Over the past several decades the IAEA has utilized the technical expertise of its member states to formulate and publish standards related to all aspects of nuclear reactor safety. These standards can be used immediately by the regulatory authorities of member states, to establish their own unique safety regulations as befit their unique circumstances and to incorporate these regulations, as desired, into their national governance structure.

The standards and guides developed by the IAEA have been augmented over the years by the work and publications of the International Nuclear Safety Advisory Group, appointed by the Agency’s Director General.

Because of their concise format and their high standard of intellectual integrity, this summary of the international safety regime uses these INSAG documents as the primary source of guidance to new plant users.

The world inventory of available published literature already contains much of the history and technology of the nuclear energy enterprise over the past 60 years. Many conference proceedings, reports and textbooks are freely available in libraries, a few of which are listed here. Naturally, some information is restricted for reasons of commercial interest.

10.8.1 Owners’ groups

Owners’ groups mentioned in Section 10.6.1 are sharply focused on sustain­ing good performance of their own power plants. These groups encourage joint R&D and education of operating staff. For example, the CANDU group website can be found at COG (2010). Generally, this site offers infor­mation to the owners of CANDU power plants; other examples are AREVA-NP (2010), General Electric (2010), and the Westinghouse Owners’ Group (WOG; unfortunately, no reference available). One general charac­teristic of these groups is that they maintain all or some of their information confidential to group members. This is understandable due to the large commercial interests involved.

E. GIL LOPEZ, IAEA Radiation Safety Regulator, Austria

Abstract: Despite nuclear facilities being designed, constructed and operated according to the most stringent safety regulations, accidents, human failures, extreme external events or malicious acts can occur that require the implementation of adequate emergency actions. Since the Chernobyl accident in 1986, many efforts have been devoted to improving the nuclear emergency response at national and international levels, and emergency planning and preparedness have become a significant activity of the safety provisions needed to put in service a nuclear power plant. National regulations, usually based on international standards, establish the technical requirements for emergency planning and allocate responsibilities to plant operators and governmental bodies in charge of its implementation. Giving a suitable response to a nuclear accident requires efficient coordination among intervention organizations, emergency coordination centres are operated to facilitate such coordination, and regular exercises are performed to train intervention staff and improve emergency plans and procedures at every level.

Key words: emergency plans, emergency response, coordination centres, intervention organizations, international standards and recommendations.

12.1 Introduction

Nuclear and radiological emergencies can occur in a wide range of facilities, including fixed and mobile nuclear reactors; facilities for the mining and processing of radioactive ores; facilities for fuel reprocessing and other fuel cycle facilities; facilities for the management of radioactive waste; the trans-

This chapter is the copyright of the International Atomic Energy Agency (IAEA) and is reproduced by the Publisher with the IAEA’s permission. Any further use or reproduction of the chapter, in whole or in part, requires the permission of the IAEA. The chapter has been written by a staff member of the IAEA in his/her personal capacity and not on behalf of the IAEA or the Director General of the IAEA. The views expressed in the chapter are not necessarily those of the IAEA and that the IAEA disclaims all liability in connection with the chapter and any use made thereof.

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port of radioactive material; sources of radiation used in industrial, agricul­tural, medical, research and teaching applications; facilities using radiation or radioactive material; and satellites and radio-thermal generators using radiation sources or reactors. The common characteristic of nuclear and radiological emergencies is that both involve hazards associated with ion­izing radiation. In coherence with the rest of this book, this chapter is specifically aimed at emergency planning at nuclear power plants.

Nuclear facilities contain large amounts of nuclear material that can generate radioactive material by a chain reaction or by activation of stable nuclides that have been exposed to high neutron flux. Nuclear reactors can accumulate a large amount of radioactive materials, depending on their thermal power, the fuel burn-up and the time elapsed since the last shut­down. Multiple barriers contain these radioactive materials and prevent their radiation from damaging facility workers and the environment. Some critical components of a nuclear facility, such as the reactor core, need per­manent cooling because radioactive decay of fission products generates a large amount of energy that could damage them if it is not extracted effi­ciently. An accident or an intentional action could disable the reactivity control systems, the cooling systems or the barriers containing radioactive materials. In this case, large amounts of these materials could escape to the environment. The energy accumulated within the facility can contribute to the spreading of radioactive materials into the environment over a wide area.

The fundamental safety objective in the use of nuclear and radiation techniques is to protect people and the environment from harmful effects of ionizing radiation. This objective has to be achieved without unduly limit­ing the operation of facilities or the conduct of activities that give rise to radiation risks. To reach this objective all reasonable efforts must be made to prevent nuclear or radiation accidents and mitigate their consequences.

The most harmful consequences arising from nuclear facilities and activi­ties have come from loss of control over the nuclear reactor core, nuclear chain reaction or radioactive source. Consequently, in order to ensure that the likelihood of an accident having harmful consequences is extremely low, measures have to be taken:

• To prevent the occurrence of abnormal conditions, including breaches of security, that could lead to such a loss of control

• To prevent the escalation of any such failures or abnormal conditions that do occur

• To prevent the loss of control over radioactive sources.

Taking measures towards achieving these goals by undertaking interven­tions, which are defined as any action intended to reduce or avert exposure or the likelihood of exposure to sources which are not part of a controlled practice or which are out of control as a consequence of an accident, is governed at all times by the principles of justification and optimization recommended by the International Commission on Radiological Protection, ICRP (ICRP, 1991, 1993). According to the ICRP, any proposed interven­tion that does more good than harm is justified, and the form, scale and duration of any intervention shall be optimized so that the net benefit is maximized.

Every nuclear facility is designed to prevent any accident that can occur according to the applicable regulation. Two approaches are commonly used to demonstrate the compliance with regulation: the deterministic approach is used to demonstrate that the design is enough to prevent all regulated design-basis accidents and mitigate their consequences if they were to occur; the probabilistic methodology is used to verify that the accidents behind the design basis, that is the so-called severe accidents, should have a very low probability of occurrence and their consequences should be mitigated by dedicated design features. In addition, every nuclear facility has an emergency plan to be activated in case of an accident or malicious act to prevent severe damage to the facility and uncontrolled release of radioactive material, which could produce direct or delayed health effects on facility workers and the population that could be affected by radioactive material released.

The IAEA’s goal has been, and remains today, to draw soundly based safe­guards conclusions through effective and impartial implementation of safe­guards agreements. In fact, the IAEA’s safeguards conclusions regarding correctness and completeness of a State’s declaration for States with com­prehensive safeguards agreements in force depends on the extent to which the Agency is equipped to detect undeclared nuclear material and activities in such States. Under a safeguards system that is based on INFCIRC/153 (Corrected) (IAEA, 1972) alone, the IAEA is limited in its ability to assess undeclared nuclear material and activities. It is recognized that with the AP-related access provisions, availability of expanded State-declared infor­mation and broader access to locations in the State, the Agency’s capability to detect and deter undeclared nuclear material or activities is significantly advanced.

When both a CSA and an AP are in force for a NNWS, and the IAEA finds that there is no indication of the diversion of declared nuclear material from peaceful activities, and no indication of undeclared nuclear material and activities for that State, the IAEA is able to draw a safeguards conclu­sion for the State that ‘all nuclear material remained in peaceful activities’. However, if the evaluations regarding the absence of undeclared nuclear material and activities for a State remain ongoing as part of the State evalu­ation process, then the IAEA concludes for the State that ‘declared nuclear material remained in peaceful activities’.

In those NNWSs where a CSA is in force alone (i. e., AP is not in force), based on the IAEA’s findings that there is no indication of the diversion of declared nuclear material from peaceful activities in the State, the IAEA is able to draw a conclusion that the ‘declared nuclear material remained in peaceful activities’ for that State.

In the case of NNWS Parties to the NPT who have not yet brought com­prehensive safeguards agreements with the IAEA into force as required by Article III of the NPT, the IAEA cannot draw any safeguards conclusions.

The waste packages that are produced have been adapted to the require­ments for storage and transport as well as for disposal. Different types of packages are used. The most common are standard 220-litre steel drums or standard 10- or 20-foot shipping containers. Other types of containers are steel packages of other sizes and packages with a concrete wall that pro­vides some shielding. The packages are normally clean on the outside so that the further handling can be made without the need to consider con­tamination. The packages, however, still emit radiation that needs to be considered during the handling. In many cases the radiation level is such that the packages can be handled, stored and transported without extra shielding, i. e. the packages fulfil the transport regulations. For waste with a higher activity concentration, the dose rates from the waste packages are higher and they will need extra shielding during handling, storage and transport.

LLW and ILW can be stored in fairly simple warehouse-type buildings. Normally the walls are made of concrete of appropriate thickness to provide shielding for the outside.

Transports of LLW and ILW need to fulfil the transport requirements. LLW packages that by themselves fulfil the requirements can be trans­ported in simple standard shipping containers, while packages with a higher dose rate will need to be transported in sturdy thick-walled containers. In many cases it should be enough to fulfil the requirements for so-called type A containers, while in some cases with a higher activity concentration type B containers will be needed (IAEA, 2009c).

LLW and ILW can be transported in a similar way to spent fuel and high — level waste on trucks, trains or ships, depending on the locations of the nuclear power plant and the repository.

It must be remembered that there is always a gap between intuitive percep­tions and probabilistic evaluation of risk, in any field: we know that the probability of having a fatal accident when travelling by plane is far lower than having one when travelling by car but, nevertheless, many people are more afraid of being in planes than they are of being in cars. In the energy field, many studies comparing lethal risks resulting from different energy sources (ExternE, NEA, 2010) show that nuclear energy’s risk of a lethal accident is lower than that for fossil sources (coal, oil and even gas). Nevertheless, the risk of accident is more spontaneously linked to nuclear power than to coal mining or oil extraction. This risk remains the main argument of nuclear opponents and it is also an obstacle for people who have ambivalent perceptions of nuclear energy.

In the 2007 Eurobarometer, respondents had to choose between two answers: ‘The advantages of nuclear power as an energy source outweigh the risks it poses’ and ‘The risks of nuclear power as an energy source out­weigh its advantages’ (NEA, 2010: Fig. 2, p. 22). With regard to nuclear power, people’s threats are focused on catastrophic accident and radiologi­cal risk for human health, often seen as insidious in the neighbourhood of nuclear sites. Objective knowledge may limit fear of these threats, but there always remains some unconscious distrust. But the more people feel well informed on nuclear safety, the less they feel threatened by nuclear safety risks (NEA, 2010, pp. 22-23).

The best way to convince people of nuclear safety is by the example of safe operation: this is why confidence in safety authorities is more pro­nounced in nuclear countries than in non-nuclear countries and, moreover, more pronounced in the neighbourhood of nuclear plants (Eurobarometer, NEA, 2010, p. 22): 59% of respondents in nuclear countries think that nuclear plants can be operated safely against 31% who do not. This puts the NIMBY syndrome into perspective: opposition particularly applies before the building of a nuclear facility in newcomer countries but is less observed in nuclear countries in the neighbourhood of nuclear plants.

The selection of any new site for a large industrial installation requires a systematic approach, as described in Fig. 18.1. First of all, a whole country or a region of it is selected based on economic considerations, proximity to an electricity market and social demands, such as the convenience of boos — tering the development of a particular region.

Within the region, selection of one or more zones will have to be deter­mined by a general analysis of some basic parameters. At this first stage, the availability of cooling water is the most restrictive technological require­ment; generally the areas of interest are limited to rivers, lakes or coastal sites. Artificial lakes could also be built on smaller tributaries and the use of cooling towers may open more possibilities, although the proximity to a large body of water is always recommended.

An analysis of the geology of the region originally selected will determine which areas must be discarded because of high seismicity or for other reasons; the meteorology of the region will determine the hazards associ­ated with extreme meteorological events; zones that are densely populated or near large population centres (over 25,000 residents) will also be dis­carded as it would be difficult to establish efficient emergency procedures; and sites close to large industrialized areas or areas with high agricultural

or ecological value should also be dismissed. The systematic approach of all these criteria will divide the region in question into zones or areas in which NPPs may be situated. At this time, a gradation of the areas found could also be established. Countries have evaluated the maximum nuclear capac­ity which could be installed along a given river, large lake or coastal region.

The zone or zones of interest are then studied in depth to determine the optimum sites where the plant or plants could be built. Two types of studies are conducted; on the one hand, detailed economic, geological, hydrological, meteorological and social and demographic studies will determine some basic plant design parameters, while on the other hand the plant or plants to be constructed will determine some basic requirements from the site, mainly related to the ultimate heat sink, redundant electrical power supply, the need to have an efficient emergency management system, the release of radionuclides during normal operation and accident conditions, the man­agement of radioactive waste, and the size and geometries of the buildings to be erected.

The initially separated studies described above are later subjected to a compatibility study between the plant and the site, covering all types of parameters which constitute the basis for the selection. The site information gathered and the compatibility of the site and the selected technology or technologies will constitute the basis for requesting the site approval from the Regulatory Body in accordance with the regulations of the country.

In the past, governmental institutions and large utilities, under their areas of influence, have conducted studies to determine the best locations for building nuclear power plants and fuel cycle installations. For new entrants the development of such a bank of potential sites is highly recommended. The current social opposition to nuclear power makes it difficult to find new sites for nuclear power plants and related facilities.

A section of the SS document should be dedicated to specifying the scope of supply for nuclear fuel and associated services. Alternatively, this portion of the scope could be included in the nuclear fuel (NF) document of the BIS, which would be a comprehensive, self-supporting document dedicated entirely to the scope of supply and services, technical requirements and commercial conditions for nuclear fuel.

Standard practice is to request the following from the complete plant supplier (turnkey approach), from the nuclear island supplier (split-pack­age approach) or from the NSSS supplier (multi-package approach): [105]

draulic design documents; provision to the owner of all necessary fuel data for him to achieve fuel procurement from third parties, if he should so decide in the future; and supply of all quality assurance and quality control manuals, procedures and records related to the nuclear fuel supply.

• Investment for reload batches. As an option, the bidder is usually requested to submit a proposal for the provision of a limited number of reload batches (usually two or three, sometimes more), sufficient for the owner’s fuel specialists to familiarise themselves with the nuclear fuel and reactor core design and gain sufficient knowledge to decide whether to continue with the original fuel supplier or purchase it on the market from third parties. An alternative to requesting a specific number of reload batches consists in requesting the supply of reload batches neces­sary for a given period of operation (e. g. 4 or 5 years), after which familiarisation is expected to be achieved.

• Together with each subsequent reload, the supplier is normally requested to provide the associated fuel management services (e. g. core design, safety analysis, reload licensing).

As already described, an application for a site license, whether part of a more general license or a stand-alone application, needs to identify the precise site on which the applicant proposes to build a nuclear power station, and the characteristics of the site need to be described, as do the mutual interactions between the plant and the site. The submitted docu­mentation should be analyzed by the RB against established safety prin­ciples, such as: [110]

of implementing emergency countermeasures (including possible evac­uation of areas around the site). As already mentioned, the potential difficulties of a nuclear emergency within a more general emergency should also be considered by the RB.

• The social, economic and environmental effects of the NPP. An NPP will have effects on the surrounding population and the environment. The RB should consider the population density and the proximity to large and medium cities, technological parks, recreational areas, national parks and heritage locations which may become heavily affected by radiation releases of a certain magnitude.

The analysis by the RB experts requires knowledge and experience in earth sciences to determine the magnitude of the maximum possible natural events, as well as experts on man-made events, and people with experience of emergency planning. The best help to the RB will probably come from national institutions dealing with such phenomena and activities. A site license will typically contain requirements and limitations on the site’s preparation activities that may be conducted before construction begins.

Many RBs require that a local environmental impact statement (EIS), assessing the impact caused by the future power plant, is also submitted by the applicant and analyzed by the RB at the time of site evaluation. It is also customary at this stage to inform stakeholders of the project and to allow them to formally make representations detailing any reservations they may have about the project. Some countries, for example the UK, require that a Public Inquiry should be called at which the applicant is invited to present their case and to hear and consider the contributions and concerns raised by participating stakeholders. The involvement of stake­holders in nuclear issues before deciding the construction of a new nuclear power plant is recommended in INSAG-22 (INSAG, 2008a).

Self-assessment programmes are a means by which practitioners of various programmes or functions take time out from their normal day-to-day activi­ties to objectively assess the way in which they are conducting their activi­ties against a set of internationally recognised criteria. Normally, WANO peer review or OSART performance objectives and criteria are used in such processes. The assessments are conducted with in-house personnel and can follow a similar format, but with limited scope, to a peer review exercise.

5.1.7 Corrective action programmes

Corrective action programmes (CAPs) are designed to enable the reporting of any conditions adverse to quality by any member of staff working at an NPP. The CAP programmes are also used to classify and trend issues, to record and monitor progress against actions raised in response to reported issues.

Corrective action programmes are also used to record and trend actions arising from other forms of evaluation such as peer reviews, Op Ex, QA audits and self-assessments. Having the corrective actions from all sources of evaluation enables the operator to ensure that common causes and con­tributors to issues raised are treated more efficiently and effectively.