30 Sep 94
B-3. Identification of Systems Critical to
Operation and to Emergency Response after
a Damaging Earthquake
(6) Radio system for offsite communications.
a. The mix, configuration, and operation of the
(7) Sump pumps.
numerous systems necessary to operate and control
dam facilities are unique to each dam. It will be
(8) Normal house power.
necessary for a systems engineer intimately familiar
with a facility to determine which systems can
(9) Power switchyard equipment including
adversely impact safe shutdown or operation. It is
important that this evaluation be made with the
understanding that operation of any one system must
(10) General equipment.
be evaluated when several other systems (or any mix
of systems) may be inoperative or malfunctioning at
(11) Generator thrust bearing lubrication system.
the same time. This is not an easy task because of
the large number of systems involved, and the fact
(12) Generator bearing lubrication oil cooling
that interactions and interdependencies may not be
well understood. Because of the rarity of dams being
subjected to damaging earthquakes, there is little
experience of how a dam's system will respond.
maintain computers or communication systems.
Also, because of their rarity, emergency response
planning seldom takes into account the special prob-
(14) Computer systems.
lems introduced by earthquakes.
earthquake and identifying the systems that might be
needed to respond, it should be assumed that the dam
(16) Internal telephone system.
will be separated from the power grid because of
problems with the power transmission network.
Special consideration should be given to the interac-
tion of dam facilities. Some interactions may not be
well understood or may be hidden. A common
(18) Miscellaneous systems.
example is power to critical components of a system
that were added or modified after the initial construc-
tion in which the item was inadvertently connected to
regular power circuits rather than to circuits provided
(b) Critical access roads.
with emergency power. Another example would be
waterlines outside of the dam that have branches that
(c) Suspended ceilings in control rooms.
are not well documented. A failure in one of these
lines may depressurize and drain the system.
c. Several of the systems that may be critical
for the safe shutdown of the facility or its continued
measures for each of the above systems will be dis-
operation are listed below:
cussed in one of the two following sections. The
next section discusses systems required for dam pro-
(1) Emergency batteries and emergency power
tection or the safe shutdown of dam operations. The
for monitoring, control, and other systems.
subsequent section describes systems needed for
continued operation of the dam. For a particular
(2) Spillway control systems.
facility some of these systems may be shifted
between these two sections. For the configuration of
(3) Wicket gate governor systems.
some facilities, there may be other systems that are
not listed here that should be considered for the