"Code of Practice on Safety in Nuclear Power Plant Siting" (HAF 101, hereinafter referred to as "the Code") has specified the minimum requirements for the safety of human induced events in relation to nuclear power plant siting. This Guide supplements the Codes by specifying several procedures, methods, data requirements and evaluations on certain design basis.
This is a guidance document. Methods and schemes different from those specified in this Guide may be adopted in actual practices, but it must be proven to national nuclear safety departments that they are equivalent in the aspect of safety level and do not pose additional risks to personnel in the plant as well as the public.
To guarantee that the nuclear power plant is safe enough, its design must meet the general rules specified in the Code and the "Safety Requirements for the Design of Nuclear Power Plant". One requirement to be complied with in the design, so as to meet those rules, is to determine the potential factors for human induced events within the area which may cause radiation of the nuclear power plant as well as the appropriate design basis preventing such radiation.
This Guide has concerned regional surveys and discussed hazardous phenomena in relation to the above mentioned human induced events. It has also outlined the process of initial siting as well as the information required to be obtained to determine the design basis events and to derive corresponding basis parameters.
During the nuclear power plant siting, fully consideration shall be given to rule out places with existing or foreseeable severe human induced events. For detailed description of the methods and procedures for the selection of plant site, refer to HAD 101/07, "Site Survey for Nuclear Power Plant".
As for the human induced events characterized as being random, probabilistic method shall be applied as long as adequate and appropriate data are available. In general, however, deterministic method, which is based on conservative and simple stipulations including restrictive physical factors, is preferred in the initial investigations. In some instances, it might be feasible that only one of the said methods is adopted.
A practical and feasible method to distinguish the potential external human induced events, among others, for which the determination of design basis parameters must be demanded is to go through a series of procedures, each includes the collecting of data as needed, until the potential factor can be proven not worthy of proper respect or the event impact evaluation can be proved accurate enough for the determination of design basis parameters. Therefore, this Guide describes the information necessary to be acquired and the judgment criteria for various events.
It is easier to identify the position of highly-hazardous facilities and the potential hazards, but shall also be considered in view of the impact of smaller activities which are likely lead to serious consequences. Such activities may only happen at specific locations under certain circumstances occasionally.
Plants sited differently are under different conditions, and the industrial, transportation and land using environment vary greatly throughout the country, thus it is impossible to provide a comprehensive and complete list for the potential sources of all human induced events. This Guide, however, provides and remarks a schedule of potential sources which are fairly common (see Table 1).
1 Introduction 1
2 Potential Sources of Human Induced Events and Their Features 3
2.1 General 3
2.2 Determination of Potential Sources 3
2.3 Effects and Associated Parameters 4
3 Data Collection and Evaluations 4
3.1 General 4
3.2 Data Evaluating Procedures 6
3.3 Sources Relevant to Industrial and Commercial Facilities 7
3.4 Sources Relevant to Transport 8
3.5 Source Display Map 8
4 Administrative Aspects 8
4.1 Control over Future Development of Activities Possibly Causing External Human Induced Events 8
4.2 Military Installations 9
5 Preliminary Screening and Detailed Evaluation 9
5.1 Preliminarily Screening and Evaluation 9
5.2 Detailed Evaluation 10
6 Aircraft Crashes 11
6.1 Preliminary Evaluation 11
6.2 Detailed Evaluation 11
6.3 Design Basis Aircraft Crash 12
6.4 Design Basis for Aircraft Crashes 12
7 Explosions 13
7.1 General 13
7.2 Stationary Sources of Explosions 14
7.3 Mobile Sources for Explosions 14
7.4 Design Basis Explosion 15
7.5 Design Basis for Explosions 15
8 Release of Hazardous Fluids 15
8.1 Fluids 16
8.2 Gas and Vapor Clouds 17
9 Other External Human Induced Events 20
9.1 General 20
9.2 Fires 21
Glossary 22
Annex I Aircraft Crashes 23
Annex II Explosions of Chemicals 30
Annex III Hazards of Drifting Clouds 34
Annex IV Fires 38
