License applications are formally submitted to the RB. The RB first verifies that the information provided in the application is sufficient for conducting a proper safety review; if this is not the case, the applicant is requested to submit the information required. Once the RB is satisfied, the application is formally accepted and a schedule for the evaluation process is estab­lished. The way in which the evaluation is conducted is country dependent but there should always be a person managing the process and a large group of specialists for the various fields of experience required. The end point of the evaluation is the completion of an SER.

The RB may not be sufficiently knowledgeable in certain specific areas; in such cases, help can be obtained from various sources. For new entrants, the most relevant source would in most cases be the RB in the country of origin of the NPP design, though an experienced group of international senior regulators could also help establish a knowledge base in a new regu­latory system. The IAEA can provide a variety of services, including advice to the assessment manager. Technical help and advice can also be requested from Technical Support Organizations (TSOs), as is very common in the European practice, available in the country’s own institutions, such as nuclear research organizations, universities and academies. Contracts with national and international private institutions could also support the evalu­ation process. This help does not take away from the RB the responsibility of preparing the SER which results from such analysis.

The SER is a substantial document, generally developed by following well-established procedures. The main aim is to verify compliance with the regulatory requirements applicable to the license under consideration. During this process, generally large lists of clarifying questions or require­ments for further information are addressed to the applicant. A prompt and precise response to the RB enquiries speeds up the evaluation process. The SER ends with a final evaluation and with a complete set of limits and conditions to be followed when performing the activities envisioned in the requested license. It may also include a reference to the requirements for the next license.

Nuclear technology has a specific concern which makes it different from other industries: the work in radioactive environments and, as a conse­quence, special requirements related to safety and radiological protection which are needed to be taken into account in all activities related to the nuclear industry. Such special requirements correspond to specific compe­tencies which need to be thought about when planning human resources needs.

In a new nuclear programme, whether it is the first nuclear power plant or enlarging the current fleet, stakeholders should make a realistic assess­ment of their educational and training capabilities to develop nuclear knowledge in the quantity and quality needed.

It is strongly recommended for those countries starting nuclear programmes to join some of the following international associations and initiatives.

International atomic energy agency (IAEA)

The International Atomic Energy Agency (IAEA) is one of the interna­tional organizations that can support training for capacity building through the following strategies:

• Support for in-house training and sustainability through the ‘Train the Trainer’ approach

• Promotion of networking based on Asian Nuclear Safety Network experience

• Promotion of workshops and conferences.

IAEA general training tools for capacity building are multimedia train­ing courses, web-based knowledge sharing, tailored training sessions and workshops, the Centre for Advanced Safety Assessment Training and the promotion of bilateral and multilateral exchanges of trainees.

In 1994 was constituted the Technical Working Group on Training and Qualification (now known as ‘Managing Human Resources in the Field of Nuclear Energy’, TWG-MHR). This international group, with the participa­tion of all the countries with nuclear interests, meets every two years at the IAEA’s Vienna headquarters. This biennial meeting is a valuable opportu­nity, as it is the only such worldwide gathering on this topic. Its objectives are:

1. To exchange information on status and trends concerning NPP person­nel training and qualification in Member States.

2. To recommend future IAEA activities related to NPP personnel train­ing and qualification.

3. To review the Agency’s activities in the subject areas performed in the past two years and provide recommendations to implement the IAEA programme in the next two years.

Initial fuel loading marks the start of operation of a NPP and therefore the complete operational discipline should be in force before the first fuel assembly is loaded in the reactor core. This would include establish­ment of the reactor operating island, implementation of security provisions, zoning of the operating island for prevention of spread of radioactive contamination, availability of licensed operating staff and availability of approved technical specifications for operation, operating and maintenance procedures, emergency operating procedures and emergency preparedness plans.

Achieving first criticality of the reactor is the first major step in NPP operation. For this the expected configuration of the reactor core including the anticipated position of control rods will be worked out in advance and all special instrumentation for reactor startup will have been commissioned. After satisfactory achievement of first criticality, power will be raised in steps with clearance from the regulatory body at every pre-decided stage. Some of the commissioning tests that can be carried out only with the reactor at power will now be done and their results reviewed by the com­missioning review group and the regulatory body.

As mentioned earlier, the O&M staff and local technical services person­nel of the reactor physics group, the fuel handling group and the radiation protection group should be fully involved at all stages from first criticality to operation at rated power, including direct participation in the commis­sioning tests made with the reactor at power.

Strategic materials for nuclear weapons proliferation can be obtained from the nuclear fuel cycle. These materials can be uranium-235 from the first part of the cycle, or manmade plutonium-239 produced in the reactor and separated in the reprocessing side of the fuel cycle. Once the strategic materials are available, the design, construction and deployment of nuclear weapons is, although very costly, not a big technical problem, and is one which could be mastered by many. Light and heavy water reactors are the ones in operation now and are the candidates for short — and medium-term deployment, so the following considerations are limited to such reactor models; the future use of fast breeder reactors using the uranium-238/plu — tonium-239 fuel cycle will need further considerations, which are outside the remit of this chapter.

Light water reactors use natural uranium enriched in uranium-235 from its natural value of 0.7% up to 3-5%. Enrichment is a well-known physical isotope separation process achieved by gas diffusion through membranes or by ultracentrifugation; laser separation is now laboratory proven but not yet deployed on a commercial scale. The most available and economical way to produce enriched uranium is by ultracentrifugation, and the same equipment can serve to reach reactor enrichment levels of up to 90% weapons-grade enrichment. This process can be fully achieved by any rea­sonably developed state wanting to follow this path.

Plutonium-239 is an activation product of uranium-238 present in the reactor, which accumulates slowly within the fuel matrix; over time, other isotopes of plutonium which are not fissile start to accumulate (mainly plutonium-240). Weapons-grade plutonium-239 is found when irradiation times are very short, of the order of a few months. The fuel cycle in a power plant is much longer than that, and therefore the plutonium produced (called reactor-grade plutonium) is contaminated with the other isotopes, although it could also serve to produce lower-yield nuclear weapons. In any case, the plutonium produced has to be separated from the other compo­nents, uranium-238 and unburnt uranium-235 and fission products. This separation can be easily achieved by a well-known chemical process called PUREX which is easily accessible, although the presence of the highly radioactive fission process complicates the chemical separation. A 1 GWe LWR needs some 20 tonnes of fuel per year and generates about 200 kg of reactor-grade plutonium.

Efforts have already been made (and new solutions are being developed) to make the fuel cycle proliferation-proof against any desire to use strategic materials for non-peaceful purposes. Although limited advances have been achieved, it is clear that there will not be any easy technical solutions to avoid proliferation; only policy and diplomacy can serve to reduce the risks, as explained by the Nobel Prize winner, Burton Richter (Richter, 2008). The Non Proliferation Treaty (NPT) and corresponding safeguards under the control of the IAEA are the diplomatic instruments that have been created to reduce such risks. This matter is considered in depth in Chapter 13 of this book.

Although very effective, the NPT and its safeguard requirements cannot be absolutely proliferation proof. Policy proposals have been formulated within the IAEA and leading countries to internationalize the fuel cycle by providing enrichment and reprocessing services by the most developed countries under special international controls. The Global Nuclear Energy Partnership (GNEP) proposed by former President Bush is another example. Both initiatives have not yet been fully developed. All these tech­nical, political and diplomatic efforts have considerable potential to reduce, but not completely eliminate, the risk of proliferation.

The risk of proliferation is highly dependent on the geopolitical confron­tations within the world and is therefore difficult to evaluate. But the culprit is not the peaceful uses of nuclear power: in fact, the production of strategic materials is cheaper and more effective if undertaken at dedicated instal­lations. In practice, effective technologies, inspections and treaties will reduce the risks of proliferation as far as possible, and this matter should not be a deterrent for the peaceful development of nuclear energy.

This factor usually receives the most attention in day-to-day discussions because of its importance within the political process and therefore the emphasis on public protection by the safety regulatory agency. The owner must, of course, justify adequate safety to the regulatory authority in order to obtain permission to operate the plant. It also is necessary for the owner to operate the plant safely at all times, in order to maintain the trust and goodwill of the community. This illustrates a fundamental reality; it is that any regulatory agency in a nation with a responsive government must conduct a licensing process that is partly technical and partly socio-political — and the ultimate judge of sufficient safety is the body politic.

The start of plant operations presents management with a new set of chal­lenges. The operating organization is expected to operate the machine safely and productively through a plant lifetime of the order of 50 to 100 years, in other words, for up to four or five complete generations of operat­ing staff. They are expected to retain engineering expertise as well as oper­ating expertise through this whole time period. Fortunately there are tools available that greatly simplify this seemingly daunting task.

It is quite easy to determine the precise state of each component and system when the plant is new, provided the commissioning methodology was sufficient. In a modern plant the methodologies for handover from design, construction, and commissioning to operations includes a complete set of detailed documentation, plus a valuable electronic model of the whole plant. Such a modern computer-aided drafting and design (CADD) model (Didsbury et al., 2000) gives the operating staff a final ‘as built’ description of the plant, down to a finely detailed description of each system, complete with a record of the history and capability of each com­ponent of that system (Petrunik and Rixin, 2003). For the first time, opera­tions have at hand a tool for configuration management that can be used productively throughout the life of the plant.

At any given instant during operation it is possible that some components and subsystems will become unavailable. Given the complete configuration package from the electronic model it is possible to know precisely which components are unavailable. It is even possible to know this in a predictive fashion; that is, prior to start of maintenance, the staff can estimate the change in future unavailability that will be caused by this maintenance operation, and to judge its effect on the risk of continued plant operation during a planned maintenance period. Planning of maintenance is greatly simplified, and regulatory requirements for either continued operation or plant shutdown become clear and unequivocal.

Training offers the second important advantage of the comprehensive CADD model during operation. All systems and components can be ‘seen’ on the computer screens at any time, so that maintenance training is easier even when some area in which maintenance is required is unavailable during at-power operation. Given the long lifetime of the plant, the model presents a useful way to pass plant information from generation to genera­tion. With necessary care and attention given to upkeep of the model, plant information becomes effectively eternal. Obviously, updates of this model can provide a means to record configuration changes that may become necessary during later plant life, such as those due to new regulatory requirements or due to a component manufacturer being replaced by a new one, and so on.

In summary,

• In normal operations of NPPs radiation doses incurred by the members of the public will be insignificant and those incurred by workers will be relatively small, lower than the typically elevated levels of the back­ground radiation that is ubiquitous in nature.

• These radiation doses are far below the threshold doses of deterministic effects. Therefore, the occurrence of deterministic effects in NPPs is prevented.

• Nonetheless, it is assumed that low radiation doses have the potential to induce stochastic effects, such as cancer and hereditable harm, that may become manifest many years after the exposure; the probability of occurrence of stochastic effects at low doses is exceedingly small, although it is assumed to increase proportionally with dose, and the effects are unlikely to be detectable (ICRP, 2005b; Beninson, 1996).

• Conversely, workers involved in an accident within an NPP (perhaps only a small number of the workforce) could also be exposed to high radiation doses, e. g. of the order of thousands of millisieverts. If such dose levels are incurred, clinically visible deterministic health effects are almost certain to appear, usually as burns and other tissue reactions, within days of the exposure, affecting the functioning of tissues and organs with a severity that increases with dose. In severe cases, they can cause the death of exposed individuals.

The effects of different radiation doses and the likelihood of observable consequences are summarized in an extremely simplified manner in Table 11.7 (ICRP, 2005a).

The main responsibility of the regulatory body regarding emergency plan­ning and preparedness is to ensure that emergency arrangements are inte­grated with those of other response organizations as appropriate before

the commencement of operation. The regulatory body ensures that such emergency arrangements provide a reasonable assurance of an effective response, in compliance with safety requirements, in the case of a nuclear or radiological emergency. In discharging this responsibility, the regulatory body assumes the following regulatory functions:

• Establishing radiological criteria for emergency planning, which include, among others, definition of intervention zones according to dose rate or surface contamination levels, adequate countermeasures to protect per­sonnel, the public and the environment, and quantitative reference levels to undertake countermeasures

• Issuing regulation and acceptance criteria for on-site emergency plans, and giving guidance to licensees to develop and implement on-site emergency plans

• Evaluating and approving on-site emergency plans drawn up by the owners as part of the safety documentation required for applying for the authorization of each facility

• Verifying that on-site emergency plans are established according to the applicable regulation, by auditing and inspecting them, and supervising the conduct of pre-operational and periodic emergency exercises

• Requiring modification of emergency plans if it considers that they are inadequate for the facility and site characteristics, the state-of-the-art recommends improving them, or when a new regulation has entered in force

• Advising, supervising and, when needed, requiring implementation of emergency countermeasures to ensure that the exposure of intervention personnel and other affected persons is kept as low as possible and to ensure that actions undertaken to return to normality are carried out in accordance with radiation safety regulations

• Advising national authorities to fulfil their international commitments arising from multilateral or bilateral agreements signed by the State in the field of nuclear emergency.

H. FORSSTROM, SKB International AB, Sweden

Abstract: The generation of spent nuclear fuel and radioactive waste is an unavoidable consequence of nuclear power production. Some of this material needs to be handled with great care and be disposed of, either near the surface for short-lived waste (a few hundred years) or at depth (500-1000 m) in geological formations for long-lived and high-level waste. The spent nuclear fuel also contains material (uranium and plutonium) that could be recycled in new fuel after reprocessing. This chapter provides an overview of the characteristics of spent fuel and different types of radioactive waste and of the steps involved in the management of this material. It also covers the international framework and national policies and strategies.

Key words: radioactive waste, spent nuclear fuel, reprocessing, disposal.

14.1 Introduction

The generation of radioactive waste is an unavoidable consequence of nuclear power production as well as of other applications of nuclear tech­nologies, e. g. the use of radioactive substances in medicine or research. Some of the waste is very dangerous and needs to be handled with great care and be isolated from human beings and the environment. These wastes will also remain dangerous for very long time periods, from hundreds to hundreds of thousands of years. The end point of radioactive waste manage­ment is therefore in most cases disposal, either near the surface for short­lived waste (a few hundred years) or at depth (500-1000 m) in geological formations for the long-lived and high-level waste. To reduce the need for disposal one of the basic principles for radioactive waste management is to minimize the generation.

The main source of long-lived and high-level waste is the spent nuclear fuel. It also contains material (uranium and plutonium) that could be recy­cled in new nuclear fuel after reprocessing. The possible reuse will depend on the economic conditions and, in particular, the development of fast reac­tors. The alternative is to dispose of it directly after 30-40 years of storage.

The spent fuel is thus a good example of the following definition of waste: Waste is a resource at the wrong time and in the wrong place.

In addition to spent nuclear fuel, several other different types of second­ary waste are generated during nuclear power production or during reproc­essing and from the final decommissioning and dismantling of the reactors and auxiliary facilities. Most of this waste is short-lived and classified as low-level waste.

As the waste management will be applied over a hundred years or more it is important to develop appropriate policies and strategies for the waste management, including technical options and definition of clear responsi­bilities for regulating, implementing and financing the waste management system. Although many of the facilities (e. g. for disposal) will only be built several tens of years later, it is very important for a country considering the introduction of nuclear power to develop policies and strategies early.

The IAEA defines radioactive waste as any waste that contains or is contaminated with radionuclides at concentrations or activities greater than clearance levels as established by a regulatory body (IAEA, 2007a). It is recognized that this definition is purely for legal and regulatory purposes and that material with activity concentrations less than clearance levels is also radioactive from a physical point of view.