Implementation of Safe Geological
Disposal in Japan
International Review of NUMO’s Approach andProgramme Readiness: 2010

Neil Chapman
Joonhong Ahn
Alan Hooper
Juhani Vira
Piet Zuidema(Switzerland)
(USA)
(UK)
(Finland)(Switzerland)

February 2011

Contents
1

Background and Context ..................................................................................................... 2

2

Procedure for the Review .................................................................................................... 2

3

General Comments ............................................................................................................. 2

4

NUMO’s Safety Strategy ..................................................................................................... 4

5

NUMO’s Project Plan .......................................................................................................... 7

6

Suggestions for NUMO’s Forward Planning ....................................................................... 87

Concluding Remarks ......................................................................................................... 10

8

The Review Panel ............................................................................................................. 10

1

1 Background and Context
1.1

NUMO was established in 2000 with the remit of implementing geological disposal of
HLW and, more recently, of TRU waste. It has been developing its strategic
approaches to geological repository siting, design and safety assessment, along withthe associated technologies for disposal, for the last ten years and has incorporated
input from R&D done by several other Japanese organisations. In a report published by
the Atomic Energy Commission of Japan it was suggested that NUMO should produce
a report (the ‘2010 Report’) of its progress in technical developments since 2000. In
addition to summarizing technical progress, NUMO decided to introduce its
implementation strategy for the geological disposal (GD) programme. This is a key
stage in the Japanese GD programme and an important assessment point for NUMO.
The government has consequently asked NUMO to commission a review of the 2010
Report by independent specialists. NUMO thus decided to organise the international
review of the 2010 Report alongside peer review by independent experts representing
the Atomic Energy Society of Japan (AESJ).

1.2

The independent international review has been carried out by a small Panel of experts
in geological disposal and its implementation, from Europe and the United States. The
Panel was asked to use its experience of other national programmes to assess
NUMO’s state of preparedness (in terms of both strategy and availability of appropriatetechnologies) for carrying out the initial stages of repository implementation. Thesestages involve assessing potential sites, carrying out site investigations, identifying
appropriate repository designs and safety concepts, assessing long term andoperational safety aspects, and selecting a site (or sites) which fulfil both the legal
requirements and NUMO’s requirements for HLW and TRU disposal.

1.3

In carrying out the review, NUMO has also asked the reviewers to provide any generaladvice that might assist in more effective programme implementation, as well as toadvise on a number of specific issues. This report contains the results of both thegeneral review and the advice provided by the Panel.

2 Procedure for the Review
2.1

The main ‘2010 Report’ is an extensive document of over 700 pages and, at the time of
the review, was only available in Japanese. The principal information evaluated by thereview Panel was a summary of the key strategic aspects of the main report, in English,
prepared specifically to assist the Panel. Consequently, it was important for thereviewers to get a broader picture of the scope and content of the main report so thatthey could be aware of the depth of the work that is reported on. The process thus
began with a two-day information meeting hosted by Nagra, in November 2010 in
Switzerland, where the reviewers were introduced to each of the main sections of themain report by NUMO staff and were able to ask questions, as well as provide initialcomments and views on the NUMO approach to the geological repository programme.

2.2

The English language summary was provided to the review Panel in January 2011.
The Panel reviewed the information contained in this document and met at Imperial
College in London, UK, on 16th and 17th February 2011 to discuss their views andprepare this review report. Members of NUMO staff also attended this meeting andwere able to provide further clarification of issues that the Panel discussed. The input
of NUMO staff to this report was confined to the correction of misunderstandings andfactual inaccuracies.

3 General Comments
3.1

The 2010 report describes an extensive and comprehensive programme of work
carried out by NUMO and other R&D organisations in Japan over the last decade. The
scope and content of the information introduced to the Panel are impressive and give a2good picture of NUMO’s capabilities and the thought that has gone into developing thepresent strategy.
3.2

Because the volunteer repository siting process in Japan could lead to potential
repository sites emerging in almost any part of the country (that is not excluded by theevaluation factors for qualification), NUMO has to keep open a range of possible
designs and approaches to site evaluation. Whilst this situation may be considered to
introduce poorly constrained uncertainties into programme management, it has notproved to be the case and is an area where NUMO is not alone: the UK is currently
moving forward successfully, with similar boundary conditions on its GD programme.
The reason that progress can be made is because the internationally recognised
approaches to ensuring the safety of GD facilities are at a more generic level and canbe applied as a framework for the overall concept of GD of HLW and TRU waste,
regardless of siting issues. This has allowed NUMO to make much progress, based
initially upon the milestone H-12 study, which will be sufficiently generic regardless of
how the volunteer programme develops. NUMO has thus developed a comprehensive,staged plan for development of Japan’s first geological repository by summarizing thelegal and regulatory frameworks and the technological state-of-the art.

3.3

The Japanese repository development programme is currently founded upon:•

the generic scientific feasibility of geological disposal that has been established(and is now accepted1) internationally by more than 30 years of intensive work
and was specifically demonstrated in Japan by the H-12 report, in 1999;•

a legal (and progressively developing regulatory) framework formulated by the
Nuclear Safety Commission, the Atomic Energy Commission and the Ministry of
Economy, Trade and Industry in the last decade;•the solicitation programme for volunteer municipalities and the proposal by thenational government to be a host community;•

cost-sharing schemes involving the national government and the electricity
companies;•

a range of fundamental scientific and engineering studies, including theUnderground Research Laboratories (URLs) in Horonobe and Mizunami.

NUMO has developed its programme by integrating these cornerstones into a detailed
plan. The main concepts and parts of the plan have been adopted from experiences inother countries and international generic developments. Based on the success of othernational programmes, it is reasonable to expect that the development could be
successfully carried out by NUMO within this plan, with timely revisions based upon
conditions specific to Japan (provisions for which are also included in the plan).
3.4

The information provided gives a clear impression that NUMO is well aware of the taskthat lies ahead and of all of the detailed activities that will need to be undertaken to
implement safe disposal. In the last ten years, together with the R&D organisations
NUMO has studied the tasks to be conducted and has also followed and contributed todevelopments at the international level. Not all the details of their work could be
described in the summary documentation, so it cannot be judged whether or not
NUMO’s preparations are complete, but the overall description allowed the Panel tograsp the enormous amount of work that underlies the report. The description of theimplementation of the disposal project is structured clearly and captured in a series ofactivities and steps to be conducted, as illustrated by the roadmaps.

3.5

NUMO has continued the development of the H-12 type repository concept and is now
able to present a number of possible designs for its practical implementation. Some of1

In November 2010, the proposed European Union (EU) Council Directive on the Management of Spent Fuel andRadioactive Waste stated that: “Following 30 years of research, it is broadly accepted at the technical level that deep
geological disposal represents the safest and most sustainable option as the end point of the management of highlevel waste and spent fuel considered as waste. Thus moving towards implementation of disposal should be
pursued.”3

the technical developments are based on international projects, but a lot of important
technical work has also been carried out in Japan. The Panel agrees that the H-12
concept is a reasonable basis for planning of the initial stages of the sitecharacterisation programme - and may turn out to be the best choice for the further
development as well. However, the Panel also points out that the implementation of a
H-12 type concept puts certain demands especially on the hydraulic and geochemical
conditions of the host rock. NUMO is aware of these constraints and envisages that, inthe end, the repository concept and design have to be adjusted to the specificconditions of the candidate sites. The Panel concurs, but, referring to the potential
siting environments in Japan, recommends that NUMO should also look to repository
concepts different from H-12. In some potential siting environments the H-12 concept
could even be greatly simplified because of benign host rock conditions. Narrowing
down to the most appropriate concept could be assisted by use of a requirements
management system (see further discussion on alternative concepts at 5.6).
3.6

NUMO points out that measures planned for operational safety have to be assessedvis-a-vis their potential impact on long-term safety. However, the issue is broader: allconstruction and operation practices (including any specific requirement to maintainretrievability) may have implications for long-term safety and, therefore, require an
assessment before adopting them.

3.7

An area of fundamental importance is evidence for the existence and maintenance of asound scientific and technical basis for the GD programme. This was emphasised in
the H-12 report, but NUMO was able to provide only limited information about how thisimportant aspect will be addressed. As discussed below, safety assessment provides
the means to assess the consequences of scientific and technical uncertainties and to
identify what further R&D may be required. Identification of appropriate R&D and ability
to specify and direct national R&D priorities is a key matter for NUMO.

3.8

A central aspect of NUMO’s development is to ensure that it is informed of and makes
best use of the intensive development work on GD that is taking place in othercountries. NUMO has been able to do this by involving scientists and programmemanagers from other national GD projects as advisers and in R&D work, as well as
taking an active part itself in international programmes. The review Panel believes that
this is an area where NUMO should continue to be active and maintain a high profile,
taking advantage of involvement in large scale demonstration and testing projects inthe advanced European programmes that expect to be implementing GD by 2025. In
so doing, it would be helpful if NUMO could identify topics where its approach may
differ from, or be in the lead of approaches used in other countries (e.g. few othercountries have to deal with tectonic activity of the same scale as does NUMO, which
has led them to the development of pioneering methodologies). To facilitate informationexchange and make co-operation more efficient, the Panel suggests that it would be
helpful if NUMO were to publish more of its documentation in English.

4 NUMO’s Safety Strategy
4.1

NUMO is following the internationally accepted approach to establishing the safe
disposal of radioactive wastes through a hierarchical approach to safety. The safetyconcept that underpins GD is essentially based on the use of a multi-barrier system,
where a combination of engineered and natural barriers provides isolation of thewastes from the surface environment and containment of the radionuclides associatedwith the wastes. A long-term safety case is developed for the concept or concepts
under consideration, to provide a key input to decision-making in the stepwise
implementation of the programme. The safety case comprises a number of elements:osafety functions of the various components of the multi-barrier system for a
specific safety concept and how they are met;osafety assessment, analysing the performance of the overall system, quantifying
radiological dose or risk resulting from disposal system evolution and providing
feedback on what is important and what not;4

omultiple lines of arguments; e.g. natural analogues;oquality of arguments, data and analyses; management of uncertainty; evaluationof confidence;

A different level of detail will be associated with each of these elements according to
the different stages of the implementation programme and the varying requirements ofdifferent audiences for the safety case.
The safety strategy brings all of this together by managing the supply and integrationof information from site characterisation, engineering design and research anddevelopment; iteration to identify further information needs; and matching repository
concept and design to the conditions at a potential site.
This overall approach to safety is considered in more detail in the remainder of Section
4.
4.2

The Safety Strategy developed by NUMO represents, in principle, a state of the art
approach that utilises concepts from other national programmes, has a firm basis in theinternationally accepted methodologies described at 4.1 (arising from the IAEA andNEA 2 ) and is adapted to the particular requirements of the evolving Japanese
regulatory system. Although the Panel has some specific issues to raise concerning
the use of terminology, we consequently consider the basic framework to be sound andready for application at this stage of the GD programme, although we consider that
benefits could be gained from trialling some aspects of the approach in the immediate
future (see 6.7).

4.3

It is clear that the search for increasingly higher levels of safety assurance is thedriving force in the step-wise approach chosen by NUMO. There will be a number ofcheckpoints at which the real progress in this direction will be assessed before moving
to the next stage. The whole repository development programme has been considered,up until final closure. The detailed roadmaps show that NUMO has a goodunderstanding of the activities needed in the future. We comment further on theroadmaps at 5.1.

4.4

Japanese policy is to “confirm” long-term safety. Whilst this may be a nuance oftranslation, the Panel feels that there is scope for misunderstanding about what‘confirmation’ might imply. The emphasis needs to be placed on choosing a good site,
within the constraints of the site selection process, and matching it with a good
repository design, for which there is a sound scientific and technical basis. At the earlystages of implementation in particular, the main objective for NUMO is to show that it
has the knowledge and capability to propose a disposal system that has the prospectof being safe, subject to gaining an adequate understanding of site conditions andbeing able to analyse the evolution of the system under those conditions. Thus, indiscussions with communities and other stakeholders, NUMO can make it clear that it
intends actively to create safety by selecting a good site and a design adapted to thewastes disposed of and the site selected.

4.5

The foundation of NUMO’s approach to safety is three ‘policies’ that are designed toreach the goal of ensuring safe disposal. For the Panel, these are clearly a componentof NUMO’s approach to producing, managing and presenting information in its safety
strategy. It would be useful for NUMO in communicating its safety strategy to describe
the process that led to it defining these policies, why they were chosen and how it will
ensure that the overall goal (safe disposal) is met.

4.6

In most national programmes (e.g. Belgium, Finland, France, Switzerland, UK) thesafety case and the supporting safety assessments are central to decision making fromthe outset of the programme, including the site selection process. Initially provisional

2

Geological Disposal of Radioactive Waste, Safety Requirements. Jointly Sponsored by the IAEA and the NEA,
IAEA: Safety Standards Series No. WS-R-4, International Atomic Energy Agency, Vienna.

Post-closure Safety Case for Geological Repositories: Nature and Purpose. NEA Report Number 3679. OECD/NEA
Nuclear Energy Agency, 2004, Paris, France.

5

cases/assessments are an input to all the important decisions and help to identify
unresolved, relevant issues. A regularly updated safety case will also be used for
guiding the R&D work. This central role of the safety case does not have great
prominence in the documentation provided to the Panel, nor do the ‘anchor points’ or‘guiding lights’ of safety functions. It appears that safety functions will only be defined
after some analysis of a disposal concept that has been tailored to site conditions. It
would inspire much greater confidence if the safety functions were to be defined initially,
since NUMO, R&D organisations and other stakeholders will then be able tounderstand what is considered to provide safety and what must therefore be tested.
4.7

Bringing all of this together in safety assessments appears clearly in the different stepsof the safety roadmap, but the outcomes of the iterative development of the safety caseand the completion of the safety assessments seem not to drive the decision making
and the approach chosen. This seems a critical matter to the Panel and we make aspecific suggestion on how NUMO might strengthen its capacity in this area at 6.7.

4.8

The Panel notes that safety assessment has two overall goals: to evaluate theexpected level of safety (including the meaning of remaining uncertainties) and toprovide feedback for system development (e.g., matching repository design to the site).
Safety assessment should thus be presented as a tool for integrating the informationthat has been acquired up to a given point from site investigations, engineering design
and R&D, and for analysing the consequences of the uncertainties associated with that
information in order to prioritise further information-gathering. Currently, theinterdependence of repository concepts, the safety concept and safety functions, does
not emerge with the necessary clarity. It may be useful for NUMO to explain the use ofsafety assessment within a strategy of “adaptive staging”, in which the importance of
feedback and guidance for site selection, guiding RD&D, etc is more clearly visible. A
planned, adaptive staging strategy also allows NUMO to make use of a flexible
approach to all aspects of its programme. Experience with other national programmes
is that the need for, and benefits of, flexibility need to be explained early on in a
programme, to avoid misunderstandings about ‘changes of direction’, which can beharmful to the GD programme.

4.9

In developing its strategy, NUMO is thinking far ahead. The timescales to the DIA
stage are already long and to the point of construction and operation are one, possibly
two, generations into the future. Consequently, we can expect that the details of thestrategy will change to accommodate developments in the siting programme. The
important thing for NUMO is to have the elements of a workable plan, and we believethat this is well demonstrated in the documentation provided. The critical part of theplan clearly concerns the next 5 to 10 years and we comment further on this at 5.1.

4.10 Some national programmes are required to use the BAT (best available technology)
approach to interfacing design with safety. The Panel suggests that this may not be themost appropriate conceptual basis for NUMO, as it is open to subjective interpretation,
can introduce adaptations with nugatory benefits for large resource commitments andmay thus constrain optimisation, unless implemented as ‘BATNEEC’ (BAT not entailingexcessive cost).
4.11 There are areas of work where we consider NUMO needs to be proactive in the shortterm (i.e. next five years) and also to take the leading role:•

The development and analysis of scenarios and the application of probabilistic
methodologies to assess the likelihood of lower probability scenarios. We
consider that NUMO could provide valuable information here to inform thedevelopment of appropriate regulatory standards by, for example, scoping therisks associated with low probability events.

•

Related to this, NUMO should extend its consideration of the very long-term(beyond 100,000 years) to answer questions about the ultimate ‘fate of therepository’. In some national programmes, eventual exposure of the repository
by uplift and erosion is having to be addressed, even though it is only apossibility in the very distant future (millions of years) and this has regulatory
implications.

6•

Scoping out the safety case implications of significant design alternatives for(a) different geological/geographical environments, (b) different approaches tomanaging the waste in terms of storage and retrieval, and (c) different
inventories and different scenarios of development of the Japanese nuclear
power programme.

5 NUMO’s Project Plan
5.1

The impressive series of roadmaps that contain NUMO’s Project Plan reveal the depthof thinking that NUMO has put into planning. They appear to contain all major aspects
that need to be considered. In the Panel’s view, the challenge to NUMO will be ininterfacing the requirements that the roadmaps place on the organisation with its actual
work programme. The project plan has addressed the many important steps in the total
programme, but many of these are far into the future. One area that could be moreclearly represented in NUMO’s plans is the immediate steps and activities that NUMO
will need to activate as soon as potential host communities emerge from the volunteer
process. It would be valuable for NUMO to be able to state exactly, step by step, how itwill initiate and carry out, for example, the first year of its programme as it enters theliterature review, as this will be where the strategy will be most obviously and publicly
tested.

5.2

Thus, an important impression of the Panel is that NUMO has identified andunderstands the issues to be addressed very well, has a structured project plan
represented by the detailed roadmaps, but will need to put much effort into mapping its
issue resolution activities (R&D and other work) onto those roadmaps. The
management framework within which to make the decisions on crucial points such assite selection and/or the exclusion of sites, defining the site characterisation
programme, selection of the disposal concept and optimisation of the design is not soclearly presented, and the involvement of stakeholders and research organisations inthese decisions is currently not clear.

5.3

The Panel suggests that NUMO takes care to differentiate between the selection of apotential host rock at a site and choosing a location for the repository within the hostrock. It would be helpful if NUMO were to explain the challenges that will be faced
when a volunteer area enters the process, in terms of the possible choices between
rock types.

5.4

The Panel felt that NUMO may be overemphasising the significance of the informationthat can be derived from monitoring in the R&D and safety strategy. While this is an
important topic to have a strategy on and to be able to discuss with the public, it should
not be allowed to become confused with other design and management issues that will
really affect safety and viability.

5.5

In this respect, NUMO’s documentation dwells rather more on far-field (natural barrier)retardation performance (i.e., on radionuclide mobility and transport) than on thecontainment provided by the engineered barriers and the Panel considers that thelatter should be given more prominence in the way that NUMO presents the GD
concept. At present, safety assessment is largely presented as a tool for conducting
radionuclide transport calculations. Particularly at the early stages of site selection, amuch more important role will be to present the developing understanding of thecontainment potential of all components of the multi-barrier system under the likely site
conditions and the extent to which this matches up to their defined safety functions.

5.6

Topics where NUMO might wish to consider placing increased programmatic emphasis
include the following:•

Deeper investigation of repository concepts that are alternatives to theemplacement methodologies used in H-12. The Panel considers that it would
be useful for NUMO to carry out simple, scoping evaluations of the benefits
and drawbacks of different designs in different situations and waste
management scenarios, so that it can gain a clear picture of whether (and in7

what circumstances) it would be beneficial to give serious consideration toother repository concepts;•

Clarifying how exactly it will link the functionality of Site Descriptive Models to
the rest of the programme. NUMO is unclear on what level of information it
expects that it will have collected by the end of each stage of the site selection
process, referring rather to types of investigation methods. Care needs to betaken about the assumptions on the level of detail of information that can beavailable at early stages as an input to repository design. The assumed
characteristics of each successive site descriptive model need to becommunicated more clearly to build confidence (or otherwise, to test) that the
information required will be available;•

Safety aspects of transporting waste to the repository site: even though this iscarried out as a routine operation worldwide and is subject to rigorous anduniversally accepted IAEA regulations, it is a topic that is always of interest andconcern to the public – both from the radiological and the environmental
perspectives (and the latter also affect other transport activities around therepository area);•

Being prepared to respond to questions about which rock properties areimportant in its safety case, how they contribute to safety and what type of
THMC conditions would be favourable for a host rock. Whilst there is anunderstandable reticence within an entirely volunteer process to be in any way
prescriptive, a qualitative or semi-quantitative discussion of how certain
properties contribute to safety would be valuable in answering the inevitablepublic question of ‘what are you looking for?’6 Suggestions for NUMO’s Forward Planning
6.1

In this Section, we make additional suggestions that may assist NUMO in presenting
and implementing its forward plan. We note that some of our suggestions go beyond
NUMO’s own immediate responsibilities in that other organisations would need toconsider them. We consider that it would be valuable to the Japanese GD programme
for NUMO to enter a dialogue with the relevant government and other agencies onsome of these matters.

6.2

If the volunteer siting process leads to a decisions for co-disposal of HLW and TRU
wastes then this will have significant effects on the nature and content of NUMO’stechnical work programme. At present, it is thus difficult for NUMO to focus the R&D
and site evaluation programme but the Panel suggests that NUMO needs to consider
both possibilities (separate or co-disposal) in all aspects of its planning and activities.
This will have important resource implications for NUMO.

6.3

A similar issue is the option/possibility of having to abandon a site during the siting
process. Experience from other national programmes is that technical surprises willalmost certainly arise in the siting process, which might require an adaptation of theconcept, and it cannot be a priori excluded that a site has to be abandoned. It will thus
be useful for NUMO to share with volunteer communities its thinking about thepossibility of surprises, the likelihood of adaptation and the consequent need forflexibility (especially in the early PI period). Taking this a step further, it would also be
useful for NUMO to explain to communities how it will choose between two clearlysuitable sites and the point in the programme up to which communities can withdraw
from the siting process.

6.4

It is widely recognised internationally that gaining public approval is essential for GD
projects. Although NUMO has an active outreach programme to the public, the Panelgained the impression that the public may not be sufficiently involved in an active andequal fashion – something that has been found essential in other national programmes.
Having a programme that is able to ‘listen and adapt’ seems to be a prerequisite tosuccess in most countries and simple explanation of a programme is not enough.

8

Consequently, the Panel suggests that it may also be useful for NUMO to interact withspecialists in communicating to and interacting with different audiences about scientificand risk issues. There are ethical and societal considerations in discussing hazards
and the provision of safety over very long time periods that require more than just anatural sciences input. The underlying necessity of having clear social and ethicalstandards and positions is recognised by NUMO but may be an area that could befurther developed with expert assistance and more prominently advanced incommunicating with potential host communities.
6.5

We believe that it would assist the overall Japanese nuclear power programme if thedifferent wastes destined for GD were placed into a broader national context of how thenuclear fuel cycle may develop. There are clearly many issues of optimising just thedisposal aspects that also affect optimisation of the fuel cycle, and vice versa. NUMO
could take a prominent role in explaining the alternatives pathways and options within
its overall management strategy and how these could beneficially affect national
decisions on nuclear power production. Examples of alternatives, some of which havealready been mentioned, include: length of storage time for HLW; co-disposal with TRU
and, possibly, other wastes; combining protracted, high-security storage undergroundwith eventual disposal; the possibility that some types of fuel will not be reprocessed infuture and may require direct disposal etc.

6.6

Several Japanese organisations are carrying out fundamental research into long-term
safety issues. Some of this research is currently outside the realm of NUMO, but theimplementation of the safety strategy described in the report requires that NUMO hasmeans to guide the ongoing and future research programmes in the direction that
corresponds to its information needs. For example, in Finland, Posiva (as the ‘enduser’) is responsible for the whole of the R&D programme that generates theinformation that it needs. The same situation exists in Sweden and also in Switzerland.
In the UK, the NDA has a published R&D strategy and commissions R&D to meetthese strategic requirements, for example, sponsoring R&D in universities andmaintaining close contacts with the national research councils. It is important for the
success of the Japanese GD programme as a whole that mechanisms are in place sothat NUMO, the end-user of this information, can take this guiding and commanding
role.

6.7

It is 12 years since H-12 and the exercise carried out recently for TRU did not involve
NUMO, which was not at that time responsible for TRU disposal. A major challenge for
NUMO will be to integrate the efforts of the different teams that will be involved insafety assessment, design and site evaluation, especially when much of the practicalwork will be carried out by the wide range of organisations mentioned above. It isevident to the Panel that a range of site and safety assessment techniques have beendeveloped in a non-centralised way and that making them interlock to make a fully
integrated safety assessment (for example) will be challenging. Because it will be sometime before site-specific information comes along so that NUMO can conduct a first,
fully focussed, safety assessment, there is a potential window of opportunity in which
this could be done. The Panel therefore suggest that NUMO might consider running amock assessment exercise, with its own staff acting as the project directors and theobjective of carrying out a comprehensive assessment at an example location, bringing
together its work on site descriptive models, repository concepts, scenario
development, tectonic hazard analysis and safety assessment methodologies. The end
result itself will be unimportant, quantitatively – the aim is rather to test themechanisms for managing interactions between groups and organisations and thesuccess of these interactions. This approach has proved invaluable as a team-building
and understanding-building tool in a number of organisations in other national
programmes (for example, the Site-94 project in Sweden). NUMO would need todecide whether it is practical to run such an exercise in parallel with initiating literature
surveys on any volunteer sites that may arise in the coming year or two.

6.8

The regulatory basis for GD in terms of specific dose and risk guidelines, and otherrequirements on NUMO as an implementer, is under development and, we understand,may take some years before it crystallises completely. Establishing standards needs tobe done within both a clear scientific framework and a context of identifying and9meeting societal expectations. It is clear that NUMO has carried out work on issues
that would be influential in establishing national standards and that NUMO
consequently should have a strong voice in such discussions. The Panel encourages
NUMO to set out its own ideas on appropriate approaches and to help foster open
discussions with other government agencies and with the public.
6.9

The Panel understands that retrievability is a requirement on the Japanese GD
programme. Provision of specific capabilities to facilitate retrieval could have impacts
on the long-term safety case and operational safety. As with other national
programmes, NUMO will have to ensure that any such provisions that it may berequired to make do not unduly affect the pre- or post-closure safety of the repository.

7 Concluding Remarks
7.1

NUMO’s primary intention in developing the ‘2010 Report’ has been to show that they
have the knowledge, tools and strategy to be ready to continue their carefully plannedsite selection process with literature surveys and preliminary site investigations, assoon as candidate sites become available.

7.2

The impressive series of roadmaps that contain NUMO’s Project Plan reveal the depthof thinking that NUMO has put into planning to meet this objective. They appear tocontain all major aspects that need to be considered. NUMO has identified andunderstands the issues to be addressed very well, has a structured project plan
represented by the detailed roadmaps, but will need to put much effort into mapping its
activities onto those roadmaps.

7.3

The Safety Strategy developed by NUMO represents, in principle, a state of the art
approach that utilises concepts from other national programmes, has a firm basis in theinternationally accepted methodologies and is adapted to the particular requirements ofthe evolving Japanese regulatory system.

7.4

The Panel considers that it would be useful for NUMO to carry out simple, scoping
evaluations of the benefits and drawbacks of different repository concepts and designs
in different situations and waste management/inventory scenarios, so that it can gain aclear picture of whether (and in what circumstances) it would be beneficial to give
serious consideration to other concepts.

7.5

In these early stages of implementation the Panel considers that the highest levelobjective for NUMO is to show that, for a potentially wide range of siting environments,
it has the knowledge and capability to propose a disposal system that has the prospectof being safe, subject to gaining an adequate understanding of site conditions andbeing able to analyse the evolution of the system under those conditions. NUMO also
needs to know when it has to exclude a site. In the Review Panel’s opinion, theinformation received from NUMO and the outcomes of the discussions held with them
fulfil this objective: it is clear that NUMO knows how to continue the geological disposal
programme and what the challenges are for the future. However, the Panel believes
that NUMO could be much clearer about the step-by-step activities included in these
immediate steps into the LS and PI stage in order to be absolutely convincing. The
Panel believes that this may simply be a matter of assembling and presenting therelevant material in a more prescriptive way.

8 The Review Panel
Neil Chapman (Chairman): is Professor of Environmental Geology in the University of
Sheffield, UK, in the Department of Engineering Materials (part time), Chairman of the ITC
School of Underground Waste Storage and Disposal (Switzerland) and an independent
consultant in radioactive waste management with more than 30 years experience as anadviser to national and international programmes. He is the author of eight books and over
150 papers on radioactive waste management and was awarded the 2010 James Watt Medalof the Institution of Civil Engineers for published work in this area.

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Joonhong Ahn: is Professor of Nuclear Engineering at the University of California, Berkeley,
USA, where he specialises in research into multi-barrier geological repository systems, withparticular emphasis on performance and safety assessment. He is a member of the Nuclear
and Radiation Studies Board, US National Academies.
Alan Hooper: is visiting Professor of Repository Science and Engineering at Imperial College,
London, UK and acting Chief Scientific Adviser to the Radioactive Waste Management
Directorate of the UK Nuclear Decommissioning Authority (NDA). He has more than 30 years
experience of managing the scientific and technical activities in support of nuclear
decommissioning and radioactive waste management programmes for the UK electricity
supply industry and national waste management organisation.
Juhani Vira: is Vice-President for Research at Posiva Oy, Finland and responsible for theoverall management of site characterisation and research into long-term safety of the planned
repository for spent fuel at Olkiluoto. He has been working in the area of nuclear fuel cycle
and waste management since 1975, first as a researcher, later as a research manager.
Currently he is actively involved in the licensing process of the planned repository.
Piet Zuidema: is the member of the Executive Team that manages Nagra, the Swiss national
radioactive waste implementing organisation, where he is responsible for the overall
coordination and management of the Science & Technology programme. He has more than
25 years of experience. He was in charge of several major repository projects within the
Swiss deep geological repository programme and is also responsible for Nagra’s RD+D
programme. He is also member of several international committees (e.g. NEA / OECD) andhas participated in several expert advisory groups in other waste management organisations
abroad.

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