Как выбрать гостиницу для кошек
14 декабря, 2021
The Advanced Boiling Water Reactor II (ABWR-II), developed by GE-Hitachi, is a further enhancement of the ABWR. It offers a larger power output of up to 1700 MWe, due to a larger core with 1.5 times larger fuel bundles and the control rods arranged in a K-lattice (as opposed to the conventional N-lattice[5]). This new core design may also provide increased flexibility for higher burn-up, use of MOX fuel and higher conversion rate configurations. The ABWR-II also includes a modified Emergency Core Cooling System, and an optimum combination of active and passive heat removal systems, resulting in a design that promises better economics, performance and safety.
The most important information regarding public safety is to determine both the frequency and the consequence of any potential reactor accident. The consequence of a severe reactor accident could, for example, be an excessive dose of radiation to one or more members of the public. The risk of such an event depends, of course, on the amount of radioactive material that could be released — that depends, other factors being equal (e. g. reactor and containment design), on the power level of the reactor under consideration. Smaller reactors do not have the same level of radioactive material in them, and so their inherent risk is lower.
National and international organizations have been established to assist with new program startup. Most work of the Division of Reactor Engineering at the IAEA is dedicated to education and communication between the power programs of member states. In addition, the World Nuclear
Association comprises mainly companies. Current members are responsible for virtually all of world uranium conversion and enrichment production and some 85% of world nuclear generation. Further, the World Association of Nuclear Operators (WANO) has the mission to ‘Maximize the safety and reliability of nuclear power plants worldwide by working together to assess, benchmark, and improve performance through mutual support, exchange of information, and emulation of best practices.’ The WANO organization grew out of the US-based Institute for Nuclear Power Operations (INPO) that was established shortly after the Three Mile Island accident in 1979.
In addition to these broad-based organizations, a number of plant-specific owners’ groups operate around the world. As an example, the CANDU owners group (COG) is a ‘not-for-profit organization dedicated to providing programs for cooperation, mutual assistance and exchange of information for the successful support, development, operation, maintenance and economics of CANDU technology.’ All operators of CANDU plants worldwide are members of COG. Together, these organizations provide major support for any new member, ranging from general education on aspects of this technology, through specific training for operating staff, posting of individuals to operating nuclear units, and cooperative R&D to maintain and improve operating stations. The overall effect is to reduce the operating cost of each plant. Essentially all vendors of nuclear stations have established similar organizations in order to assist operational organizations to maintain modern understanding of their facilities.
The radiation protection paradigm is a model for keeping people safe from radiation injury or harm, which in this case could be caused by NPP operations. It is founded on fundamental principles, which in turn are based on solid ethical doctrines, and built up into a system of radiation protection. The primary aim is to achieve an appropriate level of protection for people and the environment against the detrimental effects of radiation exposure without unduly limiting the desirable human actions that may be associated with such exposure, one of these actions being the generation of nuclear electricity. The system includes a classification of feasible exposure situations, a characterization of type of exposures and a scheme for controlling such exposures.
It is to be noted that radiation protection concerns all exposures to radiation from any source, regardless of its size and origin. However, the restraint of exposures can apply in their entirety only to situations in which either the source of exposure or the pathways leading to the doses received by individuals can be controlled by some reasonable means. Some exposure situations are excluded from radiological protection legislation, usually on the basis that they are unamenable to control with regulatory instruments (e. g., some exposure to natural sources), but this is not the case for exposure situations from NPPs which are unexceptionally included in regulations. However, some exposure situations at NPPs may be exempted from some radiation protection regulatory requirements whenever such controls are regarded as unwarranted, e. g. because the activity of the sources and the exposure they deliver are minute. ICRP has issued comprehensive recommendations for exclusion and exemptions (ICRP, 2007b). Remarkably, international agreements have been reached for exemption values in all commodities (IAEA, 2004b, 2004c), for drinking water (WHO, 2004) and for foodstuffs (CAC, 2006).
When a nuclear accident involves a large amount of radioactive aerosols, the subsequent fallout may contaminate the soil and water of affected areas. In this case, public authorities should implement specific protective measures, to protect the public in accordance with international standards, from contamination through foodstuff and water consumption and inhalation of airborne aerosols deposited in soil. It is likely that these actions would have to be continued for a long period. Management of these situations is usually beyond the scope of the nuclear emergency plans, because they could involve the intervention of a wide range of government institutions and require special political and economic decisions.
Lessons learned from the aftermath of the Chernobyl accident show that a relevant fraction of the total dose produced by a large nuclear accident arises from chronic exposure. Chronic exposure is mainly produced by direct exposure to soil contamination, contaminated food consumption and inhalation of radioactive airborne materials. Reducing long-term exposure could require implementation of hard countermeasures such as the longterm health care of victims, modification of agricultural practices and strict control of foodstuffs, and relocation of the population living in affected areas. Putting these countermeasures into practice requires spending large amounts of resources and can produce significant social and psychological effects on the affected population. Recent studies carried out in the region affected by the Chernobyl accident show that training the population to live with enhanced levels of radioactivity can help them to reduce the social and physiological effects and contribute decisively to normalizing the situation. The aftermath of the Chernobyl accident shows also that the efficient implementation of adequate countermeasures in the early emergency phase can reduce some long-term health effects such as thyroid cancer produced by inhalation and ingestion through milk of radioactive iodine.
It is important that all types of radioactive waste in a country are considered when the policies and strategies are developed. Most countries operating a nuclear power plant or considering introducing nuclear power are likely to also have radioactive waste from non-power applications of nuclear technology, e. g. from the use of radioisotopes in medicine and research or from operating research reactors. Although the volumes of waste from such applications normally would be smaller than from nuclear power production, they often have special characteristics that need to be considered.
As has been noted above, the present practice for reprocessing companies is to return the waste separated during the reprocessing to the country of origin, which thus needs to be considered in the planning if the reprocessing route is followed. Also the other steps in the fuel cycle will generate some radioactive waste that needs to be taken care of, e. g. mill tailings from uranium mining, depleted uranium from uranium enrichment and ILW from MOX fabrication. These wastes are normally kept by the supplier. In the case of depleted uranium they are seen as a resource for future use in fast neutron reactors. If a country develops its own fuel cycle capacity, the waste also needs to be considered in the national strategy.
Table 15.2 provides cost data on the construction of a hypothetical nuclear power plant, and lays out a few commonly used but very different methods for quoting these same costs. The example demonstrates a large disparity of quotations, even when the underlying plant and cost data are the same.
In the example, construction is planned to occur over a five-year period running from 2014 through 2018, so that the plant is ready for grid connection at the start of 2019. The utility receives an offer from a vendor for the construction of the nuclear island and turbine-generator unit under an EPC contract. Rows [3] and [4] of Table 15.2 show a typical construction cost schedule. The vendor’s total EPC OC quoted in 2010 prices and exchange rates is $3500 per kW(e) or $3.5 billion for a 1000 MW NPP.
Lines [5]—[11] show how the cost for the same plant is typically quoted by a utility as it seeks approval for the plant (in regulated markets) or finance and equity partners (in deregulated markets). Line [5] is the vendor’s quoted EPC OC cost, but these figures have been adjusted for inflation (here assumed to be 3% per year) so that each year’s figure reflects the expected nominal expenditure in that year. Line [6] shows the owner’s costs, i. e., the balance-of-plant, contingency and other costs that the utility has to cover out of its own pocket, in addition to the vendor EPC costs. The owner’s costs shown in line [6] are taken at 20% of the EPC OC figures of line [5].
Line [7] shows the cost of transmission system upgrades which are assumed to be necessary to deliver electricity to the grid once the hypothetical plant is completed at the end of 2018. Line [8] is the sum of lines [5], [6] and [7]. This total cost, which is exclusive of IDC, amounts to $5520 per kW(e) and serves as the basis for the IDC calculations in line [9] assuming a weighted average cost of capital (WACC) of 12%.
Line [10] shows the total costs as expended, inclusive of IDC. Line [11] accumulates total annual costs. By the end of 2018, when plant construction is completed and ready for grid connection, this total cost, inclusive of IDC, is $6930 per kW(e).[95] This is almost twice the vendor’s EPC OC of $3500 per kW(e). The difference between the two estimates is merely a question of the method of quotation, i. e., of what is in and what is out and how the dollar expenditures are denominated, whether in 2010 dollars or in nominal dollars (dollars as expended). If expressed in dollars at 2010 prices, i. e., what the plant would cost at the planning stage, the nominal total of $6930 corresponds to $5752 per kW(e). In contrast, if expressed in 2019
Notes: All figures in $/kW. Example assumes a total EPC overnight cost of $3500 owner’s cost and an allowed capital recovery charge (or WACC) of 12%.
Rows [ 1 ]—[ 15], columns [A]—[E]:
[3] Rate of expenditures is given.
[4] = [3] * $3500
[5] = [4] * (1.03)2 — 2010
[6] = 20% * [5]
[7] Transmission expenditures are given
[8] = [5] + [6] + [7]
[9] [9B] = [ 11 A] * 12% + 0.5 * [8B] * 12% and so on.
Source: adapted from Du and Parsons (2009).
prices, i. e., when the plant starts generating revenue, the cost is $7288 per kW(e).
A structured approach as outlined above allows a better comparison of cost estimates from different sources. However, it requires additional information than is commonly contained in media reports, utility or government announcements. Irrespective of the level of information available, it can help to identify inconsistencies in the quotations or define the set of common cost components upon which consistent comparisons can be made.
An even more transparent approach is the use of harmonized boundaries and assumptions. This not only facilitates comparisons of the costs of different nuclear power projects but also compares nuclear power with alternatives. The recent OECD report Projected Costs of Generating Electricity (NEA and IEA, 2010) followed the harmonized approach. Despite the harmonization, the report presents nuclear OC between $1560/kW(e) and $5860/kW(e) — a much wider range than five years ago — which shows continued uncertainty about nuclear power OC. Altogether 14 countries, all of which operate nuclear power plants, and two industrial associations contributed data for a total of 20 prospective nuclear projects (see Fig. 15.10). At the lower end of the OC estimates are China, Japan, Korea and Russia, i. e. countries with ongoing construction experience. At the higher end, OC
6000
І5, 2000
‘с
CD
>
О
1000
15.10 Expected overnight cost of nuclear power plants (NEA and IEA, 2010).
often reflect FOAK costs — either truly for the first construction of a design never built before (e. g., the EPR at Olkiluoto in Finland), for construction in a region or country without nuclear power (e. g., UAE or Vietnam) or for new construction in countries where active nuclear power construction stopped decades ago (e. g., USA, Belgium, Switzerland or UK).
Regulation 5 of the Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009 prescribes the various documents and information that must accompany applications for orders granting development consent. Significantly, this includes the production of an environmental statement (and any relevant scoping and screening opinions) pursuant to the Infrastructure (Environmental Impact Assessment) Regulations 2009. The IPC/MPIU is compelled by Regulation 3(2) and (3) not to grant development consent unless it has first taken the environmental information into consideration and stated in its decision that it has done so. The requirement to furnish an environmental statement with the application obliges applicants to advertise and consult on the environmental statement at the pre-application stage in conjunction with their general consulting obligations. In a similar vein, Part 51 of the United States Regulatory Commission’s NRC Regulations (10 CFR Part 51) also prescribes detailed information on the requirements and content of environmental impact assessments for US new build.
Section 55(2) of the PA 2008 requires the IPC/MPIU to decide whether or not to accept applications for further examination within 28 days of their receipt. Once accepted, the IPC/MPIU must invite affected local authorities to submit local impact reports detailing the likely impact of the proposed development on the authority’s area. This is another opportunity for the environmental impacts to be considered and local issues adequately addressed. As Tromans notes (2010, p. 145), ‘there will be an important relationship to be worked out between the local impact report and the environmental statement produced by. . . the applicant. The impact report may present a quite different perspective on what are regarded as likely and significant impacts’.
In 1950 the then Reactor Safeguards Committee under the old AEC prepared a report (AEC, 1950) proposing the creation of a so-called exclusion radius around a nuclear reactor where residences were not permitted. It was also proposed that such a radius, measured in miles, be 1/100 of the square root of the reactor power measured in thermal kilowatts, i. e.
R (miles) = ^W P (kW); the proposal was based on the assumption that
the reactor will undergo a reactivity excursion, melting the core and rupturing the coolant system with the fission products escaping freely to the environment. The application to such a rule of thumb to nuclear power plants designed in the 1960s and 1970s led to an unacceptably large exclusion radius.
After realizing that the proposed rule of thumb was not appropriate to the many medium-sized demonstration reactors under consideration and after accepting the principle that reactor containment was better than isolation, in 1959 the AEC published in the Federal Register new proposed site criteria. The new site criteria maintained the concept of exclusion radius, now called exclusion distance, which depended not only on thermal power but also on the design features, mainly the inclusion of a containment system, and the site characteristics. For the large power reactors then considered the accepted exclusion radius varies from xh to % mile. It was also determined that beyond the exclusion radius population density should be small and there should be no large cities within 10 to 20 miles. In this preliminary document the main site parameters based on seismology, meteorology, geology and hydrology were also defined and considered.
After several intermediate steps, such rules were perfected and consolidated in a new document published in 1962 under the title 10 CFR Part 100 Reactor Site Criteria, which has been maintained up to now. The new document consolidated the concept of exclusion area and created two additional concepts: a low population zone surrounding the exclusion area containing residents ‘the total number and density of which are such that there is a reasonable probability that appropriate protection measures could be taken in their behalf in the event of a serious accident’, and a population centre distance determining the minimum acceptable distance to ‘the nearest boundary of a densely populated center containing more than about 25,000 residents’.
Methods to determine the corresponding radius and distances were also published by reference to a Technical Information Document (TID-14844) developed by DiNunno and co-workers (DiNunno et al., 1962) based on a hypothesis regarding the consequences of the maximum credible accident, a concept that was introduced in 1959 by Dr Clifford Beck, a notorious regulator within the AEC, and on limiting radiation doses to the population (Beck, 1959). These ideas and concepts are maintained today and have had a deep influence in other countries; moreover they constitute one of the pillars for the safe design of most of the currently operating reactors. A full account of these historical developments has been published by Okrent (1981).
In the CC document, the owner shall request the bidder to submit a payment schedule, clearly indicating the amount of the advance payment (if so requested by the bidder) and of the payments linked to the fulfilment of each milestone listed in the payment schedule. The owner may wish to specify in the BIS project milestones that should be complied with as a minimum to receive partial payment. Payment milestones should be linked to a representative delivery or measurable project progress, and should also ensure the owner that payments made are commensurate with actual project progress.
Payments to be made upon fulfilment of a milestone should be differentiated according to whether they are made in local or foreign currency.
Finally, the owner should establish in the DC document of the BIS all the detailed contractual conditions regarding payment, such as payment currency, advanced payment guarantee, criteria to be applied in case of delayed payment, failure to make a payment by the owner, disputes concerning payment, invoicing rules, form and place of payment after invoicing, and setting-off.