RD&D-Programme 2004 - SKB

20 Biosphere
SKB’s biosphere programme for the coming six years was described in RD&D-Programme
2001. After nearly half the time it can be noted that the programme has largely proceeded
according to plan and that the research has had the desired results. More than 40 reports, ten
articles in international scientific journals, two doctoral theses and two licentiate theses have
been published during the period. The ambition stated in RD&D 2001, including increased
publication in international journals, has been realized.
A unique site investigation programme for the biosphere was started and a new organization for
site investigation was created during the period. The research programme has participated with
resources, experts and development of methods to make this possible. A breakthrough was also
made during the period in the development of new, modern tools for biosphere modelling within
the safety assessment. SKB is thereby equipped to conduct safety assessments with effective
tools and relevant data.
The coming period will be characterized by extensive efforts when it comes to analysis of
site-specific data, as well as several major safety assessments. The long-term biosphere research
is well designed to contribute methodology and data for these tasks, but is also prepared to
conduct targeted research to solve any new problems that may emerge.
Interest on the part of Swedish and international research groups working with radioecology and
environmental problems will probably increase during the upcoming period as new findings and
methods are published by SKB. This will stimulate discussion while leading to further publication
and dissemination of the results in international forums.
20.1 State of the biosphere
The surface ecosystems or the biosphere are the part of the earth in which most living
organisms – animals, plants and humans – live. The consequences of a possible release from
the deep repository in the form of radiation dose to humans and other organisms are seen in the
biosphere. Calculations of the flux of radionuclides in the biosphere and the dose consequences
this leads to are therefore an important part of a safety assessment. The calculated consequences
are used to show whether the authorities’ requirements on safety and limit values expressed
in doses and risk are met, and to compare different facilities, technical solutions or sitings.
Credible calculations require a realistic description of events and processes in the biosphere
with reasons why certain processes are important and why others can be ruled out. The states
of the surface ecosystems also comprise chemical (salinity, oxygen content), hydrological
(water balance) and geological (shoreline displacement) boundary conditions for processes
in the geosphere. These conditions are climate-dependent.
In the site investigations and subsequent siting of the deep repository for spent nuclear fuel,
consideration must be given to how the activities directly affect the surface ecosystems.
The biosphere will also be included in any monitoring of the repository area, and during the
monitoring period the surface ecosystems are expected to change naturally. Good knowledge
of the original state of the ecosystems and continuous follow-up of natural changes are required
to be able to distinguish natural changes from the effects of a repository. All of this demands
early and thorough investigations of the biosphere on a candidate site.
The overall goal of the biosphere programme is to describe, based on modern scientific
knowledge, the most important processes in the biosphere from a radiological point of view
and to provide sufficient scientific support to assess the environmental consequences of
constructing and operating a repository.
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