Geological Disposal Through Global Collaboration
Nuclear Waste Management Organization of Japan＝Geological Disposal

November 2016

NUMOʼs mission
The safe and reliable disposal of radioactive waste produced by nuclear power generation isa challenge that all countries operating nuclear power plants must address. In Japan,
the organization responsible for meeting this challenge is NUMO (Nuclear Waste Management
Organization of Japan), which was established in October 2000 based on the “Speciﬁed Radioactive
Waste Final Disposal Act” (the “Final Disposal Act”).

Basic Policies
Top priority will be given to safety during all activities.
We aim to co-exist with the local community.
We aim to become the socially trustworthy organization.
Based on the above basic policies, we will strive to achieve our mission throughthe following six action guidelines.

NUMO performs a vital role in the safe geological disposal of high-level radioactive
waste (HLW) produced from the reprocessing of spent fuel and also TRU waste＊.
As the organization responsible for this task in Japan, NUMO moves steadily
forward with its program of implementing the geological disposal
project openly and responsibly, at the same time striving to coordinate itsactivities with interested regional and local communities.

Action Guidelines
1. Work continuously to improve technology to ensure safety＊TRU waste： Low-level radioactive waste (LLW) containing more than a specified concentration of long-lived radionuclides,generated by the operation and dismantling of reprocessing plants and MOX fuel fabrication plants.

2. Actively participate in domestic and international activities to enhance
our technology for geological disposal
3. Take into account and incorporate public opinions throughout NUMOʼs activities
4. Think and act as a member of the local community in order to contribute to its
sustainable development
5. Be proactive in providing information on our activities in a comprehensible manner

The Realization of the Geological Disposal ofRadioactive Waste

6. Ensure compliance with relevant legislation and rules, and act with integrity andprofessionalism, whilst seeking to be cost eﬀective

In carrying out our mission, we give top priority to ensure safety above all.
It is indispensable for us to act carefully at every measure following principles toensure safety.
Because we will use large area to construct the facility, it is essential that we livearound the area as a member of the local community and contribute to its
sustainable development.
To promote our business, we need to be regarded as a socially trustworthy organization.
Based on the above recognised points, we set the following basic policies.

NUMOʼs initiatives
In moving ahead with the repository site selection process, the understanding andacceptance of residents in the regions concerned is important. In addition to grassroots
activities such as forums and symposiums aimed at disseminating an understanding of
the importance and safety of the geological disposal project, NUMO has also been engaging
in public relations activities using a wide range of up-to-date communication tools.
For regions that have shown an interest in the geological disposal project, NUMO has
also been endeavoring to provide information, including explaining detailsof the project to stakeholders individually.
Since it was established, NUMO has also been involved in promoting various
technological developments aimed at improving the reliability of geological disposal.
Against this background, NUMO prepared a Safety Case report. Preparations are in place
to allow NUMO to begin site investigation and selection at any time.

＝Collaboration

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Radioactive waste for geological disposal anddisposal strategy
Types of radioactive waste for disposal by NUMO

Waste disposal method

NUMO is responsible for the geological disposal of vitriﬁed high-level radioactive waste fromthe reprocessing of spent fuel used in the nuclear power plants, as well as TRU waste containing
more than a speciﬁed concentration of long-lived radionuclides, which is generated by theoperation and dismantling of reprocessing plants and MOX fuel fabrication plants.

Although radioactivity decays spontaneously with time, HLW and TRU remain radioactive for very
long time periods and therefore it is necessary to isolate the waste from the human environment
for this time. Diﬀerent methods for disposing of the waste have been investigated by international
institutions and countries worldwide, and the international consensus is that geological disposal
in a stable host rock deep underground is the most safe and reliable method.
In Japan, it has been decided that the waste will be disposed of in stable host rock formation
more than 300 meters underground. A multi-barrier system consisting of engineered and natural(geological) barriers will isolate and contain the radioactive waste over the long timescales.

HLW

TRU waste

Engineered barriers for HLW

Example of TRU waste

Vitriﬁed waste

Emission ﬁlter

Hulls(example of hulls and ends)

Disposal tunnel

Hulls and ends

(spent silver absorbent)

Engineered barriers for TRU waste

Vitriﬁed
waste

BackﬁllEnds

Overpack

Concentrated liquid waste(steel container)(above a speciﬁed radioactivity level)

Miscellaneous solid waste

Fuel assembly(above a speciﬁed radioactivity level)

Thickness:〜 20 cm
Host rockPackaging

Stainless steel canister

Invert＊After reducing waste volumes by compacting solid waste andconcentrating liquid waste, the waste will be placed in theprescribed containers. In some cases the waste will be
immobilized using a solidiﬁcation agent. In this way, the waste will
be processed into waste packages that are suitable for disposal.

Height: 〜 1.3 m
Diameter: 〜 40 cm
Weight: 〜 500 kg

Canister

Examples of waste packages:（Speciﬁcations of Japan Nuclear Fuel Ltd.）

Volume of vitriﬁed HLW to be produced
・Stored and managed in Japan:
2,300 canisters (as of the end of March 2016)

CanisterContent:
Hulls and ends

・If spent fuel that has already been produced is reprocessed:〜 25,000 canisters (as of the end of March 2016)
・Total amount expected to be produced in the future:〜 40,000 canisters

Drum

Rectangular container

Content:
Content:
Emission ﬁlters,
Miscellaneous solid waste
miscellaneous solidwaste, concentrated liquid waste(solidiﬁed after treatment byevaporative concentration, etc.)

Volume of TRU waste to be produced〜 18,100 m is anticipated3

Host rockBuﬀer material(compacted clay)

3

Thickness:〜 70 cm

FillerWaste package＊The invert is the base of the tunnel and is composed ofconcrete or a similar material.

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Visual impression of a repository
The underground facilities will comprise tunnels for transporting and emplacing the waste
packages and will be constructed in a stable host rock formation more than 300 meters underground.
On the surface, the facilities required for supporting underground excavation and operation andclosure of the repository will be constructed.

Construction of the disposal tunnels, emplacement of the waste packages and backﬁlling of
the disposal tunnels will be carried out underground. The underground facilities for a HLW
repository are extensive and the various operations will be carried out in parallel in separate
areas (disposal panels).

Example of repository layout
Example of co-located geological disposal facilities for HLW and TRU waste.

Surface facilities

In the surface facilities, the vitriﬁed HLW will be encapsulated in overpacks and the TRU waste
will be packaged; the necessary inspections of the packages will also be conducted. These tasks
will be carried out via remote operation in an area where radiation shielding is in place.

Inclined
shaft

Ramp

The facilities will also be designed against events such as earthquakes or ﬁres and accidents
where waste packages may fall or be overturned.

Shaft

Shaft

Shaft

Undergroundfacilities(TRU waste disposal area)

Disposal panel(compartment where disposal
tunnels are constructed together)

Undergroundfacilities

Connectingtunnel

Over 300 mdeep(HLW disposal area)

Scale of facilitiesSurface facilities: 1-2 km2
Underground facilities： HLW disposal area: around 3 km by 2 km
TRU waste disposal area: around 0.5 km by 0.3 km＊1＊2＊1 HLW disposal area
＊2 TRU waste disposal area

56The repository site selection process
Newly added process

The geological disposal program
The selection of a repository site will be undertaken via a three-stage process based on the “Final
Disposal Act” and involves the selection of Preliminary Investigation Areas (PIAs), the selectionof Detailed Investigation Areas (DIAs) and the selection of a repository construction site.
In 2002, NUMO initiated open solicitation of municipalities nationwide, seeking areas to carry out aliterature survey as the ﬁrst step in selecting a ﬁnal disposal site, however no survey has yet been
carried out. Considering this situation, the Japanese government decided to carry out nationwide
scientiﬁc screening in order to identity municipalities which could be suitable for a literature survey,
if accepted.
The site selection procedure speciﬁed in the Final Disposal Act consists of three steps, namely
literature survey, preliminary investigation and detailed investigation.
NUMO will compile reports on the investigation results at each stage of the process and will holdexplanatory meetings. The opinions of local people expressed at these meetings will be madeknown to the relevant prefectures and municipalities together with NUMOʼs views and selection
will proceed on the basis of respecting local opinions, obtaining stakeholder agreement andsecuring the government approval.
The government has stipulated that, when approving each stage of the site selection process,the opinions of the municipality mayors and the governors of the prefectures concerned must belistened to and respected. Selections that oppose these views will not take place.
Following the selection of a repository construction site, the disposal facilities will be designed
and a safety evaluation will be undertaken; construction will only begin after a safety review
by government experts.

Nationwide scientiﬁc screening
by Government (Mapping)Open solicitation
tolocal municipalities

Implementation of dialogue activities(meeting etc.)
・Proposals by the national
goverment to municipalities
・Application by municipalities

Literature survey
Checks of previous earthquake activity, volcanic eruptions, fault activity, upliftand erosion and other relevant tectonic phenomena will be made using
records of past activity, written references and other documents in order todetermine the suitability of applicant areas and the surrounding regions.

1

Selection of Preliminary Investigation Areas (PIAs)
based on literature surveys

It will be conﬁrmed from past records that there are no indications ofsigniﬁcant geological perturbations resulting from natural phenomena suchas earthquakes and that there is no risk of such phenomena occurring inthe future.

Preliminary investigations
Studies will be made – from the ground surface – of geological formations,rock properties, geological structures, groundwater characteristics,
geochemical characteristics and geodynamics using geophysical, borehole
and trench investigations.

Preliminary investigations

２ Selection of Detailed Investigation Areas (DIAs)
It will be conﬁrmed that the host formations where geological disposal
may be implemented and the formations in the vicinity are stable, that
there are no obstacles to tunnel excavation and that there is no risk thatgroundwater ﬂow and other relevant phenomena will have a negative
impact on the underground facilities.

Detailed investigations
In parallel with more detailed investigations from the ground surface,underground research facilities will be constructed and various investigations
and experiments carried out.

Detailed investigations

３ Selection of a repository construction site

It will be conﬁrmed that the physical and chemical characteristics of thegeological formations where geological disposal will be implemented aresuitable for constructing a repository.

Construction
Operation
Closure / environmental monitoring

7

Repository construction

8NUMO proﬁleCorporate history

Basic framework of the geological disposal project

NUMO was established in October 2000 based on the Final Disposal Act, as an “authorizedimplementing entity” approved by the Minister of Economy, Trade and Industry (METI).

NUMO shares its waste management duties with the government, the power companies andother responsible organizations and is moving forward with its activities in close collaboration
with these entities. The government supervises and regulates the work undertaken by NUMO
and designates and monitors the organization responsible for administering and managingthe waste disposal funding.

In December 2002, NUMO launched an open solicitation of municipalities nationwide in a search
for areas to carry out feasibility studies on sites for repository construction. Information
packages supporting this open solicitation were sent to 3,236＊ municipalities.
In June 2007, the Final Disposal Act was amended and some TRU waste was also included
for geological disposal; this waste type was therefore added to NUMOʼs sphere of operations.
＊As a result of mergers, there are currently 1,718 municipalities (as of September, 2016).

Description of projects

Based on relevant legislation, the power companies and other entities make ﬁnancial
contributions to NUMO according to the electrical output of the nuclear power plants. Theseﬁnancial contributions are administered and managed by the Radioactive Waste Management
Funding and Research Center, as designated by the Minister of Economy, Trade and Industry.

International collaboration

The projects undertaken by NUMO include:

In the interests of moving the disposal project forward smoothly, NUMO has entered into
collaborative agreements with overseas implementing organizations responsible for radioactive
waste disposal, based on the principles of mutual beneﬁt and reciprocity. It undertakes
information exchanges and joint research with these organizations in areas such as disposal
technology, safety assessment, site selection and public relations activities. The organizations
with which NUMO has collaborative agreements (or memoranda) are: Posiva (Finland),Nagra (Switzerland), SKB (Sweden), DOE (USA), ANDRA (France), NDA (UK) , KORAD (Republic ofKorea) and the Taiwan Power Company (Taiwan).

・Selection of PIAs, DIAs and the repository site・Construction and operation of the repository
・Repository closure
・Collection of fund・Other supporting operations

Organization

Board ofDirectors
Auditors

CorporatePlanning
Department
Corporate Planning
Corporate Governance● Information Disclosure

President
Vice-President
Senior Executive Director
Executive Directors

GeneralAﬀairs
Department
General Affairs
Finance & Procurement● Waste Disposal FundManagement

Address:
Board ofCouncilors

Communication andPublic Acceptance
Department
Public Relations
Media Support● Regional communication

Mita NN Building, 2nd Floor, 1-23 Shiba 4-chome, Minato-ku, Tokyo 108-0014
Telephone: +81-3-6371-4003 (Communication and Public acceptance Department)
Fax: +81-3-6371-4101
Website: http://www.numo.or.jp/en/

Science andTechnology
Department
Technical Planning
Repository Engineering● Performance Assessment● Site Investigation
Technology● Site Characterization

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●As of July 1, 2016

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