IRID gathers knowledge from aroun
R&D of nuclear decommissioning
under an integrated management sy
Decommissioning of Fukushima Daiichi is unique, unprecedented and extremely difficult
gathering global knowledge considering the technological challenges.

Greeting
Ever since its establishment in August 2013, the International Research Institute for Nuclear Decommissioning (IRID) has been fully committed toan urgent challenge—research and development (R&D) of technologies required for the decommissioning work of the Fukushima Daiichi Nuclear
Power Station (NPS) including strengthening the foundation of decommissioning technology. In August 2014, the Nuclear Damage
Compensation and Decommissioning Facilitation Corporation (NDF) was reorganized from the Nuclear Damage Liability Facilitation Fund. Since
then, the division of roles among relevant organizations engaging in the decommissioning has been clarified: The NDF formulates strategies andR&D plans for the decommissioning; The Tokyo Electric Power Company (TEPCO) implements on-site operation; and IRID conducts R&D oftechnology required for the decommissioning. The four key players, including the government, have been working closely together in the effort todecommission the Fukushima Daiichi NPS.
As a result, the situation inside the primary containment vessel (PCV) and the reactor have been gradually ascertained through the developmentof technology for investigation inside the PCVs and indentification of fuel debris by cosmic rays. Meanwhile, the technological challenges to be
tackled have been also clearer.
Reflecting the revision of “Technical Strategic Plan 2017 for Decommissioning of the Fukushima Daiichi NPS of TEPCO Holdings, inc.” (Strategic
Plan 2017, hereinafter) by NDF, which provides the technological basis for the NDF Mid-and-Long-Term Roadmap for Decommissioning of the
Fukushima Daiichi NPS of TEPCO Holdings, inc. (Mid-and-Long-Term Roadmap, hereinafter) in September 2017, the Mid-and-Long-Term
Roadmap was revised by the government.
There it has been expressed that the fuel debris retrieval method would prioritize the retrieval of debris from the bottom of the PCVs focusing on“Partial submersion side access” method. The R&D for fuel debris retrieval is just about to enter a crucial phase.
To proceed with a safe and secure decommissioning of the Fukushima Daiichi NPS,IRID is committed to its responsibility of making steady achievements in R&D for thereconstruction of Fukushima, and gathering knowledge from all over the world. We
sincerely appreciate your kind guidance and continued support.
January 2018

International ResearchInstitute for Nuclear
Decommissioning
President

Hideo Ishibashi

C O N T E N T S◆IRID Organization Information ・・・・・・・・・・・・・・・・・・・・・・・・・ 02●

Organization Profile●

Organizational Structure◆Roles of IRID・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 04●

Activities of IRID●

Roles of the Organizations for the Decommissioning Projectof the Fukushima Daiichi NPS●

History : Chronology of IRID activities●

Overview of the Mid-and-Long-Term Roadmap●

IRID R&D Scope●

List of Government Subsidized R&D Projects Conducted by IRID

◆Scope of Work 1 : R&D for Nuclear Decommissioning ・・・・・・・・ 08
IRID R&D●

CLOSE UP Policy of Fuel Debris Retrieval and Current Approach

Overview of IRID R&D Projects
Major R&D Topics◆Scope of Work 2 : R&D with Overseas Organizations ・・・・・・・・・ 14●

CLOSE UP Enhancement of Cooperation with International Organizations◆Scope of Work 3 : Human Resources Development for R&D ・・・ 16●

CLOSE UP R&D in Collaboration with Universities (Achievements)●

Human Resources Development through Workshops with Universities

P R O G R E S S R E P O R T 2018

d the world forstem.
tasks in the world. IRID is promoting R & D by

Whataims forPurposeTo conduct testing and research for the decommissioning of nuclear
power stations, and implement projects aimed at improving thetechnological level of IRID member organizations and to put
technologies they develop into practical use.

Basic principles
We devote ourselves to research and development (R&D)
of technology for the current, most urgent challenge– the decommissioning of the Fukushima Daiichi Nuclear Power Station –from the standpoint of strengthening the foundation of nuclear decommissioning technology

Our Principles in Action

1

We work on R&D projects effectively and efficiently while advancing integrated project
management to develop and propose the best technologies and systems that are able tobe applied on site at the Fukushima Daiichi NPS at an early stage, in the face ofnumerous extremely difficult technological challenges

2

We build an optimal R&D structure through cooperation with relevant organizations aswell as IRID member organizations and gathering knowledge from Japan and abroad.

3

We actively promote efforts to develop and secure human resources who will comprisethe next generation of those working in nuclear decommissioning and related
technologies, including efforts to collaborate with universities and research institutions.

4

We strive to release information on our R&D activities and results to obtain theunderstanding of Japanese people, including those in Fukushima, and the international
community to relieve their anxieties.

5

We form an international research hub (center of excellence) through our R&D activities
and contribute to the acceleration of the decommissioning of the Fukushima Daiichi NPS
and improvement of technological capabilities in the international community01

IRID Organization Information
Organization Proﬁle
1. Name of the Organization

5. Memberships (18 organizations)International Research Institute for
Nuclear Decommissioning (IRID)<National research and development corporation>

Japan Atomic Energy Agency
National Institute of Advanced Industrial Science and Technology<Plant manufacturers, etc.>

2. The Head Office
5F, 3 Toyokaiji Building, 2-23-1 Nishi-Shimbashi,
Minato-ku, Tokyo 105-0003, Japan
TEL:+81 3 6435 8601

3. Date of Establishment
August 1, 2013

Based on the Research and Development
Partnership Act, the Ministry of Economy,
Trade and Industry has approved the establishment.

4. Scope of WorkR&D for nuclear decommissioning● Promotion of cooperation on nuclear decommissioning with
relevant international and domestic organizations● Human resource development for R&D

TOSHIBA ENERGY SYSTEMS & SOLUTIONS CORPORATION
Hitachi-GE Nuclear Energy, Ltd.
Mitsubishi Heavy Industries, Ltd.
ATOX Co., Ltd.

<Electric utilities, etc.>

Hokkaido Electric Power Co., Inc. Tohoku Electric Power Co., Inc.
Tokyo Electric Power Company (TEPCO) Holdings, Inc.
Chubu Electric Power Co., Inc. Hokuriku Electric Power Company
The Kansai Electric Power Co., Inc. The Chugoku Electric Power Co., Inc.
Shikoku Electric Power Company, Inc.
Kyushu Electric Power Co., Inc.
The Japan Atomic Power Company Electric Power Development Co., Ltd.
Japan Nuclear Fuel Limited

6. Board of Directors: Hideo Ishibashi
President
Vice president : Tamio AraiManaging Director : Tadashi Kawamura: Hirotsugu Fujiwara, Satoshi Ueda,
Directors
Hiroto Uozumi, Ei Kadokami, Masahiro Seto,
Koichi Noda, Jun Matsumoto, Goro Yanase: Atsushi Isobe
Auditor7. Number of Employees●

943 *(Excluding Directors)(As of October 1, 2017)* History of Establishment* Project Costs

The 1st report of Mid-and-Long-Term actions for the Fukushima
Daiichi Nuclear Power Station was created in July 2011,fourmonths later than March 2011 when the accident at Fukushima
Daiichi Nuclear Power Station occurred. At that time, opinions
that a dedicated national organization for the decommissioning
was necessary were issued from experts, then focused by the
Atomic Energy Commission.
In response to that situation, the establishment of a neworganization was speciﬁcally expressed at the Council for theDecommissioning of TEPCO’s Fukushima Daiichi NPS in March
2013. As a result of continuous study by establishing apreparation organization, a request for approval of theestablishment of IRID was submitted to the Ministry of Economy,
Trade and Industry in late July and approval was granted fromthe minister of the Ministry of Economy, Trade and Industry on
August 1. Then, the operation was started after the General
Meeting that is an autonomous legislative body of theorganization was held on August 8, 2013.

160(100 million yen )

148

143

120

120

80

46
40

FY2013(Aug -)02*Including those who are engaged in
the research of this organization
at member corporations.

FY 2014

FY 2015

FY 2016

P R O G R E S S R E P O R T 2018

Organizational Structure
General Meeting
Board of Directors

International advisors*Advisory panel tothe board of directors

Technology Advisory Committee*Advisory panel to IRID

R&D Strategy Planning Dept.

R&D Management Dept.

Planning & Management Group

Administration Dept.

Naraha Development Center

Accounting GroupInternational &Academia Cooperation Group

Corporate Communications GroupRadioactive Waste
Treatment and Disposal
Technology GroupPCV Investigation, Repair &Structural Integrity
Assessment Technology Group

Fuel Debris Retrieval
Technology Group

Reactor Interior andFuel Debris
Evaluation Technology Group（As of January, 2018)

Reference: What is the technology research association?
The technology research association is a mutual aid organization (Non-profit common benefit corporation) to process
joint research of technologies utilized in industrial activities for its own members. IRID selected “Technology research
association” to organize itself. The clarity and flexibility of organizational management are considered as merits inaddition to quick organizing.

Overview of the technology research association structure
R&D Tax system
Expense payment

Levy

Company(Member)

R&D Tax system
Expense payment

Levy

University, etc.
(Member)

The organization is changed to a corporation or a limited liability
company to apply the results of research.

Approval
Corporate entity
Technological Research
Association
Reduction entry

Public research
institute(Member)

Research results

Company(Member)●1.Organization change

A corporation or a limited liability company●2.Division and new establishment

A corporation or a limited liability company is newly established by divisionand the research result is commercialized in turn from that made available.

Established corporation or a limited liability company by division●3.Dissolution

The Technological research association is dissolved, and the member
organizations utilize the results of research.
TechnologicalResearch
Association●4.Division of technological research association

Identify specific research themes and divide the organization by research theme

Separately establishedTechnological research Association

Features of the Technological Research Association● Each member provides researchers, research funds, equipment, etc. to execute

jointresearch and the result is jointly managed and utilized by the members mutually.
● It is a joint research organization having a legal personality independent of its members.
● Transparency and reliability of organization operation are improved through theestablishment of approval requests and submissions to the competent minister, holding
general meetings of the members and board meetings, etc.

● Those who directly or indirectly utilize the result of joint research (corporate/individual,

including foreign company and foreigner) can be a member.
● This can be utilized as a stage for industry-academia-government collaboration because

universities, Research and Development Incorporated Administrative Agencies, technicaljunior colleges, local governments, foundations with research and development as themain purpose, etc. can join as members.
(Source) Excerpt from “What is the Technological Research Association?”
Homepage of the Ministry of Economy, Trade and Industry.

03

Roles of IRID
IRID works for R&D of decommissioning under a major goverment policy
while closely cooperating with organizations involved in
the decommissioning of the Fukushima Daiichi NPS. IRID has athree-pronged strategy; R&D of decommissioning, cooperation withdomestic and overseas organizations and human resource development.

01

Activities of IRID

R&D

IRID is an organization composed of 18 corporates thatare leading players for R&D of decommissioning the
Fukushima Daiichi NPS.
Although it aims toward cultivation/accumulation of thetechnologies necessary for the entire decommissioning inthis country, currently it is tackling R&D for thedecommissioning of the Fukushima Daiichi NPS as anurgent challenge based on the Mid-and-Long-Term
Roadmap of the government.
In addition, it is necessary to gather knowledge fromJapan and abroad to process the decommissioning of
the Fukushima Daiichi NPS, which is unprecedented in
the world and extremely difficult, therefore, IRID promotes
cooperation with related domestic and internationalorganizations. Moreover, IRID is promoting thedevelopment of human resources necessary to continue
the decommissioning work of the Fukushima Daiichi NPS.
A structure has been established in which threeorganizations cooperate closely together as one teamand where each role for decommissioning the Fukushima
Daiichi NPS is clarified: “Nuclear Damage Compensation
Facilitation Corporation (NDF)” formulates strategies and

HISTORY

2014〈August〉〈January〉

Institute for Nuclear Decommissioning (IRID)(Started with 17 corporates)
First president Hajimu Yamana〈September〉○Holding the 1st workshop on

development of human resources
contributing to R&D.

〈December〉○Holding the 1st “Technology Advisory
Committee.”○Holding the 1st “International Advisors
meeting”.

03
Human resource
development
For R&D of
decommissioning

R&D plans for decommissioning, “TEPCO Holdings”
performs on-site operations, and IRID conducts R&D.
IRID is committed to the decommissioning activities of
the Fukushima Daiichi NPS for its part in this structure throughits R&D.

〈May〉〈August〉○Nuclear Damage Compensation
Facilitation Corporation wasrestructured to Nuclear Damage
Compensation and Decommissioning
Facilitation Corporation (NDF).

〈March〉○Executing the investigation of unit 1
suppression chamber (S/C)
upper part by using investigation
apparatus.

○Executing demonstration tests ofsuction/blast decontamination
apparatus.

○With the joining of ATOX Co., Ltd.,the organization became an 18corporate structure as is current.

〈April〉〈July〉〈September〉○Executing actual machine
verification of low placedecontamination apparatus.
(Dry ice blast apparatus)○Holding the 1st IRID Symposium 2014
(in Tokyo)○Executing the investigation of the unit 2
S/C lower outer surface byusing investigation apparatus.

○Executing actual machine
verification of low placedecontamination apparatus(High pressure water
decontamination apparatus)

04

02
Cooperation withdomestic andoverseasorganizations
For decommissioning

Chronology of IRID activities

2013○Establishment of International Research

For nuclear
decommissioning○Executing investigation of the wall of
the unit 2 torus room by using asubmersible robot and a floor travelingrobot.

○Appointment of the 2nd president
Hirofumi Kenda〈November〉○Executing investigation of the spent fuelthat was transferred to the common
pool at Unit 4.
○Holding the 2nd “International Advisors meeting”.

P R O G R E S S R E P O R T 2018

Roles of the Organizations for the Decommissioning Project of the Fukushima Daiichi NPS.
Government

TEPCO Holdings( Fukushima Daiichi D&D Engineering Company )Progress management

Policy making and progress management

Steady implementation of decommissioning

Report● Formulate the Mid-and-Long-Term Roadmap, etc.

● Remove fuel from spent fuel pools

Mid-and-Long-Term Roadmap● Manage contaminated water● Store and manage rubble, waste, etc.
● Ensure safety/quality, improve work environments, etc.

ReportImplementation plan

ReportPresent key issues

Advice/Guidance
R&D Proposal
Practical applications ofdevelopment results
providing information

R&D needs

Implementation of R&D

Share progress
and issues

ReportReport/apply

Supervise/Review

Formulation of strategies andprovision of technological support● Develop a mid-and-long-term strategy● Progress management andIssue project grant

Nuclear Damage Compensation
and Decommissioning Facilitation
Corporation(NDF)

technical support for key issues● R&D for fuel removal from spent fuel pools● Carry out R&D planning and● R&D for preparation for fuel debris retrieval

progress management, etc.

● R&D for treatment and disposal of radioactive waste

Strategic plan

R&D results
Reportresults
Project cost
(Subsidy)

Nuclear Regulation Authority

Funds for R&D

Implementation of safety regulations■…General

2015

■…R&D

2016

〈February – May, May – September〉 〈March – July〉■…Human resources development■…International relationship2017〈February〉〈July〉○Observing unit 1 by using muontransmission method technology.

○Observing unit 2 by using muontransmission method technology.

○Executing investigation of inside theunit 2 PCV by using a scorpion robot.

○Executing investigation of inside theunit 3 PCV by using a submersible ROV.

〈April〉〈April〉〈March〉○Executing a full-scale test of
reinforcement technology for S/Csupport columns.

○Executing investigation of inside
unit 1 primary containment vessel(PCV)
by using a robot, PMORPH 1.

〈July〉○Holding the IRID Symposium 2015
(In Fukushima city)〈December〉○Developing an upper floor
decontamination apparatus.
○Holding the 3rd “International
Advisors meeting”.

○Completing a “Full-scale mock-up facility” in
the JAEA Naraha Remote Technology Center.

〈May〉○Executing actual machine verification of ahigh place decontamination apparatus (Dry ice
blast decontamination apparatus) on the 1st
floor of the unit 3 reactor building.

〈August〉○Holding the IRID Symposium 2016 (In Tokyo)○Executing investigation of
inside the unit 1 PCV by using PMORPH 2.

〈May – September〉○Observing unit 3 by using
muon tomography.

〈June〉○Executing a full-scale test by filling
water stoppage material in the S/C.

〈August〉○Holding the IRID Symposium 2017
(In Iwaki city)〈December〉○Holding the 5thInternational Advisors meeting○Appointment of the 3rd president Hideo Ishibashi〈November〉○Holding the 4th “International Advisors meeting05

Roles of IRID
Overview of the Mid-and-Long-Term Roadmap (Revised on September 26, 2017 )Decommissioning of the Fukushima Daiichi Nuclear Power Station is processed based on the “Mid-and-Long-Term
Roadmap for Decommissioning of the Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power
Company Holdings, Inc.” (Mid-and-Long-Term Roadmap) decided by the government.
The period until completion of the decommissioning work is divided into 3 phases: 1 st phase – 3rd phase and thecurrent period is the 2nd phase, “R&D to prepare for fuel debris retrieval.”
The current Mid-and-Long-Term Roadmap revised in September 2017 (4 th revision), in which the target processes(milestones) is described under the premise that it is subject to be revised depending on the on-site situation and
R&D results, aims for starting fuel debris retrieval at the initial unit during 2021.

Phases in the Mid-and-Long-Term Roadmap
December 2011
(Step 2* completed)

November 2013
(Starting fuel removal from unit 4)

Efforts to stabilize
conditions of the plant*Step 2Controlling radioactive
material release,achieving significant
reduction of radiation dose
● Accomplishment of cold
shutdown state●

December 2021

Phase 1

Phase 2Phase 3

Period up to thecommencement offuel removal from spent fuelpool of the initial unit

Period up to thecommencement offuel debris retrieval
from the initial unit

Period up to thecompletion of
decommissioning(Within 2 years)(Within 10 years)(30 – 40 years later)( ) represents the period from completing phase 2.

IRID has been engaged in various R&D activities under the
Mid-and-Long-Term Roadmap. As a result, IRID successfully
visualized inside the reactor by investigation inside the primarycontainment vessel using remote-operated robots andtomography utilizing a cosmic ray muon. On the other hand,
technological issues to be overcome are also clarified.
IRID continues challenging those issues and does its best for
the R&D required for the commencement of fuel debris retrieval
from the initial unit during 2021.

○Clarification of target processes (milestones)
For fuel debris retrieval
Decision on fuel debris retrieval policy (September, 2017)
Finalization of fuel debris retrieval methods for the initial Unit (FY2019)● Start of fuel debris retrieval at the initial Unit (within 2021)●●*Resource: Mid-and-Long-Term Roadmap (4th revision) on September 26, 2017

IRID R&D Scope
Decommissioning work●●●

Continuation of cold shutdown state of the reactor
Treatment of accumulated water(Countermeasure for contaminated water)
Reduction of radiation dose as a whole plant,
preventing spread of contamination
Fuel retrieval from spent fuel pool
● Fuel debris retrieval● Plan for storage/control and treatment/
disposal of solid wastes

Overview of R&D
Needs on-site

R&D isconducted by
IRID.

Decommissioning plans of
the nuclear reactor facility

R&D isconducted by
IRID.

TEPCO Holdings

Practical applicationof development

●

●

1F
Decommissioning

Applied research
Universities, etc.
Basic research
institutes

Basic research
Fundamental
researchJapan Atomic Energy Agency
Collaborative Laboratories for
Advanced Decommissioning Science

Development of common fundamental
technology, organization of fundamental facility,
acquisition of fundamental data

* The above chart was created based on the NDF Technology Strategy Plan 2017.

06

P R O G R E S S R E P O R T 2018

List of Government Subsidized R&D Projects Conducted by IRID
Subsidy Project of Decommissioning and Contaminated Water Managementin the FY2015, and the FY2016 Supplementary Budgets
Project name

Project Summary

PeriodMinistry of Economy, Trade and Industry
Agency for Natural Resources and Energy(As of end of November, 2017)*1

SupplementarybudgetProject Maximum
Cost *2(Subsidy Rate)

Development of Technology for
Investigation inside the PrimaryContainment Vessel(1)Formulation and upgrading of investigation plan and development plan(2)Development of equipment and systems to access and investigate specific areas(3)On-site demonstrations(4) Management of R&D

April 1,
2016- March 31,
2018

FY2015(Conducted in
FY2017)

4 billion JPY(Fixed)Development of Technology for Detailed Investigation
inside the Primary Containment Vessel(1)Formulation and upgrading of investigation plan and development plan(2)Development of equipment and systems to access,and investigation and element technology(3)Management of R&D

April 3,2017- March 31,
2018

FY2015(Conducted in
FY2017)

3.4 billion JPY(Fixed)Development of Technology for Investigation inside theReactor Pressure Vessel(1)Establishment and upgrading of the investigation/development plans(2)Conceptual design of corrosion control system(3)Development and selection of reactor core investigation method(4)Design and construction plan of integrated investigation system(5)Management of R&D

April 1,
2016- March 31
2018

FY2015(Conducted in
FY2017)

2 billion JPY(Less than 50%)Development of Fundamental Technologies for Retrieval of
Fuel Debris and Internal Structures (Development of small
size neutron detector)(1)Identification and its feasibility study of neutron detection
technology applicable to fuel debris retrieval, etc. at the
Fukushima Daiichi Nuclear Power Station.

April 24,2017- December 29,
2017

FY2016(Conducted in
FY2017)

2 billion JPY(Fixed)Upgrading for identifying comprehensive conditions inside
the reactor(1)Integrated analysis and evaluation of conditions inside the reactor(2)Estimation/evaluation of behavior and characteristics of fueldebris and fission products for integrated analysis and evaluation(3)Management of R&D

April 1,2017- March 31,
2018

FY2015(Conducted in
FY2017)

2 billion JPY(Fixed)Fuel Debris Characterization/Development ofAnalysis Technology(1)Estimation of properties of fuel debris in the reactor(2)Characterization using simulated debris(3)Development of element technology for fuel debris analysis

April 1,2017- March 31,
2019

FY2016(conducted in
FY2017-FY2018)

650 million JPY(Fixed)Development of Repair Technology forLeakage Sections in PCV(1)Consideration and planning of process leading to water replenishment in the PCV(2)Development of the PCV lower part repair technology(3)Development of the PCV upper part repair technology(4)Consideration of environmental improvement concept for
application of repair construction method in actual equipment(5)Management of R&D

April 1,
2016- March 31,
2018

FY2015(Conducted in
FY2017)

6 billion JPY(Less than 50%)

Full-scale Testing of Technology for
Repairing PCV Leakage Points(1)Full-scale tests of PCV lower part repair technology[1] Strengthening S/C support columns [2] Stopping water in vent pipes[3] Water stoppage by injecting filling in S/C(2)Confirmation of integrity of reinforcement materials andwater stoppage materials after testing(3)Maintenance of VR data for preliminary simulation tests(4)Management of R&D

April 1,
2016- March 31,
2018

FY2015(Conducted in
FY2017)

4 billion JPY(Fixed)Upgrading Approach and System for Retrieval of Fuel Debris
and Internal Structures(1)Technology development related to confinement function(2)Technology development related to collection and removal ofdust generated by fuel debris(3)Study of monitoring system for nuclide-accompanying fuel debris retrieval.
(4)Study of optimization, etc. related to securing safety ofworking method and system

April 3,2017- March 31,
2019

FY2016(conducted in
FY2017-FY2018)

2 billion JPY(Fixed)Development of Fundamental Technologies for Retrieval of
Fuel Debris and Internal Structures(1)Technology development related to preventing fuel debris diffusion(2)Element technology development related to the development of
retrieval equipment(3)Development of remote maintenance technology forfuel debris retrieval equipment(4)Development of monitoring technology at fuel debris retrieval, etc.

April 3,2017- March 31,
2019

FY2016(conducted in
FY2017-FY2018)

3.5 billion JPY(Fixed)Development of sampling technology for retrieval of fueldebris and internal structures(1)Study and formulation of fuel debris collection and sampling scenario(2)Design and trial production of sampling system and equipment forfuel debris in the reactor containment vessel(3)Conceptual study of sampling system for fuel debris in the reactor containment vessel

April 3,2017- March 31,
2018

FY2015(Conducted in
FY2017)

1.5 billion JPY(Fixed)Development of Technology for Collection, Transfer andStorage of Fuel Debris(1)Investigation and formulation of research plan for transfer and storage(2)Study of safety requirement specification and system related to transfer andstorage of fuel debris canister(3)Development of safety evaluation methods and verification of the safety(4)Study of fuel debris storage form, etc.

April 3,2017- March 31,
2018

FY2015(Conducted in
FY2017)

1.2 billion JPY(Less than 50%)Development and Management of Evaluation
Method of Seismic Performance/Impact of
RPV and PCV(1)Construction of safety scenario for possible large-scale earthquake(2)Development of seismic performance and impact evaluation method for safety scenario(3)Upgrading of safety scenario(4)Management of R&D

March 1,2017- March 31,
2018

FY2015(Conducted in
FY2017)

1 billion JPY(Fixed)Development of Technology for
Criticality Control in Fuel Debris Retrieval(1)Establishment of criticality evaluation methods(2)Development of technology for criticality control in fuel debris retrieval(3)Management of R&D

April 1,2017- March 31,
2018

FY2015(Conducted in
FY2017)

1 billion JPY(Less than 50%)

R&D for Treatment and Disposal of Solid Waste(1)Characterization(2)Study of management before treatment(3)Study of treatment concept and safety evaluation method that are suitable for solid waste(4)Integration of R&D results, etc.

April 1,2017- March 31,
2019

FY2016(conducted in
FY2017-FY2018)

2 billion JPY(Fixed)*1 Projects listed in IRID “Project Plan” *2 Project maximum cost and subsidy rates are cited from the value in the Solicitation Information.

07

Scope of work1

R&D for Nuclear Decommissioning

A key theme of R&D is fuel debris retrieval.
IRID is committed to promoting further
R&D based on the “Fuel Debris Retrieval Policy 2017.”
IRID R&D
IRID has been conducting R&D to proceed with the decommissioning of the Fukushima Daiichi Nuclear Power
Station (NPS), according to the Mid-and-Long-Term Roadmap. In order to improve decommissioning strategy, IRID
is studying alternative appropriate approaches and how to reduce risks, while exploring the end state (final form)
through tie-ups with TEPCO and relevant organizations.
Our three-key-R&D for the decommissioning are; “R&D for Fuel Removal from Spent Fuel Pool,” “R&D for
Preparation of Fuel Debris Retrieval” and “R&D for Treatment and Disposal of Solid Radioactive Waste.”

Overview of the Reactor Building and R&D Conducted by IRID

(Reference)

Fuel debris*1
Reactor building
Spent Fuel pool*2
Fuel debris retrieved from Three Mile Island Nuclear Power
Station Unit 2 (TMI-2) in the USA. (Photo provided by theJapan Atomic Energy Agency (JAEA))

Reactor Pressure Vessel*3（RPV）

R&D for Fuel Removalfrom Spent Fuel PoolR&D for Preparationof Fuel Debris Retrieval
Drywell (D/W)*5

R&D for Treatment andDisposal of Radioactive
Waste

Vent pipe*7
Suppression Chamber (S/C)*6
Torus room*8

Primary Containment Vessel (PCV)*4*1 Fuel debris: Lava-like fuel containing material that is produced underhigh temperatures through melting with control rods and structuresinside the RPV, after which it cools and re-solidiﬁes.

*2 Spent fuel pool: A water tank that stores spent fuel that is inserted intoa rack under water until decay heat generated from ﬁssion products
decreases. This tank is located on the top ﬂoor of the reactor building.

*5

Drywell (D/W): A safety structure, located inside of the PCV, that iscomprised of a ﬂask-shaped container that houses equipment,
including the RPV, and contains radioactive substances at the time ofan accident.

*6

Suppression chamber (S/C): Doughnut-shaped equipment that storeswater located in the basement of the reactor building. Condenses vapor
generated in the case of reactor piping breakage and prevents excesspressure from building up. It also serves the important function ofproviding a water source for the Emergency Core Cooling System(ECCS) in the case of a loss-of-coolant accident.

*7

Vent pipe: Connecting piping that takes vapor generated within theD/W to the S/C in case of a reactor pipe breakage. Eight vent pipes are
installed in the PCV of Units 1-3 at the Fukushima Daiichi NPS.

*8

Torus room: A room containing the torus-shaped (doughnut-shaped)
S/C located in the basement of the reactor building.

*3 Reactor Pressure Vessel (RPV): A cylindrical steel container thathouses fuel assemblies. This container can resist high-temperaturewater and high-pressure steam generated by the energy released by
nuclear ﬁssion inside. The RPV is housed within the PCV together withcooling equipment.

*4 Primary Containment Vessel (PCV): A steel container that houses theRPV, cooling equipment, and other devices that perform importantfunctions. This prevents radioactive substances from being released
into the outside environment under abnormal plant conditions, such as
when a reactor accident occurs, or in the event of a breakdown ofcooling equipment. It should be noted that each of the PCVs installed in
Units 1-3 at the Fukushima Daiichi NPS consists of a ﬂask-shaped
drywell, a doughnut-shaped suppression chamber and eight vent pipes
connecting the drywell and the suppression chamber.

08

P R O G R E S S R E P O R T 2018

CLOSE UP

Policy of Fuel Debris Retrieval and Current Approaches

Based on feasibility evaluation and proposals of fuel debris retrieval
methods that were studied in the NDF Strategy Plan, IRID is promoting
future activities in the following fuel debris retrieval policy.

1 Step-by-step approach

Fuel debris will be retrieved by starting with a small portion and then gradually expanding with a review of the work.

2 Optimization of whole decommissioning work

From preparation work through retrieval, transportation, treatment, storage and clearing up, a comprehensive plan is studied
aiming at a total optimization.

3 Combination of multiple methods

The study is executed assuming the side-access method for the bottom of the PCV andtop-access method for the inside of the RPV.

4 Focusing on partial submersion method*The full submersion method is also
considered by considering the advantage
of a shield effect.

Considering the difficulty of stopping water leakage and the exposure dose at work,
the partial submersion method is focused on because the full submersion method is difficult at present.

5 Proceeding forward with the side-access method,which is horizontal access to the bottom of the PCV

The fuel debris exists both at the bottom of the PCV and the inside of the RPV of each unit.The side-access method for the bottomof the PCV is prioritized to minimize the increase of risk accompanied with the retrieval in consideration of the following.
[1] Accessibility to the bottom of the PCV is the best and knowledge is accumulated, [2] There is a possibility to execute it earlier, and[3] It can be processed in parallel with spent fuel removal.

Current approaches based on the policy for fuel debris retrieval

Top access method – Image of debris retrieval –Continuous investigation of the inside PCV,
and acceleration of focused R&D

Side access method: Access rail method – Image of debris retrieval –● Debris “in” the pedestal ⇒ Insert the access rail from X-6

penetration into the pedestal and retrieve by using a robot arm.

Cover

●Debris “outside” of the pedestal ⇒ Retrieve by using a robot arm

through the equipment hatch.

Image of unit 2&3*
Shielding port with openable cover Dust scattering prevention film

Accessdevice in RPV(Image)

Up/Down

Opening

Access device
Rotating mechanism

Lower seal of thedevice

PCV
Pedestal opening for
CRD replacement
Cell adapter

Fuel debris

Robot arm
(For debris outside of thepedestal)

Cell forair tightness
X-6
penetration

RPV inner
surface seal
Machiningapparatus/
working arm

RPV

Cell for air
tightness

Manipulator

Equipment hatch

Access rail
Pedestal

Robot arm
(For debris in the pedest)

Fuel debris

Note) Those in the red frames are new equipment. *Position of X-6 penetration of unit 1 is different from those of unit 2&3.

*Scan the text or photos marked withby COCOAR2.

09

Scope of work

1

Overview of IRID R&D Projects

R&D for Nuclear Decommissioning

R&D for fuel debris retrieval including the developmentof investigation robots inside the reactor andretrieval technology are being promoted according to theMid-and-Long-Term Roadmap.
1 … R&D for Fuel Removal from the Spent Fuel Pool

3 … R&D for Treatment and Disposal of Radioactive Waste

2 … R&D for Fuel Debris Retrieval

for Fuel Removal from
1 ⓐ R&D
the Spent Fuel Pool
Evaluation of Long-term Integrity of Fuel Assembly●Work cart

Support cart

Basic Tests for Long-term Integrity

2

Technology for Investigation inside the Reactorⓒ Technology for Investigation inside the PCVDevelopment of investigation robots inside the PCV

Evaluation for feasibility of two methods(Conceptual image of investigation method)

Primary
Containment
Vessel（PCV)

Top hole drillinginvestigation method
Reactor building(R/B)
Steam drier

Steam separator
Reactor Pressure
Vessel（RPV)

Upper grid plate

Reactorcore

2

Relay cart

Transport cartⓑ Technology for Investigation inside the RPVSide hole drillinginvestigation
methodMuon detectorⓓⓓ Technology for Detection of Fuel Debris
Investigation technology
for fuel debris distribution
inside the RPV utilizing
cosmic ray muon.
An image of high density
substance thought to befuel debris is confirmedon the bottom of the RPV.
*The measurement atunit 2 was conducted by
TEPCO Holdings as a partof the IRID activities.

Shroud＊Size of one pixel: Equivalent to approx.
25 cm at the cross section of the nuclear reactor

26
24

Torus room

22
20
18
16

14

-6

-4

-2

0

2

4

North North Horizontal distance (m)6South South Structure of thebottom of RPV

Technology for Investigation and Analysis (Characterization) inside the Reactor

Identifying Conditions inside
the Reactor through Application ofCore
Severe Accident Analysis Code,
Moltencore
Data on the ActualCore support plate
Reactor, and Reactor
Particulate debrisInternals
Metal layer

Improvement of thephysical phenomenon
model

ShroudMolten pool
Solidified crust

Vessel Failure
Mechanism Model

PCV floor
Sump pit
Addition of debris inflow tosump pit and erosion model10○ Technology for

Remotely-operated
Decontamination in
the Reactor Building

Evaluation of Depositsof the Fuel Assembly Surface andFuel Integrity in Dry Storage

Height OP（ｍ）●

for Decontamination and2 Technology
Dose Reduction

RPV wall

Radiation HT Model
between Shroud and
RPV WallJet pump
Fuel support pieces
CR Guide tube
CRD Housing
Improvement of the model for Lower
Plenum Debris Bed Layering Model(Particulate debris inclusion to molten pool)
Modeling thermal conduction frommolten debris to CRD housing andradiation HT between CRD housing.
Improvement of the model for heat
conduction during debris – concrete
reaction at water injectionⓔ Fuel Debris Characterization

Characterization using simulated debris

ZrO2 cylinder

Ф25cm

High frequency
induction heating
coil

Simulatedfuel material, etc.
UO2＋ZrO2＋Zr＋Stainless steel

Air hole
Porousarea

50cm

Concrete test
body
Ф50cm

High-density
area
Layer containing
large amount ofmetals

Large MCCI test apparatus in cooperation with CEA and its test product generated in MCCI test

P R O G R E S S R E P O R T 2018

Technology for Treatment andDisposal of Solid Waste
90Sr activity concentration (Bq/g)

3

106

104

Rubble inlower part2

10

Rubble inupper part

100 10-1 10-2

103

105

107

Ratio of 90Sr/137Cs in rubble

D/W

SP

Groundwater

Shield plug

(Lid structure)

Technology for Collection,
Transfer and Storage ofFuel Debris

State of unit
canister storedⓐ

To water treatment facility

Corrosion inhibitor
removal device[Example of conceptual design of corrosion control system]

Operating floorⓑCorrosion
inhibitor supply
deviceSP

137Cs activity concentration (Bq/g)

Pressure filtering test
device to examine
dehydration treatment of
ALPS slurry

CST reactor
CST
injectionpump

Monitoring facility

Circulating
pump

RPV

10-3 10-4
101

Spent fuelpool

Before start offuel debris
retrievalDuring fuelCooler debris retrieval

SP

100

Full-scale absorber
vessel to be used forvarious absorption tests

Development of Corrosion Control Technology for RPV / PCV

Rubble in Unit 1 R/B
Sludge in Unit 1 T/B
Rubble in Unit 1 R/B*1
Rubble in Unit 2 R/B*1
Rubble in Unit 3 R/B*1
Sand in Unit 1 T/B*2

Saltwater tank

Absorbervesselⓖ Technology for Fuel Debris Retrieval

2

ReactorPressure Vessel
(RPV)

Mesh
(Side and bottom)(Unit canister)

Reactor building
Maintenance Carry out/in(Added)cell
DebrisRetrieval storage cell

(Buffering structure)

Idea of basic plan of storage canister
Building forcarrying out debris

Carry out cell

Storage canister
Handling cell

Storagefacility

Upper floor
Decontamination

Primary Containment
Vessel (PCV)

Decontaminationof high placesⓖ

Decontaminationof low placesⓒⓔ ⓖFuel debris
retrievalStorage incanister

Cleaning, etc.
of canister

Formulation of safety scenario for large earthquake
Development of seismic resistance /impact assessment method for formulating safety scenario● Safety scenario upgrading●●

Development of Technology for Criticality Control in Fuel Debris
Level 1

Suppression Chamber (S/C)

・Criticality approachⓕ・Restriction of debris

Specificmonitoring with theretrieval amount at a timemeasuresmonitoring system
・Application of Boric acid
(Primary ・Monitoring water level solution/non-soluble/ boric acid solution
absorbent
issues)concentration, etc.

ⓕ Technology for Repair and Water Stoppage of the PCV

Preparation for Full-scale
Mock-up Test

Level 2Control of abnormal operation andtermination of failures (MS system)

Monitoring of criticality approach to
Quick detection and control of criticality
prevent criticality
Prevention of
Parameter
Detection of
Mitigation ofabnormal operation
Monitoring
failures
impactTargetCriticality
control2

Carry out oftransport cask

Development of Seismic-resistance and Impact Assessment
Method for RPV / PCVPrevention of abnormal operation(PS system)

Vent pipe

Storage of canisterin transport cask

Workability verification test for reinforcement of S/C support columns

・Criticality detection ・Termination ofcriticality by injection
by neutronof boric acid solution
assemblies or FP
or non-soluble
gas concentration
absorbent

Technology for Retrievalof Fuel Debris andReactor Internals
DSP・Verification of workability of installation and collection of the placing hose with the device on the work floor・Verification of construction procedures through water flow and remote monitoring performance.

Well
Work floor

Work floor (The first floorof the reactor building is assumed.)

SFP lid

Scale model test facility

Appearance oftest device
Implementation ofreinforcing workability
verification test for
S/C support columns

Placing device
Simulated interference
objectives(two-stager grating)
Simulated suppression chamber
Simulated torus room

Placing hose

Robot arm

*Scan the text or photos marked withby COCOAR2.

11

Scope of work

1

Major R&D Topics

R&D for Nuclear Decommissioning

In 2017, IRID achieved R&D results ; investigation of theinside the reactor at unit 1, 2 and 3, muon measurement atunit 3, and full-scale mock-up test for repair technology.
R&D for fuel debris retrieval is also being processed.
Technology for Investigation inside the Primary Containment Vessel(PCV)
unit

1

unit

2

unit

3

■Unit 1 PCV inside
investigation robot(PMORPH 2)■Unit 2 PCV inside
investigation robot(Scorpion robot)■Unit 3 PCV inside
investigation robot(Mini-Sunfish)■Image ofinvestigation■Image of investigation■Image ofinvestigation
Penetration hole of PCV used forthe investigation (X-53 penetration)

Cable specification

・Composite cable including optical fiber

Rail for Control Rod Drive
mechanism (CRD) replacement

Measurement unit

Opening of the pedestal(Dosimeter + Underwater camera)・Approx. Φ20mm x Approx.40mm

Submerged ROV■[Purpose of the investigation][1]To confirm the distribution of the fuel debris on thebasement floor outside of the pedestal and reach
ranges of fuel debris to the PCV shell.
[2]To confirm the condition of the basement floor
outside the pedestal and the area near the opening
by using a self-operated investigation device tosuspend a dosimeter and a camera from the gratingof the 1st floor outside the pedestal.

■[Main achievements]
This was the first time to capture images of the conditionof the bottom of the PCV near the opening of thepedestal. The radiation dose increase was confirmed
while approaching the bottom of the PCV.

■[Purpose of the investigation]

Penetration hole of PCV(X-6 penetration)[1]To observe the basement floor of the pedestal wherefuel debris may exist.
[2]To obtain Design/Development feedback information(conditions of X-6, CRD rail, etc.) for the next
investigation inside the pedestal.

■[Purpose of the investigation][1]To obtain Design/Development feedback information(platform deformation, etc.) for the next investigation
for inside the pedestal.
[2]To confirm the condition of fuel debris that has fallen
into the platform in the pedestal and on the housingof the Control Rod Drive mechanism (CRD), andstructures inside the pedestal.

■[Main achievements]
This was the first time to capture images of the condition
inside the unit 3 pedestal. The images identified molten
solidifications and damages of multiple structures In thepedestal.

■[Main achievements]<Molten solidification wereconfirmed at bottom of thepedestal and structures inside
the pedestal.>

The grating in the pedestal was confirmed to have
dropped off and deformed in the grids. A large amountof deposits were also found. No significant damage wasfound on the CRD housing support near the pedestal
opening.

<Damage of multiple
structures and fallen
objects were confirmedin the pedestal.><Images near the lowest point>

Cosmic Ray Muon Tomography Inside the Reactor
The muon transmission measurement is one of the methods to obtain the information on distribution of material in
the RPV from transmittance of the Muon penetrating through the reactor. The muon transmission measurement was
conducted at Unit 3 from May to September, 2017. Information was obtained that there was no significant mass offuel debris in the original core portion, and that there is a possibility of a part of fuel debris remaining on the bottomof the RPV, although with uncertainty.
Reactor building
Rough positionof the core

South

Spent
fuel
pool
（SFP ）

Building wall (Main steam isolation
valve chamber)

Building wall (Main steam isolation valve chamber)

40

RPV

North

Spent fuel
pool

RPV

35
Core area
Concrete
outer wall of
PCV

Turbinebuilding

30

Spent fuelpoolCore area
Concrete
outer wall of
PCV

25
20

West

East
Measuring
deviceImage of measurement of the Muon
penetrating the reactor building(East – West cross sectional view)*Scan the text or photos marked with

12

Measuring device

South

North

15
10

Image of measurement of the Muon
penetrating the reactor building(South – North cross sectional view)

by COCOAR2.

(As of September 8, 2017)

Evaluation of mass distribution (Density length) by simulation(A case that fuel debris exists in the core area
and on the bottom of the reactor)

South
-20

North
-10

0

10

20

Evaluation of mass distribution (Density length)by Muon measurement

P R O G R E S S R E P O R T 2018

Repair Technology for Leakage Points Inside the Primary Containment Vessel■ A full-scale test at the JAEA Naraha Remote Technology Development Center[ 1 ] Technology for water stoppage in the Suppression Chamber (SC)A technology pursuing water
stoppage at pipe ends of thepassage (quencher, strainer)
between the inside and outsideof the S/C and at the damaged
portion of the S/C (φ50mm orless).

Image after
water stoppage[ 2 ] Technology for strengthening S/C support columns

Remotedeviceaccess route

Drilling S/CThis technology development is designed for seismic strengthening of the S/C
support columns, as the total weight of the S/C is expected to increase due tothe injection of filling materials for water stoppage.

Vacuum breakervalve*

Burying
strainer

Simulated quencher

Filling of
reinforcement
materials

Filling of
reinforcement
materials

Downcomer*
Buryingquencher

Test of work (during concrete placement)
Simulated strainer

Execution
procedure

S／C[1] Drill a hole in S/C[2] Place the material for water stoppage in S/C[3] Water stoppage at strainer andquencher by burying*Water stoppage at downcomer and vacuum
breaker valve by burying (Optional)

Test of work (Before placing strainer)

Candidatematerials

S／C[Candidate material] Underwater inseparable mortar

Underwater inseparable concrete

R&D for Fuel Debris retrieval
Specific R&D is being processed toward determination of the retrieval method for the initial unit (FY 2019) and starting the retrieval (during 2021).

Fundamental technology for the retrieval method is confirmed by an element test (smaller-scale model and full-scale model).
Cutting technology(Example)

Technologies for preventing spread of
the contamination and shielding (Example)□Core boring processing□Confirming work steps of the top access method

Access technology (Example)□RPV inner surface seal

□Reaction force support device

RPV

Lifting mechanism (Hanger)

Shroud support□Laser gouging processing
Optical system(Lens, etc.)

Water
Laser
Water

□Access device in RPV□Access rail in the pedestal□Flexible structure arm

Fuel debris
CRD Housing

Water
Scattered objects

MoltenportionMaterial

Method to access fuel debris at an early stage
Side-access method forfuel debris retrieval at thebottom of the PCV is being
studied by inserting anaccess device through apenetration hole of the
PCV on the 1st floor of thereactor building.

□Example of an access device (Robot arm)

CRD rail

PCV

Back and forth movement

Pedestal

PCV

Rotation axis

Pedestal
opening

Swing axis Tilt axis
Outside of PCV

Tilt axis
Telescopic

Pedestal side

Arm extended state

CRD rail
Inside of PCV*Scan the text or photos marked withby COCOAR2.

13

Scope of work2

R&D with Overseas Organizations

IRID enhances the relationships with international research
institutes and experts based on an “open structure”
management policy, and the transmission of
information including R&D achievements.

CLOSE UP

Enhancement of Cooperation with International Organizations

IRID accelerates R&D with overseas organizations andimplements the latest technology for the nuclear decommissioning.

Joint Research with
Overseas Research Institutions
Glass, Ooange color phase■ French Atomic Energy and Alternative

Concrete boundary layer

Before disassembly (Afterremoval of the upper cylinder)

Energies Commission (CEA)

Metal grain

Analysis of products of the molten core concreteinteraction (MCCI) was executed in 2017 by using
uranium the size of several tens kg with simulated
compositions of concrete and debris, as well asheating conditions for those of Fukushima Daiichi
NPS.

Conditions of the MCCI product
Metal layer on the bottom

After the majority of molten
substances are dug out.

Technical Cooperation with Overseas Nuclear Organizations■ Mississippi State University (U.S.A.)■ Argonne National Laboratory (ANL) (U.S.A.)

Dust including radioactive materials
will generate from fuel debris during
the retrieval. Therefore, it is necessary
to study ventilation systems to containthe generated dust within the PCV andreactor building. IRID visited theresearch facility in the U.S.A., in which
has related systems, and discussedwith engineers to reflect in the systemdesign.

ANL has experienced various
demonstration tests of molten
core concrete interaction(MCCI) in severe accidents with
the DOE (United States
Department of Energy).
Through technical discussions
with researchers that haveknowledge at the world’s top level, IRID obtained useful information
for future debris retrieval methods and processing technology.

International Advisors
The International Advisor committee consists of three nuclear experts fromabroad. This advisory committee was established with the purpose of advising
the IRID Board of Directors on organizational operation and management.
International Advisors provide advice on future challenges and required
improvements as well as leading discussions on international efforts andmanagement approaches.

■ Members * From left of the photo○Professor Melanie Brownridge (UK)
Head of Technology,
Nuclear Decommissioning Authority (NDA)

14○Mr. Luis E. Echavarri (Spain)
Former Director General of the OECD/NEA(experienced in the IAEA International Nuclear
Safety Group (INSAG))○Mr. Lake Barrett (USA)
Independent Consultant (former Site Director for the
Nuclear Regulatory Commission (NRC) for theThree Mile Island NPS accident)

P R O G R E S S R E P O R T 2018

Information transmission to the world
IRID has introduced the achievements of research and development at forums organized byinternational organizations.

The 7 th Vietnam - Japan Research /HRD Forum on Nuclear Technology (November 24, 2016)
Reporting current status of R&D for the decommissioning of the
Fukushima Daiichi NPS.

ICAPP2017 Plenary session “Fukushima Report" activity report(April 28, 2017)
Reporting "Overview of IRID R&D Projects“ as the current status of
IRID R&D.

The 34 th Japan – Korea Nuclear Experts Meeting(October 16, 2017)
Reporting the nuclear decommissioning titled “Status of IRID R&D
for fuel debris retrieval.”

MIT - Tokyo Tech Workshop on Innovative Nuclear Systems(October 27, 2017 )Reporting R&D for the nuclear decommissioning, specifically for development oftechnology for fuel debris retrieval and the investigation of inside the PCV, titled"R&D activities for Fukushima Daiichi Nuclear Power Station Decommissioning.“

R&D Activities with Overseas Organizations (List of major activities)○UK /Sellafield Ltd. : Handling, safe storage and criticality control of damaged fuel○France/Atomic Energy and Alternative Energies Commission (CEA) : MCCI test
○Hungary/Paks Nuclear Power Plant :Handling and safe storage of damaged fuel○Kazakhstan/

National Nuclear Research Center (NNC):
Debris characterization test

○U.S.A.

○Austria/IAEA : Technical information collection

・Pacific Northwest National Laboratory : Handling and safe storage of damaged fuel・Hanford Facility : Handling and safe storage of damaged fuel, study of ventilation system for debris dust・Idaho National Laboratory : Information collection of knowledge about TMI - II・Argonne National Laboratory : Exchange of debris characterization information
・Los Alamos National Laboratory : Development of debris detection technology
・University of California, Berkeley : R&D for treatment and disposal of solid waste
・Mississippi State University : Study of ventilation system for debris dust

15

Scope of work

3

Human Resources Development for R&D

Nuclear decommissioning is a long-term project that may last 30 to 40
years. It is therefore essential that we have young people engaging indecommissioning activities. IRID is committed to promoting
development of the next generation that will be involved in thedecommissioning.

CLOSE UP

R&D in Collaboration with Universities (Achievements)■Development of self-injection concrete for vent pipe water stoppage [ Ouchi Laboratory, Kochi University of technology ]For selecting a water stoppage material for vent pipe water stoppage, it is required to make both the ability to pass through a small diameter hose without
clogging (pumpability with small diameter hose) and the ability to be piled up even in a flowing water environment (water stoppage in flowing water environment)
simultaneously. A self-injection concrete was newly selected to satisfy the conditions in cooperation with Kochi University of Technology because the former
mortar-based materials and rubber-based materials don’t satisfy the requirements.
Remote-operated repair device

Ф50mm

Study of composition conditions(Ratio of concrete, type and amount ofadditives, etc.)[1] Verification test of water
stoppage capability

Performance verification test

[1] Basic property conﬁrmation

・Fluidity (Slump flow)
・Viscosity (V funnel flowing down time)・Grasping the range (selection)⇒Water stoppage confirmation test

Water stoppage
material[2] Pumpability test

[2] Pumpability test (15 cases)

・Passing through PVC (L-shaped pipe)・Blend selection(Fluidity, viscosity and retention time)[3] 1/10 model test

Inner diameter
42mm[3] 1/10 scale model test・Confirmation of filling and water stoppage

Decision of the best composition■ Operability improvement [ Yokokohji Laboratory, Kobe University ]Development of a control interface toconvey immediate self-motion* motor
commands to improve operability of thearticulated manipulator.

Examples of self-motion
movement of manipulator
with nine degrees of freedom* Movement to change the manipulator's
overall shape with the position of the hand
tip and the base ﬁxed

Fixing the position andposture of hand tip■ Development of Criticality Control Technology[ Misawa Laboratory, Kyoto University ]A nuclear characteristics verification test for neutron-absorbing material toprevent criticality and a feasibility verification test for critical approachmonitoring technology to detect a sign of the critical approach beforehand
were executed with Kyoto University Critical Assembly (KUCA).

Tests at KUCA

16

Changing posture(An image of shoulder moving back and forth)■ Development of remote collaboration
motion control system[Matsuhira Laboratory, Shibaura Institute of Technology]

With the purpose of saving operator manpower in a remotedecontamination system with plural crawler carts, a function toautonomously follow the leading cart
while adjusting the interval between
carts and avoiding obstacles wasdeveloped and a verification test applying
a control platform that can be used forcommon use in various robot systems
were executed in cooperation with the
Shibaura Institute of Technology.
Leading cart

P R O G R E S S R E P O R T 2018

Human Resources Development through Workshops with Universities
1. Workshops with
universities
IRID is promoting activities toenhance communication withyoung researchers and cooperatewith universities partly engaged innational decommissioning projects.
Small workshop with Tokyo Institute of Technology(January 20, 2017)

Workshop with the University of Tokyo (November 1, 2017)

2. PR activities at universities and research institutes, etc.
IRID is actively involved in the development of human resources by providing information through visits touniversities and research institutes.

Lecture at Fukushima Research Conference 2017
(September 5, 2017)

Lecture at National Institute of Technology,
Fukushima College (September 13, 2017)

Safety seminar of Light water reactor, Tohoku University(September 21, 2017)

3. IRID Symposium
The symposium of FY2017 (held in Iwaki) titled, “Challenges for Fuel Debris Retrieval,” with the purpose to contribute to
growing young researchers and engineers engaging in the decommissioning had more than 300 participants.
In addition, on the following day of the symposium, a site tour to the Fukushima Daiichi NPS and the JAEA Naraha
Remote Technology Development Center was conducted for students of universities, graduate students and students of
the National Institute of Technology who exhibited panels at the symposium.

Lecture session at the symposium

Explaining exhibited robots

Site tour with students

4. Participation in various events
IRID actively participates in lectures and events held by various organizations, including academic meetings.

Presentation at Atomic Energy Societyof Japan 2017 Fall Meeting(September, 2017)

Exhibition at Environmental Radioactivity
Measures & Radioactive Waste Disposal
International Exhibition - RADIEX2017(October, 2017)

Exhibition at Robot Festa Fukushima 2017 (November, 2017)17

International Research Institute for
Nuclear Decommissioning

5F, 3 Toyokaiji Building, 2-23-1 Nishi-Shimbashi,
Minato-ku, Tokyo 105-0003, Japan
TEL:+81 3 6435 8601
http://irid.or.jp/en/

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