Relationship between the subsidized projects of Decommissioning and ContaminatedWater Management program and connection to preliminary engineering
Mitsubishi Research Institute, Inc.
(Management Office for the Project of Decommissioning and Contaminated Water Management) 1
Masaaki Matsumoto1, Naoki Kondo1, Keishun Nakamura1 , Erika Ogawa1

１．Introduction
To safely and steadily carry out the decommissioning of the Fukushima Daiichi NPP, it is important to gather together
wisdom in Japan and overseas, and conduct research and development. For this reason, the Ministry of Economy, Tradeand Industry has implemented a Subsidy Program of "Decommissioning and Contaminated Water Management" to support
research and development with high technical difficulty since FY2013. In fiscal 2017, 16 subsidized projects wereimplemented by subsidized operating entities. The contents of research and development in these projects were diverse.
To apply the results obtained in the subsidy projects to the decommissioning of Fukushima Daiichi NPP, mutualcoordination among subsidized projects are essential.

２．Relationship between the subsidized projects of Decommissioning and Contaminated
Water Management program and connection to preliminary engineering
The whole diagram of the project for Decommissioning and Contaminated Water Management implemented in FY2017
is shown below. The Decommissioning and Contaminated Water Management projects are roughly divided into “InternalInvestigation”, “Debris Retrieval (development of method)”, “Debris Retrieval (development of fundamental technologies),“Improvement of Work Environment” at fuel debris retrieval, and “Processing of solid waste”. The figure shows the statusof collaboration of results obtained in each project.
Application in actual equipment · Preliminary engineering（implemented by TEPCO Holdings, out of scope of Decommissioning and · Contaminated Water Management project）✓ Results of development technologies for safely processing
and disposing solid waste generated by accident.
✓ Investigation results of the waste stream✓ Estimated information and data such as distribution,amount, and composition of fuel debris“Internal Investigation”○Development of Technologies
for In-depth Investigation ofPCV Inside
Grasp the situation inside the PCV with highaccuracy, increase the scale of access andsurvey equipment, and upgrade the survey
technology to finalize the method of fueldebris retrieval.

○Development of Investigation
Technology of Inside of PCV
Formulate investigation plan and developplan, develop essential technologies, develop
equipment to access the interior of the PCV
from a small opening, on-site demonstration,
construct a larger access route, to determine
the fuel debris retrieval policy and to finalize
the method.

○Development of Investigation
Technology of Inside of RPVDevelop remote investigation equipment andsystem for accurately grasping the situation
inside and outside the pedestal inside the RPV,to determine the fuel debris retrieval policy.

○Development of Technologies
for Grasping and Analyzing
Properties of Fuel Debris(Estimation of Aging Propertiesof Fuel Debris)
Acquire knowledge on the fine particles inthe shape of fuel debris, their migration intowater, and predict the long-term aging
behavior of fuel debris.

○Development of Technologies
for Grasping and Analyzing
Properties of Fuel Debris
Update fuel debris characteristics list,
characterization such as behavior during
dehydration using simulated debris, develop
analysis technology, consideration oftransportation method to facility for analysis,
etc.

“Processing of Solid Waste”✓ Results of examination ofretrieving and collecting fuel debris○Research and Development ofProcessing and Disposal of Solid Waste✓ Fuel debris characteristics list
Milestones in the Mid-andLong-Term Roadmap(1) Finalization of fuel debris
retrieval methods for the initial
Unit (FY 2019)(2) Start of fuel debris retrieval
at the initial Unit (within 2021)✓ Analysis andinvestigation needs✓ Information and dataon estimated fueldebris distribution,amount, andcomposition etc.
✓ List of Fuel debris
characteristics✓ Information anddata such as therequired hardnessof fuel debris
related to thedevelopment of theretrieval equipment✓ Results ofapplicability fromthe survey
improving theperformance sensor✓ Analysis andinvestigation needs✓ Technology toaccess inside andoutside the pedestaland detect neutrons
derived from thefuel debris○Upgrading Level of Grasping
State inside Reactor
Based on the results obtained by FY 2016,
estimate the conditions inside RPV and PCV
will be promoted through analysis andevaluations which should mitigate theuncertainty in the estimations of conditions
inside RPV and PCV.

“Debris Retrieval(Development Method)”○Advancement of Retrieval Method andSystem of Fuel Debris and InternalStructures
Conduct technology development necessary for solving
problems to ensure safety of retrieval method andsystem; comparative evaluation from the viewpoint ofexposure and maintainability, to complete the conceptual
study of retrieval method and system.

○Development of Criticality Control
Technologies of Fuel Debris
Prevention of criticality for each fuel debris retrieval
procedure and criticality control method that does notaffect radiation exposure and the environment even if it
occurs should be formulated, to determine the fuel debris
retrieval policy.

✓ Data based on element
tests for feasibility ofretrieval method

Milestones in the Mid-and-Long-Term Roadmap
Technical prospects regarding policies for treatmentand disposal and its safety (around 2021)

After characterization of the solid waste, investigate andexamine to present the study of treatment concept andsafety evaluation method, and develop necessary technology
to reduce the risk of storage and management of solid waste.

✓ Study results ofretrieving andcollecting fuel debris✓ Criticality control
information on water
stoppage point andmethod✓ Knowle
dge ofsortingwaste✓ Safety scenario✓ Safety requirement,
specification and system
related to transfer andstorage of fuel debris
canister and study results offuel debris storage form

✓ Criticality controlmethods✓ Safety requirement✓ Functional requirement“Debris Retrieval (Development ofFundamental Technology) ”○Development of Fundamental Technologies for
Retrieval of Fuel Debris and Internal Structures
Perform element tests according to the policy of fuel debris retrieval
and development of full-scale for actual machine to contribute on theselection of the method of retrieval of fuel debris and internalstructures.

○Development of Fundamental Technologies for
Retrieval of Fuel Debris and InternalStructures(Development of Small Neutron
Detectors)
Develop a small size detector that can measure weak neutrons underhigh gamma ray dose, to identify the fuel debris distribution inside thePCV.

✓ Safety scenario✓ Results of applying
sampling of fuel debris
for sensor performance
improvement✓ Physical properties datafor design of samplingsystem and retrieval
equipment✓ Safety requirement,
specification andsystem related totransfer and storage offuel debris canister andstudy results of fueldebris storage form
✓ Study results ofretrieving andcollecting fuel debris✓ Information and data on estimated fuel debris distribution, amount,composition, and behavior during drying of fuel debris✓ List of Fuel debris characteristics✓ Safety requirement, specification and system related totransfer and storage of fuel debris canister, study results offuel debris storage form

✓ Results for the confirmationof the applicability of repair/ water stoppage technology
in actual equipment✓ Developed System on thetechnology for collection,transfer and storage✓ Safety requirement, specificationand system related to transfer andstorage of fuel debris canister andstudy of fuel debris storage form

“Debris Retrieval (Improvement ofWork Environment)”○Development and Management ofEvaluation Method of Seismic
Performance/Impact of RPV and PCVIdentify the impact on critical devices inside the RPV /PCV at the occurrence of a large-scale earthquake and s
to consider measures to prevent or reduce the effects toconfirm the effectiveness of a safety scenario based onsuch measures.

○Development of Repair Technology
for Leakage Sections in PCV
Establish the containment function within the PCV,develop repair technology for the leakage section andconfirm actual application, from the standpoints ofradioactive material release/dispersion prevention, andcooling maintenance, to determine the fuel debris
retrieval policy and to finalize the fuel debris retrieval
method.

○Full-scale Test of Repair Technologyfor Leakage Sections in PCV
Perform a full-scale test of the technology developed in"Development of repair technology for leakage section incontainment vessel" and confirm its viability.

○Development of Sampling
Technologies for Retrieving Fuel Debris
and Internal Structures
Based on the research results of FY2008 and the latest
knowledge of Fukushima Daiichi, review the sampling
plan and further study the technical issues related to thesampling system and equipment.

○Development of Technologies for
Containing, Transportation and Storageof Fuel Debris
Canister storage specifications mainly from the safety
design set by FY 2018 will be evaluated and improve fromthe standpoint of removal method and transfer of fueldebris and new canister storage specifications will be set.

"Subsidy for Decommissioning and Contaminated Water Management project cost" Subsidized project by Ministry of Economy, Trade and Industry
The Management Office for the Project of Decommissioning and Contaminated Water Management (Mitsubishi Research Institute, Inc.)* This figure does not exhaustively show the cooperation among each project, but items which seemed to beimportant are extracted and summarized by MRI in the light of the project objective.
* Cooperation between subsidized projects included in each R&D of "Internal Investigation", "Debris Retrieval(Development Method)", "Debris Retrieval (Development of Fundamental Technology)" and "Debris Retrieval(Improvement of Work Environment)" is appropriately implemented.

Copyright (C) Mitsubishi Research Institute, Inc.

【Reference】[1] Ministry of Economy, Trade and Industry, Agency for Natural Resources and Energy, Progress of R & D Project and Direction of Next Plan, Decommissioning andContaminated Water Management Team Meeting / Project Management Office Meeting (51st)[2] Decommissioning and Contaminated Water Management Ministerial Conference “Mid-and-Long-Term Roadmap towards the Decommissioning of Fukushima Daiichi
Nuclear Power Station of Tokyo Electric Power Company Holdings, Incorporated” , August 26 th, 2017[3] International Research Institute for Nuclear Decommissioning, Annual Research Report 2017[4] International Research Institute for Nuclear Decommissioning Website, R&D results (http://irid.or.jp/research/20170000/)[5] Management Office for the Project of Decommissioning and Contaminated Water Management Website (http://dccc-program.jp/, http://en.dccc-program.jp/)

1４．Website
Japanese：http://dccc-program.jp/
English：http://en.dccc-program.jp/

Top page

Information on Solicitation Process

５．Project List
Internal Investigation

Improvement of Work Environment

Debris Retrieval

Copyright (C) Mitsubishi Research Institute, Inc.

Processing of Solid Waste

2