The basic safety principles applicable to nuclear power plants have been well known for decades. They were first documented by the IAEA

International Nuclear Safety Advisory Group (INSAG, 1988) and were updated in 1999. In 2006, the IAEA published a broadly supported docu­ment entitled Fundamental Safety Principles (IAEA, 2006). These docu­ments stop short of defining the requirements of any specific power plant design, but do provide a prospective plant owner with all of the principles on which the modern world’s nuclear safety approaches are based.

This section could be titled ‘learning from experience’. This issue is some­what broader, however, as necessitated by a complex system such as nuclear energy. This issue becomes extremely important to support the justification of a new nuclear program, because the experience must be gained rapidly, essentially without the benefit of prior operating experience by the operat­ing company. It has been found very useful to study abnormal events that have occurred in nuclear power plants in the past. By this means the newly initiated operating staff get a clear picture of how mistakes have been made, how consequences of those mistakes have been dealt with, and how future operation can benefit from the lessons learned (Duffey and Saull, 2003, 2008). Further, it has been found that the causes, patterns and frequencies of failure are very similar across a wide range of human endeavour. The nuclear energy enterprise stands out (Weick and Sutcliffe, 2007) as a high-performance industry in terms of its low risk of high-consequence accidents.

Notwithstanding the unattributability of stochastic effects, it should be noted that under present knowledge, it can be demonstrated that risks (rather than factual effects) can in fact be attributable to radiation exposure situations, even to those delivering small doses. Therefore, for reasons of radiation protection, and also of duty, responsibility, prudence and precau­tion, it is necessary to ascribe nominal radiation risks to prospective expo­sure situations. Thus, nominal risk coefficients should be developed from the observed increased incidence of radiation effects at high doses and be used solely for radiation protection purposes (see hereinafter).

Once emergency plans have been activated, the operator is responsible for timely and accurate transmission of information about the evolution of the accident within the plant, to ensure that the public authorities receive data they need for managing the situation. Of special importance are data related to the nature and amount of the radioactive releases from the plant, usually called the source term, because the scope and nature of countermeasures to be implemented depend critically on this parameter. The source term can be evaluated by using data from of the radiometers installed in the main discharge channels in the nuclear facility, e. g. chimneys and ventilation exhaust systems. This method can be used when radioactive materials are released through these channels and the corresponding instruments were not affected by the accident. The source term can also be estimated by using mathematical models that reproduce the physical-chemical behaviour of the plant under accident conditions. Some of these have been adapted for use in emergency situations and are available in the emergency coordina­tion centres operated by operators and regulatory authorities (IAEA, 2003b).

In case of maximum severity, the emergency coordinator can decide the implementation of precautionary urgent protective action to prevent severe deterministic health effects by keeping doses below those for which inter­vention would be expected to be undertaken under any circumstances. This situation is extremely unlikely and it is expected that the emergency coor­dinator would have enough time to decide the implementation of counter­measures based on dose estimation.

Estimation of the dose needs detailed meteorological data that can be obtained from the stations existing in every nuclear facility and from regional or national meteorological services. These data are used as input to mathematical models able to predict transport of radioactive materials released in the atmosphere, and to estimate the dose that the people living in the areas affected could receive due to radiation from a contaminated cloud or radioactive aerosols deposited in soil or waters. The dose can also be evaluated by using the radiometric instrumentation that is available in the emergency areas as part of the means and resources arranged during the preparedness phase of the emergency plans. This instrumentation is composed of automatic radiation surveillance networks, mobile units, per­sonal dosimeters, contamination meters, and sampling stations and analyti­cal laboratories and procedures to evaluate contamination of affected pathways, e. g. air, soil, foods and water.

The emergency coordinator can evaluate the radiological situation by using the different methods available to estimate the source term, the spread of contamination and the dose. Use of an adequate technique is a compromise decision between the need for quick or accurate results. The use of mathematical models allows very quick results, even predictive, but can involve some uncertainties. The use of radiometric measures is more accurate but can lead to delay, especially if the results are obtained by sample analysis or with off-line instruments. Automatic radiation surveil­lance networks can reduce the time needed to obtain results, but their accuracy, sensitivity or location could be inadequate for taking decisions. The emergency coordination centres are equipped with systems based on different techniques and their operators are trained in using all of them and taking decisions based on combining the results obtained from all of them.

Upon consulting with the regulatory authority, the emergency coordina­tor decides the implementation of urgent protective action to prevent sto­chastic effects to the extent practicable by averting doses, in accordance with international standards. The decision is based on the dose rate and contamination levels existing in the affected area, and the dose that can be averted by applying appropriate countermeasures. Public authorities can take into consideration other factors influencing the implementation of countermeasures. In this regard, meteorological conditions, seasonal demog­raphy and coincidence with other catastrophic events such as earthquakes are examples of circumstances that have to be taken into account in the decision. Finally, the emergency coordinator transmits his or her decisions about emergency actions to emergency response teams (rescue brigades, radiation protection, health services, police, and civil defence teams) for implementation.

During emergency response, the emergency coordinator has to pay special attention to ensure that easily understandable information about existing hazards, emergency decisions and countermeasures to be imple­mented is properly transmitted:

• Directly to the permanent, transient and special population groups or those responsible for them and to special facilities within the emergency zones, for getting an adequate undertaking of emergency decisions and their full collaboration in implementing emergency measures

• To emergency coordination centres to act cooperatively

• To the media to ensure that all stakeholders have adequate information on emergency operations to act properly if their support is required

• To international partners, international organizations and national sig­natories of bilateral agreements, to facilitate the adoption of adequate emergency actions in their own territories by the relevant emergency coordinator.

During emergency operations, special attention should be paid to protect emergency responders who may undertake intervention in order to save lives or prevent serious injury due to doses that could cause severe deter­ministic health effects, take action to avert a large collective dose, or take action to prevent the development of catastrophic conditions.

Activation and implementation of emergency plans could be especially difficult when response to a nuclear accident has to be given in an area that has been simultaneously affected by an extreme natural or anthropogenic disaster. In this case, the emergency coordinator has to pay special attention to coordinating implementation of radiological and non-radiological coun­termeasures with the relevant authorities.

Contrary to spent fuel and high-level waste, there is no technical advantage to delaying disposal of low — and intermediate-level waste. There is no heat production that needs to be considered, nor will the volume of waste to be disposed diminish with time. Most countries with nuclear power plants have thus developed disposal facilities. This provides the possibility of optimizing the management scheme for these wastes.

A basic principle for the management of low — and intermediate-level waste is to minimize the volumes that need to be disposed of. The first step in minimization is to avoid producing the waste, e. g. by avoiding bringing extra material like packaging into areas that are considered contaminated. Also decontamination and recycling of metals serve this purpose.

For the unavoidable waste, the management system should be designed such that it optimizes the use of resources for the whole management chain. This means that treatment and conditioning methods should be chosen to produce packages that can be handled in the transport and storage system and disposed of in the existing disposal facility. A key demand is that it should be possible to handle the waste packages as solid entities that are clean on the outside.

The management system for low — and intermediate-level waste includes sorting, treatment, conditioning and packaging systems, storage facilities and disposal facilities, and the necessary transport equipment to transport the waste between the different steps in the process. Sorting, treatment, conditioning and packaging systems are normally included at the nuclear power plants, but there are also examples of centralized or transportable conditioning facilities. For solid wastes, compaction or incineration is used to reduce the volume. Wet wastes, e. g. liquids or ion exchange resins, are solidified in packages, e. g. with cement or bitumen. In some cases ion exchange resins are stored and disposed of unconditioned in high-integrity containers.

Disposal of low-level and very low-level waste is an industrial practice, although not yet implemented in all countries, often for lack of public acceptance. Very low-level waste is disposed of in fairly simple landfills, while low-level waste is disposed of either in engineered facilities on the surface or in underground caverns. Examples of engineered facilities can be found in China, France and Spain, while underground caverns are in use in the Czech Republic, Finland and Sweden. Intermediate-level waste will be disposed of in rock caverns at a certain depth. Some facilities are under construction, e. g. in Canada and Germany.

More technical details about management of low — and intermediate-level waste can be found in Section 14.5.

Investment costs for all power plants began to ascend quite steeply around 2005 and by 2008 had more than doubled for conventional coal technology and especially for nuclear power. This sharp increase coincided with the rapid increase in world market prices of energy and materials (e. g. cement and the full spectrum of metals). While these price hikes have clearly been one element pushing investment costs, they alone do not explain their mag­nitude. They are rather the result of a combination of several coinciding factors such as an above-average demand for generating capacity in Asia, an ageing fleet of power plants in North America and Europe requiring replacement or refurbishment for environmental reasons, as well as effi­ciency improvements due to high fuel prices and a global power equipment manufacturing industry characterized by relatively minimal expansion for over a decade — hence little spare manufacturing capacity.

Regarding nuclear power, globally only a few manufacturers were capable of producing heavy forging equipment such as reactor pressure vessels and steam generators. By 2008 lead times of 50 months and more had become commonplace. Backlogs started to accumulate with the licence extensions for existing reactors which often require replacing steam generators and other heavy components. The rising interest in new nuclear build and the accompanying pre-orders further added to the backlog. Full order books allow manufacturers to command higher margins and thus exert upward pressures on prices.

By 2007-08 prices for new nuclear build announced by utilities that are expected to deliver the first kWh to the grid sometime during 2017-20 started to ascend steeply, deviating considerably from the previous $1000 to $2500 per kW range (NEA and IEA, 2005). For example, in October

2007 Florida Power & Light released projected investment costs of $12.1 billion to $17.8 billion for two new Westinghouse AP1000 reactors (1100 MW each) or $5500 to $8100 per kWe at its proposed Turkey Point site. In March

2008 Progress Energy announced that its two new AP1000 units on a green­field site in Florida would cost it about $14 billion or some $6360 per kW(e). In November 2009 Citigroup Investment research put construction costs for new nuclear build in the United Kingdom in the range of $3700 to $5200 per kW(e).

In May 2010, Progress Energy raised the estimated cost of its proposed 1100 MW reactors at the Levy nuclear power plant in Florida from $17.2 billion to $22.5 billion and delayed its start-up to 2021 due to a delay in licensing the reactors (Reuters, 2010).

In contrast, the US Congressional Budget Office (CBO, 2008) quotes $2300 per kW(e) for a generic design in a report published in 2008 which is in line with NRG’s August 2007 estimated cost range for two 1350 MW advanced boiling water reactors (ABWR) to be built in South Texas of $2200 to $2600 per kW(e).

The first two out of a total of six domestically developed 1000 MWe CPR — 1000 pressurized water reactors in China are quoted at a cost of $1850 per kW (WNN, 2010). The first unit is scheduled to begin operating in 2015, followed by the second unit in 2016. Some 87% of the equipment to be used is being provided by Chinese suppliers (WNN, 2010).

Common to all these cost quotes is that they do not convey what is included and what is not. In essence these quotes are not comparable, although in the public mind they are all considered real. Clearly, this diver­gence of investment costs causes confusion and, taken at face value, seri­ously questions the economics of new nuclear build.

The exclusive focus on nuclear investment costs as a single data point ignores the effects of the material price hikes, the manufacturing constraints for power equipment and the shortage of skilled labour on all electricity generating technologies. Given the favourable material intensity per MWh of electricity generated (on a lifetime basis) from nuclear power compared with fossil and renewable alternatives, the energy and material price hikes have affected NPP costs less than the alternatives. Figure 15.9 compares the material-related change in generating costs for new power projects between 2005 and 2008 just before the onset of the financial crisis (ENEF, 2010). While all generating options saw steep increases in material-related costs, nuclear power was least affected.

But the capital cost quotations by utilities suggest a different picture, so which other factors may explain the recent enormous escalation of nuclear investment costs? At least four potential causes have been already identi­fied: (a) varying definitions of investment costs, (b) boundaries of the analy­sis, (c) interest rates and market structures, and (d) price expectations (inflation) for materials, equipment and labour. The next paragraphs attempt to put the above divergent cost quotations into perspective with the help of a brief numerical example.

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This will be an important feature of most land-use planning systems and provides interested parties with the opportunity to influence the outcome of planning decisions. Part 5 of the PA 2008 has fundamentally reformed the way in which the UK approaches consultation and imposes a substantial burden on applicants to consult with affected communities and the local authorities. The onus is on applicants to be satisfied that they have dis­charged their consultation obligations at the pre-application stage. This is a measure which was introduced to improve the efficiency of the planning system, and it is hoped that front-loading the consultation exercise will enable problems, including local environmental impacts, to be identified at an earlier stage in the process. Applicants are required to take account of the responses to consultation when deciding whether to proceed with a given project, and the IPC/MPIU will eventually be provided with a copy of a consultation report detailing what has been done to consult, any rel­evant responses and how they have been accounted for. Section 55(4) of the PA 2008 obliges the IPC to have regard to the report when making their decisions.

The relevance of site characteristics, mainly population distribution, on the safety of NPPs was soon recognized. The ideas and concepts developed by the United States former Atomic Energy Commission (AEC) since 1962 have been maintained until now and have provided the basis for evaluating the site for NPPs; they also have shaped the design basis of the currently operating reactors. Because of the large impact of these considerations, it has been found of interest to present a short account of this historical development and the current situation regarding this matter.

The bid prices quoted by the bidder for the scope of supply and services offered are usually referred to as ‘base bid prices’. They can be fixed, firm, unit prices or just budgetary/estimated prices, which the bidder shall indi­cate in his bid.

A fixed price is binding on the bidder if it is accepted by the owner during the bid validity period. However, it is not subject to adjustment as a result of escalation and is based on the delivery of the item at the commercial operation date (COD) of the plant.

A firm price is also binding on the bidder if it is accepted by the owner during the bid validity period and is subject to adjustment as a result of escalation. The bidder shall include in his bid the escalation formula appli­cable to each firm price.

The bidders will be requested to submit a price breakdown in their bid. The level of price breakdown should be sufficient to enable financial evalu­ation of the bid and its comparison with other bids. The IAEA accounts system (IAEA, 2000) provides good guidance regarding price breakdown level. The bidder’s price breakdown schedule should clearly indicate the kind of price associated with each scope package or item: whether it is fixed price not subject to escalation, firm price subject to escalation, unit prices, budgetary prices, or any other price category foreseen in the CC document. In summary, the bidder shall specify which part of the bid is quoted fixed price, which part is firm price with escalation and which parts are quoted in other price categories.

When it comes to price breakdown, it should be understood that bidders may be reluctant to provide a high level of detail in the segregation of the bid price. Scope packages or items quoted as fixed/firm prices should require no breakdown or a small one. A reasonable and practical level of price breakdown that can be requested from the bidder is to indicate the price for each major account (for example, for each two-digit or three-digit account) of the IAEA accounts system (IAEA, 2000).

For scope packages and items quoted as non-fixed/firm prices, the owner should request from the bidder a higher level of detail for the price break­down, to set the basis for negotiations.

Following are some aspects to be considered when specifying the level of price information to be provided by the bidder: [108]

a single currency, in which case the fluctuation in the exchange rates with respect to the common currency will be at the bidder’s charge.

• Prices should preferably be presented in tabular form, with a row assigned to each scope item for which a segregated price is offered. Typical column headings of the price table are scope item number and description, price type (e. g. fixed/firm, unit price, budgetary price), per­centage of price in foreign and/or local currency, and remarks (if necessary).

19.12.1 Price revisions

As indicated above, the base prices quoted may be fixed and not subject to escalation, or firm and subject to escalation, or any other type of non-fixed/ firm price. The owner shall specify in the CC document of the BIS his requirements concerning the methodology and price adjustment formulae to be proposed by the bidder. Typically there should be more than one price adjustment formula. For example, there can be:

• One price adjustment formula for the revision of the base price of scope items associated with the delivery of services for which only labour cost indices will be used

• One (or more) price adjustment formula for the revision of base prices quoted for the scope of supply items involving manufacture or construction, for which both labour and material cost indices will have to be considered in the formula. More than one material cost index may also be included in the formula, when different categories of mate­rials having differentiated cost variation over time are used in the manufacture.

The labour and material cost indices used in the price adjustment formu­lae shall be those published by an official institute of the country of refer­ence and should have a long record of publication (at least 10-15 years). Should any index be discontinued, the index which officially replaces the discontinued one shall be applied from then on; when there is no index to officially replace the discontinued one, the owner and the successful bidder (the contractor) shall agree on the selection and application of another existing and widely recognised index that reflects as closely as possible the same items and provides results similar to those of the original index.

The NPP will have to be shut down periodically for extended periods for refuelling or for the carrying out of major maintenance work. Maintenance work is generally conducted during outages for refuelling. All activities during such extended outages should be carefully checked by the RB from a safety angle. At the end of such outages, a report should be submitted to the RB giving details of all safety-significant work done, including results of the in-service inspections and surveillance checks carried out. This report should be formally reviewed by the RB and clearance for restart of the reactor given, after confirming that the NPP meets the licensing conditions.

A large number of outside personnel, such as contractors, are likely to be engaged during such outages to carry out specific work. The RB should ensure that these personnel are given necessary training to carry out the activities, following specified radiation protection procedures and other safety requirements.