Writing the Case Study

DOE-STD-1058-93

Although the instructional developer should be concise, enough of a description is needed to

make the case meaningful. All aspects of the case related to the objective must be included.

In this example case study the specific points mentioned above are included in the following

excerpts.

DESCRIPTION

THE

supply and exhaust fans and will always

be toward the area of possible higher

EVENT

radiation. The reactor building and

refueling floor is the area of lowest

This commercial nuclear power

pressure. The standby gas-treatment

plant is a three-unit boiling water reactor

system must exhaust air from the reactor

site. At the time of the event, Units 1

building to maintain a negative pressure.

and 2 were in operation at 100% power.

In order not to exceed the capacity of

Unit 3 was under construction.

this system, inleakage to the reactor

building must be kept at a minimum.

Activities Preceding the Fire

The refueling floor is common for

The plant is designed so the air

all three reactor units. To maintain the

movement from one plant area to another

proper pressure....

is controlled by

...operation and also the potential

OR CORE SPRAY AUTOMATIC

personnel hazards associated with

B LO WD O WN

PERMISSIVE,""

fighting fires in electrical cabling with

REACTOR

WATER

LEVEL

water.

LOW-AUTOMATIC BLOWDOWN,"

and

"CORE

COOLING

Effects on Plant Operation

SYSTEM/DIESEL INITIATE."

The first indication of the fire's

The control room operators

effect on Unit 1 operation came

observed that normal conditions of

20 minutes after the fire started with

reactor water level, reactor steam pres-

the almost simultaneous annunciation

sure, and drywell atmosphere pressure

of several alarms:

"RESIDUAL

existed, so they were confused by the

HEAT REMOVAL

alarms. Over the next 8 minutes, several

events occured, including the....