Got Water?

David Lochbaum

Director, Nuclear Safety Project

June 29, 2012

Easy as 1 – 2 – 3

3

1

2

3 units of energy produced by the reactor

core yield 1 unit of electricity and 2 units of

waste heat (thermal pollution)

2 to Go

The waste

heat is

dissipated

into lots of

river, lake, or

ocean water.

Circulating Water System Modes

OPEN MODE

Circulating Water System Modes

HELPER MODE

Circulating Water System Modes

CLOSED MODE

Circulating Water System Modes

Cooling towers

reduce how much

water is drawn from

lakes, rivers, and

oceans by re-using

water.

Water is drawn to

replace water vapor

emitted from the

cooling towers.

There’s More

Nuclear plants also take water from the nearby

lake, river, or ocean and use it to cool

components and buildings.

This cooling system, commonly called the

Service Water system, supplies cooling water to

air conditioning units, lube oil coolers,

emergency diesel generator engine coolers,

spent fuel pool heat exchangers, and so on.

Intake

Intake

Plant Type

Total

Internal

CDF (mean)

SW CDF

Contribution

SW %

Contribution

Calvert Cliffs

1

PWR 1.3x10-4 1.4x10-5 11

Point Beach 1 PWR 1.4x10-4 2.6x10-5 19

Turkey Point 3 PWR 7.1x10-5 3.4x10-6 5

St. Lucie 1 PWR 1.4x10-5 1.8x10-6 13

ANO-1 PWR 8.8x10-5 1.1x10-5 12

Quad Cities 1 BWR 9.9x10-5 3.0x10-5 30

Cooper BWR 2.9x10-4 1.9x10-4 65

Surry 1 PWR 4.0x10-5 1.5x10-8 <1

Sequoyah 1 PWR 5.7x10-5 2.4x10-7 <1

Peach Bottom

2

BWR 4.5x10-6 1.4x10-6 22

Grand Gulf BWR 4.1x10-6 5.6x10-7 14

Table 4.8-1

Risk associated with Service Water (SW)

system problems can be high because of

the common mode factor – loss of cooling

provided by service water can disable

emergency systems and their backups.

Service Water Risk

07/2006 Calvert Cliffs 1

10/2008 Diablo Canyon 1

09/1993 St. Lucie 1

08/1984 St. Lucie 2

04/1994 Salem 1

06/1989 Salem 2

06/2004 San Onofre 304/2007 Salem 1

08/1970 Oyster Creek

06/2001 Point Beach 2

04/1976 Nine Mile Point 106/2001 Point Beach 2

04/2003 D C Cook 1&2

03/2006 FitzPatrick

02/2000 Ginna01/1996 Wolf Creek01/1982 Salem 201/1977 Salem 2

07/2007 Brunswick 101/1982 D C Cook 1&206/1972 Quad Cities 1

Which have caused problems?

Byron (2007): Corrosion (rust) thinned pipe wall until service water leak developed.

Location of leak

was just above

concrete floor

where service

water pipe rises

from underground

run and enters

safety-related

cooling tower

(part of Ultimate

Heat Sink).

XX

Non-safety related cooling

towers may be

unavailable, so safety-

related cooling towers

ensure adequate cooling for

Service Water.

Service Water system degradation

adversely affected safety-related

equipment at Indian Point Unit 2

(October 1980) and forced a shut down

with regulatory sanctions.

Containment cooling was provided by five Fan Cooler Units (FCUs).

Two headers provided Service Water to cool the FCUs

Common header routed Service Water from FCUs

There were leaks.

Lots of leaks.

Lots of time.

While the reactor operated, over 100,000

gallons of leaked water flooded the

containment and submerged the lower 9 feet of

the reactor vessel.

The NRC fined the company $210,000 in 1980.