RD&D-Programme 2004 - SKB

Programme
Decay heat measurements with the new measurement equipment will be conducted in campaigns.
The first measurement campaign on Clab fuel has been initiated. A special database
has been established for storage and handling of the large quantities of measurement data. An
estimated 15–20 fuel assemblies will be measured each year at Clab. In parallel with the calorimetric
measurements, gamma measurements will be performed on the same fuel assemblies.
The intention is that the calculated decay heat output can be verified by gamma measurement
alone at the time of encapsulation, since calorimetric measurement is a time-consuming and
complicated process.
The results from each campaign will be evaluated carefully, in close cooperation with both
Swedish companies and Oak Ridge National Laboratory (ORNL) in the USA. Since November
2000, SKB has had a cooperation agreement in this area with UT-Battelle, which operates
ORNL.
An action plan will be prepared to describe what it would entail for the encapsulation process if
the verifying measurement of fuel done just before encapsulation were to show large discrepancies
in relation to the figures submitted by the nuclear power plant when the fuel was transferred
to Clab. It should be noted that encapsulation will continue for a long time after the nuclear
power plants have been shut down.
The plans of the nuclear power utilities include changes that may affect the fuel’s geometry and
source terms. This may affect the facilities and the transportation system. An inquiry has been
initiated to develop a long-term strategy for SKB.
8.1.2 Design and application
Design of the encapsulation plant is proceeding in steps. The ongoing design step corresponds
to the level of detail required in an application for a permit to build a plant. The design of an
encapsulation plant at Clab has previously been carried out to this stage /8-2/. The ongoing
design process is thus a revision where experience from the Canister Laboratory, changes in
the regulatory framework and technical progress are being incorporated in the design. Design
is taking place in close cooperation with SKB’s Finnish counterpart Posiva.
In order to design the plant, SKB has started a project and contracted a consultant for plant and
process design. Design is supplying supporting material for the system part in the preliminary
safety report as well as certain references to the report’s general section. Work on the general
section is being pursued separately. All safety-related supporting material will also be reviewed
independently by an organization with experience from similar nuclear assignments.
In parallel with the design of the encapsulation plant, an environmental impact statement (EIS)
is being prepared in a process called environmental impact assessment (EIA), an important part
of which is consultation with affected parties.
In addition to a preliminary safety report and an environmental impact statement, a safety
assessment of the long-term safety of the deep repository and a system analysis of KBS-3 will
also be appended to the application for a permit to build the encapsulation plant. This is shown
in Figure 8-3.
98 RD&D-Programme 2004