International Standard Bases and Safety Classification - Nuclear Power Plant Instrumentation and Control Systems for Safety and Security - page 36

another number INSAG-12 (IAEA, 1999,a). The
document contains objectives and fundamental
principles of safety assurance.
Documents in IAEA Safety Report series -SRS
contain papers made by of a group of experts,
representing information publications without
setting requirements. These publications describe
practical experience, give practical examples and
detail methods, used to achieve safety require-
ments compliance.
In IAEA Technical Report Series -TRS let us
note a NPP I&C reference book (IAEA, 1999,
b) prepared by a group of authors from different
countries. A significant part of the topic is occupied
by a description of NPP I&C in Finland (Loviisa),
France (series Nº4), Great Britain (Sizewell B),
Canada (CANDU, series 6), Russia (WWER-
1000), USA and others. .Another example of a
document of this series is a report on verification
and validation of I&C software (IAEA, 1999, c).
A significant number of documents, related
to NPP I&C, was issued in “ TECDOC ” series.
These documents are generally devoted to specific
tasks and summarize experience of IAEA member
countries. The following issues are considered:

operating and licensing aspects, tests and also
examples of I&C modernization in different coun-
tries - Hungary, German, Korea, Russia, USA,
Finland, Czech Republic, Ukraine.
In the development of TECDOC documents a
significant role was played by the Technical Work-
ing Group on NPP Instrumentation and Control,
uniting experts from a number of countries. This
group was created in 1970. The main objective of
the Working Group is to promote the exchange of
information on NPP I&C and to stimulate and, if
possible, coordinate research in this field of NPP
I&C in interested Member States and international
organizations. The scope of work covers all aspects
of the life cycle of I&C systems and equipment
from feasibility study and design through instal-
lation, commissioning and licensing to operation,
maintenance and decommissioning. The work thus
not only covers technical details of the technology
but also the management processes by which it
is to be developed, designed, licensed, quali-
fied installed, and maintained. In 2011 a report
(IAEA, 2011,a) was prepared by the experts of
this group, which is an introductory description of
I&C systems and their life cycle. It compiles the
necessary basic information to understand I&C
systems in NPPs, an explanation of the significant
role of I&C systems in maintaining and improving
safety, plant performance, and economic.

• Modernization and new technologies, in-
cluding: software issues (quality assur-
ance, veriication and validation, life cycle
management and others); digital hardware
(reliability, safety analysis, I&C computer-
ized hardware and others).
• Ageing and operating experience.
• Human factor, including operator support
systems, man-machine interface, simula-
tors and others.

IAEA SAFETY CLASSIFICATION
PRINCIPLES

Safety class is an attribute that is taken into
account by hardware and software developers,
system designers, operating organization, other
participants in I&C creation (modernization),
nuclear regulatory authorities. One follows safety
class in setting requirements on I&C systems
and their components, developing, producing,
product testing, designing, checking and provid-
ing maintenance, and also during assessment of
their compliance with regulatory requirements.

An example of document in ТЕСDOC series is
IAEA-TECDOC-1016 “Modernization of instru-
mentation and control in nuclear power plants”
(IAEA 1998), issued under the guidance of W.
Bastl (Germany) and J. Naser (USA). It contains
information about management of modernization,
design criteria, requirements and restrictions,