Rod Group and Individual Control System - Nuclear Power Plant Instrumentation and Control Systems for Safety and Security - page 333

Figure 3. Structure of software-hardware complex SHC RG&IC-R for basic information and additional
functions

• Commands of emergency and preventative
protection (ERP, PRP1, PRP2) from one of
three independent channels of the irst and
second SHC E&PRP-R set;
• Commands of reactor power control, un-
loading, limitation and accelerated preven-
tive protection (RPwAR, RPwU, RAPP)
from one of three SHC RPwCUL&APP
independent channels;
• Commands and directions of manual (indi-
vidual and group) control initiated by the
operator via monitoring and control panel
in MCR (all elements of panel have sepa-
rate independent outputs for connection to
each channel);
• Data about vertical CR position in the core,
CR falls, duration of falling.
• Galvanic isolation of input circuits and
supply circuits, which receive each com-
mands, is provided.

tion - forms error signal and corrects unreliable
input information (also taking into account rules
of interpretation of possible malfunctions while
digital message transferring between channels, set
for different input signals. For example, absence of
data from any channel is interpreted as presence
in this channel of PRP1, PRP2, RPw U command,
absence of RPwAR command, etc.
On emergency reactor protection commands
received from the first and second SHC E&PRP
set, each signal forming cabinet forms control
signals and sends them to each power control
cabinet, where they initiate disconnecting of power
supply on direct and alternating current of CR
drives, which are controlled by this power control
cabinet. The same actions are activated by RAPP
signals which are formed in signal forming cabinet
by command of accelerated preventive reactor
protection, received from SHC RPwCUL&APP,
but they are transmitted only to power control
cabinets, which control the group of CR drives
previously selected for this command realization
(group selection is performed in signal forming
cabinet). Scheme of realization of commands of
emergency and accelerated preventive protection
is shown on Figure 4.

Each signal forming cabinet sends digital data
on condition of its inputs in two other channels
via fiber-optic communication lines, receives
from them similar data, performs data logical
processing, and in case of mismatching detec-