Insights from Individual Facilities (cont.)

Brayton Point Station; Somerset, MA

• 1600 MW, 4 units

• Mount Hope Bay for cooling water

• Units 1-3 from Taunton River, Unit 4 from Lee River

• Enhanced Multi-Mode System

– Designed and proposed as part of NPDES renewal

– 20 cell, counter-flow, mechanical-draft cooling tower

– System allows for capture and removal of heat from

hottest water from any unit

– 33% reduction in cooling water withdrawal and heat load

– Reduced entrainment and impingement would reduce

adult equivalent fish losses by 40%
10

Aerial View of Brayton Point Station

Condenser Cooling Discharge

Taunton River Intake

Lee River Intake

Ref: http://www.epa.gov/waterscience/316b/symposium/proceedings.pdf
11

Existing Cooling System – Summer Operation

Unit 4

To Mount

Hope Bay

Taunton

River

Intake

Lee

River

Intake

Unit 3 Unit 2 Unit 1

Circulating Pump

Unit 4

To Mount

Hope Bay

Taunton

River

Intake

Lee

River

Intake

Unit 3 Unit 2 Unit 1

Circulating Pump

•June-September operation

•Max flow 1229 MGD

Ref: http://www.epa.gov/waterscience/316b/symposium/proceedings.pdf
12

Existing Cooling System – Winter Operation

Unit 4

To Mount

Hope Bay

Taunton

River

Intake

Lee River

Intake

(closed)

Unit 3 Unit 2 Unit 1

Circulating Pump

Unit 4

To Mount

Hope Bay

Taunton

River

Intake

Lee River

Intake

(closed)

Unit 3 Unit 2 Unit 1

Circulating Pump

•October-May operation

•Max flow 925 MGD (winter flounder spawning)

•Station operates “piggyback” mode – discharge from U1-U3

used as cooling water for U4

Ref: http://www.epa.gov/waterscience/316b/symposium/proceedings.pdf
13

Proposed EMM Operation – Unit 4 Closed Cycle

20-Cell

Cooling

Tower

To Mount

Hope

Bay Taunton

River

Intake

Tower

Intake

Recirculation of

Tower-cooled

Water

To Unit 4

Unit 4 Unit 3 Unit 2 Unit 1

Circulating Pump

20-Cell

Cooling

Tower

To Mount

Hope

Bay Taunton

River

Intake

Tower

Intake

Recirculation of

Tower-cooled

Water

To Unit 4

Unit 4 Unit 3 Unit 2 Unit 1

Circulating Pump

Ref: http://www.epa.gov/waterscience/316b/symposium/proceedings.pdf

•Used when Unit 4 operating at full load

•Unit 4 circ water pumps used to circulate CW to tower
14

Proposed EMM Operation – Unit 3 Closed Cycle

Ref: http://www.epa.gov/waterscience/316b/symposium/proceedings.pdf

•Used when Unit 4 is shut down

•Unit 3 circ water pumps shut down

•Cooling tower water recirculated to Unit 3 condenser
15

Proposed EMM Operation – Unit 4 Closed,

Unit 3 Partial-Closed Cycle

• Used when Unit 4 operating at less than full load

• CT water recirculated to both Units 3&4

• Unit 3 – one CW pump on, one CW pumps off

20-Cell

Cooling

Tower

To Mount

Hope

Bay

Taunton

River

Intake

Tower Intake

Recirculation of

Tower-cooled

Water

To Unit 4 To Unit 3

Unit 4 Unit 3 Unit 2 Unit 1

Circulating Pump

20-Cell

Cooling

Tower

To Mount

Hope

Bay

Taunton

River

Intake

Tower Intake

Recirculation of

Tower-cooled

Water

To Unit 4 To Unit 3

Unit 4 Unit 3 Unit 2 Unit 1

Circulating Pump

Ref: http://www.epa.gov/waterscience/316b/symposium/proceedings.pdf
16

Proposed EMM Operation – Unit 1&2 Helper Tower

• Used when Units 3&4 are off line

• CT acts as helper tower for Units 1&2

• Variable speed drives on Units 1&2

Ref: http://www.epa.gov/waterscience/316b/symposium/proceedings.pdf
17

Brayton Point EEM Performance Estimates

• Cooling tower, circ water modifications and modified

traveling screens (Units 1&2) estimated at $57.4M (2001)

• Annual maintenance cost of $240K

• Combined annual lost power generation – 97,900 MW-hr

– 72,600 for aux power, 25,300 efficiency penalties

• July 7, 2004 – EPA Region 1 decision to require EEM

• Current permit expired 1998

• Decision is under administrative appeal by plant owners