atw Vol. 63 (2018) | Issue 2 ı February
The Application of Knowledge
Management and TRIZ for solving the
Safe Shutdown Capability in Case of Fire
Alarms in Nuclear Power Plants
Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin
1 Introduction The 2011 the Fukushima nuclear disaster in Japan was caused by a failure in the safe shutdown
system. The severing of power systems incapacitated several of the shutdown devices, thereby hindering the removal of
excess heat from the reactor. Under these conditions, zirconium on the protective cover of the fuel rods reacted with the
cooling water to produce hydrogen gas. The resulting explosion fractured the containment building, thereby allowing
the escape of radioactive materials into the surrounding environment.
Nuclear power plants designed in
the U.S. must conform to regulations
outlined by the Nuclear Regulatory
Commission (NRC). The safe shutdown
capabilities of a facility are
documented in the Final Safety
Analysis Report (FSAR), which must
be submitted to authorities prior to
the licensing of operations. Facility
upgrades are also subject to approval.
Operating specifications include
shut-down procedures to be implemented
in the event of an earthquake
or other environmental disaster. In
1979, the NRC proposed a number of
fire safety measures [10CFR50 App.R];
however, the complexity of nuclear
facilities has greatly hindered implementation
and enforcement. Nuclear
power plants are required to have two
independent safe shutdown systems,
either of which must be able to
manage plant operations during the
transition from operating phase to
cold shutdown. The simultaneous
failure of both of systems would lead
to a catastrophic collapse of the entire
system. This study sought to sought to
improve the safe shutdown performance
of nuclear power plants in the
event of fire. We compiled a wide
range of data pertaining to post-fire
safe shutdown of nuclear power
plants, while dealing with each system
and its components as discrete units.
Our main objectives were as follows:
1. To compile a knowledge base
of issues related to hazards in
nuclear power plants: The
knowledge base defines the safe
shutdown system used in each fire
zone, describes the components
used in each system, and organizes
the shutdown processes in the
form of a flowchart.
2. To assess the components of the
safe shutdown systems using the
Teoriya Resheniya Izobreatatelskih
Zadatch (TRIZ) method:
We defined the attributes and
parameters of various problems
associated with safe shutdown
equipment and developed models
for each individual problem using
TRIZ to identify feasible means of
improvement.
3. Improve the safety regulations
of nuclear power plants based
on case studies and a literature
review: We formulated a novel
approach to the analysis of case
studies with the aim of facilitating
the identification of omissions
and flaws in current evaluation
standards.
2 Literature review
Prior to 1974, there were only two
clauses in the national fire regulations
(U.S.): 10CFR50 Appendix A (fire
protection) General Design Criteria
(GDC) and R.G 1.70.4. In November
1975, after the fire at Browns Ferry
Nuclear Power Plant, the NRC
published the Standard Review Plan
9.5-1. In May 1976, the BTP APCSB
9.5-1App.A (Nuclear Power Plant
Fire Guidelines) came into effect for
nuclear power plants seeking to obtain
building permits after July 1 [NRC,
1976], 1976. In August 1977, the NRC
published the Generic Letter 77-02
[USNRC, 1977], addressing issues
pertaining to administration, the
regulation of organizations, firefighting
procedures, and quality
control measures. In 1980, the NRC
drew up 10CFR50 Appendix R (fire
protection program), detailing the
requirements of all nuclear power
plants that went into operation prior
to January 1st 1979. In February 1981,
the NRC announced 10CFR50.48
(fire protection) as the standing
regulations for nuclear power plant
fire safety [Information Notice, 1984].
Compliance with 10 CFR 50 App. R
was not mandatory for all nuclear
power plants operating before
January 1, 1979 (pre-1979 plants);
however, they had to follow the
basic design requirements. In contrast,
nuclear power plants operating
since January 1, 1979 (post-1979
plants) have had to comply with BTP
CMEB 9.5-1, Revision 2 [CRF, 1979]
In the case study of this paper, an
operating license was obtained for
reactor 1 on July 27, 1984. It should
therefore have been subject to BTP
CMEB 9.5-1 Rev.2 [July 1981]; however,
Section 9.5.1 of the FSAR from
the later Maanshan Nuclear Power
Plant refers to Appendix A to APCB
9.5-1 [NRC Branch Technical Position,
1981]. As a result, both were used
as references. Taiwan uses the fire
regulations of 10 CFR 50 Appendix R
as the basis for fire inspections;
however, these regulations are somewhat
rudimentary [TPC, 1999].
In U.S. federal regulations 10
CFR 50 Appendix A, General Design
Criterion 3 specifies the basic fire
protection requirements for nuclear
power plants [CFR, 2012]. For
example, the design of the fire protection
system must ensure that even in
the event of damage of improper use,
the safety performance would not be
impaired. Fire protection policy based
on defense-in-depth is used to protect
the shutdown system as follows:
1) preventing the occurrence of fires,
2) ensuring the rapid detection, control,
and extinguishing of fires that
do occur, and
3) ensuring the normal operation
of the safe shutdown system if a
fire cannot be extinguished [NCR,
1975].
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OPERATION AND NEW BUILD
Operation and New Build
The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin
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