atw 2018-02

atw Vol. 63 (2018) | Issue 2 ı February
OPERATION AND NEW BUILD 102
can be used for OMA for manual
disconnection or operations.
To prevent equipment malfunction
due to fire-induced cable damage, a
fire alarm in FZ 1W signals the control
room to initiate the first safe shutdown
path using Series A cables.
Similarly, a fire alarm in FZ 1E signals
the control room to initiate the second
safe shutdown path using Series B
cables. On-duty staff must take the
actions presented in Table 6.
FZ 17 contains mainly Series B
cables as well as 11 Series A cables.
The post-fire hot shutdown cable list
(Table 7) revealed there is no way to
re-route the cable paths. At this point
10b can be used for OMA for manual
disconnection or operations.
A fire alarm in FZ 17W signals the
control room to initiate the first safe
No.
| | Fig. 5.
Conformity to regulations in chart form.
No. Cable No. SSD
Code
SSD
Equipment No.
Status
1 B-EF-HV203 ON
2 B-EF-HV206 ON
3 B-EF-HV221 ON
4 B-EF-HV222 OFF
5 B-EF-HV230 OFF
| | Tab. 8.
Valve states in hot shutdown mode.
Cable
Code
SSD Equipment
No.
SSD
Path
shutdown path using Series A cables.
A fire alarm in FZ 17E signals the
control room to initiate the second
safe shutdown path using B cables.
On-duty staff must take the actions
presented in Table 8.
The application of TRIZ requires
that the following conditions be
satisfied: At least one of the wire series
has avoided fire damage. For the sake
of simplicity, we adopted two inventive
principles: finding local properties
and taking preliminary actions.
Nuclear power regulation 10 CFR
50.48 APP.R stipulates that any wiring
essential to post-fire hot shutdowns
that passes through the same fire zone
require sufficient shielding to protect
them from fire for at least three h.
They must also be separated at least
20 ft, and automatic fire detection
and extinguishing systems must be
installed in the fire zone in question.
All wiring is expected to comply
with these regulations; however, prior
to modifications based on the proposed
method, 22 of the wires in
Series B were non-compliant. This
situation could not be foreseen without
integration of 850,000 pieces of
path data via knowledge management.
Among the 22 wires, 11 were
re-laid and within a fire compartment,
thereby reducing the number of
non-compliant wires to 11. According
to the principle of preliminary action,
the remaining 11 wires were deemed
not to affect post-fire hot shutdown
performance; therefore, even these 11
wires can be said to comply with
regulations.
Regulations stipulate that the
control room or emergency control
station be equipped with a series of
hot shutdown systems capable of
maintaining hot shutdown conditions
in the event of a fire in Fire Zones 1
and/or 17.
SSD
Cable Type
Raceway
No.
1 B1EEFHBCBSB H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE
2 B1EEFHBCBSD H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE
3 B1EEFHBCBSE H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE
4 B1EEFHBCJSA H2 C77 B-EF-HV206 HSD-P2 HSD-S B1EZJF4TPBA SE
5 B1EEFHCC8SA H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE
6 B1EEFHCC8SB H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE
7 B1EEFHCC8SC H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE
8 B1EEFHCC9SA H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE
9 B1EEFHCC9SB H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE
10 B1EEFHCC9SC H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE
11 B1EEFHCCASA H2 C77 B-EF-HV221 HSD-P2 HSD-S B1EZJF4TPBA SE
| | Tab. 7.
Series A cables in fire compartment 17 for safe hot shutdown.
Rway
Code
Fire compartments capable of
withstanding fire for three hours were
installed between post-fire safe hot
shutdown wires. The wires were
horizontally separated by at least 20 ft
and automatic fire detection and
extinguishing systems were installed.
Following these improvements in Fire
Zones 1 and 17, the post-fire safe hot
shutdown wires were in full compliance
with regulations (Figure 5).
Number of cables that do not
comply with regulations ≠ Estimated
number of cables that do not comply
with regulations = “Do not comply
with regulations”
Number of cables that do not
comply with regulations = Estimated
number of cables that do not comply
with regulations = “Comply with
regulations”
Number of non-complaint cables in
case study nuclear power plant = 0
5 Conclusions
This study applied TRIZ and
knowledge management to an actual
nuclear power plant in order to
bring the facility up to regulatory
minimums. Problems were identified
using hierarchy analysis in conjunction
with knowledge management for
the construction of a database. We
then identified elements that failed to
meet current regulations. TRIZ was
used to identify optimal solutions in
order to minimize the costs involved
in making improvements to existing
nuclear power plants.
The database of wires and circuits
essential to post-fire safe shutdown
operations enables operators to
identify affected systems and decide
whether immediate isolation is
required. The implementation of fire
zones makes it easy to determine
whether a zone lies along a safe
shutdown path. The proposed method
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