Abstract
Primary criteria for repository safety are commonly expressed in terms of risk or dose, and a biosphere model is required to evaluate the corresponding assessment endpoints. Even when other indicators are used to express the safety goals, a biosphere model is still needed in order to justify those indicators. In safety or performance assessments of a repository, the uncertainties in space and time for the different components of the repository system have to be considered. For the biosphere component, prediction of future human habits, in particular, is extremely uncertain. This is especially important in the assessment of deep geological disposal, which involves very long timescales, particularly for wastes containing very long lived radionuclides. Thus, the results of biosphere modelling should not be seen as predictions, but as illustrations of the consequences that may occur, should the postulated release occur today or under other conditions implied by the underlying biosphere model assumptions. Differences in biosphere modelling approaches arise because of differences in regulations, the nature of the wastes to be disposed of, disposal site characteristics, disposal concepts and purposes of the assessment. Differences in treatment of uncertainties can also arise. For example, if doses or risks are anticipated to be far
More>>
Dorp, F van
[1]
- NAGRA (Switzerland); and others
Citation Formats
Dorp, F van.
Interim report on reference biospheres for radioactive waste disposal.
Sweden: N. p.,
1994.
Web.
Dorp, F van.
Interim report on reference biospheres for radioactive waste disposal.
Sweden.
Dorp, F van.
1994.
"Interim report on reference biospheres for radioactive waste disposal."
Sweden.
@misc{etde_20100729,
title = {Interim report on reference biospheres for radioactive waste disposal}
author = {Dorp, F van}
abstractNote = {Primary criteria for repository safety are commonly expressed in terms of risk or dose, and a biosphere model is required to evaluate the corresponding assessment endpoints. Even when other indicators are used to express the safety goals, a biosphere model is still needed in order to justify those indicators. In safety or performance assessments of a repository, the uncertainties in space and time for the different components of the repository system have to be considered. For the biosphere component, prediction of future human habits, in particular, is extremely uncertain. This is especially important in the assessment of deep geological disposal, which involves very long timescales, particularly for wastes containing very long lived radionuclides. Thus, the results of biosphere modelling should not be seen as predictions, but as illustrations of the consequences that may occur, should the postulated release occur today or under other conditions implied by the underlying biosphere model assumptions. Differences in biosphere modelling approaches arise because of differences in regulations, the nature of the wastes to be disposed of, disposal site characteristics, disposal concepts and purposes of the assessment. Differences in treatment of uncertainties can also arise. For example, if doses or risks are anticipated to be far below regulatory limits, assessments may be based upon simplified and, necessarily, conservative biosphere models. At present biosphere models used to assess radioactive waste disposal show significant differences in the features, events and processes (FEPs) included or excluded. In general, the reasons for these differences have not been well documented or explained. Developments in radioecology have implications for biosphere modelling for radioactive waste disposal. In particular, after the Chernobyl accident, radioecological research has been significantly increased. Results of this research are already having and will continue to have a significant effect on biosphere modelling, for normal and accidental releases from nuclear installations, and also for waste disposal. For example, increased attention is being given to natural and semi-natural environments. Against this background, the primary objective of the BIOMOVS II Reference Biospheres Working Group is to establish a consensus on the development and application of a Reference Biosphere approach to the evaluation of long-term radiological consequences of solid radioactive waste disposal systems. The Working Group is expecting to provide: 1. A recommended methodology for biosphere analysis within the assessment of radioactive waste disposal, which is consistent for different types of radioactive waste and disposal concepts. This should include the justification, arguments and documentation for all the steps in the recommended methodology. A preliminary illustration of the approach is shown in the figure opposite. 2. An internationally developed and structured list of Features, Events and Processes (FEPs), which can be used to support the development of biosphere models for specific assessments. 3. Example(s) of how to apply the methodology. If these examples are developed in a suitably generic assessment context, they can be defined as generic 'Reference Biospheres' and their applicability and limitations should be identified. Such 'Reference Biospheres' could then be used e.g: (a) for generic site independent evaluation of disposal plans; (b) to provide sets of factors to convert geosphere release into doses or risks; (c) as 'stylised biospheres' (which might be defined as a biosphere which contains only the most essential FEPs); (d) as benchmarks for comparisons with other assessments, and (e) as sources of detailed information on biosphere modelling for waste disposal assessments. In order to complete an assessment of a particular site, there will not only be a need to take account of site specific issues, such as the geosphere-biosphere interface and the biosphere at the site, but also waste specific and acceptance criteria issues.}
place = {Sweden}
year = {1994}
month = {Oct}
}
title = {Interim report on reference biospheres for radioactive waste disposal}
author = {Dorp, F van}
abstractNote = {Primary criteria for repository safety are commonly expressed in terms of risk or dose, and a biosphere model is required to evaluate the corresponding assessment endpoints. Even when other indicators are used to express the safety goals, a biosphere model is still needed in order to justify those indicators. In safety or performance assessments of a repository, the uncertainties in space and time for the different components of the repository system have to be considered. For the biosphere component, prediction of future human habits, in particular, is extremely uncertain. This is especially important in the assessment of deep geological disposal, which involves very long timescales, particularly for wastes containing very long lived radionuclides. Thus, the results of biosphere modelling should not be seen as predictions, but as illustrations of the consequences that may occur, should the postulated release occur today or under other conditions implied by the underlying biosphere model assumptions. Differences in biosphere modelling approaches arise because of differences in regulations, the nature of the wastes to be disposed of, disposal site characteristics, disposal concepts and purposes of the assessment. Differences in treatment of uncertainties can also arise. For example, if doses or risks are anticipated to be far below regulatory limits, assessments may be based upon simplified and, necessarily, conservative biosphere models. At present biosphere models used to assess radioactive waste disposal show significant differences in the features, events and processes (FEPs) included or excluded. In general, the reasons for these differences have not been well documented or explained. Developments in radioecology have implications for biosphere modelling for radioactive waste disposal. In particular, after the Chernobyl accident, radioecological research has been significantly increased. Results of this research are already having and will continue to have a significant effect on biosphere modelling, for normal and accidental releases from nuclear installations, and also for waste disposal. For example, increased attention is being given to natural and semi-natural environments. Against this background, the primary objective of the BIOMOVS II Reference Biospheres Working Group is to establish a consensus on the development and application of a Reference Biosphere approach to the evaluation of long-term radiological consequences of solid radioactive waste disposal systems. The Working Group is expecting to provide: 1. A recommended methodology for biosphere analysis within the assessment of radioactive waste disposal, which is consistent for different types of radioactive waste and disposal concepts. This should include the justification, arguments and documentation for all the steps in the recommended methodology. A preliminary illustration of the approach is shown in the figure opposite. 2. An internationally developed and structured list of Features, Events and Processes (FEPs), which can be used to support the development of biosphere models for specific assessments. 3. Example(s) of how to apply the methodology. If these examples are developed in a suitably generic assessment context, they can be defined as generic 'Reference Biospheres' and their applicability and limitations should be identified. Such 'Reference Biospheres' could then be used e.g: (a) for generic site independent evaluation of disposal plans; (b) to provide sets of factors to convert geosphere release into doses or risks; (c) as 'stylised biospheres' (which might be defined as a biosphere which contains only the most essential FEPs); (d) as benchmarks for comparisons with other assessments, and (e) as sources of detailed information on biosphere modelling for waste disposal assessments. In order to complete an assessment of a particular site, there will not only be a need to take account of site specific issues, such as the geosphere-biosphere interface and the biosphere at the site, but also waste specific and acceptance criteria issues.}
place = {Sweden}
year = {1994}
month = {Oct}
}