Environmental Engineering Reference
In-Depth Information
•
Lifting and dropping with a working speed
of any (one) control rod.
tiating power supply dump from all drives
(by command ERP) or from preliminary
selected group of rods (by command APP).
•
Lifting and dropping with a working speed
of one (ifth) group of control rods.
•
To cabinets of control rod drives - signals,
which control transfer of a group of CRs
or an individual CR in manual mode (by
a command from a monitoring and control
board) or in an automatic mode (by com-
mands PRP1, PUL, APP, RPwC).
RG&ICS contains: sensors (S) of control rod
position; step electromagnetic control rod driv-
ers (A); software-hardware complex (SHC) with
a workstation WS and printer, placed in LOC;
device for selection, control and monitoring of
selected CR and selected group of CR (switches,
digital indication devices, mnemonic diagram
with built-in keys and panel computer), placed
in MCR; digital indication devices of all control
rods positions, placed in MCR and ECR.
Functions of group and individual control
command formation are performed by three in-
dependent interredundant channels. The central
part of each channel - signal forming (SF) device,
implemented in a separate cabinet.
Each channel receives:
•
To a monitoring and control board - infor-
mation on the position of all CRs by height
and mismatch of CR in each group and an
alarm message in case of exceeding an al-
lowable mismatch of at least of one group.
Direct control of position of each CR is ex-
ecuted individually by independent channels in
cabinets of control rod drives. Each channel:
• Receives control signals from cabinets
1SF, 2SF, 3SF initiated by commands ERP
and APP, and deenergizes electromagnets
of control rod drive after receiving signals
from, at least, of two cabinets.
• Receives digital messages from cabinets
1SF, 2SF, 3SF, processes received infor-
mation according to a logical condition
“two-out-of-three,” generates and outputs
a sequence of impulses to CR, causing its
lifting or dropping (or keeps CR still in
case of lack of commands for transfer of
this CR in message, received from, at least,
two SF).
• Stops outputting a sequence of impulses
after a controlled CR reaches the limit po-
sition (upper or lower).
• Automatically switches the control rod
drive to supply from a standby source in
case of disappearance of the main power
source or failures in control circuits.
• Commands of emergency reactor protec-
tion (ERP) and preventive reactor protec-
tion (PRP1, PRP2) from proper channels 1
ERPS and 2 ERPS.
• Commands of power unloading and
limitation (PUL), accelerated preven-
tive protection (APP) and reactor power
control (RPwC) from proper channels
RPwCUL&APPS.
• Group number CR, selected for manual
control, and commands of lifting or drop-
ping of a selected group.
•
Coordinates of CR, selected for manual
control, and commands of lifting and drop-
ping of a selected CR.
•
Information on position of all CRs by core
height, deenergization of electromagnets
(drop of CR) and duration of dropping in
the form of digital messages from position
control cabinets CR.
During a command activity PRP2, received
from 1 ERPS or 2 ERPS, output of signals for
upward transfer of CR is blocked.
•
To cabinets of control rod drives (not
shown in Figure 8) - control signals, ini-
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