closure project manager - Document Request - U.S. Department of ...

2.3.1.6 Smoke Detection System
Buildings 996, 997, and 999 (including Corridors B and C) are provided with Pyrotronics
high-voltage DC ionization smoke detectors (a smoke detection system is not required per
NFPA 101 for these buildings and corridors). An ionization smoke detector has a small amount
of radioactive material that ionizes the air in the sensing chamber, rendering the air conductive
and permitting a current flow through the air between two charged electrodes. This gives the
sensing chamber an effective electrical conductance. When smoke particles enter the ionization
area, they decrease the conductance of the air by attaching themselves to the ions, causing a
reduction in ion mobility. When the conductance is below a predetermined level, the detector
responds. A signal from the detector is transmitted to the alarm panel in Room402 of
Building 991. The signal transmitted from the smoke detector is used to notify the CAS and the
FDC and to activate an alarm in the alarm panel. A frre annunciator panel is located in the office
area of Building 991 for the smoke detection system. This panel receives a signal when the
smoke detector is initiated and is used by the Fire Department to see where the fire is located in
Buildings 996, 997, and 999.
The detectors receive power from the electrical power system through the fire panel. The
fKe.panel circuitry is supervised. A trouble signal is received at the FDC when AC or DC power
to the panel is lost. The Pyrotronics smoke detectors have approximately 24 hours of battery
capacity. The smoke detectors are tested periodically by the Fire Department to be sure they
will function in an emergency.
e 2.3.1.7 Fire Phones
Fire phones are located throughout the Building 991 Complex as shown in Figures 2-6
through 2-8. Fire phones are not a detection system, however, fire phones allow building
personnel to sound a local fre alarm and transmit an alarm to the CAS and the FDC when fire or
other abnormal conditions exist with the building.
When the fire phone receiver is lifted, a signal is sent to the local bell panel, which
activates the building fire bells. The bell panel receives power from the electrical power system
and is also supplied with batteries that provide a secondary power supply. A separate signal is
sent via the SI0 panel to the CAS and to the FDC. If personnel are unable to stay at the phone,
a distinct alarm point at the CAS and the FDC identifies the location of the phone.
2.3.1.8 Fire Extinguishers
Fire extinguishers are located throughout the Building 991 Complex as shown in
Figures 2-6 through 2-9. The fire extinguishers are either dry chemical or liquefied gas and are
rated for Class ABC fires.
Revision ,I-
Building 99.1 Complex FSAR
Seplernher 1993 I