NUMO-TR-09-01

The NUMO International Technical Advisory
Committee (ITAC):
Background, accomplishments and perspectives on
the role of technical support groups

July 2009
Nuclear Waste Management Organization of Japan (NUMO)

2009 年 7 月 初版発行
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Preface
This report presents an overview of the roles and activities of the International TechnicalAdvisory Committee (ITAC), which served NUMO through its formative years from 2001 to
2008. This group supported NUMO during the time when many of the basic, often innovative,
concepts that characterise the Japanese deep geological disposal programme were developed.
This overview thus provides a perspective on these activities that is not available in othermaterial published in English.
ITAC Phase 1 has now been brought to a close, having served the role for which it wasplanned. It is intended that this document will provide an integrated record of the work of thecommittee, helping NUMO (and maybe also other similar organisations) to assess the relative
merits of its structure, remit and modus operandi in order to aid in the planning of future
review and advisory groups.
The report has been compiled from the records of the 12 ITAC meetings by the ITAC
chairman and secretary, who have endeavoured to place the committee’s work in context andto provide the background needed to explain its accomplishments to international readers.

1Introduction ........................................................................................................................ 1
1.1
Establishment of ITAC ................................................................................................... 1
1.2
Organisation of work ..................................................................................................... 3
1.3
Overview of topics considered ....................................................................................... 3
1.4
Current status ................................................................................................................. 5
1.5
Objectives and structure of this report ........................................................................... 62
Supporting the call for volunteers ...................................................................................... 7
2.1
The NUMO technical and societal siting process (voluntary; three stage) ................... 7
2.2
The documents supporting the call for volunteers ....................................................... 10
3
Advice on NUMO's technical siting process ................................................................... 12
3.1
The Siting Factors report ............................................................................................. 12
3.2
Site selection and characterisation .............................................................................. 14
3.3
Impact of the siting process on repository concept development strategy ................... 15
4
Repository concept development ..................................................................................... 16
4.1
The Repository Concepts report................................................................................... 16
4.2
Operational safety, practicality and logistics .............................................................. 17
4.3
Safety case and advanced performance assessment (PA) for comparison of options . 18
4.4
Special design topics – monitoring, retrievability and closure .................................... 19
4.5
Technical implications of added TRU responsibilities ................................................ 20
5
Organisational development of NUMO ........................................................................... 22
5.1
Structure and staffing ................................................................................................... 22
5.2
Working Standards and communication with regulatory bodies ................................. 22
5.3
QA / QMS ..................................................................................................................... 23
5.4
RMS / NSA .................................................................................................................... 24
5.5
Communication and confidence-building .................................................................... 24
5.6
Organisational implications of expanded responsibility for TRU ............................... 25
6Conclusions ...................................................................................................................... 26
6.1
Summary of the mission of ITAC Phase 1 .................................................................... 26
6.2
Current status of NUMO .............................................................................................. 26
6.3
Future challenges for NUMO ...................................................................................... 27
6.3.1
Programmatic challenges facing NUMO................................................................. 27
6.3.2
Technical challenges facing NUMO ........................................................................ 28
6.3.3
Why a pause and a re-structuring? .......................................................................... 28
6.4
How might the value of future advisory or review committees be enhanced? ............. 29
6.4.1
Factors influencing the choice of structures ............................................................ 29
6.4.2
Future NUMO external expert groups ..................................................................... 30
6.4.3
ITAC views on future expert groups ......................................................................... 31
7
Acknowledgements .......................................................................................................... 34
8
References ........................................................................................................................ 34ii

1 Introduction
1.1

Establishment of ITAC

In 2000, Japan was relatively late amongst the leading nuclear power nations in establishingan organisation devoted specifically to managing the country's nuclear wastes intended fordeep geological disposal. Many nations, including Belgium, Canada, Finland, France,
Germany, Sweden, Switzerland, the UK and the USA, already had (or once had) nationalorganisations charged with developing disposal solutions for such waste types. However, theJapanese Government and the nuclear utilities had engaged in extensive preparatory work,
focused primarily on generic R&D to establish fundamental generic feasibility (run mainly by
PNC/JNC), before establishing the Nuclear Waste Management Organization of Japan(NUMO) as the body responsible for implementing a repository for geological disposal of
HLW (further background on http://www.numo.or.jp/en/index.html). A precursor
organisation, SHP, operated for several years, gathering information and making contacts tonational waste management agencies around the world. In addition, one of the utilities
provided support and commissioned a series of position papers that then led to a special
seminar and ultimately a reference book (Chapman and McCombie, 2003). Such preparatory
discussions also addressed the topics of the form, structure, programme and advisory bodies
that could be best suited to a new disposal organisation.
Shortly after its establishment, NUMO engaged in bilateral discussions with the Swiss waste
management organisation, Nagra, on the topic of advisory bodies and this led to a “dry run”
with a technical group, including four individuals who later became members of theInternational Technical Advisory Committee (ITAC) that NUMO decided to establish in 2001.
The initial key objective was to ensure that NUMO could have access to the details of what
had been successful – and, very importantly, what had not been successful – in major foreign
programmes. The separation of roles into (a) advice on future plans and (b) review andtechnical support was discussed, but NUMO decided that, initially at least, advisory andreview functions could be covered by a single group.
Accordingly, invitations were extended to individuals who had in-depth knowledge of othernational programmes and could therefore help NUMO to benefit from lessons learned in these.
In the original Terms of Reference of ITAC, it was stated that, to perform their role optimally,
ITAC members should meet as many as possible of the following requirements:
•
•

•
•
•

wide and long experience in one or more foreign waste disposal programmes
scientific and technical expertise in some of the following key areas:o overall waste disposal strategies and conceptso siting procedures, engineered barriers, performance assessment andconfidence-buildingo procedures for independent international review and programme support
familiarity with the structure and the content of the Japanese HLW programme
good network of external connections in the waste disposal field
an internationally established personal reputation to help enhance the credibility of
NUMO.

1

In this way, ITAC membership gradually expanded to include individuals with intimate
knowledge of key national programmes, as illustrated below.
CanadaFinlandFranceGermany
SwedenSwitzerland
UK
USA (WIPP)
USA (Yucca Mountain Project).
International

Keith Nuttall
Juhani Vira
Bernard Faucher
Klaus Kühn
Johan Andersson
Ian McKinley (Secretary)
Neil Chapman
Erik Webb
Mick Apted
Charles McCombie (Chairman)

However, the selection also covered a wider range of programmes in which these individuals
had been actively involved, including:• Further national programmes in Taiwan, Korea, China and South Africa• International studies of the IAEA, NEA, EC, Pangea Project and Arius
The mechanisms employed to efficiently transfer experience in a variety of key areas aredescribed below. A particularly important selection criterion was that ITAC members should
ideally have prior knowledge of, and experience with, Japanese waste management work.
This helped to lower hurdles that could have resulted from lack of familiarity within ITAC
regarding the technical progress and cultural environment in relevant Japanese R&D areas.
However, the role of ITAC has not been confined to the transfer of past know-how andexperience. The Committee’s functions have evolved over seven years in a variety of advisory
and review modes, designed to also ensure that state-of-the-art work is performed by NUMO
and to provide forward-looking perspectives. In summary, the roles of ITAC have been:
•
•
•
•
•

Transfer of past experience from established national waste management programmes,
as described above.
Providing direct input to technical documentation, in particular to the NUMO
documents accompanying and supporting the solicitation process for volunteer siting
communities.
Review of technical strategy, work programme and individual projects.
Advising on setting priorities and introducing new activities.
Providing direct support to NUMO technical staff in selected areas.

This last bullet point is somewhat unusual for formal advisory committees, which do notnormally become directly involved in the work of the programme on which they advise. It
was nevertheless judged to be an effective approach, given that various ITAC members arerecognised experts in relevant work areas and are well suited to providing such hands-on
support. Naturally, when ITAC was engaged in review of work packages carried out withdirect involvement of individual ITAC members, these members were then considered as partof the NUMO team and assisted in presenting projects rather than commenting on them.
A final key point concerning the basic structure of ITAC is that it was not designed to be thesole body providing advisory input to NUMO. At the same time as ITAC was established,
NUMO set up a Domestic Technical Advisory Committee (DTAC) in order to allow in-depth2interactions with the Japanese scientific and technical communities. DTAC members also
sometimes acted in direct support roles as well as top-level reviewers and advisors (Kitayama
et al., 2005a).

1.2

Organisation of work

The frequency and the content of ITAC meetings were adapted over the years to reflect thechanging needs of NUMO. Each of the twelve meetings that took place lasted three days. The
first day was generally devoted to NUMO providing an overview of its programme status and– importantly – to NUMO providing responses to the ITAC recommendations from theprevious meeting. Much of the remainder of days one and two was devoted to individual
NUMO Project Leaders presenting the status of their projects, responding to comments fromITAC and discussing any recommendations made. While the primary focus of NUMO
presentations was on technical topics, presentations were also made to ITAC by NUMO’s
public relations group, in order that ITAC might also advise on issues and factors related to
NUMO’s approach to seeking volunteer communities as possible candidate repository sites.
With time, an additional agenda item was introduced, in which ITAC members summarised
national positions on selected key topical issues. The areas addressed are listed in thefollowing section. On the third day, a closed session of ITAC was held. This lasted several
hours, during which a formal presentation of principal conclusions and recommendations was
prepared for delivery to NUMO senior management and technical staff. This presentation,
which concluded each meeting, together with any clarifying questions from NUMO, were
documented subsequently to provide a formal record of the meeting, which was thenpublished on the NUMO website.
As mentioned above, direct collaboration between individual ITAC members and NUMO
project staff was also part of the functioning of ITAC. This occurred in formal sub-groups or
projects or by NUMO directly allocating technical tasks to individual members. Technicalareas that have benefitted from such "hands-on" involvement include the tectonic studies
performed in the ITM project, work on repository design concepts, development of sitecharacterisation planning manuals, studies on requirements management systems (RMS) andon implementing Working Standards, use of multi-attribute analysis, etc. As several ITAC
members were members or contractors of sister organisations that subsequently establishedbilateral collaboration agreements with NUMO, this provided yet another mode forinteraction.
Further ITAC activities have involved interactions with DTAC. There have been only two
formal combined meetings, but joint appearances at public meetings and in workshops also
took place. The final ITAC meeting also included a trip to Rokkasho to view the relevant
back-end activities at this site. Although requiring considerable effort from the NUMO side,
this was very useful for ITAC – particularly in relation to NUMO’s enhanced responsibility
for TRU, as discussed in more detail in section 4.5.

1.3

Overview of topics considered

The topics covered during the 12 ITAC meetings have been strongly determined by the
evolving needs of NUMO. At the outset, the major effort was on advising on input to thesolicitation documentation prepared for NUMO's voluntary siting strategy and on reviewing
the various drafts produced. This was an extremely important task, since these documents3were the first scientific/technical publications of the new waste management organisation andhence vital for helping to establish NUMO's credibility with the public and also with theinternational waste management community. The ITAC input was not only on the content, butalso on the presentation of the material and its tailoring for particular audiences. Behind thediscussion on the key documents lay intensive technical exchanges on the siting factors to be
used and on the range of repository design concepts to be examined.
Further in-depth technical exchanges have taken place on the topics of regulatory frameworks,
site characterisation, performance assessment and operational logistics. NUMO benefited not
only by receiving direct access to current information from various national and international
programmes, but also by hearing the open discussions and comparisons made by ITAC
members when contrasting the varying approaches adopted in different countries on similar
topics.
In addition to addressing such purely technical issues, ITAC also reviewed and advised on thevarious project management and decision-making structures and processes being developed in
NUMO. The principal initiatives here involved development of the NUMO Structured
Approach (NSA), which was designed to provide an overall framework for the flexible
tailoring of its activities required by the volunteering approach to siting. Advice was given on
the overarching structure of the NSA and also, at a more detailed level, on components suchas the Requirements Management System (RMS), Working Standards and a Quality
Management Programme. Finally, although not part of its principal Terms of Reference,
ITAC has been informed throughout by NUMO on its public communication programmes
and, in fact, communication and public confidence were a focus at one meeting. The figure
below gives a concise overview of the timing of the ITAC meetings and of the focus in eachperiod of its work. The different levels (1 to 3) of the solicitation documentation are explainedlater in section 2.2.

Figure 1-1:

Overview of the timing of the ITAC meetings, main documents and topics of
discussion.

4

As explained above, a common feature at ITAC meetings has also been a series of concise
presentations by members summarising national positions on key topical disposal issues. A
list of the titles of these special agenda items illustrates the range of subjects covered:
•
•
•
•
•
•
•
•

1.4

International HLW Programme Reviews: status with respect to siting / siting factors;
safety case; repository concepts and practicality of implementation (ITAC 3)
Site Characterisation Programmes (ITAC 4)
Quality Assurance in National Programmes (ITAC 5)
Timescales for Compliance (ITAC 8)
Public Communication (ITAC 9)
TRU Disposal (ITAC 10)
Repository Closure and Monitoring (ITAC 11)
Use of Technical Review and Advisory Groups (ITAC 12)

Current status

Initially, the most important and urgent task was to ensure that the documentation for thesolicitation process was sufficiently complete and of high quality. These were essential prerequisites to helping establish the technical credibility of NUMO as a repository
implementing organisation. For this reason, initial ITAC meetings were relatively frequentand concentrated on the solicitation documentation. Subsequently, NUMO's main task was toprepare for the siting work that will follow the emergence of volunteer communities and toinitiate all of the activities that are necessary in an established, major repository organisation.
The current situation is that most of the essential programme elements have been put in place
and that, in some technical areas, NUMO is now at the forefront along with other leading
programmes. After several years of development, NUMO has now established its technicalcredibility in Japan (especially with academics and professional organisations). It has also
become a well regarded organisation within the international waste management community.
Its scientific basis equals that of other national programmes in virtually all areas, withsuperior expertise in some selected key areas, such as understanding of the impacts oftectonics and volcanism. It has recognised the crucial importance of quality management andcontinues to develop its structured approaches to implementation, supported by appropriate
management tools. Unfortunately, volunteers have not yet come forward and this limits thetechnical activities that NUMO can undertake.
A further important boundary condition is a recommendation from a Government subcommittee that all main organisations in the radwaste field (implementers, regulators andsupporting R&D institutions) should have independent advisory and review groups. As noted
above, this was initially considered by NUMO; however, for the first phase of work describedin this document, a more efficient structure was preferred, with ITAC members being
involved in advisory work, review activities and even in directly assisting NUMO staff in
specific project areas. The appropriate delineation of these roles in future advisory bodies that
NUMO may appoint is discussed in chapter 6 of this report.
When site-specific investigations are started, NUMO's primary technical need will no longer
be the transfer of experience from other national programmes. More emphasis will be placedon mastering current and future scientific and technical approaches to site characterisation,site selection, engineered barrier development, repository design, repository operational andlong-term safety assessment, etc. For this future work, a new ITAC phase will be introduced,
5

with participants bringing expertise in key disciplines rather than experience from national
programmes. Accordingly, it has been decided to conclude the activities of the current ITAC
and reconstitute future technical advisory / review committees when the next phase of theJapanese national disposal programme has been better defined.

1.5

Objectives and structure of this report

The present ITAC has provided a valuable service during the initial years of a major new
national programme. This report documents how the Committee operated and what has beenachieved. The target audiences include:••••

The Japanese Government and NUMO senior officials, who should be able to judge towhat extent the resource-intensive advisory activities of ITAC have contributed to thenational disposal programme.
The Japanese scientific and technical community, which should be aware of thebreadth and depth of NUMO’s work to respond to the technical challenges associatedwith a deep geological disposal project under the boundary conditions in Japan.
NUMO staff, who can review the ITAC Phase 1 contributions in order to optimise thestructures and working procedures chosen for future advisory groups.
The international waste management community – and especially the increasing
numbers of new nuclear nations – to communicate lessons learned and help partnerorganisations judge the pros and cons of establishing such groups.

One important objective at the conclusion of this report is to provide a list of suggestions thatmight be of value to NUMO when managing its future project work and, in particular, when
re-introducing technical advisory or review bodies for its repository implementation
programme.
To enhance the utility of the report, the many topics addressed by ITAC during its 12
meetings are addressed not in a chronological fashion but rather grouped by theme.

62 Supporting the call for volunteers
2.1 The NUMO technical and societal siting process(voluntary; three stage)
The approach to be followed in Japan was laid down in the Law of 2000 (METI, 2000), whichstates that the Ministry of Economy, Trade and Industry (METI) is responsible forformulating and announcing a basic policy for the final disposal of specified radioactive waste
which should include:
•
•
•
•
•
•

A fundamental endorsement of final (geological) disposal of specified radioactive
waste
Factors concerning the selection of preliminary investigation areas, detailed
investigation areas and sites for repository construction
Policy measures designed to promote the understanding of interested local citizens
with respect to the selection of areas/sites
Issues concerning the implementation of final disposal of specified radioactive waste
Issues concerning the development of technologies for final disposal of specified
radioactive waste
Measures designed to promote the understanding of the general public regarding final
disposal of specified radioactive waste

NUMO was charged with tasks starting from selection of the preliminary investigation areas(PIAs), detailed investigation areas (DIAs) and sites for repository construction, through tooperation and closure of disposal facilities for the initially “specified” high-level waste(HLW) from reprocessing of spent fuel. The Law also described PIAs and DIAs as follows:••“Preliminary investigation area” means any area where, based on literature surveys,
data and other evidence, significant tectonic activity resulting in earthquakes,
volcanic activity, uplift, erosion or other natural disruptive phenomena is unlikely tooccur now and in the future.
"Detailed investigation area” means any preliminary survey area where site
investigations have indicated that the potential host geological formation is stable atpresent and is likely to remain so in the future and that tunnels and other undergroundstructures can be excavated in the formation without difficulty.

Based on this background, a stepwise siting strategy was developed for Japan, as illustrated in
the NUMO schematic below.

7Figure 2-1:

The three stages of the site selection process.

The Government policy did not specify what process NUMO should use in order to identify
and then narrow down the potential siting regions. Comparisons with other national
programmes and their progress over the two last decades of the 20th century indicated that
selection methods had been evolving. In the early days of repository programmes, "top down"
decisions were taken by experts (often behind closed doors) and then a siting decisionannounced to the public with some justification provided. This "Decide, Announce, Defend"
approach had, however, run into problems in various countries and it was increasingly
acknowledged that consent of the local siting community was a great advantage – or even anecessity. Accordingly, NUMO decided that the societal aspects were so important that apurely volunteering approach would be adopted.
ITAC members strongly supported the concept of such a volunteering approach. Even though
it was novel, this was considered to be forward-looking and represented a sensible
extrapolation from international trends towards increased involvement of host communities. It
was also considered to be well anchored within NUMO’s policy of openness and transparency
in the siting process. Nevertheless, ITAC recognised that this approach would lead to many
challenges for NUMO – both technical and institutional – and these have been a focus formuch of ITAC's subsequent deliberations.
Despite the problems that have been experienced in soliciting volunteer communities over thelast five years, it can be seen that NUMO’s choice of a volunteering approach was apioneering decision that has influenced later siting work in other major nuclear programmes,
such as those in Canada (NWMO, 2008) and the UK (NDA, 2008a). These programmes may,in fact, have learned also from some of the difficulties that NUMO has faced in the Japanesesiting effort. In both the UK and Canada, considerably more time was invested in seeking
input from all parties including the public and building public consensus on the way forward
before actually issuing a call for volunteers. Also, in both cases the commitment required of avolunteer community was reduced below that required in Japan and direct government
support for the siting agency was more apparent than in Japan.
8

A commonality among all three national programmes was that their volunteering siting
approaches were each launched by a newly established organisation. NUMO realised that it isessential in such an approach that communities trust that the waste management organisation
will accept only volunteer communities that can be shown to fulfil the geologicalrequirements for safe repository siting. Since NUMO was a new organisation, a primary goal
then became the building of public trust in the technical competence, transparency and ethicalprinciples of NUMO. A key role of ITAC in its initial years of operation was to advise
NUMO on how this challenging task could be best addressed. The necessary elements were
judged to be:• a structured and clearly documented site selection process• a competent, well structured staff team within NUMO
• a comprehensive waste management programme for HLW• transparent documentation, making clear to the public that all of the above aspects areunder control.
ITAC also emphasised that the quality of the technical support documentation had to be very
high to give the necessary credibility to the disposal organisation, if the public were to be
asked to accept that an objective, scientific evaluation would guarantee that only geologicallysuitable sites would enter into the selection process. The concept of publishing "exclusion
factors" that would allow interested stakeholders to judge whether volunteer sites werepotentially suitable or not and also "favourable factors" that would identify features of sites
used to assess degree of suitability as a basis for site comparison was supported. The
development of a range of repository design concepts was recognised to be a naturalconsequence of NUMO's willingness to look objectively at any of the wide variety ofpotentially suitable siting environments that could conceivably arise from the volunteering
process. These important technical aspects are considered further in later sections.
In addition to such technical points, ITAC members also raised important institutional issues
that could affect the siting process. Clear and active Government support should be offeredthroughout. This is needed to facilitate the informal contacts with community officials, which
are often a necessary first step towards formal negotiations and which can help to surmountthe threshold barrier to the voluntary siting process. Sensitive issues such as the right ofwithdrawal from negotiations should be addressed early in the process, as should scenarios inwhich volunteers do not emerge or else an impracticably high number of communities registerinterest. Another critical issue was the matter of compensation – with the risk that this can beconsidered as "buying off" a community to accept a hazardous project. The entire aspect ofcompensation and its presentation was the focus of an informal review of national procedures,
which showed major differences between countries and illustrated how strongly this topic is
associated to local culture. Nevertheless, it is clearly an important issue which can encourage
volunteers, but has to be communicated by NUMO and governmental authorities with greatcare and in a manner appropriate within the Japanese national context.
A particular topic which was discussed on several occasions is the sensitive issue of what to
do if no volunteers come forward. ITAC considered it prudent to plan for such an eventuality
and examine how various options could facilitate soliciting of volunteers. Because of
NUMO’s particular boundary constraints, no specific actions were recommended, but clearly
this is a topic that might need to be revisited in the future.

92.2 The documents supporting the call for volunteers
The crucial documentation produced in support of the volunteering process was structured
into a comprehensive "Information Package" to be made available to all municipalities inJapan (English translations available on the NUMO website – www.numo.or.jp). The
structure of this Package, together with other supporting documents, is illustrated below.

Figure 2-2:

Structure of the Information Package and key supporting documents.

ITAC provided diverse recommendations that were largely taken on board by NUMO. These
included detailed review and advice on the format and content for all of the original level 1
and 2 documentation distributed to communities in the solicitation process. In particular, theconcept of the concise overarching document that was attached to the invitation of the NUMO
President was proposed by ITAC. Direct assistance was also given with English translationsof these reports.
The level 2 Repository Concepts and Siting Factors reports in the solicitation documentation
contained sufficient technical information to ensure that communities could have a realistic
picture of the impacts that volunteering as a PIA, or eventually hosting a repository, would
have on their locality. Some of the relevant issues discussed by ITAC were:••••

Practical details of the volunteering process, including clear specification of the degreeof commitment of volunteers at various stages of the project: this is still an open
question.
Involvement of the Government in the process: this was initially very limited, but has
become more active recently.
Ability of local communities to independently assess technical siting factors and the
support that could be provided to help them in this process.
Representation of repository concepts at a simple level: providing focus while
preserving flexibility to respond to both uncertain technical boundary conditions andsocio-economic constraints or requirements.

For the scientific and technical community, however, greater depth was required in the
NUMO documentation. Thus, ITAC strongly supported the concept of producing the twofurther level 3 reports on repository concepts and siting factors. In practice, individual ITAC
members worked directly with NUMO staff to produce the important English language10

versions of these documents, which served as an early demonstration to the national andinternational community of the quality of NUMO's scientific approach, as considered further
in the following sections.

113 Advice on NUMO's technical siting process
For the siting work, ITAC input included intensive discussion of the overall process and of
the siting factors (SF), including the important issue of the quantitative limits to be applied
therein. The classification of the SF into groups reflects Japanese law. However, instead ofnumbering these, ITAC worked with NUMO to develop more useful nomenclature andclassification. One category is defined as Evaluation Factors for Qualification (EFQ), which
are sub-divided into Nationwide Evaluation Factors (NEF) and Site-specific Evaluation
Factors (SSEF); these all relate to the basic acceptability of a site. A second major category,labelled as Favourable Factors (FF), will be used when sites are compared and ranked.

3.1 The Siting Factors report
As one of the first technical reports produced by NUMO and the first open discussion of thetechnical aspects of site selection, this document had very high importance for both the HLW
programme and establishing NUMO’s credibility as an organisation. ITAC strongly supported
NUMO’s decision to publish an English language version of this report and to produce this inparallel with the Japanese version. As with the Repository Concepts report discussed below, it
was emphasised that the English version was not a simple translation of the Japanese report,
but rather a modified version that took into account the different boundary conditions andbackground knowledge of national and international audiences. ITAC was involved in several
iterations of developing the contents list, draft text and illustrations for this report – much ofwhich was also reflected in the Japanese version.
ITAC emphasised from the start the challenges involved in the production of this report. The
volunteering approach would present difficulties in any country, but particularly so in a land
like Japan, with complicated geology in an active and complex tectonic setting. Particularly
for an international audience, therefore, the English version of the Siting Factors report(NUMO, 2004a) thus included extensive background on the geology of Japan, to put thefindings of the earlier H12 feasibility study (JNC, 2000) into perspective and support thedevelopment of the key “EFQ - NEF”. These are effectively exclusion criteria to ensure thatany sites that are unsuitable due to lack of required geological stability or the presence of
natural resources are not taken further in the siting process. Such assurance that unsuitablesites will not be considered is clearly critical to the credibility of the volunteering process and
ITAC invested considerable effort to support clear and defensible specification of theseparameters.
ITAC considered that the main EFQ were technically defensible and well described. The only
minor reservation – also found in other national programmes – involved definition of natural
resources, where conflicts could limit site acceptance. After much discussion, ITAC
considered the NUMO definition, which focused on currently utilised resources, to be apragmatic solution, but noted that input from the Government / regulators was needed in orderto ensure that the treatment of potential resources that were not presently utilised – inparticular, aquifers and geothermal resources – is clearly defined.
ITAC noted that the definition of the SSEF and FF is less politically sensitive, but more
technically challenging. This is due not only to the difficulties of assessing potentially12complex volunteer sites, but also to the decision to allow flexible tailoring of repository
designs to specific site characteristics, which introduces unusually strong coupling between
the site selection and repository concept development components of the programme. ITAC
recognised that this was very sensible given the boundary conditions of the Japanese HLW
programme, but noted that there was little international experience with such a process.
A further important ITAC discussion concerned the practical difficulties of carrying out site
investigations that conformed to the legal requirements on what activities are allowed in PIAs,
whilst at the same time allowing collection of crucial scientific data that must be gatheredoutside the PIA itself. The figure below, developed during ITAC brainstorming with the
NUMO siting team, shows how the requirement for Supplementary Investigation Areas(SIAs), which contain geological features that could influence the repository behaviour, could
be communicated.

Figure 3-1:

Schematic figure showing how the legal Evaluation Factors for Qualification
affect the identification of the location and geometry of a Preliminary
Investigation Area. (NUMO, 2004a)

Production of the Siting Factors report (NUMO, 2004a) was a focus for early ITAC efforts
and N. Chapman provided direct assistance in producing the first draft and incorporating
ITAC review comments into the final version. During the production of the report, several
important issues emerged from the summary of the geological setting of Japan in relationshipto arguments about geological stability. There were clearly some differences between ITAC
and DTAC with regard to the timescale of predictability of geological evolution of theJapanese archipelago – even after a joint meeting. This aspect of predictability is critical to
the treatment in safety assessments of future development of active faults or volcanoes or the
reliability of long-term uplift / erosion data.
Based on such considerations, both the Siting Factors and Repository Concepts reports
include a common introduction which emphasises the key timescale of concern for assessing
safety of HLW disposal. Although this is not reflected as yet in regulatory guidelines, there
are clearly arguments that the timescale for assurance of natural barrier performance should
be in the order of 10,000 years. After this time, the toxicity of HLW has decayed to a level
similar to that of the original naturally occurring uranium ore from which the reactor fuel was
fabricated. Certainly, for such a timescale, there is consensus between DTAC and ITAC that13

local tectonic evolution can be predicted based on extrapolation of the record of pastdevelopments.
Even though the toxicity is much less after 100,000 years, the hazard from a repository could
still be significant for extreme scenarios (e.g. sustained uplift and erosion). Further
clarification of the understanding of tectonic evolution was thus identified as a key area for
R&D – which resulted in the extensive ITM project, discussed further below.

3.2 Site selection and characterisation
Following publication of the Siting Factors report, ITAC discussions focused more onpractical aspects of site characterisation and the selection process. This was initiated by areview during ITAC-4 of the international state-of-the-art in siting, which illustrated thesignificant differences (and some similarities) between different national programmes. The
review highlighted, in particular, the contrast between the earlier technologically driven
programmes and more recent projects which place greater emphasis on public acceptance.
This was followed by an ITAC / NUMO brainstorming session to examine the consequencesof various possible volunteer scenarios – ranging from no volunteers to large numbers ofvolunteers that would stretch NUMO’s technical capacity at even the literature survey phase.
For such extreme options – and also the case of a single volunteer – it was clear to all
involved that technical aspects have to be set in the context of socio-political boundary
conditions defined by the various levels of Japanese Government and any volunteer
communities. Even in the favourable case of a “few” volunteers, NUMO’s planning for fieldwork and strategy for site selection would be considerably influenced by the extent ofvariations between sites.
Such strategic considerations were complemented by more technical evaluation of NUMO’splans for the initial literature survey and the process of selecting PIAs. ITAC recognised that
NUMO was planning such work well and making use of modern GIS technology – having
reservations only about NUMO’s ability to recruit and retain the key staff required tointegrate the diverse data that would be produced in the very short time allowed. This was arecurring theme, which is covered further in chapter 5.
Although the H12 report provides a good basis for synthesis of literature information, there islittle experience in Japan in planning and implementing a characterisation programme for the
deep geological environment. Thus, ITAC strongly supported NUMO initiatives to “mine”
international experience in the form of a “roadmap” that illustrated how specific technology
could be tailored to different sites. For such tailoring, a particular challenge for NUMO was
the wide spectrum of sites that could pass the exclusion filter of the EFQs and the range ofrepository designs that might then need to be considered – each with its own special
characterisation requirements. Here, it was recognised that NUMO’s “structured approach”(NSA: NUMO, 2007) and requirements management system (RMS) seemed to be appropriate
ways to respond to and manage these novel boundary conditions (discussed further in the next
section).
NUMO’s evolving plans for the PIA characterisation and the associated development of clear
goals that would form the basis of DIA selection were regularly reviewed by ITAC. In the14absence of volunteers, the NUMO siting team initiated a number of useful projects, inparticular:•••

In a project carried out for NUMO by the ITC, Site Characterisation Planning Manuals
were produced (with direct involvement of ITAC members Neil Chapman and Johan
Andersson).
Testing general manuals for site characterisation, developed based on Japanese andinternational experience, in “dry run” tests at geotechnical research sites.
The “ITM” project to expand understanding and gain consensus in the critical area of
tectonic stability.

These initiatives offered not only increases in the databases in important technical areas, butalso opportunities for key NUMO staff and contractors to gain practical “hands-on” field
experience and build up contact networks with some of the top Japanese and international
experts in critical topics. In addition to ITAC review of planning and progress, individual
ITAC members (N. Chapman and M. Apted) provided direct support for the ITM project,which played a particularly valuable role in establishing NUMO’s credibility in the tectonic
arena via high profile publications (Apted et al., 2004; Chapman et al., 2007; Goto et al.,2008; Tsuchi et al., 2008a; 2008b) and will result in a textbook that will effectively define thestate-of-the-art in this area (Connor et al., 2009).

3.3 Impact of the siting process on repository concept
development strategy
As noted above, at an early stage NUMO acknowledged the need to have a flexible range ofrepository concepts in order to make optimum use of any given site. This increases thetechnical complexity of deriving a site characterisation programme tailored to specificlocations and is the driving force behind the NSA, as discussed below. At early stages of thesiting work, however, ITAC agreed that it was sensible for focus to be placed on the “H12”reference designs (JNC, 2000). These have been shown to be particularly robust with respect
to post-closure safety over a wide range of credible site characteristics. It was emphasised,however, that implementation of such basic, generic H12 designs may be problematic under
expected geological conditions in Japan and, hence, factors that influence the safety andpracticality of repository construction and operation were particular focuses for the early sitecharacterisation phase.
In terms of direct feedback to modification of repository concepts to fit particular sites,
general examination of the distribution of sizes of individual Japanese municipalities, withconsideration of the requirement that potential siting areas should not contain active faults, led
to identification of the size of the repository footprint as a special concern for the reference
inventory of 40,000 waste packages. ITAC considered it prudent to investigate design variants
with smaller footprints, but also recommended consideration of a more flexible treatment of
inventories: considering whether smaller repositories would still be commercially practicaland the possibility of emplacing larger quantities of waste at a suitable site. For either case,clear communication to all stakeholders well in advance of a decision would be necessary.

15

4 Repository concept development
In the repository concept work, a key point was the recommendation to start with a range ofdesigns going beyond that proposed in the earlier H12 studies. In particular, ITAC continuallystressed that practical engineering aspects and also operational safety considerations would
play important roles in the final selection. A further important point was the emphasis on theneed for flexibility to tailor a repository concept to a volunteer site.

4.1 The Repository Concepts report
Like the Siting Factors report, the “Repository Concepts Catalogue” (NUMO, 2004b) was
seminal. It provided a novel approach towards documenting repository designs and forged apragmatic link between the generic preparatory work carried out by JAEA and the range ofdesign options that NUMO would need to consider for implementation at particular sites.
ITAC reviewed the development of the general concept and the contents of the catalogue insome depth – strongly supporting both the fundamental philosophy and the decision todevelop designs based on the well established H12 barrier components. Indeed, subsequently,
this step has been validated by the way in which it has influenced concept development inother national programmes (e.g. Defra, 2008, NDA, 2008b). ITAC did, however, emphasise
that, for particular sites or later as NUMO moves to actual implementation of a repository,
design concepts outside the H12 envelope might usefully be considered.
The English language report was produced with direct support from I. McKinley and involved
several iterations of intensive review by ITAC. In particular, transparent documentation of thedesign philosophy and design factors was considered to be an excellent way of improving
understanding by stakeholders – and it was emphasised that this is an integral part of NUMO's
policy of openness and transparency. Although flexible tailoring of repository designs is
undoubtedly a sensible approach under Japanese boundary conditions, it contrasts with theemphasis in many national disposal programmes on defining reference concepts. This latterapproach can certainly have particular advantages in terms of allowing R&D efforts to betightly focused and a well specified design concept is eventually necessary for performing
credible safety assessments to support licensing; however, there are also disadvantages inestablishing reference designs too early in a programme. These include loss of an“optimisation” mentality and waste of effort on concepts that are not appropriate under theboundary conditions of an operational repository – effects that can be seen from international
experience.
An important issue that couples the repository concept to the early stages of siting involves
constraints on site acceptability set by the practicality of construction of a cost-effective
facility, as indicated in the figure below. As emphasised by ITAC, although the EFQ“exclusion criteria” are well specified, the absolute limits on “practicality” are, to some extent,
set by the capabilities of current technology. It cannot be precluded that major advances infuture mining or materials technology could cause re-appraisal of such limits. For this reason,
it may be prudent to categorise sites that are not taken further on the basis of practicality as“reserves” rather than “rejects”. Nevertheless, to ensure NUMO’s credibility, it is also
important that the message is strongly presented that sites which are fundamentally unsuitable
for safety or operational feasibility reasons (see next section) will be excluded from16

consideration. Given this dichotomy, ITAC accepted the presentation of such issues in the
Repository Concepts report, but recommended that the entire process of site comparison be
carefully studied. This was implemented by NUMO in the form of a series of “dry run”
exercises for model sites that were representative of the kind of locations that may result fromthe volunteering process.

Figure 4-1:

Illustration of evaluation of constraints on a site and resulting design
variants. (NUMO, 2004b)

4.2 Operational safety, practicality and logistics
Given the issues raised during the production of the Repository Concepts report, ITAC
considered the NUMO studies of operational safety, practicality and logistics as a very
sensible use of resources prior to a volunteer coming forward. As expected by ITAC, thepracticality of handling compacted bentonite under humid conditions emerged as a major
concern. This was further complicated by the logistical problems caused by the high reference
emplacement rate (five vitrified HLW waste packages per day), which is considerably higher
than in most other national programmes. Indeed, the NUMO material flow analysis provided
a valuable perspective on this area, which quickly showed the limitations of standard H12
designs but indicated that some of the modifications included in the Concept Catalogue (e.g.
pre-fabricated emplacement modules (PEMs), multi-package overpacks) could provide major
gains.
Studies of construction practicality and operational safety also highlighted the issue of using
concrete in emplacement tunnels. As has been seen in other national programmes, this is anarea where there is a conflict in the requirements for operational and post-closure safety.
ITAC agreed with the high priority assigned to this issue in NUMO’s R&D work andconsidered the workshop which was organised on this theme – co-hosted with Posiva – to be asignificant contribution towards coordination of international efforts on this topic (NUMO,
2004c).
ITAC strongly supported studies of the practicality of implementation, as this is a clear
responsibility of NUMO, and also considered that stronger links to assessment of operational
17

safety may be useful, given the problems that conventional accidents have caused in othernational programmes. Even at the early stages of design work, it has to be borne in mind thatthe waste packages have to be emplaced with assured quality using remote handlingtechniques. In case of failure of a package to meet quality specifications – or in other kinds ofoperational phase disruption – waste packages may need to be retrieved, which may involverisks to the staff involved. Designs should thus minimise the risks of recovery being needed
and, as this can never be completely precluded, make the reversal process as simple aspossible. ITAC noted that one important component of such work is development of a
description of operational perturbations that need to be considered during design.
Based on international experience, ITAC also emphasised the value of integrating design deskstudies with full-scale tests in underground facilities. There is a wide programme of relevant
work ongoing in European test sites and NUMO was recommended to maintain its watchingbrief on – and participation in – such work. It was also recommended that NUMO consider
actively testing their own designs – if possible in Japanese URLs but, if that was not feasible,
in facilities run by partner organisations.

4.3 Safety case and advanced performance assessment(PA) for comparison of options
Development of the concept of a broader “safety case” – as a more appropriate goal thanearlier safety assessments based almost exclusively on modelling approaches – occurredinternationally over the period that NUMO was establishing their own ideas on this topic.
Terminology is, however, as yet not consistent across national programmes and ITAC
emphasised that it was important for NUMO to clearly establish its own nomenclature –particularly in Japanese. ITAC considered that NUMO has adopted a sensible definition of asafety case and an appropriate stepwise development process (Kitayama et al., 2007).
Nevertheless, safety case terminology is not well understood in Japan and should be explained
further. This will be particularly important when NUMO documents its plans to develop
safety cases to assist in site selection and later for licensing. A special course organised by thetraining organisation ITC (ITC, 2004) on this topic was attended by senior Japanese experts;
this could be usefully extended in the future to include further technical staff.
In early reviews, ITAC emphasised that the H12 PA approach (JNC, 2000) was inappropriate
for NUMO’s requirements, as it is not capable of realistic comparison of sites and concepts.
General plans for future “next generation” PA code development seem appropriate. Ensuringthat well tested models and databases are available when they will be required is essential for
NUMO and hence such work should be an R&D priority. Even if development is carried out
by supporting organisations, NUMO should take a strong role in providing guidance and, inparticular, ensuring that models are rigorously tested to the level appropriate for eventual
support of a license application. As in the design development work discussed above, ITAC
noted that such testing may require long-term, in-situ "performance confirmation"
experiments: thus, even if the data are required only in the 2030s, establishing long-duration
tests is a task that should be addressed as soon as possible.

184.4 Special design topics – monitoring, retrievability andclosureAlthough the emphasis that NUMO placed on such topics at the early stage of design was
originally considered surprising, ITAC soon realised that it was justified when seen in thecontext of development of regulations in Japan (associated with the L1 interim depth
repository for “high beta/gamma” LLW being investigated at Rokkasho). Given theregulators’ desire to have homogeneous regulations for all disposal facilities, it is importantthat NUMO can provide well thought-out input to the associated debate. International
overviews of the state-of-the-art in these areas were featured in ITAC-11, which also included
detailed discussion on NUMO concepts.
On monitoring, it is clearly important for NUMO to establish plans for baseline monitoring,which needs to be implemented as soon as PIAs are selected. Indeed, compilation of existingdata to support baseline measurements should be a goal of the literature survey. Construction
and operational monitoring can be important components of Quality Management, in addition
to providing opportunities to test site models. More specific performance confirmation
monitoring, particularly for the EBS, is a trickier question. There is ongoing discussion about
whether this is necessary or not – approaches seem to depend very much on national
regulations and perceived needs for public acceptance. ITAC warned that, with existing
technology, there are no safety-critical performance indicators that could be monitored
without risking degradation of performance due to the presence of the monitoring system.
Nevertheless, it was clear that, in case it is required to provide such a system, it is prudent for
NUMO to investigate associated issues now.
The issue of performance monitoring is closely coupled to retrieval. International terminology
is rather loose, but ITAC recommended distinguishing between “reversal” of emplacement –which must be a well established procedure to allow any quality problems to be rectified –and “retrieval” of emplaced waste after tunnels have been filled and sealed. Also, as a matterof both policy and terminology, ITAC emphasised that waste in NUMO’s concepts wasalways retrievable in principle – the differences between design options are associated withthe varying levels of effort and risk associated with recovery of waste at various times after
emplacement. Again, there are considerable differences in positions taken by individual
national programmes. Nevertheless, ITAC thought that NUMO’s plan to examine options ofretrieval up to the point of repository closure seemed a reasonable compromise.
This leads to the process of closure. It was evident that this has not been examined in any
depth in most national programmes, but could be important in Japan due to the pressure toinclude an extended period (maybe 300 years) of institutional control – analogous to thatspecified for surface disposal sites. If such institutional control is required, there are obviously
impacts on approaches to monitoring and retrievability. ITAC agreed that NUMO shouldmake strong arguments that actions should not risk degrading safety barriers and henceemphasis should be on rapidly sealing all repository access and ensuring that site access iscontrolled to prevent perturbations such as drilling. If any performance confirmation isneeded, long-term demonstration projects in a spatially separated URL seemed to bepreferable to anything within the repository zone, although it would be hoped that either
technology would have advanced or acceptance increased to the point that this was not
required.

19

4.5 Technical implications of added TRU responsibilities
Recent expansion of the range of “specified” radioactive wastes managed by NUMO toinclude longer-lived wastes from reprocessing and MOX fabrication (termed “TRU”)
represents a significant increase in the strategic and technical challenges that the organisation
faces (METI, 2007). The former aspects are discussed in section 5.6; here, emphasis is ontechnical issues. As was evident from an international review during ITAC-10, this type ofwaste varies between national programmes but, in all cases, requires very careful management.
Although not inherently more hazardous than HLW, its heterogeneity and chemicalcomplexity make development of a robust safety case more difficult. ITAC emphasised that it
was important that NUMO fully recognised the challenges involved and assured availabilityof sufficient manpower and budget to overcome them.
As a starting-point, ITAC strongly recommended that NUMO re-assessed waste definition
terminology – which is not standardised in any country, but is particularly arcane andconfusing in Japan. For example, there is a huge potential for confusing both domestic andforeign observers by using the term “TRU”, which is conventionally applied to waste
containing ‘transuranic’ or actinide-bearing elements. In some cases in Japan, “TRU” isapplied to those longer-lived wastes other than HLW that require deep geological disposal,
even if such TRU wastes contain no significant actinide concentrations. In other cases,“TRU” is applied to any wastes containing significant level of transuranics (hence statements
like “TRU that goes for near-surface disposal”). It was noticed that even NUMO staff do not
use “TRU” consistently. It is absolutely essential that NUMO can communicate clearly andunambiguously to both Japanese and English audiences and ITAC feels that the importance ofclear terminology cannot be overemphasised.
At a technical level, concepts developed in the past for TRU were examined by ITAC. It wasnoted that the 1st TRU Report (TRU Coordination Team, 2000) included an extensive internal
review, so that this should be considered along with the more recent 2nd TRU report (JAEA
and FEPC, 2007) to provide a starting-point for NUMO's work in this area. In any case, thegeneric concepts in these reports for a preliminary grouping of waste types need to betransformed into a catalogue of options in the way that NUMO did for HLW. ITAC strongly
supports such work, but warned that international experience suggests that this will involve a
lot of innovative thinking for this complex waste type – especially given the boundary
conditions set by the volunteering approach to siting.
The production of a design catalogue for TRU also requires the parallel development ofappropriate, realistic PA codes and databases. The extremely simple “mixing tank” approach
to modelling the engineered barriers in the 2nd TRU report requires major improvement,
supported by more complete specification of waste characteristics and assessment of thedegree of flexibility with regard to conditioning and packaging. This will certainly involve
many challenges. For such waste, complicating factors such as gas, organics, colloids andmicrobes cannot be regarded as minor perturbations, but may play a significant role in theassessment of safety. This would be a priority area for R&D.
The TRU project was put in context at the final ITAC meeting by a visit to the Rokkasho
investigation site. The parallels between the L1 project and NUMO’s TRU disposal are
clearly close and NUMO was recommended to follow technical developments here. Evidenceof links between the L1 project and NUMO teams were encouraging and ITAC recommends
that all opportunities should be taken to extend these. Nevertheless, NUMO should proceed
20

with care when using the L1 project as an “analogue” of a TRU repository. In particular, any
use for public communication purposes should be planned carefully as some near-surface
characteristics of this site (water inflow, rapid corrosion, extensive biological activity) differ
from those sought for a TRU repository.

21

5 Organisational development of NUMO
Although not a main goal for ITAC, the technical aspects of NUMO’s projects could not beeasily separated from organisational aspects and hence ITAC’s input here is documented inthis section.

5.1

Structure and staffing

NUMO is unusual from an international perspective as it was established initially on the basisof limited term attachment of technical staff from “stakeholders” – predominantly the utilities,
R&D organisations and METI. This is not without precedent (e.g. early phase of Nirex in theUK), but the short period of attachment was a major concern for ITAC from the beginning.
International experience shows clearly that radwaste disposal is a complex, multi-disciplinary
field where experience over decades is required in order to integrate the scientific andtechnical basis of repository projects. ITAC has been impressed by the high level of ability of
NUMO’s technical staff and the rate at which they have been brought up to speed.
Nevertheless, the loss of such staff when they have returned to their original employers has
resulted in systematic critical loss of continuity and institutional knowledge, which is alreadya limiting factor in NUMO’s R&D work. It was a recurring recommendation from ITAC that
NUMO examine possible options and inducements to increase the numbers of experienced
staff who are permanently retained.
As is the case worldwide, there are also shortages of experienced staff throughout the nuclear
industry in Japan. ITAC has thus encouraged NUMO to consider how to recruit and train
young staff who would be in a position to take leading roles in the key steps towards licensing
in the 2030s. Certainly, if NUMO had such staff with long-term career prospects, it would
make sense to invest more in training – especially building up “hands-on” experience via
secondment to international partner organisations with ongoing site characterisation projects,
participation in complex URL and natural analogue studies, etc.

5.2 Working Standards and communication with regulatory
bodiesDue to lack of existing regulations, development of internal Working Standards that define
provisional boundary conditions for repository projects is clearly a key issue for NUMO andhas been discussed at several ITAC sessions. In addition, ITAC members (M. Apted, J.
Andersson) also provided direct support on this topic.
An early recommendation from ITAC was that NUMO should build contacts with theregulators and participate actively in the process of development of regulatory guidelines.
There are clear sensitivities due to the need for regulator independence. Nevertheless, it is in
the interest of all involved parties to ensure that regulations are balanced, unambiguous andallow compliance to be clearly demonstrated with a reasonable investment of effort. ITAC
was pleased to note a move towards joint participation in open meetings over the last five
years or so.

22

As noted above, ongoing development of regulations led to focused ITAC technicaldiscussions on closure and monitoring. Another topic that led to a special ITAC session wastimescales for compliance (ITAC-8). This is certainly an area where there is little
international consensus, as the issues involved are not only technical, but also include
regulatory, societal and philosophical considerations. Nevertheless, the specified requirements
for assessment of impacts in the distant future can have large impacts on the repository
programme. This was seen in the case of Yucca Mountain, for example, when the earlier
compliance timescale of 10,000 years was increased to one million years, based on advice on
long-term geological stability from a US National Academy of Sciences review panel(background provided in Appendix 2 of Chapman and McCombie, 2003). Although
discussion in Japan tended to focus on the timescale over which tectonic developments might
be predictable based on extrapolation of current geological conditions (around 100,000 years),as an alternative approach ITAC recommended also considering the timescale over which thetoxicity of high-level (or TRU) waste was greater than that of the original ore used to
manufacture an equivalent quantity of fuel (around 3,000 years). In any case, there are goodarguments for applying the exceedingly strict quantitative dose limits (10 μSv/a) only for alimited time period and, after that, relying more on alternative performance indicators.
In recent years, discussions on regulatory approaches in Japan have tended to focus
exclusively on linking dose limits to scenario probability, although a rational approach also
requires consideration of the timescales involved. ITAC has noted that this is an important
issue for NUMO. For example, uplift and erosion at a repository site in Japan is a highly
probable process and thus, even for relatively low uplift and erosion rates, having therepository at or near the surface will be a probable scenario if there is no limit on the future
timescale that needs to be considered. Experience in other national programmes has illustrated
that it will be extremely difficult to show compliance with a 10 μSv/a limit for such uplift anderosion scenarios. For example, this has been shown in analyses of scenarios in Switzerland
for the case of repository erosion after several million years (Nagra, 2002) and was also
indicated by conservative bounding analyses presented in the H12 report (JNC, 2000).
ITAC also recommended that the current terminology used in the classification of scenarios inJapan be reviewed. For example, it is very difficult to argue anything about the probability ofhuman intrusion – it may be better to simply identify a group of “special treatment” scenarios.

5.3 QA / QMS
Introduction of a quality management system (QMS) was identified by NUMO as animportant issue and was the special topic of ITAC-5. ITAC strongly recommended
implementation of a QMS as soon as possible - but also advocated learning from the positive(and negative) experience in other programmes, for example:• Formal ISO certification is worth considering, mainly due to probable expectations ofregulators and the general public. Nevertheless, certification alone will not cover all of
NUMO’s needs as this tends more to cover processes rather than content – and is thus
inadequate on its own for a complex, multi-disciplinary project.
• NUMO will need to ensure that its QMS is also extended to any supportingorganisations that are providing input for future safety cases. International experience
has indicated that this can require a change of culture in some R&D organisations,which requires significant time and effort to implement.
23

Progress has been regularly reviewed, but a formal QMS has not yet been fully implemented,
since the formal documentation has not been completed. ITAC has noted that the later thisoccurs, the more difficult it is to “back assure” existing data, so this should be a priority for
NUMO before site characterisation commences.

5.4 RMS / NSA
The NUMO initiative to develop a requirements management system (RMS) arose after
intensive ITAC discussion on transparent and documented decision-making for site selection
and tailoring repository concepts to sites (discussed in the previous sections). This was
extended into a rather novel formalised methodology for stepwise tailoring of the entire
programme – referred to as the NUMO Structured Approach (NSA). ITAC was originallyrather sceptical, but gradually recognised that this methodology had merit for NUMO’s
particular boundary conditions. The concepts were intensively discussed by ITAC, who also
reviewed the resulting report documenting this work (NUMO, 2007: production supported by
I. McKinley). Due to its novelty, ITAC recommended publishing information on the NSA in
the technical literature, which resulted in a series of papers (Kitayama et al., 2005b; 2005c;
2006) broadening recognition for this methodology.
While ITAC support the NSA and RMS concepts, caution was expressed on the extent towhich they would be adopted at a working level. It is clear that this requires communicationof the benefits to both NUMO staff and key contractors and implementation of a user-friendly
RMS. This must be assigned high priority if the NSA is to be rigorously applied from thepoint of initiation of the literature studies at volunteer sites.

5.5 Communication and confidence-building
Although the topic of communication is not within ITAC’s main technical remit, this isclearly a key issue due to NUMO’s volunteering approach and, hence, was a topic at several
ITAC meetings. Specifically, at ITAC-9, ITAC learned about the communication efforts
employed by NUMO, involving use of a wide range of media. However, although attempts
have been made, it is difficult to measure the effectiveness of NUMO’s extensive media
campaigns. ITAC’s impression was that one problem is the fact that NUMO communication
is not fully integrated with community outreach programmes by the Government, utilities andother relevant organisations and this seems to limit its impact. Recently, the Government has
committed to providing more support of NUMO’s call for volunteers; however, even morepositive and open communication by top-level Government representatives to encourage
volunteers would be valuable. NUMO itself has also drawn some lessons from the negative
experiences it has had with some communities. The need to react more quickly, to establish
both local contacts and a local presence, is one of the most important points. There should beno time gap in which opposition to volunteering can be built up without NUMO being in aposition to offer competent and rapid responses to public concerns.
Associated with general communication, the topic of building confidence in NUMO as anorganisation has been repeatedly discussed by ITAC. The issue initially was that NUMO wasa new organisation and not well known either nationally or internationally. ITAC has strongly
24encouraged NUMO to be active in the technical conference circuit in both Japan and overseas
and has been impressed at the way the organisation has rapidly established itself as a major
player in the radwaste field. Unfortunately, international success at establishing its "brandname" appears to have been generally greater than that within Japan; also, in both cases, mostrecognition has been from technical stakeholder groups. While this acceptance by thetechnical community is necessary for NUMO to gain both national and local acceptance, it is
not sufficient, and a wider profile is certainly needed in Japan. This is improving withincreased links to media and NGOs, but there seem to be some gaps that could be futuretargets (e.g. communities that host existing nuclear facilities).

5.6 Organisational implications of expanded responsibility
for TRU
The technical aspects of expanding NUMO's responsibility to include TRU waste werediscussed in section 4.5, but, in both the general ITAC sessions and the special TRU topicalsession associated with ITAC-10, administrative and organisational aspects of thisdevelopment were discussed. Although the rationale for NUMO taking responsibility for thisspecified waste is strongly supported, ITAC noted that this needs to be carefully explained tothe public, especially as initial volunteering was intended only for HLW. The documents
expanding the call for volunteers to include TRU must thus be prepared very carefully. For
example, as noted in the previous section, “TRU” terminology must be rationalised. Also, on
the topic of terminology, the term “co-disposal” should be used with care, as possible costbenefits of co-location of disposal facilities are not clearly established as yet. Indeed, this may
be a topic that could be identified as an open issue that would be decided on the basis ofconsensus with potential host communities.
As also previously noted, the technical challenges associated with TRU are significantly
greater than with HLW – which has implications for both communication and manpowerplanning. For communication, it is important not to overstate the hazard of TRU, but it must
be recognised that a site which would be suitable for HLW may not necessarily be acceptablefor TRU. This is a result of the general "over-design" of the HLW EBS, as well as differences
between the characteristics and attributes (including volume) of high-level and TRU wastes.
Care must be taken not to be pressured into assuring “equivalent” EBS performance for TRU.
In any case, close interaction between technical and communication groups is needed to avoid
risks of confusing stakeholders or provoking unreasonable safety comparisons between HLW
and TRU.
On the manpower side, all the arguments above on staffing assume an even greater emphasis
when a parallel TRU programme is taken into account. It is clear that, although there aredifferences between HLW and TRU, there are also some fundamental similarities. From anorganisational viewpoint, therefore, there are both advantages and drawbacks associated withthe options of either setting up separate HLW and TRU groups or integrating responsibility ina single group. The ITAC review showed that there are international precedents for both
options – separation is more common in larger programmes and integration is found in thesmaller ones. In any case, this is a secondary concern compared to assuring that resources ofqualified manpower – which seemed strained even for HLW – are sufficient to adequately
establish a credible TRU programme.

25

6 Conclusions
6.1 Summary of the mission of ITAC Phase 1
The key objective of ITAC during the early years of NUMO's work was to help establish
NUMO as a technically competent and transparent organisation that could successfully
develop a national geological disposal programme for HLW. The issue of winning sufficienttrust of the public and of the technical community was especially important in Japan becauseof the purely voluntary siting process that was adopted by NUMO. Within this mission, themost urgent and important tasks facing ITAC were to advise on, and provide input for, thesolicitation documentation and key supporting technical reports. Subsequent to this first seriesof activities, ITAC has been involved with helping NUMO prepare for the siting andrepository development work that lies ahead. Much input has been given on organisational
issues and on more detailed technical tasks such as site characterisation, engineered barrier
design, etc.

6.2 Current status of NUMO
After several years of development, NUMO has now established its technical credibility inJapan (especially with academics and professional organisations). It has also become a wellregarded organisation within the international waste management community. Its scientificbasis equals that of other national programmes in virtually all areas, with superior expertise in
selected key areas, such as understanding the impacts of tectonics and volcanism. It hasrecognised the crucial importance of quality management and continues to develop its
structured approaches to implementation, supported by appropriate management tools. Also
important is the acknowledged need to recruit, train and retain staff who will serve in the
NUMO team for much longer periods of time than the typically three-year attachments thatwere common in the early days.
The critical objective that has not yet been reached is finding communities that are willing tovolunteer to be considered as potential preliminary investigation areas (PIAs). The lack ofsuccess to date is not a consequence of any weakness or failing in NUMO's technicalprogramme: there has been little or no criticism of NUMO's scientific or engineering design
work, either in Japan or internationally. One reason for this situation may be that the formalityof the solicitation process has made the act of volunteering, even at the first level, appear to
be a very committing step for a local community. Further measures may be possible to lower
the threshold to volunteering. The UK and Canada, for example, have introduced an interim
smaller step into their volunteering processes – a step in which communities are asked only toengage in dialogue with the repository implementer. The UK has also directly addressed thesensitive issue of when and under what conditions communities might withdraw from theprocess. Insights may also be gained by NUMO from studying the long community relations
programmes that have led in Finland and Sweden to local communities democraticallyagreeing to host a geological repository. Addressing the public/political challenges of finding
volunteers in Japan must obviously be the top priority for NUMO at present.
Even after communities come forward, NUMO will be confronted with a range of complex
programmatic and technical challenges. To successfully master these, NUMO will have tocontinue to develop its technical, scientific and management capabilities. For this, it may once
26

again be useful to make use of technical advisors. Accordingly, the current ITAC, to end its
work in Phase 1 of the NUMO programme, has made some comments below on the roles ofadvisory bodies. Rather than making specific recommendations at this time, it has indicatedthe key points that NUMO should consider when it eventually constitutes one or more
technical advisory or review bodies for the coming phases of its work. This is first put incontext by an assessment of NUMO’s future challenges.

6.3 Future challenges for NUMO
Although ITAC has helped NUMO to achieve proficiency and credibility in many technicalareas, there are some important aspects of the Japanese programme that have not yet beenaddressed in the work of the Committee. One example is the production of an overall R&D
plan. The obstacles to preparation and documentation of such a plan have partly been thepressure of the top priority work on the solicitation documentation and partly because there
seems to be a lack of established procedures to ensure overall guidance to, and coordinationof, Japanese R&D in the waste disposal area. In the future, it will be important for NUMO not
only to have its own structured R&D programme, but also to have sufficient influence oversupporting R&D work on radioactive waste disposal that is carried out by other Japaneseorganisations. Another obvious topic that could usefully have been addressed by ITAC
concerns the development of a Japanese concept for Safety Case development. The extensive
expertise of many ITAC members in this area make it regrettable that little time could be
devoted to this important topic in the first phase of ITAC. Further topics to which ITAC
members could obviously contribute include priority work areas in Japan, such as theimplementation concept for TRU and the formulation of new regulations. Concerning thelatter topic, it is noted that NUMO is active in developing open contacts with regulators;
nevertheless, ITAC may have been able to provide further input here, based on the evolutionof, and the lessons learned from, foreign regulatory programmes.

6.3.1 Programmatic challenges facing NUMO
Programmatic challenges facing NUMO include:
•

•
•
•

Reinforcing its siting process (together with the Government) to enhance theprobability of local communities volunteering. As indicated above, there is relatively
little that can be achieved through the technical programme of NUMO, other thanensuring that high quality science and engineering continues to be carried out andpresented in a form that is accessible to all stakeholders.
Detailed design of site characterisation programmes. Although the broad approachhas been studied, any local community that expresses interest will wish to know verysoon exactly what activities will be carried out and to learn of their potential impacts.
TRU disposal. Due to the recently allocated additional responsibility for TRU
disposal, NUMO faces further challenges for its staffing, structures and overall
programme.
Regulatory developments. The regulations covering waste disposal in Japan are still
not completely defined. It is crucial that NUMO remains involved with the work being
done by Government officials in order to provide input on the practicability of

27

•
•

•

proposed regulations and to assess the impact on NUMO work of any standards thatare established.
Internal standards and QMS. A promising start has been made in these areas, but
fully operational methods should be in place, at the latest, before site-specific activities
are begun.
Staffing. The recent initiatives to develop a more stable staff structure and tostrengthen training efforts are very welcome. Continuing pressure must be appliedhere, however, especially if the current rising interest in nuclear power leads toexpanding reactor programmes that will compete with NUMO for good staff.
Building credibility with all stakeholders. This is an ongoing task that requires
personal engagement of all NUMO staff, maintenance of high professional standards,
transparency in all areas of work and implementation of advanced communication
methods to make all stakeholders aware of NUMO's work.

6.3.2 Technical challenges facing NUMOTechnical challenges facing NUMO include:
•

•
•
•
•
•

Repository design concepts. Concepts for TRU repositories or combined HLW/TRU
repositories must be developed, as has been done for the HLW facilities. The concepts
for these facilities must be reviewed and refined to ensure that they are not only
fundamentally feasible, but safe and practical to implement under the boundary
conditions of the Japanese programme.
Safety assessment. As well as developing, documenting and testing NUMO's
approach to preparing a repository Safety Case, it is also necessary to provide focused
support for development of next-generation PA toolkits and databases.
Site characterisation methodology. In addition to the programmatic aspects of siting
mentioned above, specific methodological developments are required – including insitu testing of data gathering and analysis tools and methodology.
Waste Acceptance Criteria (WAC). NUMO should work towards defining WAC
based on preliminary safety assessment of specific waste types in a model deep
repository (particularly important for TRU).
Tectonics/long-term stability. In the Japanese environment, these will continue to beareas of earth science in which NUMO must keep abreast of, or indeed push theleading edge of, the scientific state-of–the-art.
Development of concepts for monitoring, sealing and repository closure. Althoughthese activities lie far in the future, NUMO should have an agreed policy and technicalposition that can be discussed from the earliest stages in the siting process, since these
topics have been seen to be raised in numerous national disposal programmes and areunder discussion for the regulation of the Rokkasho L1 project.

6.3.3 Why a pause and a re-structuring?
Given that the sections above describe outstanding challenges and identify areas where thecurrent ITAC believes that it has contributed less than it might have done, an obvious
question is why it has been decided to close down the current Phase 1 of ITAC.

28

The principal reason is that the original function of ITAC, namely the transfer of usefulexperience and knowledge from established waste management programmes, has been largely
accomplished. The size and the membership of ITAC for its first phase were determined bythis main goal. Having built on this past technical global experience, NUMO is now one of
the leading disposal organisations and has a range of bilateral collaboration agreements withpartner organisations worldwide. Today, volunteer siting is the key hurdle for NUMO, rather
than establishing its technical credibility. If NUMO continues to seek advice from otherprogrammes, the emphases will be on strategic and communication issues. When potential
siting areas have been identified, so that active site characterisation and repository design
work can move ahead, a different approach to utilising international and national advice fromtechnical experts may be more appropriate than the large, relatively infrequent meetings thathave been a feature of recent ITAC work. It is also questionable whether separation of ITAC
from the domestic committee (DTAC) is an effective way to provide the best support for
NUMO.
Recognising these points, the present ITAC devoted some of its final meeting to pooling ideas
on how NUMO might best organise its external expert group structures when a second phaseis initiated. The assembled suggestions are documented below.

6.4 How might the value of future advisory or review
committees be enhanced?
6.4.1 Factors influencing the choice of structures
There are diverse factors which can affect the implementer’s freedom and choices in defining
its own advisory or review bodies. These can be broadly grouped into those relating to thenational framework and culture and those determined primarily by the stage to which thedisposal programme has developed.
National boundary conditions:
The national legal or regulatory framework may impose external review requirements on theimplementer. For example, the CNE in France and the NWTRB in the USA were created bypolitical bodies to overview the waste management agencies. Pre-existence of suitable expert
bodies may also lead to natural choices for advice or review of national programmes (e.g.
Academies of Science or professional and scientific societies). When the implementer sets out
to create its own advisory bodies, a key factor will be its own size and in-house competence.
A small, newly created implementing body, such as NUMO was in 2001, will obviously havemore need for external advice. A large organisation such as the USDOE, which also hasaccess to an extensive national research laboratory infrastructure, may need fewer external
advisory groups. The strength and operational methods of the regulatory body can also
influence the implementer's choice of advisors. If there is a strong regulator carrying out open,
comprehensive review work, then the implementer itself may need to organise lessindependent review – or alternatively it may need more external support in order to prepare its
eventual license application and respond competently to the regulatory review.
Other overarching features of the national programme may also influence the implementer's
choice of expert group structures. One example is the extent and usefulness of agreementswith its foreign sister organisations. Today, most major national waste management29

programmes have bilateral and/or multilateral formal agreements with their counterparts inother countries. This arrangement provides a useful vehicle for exchange of information andexperience. Maximum benefit will be gained from this, however, only if the partners are fully
open in their exchanges and also if they are prepared to both give and accept critical commenton their programmes. Finally, obvious national attributes that influence approaches toexchange of expertise are the cultural and language differences between nations. As described
early in this report, one of the criteria for selection of the original ITAC members was aninterest in, and prior knowledge of, the Japanese programme. This greatly eased the technicalwork and also the personal relationships between members and NUMO staff. Nevertheless,the language barrier remains a particular problem and, as is the case in countries such as
Sweden and Finland that have similar difficulties, production of key documentation in
English may be required in order to ensure that it can be subject to wide enough peer review.
Stage of programme development:
The maturity level of a national waste management programme clearly strongly affects its
requirements for external expert advice. The start-up (or restart, in the various cases where
programmes have been suspended) of disposal organisations is a time at which broad advice
is most important. This was clearly recognised at NUMO when it was created and at NWMO
and NDA in, respectively, Canada and the UK when these programmes were re-launched.
Major programme milestones, such as site selection, may also be decision points at which
overarching external advice and review can be useful. When a programme is in a fully
operational mode, then the most useful type of advisory or review input may be from small
groups or individuals (national and international) who are acknowledged experts in specifictechnical areas.

6.4.2 Future NUMO external expert groups
ITAC has compiled a "check-list" of issues for NUMO to consider when deciding on its
future external expert support. This list is provided below:
NUMO-specific issues:
•
•

•
•

Current technical competence level of its own staff: Are there gaps in NUMO'stechnical capabilities? Are there junior staff members who could benefit from being"mentored" by experienced external advisors?
Current technical and public credibility of its own organisation: Does NUMO
have sufficient staff with the stature to represent its programme on the national andinternational stages? Could it benefit from association with well known experts inspecific technical or societal areas?
Current NUMO priorities: The urgent challenges are related to the siting process andto the impacts of expanded TRU responsibilities. Does NUMO require external advice
on how best to tackle these issues?
Continuing need for knowledge transfer from foreign work: Are the existing
NUMO bilateral agreements together with interactions in international bodies (e.g.
IAEA, NEA, EDRAM) now a sufficient means for ensuring knowledge transfer? If not,what specific gaps can be identified?

30

Structural and organisational issues:
•

•
•
•
•

Splitting expert groups according to support functions: Would it be more efficient
to separate regular “hands-on” support from independent review and strategic advice?
What should be the extent of segregation between review, advice and assistance roles?
What are the pros and cons of panels of experts in ad-hoc advisory groups compared tostable, long-term groups?
Scope of terms of reference of advisory groups: Should strategic, programmatic,
technical, and societal issues be separated or is it more effective to have integrated
groups?
Choice of advisors: One should first agree the definition of the expertise sought inany group, then consider any other requirements of members and only then begin
selection of members.
How to use advisors/reviewers to assess quality of (or give the ‘stamp of approval’to) essential supporting work done by other Japanese organisations.
Integration of advisory and review groups into the overall Japanese waste
management system: Advice and review should be integrated into the overarching
NUMO QMS, which applies also to work carried out by supporting R&D
organisations. The appropriate level of contact between international advisors andDTAC and/or the Japanese scientific community must be decided upon. The same
applies to the level of contact between advisors and other Japanese stakeholder groups– especially regulators.

Modus operandi of expert groups:
There are numerous basic organisational questions to be considered, for example frequency of
meetings, terms of office, coping with the strain on internal resources, use of translators to
overcome language barriers, use of video-conferencing, etc. However, there are also very
important points of principle concerning the functioning of an expert group. These include:•••

How to identify potential bias or conflicts of interest of advisors in order to avoid ormanage such conflicts (this was not a problem for ITAC, but is clearly more sensitive
for a group with an independent review role)
Whether review monitors should be used to ensure transparency and completeness inhandling review comments (commonly a requirement if such review is a component of
a QMS)
Whether the input provided by external experts is to be kept internal or to be publishedin some form (varies according to role: review input may require open publication
whereas technical support may involve other issues, such as intellectual property
rights).

6.4.3 ITAC views on future expert groups
ITAC has been valuable for NUMO in various ways. The Committee has provided review,advice and also direct assistance. As described above, it is understandable that ITAC Phase 1
is being closed down now that past knowledge has been transferred from foreign programmes
and NUMO’s external contact network has become established. ITAC believes, however, that
NUMO would benefit from future use of advice and support from international experts inorder to respond to the major project challenges that lie ahead (see section 6.3). Such experts
may also form a more intimate link to national programmes that are developing rapidly,31

providing efficient access to new knowledge and experience in key areas (e.g. repository
engineering, site characterisation, licensing). As NUMO moves closer to key programme
milestones (selection of PIAs, DIAs and a final site) and eventual licensing, the need forindependent review becomes more critical and, from experience in other national programmes,
this may require accessing resources of international manpower. A further, not insignificant,by-product of the existence of a formal review body is that it provides a point of focus for
NUMO’s project staff and encourages periodic, structured summaries of programme status.
Based on its experience in several years of working with NUMO, ITAC has made somesuggestions that may help structure future advisory bodies.
A key issue concerns the links between internal review, independent “external” review,advice and direct assistance. Although these can be separated, review is clearly a valuableprecursor to advising and gives advisors a good overview. NUMO needs both review (as partof its QM system) and advice. It is not necessary for NUMO to separate review and advisory
roles – but, if NUMO claims a review is fully independent, it may be necessary to go outside
their advisory groups (e.g. NEA, IAEA, ad hoc committees). It is also not necessary toseparate advice from direct assistance, although potential conflicts of interest need to becarefully managed. In short, ITAC experience has shown that members of the same group canfill a range of review, advice and assistance roles, if carefully managed. To make best use ofresources, NUMO should ensure that requests for expert support are specific, well definedand focused on addressing identified NUMO problems. A well integrated group could,
however, also work closely with NUMO to identify specific problems; this would be valuable
for NUMO and also satisfying for the advisors.
A further important consideration is the strength of the connections of NUMO expert groups
to other groups. NUMO's own groups should have some level of inter-connection. Although it
is difficult to fully integrate international and national groups completely, owing to language
barriers, ITAC experience with DTAC has shown that interchange is valuable whenever it ispractical. Indeed, the support role of individual ITAC members has clearly shown that mixed
Japanese / foreign teams can function effectively and, although needing to be carefully
managed, there is no fundamental barrier to closer integration of expert groups. It could also
be productive if NUMO and its advisory groups were to have discussions with regulatory andother organisations, e.g. in the framework of joint workshops to consider boundary conditions
for regulations.
Several possible structures are conceivable for future NUMO expert bodies. Review groups
and their roles should be specified within NUMO’s quality management plan. In terms ofproviding advice, one option is a single strategic overview group and several topical specialist
groups. The specialist groups may have more specialised sub-groups or individual technicalexperts for particular areas. In any case, at the current NUMO programme stage, the focus
should be on relevant scientific disciplines (or interdisciplinary expertise) rather than wide
coverage of foreign programmes. Nevertheless, experience from individual national
programmes may be targeted, chosen in terms of their direct relevance to NUMO’s current
priorities.
For overview groups, an important question is whether they cover programme strategy andintegration in both technical and non-technical areas, or – like ITAC – are formally confined
to technical issues. For specialist groups, there are numerous potential areas of application in
the NUMO programme, e.g.
32

•
•
•
•

repository designs and EBS behaviour
site characterisation methodology and techniquessafety case development and presentationsocietal interaction and communication.

NUMO has, in its first years of activity, made very intelligent use of input from international
advisory experts. As a mature waste management programme, its requirements for external
advice are now different – at present strongly determined by its siting programme. When thepace and direction of the NUMO programme become clearer, then it would, in the view of thepresent ITAC, be beneficial for the Japanese programme if NUMO were to establish further,re-structured advisory bodies to help it address the challenging tasks ahead.

33

7 Acknowledgements
The members of ITAC would like, above all, to thank NUMO staff for providing them withthe opportunity to help establish NUMO as one of the world’s foremost waste disposalorganisations. All members gained an increased knowledge of the Japanese programme andalso close and enduring technical contacts to NUMO colleagues. Equally valued by ITAC are
the close and enduring personal relationships with NUMO colleagues and with their fellow
ITAC members. Not least, we are grateful that we have, over the years, gained some
additional appreciation of the Japanese culture and way of life.

8 References
Apted, M., Berryman, K., Chapman, N., Cloos, M., Connor, C., Kitayama, K., Sparkes, S. and Tsuchi,
H. (2004): Locating a Radioactive Waste Repository in the Ring of Fire, EOS, Transactions,
American Geophysical Union, Volume 85 Number 45, P. 465 and 471, 9 November 2004.
Connor, C., Chapman, N.A., Connor, L. (Editors) (2009): Volcanic and Tectonic Hazard Assessment
for Nuclear Facilities, Cambridge University Press, 2009.
Chapman, N.A., McCombie, C. (2003): Principles and Standards for the Disposal of Long Lived
Wastes, Elsevier.
Chapman, N.A., Goto, J. and Tsuchi, H. (2007): Likelihood of Tectonic Activity Affecting theGeological Stability of a Repository in Japan: Development of NUMO’s ITM Methodology,
NEA-IGSC Geosphere Stability Workshop, 13-15 November 2007, Manchester, UK.
Defra (2008): Managing Radioactive Waste Safely, A Framework for Implementing Geological
Disposal, A White Paper by Defra, BERR and the devolved administrations for Wales andNorthern Ireland, June 2008, Department for Environment Food and Rural Affairs (Defra), UK.
Goto, J., Tsuchi, H., Chapman N. and Kawamura, H. (2008): Siting Japan’s HLW Repository 2:
Addressing the Tectonic Issues in Probabilistic Approach, 33rd International Geological
Congress (33rd IGC), 6-14 August 2008, Oslo, Norway, Abstract CD-ROM.
ITC (2004): The Role of the Safety Case in Planning and Implementation of a Repository Programme,
Assuring Confidence in the Safety of Geological Repositories, 3-4 December 2004, Tokyo, Japan,
School of Underground Waste Storage and Disposal; ITC, Switzerland.
JAEA and FEPC (2007). “Second Progress Report on Research and Development for TRU Waste
Disposal in Japan –Repository Design, Safety Assessment and Means of Implementation in the
Generic Phase”, Japan Atomic Energy Agency and Federation of Electric Power Companies ofJapan, JAEA-Review 2007-010, FEPC TRU-TR2-2007-01.
JNC (2000): H12 Project to Establish the Scientific and Technical Basis for HLW Disposal in Japan,
Project Overview Report, 2nd Progress Report on Research and Development for the Geological
Disposal of HLW in Japan, JNC Technical Report TN1410 2000 001, Japan Nuclear Cycle
Development Institute (JNC), Tokai-mura, Japan.
Kitayama, K., McCombie, C. and Ohe, T. (2005a): Strategies for Technical Confidence Building in
the NUMO HLW Disposal Programme, International Conference on the Safety of Radioactive
Waste Disposal, 3-7 October 2005, Tokyo, Japan.
Kitayama, K., Umeki, H., Ueda, H., McKinley, I. G. and Kaku, K. (2005b): A structured approach for
stepwise tailoring of repository concepts to volunteer sites, Proc. ICEM'05, The 10th International

34

Conference on Environmental Remediation and Radioactive Waste Management, 4-8 September
2005, Glasgow, Scotland.
Kitayama, K., Ueda, H., Sakabe, Y., Umeki, H., McKinley, I. G. and Kaku, K. (2005c): A structured
approach for stepwise design of HLW repositories tailored to volunteer sites, Proc. International
Conference on the Safety of Radioactive Waste Disposal, 3-7 October 2005, Tokyo, Japan.
Kitayama, K. (2006): NUMO’s Winning Team: a goal-oriented approach to gain the confidence of all
stakeholders, Radioactive Waste Management, 12-14 June 2006, London, UK.
Kitayama, K., Ishiguro, K., Takeuchi, M., Tsuchi, H., Kato, T., Sakabe, Y. and Wakasugi, K. (2007):
Strategy for safety case development: Impact of volunteering approach to siting a Japanese HLW
repository, OECD Nuclear Energy Agency International Symposium: Safety Cases for the Deep
Disposal of Radioactive Waste: Where do we stand?, 23-25 January 2007, Paris, France.
METI (2000): Law Concerning the Final Disposal of Specified Radioactive Waste (Law No. 117, June
7, 2000).
METI (2007): Specified Radioactive Waste Final Disposal Act, Ministry of Economy, Trade andIndustry, June, 2007, Tokyo, Japan.
Nagra (2002): Project Opalinus Clay Safety Report, Nagra Technical Report 02-05, Nagra, Wettingen,
Switzerland.
NDA (2008a): NDA Consultation on a Public and Stakeholder Engagement and Communications
Framework for Geological Disposal. Nuclear Decommissioning Authority, Didcot, UK.
NDA (2008b): Proposed Research and Development Strategy, Nuclear Decommissioning Authority,
Didcot, UK.
NUMO (2004a): Evaluating Site Suitability for a HLW Repository, Scientific Background andPractical Application of NUMO’s Siting Factors, NUMO Technical Report NUMO-TR-04-04,
Nuclear Waste Management Organization of Japan, August 2004, Tokyo, Japan.
NUMO (2004b): Development of Repository Concepts for Volunteer Siting Environments, NUMOTechnical Report NUMO-TR-04-03, Nuclear Waste Management Organization of Japan, August
2004, Tokyo, Japan.
NUMO (2004C): Proceedings of the International Workshop on Bentonite-Cement Interaction in
Repository Environments, 14-16 April 2004, Tokyo, Japan, NUMO Technical Report NUMOTR-04-05, (equivalent to POSIVA Working Report 2004-25), Nuclear Waste Management
Organization of Japan, October 2004, Tokyo, Japan.
NUMO (2007): The NUMO Structured Approach to HLW Disposal in Japan, NUMO Technical
Report NUMO-TR-07-02, Staged Project Implementation at Volunteer Sites Utilising a
Requirements Management System, Nuclear Waste Management Organization of Japan, July
2007, Tokyo, Japan.
NWMO (2008): Moving forward together: designing the process for selecting a site. Nuclear Waste
Management Organization, Toronto, Canada.
TRU Coordination Office (2000): Progress Report on Disposal Concept for TRU Waste in Japan, JNC
TY1400 2000-002, TRU TR-2000-02, March, 2000, Japan Nuclear Cycle Development Institute(JNC), Tokai-mura, Japan, The Federation of Electric Power Companies, Tokyo, Japan.
Tsuchi, H., Goto, J., Chapman N.A. and Kawamura, H. (2008a): Tectonic Hazard and the Siting ofJapan’s HLW Repository: preliminary results of ITM’s Tohoku Case Study in the ITM project,
Proceedings of the 12th International High-Level Radioactive Waste Management Conference(IHLRWM), 7-11September 2008, Las Vegas, Nevada, p. 134-141.
Tsuchi, H. and Goto, J. (2008b): Siting Japan’s HLW Repository 1: Addressing the Tectonic Issues in
Deterministic Approach, 33rd International Geological Congress (33rd IGC), 6-14 August 2008,
Oslo, Norway, Abstract CD-ROM.

35

Acronyms and abbreviations:
Arius: Association for Regional and International Underground Storage
CNE: National Review Board, independent evaluation body for the R&D programme concerning
waste management in France
DI: Detailed Investigation
DIA: Detailed Investigation Area
DTAC: Domestic Technical Advisory Group (of NUMO)
EBS: Engineered Barrier System
EDRAM: The International Association for Environmentally Safe Disposal of Radioactive Materials
EFQ: Evaluation Factors for Qualification
FF: Favourable Factors
GIS: Geographical Information System
H12: JNC project to establish the scientific and technical basis for HLW disposal in Japan(documented in JNC 2000)
HLW: High-level waste; in the Japanese context this is vitrified waste from reprocessing of spent fuel
IAEA: International Atomic Energy Agency
ITAC: International Technical Advisory Committee (of NUMO)
ITM: International Tectonics Meeting; a NUMO project to develop an advanced understanding of
volcanism and tectonics
JAEA: Japan Atomic Energy Agency
JNC: Japan Nuclear Cycle Development Institute (integrated into JAEA together with JAERI (Japan
Atomic Energy Research Institute) in December 2001)
JNFL: Japan Nuclear Fuel Limited
L1: JNFL project for intermediate depth disposal (50-100 m) of “high beta/gamma" radioactive waste
LLW: Low-level waste; in the Japanese context, this includes all waste with significant radioactivity
that is not classified as HLW. It is operationally sub-classified depending on source andconcentration of radioactivity in the waste and thus, formally, also includes TRU
METI: Ministry of Economy, Trade and Industry
MOX: Mixed oxide fuel (U-Pu reactor fuel using recycled material from reprocessing)
NDA: Nuclear Decommissioning Authority (UK)
NEA: Nuclear Energy Agency of the OECD (Organisation for Economic Cooperation andDevelopment)
NEF: Nationwide Evaluation Factors; included in EFQ
NGO: Non-Governmental Organisation
NWTRB: Nuclear Waste Technical Review Board (USA)NWMO: Nuclear Waste Management Organization (Canada)
NSA: NUMO Structured Approach
NUMO: Nuclear Waste Management Organization of Japan
PA: Performance Assessment
PEM: Prefabricated EBS Module
PI: Preliminary Investigation
PIA: Preliminary Investigation Area
PNC: Power Reactor and Nuclear Fuel Development Corporation, precursor to JNC
QA: Quality Assurance
QMS: Quality Management System
RMS: Requirements Management System
RC: Repository concept
RS: Repository Site
SF: Siting Factors
SIA: Supplementary Investigation Area
SSEF: Site-specific Evaluation Factors; included in EFQ
SHP: Steering Committee on High-level Radioactive Waste Project
TRU: The Japanese term for non-HLW with sufficiently high toxicity that it requires deep geologicaldisposal, arising predominantly from reprocessing and mixed oxide fuel fabrication

36

URL: Underground Research Laboratory
USDOE: United States Department of Energy
WAC: Waste Acceptance Criteria
WIPP: Waste Isolation Pilot Plant (USA)37