RD&D-Programme 2004 - SKB

Overall system optimization is handled within the framework of the concept of system analysis.
The purpose of system analysis is to evaluate how alternative ways of designing, building
and operating a facility or subsystem affect other facilities or subsystems as well as the whole
system. System analysis thereby also provides the necessary overview of how different
decisions and choices affect the degrees of freedom in the whole system.
The effects of disturbances and mishaps are also analyzed. The baseline from which the
consequences of variations, disturbances or mishaps are measured is the applicable reference
design and timetable. The results of the system analysis are vital for being able to choose design
alternatives and justify these choices.
The level of detail in the system analysis is limited in that only variations and disturbances
in one facility or subsystem that have effects on another facility or subsystem are studied.
Questions where alternatives, choices of solutions, disturbances etc only concern individual
facilities are handled as components in the design of the facility in question. Due to this
limitation, the deep repository’s capacity to receive canisters for deposition is, for example, a
question for system analysis, while the mode of transporting canisters down into the repository
is not.
Important system variants that will be dealt with in future system analyses are:
• Siting alternatives for the deep repository (Forsmark or Simpevarp/Laxemar).
• Siting of the encapsulation plant (reference at Clab, alternative Forsmark).
• Total fuel quantity (reference 40 years’ operation of the NPPs, alternative 60 years’
operation).
• Deposition method (reference KBS-3V, alternative KBS-3H).
• Retrieval (reference no retrieval, alternative retrieval after initial operation).
• Closure (reference closure shortly after end of operation, alternative extended period with
open repository).
Examples of disturbances that will be analyzed are stoppages in different parts of the handling
chain. Studied variants and disturbances are evaluated with respect to the aforementioned
general criteria. Other comparison factors may also be considered, such as system availability
as well as safeguards and physical protection. The cost aspects of different variants of system
design and implementation are studied within the framework of the ongoing Plan work and are
therefore not included in system analysis.
There are certain mutual system dependencies between the programmes for spent nuclear fuel
and LILW. The system analyses for the nuclear fuel system will therefore also shed light on the
consequences of design variants for the LILW system.
Accounting prior to permit applications
In conjunction with the integrated account of method, site selection and programme prior to the
site investigation phase (RD&D-K), SKB presented a system account of the KBS-3 method and
a consequence analysis of the zero alternative, defined as continued storage in Clab.
During the remainder of the site investigation phase, accounts of revised system analyses are
planned on two occasions. The first, called Sysinka, will be included in the supporting material
for the permit application for the encapsulation plant. Aside from Clab and the encapsulation
plant, the material available regarding the deep repository will then be presented. The second
system analysis, called Sysdjup, will be appended in a corresponding manner to the application
for the deep repository, whereby the complete system with selected sitings is described.
370 RD&D-Programme 2004