The 13th International Conference on Environmental ... - Events

Abstracts
Nuclear Reactors”, was amended in 2007 to address the safety of geologic disposal of high-level radioactive waste. NISA
announced its involvement or supervision not only for the licensing application but during the site selection process. Two
major research areas required by NISA have been identified: studies to review the validity of preliminary survey results
during the site selection, and studies to review the safety assessment for a licensing application. <strong>The</strong>se research areas are
aimed at 1) developing “safety indicators” to judge the adequacy of site investigation results presented by the operator, 2)
compiling basic requirements of safety design and safety assessment needed to make a technical evaluation of the license
application, as well as developing safety indicators for objective evaluation, and 3) developing an inde-pendent safety
assessment methodology. In addition, NISA plans to periodically issue the report, “<strong>The</strong> Regulatory Research Report on
Geological Disposal” consistent with the operator’s technical report sched-ule. This report would be intended to confirm
the regulatory status of the program as well as strengthen-ing the competence of NISA as a regulatory body. JNES
launched safety studies on geological disposal in its establishment year in 2003. JAEA and AIST joined as regulatory
support research institutes in 2005. In October 2007, the three parties signed an agreement of cooperative study on
geological disposal, which enhanced joint studies, as well as exchanges of staff, data, and results. One of the ongoing
joint studies has been aimed at investigating regional-scale hydrogeological modeling using JAEA’s Horonobe
Underground Research Center. <strong>The</strong> three parties have begun to discuss expanding the joint studies and the agreement
areas in response to the new five-year re-search plan.
3) 40280 – Recent Developments and Trends on Requirements Management Systems
Satoru Suzuki, Hiroyoshi Ueda, Kiyoshi Fujisaki, Katsuhiko Ishiguro, Hiroyuki Tsuchi, NUMO (Japan);
Stratis Vomvoris,Irina Gaus, Nagra (Switzerland)
Although the management of requirements for the development of geologic repository systems has been practiced in
all radioactive waste disposal programs from the beginning, the systematic management through IT-based requirement
management systems (RMS) has a younger history. Traditionally requirements have been gathered in various documents
and quite often the rationale for design choices is difficult to trace. Thanks to the development of RMS in other industries
(software development, aerospace), many radioactive waste disposal programs have recently been able to set-up and
tailor RMS to their needs quickly. In a recent international meeting, five radioactive waste disposal organizations
(NUMO/Japan; NAGRA/Switzerland; ONDRAF/NIRAS/Belgium; POSIVA/Finland and SKB/Sweden) have discussed
the status and developments of RMS in their respective programs. <strong>The</strong> majority have already implemented an IT-based
system, or, are testing and developing such systems. <strong>The</strong> level of detail of requirements depends on the stage of the
program. Those approaching the license application have integrated all components of the repository concept, including
the processes for the operational phase. It was recognized that the earlier you implement a systematic tracking of
requirements and the decisions taken to satisfy these requirements, the easier it would be to implement an RMS over the
whole duration of the geologic disposal program – in the order of 100 years. <strong>The</strong> documented transition from the general
requirements (highest level) to the lower level ones – especially those related to the repository system concept or its
components – can be then used to enable the assessment of potential changes at future stages of the system. Even if the
host rock or, the repository concept has not been selected, a ‘dry’ run with assumed conditions can be very elucidating of
the most useful set-up of the RMS. Requirements management is closely associated with the quality management system.
Combining requirement and decision-tracking has been expressed as an explicitly goal for some programs. Caution was
expressed regarding the expectations for the RMS being developed. <strong>The</strong>re is a risk that such systems are perceived as
expert systems that can derive decisions, which then will be unquestionably accepted. It is nevertheless recognized that
they can be of great help in communicating with the various stakeholders and with relative ease demonstrating how their
requirements have been considered and satisfied with the proposed repository systems. Further efforts need to be
undertaken to integrate the requirement management systems, and the processes that they represent, in the day-to-day
operations of the organizations. Different organizational schemes are being considered, for example, the composition of
the team that defines the requirements at the various levels and the function of its members within the technical and
scientific program of the waste disposal organizations. First positive experiences of the latter were reported.
4) 40228 – Development of Requirements Management System of NUMO and practical experience with
development of the database contents
Satoru Suzuki, Hiroyoshi Ueda, Katsuhiko Ishiguro, Hiroyuki Tsuchi, Kiyoshi Fujisaki, NUMO (Japan);
Kiyoshi Oyamada, JGC Corporation (Japan); Shoko Yashio, Obayashi Corporation (Japan)
Decision-making and work activities in the geological disposal program need to be implemented in such a way as to
fulfill various requirements such as safety, practicality, quality and socio-economic aspects. Since a stepwise approach is
applied for implementing the program, the number, weighting and specific nature of the requirements will change
depending on the premises and constraints in each stage of implementation. Requirements management with a long-term
perspective is therefore required for consistent implementation of the program. NUMO has developed a requirements
management (RM) methodology that is suitable for the long-term, stepwise disposal program in Japan, as well as a
supporting requirements management system (RMS) tool. <strong>The</strong> basic concept of the RMS was already presented at the
last ICEM 2009. In this presentation, we will focus on practical experience with development of the database content for
the RMS. <strong>The</strong> RM methodology was first applied in the HLW repository design work. Requirements for repository
design were considered primarily from the viewpoint of post-closure safety and engineering feasibility. <strong>The</strong> repository
design requirements are structured hierarchically to those assigned to the ‘post-closure safety concept’, the ‘required
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