The 12th International Conference on Environmental ... - Events

Session 51-52 Abstracts
results on helium diffusion obtained by two different studies: on 244Cm-doped glass and on glasses implanted with helium ions.
Helium diffusion coefficients were determined by modeling the experimental results obtained. <strong>The</strong> physical characteristics which
one can withdraw from each technique regarding helium diffusion were underlined. <strong>The</strong> results were compared also with those
obtained on damage and undamaged samples from the literature to assess the specific effect of glass damage on helium diffusion.
7) UNDERSTANDING POTENTIAL RELEASE MECHANISMS OF VOLATILE RUTHENIUM
DURING THE VITRIFICATION OF HIGH LEVEL WASTE - 16288
Chris Brookes, Sellafield Ltd (UK); Yvonne Lawson, Mark Sarsfield, National Nuclear Laboratory (UK);
Carl Steele, Sellafield Ltd. (UK)
In the U.K., High Level Waste from reprocessing operations is vitrified at the Sellafield Waste Vitrification Plant (WVP). A
small number of the nuclides present in the waste have the potential to volatilize during vitrification. In order to prevent release of
any radionuclides to the environment it is important to understand the mechanisms by which volatilization may occur and to have
suitable controls in place. One element of particular concern is ruthenium, formed during the fission of nuclear fuel, which has the
potential to form gaseous species such as RuO4 during the vitrification process and whose behavior must therefore be understood
in order to underpin the safe operation of WVP.
SESSION 52 - A SYNOPSIS OF KNOWLEDGE MANAGEMENT SYSTEMS
1) USE OF THE SAFETY CASE TO FOCUS KMS APPLICATIONS - 16348
Hideaki Osawa, Kazumasa Hioki, Hiroyuki Umeki, Japan Atomic Energy Agency (Japan);
Hiroyasu Takase, Quintessa Japan, (Japan); Ian McKinley, McKinley Consulting (Switzerland)
<strong>The</strong> safety case, as defined in Japan, is an integrated set of arguments to show that a repository is sufficiently safe during both
operational and post-closure phases. It explicitly includes the findings of a safety assessment and a demonstration of confidence in
these findings. It is developed in a stepwise manner, with provisional cases used to support decisions at major project milestones.
Social acceptance is acknowledged to be critical and hence a safety case includes not only technical components, but also the arguments
required to explain fundamental issues to all key stakeholders.
In the JAEA KMS project, the safety case has been found useful as a framework that allows all supporting R&D to be seen in
the context of its applicability. Various tools have been examined to develop associated argumentation models and they have been
seen to provide an overview that is valuable to both the users and producers of knowledge. <strong>The</strong> paper will review progress to date
in this work, with illustrative examples of argumentation networks and an outline of future developments and challenges.
2) PRACTICAL APPLICATION OF THE KMS: 1) TOTAL SYSTEM PERFORMANCE ASSESSMENT - 16349
Hitoshi Makino, Kazumasa Hioki, Hiroyuki Umeki, Japan Atomic Energy Agency (Japan);
Hongzhi Yang, Hiroyasu Takase, Quintessa Japan (Japan); Ian McKinley, McKinley Consulting (Switzerland)
Comprehensive total system performance assessment (PA) is a key component of the safety case. Within this PA there are a
number of tasks that reuse specific models and datasets, together with associated knowledge base for the disposal system considered.
<strong>The</strong>se are tasks where recent developments in the JAEA KMS can lead to optimisation of procedures. This paper will outline
the reformulation of PA as a Knowledge Management (KM) task, discuss application of knowledge management technologies to
PA tasks, and illustrate how these can be handled electronically in a Performance assessment All-In-one Report System (PAIRS)utilizing
hyperlinks and embedded tools to minimise duplication of material, ease Quality Assurance (QA) and facilitate the regular
updating required in the Japanese programme.
3) PRACTICAL APPLICATION OF THE KMS: 2) SITE CHARACTERISATION - 16355
Takeshi Semba, Hideaki Osawa, Kazumasa Hioki, Japan Atomic Energy Agency (Japan);
Shoko Tachibana, Hiroyasu Takase, Quintessa Japan (Japan); Ian McKinley, McKinley Consulting (Switzerland)
<strong>The</strong> characterisation of potential repository sites is one of the most resource-intensive and politically-sensitive tasks facing the
Japanese geological disposal programme. This work will produce huge volumes of information that must be correlated, quality
assured, integrated, analysed, documented and archived in a rigorous and efficient manner (a process often referred to as geosynthesis).
While some of this work involves rather routine data handling that may be easily automated, much of it requires input of
tacit knowledge which involves the experience of expert staff. In particular, planning and managing the characterisation programme
results in challenges due to the inherent uncertainty in site understanding and the inevitable surprises that will occur.
To provide support for the Japanese implementer (NUMO), which may need to run several field programmes in parallel and
also the regulator, which is supposed to follow these and provide input for key decisions, JAEA is attempting to capture both Japanese
and international geosynthesis experience within a KMS framework (termed ISIS). Although a hybrid system that combines
smartsoftware with human experts is required, the aim is to capture expert knowledge within expert systems to the maximum extent
practicable. Initial tests, based mainly on field work carried out by JAEA at the sites of the Mizunami and Horonobe underground
research laboratories, have utilised expert systems as modules in a blackboard systemapproach to planning or implementing the
processing of field data. Examples will be presented of sub-systems where this approach has already been demonstrated and perspectives
for more extensive application to integrated geosynthesis management will be discussed.
4) CHALLENGES FOR THE JAEA KMS: FOSTERING INVENTIVE DESIGN AND PROBLEM SOLVING - 16351
Hitoshi Makino, Kazumasa Hioki, Hiroyuki Umeki, Japan Atomic Energy Agency (Japan); Shoko Tachibana, Hiroyasu
Takase, Quintessa Japan (Japan); Ian McKinley, McKinley Consulting (Switzerland)
<strong>The</strong> Knowledge Management System by Japan Atomic Energy Agency (JAEA KMS) is being developed to be flexible and
able to respond to potential changes of boundary conditions. On a shorter timescale, the KMS must encourage flexibility in the
methodology used for carrying out and presenting performance assessments. This is closely linked to development of advanced
repository concepts; considering the requirements for a safe and practical repository tailored to specific site conditions, which
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