Chapter 9 Siting

1. Site Assessment

   1. Site Conditions

In planning a NPP, the first matter of importance is selecting a suitable construction site.

The conditions necessary for NPP siting are similar to those for conventional fossil power stations, with one major difference, necessary safety measures for the public near the plant site must be fulfilled against the release of radioactive material in the event of an accident in the plant. In Japan, in order to protect the public from such danger the "Regulatory Guide for Reviewing Nuclear Reactor Siting Evaluation and Application Criteria” ⁰ establishes necessary conditions for NPP siting. In the Safety Review, acceptability of the proposed nuclear plant site is reviewed in accordance with the guide. Hie contents of the guide are discussed in Section 9.2.1.

Typical appropriate and desirable site conditions including those to meet the site review guide are listed below.

1. Availability of a sufficient area for siting. This is to secure sufficient land area surrounding the NPP so that the radioactivity level at the site boundary remains within the established limit during the normal operation and in the event of accident It must also be located conveniently from the viewpoint of the construction work.

2. Consideration of population density. The proposed site must have a low population density in the region adjacent to it and it must be far from high population centers.

3. No recorded severe damage due to natural causes at or near the site in the past and not likely in the future.

4. Availability of sufficient sub-ground geological structure to support building foundations from the viewpoint of seismic capability.

5. Availability of sufficient water sources for

condenser cooling and utility water.

(0Feasibility of constructing harbor facilities for shipping of heavy equipment and nuclear fuel as well as access roads for ground transportation.

2. Procedures for Site Assessment

After a preliminary site assessment by the electric utility and in preparation for the construction, the procedures shown in Figure 9.1.1 are necessary.

Major points of the procedures are discussed below:

1. Environmental impact assessment

With respect to the environmental impact of the proposed power station, general rules are provided in the Law for Environmental Impact Assessment. The Electric Utility Industry Law prescribes other regulations unique to power stations.

The environmental impact assessment predicts and evaluates the impacts of the power station to the environment during its construction, maintenance and operation through investigation of the proposed site and its surroundings and establishes measures to preserve the environment. The assessment involves hearings for the prefectural governors and general public as well as evaluation by the National Government.

2. Preliminary public hearing

With respect to various problems associated with the NPP siting, a series of preliminary public hearings is held in order to gain understanding of the local public and to reflect their opinions and wishes to the related public administration. The preliminary public hearing is held under the sponsorship of METI and the electric utility provides the presentation. This sort of public hearing activity is unique to NPPs.

The public hearing held during the Safety Review under the sponsorship of Nuclear Safety

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Regulatory authority

Electric utility

] Development Area (Minister of METI)

: notification

Prefectural governor hearing <

Figure 9.1.1 Procedures related to site assessment

Commission is a separate activity and it is called the Secondary Public Hearing.

3. Designation of important electric power development area

The designation Important Electric Power Development Area is given by the Minister of METI on the prior application of the electric utility in order to pave the way to secure development of important electric power generation resources. Having such a designation is expected to facilitate smooth local acceptance and licensing activities by related governmental offices.

2. Basic Philosophy of Site Safety

   1. Site Review Procedures and Contents

At the time of application for a license to establish a reactor, the Safety Review is conducted under the organization and the procedure as described in Chapter 1. At that time, suitability of the proposed site is reviewed making due consideration for location, earthquake, geology, meteorology,

hydrology and social environment. Furthermore, the review focuses on acceptability of the following three site review guidelines;

1. Establishment of a non-residential area around the reactor up to a certain distance and assurance that no one will live within that area in principle. The target radiation dose to determine the distance is such that at the periphery of the boundary of such an area, the whole-body radiation dose of 0.25 Sv or thyroid exposure dose (child) of 1.5 Sv must not be exceeded in the event of a major accident

2. Establishment of a low population zone outside of the non-residential area such that the target radiation dose at the periphery of this low population density zone, i.e. the whole-body radiation dose of 0.25 Sv or thyroid exposure dose (adult) of 3 Sv, is not be exceeded in the event of a hypothetical accident.

3. Still further, the site is separated by a specified distance from the high density population zone, the reference dose of which is 20,000 man-SV as a target

These guidelines, however, are subject to re­

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