Environmental Engineering Reference
In-Depth Information
station and MCR gives the corresponding alarm
message which form and content allow to quickly
and accurately detect the place, time, character
and hazard level of the failure. The message is
comes with audio signal. Display of unreliable
data detected during the input signals diagnosis
is accompanied by clearly distinguishable and
uniquely understandable marker. The required
diagnostic depth (to changeable component parts
in each operating stand-alone unit) is provided by
built-in diagnostic means.
The input and output signals of SHC E&PRP
are shown at Figure 4, place SHC E&PRP in re-
actor control & protection systems - at Figure 5.
Software
has multi-component structure and
consists of system and application software.
System software
includes operational and sup-
porting software. Operational software contains
means, which the application programs call appeal
directly. Supporting software (tools) is used for
development of application software, debugging
and testing of SHC E&PRP and its component
parts at the operation location.
The main functions are performed by the
complex programmable electronic components
(FPGA).
A
pplication software
has a two-level struc-
ture. Low-level software provides activity of the
functional and communication processors built in
blocks of temperature sensors signal input, analog
and discrete information input, USB-OPTO inter-
face adapters, functional and set-point processors
in the protection signal forming blocks.
At the low-level of application software the
following software tools are used:
The adopted by developers strategy of data
processing task distribution among many low-level
microcomputers, absence of direct connections
between the performed calculation processes,
as well as abandoning of program methods for
performing of the most complex functions the
performance of which is transferred into FPGA,
allowed to simplify the structure and to reduce
software volume. It resulted in decrease of er-
ror possibility which cannot be detected during
software verification (and risk of common cause
failures which could be caused by such errors).
External appearance of software-hardware
complex SHC E&PRP are shown at Figure 6.
SAFETY ASSURANCE
SHC E&PRP belongs to the elements of safety
control systems, that is why all the applied funda-
mental and technical safety principles regimented
for such elements in Ukrainian regulatory docu-
ments and international standards are realized in it.
SHC E&PRP functions required for NPP
safety assurance are performed in any initiating
event and failure of one of the elements which is
independent of the initiating event (
single failure
principle
). The requirement for survival in any
type of failures, as well as in case when the fail-
ure of one elements causes failures affected by
it, is regarded. The possibility of hidden failure
is additionally regarded. SHC E&PRP structure
allows to save survival in case of failure of any
quantity of elements in one channel of the first
and / or second set, as well as in case of several
different elements failure in two or three channels
in each set.
In SHC E&PRP the
redundancy principle
is
observance: each set has the independent protec-
tion channels on each of the parameters which
characterize limits and / or safety performance con-
ditions. Redundancy is one of the main structural
SHC E&PRP features. In the redundant channels
of each set the three-step feature based redundancy
is applied. Redundancy of primary and secondary
•
FPGA electronic designs performing pro-
tection functions;
•
Processor software by Texas Instruments
company, developed on Assembler pro-
gramming language;
•
Software developed on С programming
language for Altera Nios process emulator
implemented into FPGA Cyclone logical
structure.
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