Safety-grade
Programmable
Logic
Controller
By Dong-Young Lee and Kee-Choon
Kwon, Korea Atomic Energy Research
Institute.
Dong-Young Lee
Dong-Young Lee received the B.S. and
M.S. degree in Electrical Engineering
from the Kyungpook
National University
in 1984 and 1987
respectively, and
Ph.D. degree from the
Chungnam National
University in 2005. He
has been a researcher
of the Korea Atomic
Energy Research
Institute since
1987. His research
interests include
instrumentation
and control system,
reliability analysis,
and safety assessment.
Summary
Korea developed a Programmable
Logic Controller (PLC) for a digital
safety system for the APR1400. With
the safety-grade platform PLC, a reactor
protection system, an engineered safety
feature-component control system, and
a reactor core protection system were
developed, and applied to Shin-Hanul
units 1&2.
POSAFE-Q PLC
The safety-grade PLC platform
named POSAFE-Q was developed so that
it meets the requirements of the Class 1E,
10 CFR 50 Appendix B, , and Seismic
Category I.
The PLC consists
of various modules
such as a power mod-
ule, a processor mod-
ule,
communication
modules, digital input/
output modules, analog
input/output modules,
a local bus extension
module, and a high-
speed pulse counter
module. The PLC in-
stalls two independent
power modules in a
rack. The power mod-
ule has a 100% power
supply capability for each. Accordingly,
even when there is a fault in one power
module, it does not affect the PLC op-
eration. The PLC can extend the number
of input/output modules through a local
bus extension module. The communica-
tion modules consist of Profibus-Fieldbus
Message Specification (FMS), High Reli-
ability-Safety Data Link (HR-SDL), and
High Reliability-Safety Data Network
(HR-SDN).
The processor module uses a Texas
Instrument Digital Signal Processing
(DSP) CPU and the real-time operating
system named pCOS was developed
based on the Micro-C real-time operating
system. All communication modules
were developed based on the Field-
bus protocol to meet the deterministic
requirements.
The engineering tool named pSET
was also developed. The developers of
the application programs can perform
programming, debugging, and simulation
on the pSET environment. The application
program developed on the pSET is
downloaded into the processor module
through RS-232C. The pSET operates on
Windows 2000/NT, which meets the IEC
61131-3 requirements.
Equipment
Qualification
(EQ)
including environmental qualification,
seismic qualification and EMI/EMC
qualification have been performed
according to EQ code and standards. Total
man-machine interface system including
safety-grade PLC based digital reactor
protection system is determined by
Korean utility and vendor organizations
to apply to Shin-Hanul units 1&2, with
a commercial operation date of 2017 and
2018 respectively.
The digital safety system is the plant
protection system including Reactor
Protection System (RPS), Engineered
POSAFE-Q PLC Digital reactor protection system.
44
NuclearPlantJournal.com Nuclear Plant Journal, May-June 2014
