ITAC 11 Short Record

NUMO International Technical Advisory Committee
Short Record of the ITAC-11 Meeting
Tokyo, 27 - 29 November 2007
General Remarks
President T. Yamaji welcomed ITAC and summarised some major developments at
NUMO since ITAC-10. Key aspects included a concerted effort on building
relationships with local communities and development of plans for TRU disposal,
making use of experience available from other countries. The justification for closure asa special topic for this meeting was explained, noting the need to initiate staged
development of site-specific closure concepts as an important component of guiding site
selection and preparation for eventual licensing. The impact of the withdrawal of the
Toyo-cho application and the resulting change in Government policy, moving towards amore active solicitation process, was highlighted and the planned R&D forum (January
17th 2008) was mentioned.
The special focus of the meeting was an examination of processes associated withrepository closure (Block 4), which is a topic of considerable interest in Japan at present
in the light of discussions of the regulatory requirements for licensing. The extensive
information resulting from this session illustrates how NUMO is making effective useof ITAC. The input given by ITAC may be of wider interest in Japan and thus could bemade available to other interested parties (e.g. JNFL, regulators).
A further special session covered relevant topics outside of NUMO’s direct remit(Block 3). ITAC considered these presentations valuable to put the NUMO work incontext. In particular, the link between the Rokkasho L1 project and NUMO’s expanded
requirement to include geological disposal of TRU will inevitably lead to a certain
degree of coupling of these projects and so this status review was very timely.
A general question involved technical publications: there seems to be a need for NUMO
to consider more active distribution of external reports from their R&D programme –although it was noted that NUMO produces many papers at conferences. This is an area
where ITAC may be able to help with review (and such documents would help ITAC tobe well informed about progress in key areas). Although the effort of producing quality
external publications is considerable, it can be very cost-effective in terms ofestablishing credibility. Kitayama indicated that NUMO would produce interim reports
periodically, which would document the progress of such studies.
Block 1: National news from HLW / SF / TRU programmes
As in the last ITAC, the meeting commenced with short overviews of recent news fromthe ITAC members.
Block 2: Highlights of NUMO activities since ITAC 10
Current Status of NUMO R&D (K. Kitayama)-1-

ITAC 11 Short Record

The presentation considered 3 items:•

TRU disposal; now included in NUMO’s remit by an amendment to the Nuclear
Law. The definition of this waste is effectively LLW that requires deep geologicaldisposal although present focus is on arisings from reprocessing and MOX
fabrication. Emphasis is on bringing the level of TRU repository concept to a level
equivalent to that of HLW.

•

Regulatory developments (NB also presentation by Yoshizawa below)•oFundamental regulatory concept – framework is developed which does notformally involve review of the siting process, but this is encouragedoRegulatory process is also being defined which includes safety reviews,
procedures for closure and process of ending regulatory control. More active
involvement of the regulator throughout the siting process is recommended, as
is the formation of a special review board

R&D programme, which is complicated in Japan by the number of R&D
organisations involved, includesoEmphasis on advanced planningo

Operational and post closure safety assessmentoLong-term evolution of the plan, with technical standards being reviewed atregular intervalsoImplementation philosophy – NSA. Report issued during the summer (07-02)
which summarises how NUMO can in a flexible and transparent manner tailor
its entire programme to the sites that come forward. This also produces, as
output, an R&D plan that is updated at regular intervals.

oPresent goals includeTesting characterisation plans (PIMM, PIPM) in the fieldDeveloping of disposal technology; practicality and operational safety

Establishing the process of repository closureExtended technical public information programme

Subsequent discussion included planning of R&D; need for stronger NUMO role on
Coordination Council for R&D on Geological Disposal seemed important, but the exact
composition and working process of this organisation was rather unclear.
Direct R&D to establish the tools to support the site selection process was not clearlyshown; this is incorporated within the NSA, but it is not very clear how the priorities forwork are established. The need for studying repository closure is justified, but its
relative weighting compared to other input that is needed earlier is still unclear.
Publication of R&D; only small numbers of reports are produced in 2006 and 2007 in
the NUMO-TR series –ITAC believes that this should be expanded to improvecredibility. Post-closure monitoring; requirements are uncertain internationally andhence flexibility may be needed (as accepted by the NSA).

-2-ITAC 11 Short Record

In general, there is uncertainty about the overall balance of both NUMO’s science andtechnology strategy and the Japanese national R&D plan supporting deep geologicaldisposal (in house and carried out by other organisations). NUMO has presented
highlights of ongoing work, but not illustrated an integrated programme. This could
reflect external constraints imposed on NUMO’s S&T work and the imbalance in thesize of the R&D budgets for different organisations.
ITAC could function more effectively if the S&T implementation strategy and the way
in which this leads to specific R&D programmes (1 year, 5 year, longer?) could be
explained.
ITAC could potentially help review and suggest improvements to develop an optimised
R&D programme via:
¾ Direct interaction with experts from the government side
¾ Intensive workshop (NUMO & external) on the R&D programme¾ Interdisciplinary, multi-organisation working groups¾ Special session on safety assessment strategy and associated R&D needs¾ Identify NUMO R&D projects that can run independently from siting efforts
Current siting and public information activities (M. Futakuchi)
The presentation showed the future activities to promote the public understanding of
HLW geological disposal, based on the experiences of activities in Toyo-cho etc., to getvolunteers for the literature survey. As for the future activities, based on theirexperiences in each nation, ITAC members made constructive advices to NUMO, andthe members and NUMO exchanged opinions.
Requirement Management System (H. Ueda)
The presentation started with an overview of the background to the RMS and its place
within the NSA. The advanced “N-RMS” as implemented in the computerised tool istailored to NUMO’s particular needs and has particular focus on supporting decision
making. The current trial system intends to illustrate:•

Management of decision-making•

Change management•

Efficient feedback to project planning (e.g. R&D)•

Structured record keeping

As spin-off, it may help presentation of projects to stakeholders and education of new
NUMO members. The trial is applied to general management of technical projects,
development of repository concepts and site evaluation / selection. Coding hascommenced in the first two areas. At the end of the FY, the system will be assessed interms of practical application.
In general, it was considered that:-3-

ITAC 11 Short Record¾ The basic idea is good and it is certainly valuable to clearly record decisions¾ Emphasis should be on applications rather than software, e.g. considering theeventual need to tailor concepts to sites - which needs a wider viewpoint than thetight focus on EBS components¾ ITAC would like to see more about practical applications and how it handles
realistic decision-making (e.g. in a dynamic system where change management isimportant)¾ Safety assessment could be represented more explicitly in the process¾ Exact relationship between this work and the very closely related information flow
system for geosynthesis (JAEA) might be worth clarifying
In any case, this project could be important and may be worth ITAC spending moretime on this at a future meeting.
Government and ministerial ordinances; progress of institutionalization for TRU
waste disposal (Y. Yoshizawa)
The presentation traced the evolution of laws and associated regulatory procedures since
definition of HLW as specified waste, through expansion to cover TRU and also the
expected development until repository licensing. In particular, the contents of the NISA
regulatory framework for geological disposal report were outlined. This complements
the law on regulation of nuclear material – which moves towards more consistenttreatment of different disposal projects. Some key issues arising from suchdevelopments for NUMO are:•

QMS development and implementation•

Post-closure safety confirmation•Role of monitoring•

Periodic reviews•

Safety case content.

In terms of the overall TRU programme (including input from the R&D presentation):¾ Formal allocation of responsibility for this waste to NUMO is sensible, allowing
opportunities for optimisation of deep disposal activities¾ Terminology for TRU and other long-lived ILW is confusing and needs to berationalised for all use in Japan¾ TRU has technical overlaps with, but is more technically challenging than, HLW¾ This requires increased staffing and budget; opportunities to optimise use of limited
resources should be considered, which may require structural changes¾ ITAC could provide more detailed technical support in this area
Block 3: Non-NUMO activities relevant to deep geological disposal-4-

ITAC 11 Short Record

Summary of Niigata Chuetsu Offshore Earthquake (T. Oouchi)
The summary of this event was placed in the context of regional setting, explaining why
this earthquake – which was not particularly large or destructive by Japanese standards– caused such concern. The fact that a large earthquake could occur in a site extensively
characterised for NPP siting clearly raises concerns in any potential siting community inJapan.
The effects of this earthquake on the plant were very small considering that the peakaccelerations were well above design specs. Despite this very positive news, thehandling of public communication by Tepco appears to have been poorly managed –contributing to the negative reporting worldwide of this event.
In context, NUMO considers that such an event would cause concerns only during theoperational phase – when it could be handled by conventional seismic design. The
assumption of an ability to detect active faults is not compromised by this event andthus they could still be avoided during siting. This event has, however, caused initiationof a lot of new research, which will be followed by NUMO. This fits in with NUMO’s
own work on dating fault movements and the general work by the ITM group andillustrates also the advantages of the high density of seismic data / dense GPS network
in Japan.
Such detailed technical analysis, including a critical evaluation of vertical seismic
profiles, was considered by ITAC to be valuable and demonstrates NUMO capability toreact in a professional way to questions by both the general public and international
partners, which is an important aspect of technical confidence-building. Presentation
could, however, also emphasise survival of properly engineered structures.
Status of the Rokkasho L1 project (TEPCO K. Kato)
The valuable update of this project was useful to illustrate its coupling to their TRU
remit – which needs to be carefully followed by NUMO staff. This was appreciated by
ITAC, who are looking forward to visiting this facility at some time
Block 4: Planning repository closureThis session comprised 3 components¾ an international review of the situation in national programmes by ITAC members
focusing on requirements for closure and the processes associated with transfer of
liabilities and any other responsibilities, for example with regard to monitoring andretrievability (much of which is not well documented in the open literature)¾ a summary of the NUMO position on this topic¾ a structured open discussion.
a) The international presentations are summarised in the appended matrix and key
points raised by the similarities and differences involved are integrated into thediscussion of the situation in Japan as presented in (b) below.
-5-

ITAC 11 Short Recordb) The NUMO position
Status of NUMO considerations of the topic (Y. Takahashi)
The amended act requires that a closure plan should be developed by the implementerand approved by METI before repository closure – unfortunately the definition ofclosure is rather vague. This is important because the current operational plan foresees
construction, operation and closure processes going on in parallel in different panels.
NUMO currently defines closure as the process after all waste has been emplaced; thebackfilling and sealing of individual panels is considered to be part of “operations”.
Confirmation of safety before closure is a key issue – already identified in NUMO TR04-03 as requiring an extensive, focused monitoring programme.
The requirements of the closure plan have been outlined by NISA (based on IAEA),
considering both contents (processes and confirmation procedures) and the proceduresfor submission and review of the plan – including confirmation by the regulators that itis properly implemented.
NUMO plans a specific closure phase after emplacement ends, which may include
extended monitoring. Retrievability will be required during the operational phase, but it
is not yet decided how long this requirement is needed.
The final decision on closure is based on assurance of safety. This may be based on the
results of safety reviews, assurance of the efficiency of the sealing system and safetyassessment based on experience gained during operations. The latter may need a special
consideration of differences between the safety case at the time of licensing and thefinal case for closure. Here the RMS may provide a very valuable record of suchdevelopment.
Considering NUMO’s upcoming programme milestones, generic closure concepts will
be gradually tailored to sites as information increases during LS, PI and DI stages. The
effectiveness of the sealing system will be an important part of the evolving site specificsafety cases – as specified in the NSA.
Retrievability is not considered in Japan based on potential future value of the waste – itis only needed to allow a response to possible safety concerns identified during
monitoring and thus is needed only until closure – although it is acknowledged to bepossible thereafter.
Monitoring pre-closure is an essential part of QA, assuring operational safety, guiding
responses to accidents and building a post-closure safety case. Post-closure monitoring
may be needed for public acceptance; this is not linked to possible waste retrieval –which could occur only for other reasons (e.g. technological advances). The option of asmall amount of waste being intensively monitored specifically to support closure has
not yet been discussed beyond the possibilities of appropriate technology development
for such monitoring in the DIA URL.
Extended discussion on monitoring technology (with reference to the Japanese work
carried out by RWMC) noted that a lot of progress is being made in this field, although
there are still open questions when the focus is on long-term safety confirmation.

-6-

ITAC 11 Short Record

Post closure monitoring – a summary of national positions:•

Switzerland – not by Nagra; open for the Government, but not planned•

USA/WIPP – carried out, but only for public acceptance. The only safety criticalmonitoring here is assurance of no intrusion.

•

France –no monitoring planned as yet, but some may think that it could be needed
for PR (as such monitoring is carried out for 300 years in the case of surface
disposal). In any case, closure must be approved by law (therefore after the “at least
100 years” reversibility period) and at this time, it will be decided.

•

UK – no need identified by regulator, but accepted that may be needed for public
acceptance (under the boundary conditions in the future when this happens)•

Sweden – not required by regulations, but left open by SKB (until time of closure)•

USA/YMP – no safety requirement by regulator but a commitment by DoE (surface
based) although details left open•

Germany – no regulatory requirement•

Canada – regulator allows for monitoring being part of the safety case (needed formill tailings) and left open for other types of waste and may be a societal
requirement•

Finland – no specific decision, up to Government that may order a one-time
payment to cover costs.

•

NUMO – monitoring for 300 years already decided for Rokkasho and this leads to a
Government budget for this PR work of 100M JPY / year for 300a (calculated using
a 3% interest rate).

Retrievability; in Japan discussed only at a technical level by regulators, but social
aspects already considered by NUMO. There is a wide range of requirements worldwide
and different weightings on the PR aspects. It should, however, be emphasised that all
waste is retrievable in the concepts considered – the only differences involve the costs
and risks involved. There are also arguments for the benefits of irretrievability –certainly for types of waste that are not potential resources in the future (strong
distinction between SF and HLW).
The debate on retrieval for social reasons should maybe concentrate more on the total
picture of the operation of the repository – which may mean that emphasis should be on
the wide spectrum of options available. Special emphasis could be on options that allow
inspectability. There are ranges of pros and cons even for technical aspects(retrievability of spent fuel), which again argues for maintaining a range of options andvariants.
Liabilities – a summary of national positions:•Finland – Posiva / waste producers have responsibility until closure; thereafter it is
not clear, but some kind of transfer to the Government is expected•

Canada – not clear for HLW; NWMO has responsibility for repository operation &closure but ownership of waste is unclear as is any process after closure-7-

ITAC 11 Short Record•

Germany – ownership of the waste is transferred from the utilities to thegovernment for disposal and government has all subsequent liabilities•

USA/YMP – DoE will take liability for waste and, when land is transferred, also all
repository structures•

Sweden – utilities own waste but responsibility for repository with SKB and final
transfer of liability after closure unclear•

UK – ‘legacy’ waste from old nationalised industry is the responsibility of thegovernment; responsibility for operating the repository with the site licensing
company, but situation with future waste from private utilities not decided: aspecial fund may be established.

•

France – ownership & liability with waste producer for all time; land (for surface
installations) held by Andra.

•

USA/WIPP – all liabilities with DoE•

Switzerland – accepting the closure of the repository to their specifications
immediately transfers all liabilities from the implementer to the Federal
Government•

Japan – producer has responsibility to dispose of radwaste (including all costs);
implementer responsible for safety of disposal and liable for any damages; situation
after closure is still uncertain, it is presently a responsibility of the producer, but is
expected to involve some kind of transfer to the government at some point.

An interesting related point is the extent of land that has to be owned by the
implementer: is probably the minimum in the case of Switzerland and maximum for theUSA. An interesting case is SKB (maybe also Finland) – ownership not required, but isconsidered to simplify legal processes. In Japan, it seems that it will be necessary to
own the footprint – but this is not yet completely clarified.
Process of backfilling and sealing: a growing consensus in ITAC was that this is a very
important part of RC development which has been rather neglected in the past. Whenexamining different EBS designs, the sealing system should be included – potentially ina sequential manner that considers the stepwise process.
Concepts developed for sealing (seals as such, grouts, backfills, etc.) need to be
demonstrated – maybe first in generic URLs and then in a DIA URL. This needs fullscale tests of all system components under realistic conditions (first tests in laboratory,
but move underground as quickly as possible). A timescale of 30 years may be quite
short in this context, as such experiments may run for a very long time. Borehole seal
tests can also be important – and relate to the planning of the site characterisation
programme. Also site specific sealing concerns should be identified as early as possible(e.g. permafrost and glaciation in Scandinavia). Functions of seals have been studied insome programmes – may be balances between performance of buffer, backfill and seals;
can be very site / concept specific (and waste – NB special case of TRU).
A joint NUMO / JAEA project is looking at requirements for backfilling and sealing
related to disturbed zones; this appears to be a sensible experiment and good be a goodplace to utilise a requirements management system (SKB might be interested in-8-

ITAC 11 Short Record

collaboration; indeed this area might be a general focus for wider international
cooperation). No related experiments are currently planned, but may be possible in
Horonobe; may also be options abroad – e.g. the Canadian URL.
Seal designs tend to be rather simple and old; may be worth assessing potential
problems (e.g. bentonite/cement interactions and designing around these with a bit oflateral thinking. Requirements for the designs then need to be well specified (in terms ofboth performance levels and timescales).
Choice of seal involves showing•

Seal can be built•Long-term performance can be assured•

Role in total system performance can be adequately assessed to clearly define
requirements.

Open questions for the future are:•

Legal and administrative issues•

Technical issues•oSealingoMonitoringo

QA of waste emplacement (NB retrieval)oSafety assessment

Social issues (retrievability).

The requirement for credibility means that technology demonstration should allow
illustration of awareness of latest technology and its implication. A key question is“adequacy” – which may be very dependent on the site involved. There were
divergences in ITAC opinion, but many justifications for early consideration of this
aspect were provided. It was directly noted that, in some cases, difficulty of closure may
be a factor that distinguishes between sites and may be a relevant issue in site selection.
NUMO clarification emphasised the key, stepwise development of the general closure
plan (which is idealised, but site specific) and its relationship to concept development
and demonstration, monitoring, etc. under NUMO’s tight development timescale.
Discussion of retrieval / remediation associated with QA problems during emplacement
were noted still to be at an early conceptual stage and hence have not yet considered
practical constraints like reference emplacement rates.
Relationship of the work to the safety case was not made evident in this presentation,but even if this is implicit – it is valuable to emphasise such links to allow priorities tobe identified.
The RMS appears to be static; the example of operational monitoring is an example
where feedback is important to refine ideas – and could be a useful test case to checkthat the needed flexibility is built in.

-9-

ITAC 11 Short Recordc) Synthesis:
This session provided a good status overview of the position in leading programmes. It
was interesting to hear that considerations during RMS development led to
identification of this topic as a critical topic by NUMO. Topics that emerged as key
issues included:••

Concepts of Closure; there is some confusion and inconsistency in the terminologyof “closure” – here the NUMO terminology that emphasises the final closure blockis taken over.
o

The closure plan should be developed in step with the repository conceptoIntegrated assessment of safety requirements for all components are needed andshould guide designsoTo be integrated within the entire repository programme (leading from initialcharacterisation work and including any possible monitoring period between
end of emplacement operations and final closure)o

The stepwise implementation can be emphasised, in effect “operational”
sealing of emplacement tunnels and panels contribute to safety case supporting
the total closure conceptoShould be discussed and agreed with stakeholders (especially local public)

Technical feasibility of repository closure (backfilling and sealing) and theassociated closure strategy, including both engineering and demonstration of safety
Overall, this appears to be a rather neglected area worldwide (with some exceptions,e.g. salt), but is now being given higher priority. This offers potential forcollaboration in special large scale, long duration experiments in relevant
environments. There also needs to be development in safety assessment methodology
to allow backfilling and sealing requirements to be quantified (site- and conceptspecific).
For NUMO, it appears that it would be valuable to:Ö Initiate /continue backfilling and sealing studies related to closure; integratewith general repository concept development and associated safety assessment
to identify site- and concept-specific performance requirements. Possibly
include active involvement in large-scale, in-situ collaborative projects.
Ö Agree broad concepts (site, host rock and waste specific) and discuss withpotential volunteers
Ö Identify constraints on site characterisation and construction that the closure
concept may impose
Ö Prepare a defensible concept based on technology at the time of licensing
Ö Recognising that closure methods will evolve over future decades and license
conditions will need to be updated (NSA); this needs to be communicated toregulators to ensure that regulations are not overly rigid or prescriptive.

•

Monitoring- 10 -

ITAC 11 Short RecordoPre-closureThis is agreed to be essential in all programmes and should be planned in an integrated
manner, running from the start of site characterisation until closure. This includes
applications for safety and environmental impact (including guiding response toaccidents) and quality management during construction and operational, which need themethods and data handling to have assured quality. This may provide feedback tooptimise procedures and to guide corrective actions in the case of perturbations or nonconformity with specifications.
Performance confirmation is also important; here aims need to be clear and the risks ofthe monitoring process interfering with safety functions carefully assessed.
Development of remote sensing technology is now an area of interest in several national
programmes.
oPost-closure

The safety cases for deep geological disposal are based on passive safety barriers and do
not require monitoring following backfilling and sealing. There is less consensus onwhether it would be needed for other purposes and this is either undefined or notdirectly required by most regulators. Nevertheless, in some cases, it is envisaged by
implementers as a contribution to public acceptance. In such a case, it should be assured
that this does not impact safety. As this is far in the future, such monitoring should not
be specified in detail (or prescribed) to allow flexibility to respond to stakeholder
demands and technology at that time.
•

Retrievability (pre- / post-closure)

All agree that the capability to reverse emplacement of one (or a few) packages in thecase of operation problems is an essential component of the operational plan. Thisshould be illustrated and demonstrated.
There is less consensus on the need to show (or demonstrate) a capability to retrieve all
waste packages; this is often identified more as a response to public concerns (takenover into political decisions). In principle, waste is always retrievable – the differences
involve the costs and risks involved. Some programmes explicitly require demonstrationof retrieval before closure; there is less obvious requirement for ease of retrieval (ordemonstrated retrieval) post closure. It may be worth noting that ease of retrieval
probably gives a conflict with the requirement for closure, which should inherently
make access much more difficult.
•

Transfer of liabilities
The national examples show different cases;othe implementer is the government, who retains liabilityothe implementer / waste producer transfers liabilities to the government at thetime of closureothe implementer / waste producer retains liability (although this appears
actually to hide an eventual transfer to the government, which has not yet been
discussed explicitly)- 11 -

ITAC 11 Short Record

This is a political issue, but every implementer should be able to explain the position in
their country to interested stakeholders.
Block 5: Wrap up
For ITAC 12, the date was set provisionally as the week of 27th October 2008. It was
hoped that this could be combined with a visit to Rokkasho.
The format for future ITAC meetings should be reconsidered. Potential topics for future
meetings could include:¾ As report from ITAC members (or workshop):orepository construction and operation logistics (converting idealised designs toengineering reality)ocurrent hot topical areas in national programmes¾ Further report on the application of the NSA and RMS in siting and repository
concept development¾ S&T programme timescales and planningoLinking SI, PA and design; how these will be integrated as the siting processdevelopso

R&D activities in all relevant organisations

A programme should be established well in advance to allow any preparations requiredby ITAC members. For very technical NUMO presentations, it could be useful to havethese distributed electronically to ITAC in advance.

- 12 -

ITAC 11 Short Record

Appendix: Simplified summary of national closure concepts
CanadaFinlandFranceGermany

SwedenSwitzerland

UK

USA/YMP

USA/WIPP

Regulatory
guidance on
closure process

no

yes

yes

draft

yes

Yes- in newlaw andsectoral plan

Revisedregulations out
for consultationin early 2008

yes

yes

Pre-closure
monitoring

yes

yes

yes

yes

yes

Yes especially in
special pilot
facility

yes

yes

yes

Post-closure
monitoring

optional

optional

To be set by afuture law at
closure time

no

no

No

Likely to be
determined at
closureyes

yes

Pre-closure
demonstrated
retrieval

yes

yes

Yes, during
100 yearsnoyes

Not required but illustrated
by Nagra

open

no

Yes

Post-closure
demonstrated
retrievalnopossibly

To be set by afuture law at
closure timeno

Possibly

No

open

No

Yes

Definedliabilities postclosureUnclear(govt.)

Govt.?

Waste
producers

Govt.

Unclear(govt.)

Yes - federal
Gov.

Government?

Yes - DoE

Yes - DoE

Establishedsealingtechnology

noconcepts

concepts

yes

concepts

concepts

No

Yes

concepts- 13 -