atw 2018-02


atw Vol. 63 (2018) | Issue 2 ı February

Cable No.



SSD Equipment


| | Tab. 3.

Examples of post-fire safe shutdown cable paths.

After referring to the parameters

associated with post-fire safe shutdown

equipment in the previous step,

the fire-induced circuit-failure effect

parameters and wire/circuit attributes

were compiled into a post-fire

safe shutdown circuit analysis table.

Four types of parameter were

required: 1) fire-induced circuitfailure

equipment, 2) operating status

parameters, 3) fire-induced circuitfailure

parameters, and 4) wire/

circuit attribute parameters.

Step 3: The regulations stipulate

special requirements for the wiring

involved in hot shutdowns; therefore,

the scope of the core knowledge was

defined as the wires associated with

post-fire hot shutdowns.

Step 4: We establish an inventory

of the wires involved in post-fire safe

hot shutdown.

Phase 4: Establish a path associated

with post-fire hot shutdown for

use as a reference based on the special

requirements in APP.R with regard to

wires associated with hot shutdown.

Step 1: Define the scope of core

knowledge and the wires associated

with post-fire hot shutdown.

Step 2: Set the relevant wire/

circuit parameters, equipment operating

status parameters, equipment

attribute parameters, and safe shutdown

path parameters.

Step 3: Refer to the existing wire/

circuit layout program SETROUTE in

the original design to derive the circuit

layout. The fire zones will need to be

updated, as the original layout

program uses the old fire zones. To

facilitate analysis, the fire zones,

equipment specifications, safe shutdown

paths, and operating status

parameters must be added to the database

of the wire/circuit layout.

Step 4: Establish an inventory of

wire/circuit paths involved in post-fire

safe shutdown.

Step 5: Establish the post-fire

alarm safe hot shutdown path form

(Table 3). Compile a report of wire/

circuit paths involved in post-fire safe

hot shutdown. The nuclear power

plant in the case study has two power

units. Unit 1 contains 1,189 wires and

17,379 items, whereas Unit 2 contains



SSD Cable


1,184 wires and 17,233 items. Thus,

there are 2,373 wires associated with

post-fire safe hot shutdown. The

organization of the report is based on

the number system used for the safe

shutdown equipment, the attribute

categorization of the wires, their

origin and destination, the numbering

of the wire/circuit raceways, and the

fire zones through which they pass.

Phase 5: Construct the distribution

of post-fire safe hot shutdowns

throughout the entire plant.

Step 1: Define the scope of the core

knowledge and the post-fire safe hot

shutdown path.

Step 2: Set the fire zones to their

corresponding parameters.

Step 3: Based on the wire/circuit

layout program, identify the fire zones

through which each wire passes.

Step 4: Establish the distribution

of the post-fire hot-shutdown function

codes and replot the post-fire hotshutdown

tray routing diagram in

order to obtain an overview of the safe

hot shutdown capacity throughout

the entire plant.

Example: Series A is presented in

red and series B in green. The safe

shutdown cable path in the original

SETROUTE and corresponding function

code are used to obtain the safe

shutdown path and function code of

each fire containment zone (Table 4).

Phase 6: Establish a database of

items pertaining to basic fire prevention.

Basic fire prevention includes a

wide range of items: (1) basic data of

fire zones, (2) firefighting equipment

in fire zones, (3) fire dampers, (4) fire

doors, (5) combustion load of fire

zones, (6) list of fire zones adjacent to

each fire zone (7), inventory of heat

generated by all combustible items.

4.2 Application of TRIZ

The proposed knowledge management

approach revealed that fire

compartments 1 and 17 do not comply

with some regulations [10 CFR 50.48

APP.R]. Specifically, Wires involved in

post-fire safe hot shutdown must not

pass through the same fire compartment

without the implementation of

suitable fire protection measures. The

FROM No. Raceway No. FZ




FL FL No. HSD Path No. SSD Path

1 C101 D1 HSD-P1

1 C101 H1 HSD-P1

1 C101 I2 HSD-P2

1 C101 K2 HSD-P2

| | Tab. 4.

Example distribution list of fire alarm safe hot shutdown function codes.

| | Fig. 2.

Qualitative analysis model for identification

of problem.

| | Fig. 3.

Standard solutions for eliminating harmful

effects of fire.

passage of series A and B wires

through FZ 1 and FZ 17 renders this

area vulnerable to fire damage [Hua

and Yang, 2006]. The structure of this

problem is modeled in Figure 2.

Figure 3 presents a qualitative

field model illustrating the association

between completeness and damage,

revealing the first problems to be

eliminated or controlled in a standard


In this case, the designers used

XPE/Cl.S.PE cables with heat

resistance of 90 °C. Their Q value

(Bench-Scale HRR per Unit Floor

Area) is 204 kW/m 2 , which means

that they are classified as safe, even in


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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