locations is available for disassembly, checking and servicing with provisions for monorails and chain blocks for lifting. Due consideration is necessary for transportation of this equipment by providing a shielding wall with partially removable block masonry from the passage to the equipment access hatch. Among the turbine auxiliary apparatuses the moisture separator is large and heavy and should be located nearest to the main turbine. Its location will be either on the turbine building operating floor or under it depending on the arrangement of the feed water heaters and the turbine building size optimization.

In the turbine building, it is also necessary to install a noble gas hold-up system for the radioactive noble gases that are extracted from the condensate and to decay its radioactivity. This system is normally placed near the condensers. In order to avoid excessive volume addition to the turbine building, a separate common building for two units may be allocated for the noble gas hold-up system, but it is most advantageous to locate the system within the turbine building in order to minimize the length of highly radioactive piping.

This is the basic equipment arrangement for the reactor building and the turbine building. The recent trend has been to automate the equipment for outage and maintenance and their optimum arrangement has become more important. Furthermore, since building design and construction has been optimized by adopting large-scale prefabrication of piping and block constructions using heavy lifting devices, equipment arrangement must be in harmony with such advanced building design and construction methods.

2. Main control room (Control building)

The control panels for the NPP are concentrated in the main control room. Therefore, the operating personnel must be able to stay in the control room in an unlikely event of an accident without excessive radiation exposure and must be able to perform necessary actions to counter the accident For such purposes, the main control room must be located within a seismically capable building, and be located with good accessibility, close to both reactor and turbine buildings.

The location of the main control room depends on various factors including the size and shape of the reactor building and its adjacent buildings and accessibility, and it may be located in the corner of a reactor building, located in a auxiliary building together with radioactive waste treatment system, or as an independent building. When the control room is in a separate control building, it is usually a reinforced concrete structure and is serving as a common building for two reactor units and also containing a cable spreading room and a switchgear room.

2. Radioactive waste treatment facility building

This building houses the treatment system for liquid and solid radioactive wastes generated in the reactor and turbine buildings. Although it is possible to incorporate this building in a combined structure with the reactor building, the recent trend has been to locate only the waste storage tanks in the combined structure and to process the waste from multiple units in a common waste process facility.

Because of the fact that the treatment system deals with radioactive material, the tanks and the processing facilities are installed in rooms separated by shield walls and their control panels and cable spreading room are located within the treatment facility building. Due to the large storage and collecting capacity required, steel lined shield concrete structures may be utilized in order to decrease the building volume.

2. Service building

The service building houses the radiation control and management facility for the plant personnel entering and exiting from controlled areas of the reactor building and turbine building. In order to provide good accessibility to those buildings, the service building is either located near the reactor building and the turbine building as an independent separate building, or it is located within the turbine building or the control building. The service building contains the entrance/exit control system, locker rooms, shower room and a chemical laboratory. In a multi-unit plant, it is often made as a common facility for two units.

2. Exhaust stack

NSRA, Japan

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