Figure 2.11.6 Outline of hvac system of the turbine building

filter

exhaust fan

Figure 2.11.7 Outline of hvac system of the main control room

5. Fire Protection System

The fire protection system is similar to that of ordinary buildings on the plant site and it meets fire safety and prevention laws. An outline of the fire protection system is shown in Figure 2.11.8.

50. Key equipment

The fire protection system is as follows.

1. Fire extinguishers and indoor/outdoor fire hydrants.

2. Non flammable gas fire protection system.

3. Foam extinguishing system.

The fire extinguishers and fire hydrants are installed in all areas in buildings for primary fire fighting. The water of the fire hydrants is supplied from the fire pump connected to the filtered water

storage tank. A non flammable gas fire protection system (normally carbon dioxide gas is used) is installed in storage or management areas inside the buildings with large amounts of combustibles. These areas are the emergency diesel generator room, turbine oil tank room, and cable handling room. The foam extinguishing system is installed in storage areas outside the buildings for large amounts of combustibles; these areas include the heavy oil tank and the light oil tank.

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Figure 2.11.8 Outline of the fire protection system

12. Advanced bwr (abwr)

1. Design Principles

The ABWR is a plant concept identified in the Improvement and Standardization Program, Phase III, by the initiative of the then Ministry of International Trade and Industry (MITI) of the Japanese Government. The development was completed in 1986 and its first unit, the Kashiwazaki Kariwa Nuclear Power Plant Unit

No. 6, started its commercial operation in 1996.

The ABWR has been developed to achieve the following goals:

1. Enhanced safety and reliability;

2. Enhanced operability and maneuverability;

3. Less occupational radiation exposure;

4. Reduced amount of radioactive waste; and

5. Improved economy.

To achieve these goals, various characteristic technologies have been developed for design. The basic concepts of each feature are described below.

1. Enhanced safety and reliability

2. Hie use of reactor internal pumps (RIPs) has eliminated the external recirculation loop piping and simplified the piping system composing the reactor coolant boundary. Consequently, the design capacity of the ECCS could be reduced with no need to assume large- diameter pipe breaks. Furthermore, the core can always be kept covered by water even if a single failure of the ECCS is assumed.

3. The ECCS redundancy has been strengthened by the three independent divisions of high and low pressure systems in a pair, improved from the conventional one division high pressure system and two division low pressure systems.

4. The adoption of the RIPs has eliminated the external recirculation pumps and the piping, and consequently reduced the size of the PCV in the conventional BWR. The external recirculation pumps and the piping had to be located under the RPV for securing the necessary net positive suction head (NPSH). But, by dispensing with external loops and piping, it became possible to integrate the cylindrical RCCV with the reactor

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