Plant
Process
Computer
Systems
By Don Chase, Scientech.
Don Chase
Don Chase has been involved in the
nuclear power industry for 40 years.
During the late 1970s and throughout
the 1980s he was
directly involved
in the concept
and design of the
GEPAC ANDS4800
and ANDS5500
products at Analogic
Corporation. He
worked with both
GE and their
customers to the
implement of
these products.
Throughout the
1990s thru 2004
he worked for RTP
and managed the
implementation
of the RTP7400,
RTP2000, RTP2300 and RTP3000
products in the nuclear market. Over
the past nine years Don has been
responsible for Scientech’s efforts in the
nuclear Plant Process Systems market.
Don is known to and has worked with
virtually every Plant Process Computer
group in the US nuclear market. He has
been the technical liaison for more than
sixty Plant Process Computer projects.
Chase has an Associate of Science from
North Shore Community College and
a Bachelor of Science from Eastern
Nazarene College.
The largest single contributor to
the fragility of nuclear industry Plant
Process Computers (PPCs) today is
the remarkable ability of plant staff to
repeatedly find temporary solutions to the
endemic issues they encounter in these
aging systems. The ability of plant staff
to remedy issues and the plants’ ability to
temporarily sustain operation without the
PPC are the main reasons that many PPCs
across the industry are unreliable.
Overview
Plant Process Computers have been
in use and evolving since 1960. The design
basis for these systems has expanded
to fit plant operating requirements
continuously since they were introduced.
Attempts to standardize
the nuclear PPC
essentially ceased
at the point where
the initial plant
construction cycle
ended, circa 1985.
U n f o r t u n a t e l y ,
maintaining a strict
design basis for the
system was never
a priority and has
resulted in poorly
documented systems
defined by wants and
desires as opposed to
a rigorously imposed
set of requirements.
While originally not
critical to safe and efficient operation of
the plant, the PPC now is.
Current PPC functionality is the
outcome of ad hoc requirements to
monitor operating conditions in the plant
that must be synthesized from available
process variables and I&C design goals
to minimize the control room size,
complexity and cost while maximizing
the information available to the operator.
Various NRC, EPRI and INPO initiatives
have addressed the core functionality
issues but have failed to codify specific
requirements for the PPC.
Early plant computers performed
thermal performance calculations and
limited data logging. Today’s plant
computers include a broad set of real
time applications ranging from thermal
performance to rodposition, annunciation,
rod movement control, power density,
meteorological
monitoring,
Safety
Parameter Display, radiation monitoring
and many more. This expansion and
increasedsophisticationwill continueover
the next decades to include applications
supporting system analytics and a variety
operator support tools that will enable
enhanced plant safety and performance.
Substantial expansion of plant operating
information to all plant disciplines will
enable significant reductions in operating
costs, outage duration, unplanned outages
and increased capacity factors.
Some utilities, recognizing the
advantages of a fully operational and
robust PPC, have begun strategic
programs to implement a reliable and
renewable PPC design that is expected
to remain technologically “current”
and in service for the plant’s remaining
operational life and decommissioning
period. This new approach to managing
the PPC is called “Refresh”. It is the
antithesis of the complete “forklift”
replacements performed in the past.
As the name Refresh reflects, it is a
plan to update, at appropriate intervals
with minimal modification impact, key
system components that will over time
compromise system performance.
In addition to significantly improved
reliability and availability, the Refresh
strategy has demonstrated the ability
to save in excess of $5 million in 2015
dollars per unit over the remaining
operational life (~20 yrs.) of each unit
where it is implemented.
Stated simply, the strategy replaces
software
and
processor-dependent
components every seven to ten years
and Input/Output hardware every other
refresh cycle.
Yesterday’s PPC
The systems and equipment in
service today are literally spread over
the entire hardware and software product
spectrum, many comprised of late1970s
technology. Computing hardware ranges
from second generation minicomputers
to the latest server-based environments.
Operating system platforms still
include one or two proprietary designs,
many UNIX and VMS systems with
the balance using various versions of
Microsoft Windows ranging from NT
to Server 2012. Software applications
are written in assembler code, COBOL,
The full unabridged version of this paper
is available by contacting the author at
28
NuclearPlantJournal.com Nuclear Plant Journal, March-April 2015
