Browse by: "C"

While there is a growing interest in the deployment of small modular reactors (SMRs) as a promising option to help mitigate climate change, further international efforts are needed to accelerate the development and safety demonstration of the innovative technologies that are being considered for many of these SMRs. This publication presents the actions taken by the NEA Committee on the Safety of Nuclear Installations (CSNI) and its expert group on SMRs to define the areas of future CSNI research and safety assessment work needed to support sound safety demonstrations for SMRs. The proposed activities address four areas: support for regulatory harmonisation, common safety issues of interest for different designs, experimental campaigns, and benchmarking for computer code validation and verification.

This study assesses the competitiveness of nuclear power against coal- and gas-fired power generation in liberalised electricity markets with either CO2 trading or carbon taxes. It uses daily price data for electricity, gas, coal and carbon from 2005 to 2010, which encompasses the first years of the European Emissions Trading System (EU ETS), the world’s foremost carbon trading framework. The study shows that even with modest carbon pricing, competition for new investment in electricity markets will take place between nuclear energy and gas-fired power generation, with coal-fired power struggling to be profitable. The outcome of the competition between nuclear and gas-fired generation hinges, in addition to carbon pricing, on the capital costs for new nuclear power plant construction, gas prices and the profit margins applied. Strong competition in electricity markets reinforces the attractiveness of nuclear energy, as does carbon pricing, in particular when the latter ranges between USD 40 and USD 70 per tonne of CO2. The data and analyses contained in this study provide a robust framework for assessing cost and investment issues in liberalised electricity markets with carbon pricing.

This document contains a compilation of consensus guidance for approval of long-term operation of nuclear power plants. This guidance is presented as fundamental and key principles that should govern decisions on authorisation for long-term operation. These principles allow for differences in national regulatory strategies and expectations while ensuring that safe performance can be achieved in long-term operation.

This volume is the 13th in the OECD Nuclear Energy Agency (NEA) “Chemical Thermodynamics” series. It is the first part of a critical review of the thermodynamic properties of iron, its solid compounds and aqueous complexes, initiated as part of the NEA Thermochemical Database Project Phase III (TDB III). The database system developed at the OECD/NEA Data Bank ensures consistency not only within the recommended data sets of iron, but also among all the data sets published in the series. This volume will be of particular interest to scientists carrying out performance assessments of deep geological disposal sites for radioactive waste.

This is Volume 13b in the OECD Nuclear Energy Agency (NEA) “Chemical Thermodynamics” series. It is the second part of a critical review of the thermodynamic properties of iron, its solid compounds and aqueous complexes, initiated as part of the NEA Thermochemical Database Project Phase IV (TDB IV), and a continuation of Part 1, which was published in 2013 as volume 13a. The database system developed at the NEA Data Bank ensures consistency not only within the recommended data sets of iron, but also among all the data sets published in the series. This volume will be of particular interest to scientists carrying out performance assessments of deep geological disposal sites for radioactive waste.

This volume provides a state-of-the-art report on the modelling of aqueous-solid solution systems by the combined use of chemical thermodynamics and experimental and computational techniques. These systems are ubiquitous in nature and therefore intrinsic to the understanding and quantification of radionuclide containment and retardation processes present in geological repositories of radioactive waste. Representative cases for study have been chosen from the radioactive waste literature to illustrate the application of the various approaches. This report has been prepared by a team of four leading experts in the field under the auspices of the OECD/NEA Thermochemical Database (TDB) Project.

This volume is the eleventh in the OECD Nuclear Energy Agency (NEA) “Chemical Thermodynamics” series. It is based on a critical review of the thermodynamic properties of thorium, its solid compounds and aqueous complexes, initiated as part of the NEA Thermochemical Database Project Phase III (TDB III). The database system developed at the OECD/NEA Data Bank ensures consistency not only within the recommended data sets of thorium, but also amongst all the data sets published in the series. This volume will be of particular interest to scientists carrying out performance assessments of deep geological disposal sites for radioactive waste.

The Chemical Thermodynamics of Tin is based on a critical review of the thermodynamic properties of tin, its solid compounds and aqueous complexes, carried out as part of NEA Thermochemical Database Project Phase III (TDB III). The database system developed at the OECD/NEA Data Bank ensures consistency not only within the recommended data sets of tin, but also among all the data sets published in this series. This volume will be of particular interest to scientists carrying out performance assessments of deep geological disposal sites for radioactive waste.

The international radiological protection community performed a major status review of the situation around the damaged Chernobyl reactor on the 10-year anniversary of the accident. Since then, studies of the accident site and the contaminated territories continue to be undertaken, which have yielded new scientific results and highlighted important social and health aspects. This report is a complete update of the NEA’s earlier publication, Chernobyl: Ten Years On. In particular, it offers the reader the most recent information on the significant new experience gained in the areas of emergency management, long-term environmental behaviour of radioactive materials and health effects.

Communication  has  a  specific  role  to  play  in  the  development  of  deep  geological  repositories.  Building trust  with  the  stakeholders  involved  in  this  process,  particularly  within  the  local  community,  is  key  for effective communication between the authorities and the public. There are also clear benefits to having technical experts hone their communication skills and having communication experts integrated into the development process. This report has compiled lessons from both failures and successes in communicating technical information to non-technical audiences. It addresses two key questions in particular: what is the experience base concerning the effectiveness or non-effectiveness of different tools for communicating safety case results to a non-technical audience and how can communication based on this experience be improved and included into a safety case development effort from the beginning?

Nuclear accident risks are raised frequently in discussions of the acceptability of nuclear power generation, often framed in the context of the Three Mile Island and Chernobyl accidents. In reality, the safety record of nuclear power plants, by comparison with other electricity generation sources, is very good. This report describes how safety has been enhanced in nuclear power plants over the years, as the designs have progressed from Generation I to Generation III, and why it is important that safety remain the highest priority. This is illustrated by considering core damage frequencies and large radioactive release frequencies for each generation of nuclear power plants. It also compares severe accident data (those resulting in five or more fatalities) between different energy sources, both for immediate fatalities and for delayed (latent) fatalities, recognising that the latter data are often more difficult to estimate. Finally, it uses results of opinion surveys to analyse public confidence in nuclear operations and how this is correlated with trust in legislation and regulatory systems. It has been written for a general audience.

Establishing reliable computational methods and tools for radiation dosimetry is of great importance today because of the increased use of radiation in a number of areas of science, technology and medical applications. Fields concerned include radiation protection, radiation shielding, radiation diagnostics and therapy, radiobiology, biophysics and radiation detection. This series of lectures delivered by experts provides the content of these workshop proceedings. They are a valuable reference for those wishing to better understand the most advanced computational methods in radiation dosimetry.

A key challenge in the development of safety cases for the deep geological disposal of radioactive waste is handling the long time frame over which the radioactive waste remains hazardous. The intrinsic hazard of the waste decreases with time, but some hazard remains for extremely long periods. This report reviews the current status and ongoing discussions of this issue, addressing such issues as ethical principles, the evolution of the hazard over time, uncertainties in the evolution of the disposal system (and how these uncertainties themselves evolve), the stability and predictability of the geological environment, repository planning and implementation including regulatory requirements, siting decisions, repository design, the development and presentation of safety cases and the planning of pre- and post-closure institutional controls such as monitoring requirements.

The opening of energy markets is leading to increased competition, and the nuclear power industry must adapt if it is to meet this challenge. Internationally discussions are taking place among government authorities and electric utilities and vendors on how to deal with the rapid technical development and optimisation of nuclear fuel and its utilisation under new, more aggressive fuel management strategies. Improving reactor core monitoring systems is an important part of this process. Participants in a recent NEA workshop discussed how instrumentation, methods and models used in core monitoring can be validated or, if needed, improved and further developed to provide more reliable and detailed information on local power in the core and on other parameters indirectly affecting fuel duty. This book shows how the core monitoring system can be used to support reactor operation in normal and anticipated transient modes and to supply data used to derive initial key core parameters for transient and accident analysis.

The nuclear sector has in recent years been placing increasing attention on the need to better understand variations between cost estimates for the decommissioning of nuclear power plants, as well as the relationship between estimated and actual costs, and the apparent escalation of these costs. Building on previous work by the Nuclear Energy Agency, Cost Benchmarking for Nuclear Power Plant Decommissioning examines approaches and methods for the benchmarking of nuclear power plant decommissioning costs. Particular focus is given to identifying key factors, drivers and constraints to implementing cost benchmarking. These factors are addressed from a broad range of perspectives in order to develop a roadmap for implementation that will garner sufficiently broad support from a wide base of interested stakeholders. The report also identifies a number of perceived barriers that may impede the implementation of benchmarking for decommissioning. Co-ordinated efforts and further analysis will be needed to help remove these barriers.

This report is based on a study carried out by the NEA Decommissioning Cost Estimation Group (DCEG) on decommissioning cost elements, estimation practices and reporting requirements. Its findings indicate that cost methodologies need to be updated continuously using cost data from actual decommissioning projects and hence, systematic approaches need to be implemented to collect these data. The study also concludes that changes in project scope may have the greatest impact on project costs. Such changes must therefore be identified immediately and incorporated into the estimate. Finally, the report notes that more needs to be done to facilitate the comparison of estimates, for example by providing a reporting template for national estimates.