FY2017 Annual Repor t

Published in December 2018
Central Research Institute of Electric Power Industry
1-6-1 Otemachi, Chiyoda-ku, Tokyo 100-8126 JAPAN
Tel: +81-3-3201-6601

FY2017 Annual Report

Fax: +81-3-3212-0080

E-mail: www-rdd-ml@criepi.denken.or.jp
URL: https://criepi.denken.or.jp/en/index.html

CRIEPI

Contents

Overview of the FY2017 Annual Report・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 2
Ⅰ.

Business Report１.

Outline of Business Activities・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 4２.

Research Report
2–1.

Customer Services
17-Utilization of an AI Technique for a Maximum Demand Alert Service・ ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・48

Environment
18-Evaluation of the Biological Effects of the Magnetic Field Generated
by Induction Heating (IH) Cookers・ ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・50
19-Development of a General-Purpose 3D Numerical Model for Thermal Discharge Diffusion
and Cooling Water Intake・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・52

Outline of Results・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・6

Utility Management

List of Research Subjects・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・14

2–2.

20-Quantitative Analysis of the Role of Nuclear Power in Energy Policy in Japan・・・・・・・・・・・・・・・・・・・・54

Major Research Results

Common in the Multiple Fields

Nuclear Power Generation

21-Development of a Tool Analyzing the Operational Characteristics of Smart Communities・・・・・・56

1-Development of an Evaluation Technique for Slope Failure in the Periphery of
Nuclear Power Plants with Application to Actual Site・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・16

22-Development of an Evaluation Technology to Achieve Long-Life Lithium-ion Batteries・・・・・・・・・・・58

2-Improved Reliability of Safety Evaluations for Reactivity Initiated Accidents (RIA) ・・・・・・・・・・・・・・・・・・・18
3-Development of Flaw Detection Technology with High Accuracy for Dissimilar Metal Welds・・・・・20
4-Verification of dose Rate Effect based on the Mechanism of Cell Competition・・・・・・・・・・・・・・・・・・・・・・22
5-Development of a Method to Detect Helium Leaks from Canisters Inside Concrete Casks・・・・・・・・24
6-Improvement of the Vitrification Process in Spent Fuel Reprocessing Plants・・・・・・・・・・・・・・・・・・・・・・・・26

Thermal Power Generation
7-Proposal of a Method for Planning the Timing of Chemical Cleaning based on
Monitoring of Creep Damage Status・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・28
8-Development of a Carbonized Woody Biomass Fuel Capable of High Co-firing Rate in
Coal Fired Thermal Power Plant・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・30

Hydropower Generation
9-Development of a Technique for Assessing the Risk of Public Damage Imposedby Hydropower Facilities・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・32

Renewable Energy
10-Development of Hybrid Power Generation Technology Utilizing Geothermal
Energy and Biomass・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・34

Ⅱ.

Financial Statement
１.

Overview of Financial Statement・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・60

２.

Financial Statement・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・62

Facts & Figures
Research Results / Intellectual Property・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・66
Research Network・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・67
Organization・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・68

Electric Power Transmission and Distribution
11-Development of an Accurate Demand and Supply Simulation Model with
the Aim of Future Balancing and Frequency Control・ ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・36
12-Development of Image Processing Technology and an AI Technique to Support
the Maintenance of Transmission Towers・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・38
13-Development of a Technology to Remotely Measure the Salt Density of
Insulator Surfaces using a Laser・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・40
14-Establishment of a Test Method for Evaluating the Immunity of Drones inElectromagnetic Environments・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・42
15-Elucidation of the Cable Surf-Riding Phenomenon of Underground Power Cables・・・・・・・・・・・・・・・・44
16-Establishment of a Security Testbed Targeting Power Grid Control Systems andSubstation Automation Systems・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・46

Keyword Index・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・70

Overview of the FY2017 Annual Report

Overview of the FY2017 Annual ReportElectric power companies have recently started to apply risk information to autonomous andsuccessive improvement of the safety in nuclear power generation. They are expected to provide
stable power supply service economically even under the current situation that large-scale natural
disasters occur frequently and electric power demand is saturating. In addition, customers even ask
for new and interesting values to the electricity in accordance with the diversiﬁcation of theirpreferences and life styles.
CRIEPI engages in research and development activities with consideration to these circumstancesand has produced the following results. In the nuclear power generation ﬁeld, we have produced
several results contributing to the improvement of safety against low-frequency events as one of thepieces of Probabilistic Risk Assessment. We have also produced results supporting supply/demand
coordination at higher level in accordance with increasing dispersed power generation andprogressing digital technology, as well as oﬀering new customer services aimed at the promotion ofelectriﬁcation. Moreover, we have developed technologies utilizing AI, etc. which contribute toreasonable maintenance and management of aging electric power facilities.
On the other hand, we believe that energy system reforms is inevitable to sustain safe and economical
supply and usage of electric power, in response to the international trend towards accelerating
decarbonization. To lead the way in such reforms, we have clariﬁed the technological challenges andformulated mid-to-long term research strategy towards ﬁnding solutions to such issues.
Our mission to support electric power industry as the leading research institute through technology
development remains unchanged under the ever- changing environment surrounding the electric
power industry. Considering future changes in the society and technology, we continuously
contribute to the electric power industry and to the society by creating and oﬀering reliable values
grounded in scientiﬁc objectivity through the integrated knowledge and eﬀorts of our researchers invarious expertise.
Masahiro Kakumu

CRIEPI, as the“central research institute of the electric power industry”and“academic research institute contributing to society through scientiﬁctechnology research”, will support reform of technologies and systems relating
to the supply and usage of energy, including electric power, and continue toguide the energy industry forward.

President

2

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report3

Ⅰ. Business Report1.

Outline of Business Activities

1. Outline of Business Activities
CRIEPI produced various research results helping to solve the issues faced by the electric
power industry and society. Moreover, in order to lead reforms in the supply and usage of power
and other energies, we have formulated research strategy from a mid-to-long term perspective.

■ Strengthening and developing fundamental research ability
・As of the end of FY2017, CRIEPI employed a total of 739

broad range of ﬁelds ranging from electricity, civil
total, 393 personnel have obtained their doctorates.

・CRIEPI injected resources with priority to R&D aimed at solving common issues faced by the electric power industry and,based on PDCA through good communication with clients, etc. promoted steady research and produced results. In concreteterms, we have developed a behavior evaluation method for masses of rock when slope failure occurs in the periphery of a
nuclear power plant, wood biomass fuel capable of a high co-ﬁring rate in coal-ﬁred power generation and AI-based
technology to determine the deterioration of transmission towers. We also developed a tool to analyze the interaction
between energy resource usage on the customer side and electric power quality in smart communities.
Furthermore, after identifying events predicted to manifest in the future, we engaged in research to oﬀer solutions to theassociated issues and new values, producing results in the various areas of the electric power business such as the buildingof a security veriﬁcation environment for network control systems and the development of an all-solid-state battery withexcellent safety.

See Fig. 1, p.16 to p.59 [2-2. Major Research Results] (22 in total)

・CRIEPI responded to research requests in accordance with accidents, trouble and other issues at electric power companies
by customizing our cultivated knowledge, technologies and research results to suit the circumstances of the individual
worksite and swiftly oﬀering suitable solutions for such situations.

See Fig. 2・CRIEPI proactively engaged in consigned research projects from the Japanese government, etc. and challenged ourselves by
undertaking leading research addressing various issues that could improve the research and research abilities helping tosolve issues faced by the electric power industry. Such research themes included advancement of the method for evaluating

Research support&
management89

administration personnel. Research personnel specialize in aengineering and construction to socioeconomics. Of the 739■ Contributing to the electric power industry and society throughproducing/providing results

Administration86

people comprising of 653 research personnel and 86

See Fig. 3
・C R I E P I e n g a g e d i n t h e p r o f e s s i o n a l d e v e l o p m e n t o f
researchers who possess both high-level expertise and a deep
understanding of the electric power industry through theElectricity
102

Civil engineering&
construction
118

Socioeconomics
39
Information &communications
36

promotion of new, challenging research and element
technology research, long-term dispatch to electric powercompanies, etc.
・CRIEPI carefully selected large research facilities essential to

Mechanical87

Environment 53

Nuclear engineering 50
Fig. 3solving issues faced by the electric power industry, then

Biology
35

Chemistry
44

Personnel conﬁguration by subject ﬁeld as ofend of FY2017

made the necessary installations and updates. Such facilities include a thermal power supply water treatment tester
used in the development of a substitute agent for hydrazine, the anticorrosive agent used in high-pressure boilers of
power plants, as well as a radiation sensitivity analysis facility used to elucidate the mechanism of dose rate eﬀects
aimed at higher rationalization of radiation protection criteria.

See p.13 [Major New Research Facilities]

・Continuing our relationship with institutions both in Japan and abroad possessing high technological standards, CRIEPI
actively promoted researcher exchanges, information exchanges relating to R&D, etc. Particularly in regards to EDF(France), we dispatched researchers involved in customer communication networks and engaged in the development of
new fundamental technologies combining our respective technologies. Meanwhile, CRIEPI accepted EDF researchers
involved in seismic motion studies and strengthened our collaboration even further. We also actively promoted joint
research with EPRI (U.S.A.) in the ﬁeld of nuclear power generation.

See p.67 [Research Networks]

the impact of irradiation on nuclear reactor pressure vessels and core internals, as well as the development of CO 2
recovery-type next-generation IGCC technology.
Utility management 1.4 %Common in the multiple ﬁelds 8
Utility management 4

Nuclearpower
generation

Environment 7

Customer Services 6

10.3%
Customer Services

32

Electric power※ Renewable energy
transmission
was promoted in theand distribution
7 research themes ofother related ﬁelds

29

Thermalpower
generation

21

Renewable energy※ 1

Environment

Hydropower
generation 1

Fig. 1 No. of research themes by ﬁeld for FY2017

5.5%

Common in the multiple
ﬁelds, other 4.1%
Nuclear power
generation

11.6%

Thermal power
generation 13.7 %Electric power transmission
and distribution

Hydropower
generation

47.3%

6.2%

Fig. 2 Consigned research projects from electric powercompanies for FY2017 (percentage of cases by ﬁeld)■ Initiatives for formulating research strategy to lead reforms■ Contributed to an electric power industry and society that utilizes ourintellectual property and proprietary knowledge/technologies

・CRIEPI broadly disclosed its research results to the general public through research reports and academic papers so thatsuch results could beneﬁt the electric power industry and society at large. We also utilized our patents and software invarious ways, including contributing to the enhanced safety of nuclear power generation through providing electric
power companies with TONBOS, software for evaluating the speed of tornado missiles.
See p.66 [Research Results / Intellectual Property]
・CRIEPI attended various government and academic committees to contribute to the formulation of standards and public
policies relating to electric power and other energy forms such as amendment to the international standard“Guidelines
for the Application of Insulation Coordination”by the IEC aimed at achieving rational insulation design of electric
power grids.
・Upon request from electric power companies and manufacturers, CRIEPI performed short-circuit tests on power
equipment such as circuit breakers, etc. at our High Power Testing Laboratory. We also fulﬁlled our responsibility as a
PD Examination Center under the PD (Performance Demonstration) certiﬁcation program which involves performing
ultrasonic ﬂaw detection on nuclear power generation equipment.

・In order to lead reforms in the supply and utilization of electric power and other energy forms, based on the three higher
perspectives listed below, CRIEPI has clariﬁed the issues we need to tackle by unleashing our total capabilities not only in
relation to each business area of the electric power industry, but also transcending conventional business frameworks, andformulated mid-to-long term research strategy. We will appropriately reﬂect this research strategy in our future research plans.

■ Proactive dissemination of research activities and results

・CRIEPI hosted research report brieﬁngs and symposiums, as well as published PR materials including CRIEPI TOPICS topresent society with our research activities and results through disseminating information via various forms of media.

Overall optimization of energy production, distribution and utilization
Assuming the expansion of renewable energy, this initiative aims
at the overall optimization of not only production, distribution
and utilization of electric power, but also gas and thermal energy
forms in order to simultaneously establish decarbonization,
economic and stable supply, etc.
Digital transformation

Risk base technology system

In order to support digital transformation (social andbusiness changes through digital technology) in theelectric power industry, CRIEPI is proposing new values
by utilizing not only IoT and AI, but also advanced digitaltechnology such as cloud robotics.

Using probabilistic methods, etc. to quantitatively andhierarchically appraise the increase/decrease of therisks individual technological choices could have onenergy systems to guide eﬃcient investments overall.

Higher perspectives for energy system reforms

4

Central Research Institute of Electric Power Industry

FY2017 Annual Report■ Steady promotion of research base development and rationalization,
sophistication and cost reduction of operational tasks

・CRIEPI continued to promote research base development aimed at strengthening our research ability and reducing ﬁxed
management overheads through activities such as the practical completion of a base in Yokosuka Area by theconstruction of a material analysis building and transfer of the research function from Komae Area, as well as ﬁnalizing
the concept for a new building that will serve as a hub of researcher activities, etc. in the Abiko Area.
・While maintaining our personnel scale at the reduced level of 750 members, in preparation for the establishment andstrengthening of organizational management able to ﬂexibly respond to changes in the management environment,
CRIEPI pushed ahead with the construction of a new fundamental task system and task outsourcing. We also continued
eﬀorts for cost reductions in both research and operational aspects through the ongoing promotion of competitive
quotations in our procurement activities, etc.

Central Research Institute of Electric Power Industry

FY2017 Annual Report52. Research Report

Looking ahead to changes in the environment surrounding the electric power industry, CRIEPI
engaged in various research projects for the creation of new values relating to achieving
improvement of electric power facility safety, rational maintenance and operation, as well as
the supply and utilization of energy. We have produced concrete results through such eﬀorts.

Safe and stable operation of light water reactors
Improvement of maintenance techniques for light water
reactors

Research was promoted for the nine areas ranging from nuclear power generation to common in the multiple ﬁelds.

Yield Stressconsidering initial yield stress of the steels to explore more

Please refer to p.14 for a list of research subjects.

Yield stress is the minimum
stress that materials to bepermanently deformed.

ﬁgures on the right).

Below is an outline of the research results for each area. Also, from page 16 onwards, we have provided detailed
descriptions of the major research results worthy of special mention.

Thermal Aging
embrittlement
A reduction of toughness
over time due tomicrostructural evolution
which is caused byexposure to hightemperature environment.

Nuclear Power Generation
Advancements of the safety of light water reactors

A technique to surmise
subterranean structure bymeasuring the time a seismic
wave takes to travel from anearthquake epicenter to theobservation point using a
combination of various
earthquake epicenters andobservation points.

Rupturing
The phenomena whereby
multiple faults aredestroyed simultaneously
during an earthquake.

elucidated the transport characteristics at the interface between thesimulating stem cells at low dose rate.
See p.22

Eruption Column Simulation
Recreate a scene where
high-temperature liquid billows
upwards together with the nearby
air while spreading to thesurrounding area

In contrast to individual
technical skills such as
specialist knowledge andskills, non-technical skills aret h o s e s u c h a s
communication andteamwork mainly engaged
in within an organization.

180

20

60

100

140

180

180

140

100
60

20

Measured embrittlement (℃)

for storing spent fuel in Japan, we developed a method based on temperature change to detect leaks of helium
from the canister due to stress corrosion cracking.

Bentonite

・For the timely implementation of marine monitoring of radioactive substances according to the emergency plancomplied by the government in the case of nuclear power plant accidents, we performed marine diﬀusion
simulation of eight ocean regions related to 18 Japanese nuclear power plants. From the results have beenobtained the knowledge to identify those areas to be monitored in each ocean region.

・With the aim of establishing ﬁre and ﬂooding protection measures in nuclear power
plants, we have developed ﬁre and ﬂooding PRA implementation procedures for theJapanese plants using U.S. evaluation guides as references, compiling Japanese guides.

Promotion and advancement of independent public safety activities
・For the sake of improving our response ability during emergency situations in nuclear
power plants, we prepared a Team Resource Management (TRM) Skill Training Guide(right) that includes non-technical skills, and applied this to drills for the personnel ofClay formed by theweathering of tuﬀ, etc.
Bentonite swells when it
absorbs water, making itdiﬃcult for water topenetrate.

Medium Depth
DisposalEstablishment of probabilistic risk assessment (PRA) technology

FY2017 Annual Report140

See p.24

・In order to support safe operation of spent fuel reprocessing plants, we clariﬁed the formation mechanism of

Evaluation of impact of major accidents

Central Research Institute of Electric Power Industry

100

・With the aim of establishing a monitoring technique in preparation for the introduction of the concrete casks used

See p.18

emergency response headquarters in power plants.

60

Measured embrittlement (℃)

Establishment of nuclear fuel cycle technology

reactor to rise suddenly, as well as the relationship with pressure.

Non-technical Skills

20

Neutron irradiation embrittlement prediction
results(a) Initial yield stress was not considered(b) Initial yield stress was considered

See p.16

the conditions causing the temperature around the fuel inside a nuclear

20

-20

behavior at the time of slope failure and developed a method to evaluate

simulated thermal‐hydraulic behavior during an accident and elucidated

60

-20

failure caused by earthquakes, CRIEPI used 3D analysis to reproduce rockinitiated accidents (RIA), we performed an experiment whereby we

100

（b）

・In order to improve the safety of nuclear power plants in relation to slope

the impact force due to falling rock with higher accuracy.

140

-20

See p.20

Low

atmosphere and eruption column.

・In order to improve the reliability of safety evaluations for reactivity

PRA is a systematic
method to analyze various
accident scenarios which
could occur in engineering
facilities such as nuclear
power plants, as
exhaustively as possible toquantify the frequencies
and impacts of the
scenarios. The risk values
expressed in the productof the frequencies andimpacts evaluated by PRA
demonstrate how safe thefacilities are.

measurement procedure.

1：1

-20

To improve crack sizing in DMWs, we developed a newHigh

the eruption column, which determines ash fall characteristics (right), andAdvancement of core damage assessment methodology

Probabilistic Risk
Assessment (PRA)

for dissimilar metal welds (DMW) performance demonstration.

stem cells can be excluded from normal tissues by experiments

Temperature

eruptions, CRIEPI used simulation to recreate the development process ofof cast austenitic stainless steels in Japanese BWRs.

Forging

Plate
Weld
±22℃

180

・CRIEPI succeeded in introducing internal cracks in mockups

carcinogenesis at low dose rate, CRIEPI clariﬁed that damaged

rupturing of active faults in zones where the seismic velocity changes rapidly using on-site investigations targeting
・In order to predict the impact of ash fall damage caused by large-scale

proposed guidelines to evaluate thermal aging embrittlement

・I n o r d e r t o e l u c i d a t e t h e m e c h a n i s m s o f r a d i a t i o n

・In relation to securing safety in nuclear power facilities during earthquakes, CRIEPI elucidated the factors that stop
past earthquakes and seismic wave tomography analysis.

・According to Atomic Energy Society of Japan standard, CRIEPI

Maintenance and expansion of radiation protection
systems

Establishment of evaluation techniques for low-frequency phenomena
Seismic Wave
Tomography Analysis

precise evaluation of neutron embrittlement of RPV steels (the（a）

Predicted embrittlement (℃)

・Neutron irradiation embrittlement prediction method forreactor pressure vessel (RPV) steels was modiﬁed by

6

Outline of Results

Outline of Results

Predicted embrittlement (℃)

2–1.

2–1.

The TRM skill andtraining guideprepared by CRIEPIThis method of disposal
targets the low-level
radioactive waste withrelatively high radioactivity
and involves burying thewaste deep down in theearth with ample leeway
for general subterranean
utilization. There is arequirement to secure adepth of 70 meters ormore for at least the next
100,000 years even whenground erosion is taken
into consideration.

water-soluble crystalline material called as“yellow phase (YP)”and needle-like crystals containing platinum groupelements, which are the major causes of problems during vitriﬁcation of highly-radioactive liquid waste.
See p.26

Support for radioactive waste disposal operations
・In order to appropriately evaluate the safety of radioactive waste disposal into the future, CRIEPI developed ananalysis code able to handle the complicated phenomena consisting of thermal, hydraulic and mechanicalprocesses in the near ﬁeld of disposal facilities and improved reliability by conducting comparisons of analysis
results with ﬁve other participating institutions in joint international research program.
・In order to support safe operation of spent fuel reprocessing plants, we clariﬁed the formation mechanism ofwater-soluble crystalline material called as“yellow phase (YP)”and needle-like crystals containing platinum groupelements, which are the major causes of problems during vitriﬁcation of highly-radioactive liquid waste.
・In order to support applications for medium-depth disposal of radioactive waste complying with new regulatory
requirements, CRIEPI conducted a dose assessment sensitivity analysis targeting medium-depth disposal facilities
and newly presented a method displaying safety indicators based on probability theory by individual items relating
to facility design and installation.

Central Research Institute of Electric Power Industry

FY2017 Annual Report

7

2–1.

Outline of Results
Response to large-scale introduction of renewable energy

Thermal Power Generation

・In order to respond to load ﬂuctuation accompanying the increase of renewable energy connected to theGas Turbine
Combined Cycle(GTCC)

Ensuring reliability of existing thermal power plants
・In order to reduce maintenance costs of water wall tubes used in thermal power plant boilers, CRIEPI proposed amethod to determine the optimal timing to perform chemical cleaning of the scale adhered on the inner surface oftubes to maximize tube life and clariﬁed that it was possible to reduce the cleaning frequency.
・In order to help countermeasure ash adhesion

A method of generating
power by pulverizing coal
into a powder form,
combusting this in a boiler
and driving turbines using
the generated steam.

to develop a technology that clearly observes furnace

See p.28

Hydropower Generation

structures in pulverized coal combustion ﬁeld (right).

Disaster prevention and maintenance and management
for hydropower facilities

・As a measure to prevent the corrosion of plantboilers used in coal ﬁred thermal production, CRIEPI
improved“CRIEPI Coat”, a coating technology togroove corrosion.
・CRIEPI conducted the chemical analyses and creep

Original image

damage or destruction of hydropower facilities such as intake

Clear visualization of furnace structures using an opticalﬁlter and image processing

chambers in the event of natural disasters, CRIEPI developed aprogram to analyze water and debris penetration requiring only

tests for welded joints of high chromium steel pipes,
which exhibit excellent material strength at high temperatures, in order to improve the diagnosis accuracy of creep
damage for safety operation of thermal power plants. As a result, we clariﬁed that the variation of creep strength isdominated by the composition ratio of the base metal of the material.
・In order to help establish countermeasures for biofouling in the cooling water systems of thermal power plants,

simple settings.
ColumnA cylindrical-shaped
container or equipmentused in experiments.

water after heavy rain, we ran water resembling subterraneanwater through a column ﬁlled with sand and succeeded in

CT (right).

carry-out, we collected the arsenic, selenium, etc. present in eluent by using chelating agent and established a・With the aim of establishing a method to evaluate the values oftechnique for the quantitative analysis using X-Ray Fluorescent in a short period of time.

hydropower plants from multiple aspects (hydropower premium),
CRIEPI investigated various forerunner utilization value

・In order to further improve the thermal eﬃciency of coal gasiﬁcation
combined cycle system, which helps to mitigate environmental load,
CRIEPI performed an experiment using a bench-scale gasiﬁer and anumerical analysis technique (right) and veriﬁed that gasiﬁcationeﬃciency could be improved by adding steam into the gasiﬁer.
・In order to reduce CO2 emissions in coal ﬁred thermal power generation,
CRIEPI developed carbonized woody biomass fuel capable of highco-ﬁring rate without the need for major modiﬁcations to conventional
power plant equipment.

assessments and extracted case studies of assessments indicating

Portion where
gasiﬁcation
reaction
occursRenewable Energy

Gasiﬁcation
reaction rate
High

140

Silica dust No.2 (2 - 3 mm)

120
100
80
60

Silica dust No.2 (2-3 mm) +Silica dust No.7 (100 - 200 μm)

40
20
0

0 10 20 30 40 50 60 70 10 20 30 40 50 60 70

X［mm］

Comparison of gasiﬁcation reaction rates
when steam is not added (left)
and when it is added (right)

Diversiﬁcation of fossil fuels
・With the aim of reducing fuel cost due to fuel type expansion in thermal power generation, CRIEPI evaluated the
combustion characteristics when high-fuel ratio bituminous coal (fuel ratio 2.5 ‒ 4), which has not been used todate, is blended with the current bituminous coal and clariﬁed that both NOx conversion ratio and uncombustion
fraction have correlation with the fuel ratio of the blended coal.

X［mm］

Change due
to water
conduction

Results of photographing column using
micro-focus X ray CT

System resilience with high integration of renewableenergy sources

See p.30

Fuel Ratio

Before water conduction (200 mL/min for approx.
16 hours)

added value relevant to river environments and ecosystems.

Low

8

slopes become unstable due to an increase in subterranean

structure due to water conduction by using a micro-focus X ray

・With the aim of expanding the eﬀective utilization of coal ash, in order to speed up the leaching test process at

Thermal technology to mitigate environmental load

The combustible componentsof coal are divided into
volatile matter and ﬁxed
carbon. Volatile mattervolatizes from a coal uponheating and have highcombustibility. Fixed carbon
doesn’t volatize and havepoor combustibility. Fuelratio is the ratio of ﬁxed
carbon to volatile matter andif the fuel ratio is high (theamount of volatile matter isminimal), ignitability andcombustibility are poor.

See p.32

・In order to elucidate the mechanism of the phenomena whereby

visually capturing the internal state of change in the sandon-site water system simulator experiments.
A chemical substance thatbonds with metal ionsand increases solubility.

After water conduction

・In order to assess the risk of public damage arising due to theProcessed image

CRIEPI developed a technique to evaluate the eﬀects of chemical treatment based on indoor experiments andChelating Agentfor utilization in preliminary studies when making an operational change.

plants, we applied optical ﬁlter and image processing

succeeded in further reducing sulﬁde corrosion and

A phenomenon whereby
stress works constantly
on metal causing thedistortion to increase overan extended period oftime and ultimately break.

analysis model able to calculate the power generation output and temperature/pressure of complex GTCC plants

obstruction in pulverized coal ﬁred thermal power

prevent sulﬁde corrosion developed by CRIEPI, andCreep Damage(GTCC) which has superior start-up speed and load following ability, CRIEPI built a dynamic characteristics

Flow

Pulverized Coal Fired
Thermal Power
Generation

A power generation
method combining gas
turbine and steam turbine.

conventional power grid, aiming to further improve the operation performance of gas turbine combined cycle

Z
［mm］

2–1.

Outline of Results

Unbalanced Fault
A Fault in which one or
two of three-phase ACtransmission lines (oneset with three) become
temporarily unable totransmit power bylightning, etc.

・To contribute to power system stabilization in the case of increased renewable energy penetration, in addition to
the existing single-phase power source model targeting household solar power generation, CRIEPI developed a3-phase power source model enabling the analysis of an unbalanced fault assuming mega solar and a load supply
system aggregation model including a synchronous machine with renewable energy, which is useful for large-scale
power system analysis.

Expanded introduction of biomass and geothermal power
generation
・To contribute to further popularization of geothermal power generation, CRIEPI conducted the feasibility study of・In order to contribute to stable operation of pulverized coal ﬁred thermal power plants with utilization of low-grade

geothermal power generation systems with even greater eﬃciency and economic performance and indicated that a

fuel, that is used to reduce power generation costs, CRIEPI developed a numerical analysis model to evaluate the

proﬁtable system could be built by using the biomass material obtained in forest thinning as an external heatcombustion condition inside a pulverized coal ﬁred boiler, and clariﬁed the generation and decomposition behavior

source. Moreover, we identiﬁed thirteen prospective locations for the system based on aresult of maps overlayof NOx, that is relevant for air pollution, inside boilers.

analysis using geothermal resource potential and biomass procurement potential in Japan.

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

See p.34

FY2017 Annual Report

9

2–1.

2–1.

Outline of Results
Response to changes in supply form and demand-sidechanges

Electric Power Transmission and Distribution

System resilience with high integration ofrenewable energy sources

Response to reforms in electric power system
CPAT・In order to predict the impact on electrical powersystems of large variation in output of photovoltaic

・In light of the fact that power system operation and planning shall manage increasing uncertainty due to plans for

An integrated software
package developed by
CRIEPI for electrical power
grid analysis. CPAT iscompiled from the three
ﬂagship programs of
power ﬂow analysis,transient stability analysis
and steady-state stability
analysis and is capable ofhighly-accurate analytical
calculation withappropriate consideration
to the various properties
of electrical powersystems.

power generation, CRIEPI developed a technique tothe 2020 legal separation of electrical power generation and transmission and the expanding introduction of

estimate the intensity and variation characteristics

renewable energy, CRIEPI improved the functions of its proprietary“CPAT”software for electrical power grid(standard deviation) of ground surface radiation overanalysis and saw potential for the swift response to various issues of renewable energy sources, systemstabilization device introduction, etc.
・In order to leverage the balancing market to be established by 2021 in line with the electricity system reform and

A program for simulatingtransients of electrical circuits
and their control systems
with its primary application
to power systems. It has
been and is currently
developed by CRIEPI. XTAP
shows advanced simulation
performance over existing
similar programs especiallyfor simulations including
power-electronics converters
such as grid-connection
inverters of photovoltaic
power generation systems.

Sulfur Hexaﬂuoride(SF6)
An insulation gas usedwidely for the insulation ofelectrical devices such as
gasblast circuit breakers andgas insulated switchgears.
SF 6 has been identiﬁed as
being an extremely potent
greenhouse gas.

Lightning Location
System (LLS)
A system with multiple
sensors to detect theelectromagnetic ﬁeld
waveforms generated
from lightning strikes thenestimate lightning location,
time, peak current
amplitudes, etc. based ondata analysis.

The abbreviation ofpolychlorinated biphenyl.
This material was once
widely used in electricaldevices due to its excellent
insulation performance, but
has been prohibited frommanufacture or use due to
its toxic nature. An Act on
Special Measures stipulates
that all PCB-aﬀected devices
must be treated by March
31, 2027.

40°
N

40°
N

30°
N

30°
N

20°
N
120°
E

satellites, as ground surface radiation aﬀects the

Weak

130°
E

140°
E

150°
E

Strong

20°
N
120°
E

130°
E

140°
E

Small

Large

Estimated intensity (a) and standard deviation (b)of ground surface solar radiation

Response to disaster and human risksinterconnections and also for simulations related to integration of renewable-energy generation systems, we haveachieved faster simulation speed for eXpandable Transient Analysis Program (XTAP).
・In order to support the streamlining of operational tasks through linking the various systems of general power・In order to elucidate the cable surf-riding phenomenon that causes[℃]

damage to underground power cables due to vehicles passing

international standard relating to system linkage, for that. CRIEPI investigated the current status of its

3.6
3.0
2.4
1.8
1.2
0.6
0.0
－0.6
－1.2
－1.8
－2.4
－3.0
－3.6

overhead, CRIEPI developed a model test apparatus of one-tenth ofstandardization, as well as examples of application overseas, thus compiling useful information concerning CIM’s

actual size and developed an evaluation model taking account ofapplication in Japan.

most of factors of the surf-riding phenomenon.
See p.44
・In order to improve the accuracy of predicting extreme weather,
CRIEPI developed a data assimilation system to incorporate weather

Formation, maintenance and upgrades of substations andtransmission lines

radar information in model calculation. This has made it possible to
make highly accurate predictions of unexpected weather
phenomenon such as tornados up to several hours in advance(right).

Advancing preservation technology for aged facilities
CRIEPI developed a technique to determine the extent of corrosion from aerial photographs.

10 m/s・In order to improve the prediction accuracy of the damage to power・In order to reduce labor required to judge the necessity of applying anti-corrosive agent to transmission towers,

distribution equipment due to typhoons, CRIEPI introduced the daily

See p.38

sea-level pressure prediction results obtained by the weather

・In order to safely and swiftly measure the density of salt adhered to the surface of insulators used in the insulation

Distribution of airﬂow (vectors) andtemperature deviation (color) inside andoutside tornado-producing cumulonimbus

forecasting and analysis system NuWFAS into the typhoon damageof transmission towers and power cables from the ground, CRIEPI developed a technology to quantify sodium andchlorine using laser-induced breakdown spectroscopy.

150°
E

See p.36

・For power system simulations including HVDC (High-Voltage Direct Current) links used for strengthening wide-are

estimation system RAMP-T. Thus, we made it possible to predict typhoon damage by adding wind velocity

See p.40

information predicted with high precision.

・With the aim of exploring the possibility of utilizing an insulating gas to substitute sulfur hexaﬂuoride as part of a・With the aim of verifying the eﬃcacy of security measures against cyber-attacks on power equipment monitoring

renewal plan for aging equipment, CRIEPI conducted experiments to evaluate the safety and basic insulating

and control systems, CRIEPI built a cyber-security veriﬁcation environment simulating a network control system

performance of an alternate gas currently being researched in Europe and identiﬁed the issues concerningand a substation monitoring and control system.

operational and safety aspects.

See p.46

Support to streamline facility design and operate facilities
・In order to easily determine the damaged point when transmission lines are struck by lightning, CRIEPI veriﬁed theposition location method and the electric charge estimation method in the new lightning location system proposedby ourselves and saw potential to improve measurement accuracy.

Customer Services

・In order to clarify the impact of the electromagnetic ﬁeld created by transmission lines and electrical power
facilities on drones in mid-ﬂight for maintenance andinspection of overhead transmission lines, CRIEPI

Connected manifold +connected pumpdeveloped experiment techniques to evaluate resistanceagainst the three types of ﬁelds, namely a commercial

Oil return due to overﬂow

frequency electrical ﬁeld, a commercial frequency

PCB

（b）
50°
N

output (right).

plan simulation model and automatic generation control simulation model, and clariﬁed the technical challenges
and cost reduction beneﬁts associated with the establishment of a balancing market.

（a）
50°
N

several hours using observed data from weather
variation in a photovoltaic power generation system’s

achieve low-cost, stable operation and control of power systems, CRIEPI developed accurate demand and supply

transmission and distribution businesses, we have proposed to use the Common Information Model (CIM), an

XTAP

10

Outline of Results

magnetic ﬁeld and an electromagnetic ﬁeld radiated fromspark discharge.

See p.42

・In the heated forced circulation washing method to
remove PCB from the contaminated transformers withtrace amount of PCB, there was an issue with insuﬃcientoil circulation when washing large transformers. To solve
this, CRIEPI designed an oil circulation system
connecting two washing units which made it possible towash large transformers by maintaining a suﬃcientamount of circulated oil (right).

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Washing unit

Expansiontank
H P
Connection

pipe

Washing unit

Expansiontank
H P

Oil return
Circulation
washing

Oil delivery
Heating heater andcirculation pump

Promotion of energy conservation and electriﬁcation andenhanced customer satisfaction

P

Transformer
using large
quantity of oil
shown to left
CirculationP

Large-ﬂow
circulation pumpaccessory

Heated washing of transformers using large
quantities of oil with an oil circulation system
connecting two washing units

Heat Exchanger
A device used to transfer
heat from hot substances
to cold substances.

・CRIEPI devised a new heat pump-type AC system for electric vehicles utilizing the Desiccant-Coated Heat
Exchanger (DCHE). By using the dehumidifying ability of the desiccant to prevent condensation from forming on
car windows as well as eﬃciently utilizing the heat generated during dehumidiﬁcation, less battery power isrequired for heating, thus ultimately improving the vehicle’s travel distance.
・In order to contribute to high-level temperature/humidity control in large-scale greenhouses utilizing heat pumps
highly eﬀective at reducing CO2 emissions, CRIEPI developed a wireless IoT temperature/humidity sensor that
operates using a solar cell and makes it possible to measure multiple points cost-eﬃciently.
・CRIEPI developed a novel AI technique that predicts surplus of contract-based electrical power, with the aim ofproviding an e-mail alert service for user cost reduction.

See p.48

Central Research Institute of Electric Power Industry

FY2017 Annual Report

11

2–1.

2–1.

Outline of Results

Outline of Results
Environment

Common in the Multiple Fields
Overall optimization through supply/demand coordination

Response to environmental policy and regulations
・In order to appropriately reﬂect the latest trends regarding global warming countermeasures in the electric power

・With the aim of realizing smart communities, CRIEPI developed a mutual eﬀect analysis tool for communities andbusiness, CRIEPI performed analyses pertaining to carbon pricing and clariﬁed many issues exist in both thepower distribution systems to achieve both rationalized operation and facility construction for power

explicit pricing of carbon tax, emissions trading, etc. and implicit pricing in line with energy-saving relatedtransmission/distribution systems as well as economic community operation.

regulations.
・Toward the goal of establishing measures to reduce CO2 emissions with scientiﬁc and economic rationality, CRIEPI

Common technology for application in diverse ﬁelds

analyzed the economic performance and local receptivity of the CO2 capture and storage technologies proposed as
global warming countermeasures and clariﬁed risk factors in the case that these were introduced in Japan.
・In order to assess the health risks of the intermediate-frequency magnetic ﬁelds used in IH cookers, CRIEPI
performed an exposure experiment using laboratory animals under a magnetic ﬁeld largely exceeding the intensity
stipulated in international exposure guidelines and clariﬁed there was no increase in the incidence of cancer within
the scope of the magnetic ﬁeld and genetically modiﬁed mice model used for the experiment.

See p.50

Eﬃcient environmental assessment

Electric double layerelectret・As part of eﬀorts to establish rational maintenance and operation technology for electric power equipment, CRIEPI

A material with aquasi-permanent electriccharge deviation (electric
double layer) that iscreated by sandwiching
an electrolyte between
electrodes then applying
an electric voltage.

necessary for maintenance-free status monitoring and utilized our original material, electric double layer electrets,

・With the aim of realizing eﬃcient environmental assessments to beimportant bird species, CRIEPI established a technique to analyze areas andtheir importance of the target birds use as feeding and resting grounds basedon ﬂight route data (right).

frequency vibrations 10 Hz or less, which had previously been diﬃcult to accomplish with the conventional
method.
・Long-life rechargeable batteries are essential for system stabilization with increase in renewable energy
introduction and popularization of electric vehicles. CRIEPI developed a technique to predict remaining lives of theaccidents, is also in progress.

the prediction of warm water discharge and cold water discharge as well as
See p.52

to successfully fabricate a vibrational energy harvester capable of generating a voltage of 2 V or more from low

all-solid-state batteries, which consist of ﬂame-retardant materials and are advantageous for risk reduction of ﬁredeveloped a general purpose 3D numerical simulation model applicable to
the recirculation evaluation of intake water.

engaged in activities for the advancement of energy harvesters (environment energy harvesters), which isbatteries, based on the characterization of the positive and negative electrodes of the batteries. Development of

performed when newly constructing or replacing power plants, CRIEPI・In order to evaluate the impact of the location of wind power facilities on

See p.56

Flight path

Major New Research Facilities

LegendSmall
Large
Level of importance

Map showing impact on whooper 10 -5
swan behavior
The areas colored in red show the
impact of a power plant location on
whooper swan behavior, with thedegree of impact being greater thedarker the shade of red.

See p.58

Thermal power water supply treatment tester
This equipment is used to elucidate the corrosion behavior of steam-water
circuits in thermal power plants. The equipment has an injecting system ofchemicals such as ammonia and hydrazine* under supercritical (395℃, 28 MPa)and subcritical (360℃, 22 MPa) conditions. The target of our investigation is,for example, corrosion and fouling of water wall tubes. Hydrazine has been
identiﬁed as a carcinogenic substance. As a result, its use will be regulated inEurope by 2020. Also in Japan, hydrazine will be likely subjected to regulationin near future. The equipment is used for development of an appropriate

Connect & Manage
A scheme allowing theconnection of power
generation facilities withcertain conditions in
response to requests frompower utilities seeking
system connection. The
rules of transmission line
utilization are prioritizing
connection to the powertransmission network(Connect) then minimizing
output in the case ofoversupply (Manage).

Capacity Market
A market that does nottrade supply volume(kilowatts hour: kWh), butrather future supply
capability (kilowatts: kW).
“Capacity market”is ascheme whereby system
operators allocate amonetary value to thecapacity of a power plant,
etc. and trade this on themarket in order to eﬃciently
secure supply capability forseveral years into the future.

12

Utility Management
Ensuring consistency of power system reforms and energy
measures・With the aim of identifying issues with the introduction of“Connect & Manage,”a newly emerged utilization
scheme of power transmission networks, CRIEPI investigated cases of forerunners in overseas locations andclariﬁed the risk of system constraint deviations such as voltage deviation caused by increase of connected power
units as well as excess power ﬂow beyond transmission capacity.
・In regards to the risks that recovery of power source ﬁxed costs may no longer be achievable after electricity
system reform, CRIEPI performed an evaluation based on a simulation of future wholesale electricity prices
together with a survey of overseas trends, and clariﬁed the need for appropriate design of the capacity market
scheme to be established.
・CRIEPI applied its model system to analyze the economic impact if the nuclear power ratio in 2030 was less than
the target indicated in the Long-term Energy Supply and Demand Outlook published by Japan’s Ministry of
Economy, Trade and Industry.

See p.54

・In order to elucidate the factors causing shifts of household/commercial energy demand, CRIEPI performed
analyses of the demand for electrical power and gas by uses as well as by industrial sectors, and clariﬁed thesubstitute of hydrazine.
*Hydrazine: A weak basic substance expressed with the chemical formula of N2H4 which has
been used up to date as a common oxygen scavenger in the high-pressure boilers ofthermal/nuclear power plants.

Radiation sensitivity analysis facility
Amidst a worldwide trend of increasingly-stringent radiation protection standards, the establishment of radiation protection standards
with scientiﬁc rationality based on leading biological research results is imperative. CRIEPI uses this facility to elucidate the mechanism ofdose rate eﬀects on basic carcinogenic inﬂuence.
In addition to utilizing an X-ray microbeam
irradiation device which irradiates cells with
X-ray beams, by using a next-generation DNA
sequencer, the core component of this facility, it
is possible to perform rapid analysis of genetic
information for the irradiated cells. Based on this,CRIEPI is proceeding with a practicaldemonstration of the potential for stem cells toaccumulate mutations and reﬂecting this inradiation protection standards.

See p.22

eﬀects of factors such as income, production, price, no. of household members, temperature, etc. on past demand
trajectories.

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report13List of Research Subjects

List of Research Subjects

Nuclear power generation●Advancements of the safety of light water reactors■ Enhancement of systems and structures to secure safety

・Promotion of Risk Informed Decision Making Process at Nuclear Power Plants■ Establishment of evaluation techniques for
low-frequency phenomena

・Development of Evaluation Method of Fault Activity for Nuclear Facilities
・Development of Evaluation Method of Earthquake Motions for Nuclear Facilities
・Assessment for the risk and hazard of volcanic eruption on Nuclear Facilities
・Development of Extreme Weather Assessment and Countermeasure
Technologies for Nuclear Power Plants
・Development of Tsunami Risk and Impact Assessment Technologies for
Nuclear Facilities
・Development of advanced seismic safety assessment technologies forbuildings, equipment and pipes of nuclear power plants
・Development of advanced seismic safety assessment technologies forgrounds and structures of nuclear power plants■ Advancement of core damage assessment methodology

・Development of safety evaluation techniques prior to core damage
・Technology Development for Performance Evaluation of Nuclear Fueland Reactor Core during Severe Accidents
・Research on Evaluation Technology of Accident Progression and Related
Phenomena after Core Damage

Thermal power generation●Ensuring reliability of existing thermal power plants

・Development of condition diagnostic and maintenance management
technologies of thermal power plants
・Development of on-site diagnostic technique for boiler tube failure inthermal power plant
・Improvement of remaining life assessment, diagnosis and maintenancefor boiler and steam turbine components in thermal power plant
・Development of preventing technology for corrosion and corrosion fatigue
on feed water and steam system components in thermal power plant
・Development of the hard clinker countermeasure in pulverized coal ﬁred boilers
・Development of preventing technology for sulﬁde corrosion on boiler
tube in thermal power plant
・Development of life assessment technology for high temperature structuralcomponents made of high chromium steels in thermal power plants
・Development of maintenance and management technologies for gas turbines
・Development of countermeasures for biofouling and jellyﬁsh invasion atcooling water intake structure of coastal power plant
・Development of performance degradation assessment and enhancement
methods for thermal power civil engineering and building RC structures
・Development of technologies for increasing use of coal ash●Thermal technology to mitigate environmental load
・Development of maintenance and improvement technology ofenvironmental facilities for thermal power plants
・Investigation and Evaluation of the inﬂuence on trend of theenvironmental regulation for thermal power station
・Study on technologies to evaluate the structural integrity of components
in next-generation fossil-fuel power generation
・Development of technologies to improve operation of IGCC plant andreduce environmental loading
・Feasibility study of triple combined cycle system based on pressure
performance of SOFC bench-scale cell・Development of technologies for expanded use of biomass in thermal power generation●Response to reforms in electric power system

・Greater advances in systems to analyze surveys and forecast economicand electric power markets to project demand・Development of support technology for widening system operation andreinforcing system interconnection
・Development of techniques to maintain supply reliability of powersystem under Japanese Electricity System Reform・Development of technologies related to electromagnetic transient
simulations of power systems
・Development of technologies to construct power utilities’ communication
infrastructure utilizing general-purpose communications technology●Formation, maintenance and upgrades of substations
and transmission lines■ Advancing preservation technology for aged facilities
・Diagnostic technology for overhead transmission facilities
・Diagnostic technology for underground transmission cable system
・Diagnostic technology for substation equipment■ Support to streamline facility design and operate facilities

・Development of risk assessment methodology for nuclear facilities
・Development of internal ﬁre and ﬂooding prevent methodology
introducing risk informed evaluation in nuclear facilities●Diversiﬁcation of fossil fuels

・A study on rationalization of insulation design of the power apparatus
and systems based on the lightning risk management
・Solutions for electromagnetic compatibility and electromagnetic
interference (EMC/EMI) caused by HV substations and transmission lines
・Development and estimation of countermeasure technology for fault
currents to secure public safety
・Veriﬁcation of washing mechanism and development of practical washingtechnologies for PCB removal from PCB contaminated transformer
・Development of countermeasures against wildlife causing trouble inelectric transmission facilities
・Development of maintenance and replacement technologies of communication
systems used for power system monitoring, protection and control■ Promotion and advancement of independent public
safety activities●Response to large-scale introduction of renewable energy■ Next-generation equipment technology anticipating
future facility upgrades■ Evaluation of impact of major accidents

・Development of evaluation method of radioactive material in environment■ Establishment of probabilistic risk assessment (PRA) technology

・Development of voluntary safety action programs for nuclear power
stations in consideration of human factors●Safe and stable operation of light water reactors■ Improvement of maintenance techniques for light water reactors

・Development of evaluation techniques for pipe thinning at light water reactors
・Improvement of preventive maintenance technology for LWR components
and piping
・Improvement of water chemistry for dose rate reduction
・Improvement of integrity evaluation method for reactor pressure vessels
・Improvement of integrity evaluation method for core internals, piping
and other components
・Development of nondestructive inspection techniques for components
and piping in nuclear power plants■ Maintenance and expansion of radiation protection systems

・Quantitative evaluation of low-dose radiation risk and reﬂection toradiation protection systems

・Diversiﬁcation Technologies of Fuel Types for Thermal Power Generation
・Development of technology to improve load following capability ofthermal power systems
・Improvement of ﬂexible operations of coal pulverized thermal power
plant and estimation of the value of its ﬂexibility●Response to risk of disasters

・Natural disaster assessment and measures for thermal power plants

Hydropower generation● Disaster prevention and maintenance andmanagement for hydropower facilities

・Development of disaster prevention and maintenance technologies forhydropower facilities●Establishment of nuclear fuel cycle technology

・Development of long-term storage management technologies for spent fuel・Development of technology to improve safety and stable operationsof nuclear fuel reprocessing plants
・Safety assessment for overseas return waste storage
・Securement of options for future nuclear fuel cycle●Support for radioactive waste disposal operations

・Enhancement of reliability of long-term safety assessment technologies
for radioactive waste disposal
・Development of streamlined approach for the implementation ofradioactive waste disposal project●Ongoing long-term use of nuclear reactors

・Technology development for metal fuel fast reactors and pyroprocess●Decommissioning nuclear reactor facilities

・Fundamental technology development for decommissioning anddismantling of nuclear facility
・Development of decommissioning, defueling and remediation
technologies for severe damaged nuclear site

Central Research Institute of Electric Power Industry

FY2017 Annual Report

・Evaluation techniques for power semiconductors
・Development of high eﬃcient electric power distribution facilities for next generation

Customer services●Promotion of energy conservation and electriﬁcationand enhanced customer satisfaction
・Development and evaluation of advanced heat pumps
・Development of energy-saving and electriﬁcation technology inconsumer and industrial sectors
・Research and development for electriﬁcation promotion of thetransportation sector
・Development of Customer Satisfaction Measures utilizing Energy RelatedInformation
・Assessment of the value of next-generation electricity demand management
・Power Retail Business Strategies and Issues in the Post FIT Era

Environment●Response to environmental policy andregulations
・Research on domestic and international climate change policies
・Scientiﬁcally and economically rational scenarios to reduce CO 2
emissions・Health Risk Analysis of Electromagnetic Fields and Other Environmental
Factors
・Analysis of environmental expenditures and source apportionment ofpollutants associated with air quality regulations●Eﬃcient environmental assessment

・Development of advanced and eﬃcient impact assessment methods foratmospheric environment
・Development of advanced and eﬃcient impact assessment methods forcoastal environment
・Improved eﬃciency of assessment of impact on plants, animals andecosystems and development of new evaluation methods●Response to changes in supply form anddemand-side changes■ System resilience with high integration of renewableenergy sources

・Development of next generation power distribution network system
・Development of power system technology contributing to transmission
system resilience with high integration of renewable energy sources
・Development of supply-demand operation and control technology using
energy storage system
・Development of accurate power output estimation and forecast
techniques of photovoltaic and wind power generation
・Performance evaluation of stationary energy storage battery systems forstabilizing power grid connected with renewable energy generation■ Next-generation power distribution system technology
compatible with greater activity in demand region

Utility management●Ensuring consistency of power system reforms
and energy measures
・Issues in institutional design of the electricity system reform
・Analysis for economic impact and political, regulatory and legal risk of
nuclear power in Japan・Analysis and evaluation for policy design to the issues arising with large
scale introduction of renewable energy
・Structural analysis of energy and electricity demand・Power quality preservation and enhancement for distribution systems
with advanced customer devices■ Greater advancements in light water reactor technology

・Technology improvement for performance evaluation of nuclear fueland reactor core

14

Electric power transmission and distribution

Renewable energy● System resilience with high integration ofrenewable energy sources▽ Development of next generation power distribution network system▽ Development of power system technology contributing to transmission
system resilience with high integration of renewable energy sources▽ Development of supply-demand operation and control technology using
energy storage system▽ Development of accurate power output estimation and forecast
techniques of photovoltaic and wind power generation▽ Performance evaluation of stationary energy storage battery systems forstabilizing power grid connected with renewable energy generation▽ Analysis and evaluation for policy design to the issues arising with large
scale introduction of renewable energy●Expanded introduction of biomass and geothermal
power generation
・Development of innovative technologies for promoting the introduction ofgeothermal power▽ Development of technologies for expanded use of biomass in thermal
power generation●Forming, maintaining and update power
distribution facilities
・Development of evaluation technology on lightning risk management
and fault current countermeasures for distribution systems
・Diagnostic technology for power distribution equipment●Response to disaster and human risks
・Evaluation of and countermeasures against earthquake damage to
distribution facilities
・Development of extreme weather forecasting and hazard evaluation
methods for distribution facilities
・Evaluation of and countermeasures against damages meteorologicallycaused to distribution facilities
・Application of disaster mitigation and restoration support technologies
for electric power distribution equipments
・Development of cyber attack corresponding technology for power
equipment monitoring and control system●：Major categories grouping research subjects related to each ﬁeld■：Sub-categories grouping research subjects related to major categories
・：Names of research subjects▽：Research subjects promoted in research issues in other ﬁelds (listed multiple

Common in the multiple ﬁelds●Overall optimization through supply/demand
coordination
・Optimization of advanced power supply and demand management● Trend of develop technology in an overall
electric power industry
・Analysis of global trends of technology development under changing
business environment in electric power industry●Common technology for application in diverse ﬁelds
・Development of advanced sensing technology for power plant components
・Development of high precision and high reliability analysis evaluation
technique・Trend survey of technology utilizing hydrogen
・R&D of Next Generation Electric Energy Storage Technologies
・Development of IoT solutions for Value Added Energy
・ Development of elemental techniques for material strength evaluation
methods utilizing miniature specimens

times)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

15

2–2.

2–2.

Major Research Results-1

Major Research Results–1

Development of an Evaluation Technique for Slope Failure in the
Periphery of Nuclear Power Plants with Application to Actual Site
Clariﬁed the characteristics of slope failure and helped to improve safety of

Nuclear Power
Generation

nuclear power facilities

Background
With the aim of improving the safety of nuclear power plants, in addition to an evaluation of slope failure in the
periphery of nuclear power plants as a phenomena associated with earthquakes, there is also a requirement toevaluate the eﬀects in the case that slope failure does occur. There is a need to conduct suﬃcient studies aimed atpreventing the safety functions of important facilities from being aﬀected in the event that peripheral slope failure
does occur. When evaluating the eﬀects of slope failure, one key item is the evaluation of collapsed rock behavior

A technique for analyzing
discontinuous materials.
DEM expresses theanalysis subject as a massof distinct elements suchas spherical bodies withfree movement andsequentially analyzes the
motion of each element bymodeling the inter-elementbonding, repellence,
friction, etc.

and CRIEPI has developed a technique for such evaluation utilizing the distinct element method (hereinafter“DEM”), etc.
Major Research Results

Major Research Results

Distinct Element Method

Outline of Results◇ Development of a technique utilizing 3-dimensional DEM analysis to evaluate the behavior of massesof rock which have undergone slope failure
Using DEM, CRIEPI developed a technique which makes it possible to identify the reach of masses of rock in the

Nuclear Power Generation

reach of the masses of rock, etc. could be recreated.

Hitoshi Tochigi

External Natural Event Research Team,◇ Development of a modeling technique based on the impact force characteristics upon rock mass
collision and DEM

Nuclear Risk Research Center

In regards to the impact force when a mass of rock collides with facilities, etc., CRIEPI demonstrated it was possible
to make a more realistic evaluation by considering the collision process whereby the mass of rock breaks up to
gradually decrease in size and become small masses of rock by the time of collision (Fig. 1). Moreover, in addition to
elucidating rock mass collisional fracture characteristics through an experiment, we performed a DEM analysis

Engaging in activities for the establishment of a technique to evaluate the eﬀects of slope failure in order to improve the safetyof nuclear power plants.

reﬂecting the results of the collisional fracture experiment and saw the potential for appropriately evaluating theenergy required for rock mass failure (Fig. 2).
No. of particles: 18,900
1.Slope failure, rock mass collapse
Integrated rock massdue to particle bonding

Before fracture

Non-fractured

After fracture

Tensile fracture
Shearing fracture

2.Breakage of rockmass upon collapse
3.Evaluate impact
force of broken
small masses of rock

Assumed slip line

Judging breakage of collapsing rock basedon kinetic energy > collisional fracture energy

Fig. 1 Collapse and collision processes for masses of rock

0.2

－ 0.2
0.4

Before failure

0.2
0.0

0.0

X[m]

0.2

0.4

－ 0.2 Y[m]－ 0.4

Fig. 2 Example of analyzing collisional fracturingof masses of rock using DEM

After failure

Example of slope failure simulation using DEM

Application Examples of Research Results
The evaluation technique developed by CRIEPI is being adopted to assess the impact of slope failures on the emergency access routes andequipment area for implementing measures during major accidents, etc. of nuclear power plants. Moreover, it is anticipated that, moving forward,
the developed technique will help achieve higher accuracy in safety evaluations of nuclear power facilities by being used for slope failure
probability calculation and evaluation of eﬀects on major facilities.

References: Nakase et al., Journal of Japan Society of Civil Engineers A1 (Structural Engineering & Earthquake Engineering) Vol. 71, p. 476 (2015)

16

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

17

Nuclear Power Generation

event of slope failure. As a result of applying this technique to an actual case of slope failure, we veriﬁed that the

2–2.

2–2.

Major Research Results-2

Major Research Results–2

Improved Reliability of Safety Evaluations for Reactivity
Initiated Accidents (RIA)
Helping to improve the safety of nuclear power plants through a thermal-

Nuclear Power
Generation
Reactivity InitiatedAccident (RIA)

Background
In order to evaluate the safety margin when a reactivity initiated accident (RIA) occurs in a boiling water reactor(BWR), there is a need to apply experimental data on thermal-hydraulic behavior during RIAs associated with rapid
boiling inside a fuel rod bundle to the licensing analysis code. In order to experimentally simulate a RIA, which has
been diﬃcult to recreate so far, CRIEPI has developed a rapid heating technology for simulated fuel rod bundles
and an original technology capable of calculating cladding tube surface temperature and boiling/condensing foamvolume under high temperatures and high pressure conditions at a high time/spatial resolution, and is continuously
engaging in research aimed at solving the aforementioned issues.

Outline of Results

Licensing Analysis CodeA calculation code applied
to analytically deriving thetechnical data required forlicensing applications of
nuclear power facilities inaccordance with law.

Major Research Results

Major Research Results

An accident causing thenuclear reactor’s output toincrease rapidly due to thecontrol rod falling or being
projected out and an
abrupt reactivity to be
initiated within the reactor.

hydraulic test simulating the inside of a nuclear reactor◇ Appraisal of the pressure dependence of transient limit heat ﬂux
In order to recreate the rapid heat generation that occurs during an RIA and precisely measure the following
temperature changes, CRIEPI designed and fabricated a thermal-hydraulic simulator that heats simulated fuel with direct
surface. Using this equipment we simulated a state whereby thermal output was rapidly increased instantaneously and

Hiroki Takiguchi / Takahiro Arai

expanded the correlation data of thermal output and temperature to cover the wide pressure scope from atmospheric

Thermal Hydraulics Systems Domain,pressure to the BWR pressure rating (7.2 MPa) (Fig. 1). From this data we obtained new insight relating to pressure
Heat Flux
An amount of heat thatcrosses per unit of area
per unit of time (unitexample: W/m2)

dependence, i.e. the heat ﬂux condition (transient limit heat ﬂux) whereby the cladding tube temperature rises suddenly

Nuclear Technology Research Laboratory

due to water around the rapidly-boiling simulated fuel and the surface of the cladding tube drying (Fig. 2).

◇ Quantiﬁcation of foaming behavior at rapid boiling/condensing using CRIEPI’s original measurement
technology

Nuclear Power Generation

High-temperature/high-pressure RIA simulator
Obtains data on transient limit heat ﬂux through simulating an instantaneous rapid increase in thermal output.

Using CRIEPI’s original void fraction (gas phase volume ratio) measurement technology, we assessed the complex
behavior of the steam-water two-phase ﬂow that boils and condenses within a simulated fuel rod bundle due to asudden increase in thermal output and quantiﬁed the foaming behavior accompanying sudden change inthermal-hydraulic conditions, which is necessary to conﬁrm the adequacy of the licensing analysis code applied to RIA.

Tested portion

Upperelectrode

0.5 MPa
1.0 MPa

Subcooling degree 5℃
Inlet ﬂow rate 0.35 m/s

2.0 MPa
3.0 MPa100

5.0 MPa
7.2 MPa

50

0

100

200

External appearance of the high-temperature/high-pressure RIA simulator

3300

Maximum thermal output within a simulated fuel rod bundle (kW)Fig. 1 Correlation between the maximum thermal output
within a simulated fuel rod bundle and superheating of
the simulated fuel cladding tube surface

2
Subcooling degree is the diﬀerence between theﬂuid temperature and saturation temperature
Inlet ﬂow

Subcooling

0.20

5

rate (m/s)

12degree (℃)

0.35

5

0.50

10

4

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Simulatedfuel rodbundleApplication Examples of Research Results6

圧力（MPa）
Fig. 2 Pressure dependence of transient limit heat ﬂux

CRIEPI deﬁned“transient limit heat ﬂux”as the heat ﬂux at the point where the superheating (temperature diﬀerence in relation to
the saturation temperature at the set pressure) of a simulated fuel cladding tube surface suddenly increases when apredetermined pressure condition and subcooling degree (diﬀerence between the saturation temperature and water temperature
at the set pressure) are established and maximum thermal output is gradually increased. When CRIEPI investigated this transient
limit heat ﬂux in relation to pressure conditions, we observed its tendency to reach its maximum value in the vicinity of 5 MPa.

18

A simulator that recreates a RIA in a BWR fuel rod
bundle using 9 simulated fuel rods (3 bundles
consisting of 3 rods each), with each rod having an
overall length of 3.5 m. At a length of 310 mm, thepoint which equates to an intermediate height,(eﬀective heat generation length), the fuel rods are
instantly heated and the boiling/condensing
behavior of cooling water is measured with highprecision.

Channelbox

Eﬀective heatgeneration length
310 mm0.1MPaTransient limit heat ﬂux (MW/m2)

150

Overall length: 3,500 mm

SpacerMaximum superheating of the simulated
fuel cladding tube surface (℃)

Nuclear Power Generation

conduction up to 20,000 A and includes a simulated fuel rod bundle with a thermometer embedded in the cladding tube

Through applying transient limit heat ﬂux characteristic and steam-water two-phase ﬂow behavioral data relevant to when a reactivity initiatedaccident (RIA) is occurring to the licensing analysis code, CRIEPI will help to increase the reliability of safety evaluations and increase the safetyof power plants.

Reference: Arai et al., Atomic Energy Society of Japan 2017 Autumn Conference, Lecture no. 1C16 (2017)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

19

2–2.

2–2.

Major Research Results-3

Major Research Results–3

Development of Flaw Detection Technology with HighAccuracy for Dissimilar Metal Welds
Helping to improve the reliability of nondestructive examination throughNuclear Power
Generation
Ultrasonic testing

Performance
Demonstration (PD)A method of demonstrating
ﬂaw detection ability in asituation resembling an
actual scenario including theﬂaw detection procedure,equipment and technician
altogether.

A form of age-related
damage that occurs mainly
in metal materials such as
stainless steel andnickel-based alloys. SCC
can occur when susceptible
material, tensile stress andcorrosive environment are
simultaneously present.

Ultrasonic testing is a type of nondestructive examination technology used to detect ﬂaws developing in pipe welds
in nuclear power plants. When examination is highly diﬃcult or high reliability of examination results is required, aperformance demonstration (PD) system is ﬁrst carried out to verify a technique’s ability to detect ﬂaws before thetechnique is applied to actual examination. Due to the diﬃculty of measuring the depth of defects in welds between
low alloy steel and stainless steel by ultrasonic testing, it was preferable to improve the reliability of examination
results through PD system. As the technological foundation necessary to establish PD system, CRIEPI has beendeveloping technologies to fabricate test specimens with stress corrosion cracking (SCC), to evaluate specimen
validity and to size defect depth with high accuracy. CRIEPI has already established the technological foundation
for detecting ﬂaws from the inner surface of welds, and we are continuing our initiatives for ﬂaw detection from theouter surface also.

Outline of Results◇ Establishment of technology to fabricate SCC induced test specimens

Lin Shan

Structural Materials Sector,

Leveraging CRIEPI’s knowledge and examination technologies relating to SCC, we developed a technology tocreate an SCC in test specimens simulating the defects found in actual plants whilst controlling the SCC depth.
SCCs can be created both perpendicular (axial direction) and parallel (circumferential direction) to the weld line,
and have been conﬁrmed as equivalent to the SCCs seen in actual plants (Fig. 1). Furthermore, no noise from
dissimilar metal welds was observed to hinder ultrasonic testing. Through these eﬀorts, we successfully establishedspecimen fabrication technology for PD system associated with dissimilar metal welds.

Nuclear Power Generation

Materials Science Research Laboratory / PD Center
Multi-joint robot scanner
An ultrasonic probe is mounted on an automatically-controlled multi-joint arm and examination is conducted from the outer surface oftest specimen.

◇ Improvement of accuracy of SCC depth sizing from outer surface of pipes
Regarding SCC depth sizing from the outer surface of pipes, CRIEPI developed a new depth sizing procedure
Ultrasonic Phased Array
A technology to control
the direction of ultrasonicwave propagation andfocal position by aspecialized ultrasonicprobe containing many
individual elements thatcan be pulsed separately
with a time delay.

Buttering

characterized by using a larger ultrasonic phased array probe than was previously used, overall rating of ﬂaw

Ultrasonic probe

detection results corresponding to two diﬀerent frequencies and an improved method for identifying the position of
the crack opening. The procedure resulted in dramatically improving depth sizing accuracy, such as decreasing
depth sizing error to around one-quarter of what it had previously been (Fig. 2).

Conceptual image of ultrasonic ﬂaw detection
for dissimilar metal welds (DMWs)
20

300mm

Measured Depth (mm)Nuclear Power Generation

Stress Corrosion
Cracking (SCC)

背景
Background

Major Research Results

Major Research Results

A nondestructive
examination technologythat transmits an ultrasonicpulse to detect the locationand size of ﬂaws such as
internal ﬂaws.

examination of stress corrosion cracking with high accuracy

When welding a low alloy steel vessel to astainless steel pipe,“buttering”is performedon the connecting portion of the vessel side
by adding extra weld metal to increase crack
resistance, and this is then welded to the pipe
side. SCC occurs from inner surface of DMW
therefore such SCCs are examined by placing
an ultrasonic probe on the outer surface ofthe relevant portion.

Axial EDM notch
Circumferential
EDM notch
Axial SCC
Circumferential SCC

15

10

5

0

EDM notch: Notch introduced byelectrical discharge machining

0

5

10

15

20

Portion where SCC
has occurred

DMW

Stainless steel
Pressure vessel, etc.
(low alloy steel)Application Examples of Research Results

Actual depth (mm)Fig. 2 Ultrasonic phased array probe used (left) andcomparison of the depth of SCC in DMW measured fromouter surface with actual depth (right)
1mm

Fig. 1 External view of the fabricatedtest specimen with SCC (top) andcross-section of the SCC created(bottom)

20

Central Research Institute of Electric Power Industry

FY2017 Annual Report

By developing the technological foundation necessary to begin performing PD for dissimilar metal welds, CRIEPI will help to improve thereliability of examination results when performing nondestructive examinations that conﬁrm plant integrity.

The mean square root error, which is an indicator of depth sizing
accuracy, was around 4 mm in previous studies, however CRIEPI’s
eﬀorts have reduced this to around 1 mm.

Central Research Institute of Electric Power Industry

FY2017 Annual Report

21

2–2.

2–2.

Major Research Results-4

Major Research Results–4

Veriﬁcation of dose Rate Eﬀect based on the Mechanismof Cell Competition
Contributing to the evaluation of radiation risk based on scientiﬁc data

Nuclear Power
Generation

Background
Cancer risk due to low-dose-rate radiation exposure is generally known to be lower than that to high-dose-rate
exposure. The results of epidemiological studies of high background radiation areas revealed that the risk of

An independent,
international academicorganization that provides
recommendations onradiological protection
from an expert standpoint.

phenomenon whereby the stem cells that have not been irradiated (non-irradiated stem cells) and the stem cells thatthe dose rate eﬀect. Unlike high-dose-rate cases in which all cells are irradiated by radiation, low-dose-rate
exposure is where both irradiated cells and non-irradiated cells coexist. Radiation-induced stem cell competition is ahave been irradiated (irradiated stem cells) compete with each other and the loser is more likely to be excluded
from the tissue. In order to substantiate dose rate eﬀect from a biological mechanism, CRIEPI has created anexperimental system that enables the observation of radiation-induced stem cell competition, and is engaging inresearch activities.

Dose Rate Eﬀect
A state whereby the
biological eﬀects are said
to be greater if the sameamount of radiation is
irradiated at a high-doserate over a short period oftime than a low-dose-rateover a long period rate.

Stem Cell
Cells with the ability to
re-produce and replenish
cells that have died inorder to maintain tissue inwhich individual cells witha short lifespan are
constantly replaced.

Outline of Results◇ Quantiﬁcation of radiation-induced stem cell competition

Masanori Tomita / Yuki Fujimichi

CRIEPI has established a system to eﬃciently form organoids (cell cultures formed in vitro with a structure

Radiation Safety Research Center,

representing actual organs) containing stem cells, which are known as the origins of cancer. By using theseorganoids derived from irradiated and non-irradiated stem cells labeling (identifying) with diﬀerent ﬂuorescent

Nuclear Technology Research Laboratory

colors, CRIEPI has developed a technique achieving the visualization and quantiﬁcation of the stem cell competition
that takes place between these two stem cell types. As a result of cocultivating stem cells with diﬀerent irradiation
conditions, it was indicated that the proliferation of irradiated stem cells is diﬃcult (Fig. 1) and we veriﬁed feasibility

Nuclear Power Generation

Stem cell analysis device (cell sorter)

A device to analyze and sort the targeted stem cells from a mixed state.

of a hypothesis for the mechanism of dose rate eﬀect.

Overview of the mechanism of dose
rate eﬀect due to cell competition◇ Gene identiﬁcation tying dose rate eﬀect to cell competition
Using CRIEPI’s radiation sensitivity analysis facility (see p.13 [Major New Research Facilities]), we compared theGene Expression
The process whereby
genetic information isconverted to structure andfunction within cells.
Speciﬁcally speaking, gene
expression normallyindicates protein synthesis
based on genetic
information.

overall gene expression level of colon stem cells in mice irradiated with the same dose of radiation at diﬀering dose

For tissue preservation
purposes, the stem cell
population is kept to acertain number

radiation

result of introducing such genes to the cultured cells and conducting observations, we observed that the cells which
expressed the activated genes were surrounded by the cells that did not, defeated in competition, and then expelled(Fig. 2). These results showed that these genes tie dose rate eﬀect to cell competition.

Radiation

Radiation

Stem cell ratio =Number of non-irradiated stem cells
identiﬁed by ﬂuorescent color

1 hour after observation start

3 hours later

12 hours later

1.0
0.8

Cocultivation of nonirradiated stem cells
and irradiated stem
cells

0.4

0.0

0.0

0.2

0.4

0.6

0.8

1.0

Fig. 1 Comparison of number of
non-irradiated stem cells ratio
before and after co-cultivation

Central Research Institute of Electric Power Industry

100µm

Fig. 2

Cocultivation of nonirradiated stem cells

0.2

FY2017 Annual Reportradiation

ExpulsionCompetition
Division

Replenishment
補充
Damaged cells
accumulate andnormal cells
disappear

0.6

Low-dose-rate

Cell death

Total number of stem cells

Stem cell ratio before co-cultivation

22

High-dose-rate

rates and extracted the genes that were speciﬁcally activated (switched on) in the case of low-dose-rate only. As a

Stem cell ratio after co-cultivation

Nuclear Power Generationdose rate of Japanese people. The ICRP proposed“radiation-induced stem cell competition”as one mechanism ofMajor Research Results

Major Research Results

carcinogenesis does not increase at an annual dose rate between around 5 to 10 times greater than the average
ICRP(International Commission
on Radiological Protection)

100µm

100µm

Cells which express the gene determining dose rateeﬀect are expelled due to cell competition

Identiﬁcation of the gene groups in the colon stem cells of mice
which are activated during low-dose-rate exposure. It was
conﬁrmed that genes which did become activated (shown in red)
became small spheres and were expelled from the cell population(defeated in competition) (the red color of the cells indicated in
the ﬁgures using white arrows became more distinct over time.)

Replenished withdamaged stem cells

At high-dose-rate
exposure, all cells
are damaged
simultaneously

At low-dose-rate
exposure, all cells
are not damaged
simultaneously

Competition occurs if
the cell population
exceeds a certain
amount during division

Damaged cells are
expelled and anormal group ismaintained

Application Examples of Research Results
With the aim of having these results reﬂected in the next main recommendations by the ICRP, CRIEPI will accumulate more quantitative data
relating to dose rate eﬀect due to radiation-induced stem cell competition and convey such data through academic papers, etc.

References: Otsuka et al., J. Radiat. Res., doi: 10.1093/jrr/rrx078 (2017 epub)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

23

2–2.

2–2.

Major Research Results-5

Major Research Results–5

Development of a Method to Detect Helium Leaks
from Canisters Inside Concrete Casks
Contribution to improved safety and practical application of spent fuel storage

Nuclear Power
Generation

BackgroundIn consideration of the increase in spent fuel due to the restart of nuclear power plant operation and thecontinue using the metal casks already in practical use alone from the perspective of manufacturing capacity, thus

Concrete Cask
A cylindrical container
used for storing spent
fuel. A concrete casks iscomprised of a stainlesssteel canister which seals
spent fuel and a concrete
storage container whichshields neutrons. The
decay heat of spent fuelis removed by naturalconvection generated on
the canister’s surface.

there are expectations for the practical application of a storage system using the concrete casks because of theircost-eﬀectiveness and relatively-quick manufacturing. However, there is concern that in the concrete casks, salt inoutside air could cause stress corrosion cracking (SCC) to the canisters during the storage period, resulting in a lossof sealing performance. In order to realize the practical use of concrete casks in Japan, it is expected not only topromote SCC measures, but also to develop a technique to detect even minute leaks in order to improve the safety
in case of such a leak event.

Outline of Results◇ Development of a method to estimate leak amount of helium from canisters
We made a small-scale cask model capable of simulating a heat transfer phenomenon that occurs within an actual

Nuclear Power Generation

Hirofumi Takeda

canister, and performed a ﬂow experiment and ﬂow analysis simulating a helium leak from a canister (Fig. 1). Basedon these results, we measured the increase in the diﬀerence between the temperatures at the canister’s bottom (TB)

Nuclear Fuel Cycle Backend Research Center,and at the canister’s lid (TT), so as to develop a method for estimating the leak amount ratio to each heat rate in

Civil Engineering Research Laboratory

the canister. Compared to the metal cask in which a pressure gauge is installed, this method realizes low cost andeasy maintenance in the concrete cask as a thermo-sensor is installed only on the exterior surface of the canister.
Moreover, there is no need to make a hole for installing the thermo-sensor in the canister, therefore no more leak

766ｍｍ

Heating
element

TT

Canister

Cask

TB
Low

Temperature

High

Valve

Small-scale Cask Model(1/4.5 scale)

Temperature Distribution
based on Analysis

ΔTBT increase amount (℃)

risks are created.

1272ｍｍNuclear Power Generation

its spent fuel countermeasure action plan. Due to the increase in the amount of dry storage, it would be diﬃcult to

A method of storing spent
fuel in a metal container
including inert gas (helium,etc.). A method of storing
spent fuel in a water pool isreferred to as wet storage.

Major Research Results

Major Research Results

decommissioning of the reactors, the Japanese government has indicated the need to strengthen storage capacity in
Dry Storage

Equivalent to 10 kW in an actual canister(after 40-year storage)
Equivalent to 5 kW in an actual canister30

Small-scale Cask Model
Based on the similarity law of thermal-hydraulics, the ﬂow similar to that in the actual cask during the helium leak is reproducible.

Air outlet

The temperatures are derived by converting

25

test values to actual unit values. For example,

20

value of 10 kW increases by 5℃ in a no leakAir outlet：Air ﬂow

if ΔTBT (=TB-TT) in a canister with a heatstate, a 40% leak is determined.

15

Shielded lid

10Canister

50Concrete module

0

10

20

30

40

50

60

70

80

Leak amount ratio (%)

90

100

Support frame

Example of a Design Concept of
a Horizontal Silo Storage System

Leak Amount Ratio and Increase in Diﬀerence
Between Temperatures at Canister Top/Bottom

Fig. 1 Small-scale Cask Model, Results of In-cask Flow Analysis, and Leak Evaluation Method

Air inlet

Application Examples of Research Results◇ Development of a leak detection method applicable also to horizontal silo storage systems

By developing the leak detection method with high sensitivity, the safety and reliability of the concrete casks are improved, which leads to their

We performed a leak test/analysis using a small-scale canister model aimed at horizontal storage of the canister

reduced.

(ﬁgure on the right-hand page), and selected temperature measurement points to detect the leaks. As a result, in theearly introduction in Japan. Moreover, if the requirement for SCC inspections is eliminated or mitigated, inspection fees will be signiﬁcantly

same way as the vertical storage, it was observed that the temperature at the bottom of the canister increased most,while the temperature at the lid decreased most during the leak. Furthermore, because the temperature of the lower
side part increased while that of the upper side part decreased, it was demonstrated that the leak detection using
the temperature diﬀerence is possible by combining the temperatures of these four measurement points.

24

Central Research Institute of Electric Power Industry

FY2017 Annual Report

References： Takeda et al., CRIEPI Research Report N17007 (2018)
Takeda et al., CRIEPI Research Report N17013 (2018)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

25

2–2.

2–2.

Major Research Results-6

Major Research Results–6

Improvement of the Vitriﬁcation Process in Spent Fuel
Reprocessing Plants
Contributing to enhance the safety of high-level radioactive waste disposal

Geological Disposal

The highly-radioactive liquid waste separated in the reprocessing of spent fuel is vitriﬁed to stabilize andA method of burying
high-level radioactive waste
deep underground andisolating it safely and withcertainty over a long periodof time so as not to impact
the living environments ofhumans.

geologically disposed of as high-level radioactive waste. However, some elements tend to precipitate in the glass
due to limited solubility. The two main types of such precipitates are a crystal phase called yellow phase (YP) which
is water soluble and reduces safety upon disposal, and the needle-like crystals of platinum group element oxides
that obstruct the stable melting and pouring of glass during vitriﬁcation. In order to ﬁnd a comprehensive solution
based on an understanding of the phenomenon, CRIEPI is working to clarify the mechanisms that generate theabovementioned substances.

Yellow Phase
A water-soluble compoundwith the primary element ofmolybdenum formed in theglass melting process.
Yellow phase is heavier thanmolten glass, therefore
remains at the bottom ofcanisters and has thepotential to increase the riskof radioactive substancesleaching upon geologicaldisposal.

Platinum Group
Elements
A group of elements in the
periodic table including
ruthenium (Ru) andpalladium (Pd). Ru and Pd
are present in spent fueland migrate to high-levelliquid waste during
reprocessing.

Outline of Results◇ Clariﬁcation of the mechanism of yellow phase formation

Kazuyoshi Uruga / Tsuyoshi Usami

CRIEPI fabricated a small scale glass melter enabling the detailed observation of glass melting behavior andperformed experiments. As a result, we clariﬁed that the main element of YP, molybdenum (Mo) primarily forms

Fuel Cycle Sector,

molten salt with sodium (Na), aggregates, and settles without dissolving into the glass as yellow phase.

◇ Clariﬁcation of the mechanism for generating needle-like crystals of a platinum group element
CRIEPI elucidated that ruthenium (Ru) oxide, the main platinum group element in spent fuel, reacts with sodium

Nuclear Power Generation

Nuclear Power Generation

Background

Major Research Results

Major Research Results

Nuclear Power
Generation

Nuclear Technology Research Laboratory
Small scale glass melter
Enables detailed observation of the behavior of glass melted at high temperature and liquid waste.

once to form a needle-like intermediate compound. The sodium in the compound dissolves into molten glass, andneedle-like crystals of ruthenium oxide (RuO2) grow radially.

◇ Proposal of a countermeasure focused on sodium

Highly-radioactive
liquid waste

Glass beads(Na, Fe, Mo, Ru etc.)(Si, B, Al, Ca etc.)

Since sodium is a highly contributing to the formation of both YP and needle-like crystals of a platinum groupelement, it was considered be eﬀective in suppressing each substance to dissolve sodium into the glass before it
reacts with molybdenum and ruthenium. As one concrete countermeasure, we proposed to enhance the dissolution

Overview of a glass melterof sodium into glass by using glass material in a powder form.

Formationmechanism ofyellow phase
Mo

Position withinglass melter

Ca
CaMoO4

Reaction with sodium
Liquid phase aggregateson the molten glass

Na

Upper
part

Glass
temperature (℃)
500

600

Ca
Na2MoO4(YP)

Formation mechanism ofneedle-like crystals ofa platinum group element

RuO2

700

800
Lower
part

Reaction with sodium

Na

Na3RuO4

RuO2
Precipitates on the melterbottom without dissolving
into the molten glass

1mm

Na

10μm

Formation of a needle-likeintermediate compound
Sodium is dissolved
into molten glass

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Moltenglass

Mainelectrode

Refractory
brick
Bottom electrode
Pouring to container for vitriﬁed
substances (canister)

Application Examples of Research Results
The results of this research have been reﬂected in the improvement/development plans for vitriﬁcation facilities in Rokkasho reprocessing plant. It
is anticipated these results will help to achieve stable operation of reprocessing plant and improve safety concerning the geological disposal ofradioactive waste.

Clusters of RuO2 needle-likecrystals settle and builds
up on the melter bottom

Overview of the formation mechanisms for yellow phase and needle-likecrystals of a platinum group element in a glass melter

26

Highly-radioactive liquid waste and glassmaterial are supplied into the glass melter,
molten through Joule heating using
electrodes then poured into a stainless steel
container for vitriﬁed substances (canister)from a nozzle located at the bottom. The
temperature within the melting furnace isaround 130℃ at the top however the centerof the melted glass reaches around 1,150℃.

References： Usami et al., Proc. of Global2015, Paper5186 (2015)
Uruga et al., Proc. of Global2015, Paper5191 (2015)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

27

2–2.

2–2.

Major Research Results-7

Major Research Results–7

Proposal of a Method for Planning the Timing of Chemical
Cleaning based on Monitoring of Creep Damage Status
Supporting to reduce maintenance costs through the rationalization of chemical

Thermal Power
Generation
Creep Damage
See p.8

cleaning plans for boiler water wall tubes

Background
Chemical cleaning is carried out on the boilers of thermal power plants to prevent creep failure, etc. that occurs in
the tube material due to an accumulation of scale on the inside of the water wall tubes over the course of the boiler’s
operation. The basis of the current chemical cleaning standards for water wall tubes is base load operation fromaround the 1980s whereby the allowable scale accumulation is determined by the allowable temperature of the tube
material which is determined uniformly, therefore the impact of stress and temperature ﬂuctuation during theoperation of each individual boiler is not taken into consideration. As a result of investigating the degree of damage
to the material used in actual boilers, CRIEPI judged there was potential to rationalize the chemical cleaning

Major Research Results

Major Research Results

standards. In order to secure water wall tube reliability and reduce maintenance costs, CRIEPI proposes a techniqueto judge the appropriate timing for chemical cleaning based on the individual operating conditions of each boiler.

Outline of Results◇ Evaluation of creep damage status based on a creep test and metal temperature analysis
In order to assess the status of creep damage in the water wall tubes of actual boilers, CRIEPI performed creep tests

Thermal Power Generation

using the material strength characteristics obtained in these creep tests and the analysis results of the metal

Thermal Power Generation

on sampled tubes and an analysis of data from the thermometer installed in the ﬁreside of water wall tubes. By

Masahide Yoshida / Masahiko Morinaga

temperature data, it was possible to visualize the creep damage status in relation to operating time. This enables theprediction of the chemical cleaning implementation limit from the status of creep damage in water wall tubes, andThermal Power Operation/Maintenance Sector,

determine the minimal required chemical cleaning count until the target life (Fig. 1 (a)).

Energy Engineering Research Laboratory◇ Proposal of a method for planning chemical cleaning timing
In the method of planning the timing of chemical cleaning proposed by CRIEPI (which uses creep damage status as
the index for timing chemical cleaning instead of the conventional scale accumulation amount) if the timing ofchemical cleaning is changed based on the minimal required chemical cleaning count, it is possible to quantitatively

Miniature creep test unit for inert gas environments
A unit that performs a creep test on test specimens prepared from sampled tube material in an argon gas atmosphere.
The results obtained from this unit are utilized for the visualization of creep damage status.

that minimizes creep damage when the target life is reached and reduce the risk of unscheduled stoppages resulting
from the bursting, etc. of water wall tubes.
Timing of Linechemicalcleaning color
Implementation
Case A
limit
Chemical cleaning
Case B 60,000 hours
Case C 50,000 hours
Case D 40,000 hours
Case A

0.5
0.4

Constant creep
damage ratio case

0.3
0.2
0.1
0.0

ー

tio
e ra

＊2

e
cas

Chemical cleaningagamCase Bp d Chemical cleaningreectn Chemical cleaning
a
Case
C
t
ns
Co
Case D
0

Implementation limit of chemical cleaning Target life
20,000 40,000 60,000 80,000 100,000
Operating time［h］

Fig. 1 (a)Change in creep damage status due tothe timing of chemical cleaning

0.5
Remaining creep life
at 100,000 hours［ー］

Creep damage ratio＊1
［ー］

Name

0.4
0.3
0.2
0.1
0
20,000DC40,00060,000・Setting of boiler target life
・Creep test using sampled tube material＊3

Assessment ofdamage status

・Analysis of water wall tube temperature・Calculation of creep damage ratio

Reduction of・Determination of the implementation limit for the timing of chemical cleaning
maintenance cost ・Determination of the minimal target life chemical cleaning count until target life

Ｂ

Timing of chemicalcleaning where therisk is the lowest in thecase of one chemicalcleaning at the target
life of 100,000 hours

Preparation

Securing reliability ・Calculation of creep damage ratio upon change to timing of chemical cleaning・Determination of timing of chemical cleaning where risk is minimal
A＊3 Sampled tube material：Tube material used in actual boilers is sampled and utilized for creep tests

Flow of method for planning timing of chemical cleaning
80,000Timing of chemical cleaning［h］

Fig. 1 (b)Change in remaining creep life due tothe timing of chemical cleaning

Creep damage ratio［ー］

conﬁrm the impact on creep damage status (Fig. 1 (b)), therefore it is possible to determine a timing for cleaning
0.003
Right wall
Rear wall

0.002

0.001

0.000

0

5,000 10,000 15,000 20,000
Operating time［h］

Visualization of the creep
damage condition

By focusing on the tube
strength/temperature/stresscondition of each individual
boiler, and using creep
damage status as anindicator, the minimum
necessary chemical cleaning
count until target life isdetermined (reducing
maintenance cost), and thetiming of chemical cleaning
to minimize creep damage isdetermined (securing
reliability).

Application Examples of Research Results
The method of planning timing of chemical cleaning can be applied to boilers with water wall tubes installed thermometers in the ﬁreside inthermal power plants. By applying this planning method to actual boilers it is possible to achieve monitoring of water wall tube status and support
formulation of a chemical cleaning plan aimed at securing reliability and reducing maintenance costs.

Fig. 1 Change in creep damage status and remaining creep life due to the timing of chemical cleaning
By forecasting the remaining creep life (remaining life) of water wall tubes after cleaning by cleaning cases(timing) until the chemical cleaning limit time, the optimal timing of chemical cleaning can be determined.
＊1 Creep damage ratio：A value expressing the progress of creep damage whereby new material is 0 and creep rupture is 1.
＊2 Constant creep damage ratio case：A rupture of the tube material is considered as creep damage ratio 1, while the creep damage ratio limit is set at 0.5. Theline along which creep damage of the water wall tubes is hypothesized to progress at a constant rate until target life (100,000 hours in this case) is reached.

28

Central Research Institute of Electric Power Industry

FY2017 Annual Report

References： Morinaga et al., 23rd National Symposium on Power and Energy Systems, Lecture no.D125 (2018)
Morinaga et al., CRIEPI Research Report M15008 (2016)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

29

2–2.

2–2.

Major Research Results-8

Major Research Results–8

Development of a Carbonized Woody Biomass Fuel Capableof High Co-ﬁring Rate in Coal Fired Thermal Power Plant
Contributing to the reduction of CO2 emissions through the co-ﬁring ofThermal Power
Generation

carbonized woody biomass fuel and coal

Background
In order to realize the Japanese government’s goal of reducing greenhouse gas emissions to 26% by FY2030 (comparedto FY2013), there is a need to reduce CO2 emissions in every ﬁeld and the technologies to achieve this are currently
being developed and veriﬁed. Coal ﬁred power plants are promoting the co-ﬁring of carbon-neutral woody biomass
with the aim of reducing CO2 emissions, however the co-ﬁring of wood chips, etc. entails the issues of grindability and

Improved fuel made fromwoody biomass that has
undergone the pre-treatmentof carbonization, molding, etc.
Through the improvement
process, the grindability, etc.
is enhanced, making it
possible to use the woody
biomass-derived fuel in almost
the same way as coal.

supply capability. In order to resolve these issues, CRIEPI is engaging in the technological development of carbonizedwood fuel with the aim of expanding the utilization of biomass in coal ﬁred thermal power plants.
Major Research Results

Major Research Results

Carbonized wood fuelOutline of Results◇ Evaluation of the grindability of carbonized wood fuelWith the aim of reducing CO2 emissions in coal ﬁred thermal power generation, CRIEPI improved the grindability
and caloriﬁc value of woody biomass through carbonization and developed a carbonized woody biomass fuel for use

Thermal Power Generation

Maromu Otaka

testing, CRIEPI noted that the power required to grind carbonized woody biomass fuel was almost equivalent to that

Energy Platform Creation Sector,

required for bituminous coal, therefore it would be possible to introduce carbonized woody biomass fuel to coal ﬁred

Energy Engineering Research Laboratory

thermal power plants without modifying conventional equipment (coal mill modiﬁcation, etc.).

◇ Beneﬁts associated with a high co-ﬁring rate of carbonized wood fuel
CRIEPI performed mono-ﬁring tests of coal and carbonized woody biomass fuel respectively on its own coal
combustion test furnace. Because carbonized woody biomass fuel contains less nitrogen than coal and hardly any
sulfur, there are expectations that the amount of NOx and SO2 in combustion exhaust gas can be reduced throughFuel carbonization test unit
Fabrication test of carbonized fuel derived from raw materials such as woody biomass, etc. and evaluate the carbonization property of
the raw material. The manufactured carbonized fuel is utilized as test fuel to evaluate the grindability when mixed with coal and co-ﬁring
characteristics.

co-ﬁring in coal ﬁred thermal power plants (Fig. 1). CRIEPI tentatively calculated the CO 2 emissions and combusted
coal emissions in the case that carbonized woody biomass fuel was introduced to coal ﬁred thermal power plants.
By comparing coal mono-ﬁring and carbonized woody biomass fuel co-ﬁring (co-ﬁring rate of 30% (caloriﬁc value
basis)), CRIEPI recognized that it was possible to reduce CO2 emissions by approximately 860,000 tons annually(Fig. 2 (a)). Moreover, due to the fact that carbonized woody biomass fuel contains less ash than coal, (coal:approx. 10%, carbonized woody biomass fuel: 1% or less), the combusted ash output is reduced by around 27,000
tons annually when carbonized woody biomass fuel co-ﬁring is introduced (co-ﬁring rate of 30%), therefore it is

350
300
250

362

Coal
Carbonized woody
biomass fuel
235

200
150
100

116

50
0

2
NOx

SO2

Fig. 1 Comparison of NOx and SO2
concentration at furnace outlet in thecase of mono-ﬁring

30

Central Research Institute of Electric Power Industry

FY2017 Annual Report

350
300

289

250
200

203

150
100
50
0

Coal
Carbonized woody
mono-ﬁring biomass fuel co-ﬁring(a) CO2 emissions

Combusted ash output［10,000 T/year］

400

CO2 emissions［ 10,000 T-CO2/year］

Concentration of ﬂue gas［PPM］

possible to reduce the costs involved in ash processing (Fig. 2 (b)).
12
10
8

10.5
7.8

Application Examples of Research Results

6
4

We aim to reduce the CO 2 emissions associated with coal ﬁred thermal power generation through the popularization of carbonized woody
biomass fuel suited to a high co-ﬁring rate. This will contribute to the realization of a low-carbon society.

20

The manufactured carbonized woody biomass fuel

Coal
Carbonized woody
mono-ﬁring biomass fuel co-ﬁring(b) Combusted ash output

References： Report on the Results of the Low Carbon Technology Research and Development Program FY2016 (Ministry of the Environment)

Fig. 2 Tentative comparison for CO2 emissions (a) andcombusted ash output (b) with coal mono-ﬁring andcarbonized wood fuel 30% co-ﬁring respectively“Establishment of an energy independent manufacturing process for the expansion of bio-modiﬁed coal and development of 100% mono-ﬁring

Coal ﬁred power plants：Power generation output of 500 MW,
power generation eﬃciency: 40%, annual facility utilization rate: 80%“Practical application for a wood biomass improvement process to realize a 30% co-ﬁring rate in coal ﬁred thermal power generation”(2015)

technology for pulverized coal boilers”(2017)
Report on the Results of the Low Carbon Technology Research and Development Program FY2014 (Ministry of the Environment)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

31

Thermal Power Generation

at a high co-ﬁring rate in coal ﬁred thermal power generation. Through a grindability evaluation using a roller mill for

2–2.

2–2.

Major Research Results-9

Major Research Results–9

Development of a Technique for Assessing the Risk of
Public Damage Imposed by Hydropower Facilities
Supporting assessment of and countermeasures to natural disaster risks

BackgroundKumamoto
Earthquakes

In light of the lessons learnt in the 2016 Kumamoto Earthquakes, there are now requirements to assess the risk of

The earthquakes that
occurred with an epicenter inthe Kumamoto region ofJapan were termed the“2016Kumamoto Earthquakes”
collectively. Earthquakes ofthe maximum seismic intensity
7 were observed twice; April
14th and April 16th, andthese caused a severe amountof damage, including thecollapse of several house,primarily in Kumamoto
prefecture.

the prioritization of natural disaster countermeasures. However, each electric utility manages an enormous number

public damage arising from the damage or destruction of hydropower facilities in the event of natural disasters andof hydropower facilities, and it is not easy to swiftly assess the risk of public damage for all facilities based onrational criteria. As such, CRIEPI is engaging in the development of a tool enabling the people in charge at eachelectric utility to simply and rationally assess the risk of public damage of each hydropower facility belonging tohis/her company.
Major Research Results

Major Research Results

Hydropower
Generation

Outline of Results◇ Development of a ﬂooding analysis technique
Flooding damage due to water runoﬀ from head tanks and penstock pipes is perceivable as one form of public
damage concerning hydropower facilities. As such CRIEPI established a program able to quantitatively analyze theHydropower Generation

Hydropower Generation

scale of ﬂooding simply by specifying a small number of conditions including runoﬀ amount and runoﬀ time. This
analysis can be performed for all regions of Japan using nationwide altitude data prepared by the Geospatial
Information Authority of Japan. CRIEPI also established a system to display the calculated results for ﬂood range,

Ryosuke Arai / Kazuyuki Ota

etc. on maps so that areas with high risk of public damage can be clearly recognized immediately.

Fluid Science Sector,

Civil Engineering Research Laboratory◇ Development of a debris ﬂow analysis
In recent years, a concern has risen regarding debris ﬂow in line with an increase in localized torrential rain. Due tothe fact that hydropower facilities are generally located in mountainous regions, debris ﬂow is considered a natural

Engages in the development of a technique to assess the natural disaster risk of hydropower facilities.

disaster risk that could damage hydropower facilities. As such, CRIEPI has established a program that can simply
and rationally analyze debris ﬂow. This program is capable of not only displaying the range impacted by the debris
Hydrodynamic Force“Hydrodynamic force”
means the force of a ﬂuid
and is used as an indicatorof the impact ﬂuid has ona structure.

ﬂow, but also the hydrodynamic force of the debris ﬂow at the hydropower facility, therefore it can be used by the
persons in charge at each electrical utility for the assessment of the natural disaster risk towards each facility.

App for displaying results

Input data

✓ Runoﬀ time
✓ Runoﬀ amount✓ Roughness
coeﬃcient

Windows PC

Latitude andlongitude designation
Deep

High

Program utilization steps

Application Examples of Research Results
Shallow

Flood analysis result (left) and debris ﬂow analysis result (right)
The ﬂood analysis result expresses ﬂood depth, while the debris ﬂow analysis result
expresses the height of the debris ﬂow deposition height. As the ﬁgures show, results canbe displayed on either an aerial photo or a ﬁgure from the Geospatial Information
Authority of Japan.

Low

The ﬂooding analysis program and debris ﬂow analysis program are adopted by the various electric utilities and are being used for analysis andassessment purposes by the respective people in charge.

References： Arai et al., 13th International Hydroinformatics Conference (2018)
Ota et al., Japan Society of Erosion Control Engineering Journal (2018)

32

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

33

2–2.

2–2.

Major Research Results-10

Major Research Results–10

Development of Hybrid Power Generation Technology
Utilizing Geothermal Energy and Biomass
Contributing to further popularization of geothermal power generation throughRenewable
Energythe feasibility study of the hybrid power generation system

Background
Power generation facilities using renewable energy with minimal CO2 emissions are being introduced more andmore as an initiative aimed at realizing a low-carbon society. According to the“Basic Energy Plan”in Japan, it wasyear 2030. Since the conventional geothermal power generation system utilizes the geothermal saturated steam with

Steam separated in amoisture separator from thetwo-phase ﬂow that rises
up from undergroundminimal at only slightly over 10%. CRIEPI is promoting the development of a more eﬃcient and economic

a low caloriﬁc value that rises up from production wells, there is a problem that the power generation eﬃciency was
geothermal power system in order to help expand the regions where geothermal power generation can be applied(This project was supported by New Energy and Industrial Technology Development Organization (NEDO)).

Major Research Results

Major Research Results

set the goal of increasing the capacity of geothermal power facilities from the current 500 MW to 1,500 MW by the
Geothermal Saturated
Steam

Outline of Results◇ Potential for the introduction of hybrid power generation systems

Yoshinobu Nakao

CRIEPI conducted the feasibility study of a hybrid power generation system (power generation eﬃciency of 20% or

Renewable Energy

generation cost, we clariﬁed it would be between 25 and 30 yen/kWh. Since the cost is less than the FIT price (40yen/kWh) for geothermal and biomass power generation, we can anticipate the commercialization of hybrid power
generation systems. We also conducted a survey to evaluate which regions in Japan had high potential as locations
for the introduction of hybrid power generation systems. As a result of maps overlay analysis using geothermal
resource potential and biomass procurement potential, then reﬁning our results with the conditions of geothermal
resources of at least 150℃ as well as biomass reserves of at least 5,000 ton (dry weight)/year, we identiﬁed 13

Geothermal steam superheating test facility
A testing apparatus to observe the status of scale adhesion and corrosion resulting from the geothermal steam superheating test.
Geothermal saturated steam provided from the production well is directly supplied to the heat exchanger pipe and can be superheatedupto a maximum of 400℃.

Boilerprospective development locations in Japan, including Hokkaido, Tohoku and Kyushu region (Fig. 1).

◇ Small-scale veriﬁcation test for hybrid power generation system
In the practical application of a hybrid power generation system, one issue that needs to be addressed is blockageof heat exchanger pipes due to scale adhesion of silica or calcium carbonate, etc. contained in geothermal saturated

G

TurbineSolar thermal energy, waste heat fromhydrogen systems, etc. could also be
utilized as external heat sources

Biomass

150℃

Biomass power generation

Conducting a small-scaleveriﬁcation test to conﬁrm therisk of pipe blockage due toscale adhesion

Biomass

400℃
Steam
superheater

steam. As such, we performed a veriﬁcation test using an actual-scale superheater pipe at Takigami geothermal

Turbinepower plant where there is a high amount of silica (Fig. 2), and conﬁrmed that problems relating to scale adhesion

Gand corrosion did not occur during steam superheating test, thus clarifying that this system could be realized using
current technologies.
TurbineThere are a total of 27
locations across Japan with
abundant geothermal
resources at a temperatureof 150℃ or higher (●)

Furthermore, there are a total of
13 locations across Japan with
abundant biomass reserves(5,000DW-t/year or more) (●)
Prospective locations for
introducing hybrid systems

Fig. 1

34

Central Research Institute of Electric Power Industry

P

Injection wellHybrid power generation system

Conceptual diagram of a hybrid power generation system utilizing geothermal energy and biomass

Potential

Large

Application Examples of Research Results
CRIEPI is contributing to the further popularization of geothermal power generation in Japan through liaising with geothermal power companies,
etc. and promoting the introduction of hybrid heat source power generation systems combining geothermal energy and biomass.

Small

Biomass procurement potential*NEDO homepage

Prospective locations for introducing
hybrid power generation systems

FY2017 Annual Report

Production well

Single ﬂash geothermal
Geothermal
power generation
reservoir

Overlay analysis

Geothermal resource
potential (150℃ or higher)*Report issued by the Ministryof the EnvironmentG

Fig. 2 Small-scale veriﬁcation test
using an actual-size superheating
pipe (Kyushu/Takigami geothermal
powe plant)

References: Nakao et al., GRC Transactions, Vol. 41, p. 794 (2017)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

35

Renewable Energy

Energy Platform Creation Sector, Energy Engineering Research Laboratorymore) combining geothermal energy and biomass as an external heat source. By tentatively calculating the power

2–2.

2–2.

Major Research Results-11

Major Research Results–11

Development of an Accurate Demand and Supply Simulation
Model with the Aim of Future Balancing and Frequency Control
Aiming for low-cost and stable operation and control of power systems after

Electric Power
Transmission andDistribution

the establishment of a balancing market

Background
Japan’s current balancing and frequency control is performed by transmission and distribution system operators
using control reserves procured through public tenders however, under the Electricity System Reform, with the aimof procuring and operating control reserves more eﬃciently and economically, a balancing market is planning to beestablished by the year 2021. This is anticipated to have the eﬀect of reducing balancing and frequency control cost
due to the realization cross-border balancing control. Meanwhile, for stable operation and control of power systems,
it is necessary to design the scheme with consideration to the technical challenges. In order to realize low-cost andLoad Frequency
Control (LFC)

Economic Dispatching
Control (EDC)
Controls generator output
within the certain limits
and maintain a balance
between supply anddemand with less fuelcost.

Merit Order (MO)Here, merit order refers to
the energy price arranged
in order from least to
most expensive.

Outline of Results◇ Development of an accurate demand and supply simulation model
CRIEPI developed a demand and supply plan model and an automatic generation control model simulating
precisely generation dynamic behavior, the centralized automatic generation control function, etc. in an actual
power system. Through simulations utilizing these models, CRIEPI elucidated the technical challenges and cost
reduction beneﬁts due to the establishing balancing market in relation to load frequency control (LFC) andeconomic dispatching control (EDC).

activation scheme). Here, CRIEPI quantitatively indicated that by performing LFC based on MO that also considers
the ramp rate of generator output, the operating cost of SCR can be reduced while keeping the AR around the same

◇ Evaluated operating cost of tertiary control reserve based on cross-border balancing
By performing a 2-area cross-border balancing simulation targeting tertiary control reserve (TCR), we obtained(Fig. 2).

100
80
60
40

133.8MW

152.7MW100.0%

95.3%

240
200

134.5MW
96.8%

160
120
80
40

20
0

Current(pro-rata)

MO considering
energyprice only

AR 95.45 percentile＊[MW]Secondary control reserve
energy price[% yen/kWh]120

Secondary control reserve
energy priceAR

MO alsoconsidering
ramp rate

0

100
80

240
200
160

130.5MW

132.8MW60

128.8MW

129.9MW120

40

100.0% 100.0%

99.4% 87.6%

80

20
0

40
Balancing in eachcontrol area

Cross-borderbalancing

0

Fig. 1 LFC simulation results

Fig. 2 Results of a cross-border balancing simulation

For the current LFC, SCR is activated based on the ramp
rate pro-rata scheme. Meanwhile, in the case of MO-based
LFC, SCR is activated sequentially starting from the lowest
kWh unit price.

By utilizing low-cost tertiary control reserve in a wide area
(Area A + Area B), the energy price of the activatedtertiary control reserve is reduced. Moreover, theactivated volume of the tertiary control reserve is reduced
by imbalance netting.

＊ Percentile：The relevant percent when data is arranged in orderfrom smallest to largest.

36

120

Tertiary control reserve energy price
Activated volume of tertiary control reserve
AR (Area A)
AR (Area B)

AR 95.45 percentile[ MW]changing tie-line power ﬂow reference and both the operating cost and activation volume of TCR were reduced

Tertiary control reserve energy price[% yen/kWh]/activated volume oftertiary control reserve[％kWh]

Here, tertiary control
reserve is utilized by EDC
and can provide the fulloﬀered bid volume at thelatest 15-minute after its
activation.

Supports the realization of low-cost and stable operation and control of power systems through utilizing simulations.

level as it is currently, therefore low-cost and stable supply is possible (Fig. 1).

Here, secondary control
reserve is utilized by LFC
and can provide the fulloﬀered bid volume at thelatest 5-minute after its
activation.

Tertiary Control
Reserve

System Engineering Research Laboratory

cost (energy price) of SCR decreases, the area requirement (AR) increases compared to the current level (pro-rata

results which showed that, compared to balancing in each control area, there was hardly no increase in AR due to

The diﬀerence between
the load demand andpower supply within eachcontrol area.

Electric Power System Sector,

When secondary control reserves (SCRs) for LFC were activated based on merit order (MO), although the operating

Secondary Control
Reserve

Area Requirement (AR)Keita Tokumitsu / Yuji Hanai◇ Identiﬁed the technical challenges of load frequency control (LFC) based on merit order andevaluating the operating cost thereofCentral Research Institute of Electric Power Industry

FY2017 Annual Report

Area gross demand
forecast

The conﬁguration of
the simulation model

Operation modeof generators

Generator output
outside of simulation

Amount of procured
control reserves

Tie-line power ﬂow
reference

Automatic generation
control model

Demand and supply plan model
Generator data (output upper/
lower limit, etc.)

Various constraints(amount of control reserve
procurement, etc.)

Area grossdemandDemand andsupply plan

Generator output
AR
Activation volume
of control reserves
Balancing cost

Generator output
outside of simulation

Tie-line power
ﬂow reference

600
400
AR [ MW ]In order to maintain abalance between supply
and demand within eachcontrol area as well as thesystem frequency within
the synchronous area,
control generator output
based on secondary
control reserves that areunder automatic control.

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

accompanying the establishment of a balancing market and studied countermeasures thereof.

Major Research Results

Major Research Results

stable operation and control of power systems in the future, CRIEPI has identiﬁed the technical challenges

Measurement
Simulation

200
0
-200
-400
-600
0：00

6：00

12：00
Time

18：00

0：00

Overview of simulation using the power generation plan model and supply/demand control model

Application Examples of Research Results
In regards to the establishment of a balancing market by around the year 2021, the Japanese government, Organization for Cross-regional
Coordination of Transmission Operators, etc. can leverage these research results when designing the scheme, therefore a low-cost and stable
operation and control of power systems are anticipated after the balancing market is established.

References： Tokumitsu et al., CRIEPI Research Report R17006 (2018)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

37

2–2.

2–2.

Major Research Results-12

Major Research Results–12

Development of Image Processing Technology and an AI
Technique to Support the Maintenance of Transmission Towers
Contributing to labor-saving in transmission tower maintenance with a simple

Electric Power
Transmission andDistribution

deterioration judgment support tool

Background
Electric power companies apply anti-corrosive agent to transmission towers with advanced corrosion as a measure
to alleviate the eﬀects of tower aging. This means that, out of a vast number of transmission towers (average of
24,000 towers per electric power company) there is a need to identify those which require application ofanti-corrosive agent and eﬃciently determine an order of priority. However, often the extent of corrosion is ranked
through visual judgment based on photos of tower steel, therefore there is the issue of not only extensive labor but
also allocation of priority depended on an subjective evaluation. With the aim of achieving labor-saving intransmission tower maintenance, CRIEPI has combined image processing technology and an AI technique to

Major Research Results

photographs taken from helicopters, etc. and support the determination of an order of priority for anti-corrosive
agent application.

Outline of Results◇ Extraction of transmission tower portion from aerial photos and determination of deterioration ranking

Electric Power Transmission and Distribution

The extent to which corrosion has progressed is judged from photographs of transmission tower steel, however all
3D Structure Model
A 3D skeleton diagramused to investigate thestrength of a transmission
tower relative to its load.
Created from structural
drawings (blueprints) oftransmission towers.

other portions of such photographs are not required as they merely create noise. CRIEPI has developed an image
processing technology to extract only the transmission tower portion through comparison of a transmission tower
aerial photo and 3D structural model (Fig. 1). At the same time, we have also developed an AI technique todetermine the corrosion progression ranking for each portion of the tower based on the extracted transmission

Ryuichi Ishino

tower image. Through an overall assessment of corrosion progression rankings based on this AI technique, it is

Digital Transformation Unit, Energy Innovation Center

possible to judge the deterioration ranking of a transmission tower and easily allocate an order of priority for
anti-corrosive agent application based on the judgment results.

◇ A prototype of the support tool for judging ranking of transmission tower deterioration

Based on an image processing technology and AI technique, engages in the development of a support tool helping to save labor in themaintenance of transmission towers.

Based on the abovementioned image processing technology and AI technique, CRIEPI developed a prototype of thesimple deterioration judgment support tool. Using this tool and aerial photographs of two actual transmission

Judgment of corrosion ranking basedon an AI technique

towers, we veriﬁed the entire process of transmission tower extraction, corrosion progression ranking judgment andtower deterioration ranking judgment. Moreover, as a result of removing the portions with 20 ╳ 20 pixels from theCorrosion ranking frequency

Electric Power Transmission and Distribution

Major Research Results

develop a technology capable of automatically judging the deterioration ranking of transmission towers from aerial

two transmission tower extracted photographs (approximately 1,900) and judging the respective corrosion rankings
across ﬁve ranks, we conﬁrmed an accuracy rate of around 83%. Moving forward, we will investigate the practicallevel for judgment accuracy, further raise accuracy and create a tool to support the judgment of deterioration.

Comparison

Overlapping

Extraction

Judgment of transmission tower
deterioration ranking (set by each company)

1

2

3

4

Corrosion ranking 3
Corrosion ranking 4△％

Deterioration ranking□％

A

Corrosion ranking 3
Corrosion ranking 4

▲％

B

■％

5

・・・

Corrosion ranking based on a color sample
Extracted tower

Judging deterioration rank in order to determine the order of priority for applying anti-corrosive agent to transmission towers

Application Examples of Research Results
Using the results of this research, it is possible to signiﬁcantly reduce the labor required to judge the necessity for anti-corrosive agent application
performed by electric power companies on transmission towers. Moreover, whereas previously individual workers determined the order of priority
for application work based on their subjective judgment, the support tool developed by CRIEPI enables objective and rational determination, thus
Aerial photo

3D structural model

Overlapping result

Tower extraction(background removed)

increasing the ability to explain the decision behind whether to apply anti-corrosive agent or not.

Fig. 1 Extraction of a tower image using image processing technology
The round circles in the above ﬁgure are the points that were speciﬁed for theoverlapping of the aerial photo and 3D structural model

38

Central Research Institute of Electric Power Industry

FY2017 Annual Report

References： Ishino et al., CRIEPI Research Report C17013 (2018)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

39

2–2.

2–2.

Major Research Results-13

Major Research Results–13

Development of a Technology to Remotely Measure
the Salt Density of Insulator Surfaces using a Laser
Contributing to higher eﬃciency and speed in transmission tower

Background

Brush-Wipe Method

Insulators are essential for retaining insulation in electric power transmission and distribution equipment, however

A method to measure thesalt density of insulator
surfaces by washing thesurfaces using a brush,etc. containing distilledwater then measuring theelectrical resistance of thewater.

are susceptible to salt deposit due to being located outdoors and this can lead to transmission accidents stemmingfrom a reduction in insulation performance as a result of high salt density. As such, measuring the salt density of
insulator surfaces is important in preventing transmission accidents. Currently, salt density is measured manuallyusing a brush-wipe method, etc. With the aim of signiﬁcantly reducing the time required to perform measurementtasks, CRIEPI is engaging in research of Laser-Induced Breakdown Spectroscopy (LIBS), which enables
measurement to be performed remotely.

Laser-Induced
Breakdown
Spectroscopy (LIBS)

Steel brackets used tomount insulators, etc.

Contamination
classiﬁcation forsalt damage
The pollution of insulators is
categorized into multiple
levels depending on the salt
deposit density and theselevels are called
contamination classiﬁcation.
In regards to powertransmission facilities,
excluding cases of direct
exposure to seawater spray,
the contamination
classiﬁcation of A (0.038
mg/cm2) to D (0.55 mg/cm2)
are used as the maximum
speculated salt deposit
densities.

◇ Remote measurement of salt density with a distance of 20 meters
In order to apply LIBS to the insulators mounted to transmission towers, we performed remote measurements with adistance of 20 m, which is equivalent to the standard cross arm height of 66 kV transmission towers. In thisexperiment, we irradiated a ﬂat sample to which salt had intentionally been deposited with a laser beam andelucidated how the emission intensities of sodium (Na) and chlorine (CI), the main ingredients of salt, are related to

Takashi Fujii

salt density using emission analysis. From this relationship, it is possible to ﬁnd salt density based on emission
intensity. Conventionally, emission intensities of so called“sodium D lines”were primarily used, however CRIEPI

Applied High Energy Physics Sector,

adopted diﬀerent sodium and chlorine lines to measure wide concentration ranges up to high densities. As a result, weElectric Power Engineering Research Laboratory

demonstrated that it was possible to measure salt densities ranging from 0.009 to 0.7 mg/cm2, which covers almost all
contamination levels in Japanese contamination classiﬁcation for salt damage of power transmission facilities.

Engages in the development of laser-based remote/non-contact diagnosis technology for electric power equipment.

◇ Salt density distribution measurement for insulators
Actual insulators are not ﬂat, rather have a complex shape, therefore the salt density distribution is not always

Insulators

uniform. Uneven distribution may lead to formation of local conduction paths. As such, we performed a qualitative
salt density distribution measurement on insulators as a preliminary experiment. For the sample, we assumed theemission intensity would be high at the tip of the rib due to salt water concentrating and drying here as the insulator
was dipped in salt water, then left to dry in a position where the side with the rib was facing downwards.
Experimental results followed our above assumption, and we showed the potential to identify salt density by local
concentration level (Fig. 1).

C
D

D
E

E

C
F

F

B

B

A

(2)

G

G

A

(8)

ABCDEFG

(1)

C

F
E
D
C

D

(4)

B

B

E
A

A

F

1.0
0.8
0.6

Brush-wipe method
er

Las

eam

er b

Las

Tel

e

scop

Tele

Optical ﬁber

Spectrometer

eld

eﬁ

op
esc

of

Emissions of
sodium,w
vie chlorine, etc.

Emission spectrum
Used conventionally Used this time
Sodium
Sodium
D line589.00nm 819.48nm
Chlorine
589.59nm
837.59nm

power conversion equipment such as transmission towers. Moreover, LIBS is able to simultaneously measure various substances therefore has thepotential to be applied to the evaluation of insulator pollution due to various salt types, such as volcanic ash or factory ﬂue gas.
G PeakLIBS measurement locations

F Dip

E PeakD Dip

C Peak(Outer periphery)(Inner periphery)

Reference： Fujii et al., CRIEPI Research Report H17007 (2018)
CRIEPI TOPICS Vol. 25 (2018)

Fig. 1 Example of a qualitative salt density distribution measurement on the rib side of an insulator

40

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Wavelength

The technology developed through this research is anticipated to realize the swift measurement of salt density on the surfaces of insulators used in

0.2
0.0

In contrast to the brush-wipe method, whereby
analysis is performed primarily after retrieving theinsulators installed for monitoring purposes, the LIBS
method enables remote measurement from theground, therefore the insulators can be measured
swiftly on the spot with no need for retrieval.
Moreover, LIBS also enables charged insulators to
be measured safely without the need to gain close
proximity to live wires.

Row ofinsulators

Application Examples of Research Results

0.4

B Dip

(5)

Measurement locations on the
rib side of ceramic insulator※The Y axis shows the relative values in the case that A is 1.0

A Peak

GFEDCBA(6)(3)
GFEDCBAGGABCDEFG(7)

1.2

Conceptual diagram of salt density measurement for
insulator surfaces using LIBS

Emission intensity

Cross Arm

Outline of Results

Mean CI emission intensities from (1) to (8)A technology to identify
and quantify elements
deposited on or containedin the target by focusing
laser beams on the target
to generate plasma, thendiﬀracting the light emitted
from the said plasma.

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

maintenance/inspection work through remote measurement from the ground

Major Research Results

Major Research Results

Electric Power
Transmission andDistribution

Central Research Institute of Electric Power Industry

FY2017 Annual Report

41

2–2.

2–2.

Major Research Results-14

Major Research Results–14

Establishment of a Test Method for Evaluating the
Immunity of Drones in Electromagnetic Environments
Contributing to the safe utilization of drones for maintenance and inspection

Electric Power
Transmission andDistribution

work on overhead transmission lines, etc.

BackgroundIn recent years there has been an increasing amount of interest in the industrial utilization of drones. Even in theelectricity business, there are expectations of drones being utilized for the maintenance and inspection of overheadtransmission lines, which would otherwise require work-at-heights, the conﬁrmation of situations in hazardous

Ability of an electrical device
to withstand exposure toelectronic stress (electric
ﬁeld, magnetic ﬁeld, etc.)

overhead transmission lines, there is a need to clarify the impact of the electric or magnetic ﬁelds emitted from suchcontrol these sensors and motors, therefore when using such drones in close proximity to power equipment such as
power equipment on the drone. CRIEPI is engaging in research to evaluate the tolerance of drones inelectromagnetic environments (electromagnetic immunity).

Outline of Results◇ Establishment of an electromagnetic immunity evaluation test method
Commercial
Frequency (no.)

As the electromagnetic ﬁelds for evaluation of electromagnetic immunity, we selected three types; namely aThis is the frequency ofthe commercial powersource, and is either 50
Hz or 60 Hz in Japan.

spark discharge. We then conceived evaluation methods for the impact of these electromagnetic ﬁelds, respectively.

Spark Discharge

the aim of supporting utilization of drones in the maintenance and inspection of overhead transmission lines, we will

Gas electrical discharge
accompanied by a large
noise and spark. It isextremely rare for spark
discharge to occur on
power facilities however
the electromagnetic ﬁeld
generated by a spark
discharge includes several
GHz bands used incommunication, therefore
there is concern thiswould impact thewireless communication
used by drones.

commercial frequency electric ﬁeld, a commercial frequency magnetic ﬁeld and an electromagnetic ﬁeld caused byMoreover, utilizing the high-voltage facility at CRIEPI’s Shiobara Testing Yard. we built an evaluation device able toaccommodate super-high-voltage power transmission up to 500 kV, the highest voltage class in Japan (Table 1).
This has made it possible to quantitatively evaluate the electromagnetic immunity of drones. Moving forward, withaccumulate data and better clarify drone immunity level.

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

sensors such as GPS and speed sensors, as well as the electronic circuits and wireless communication equipment to

Major Research Results

Major Research Results

regions during disasters, conﬁrmation of equipment status, etc. Recently, drones are equipped with numerous
Electromagnetic
Immunity

Kiyotomi Miyajima

Lightning and Electromagnetic Environment Sector,
Electric Power Engineering Research Laboratory

Evaluates the impact of electromagnetic ﬁelds generated from overhead transmission lines and other power facilities on drones.

Table 1 Evaluate test method for drone electromagnetic immunity
TargetCommercial frequency
electric ﬁeld

Commercial frequency
magnetic ﬁeld

Electromagnetic ﬁeld causedby spark discharge

Content

Exposure to the electric ﬁeld
recreating a state in close
proximity to a transmission line

Exposure to the magnetic ﬁeld
generated from a large coil

Exposure to the electromagnetic
ﬁeld caused by spark discharge

1. Gradually move the drone closer
to the charged transmission line

1. Have the drone hover at the coilcenter and gradually increasemagnetic ﬂux density

1. Gradually move the drone closer
to the electric discharge gap of
the charged transmission line

2. Record the magnetic ﬂux
density where abnormalities
were observed in the drone

2. Record the information whereabnormalities were observed in
the drone (intensity of electric
discharge, etc.)

MethodEquipment
schematic

2. Record the electric ﬁeld
intensity where abnormalities
were observed in the drone

e
n lin

ssio

smi

tran

Vertical
proximity
Drone

Coil (forgenerating ahorizontal
magnetic ﬁeld)

d)

(c

ge
har

Hovering

GroundCoil (forgenerating a
vertical magnetic ﬁeld)

ed)

arg

(ch

ssio
smi
Spherical electrode
Spark
Electric discharge gap
discharge
Horizontal
Spherical electrode proximity
tran

Horizontal
proximityen lin

Aluminum sheet
GroundCoilExample of evaluation test for drone
horizontal magnetic ﬁeld immunity

Drone

The coil is suspended vertically relative
to the ground and the magnetic ﬂux
density is varied by changing theelectric current put through the coil. By
doing this, it is possible to evaluate theimmunity against the horizontal
magnetic ﬁeld of a drone hovering at
the coil center.

Application Examples of Research Results
Contributing to establishment of guidelines for selection of drones suitable for the maintenance and inspection of overhead transmission lines andother power facilities, as well as the revision of national guidelines, regulations, etc. foreseeable in the future.

GroundReference： Miyajima et al., CRIEPI Research Report H17010 (2018)

42

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

43

2–2.

2–2.

Major Research Results-15

Major Research Results–15

Elucidation of the Cable Surf-Riding Phenomenon ofUnderground Power Cables
Contributing to the soundness diagnosis and optimization of maintenance standards

Electric Power
Transmission andDistribution

for the increasing number of aged underground power transmission facilities

Background
When the surf-riding phenomenon occurs on underground power

A phenomenon whereby
the power cables inside apipeline buried underroads move primarily in the
direction of vehicle travel
due to the passing ofvehicles on the road.

travel (Fig. 1) and countermeasures must be implemented for thisDirection ofvehicle travel

cables, the cable primarily moves in the direction of vehicle
due to concern it will have the cause of cable buckling or

reducing the insulation performance of the cable junctions. To Directionof cabledate, several techniques for forecasting or combating this movement
surf-riding phenomenon have been proposed however these haveall been experimental with limited scopes of application ormechanism. Therefore, there is a need to establish a

Pipeline

Cable

minimally eﬀective due to using countermeasures where themovement of cables is forcefully restrained without clarifying theDeﬂection

Major Research Results

Major Research Results

Surf-riding
Phenomenon

Fig. 1 Conceptual diagram of
the cable surf-riding phenomenon

highly-versatile evaluation method and more eﬀective
countermeasure based on the mechanism of the surf-riding

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

phenomenon.

Outline of Results
Taiki Yoshida / Kunihiko Nakamura◇ Development of a model test apparatus for recreating the surf-riding phenomenon
We developed a small model test apparatus of around one-tenth of actual size in order to simulate the surf-riding
phenomenon of power cables (Fig. 2). In this apparatus, a PVC pipe assuming an underground pipe line is buried
and a tire is run along the road surface whilst controlling overburden load and the cable moves inside the PVC pipe.
Using this apparatus, various installation environments can be reﬂected, such as the road traﬃc environment (traﬃcEarthquake Engineering Sector, Civil Engineering Research Laboratory
Cable surf-riding test facility
Able to recreate the surf-riding phenomenon occurring on underground cables in various installation environments.

volume, vehicle weight, speed, etc.) and ground conditions.

Applyoverburden
stress using
air pressure

Start position

2000 mm
Model tire travel direction

Stop position

Model tire
Asphalt
Crushed rockToyoura sandMeasurement of displacement of
PVC pipe
cable ends using a non-contact type
(O.D. 26 mm, I.D. 20 mm)
displacement meter・・Strain gauge
Model cable
・・Horizontal/vertical accelerometer(approx. 1.6 m in length)

Fig. 2 Small model test apparatus (approx. 1/10 scale)

Mock tire used to run overt h e r oa d s u r f a c e i n t h esmall, indoor mock-up
testing facility

Application Examples of Research Results
By using the evaluation model proposed by CRIEPI, it is possible to easily judge whether or not countermeasures to alleviate cable surf-riding are◇ Development of a surf-riding phenomenon evaluation model

necessary in the design phase. Moreover, it is possible to select a more suitable countermeasure for existing cables on which the surf-riding

CRIEPI developed an evaluation model that taking account of most of the factors relating to the surf-riding

post-event countermeasures, more rational investment plans can be established as it is possible to conduct prior investigations into

phenomenon. Moreover, through a sensitivity analysis using the evaluation model, we indicated that the main
factors causing surf-riding phenomenon are the friction between the pipeline and cable, and the vertical/horizontal
vibration of the pipeline. As a result, we clariﬁed that partial installation of high-friction material around cables andthe use of anti-vibration rubber are promising as countermeasures with greater eﬀectiveness.

44

Central Research Institute of Electric Power Industry

FY2017 Annual Reportphenomenon is occurring by considering the unique installation environments and cable property values. Through these, compared to previous
countermeasures optimal for the actual circumstances.
References: Yoshida et al., CRIEPI Research Report N17014 (2018)
Nakamura et al., CRIEPI Research Report N16014 (2017)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

45

2–2.

2–2.

Major Research Results-16

Major Research Results–16

Establishment of a Security Testbed Targeting Power Grid
Control Systems and Substation Automation Systems
Helping to improve the response capability to cyber-attacks targeting power

Electric Power
Transmission andDistribution
IEC 61850

In recent years, the power grid control systems overseas applying the international standard of IEC 61850 are being
subjected to cyber-attacks in addition to situations triggering large-scale power outages. Even in Japan, in order toachieve low-cost and interoperability between diﬀerent vendors, monitoring and control devices complying with IEC
61850 are under development. In order to test the eﬀectiveness of security countermeasures and the feasibility ofcyber-attacks similar to those occurring overseas, as well as implement incident response drills for personnel
working with control systems, there is a need to establish a security testbed which is both low cost and features thenecessary functions.

Incident
In general“incident”refers
to happenings, events andaccidents. In the context
of information security,
incident refers to events
threatening a computer or
network’s security.

Intelligent Electronic
Device (IED)
A general-purpose device
with protection, control
and measurement functions
that is programmable andtherefore able to ﬂexibly
respond to various needs.

Station Bus
A network for use within
substations adopting IP
transmission to achieve
connectivity of IEDs
between diﬀerent vendors.
Mainly communicates
operation commands,
electrical current/voltage
values, status information,
etc.

Outline of Results◇ Establishment of a cyber security testbed
CRIEPI established a security testbed within a substation comprising of intelligent electronic devices (IED), an
operator console (HMI), a telecontrol unit (TC) and a station bus required for communication between thesecomponents. This environment is capable of recreating control logic and communication stipulated by IEC 61850.

Noriyuki Ueda

◇ Implementation of a function to detect/block communication in accordance with the IEC 61850 standard

Communication Systems Sector,

CRIEPI implemented the station bus with a function to detect and block communication in accordance with IEC

System Engineering Research Laboratory

61850. By using this function, it is possible to simulate the communication failure, etc. caused by a cyber-attack
without modifying IED or HMI, and monitor the communication during such times. Moreover, this function can also
be utilized as a security countermeasure as it is possible to detect and block communication from unauthorized
terminals.

IEC 61850 control communication
detection/block function

Control oﬃce
SCADA
Wide-area network

FY2017 Results

HMI

unauthorized device

Circuit breaker
operation command

Circuit breaker
operation command

HMI

block

Main components of the security testbed
IED

IED

one network device

IED

Station bus

IED

HMI or TC

Detection

Substation
TC

Tests the impact of cyber-attacks on power grid control systems in a security testbed, as well as the eﬀectiveness of security measures.

：IP transmission：Non-IP transmission (metal cable)

Human Machine Interface (HMI): Operator console

simulatedcircuitbreaker,simulated
CT/VT

Application Examples of Research Results

Supervisory Control And Data Acquisition system (SCADA)
Intelligent Electronic Device (IED)

Process bus＊

Simulatedcircuit breaker

Telecontrol unit (TC)

Simulated
CT/VT

This testbed is independent of general networks therefore it is possible to execute cyber-attacks using foreseeable scenarios in addition to known

Current Transformer (CT)forms of cyber-attacks, and verify the impact of such cyber-attacks on power grid control systems as well as the eﬀectiveness of related security※TC, HMI, SCADA and IED are simulated using software and not actualfor utilities.

Voltage Transformer (VT)equipment. A portion of the IED uses actual equipment.

measures. Furthermore, by carrying out practical security exercises for various scenarios, CRIEPI is helping to improve incident response capability

Fig. Diagram of security testbed for a power network control system＊ Process bus：A communication network utilizing IP/Ethernet transmission in order to use less cables for control between the IED and main circuit
devices. Electrical current/voltage values, trip signal, status information, etc. are communicated.

References： Ueda, GS5-3,Proceedings of annual conference of Electronics, Information and Systems Society, IEEJ, 2017
Shimada, TC10-6, Proceedings of annual conference of Electronics, Information and Systems Society, IEEJ, 2015

46

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

47

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

Background

Major Research Results

Major Research Results

An international standard
relating to smart grids. The
original aim of this standard
was the standardization of
information exchange
between intelligent
electronic devices (IED) in a
substation.

grid control systems

2–2.

2–2.

Major Research Results-17

Major Research Results–17

Utilization of an AI Technique for a Maximum Demand
Alert Service
Assisting reduction of maximum demand based on demand forecasting

Customer
Services

30-minute Demand
Mean power consumption
in a 30-minute interval(calculated once every 30
minutes). The largest
30-minute demand withina month is deﬁned as the
maximum demand for thatmonth.

In many cases, corporations or public organizations consume electricity so as not to exceed contract demand, which
is determined by their maximum 30-minute demand recorded in the most recent 12-month periods. Thus, reductionof maximum peak demand is economically beneﬁcial for the consumers. CRIEPI developed an AI-based method toforecast 30 minute demand and a prototype of services for consumers where email alerts are sent when theforecasted demand exceeds a predeﬁned precaution level.

Outline of Results◇ A method to predict 30 minute demand
The proposed method predicts 30 minute demand from one hour to 24 hours ahead based on smart meter data andweather data from the Meteorological Agency. The predictions are based on a simple linear regression model which
describes the relationship between input data in the past and demand data in the future. CRIEPI developed amethod to search a combination of coeﬃcients for the regression model by applying an AI technique, which enables
to prevent large errors in maximum demand prediction using limited past data.

Linear Regression
In statistics, estimation ofa model (function) to
describe a relationshipbetween a variable thatshould be predicted(explained variable) andvariables that explain the
explained variable is called“regression analysis.”It isfurther speciﬁed as“linearr e g r e s s i o n ”i f a l i n e a rfunction is used for themodel. For the electricity
demand forecasting, theexplained variable is thedemand data in the future
and the explanatory
variables are the input
data in the past.

Regression Coeﬃcient
Coeﬃcients for regression
equation correspond to
gradient of the function fora linear regression
equation. The regression
coeﬃcients are determinedby minimizing sum of theerrors of past forecast
results in the simplest
method.

Customer Services

Customer Services

Usually a consumer ischarged a basic fee forelectricity proportional tothe contract demand(maximum 30 minutedemand value in the mostrecent 12 months). This
type of contracts areusually applied to highvoltage (over 6,000 V)
c o n s u m e r s l i k ebusiness-use buildings orcommercial facilities.

Major Research Results

Major Research Results

Contract demand

Background

Hidenori Komatsu◇ Alert service for exceedance of precaution level
CRIEPI investigated a framework for a service utilizing the 30 minute demand prediction. We devised an alert
service system to notify users by emails if the forecasted demand exceeds the precaution level. This system enables
users to prioritize which minimum oversights of actual exceedances of the precaution level or minimum false alerts.
Users can also choose“1-hour-ahead alert”that sends email alerts if the 1-hour-ahead forecasted demand exceeds

Osamu Kimura

Digital Transformation Unit,

Energy System Analysis Sector,

Energy Innovation Center

Socio-economic Research Center

Assisting consumer’s energy-saving activities utilizing an AI technique.

the precaution level, or“1-day-ahead alert”that sends email alerts using the 24-hours-ahead forecasted demand, orsomewhere between them. Using an actual data set, the forecasting accuracy how many exceedances of precaution
level the alerts covered was 74.8% for 1-hour-ahead forecast without an interval and 96.7% for 24 hours ahead
forecast with an interval (without distinguishing in which time of the day the demand exceeded the precaution
level).
An alert for the following day
Forecasted demand of the following
day will exceed the precaution level
Send an email alert regarding
the following day

1-hour-ahead forecasted demand
will exceed the precaution level
Send an email alert regarding
1-hour-ahead demand

DemandTomorrow, you might exceed your contract demand.
Please check appliances in use and consider energy-saving
measures so as not to exceed your contract demand.
Today’s maximum demand (actual): 85 kW
Today’s maximum demand (forecasted): 116 ‒ 124 kW

Input data

Conceptual diagram of email alerts

Precaution level

Smart
meter
data

・
・
・
・
・
・

4 weeks earlier

Application Examples of Research Results

30 minute intervals
Forecasts demand
from 1 to 24 hour
ahead

ActualActualtemperature sunshine
durationNow

1 hour later

24 hours later

CRIEPI is promoting activities for energy-saving and cost-saving by incorporating this alert service into our energy-saving advice report system forTime

SMEs that we previously developed.

Conceptual diagram of the alert service system

References： Komatsu et al., CRIEPI Research Report C17007 (2018)
Komatsu et al., CRIEPI Research Report Y15004 (2016)

48

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

49

2–2.

2–2.

Major Research Results-18

Major Research Results–18

Evaluation of the Biological Eﬀects of the Magnetic
Field Generated by Induction Heating (IH) Cookers
Aiming to improve understanding of health risks relating to IH cooker-generated

Environment

magnetic ﬁelds

Background

Intermediate
Frequency

Recently, there are an increasing number of electronic devices utilizing intermediate frequency magnetic ﬁelds such

The frequency band
between the low
frequency band (300 Hz
or less) and highfrequency band (10 MHz
or more).

scientiﬁcally elucidate the eﬀect of magnetic ﬁelds regarding the health risk to humans. In the research conducted

as IH cookers and wireless power transfer systems. In order to be able to use these devices safely, there is a need toaround the world to date, not enough biological evidence has been accumulated in regards to the health risks ofmagnetic ﬁelds. CRIEPI used cells and laboratory animals to evaluate the health risk of the magnetic ﬁeld generated
by IH cookers (IH magnetic ﬁeld) through conducting an exposure experiment, then conducted various evaluation
tests relating to health risks, such as the reproductive and developmental toxicity, and clariﬁed that the IH magnetic

Major Research Results

Major Research Resultsﬁeld had no adverse eﬀects. Furthermore, CRIEPI is continuing eﬀorts to elucidate the carcinogenicity of IH
magnetic ﬁelds, which is not as yet fully investigated.

Outline of Results◇ Exposure experiments of an intense magnetic ﬁeld at the heating frequency of an IH magnetic ﬁeld
In order to investigate the carcinogenicity of IH magnetic ﬁelds, we used 50 each of male and female genetically
modiﬁed mice susceptible to carcinogens. Each sex of these mice was equally divided into 2 groups: control andmagnetic ﬁeld-exposed groups. The control group would not be exposed to a magnetic ﬁeld, while the exposed

Environment

by CRIEPI’s magnetic ﬁeld exposure facility for animals, the world largest of its kind. The magnetic ﬁeld intensity forour experiment was set at 200 μT, one order of magnitude higher than the 27 μT stipulated in international
exposure guidelines. The exposure period was made six months, which is the period of time that cancer begins tooccur spontaneously and complies with international test guidelines on safety evaluation using this strain of mice.
As a result of histopathological evaluations of neoplastic lesions in the organs and tissue of the mice after the

Izumi Nishimura

Environment

group mice were exposed to a magnetic ﬁeld at the heating frequency of an IH cooker (20 kHz) that was generated

Biological Environment Sector, Environmental Science Research Laboratory
Laboratory animals magnetic ﬁeld exposure facility

A unit that exposes mice and other laboratory animals to high-intensity IH magnetic ﬁelds for a prolonged period of time to evaluate thebiological eﬀects of the magnetic ﬁelds.

experiment, there was no statistically signiﬁcant increase in the frequency of neoplastic lesions in each organ andtissue of the exposed mice compared with those of the control group of mice. Obtained results demonstrated that,
under the conditions used for this experiment, exposure to the magnetic ﬁeld was not carcinogenic in this mousemodel (Table 1).

Blind Test

CRIEPI conducted a series of animal/cell experiments complying with international testing guidelines applied to

A method of ensuring theobjectivity of data
analysis by masking theexposure conditions fromthe person analyzing thedata.

safety evaluations for pharmaceutical products, etc. Furthermore, for our animal experiments, we collaborated withaccreditation bodies adhering to the Good Laboratory Practice and performing histopathological examinations
under blinded magnetic ﬁeld exposure conditions, thus securing reliability of the results. We also veriﬁed the
reproducibility of results by duplicating the same experiment.

Table 1 Main 4 toxicity tests directly connected tohealth risk evaluation and the results thereof

50

Evaluation item (laboratory animal, etc.: biological endpoints)

Test result
No eﬀect

Toxicity
Acute toxicity (rats: body weight, hematological changes)
Sub-chronic toxicity (rats: histopathological changes)

No eﬀect

Genotoxicity
Mutagenicity, chromosomal abnormality (cells, microorganisms)

No eﬀect

Carcinogenesis (this research)
Tumorigenesis (genetically-modiﬁed mice, neoplastic lesions)

No eﬀect

FY2017 Annual Report

Magnetic pot/pan
IH
magnetic
ﬁeld

Rectiﬁer circuit

IH
magnetic
ﬁeld

Converts to direct current

Inverter circuit
Converting direct electric current to a
20-90 kHz heating frequency and its Induction-heating coilharmonic frequencies of intermediate
frequency electrical currents

Mechanism of an intermediate frequency magnetic ﬁeld (IH magnetic ﬁeld) being generated from an IH cooker

Reproductive and developmental toxicity
Preimplantation period (rats: infertility, miscarriage)
Organogenesis (rats: malformed and underweight fetuses)

Central Research Institute of Electric Power Industry

Commercial
power source◇ Conﬁrming reproducibility of results through a rigorous experimentation method complying withinternational testing guidelines

Electromagnetic induction createdby a magnetic ﬁeld induces aneddy current on the pot’s bottom
in order to heat the pot.

Application Examples of Research Results
The results obtained through CRIEPI’s research and others will be compiled in health risk evaluation documents, such as the Environmental HealthCriteria published by the World Health Organization, through public disclosure in international scientiﬁc journals, then reﬂected in the exposure
standards and regulatory values of each country. Within Japan, these research results have been disclosed via the website of the Japan EMF
Information Center, an organization which disseminates fair and neutral information, and is helping improve understanding regarding the healthThrough CRIEPI’s research, numerous
highly-reliable test results have been
produced regarding important healthrisk indicators.

risks of the magnetic ﬁelds associated with IH cookers and wireless power transfer systems for electric vehicles.
References: Nishimura et al., J. Appl. Toxicol., Vol. 36, p. 199 (2016)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

51

2–2.

2–2.

Major Research Results-19

Major Research Results–19

Development of a General-Purpose 3D Numerical Modelfor Thermal Discharge Diﬀusion and Cooling Water Intake
Contributing to realizing eﬃcient environmental assessments through provision

Environmentof a swift dispersion prediction technique.

Background

Environmental
Assessment

When performing environmental assessments for the new construction or replacement (rebuilding) of power plants,

A process of investigating,predicting and assessing
likely environmental impactsof large-scale development
projects, etc. in advance.

plants, thermal power plants, etc. on the coastal ocean. Depending on the circumstances, either a hydraulic model

there is a need to evaluate the impact of discharge of warm water used for cooling purposes in nuclear power
experiment or numerical simulation is used as the technique to predict diﬀusion of warm water discharge, however
due to the increased complexity of power plant location conditions in recent years, there is a need for evaluations
that also consider the impact of adjacent existing power plants and river waters, simultaneously. Moreover, there isa desire to further speed up the prediction and evaluation process in order to reduce both the time and cost for

Major Research Results

Major Research Results

environmental assessments. CRIEPI is engaging in the development of a general-purpose 3D numerical model
applicable to both thermal discharge diﬀusion prediction and recirculation evaluation that does not depend on thediﬀerences in cooling water intake methods, location conditions, etc.

Outline of Results

Curtain Wall

CRIEPI developed the 3D model that response to the various water intake methods, such as intake towers andA wall built on the front ofa water intake inlet so as
to take in low-temperaturebottom seawater and shut
out warm water close to
the surface.

curtain walls, as well as both the surface and submerged discharge methods. By using this model, it is also possible

Environment

Environment◇ Development of the 3D model capable of predicting the diﬀusion of thermal (warm/cold) water
discharge under various conditions

Norikazu Nakashiki

to make predictions regarding the impact of the adjacent power plant (cumulative) and recirculation (mixing into

River and Coastal Environment Sector,

intake water) of warm water discharge, which was not possible using the conventional surface 2D model. Moreover,Environmental Science Research Laboratory

because this model can predict not only the diﬀusion of warm water discharge but also that for cold water
discharge, it can also be used for environmental assessments of LNG bases with cold water discharge.

◇ Provision of a swift prediction technique as a substitute to model experimentHigh performance parallel computer

Utilized in calculations based on the 3D thermal discharge diﬀusion model.

CRIEPI conﬁrmed that the warm water discharge diﬀusion prediction results obtained using the 3D model had

Prediction target

equivalent accuracy to results obtained using the conventional hydraulic model experiment. This means it is
a combination of the hydraulic model experiment and numerical simulation. This technique can also be utilized
experimentation.

Submerged
outletCooling water
intakeRecirculation

Cold water
discharge

Surface outlet
Warm water discharge

Cooling water intake

Various intake type (curtain walls,
intake pipe, intake towers)

Recirculation

Eﬀect of fresh water

LNG base
River water

Warm water
discharge

Interaction between
adjacent plants

Hydraulic model experimentWarm water discharge(submerged drainage)

when studying speciﬁcations of water intake equipment in the design stage, which previously relied on model

Power
plant

Surface 2D model

Warm water discharge(surface drainage)

possible to swiftly predict the diﬀusion in locations with complicated geological features, which previously required

Power
plant

General-purpose 3D model

Comparison of the general-purpose
3D model, conventional surface 2Dmodel and Hydraulic modelexperiment(○: applicable ×: not applicable)

Cold water discharge
Impact of adjacent
power plant

Application Examples of Research Results
As a technique substituting the hydraulic model experiment, the 3D model can be applied to locations where prediction using numerical simulation
had proven diﬃcult to date, thus contributing to a reduction in the time and cost required for environment assessments, equipment design, etc.

Various outlet type(surface, submerged)

Prediction target of the general-purpose 3D model

References： Tsubono et al., Journal of Japan Society of Civil Engineers B1 (Hydraulic Engineering) Vol. 74, I_775 (2018)
Niida et al., Journal of Japan Society of Civil Engineers B1 (Hydraulic Engineering) Vol. 73, I_583 (2017)

52

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

53

2–2.

2–2.

Major Research Results -20

Major Research Results -20

Quantitative Analysis of the Role of Nuclear Power in
Energy Policy in Japan
Fostering concrete understanding of the importance of nuclear power on Japan’s
macro economy

BackgroundLong-term Energy
Supply and Demand
Outlook

The Long-term Energy Supply and Demand Outlook, published by the Ministry of Economy, Trade and Industry in July

The document stating theoutlook for future energy
supply and demand
configuration based upon
the policies stated in theStrategic Energy Plan.

out diﬃcult to deliver due to, for instance, delay in recommencement of nuclear power plant units. CRIEPI has assessed

2015, has established a target of nuclear power ratio between 20 to 22% of the overall power generation mix in 2030.
While proper maintenance and utilization of the nuclear power stock is indispensable to achieve this goal, it might turnthe impact if nuclear power generation does not reach the target ratio in Japan’s power mix.

Major Research Results

Outline of Results◇ Analysis of impact on GDP and industry
Total Industrial
Investment inReal Term

With its own macro-economic simulation model, CRIEPI analyzed the future economic situations based on the assumption

Amount of investment
adjusted with priceincreases/decreases.

decrease by approximately 2.5 trillion yen if the remaining 7% was compensated by LNG-ﬁred power, or by approximatelythat the 2030 nuclear power generation ratio was 15%, 7% below the published target, which was compensated either by
LNG-ﬁred power and by renewable energy. Through this analysis, we calculated that the real GDP in the year 2030 would
2.7 trillion yen if compensated by renewable energy (Fig. 1). Moreover, we also calculated that the cumulative decrease intotal industrial investment in real term by 2030, which, if LNG-ﬁred power was to compensate nuclear power, would be 2.3

Utility Management

Utility Management

Major Research Results

Utility
Management

trillion yen, of which 1.7 trillion yen decrease is attributed to the manufacturing sector speciﬁcally. Alternatively, if
renewable energy was to compensate nuclear power, the decrease would be 2.5 trillion yen for the whole industry, of

Sumio Hamagata

which 1.9 trillion yen decrease for the manufacturing sector (Fig. 2).

Utilities Policy and Economic Analysis Sector,
Socio-economic Research Center◇ Analysis of impact on household incomes
Proxy Indicator

As for the per capita GDP, which is a proxy indicator for income, CRIEPI simulated that, in 2030, the per capita GDP

A n in dic ato r use d a s asu bstitute if th e ta rget
i n d i c a to r i s d i ﬃ c u l t todirectly measure.

would decrease by approximately 21,000 yen and 23,000 yen if the 7% of total power mix was compensated for by

Disseminates quantitatively analyzed results regarding the roles of energy and environmental policies in Japan’s economy.

LNG-ﬁred power and renewable energy, respectively.

World economy (precondition)

World economic growth rate,
trends in prices/interest rate, etc.

Fossil fuel prices (crude oil, coal, gas)

0.5

Reduced imports

0.0
-0.5
-1.0
-2.0
-2.5
-3.0

Reducedconsumption

Reducedinvestment
Reducedexports
Increased
imports

Reducedinvestment

Decreasein real GDP

LNG compensation case

Reducedexports

Renewable energy
compensation caseFig. 1 Decrease in real GDP and the breakdown thereof
assuming the target ratio for nuclear power is notreached (for the year 2030)
Factors of a decrease in GDP are as follows: (1)increased imports in line with an increase in fossil fuelimports, (2) decreased consumption due to a decrease
in real income in line with increased prices, (3)decreased exports and decreased investment in line withweakened international competitiveness due to anincrease in prices.

-0.5
-1.0
-1.5
-2.0
-2.5
-3.0

Decrease in
manufacturingindustry investment(cumulative total)
1.7 trillion yen
Decrease in
non-manufacturingindustry investment(cumulative total)
0.6 trillion yen

LNG compensation case

Decrease in
manufacturingindustry investment(cumulative total)
1.9 trillion yen
Decrease in
non-manufacturingindustry investment(cumulative total)
0.6 trillion yen

Renewable energy
compensation caseFig. 2 Cumulative decrease in real investment andthe breakdown thereof assuming the target ratio for
nuclear power is not reached (for the year 2030)

By exchanging common variables between theInter-Energy Competition Model (left) and theMacroeconomic Model/Input-Output Model (right), it
is possible to obtain simulation results consistentamong the economy, industrial structure and energy
each other. One characteristic of this system is thatthe economic impact by individual industrial sector
can be shown. The red rectangle indicates the model
boundary used for the calculations described above.

Inter-Energy Competition Model
Final energy consumption,
Domestic energy price,
CO2 emissions

Macroeconomic Model (short/mid-long term)

Economic growth rate, production, domestic prices, wages

Input-Output Model
Industrial structure

Prefectural Population Model

Future population, no. of households

Region-1.5

Reducedconsumption

Structure of CRIEPI’s model system

0.0Japan-wide

Trillion yen

Trillion yen

Multi-regional Econometric/I-O Model

Economic growth by region, regional industrial structure

EnergyEconomyApplication Examples of Research Results
These research results were featured in the“Proposal for Future Energy Policy”published by the Japan Business Federation in November 2017and are also used in other media channels to help better understanding regarding the role of nuclear power generation.

References: Hamagata et al., CRIEPI Research Report Y17502 (2017)
Hamagata et al., CRIEPI Research Report Y12033 (2013)

54

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

55

2–2.

2–2.

Major Research Results–21

Major Research Results–21

Development of a Tool Analyzing the Operational
Characteristics of Smart Communities
Contributing to the visualization of the relationship between PV, storage

Common in theMultiple Fields

A social system based on anext-generation powertransmission/distribution
network (smart grid) within aﬁxed community scale which
controls customer-side
energy resources (renewableenergy, co-generation,
storage battery, demand
response, etc.) through anenergy management systemutilizing ICT and IoT toachieve total management ofenergy utilization in a region
as well as provide a newsocial service.

A broker who cooperates
with the eﬃcient operation ofenergy management throughbundling the power demandof multiple customers andcustomer-side energy
resources to establish acertain scale of demand
and/or supply capability.

The proactive involvement of the customer in eﬃcient production and utilization of energy is essential to therealization of smart communities. Various retail operators and aggregators utilizing customer-side energy resources
appear in the communities and VPP technology is used on a regular basis. If these communities adopt anautonomous operation approach that only values economic performance (cost minimization, etc.) there is a concern
that, if the demand ﬂuctuation in the power distribution system further increases, voltage ﬂuctuation will also
increase, leading to a deterioration of power quality and excessive current in power transmission/distribution lines,
etc. With the aim of achieving both rationalization of power transmission/distribution system operation and facility
construction, as well as the economic operation of smart communities, CRIEPI has developed a tool to analyze themutual eﬀect between communities and power distribution networks.

Outline of Results

Common in the Multiple Fields◇ Development of a mutual eﬀect analysis tool for smart communities and power distribution networks
By linking the community operation plan program (1) and power distribution system analysis program (2) alreadydeveloped by CRIEPI, we established a tool to analyze mutual eﬀect. This tool makes it easy to analyze the impactthat community autonomous operation has on the power quality of power distribution systems and, in the reverse,
the impact that limitations relating to power quality of power distribution systems has on community operational

Eitaro Omine / Hiroyuki Hatta

Distribution System Unit, Energy Innovation Centercharacteristics. This tool has a function to simulate demand response (DR) which aims for power demand duckA mechanism to make thecustomer-side energy
resources dispersed acrossvarious regions function as if
one power plant. Contributes
to the balancing of power
supply/demand as if alarge-scale power plant.

Duck Curve
Describes the trend whereby
real power demand (netpower demand obtained after
subtracting photovoltaic
power volume from the actual
power demand) drops largely
during the daytime andincreases in the evening. The
name“duck curve”comesfrom the fact that the power
demand curve over the courseof one day is shaped like a
duck (the stomach during theday, head during the evening).

curve improvement, load leveling, etc. (3), and is able to analyze the impact of DR. Moreover, community demanddata is necessary for analysis, therefore a function utilized in the analysis of power demand data in arbitrary regions

Supporting the practical operations of power transmission/distribution companies and community operators with a tool to analyze theoperational characteristics of smart communities.

prepared with CRIEPI’s existing demand simulation tool (4) and electric vehicle traﬃc simulator (5) was added tocreate a highly-practical tool.

Mutual eﬀect analysis tool for
smart communities and power
distribution networks

Inputs・Demand data
・Price information（electricity prices,
PV purchase price）
・Device capacity（PV, storage batteries, etc.）
・Power distribution line data
・Other(4) Demand simulation toolCalculates the power
demand per time of day
for the consumer groups
of arbitrary regions(5) Electric vehicle traﬃcsimulator
Simulates EV travel andcalculates the charging
power by location andtime of day(1) Community operation
plan program
Preparation of an operation
plan for the load/PV/battery,etc. of customers andcommunities(2) Power distribution systemanalysis program (CALDG)
Simulation of the voltage,current, etc. in a power
distribution system(3) DR command automatic
calculation program
Automatically calculates
DR command which aims
at power demand duck
curve improvement andload leveling

Output・Load, PV, storage battery power volumes（plan, control results）
・Voltage/current of power distribution
cable
・Cost（operator/customer）
・Other30

No PV, No BT
With PV, No BT
With PV, With BT

20
10
0

This is an example of analyzing a case whereby
the DR command suppressing charging of anelectric vehicle (EV) is executed at 9:00 and ended
at 12:00. This example assumes that the all EVs
can be connected to chargers when parked at theowner’s place of work, home, etc. Charging power
drops once from 9:00 onwards but then increases
sharply when DR ends at 12:00 and exceeded thepeak value without DR signal.

DR execution
time range

50

Peak charging
power value
without DR

40

Charging power increases
sharply when DR ends
Rapid charging ST

30

Other

20

Place of work

10
0

Home
0

3

6

9

12

15

18

21

Time
［o’clock］

Application Examples of Research Results

-10
-20

Example of an analysis using the developed tool

EV charging power［10,000 kW］

VPP

Community load power（MW）

Common in the Multiple Fields

Aggregator

Background

Major Research Results

Major Research Results

Smart Community

batteries, demand response and power quality

0

6

12

18

24

Time (o’clock)PV introduction volume：35 MW
Storage battery (BT) introduction volume：
30 MW，
60 MWhGraph output example

Overview of the mutual eﬀect analysis tool for smart communities and power distribution networks Inputs

The results of this research are contributing to the appropriation of facility formation in power distribution systems including smart communities,
such as the judgment regarding locations for installing voltage control equipment and streamlining of equipment carried out by powertransmission/distribution companies. The results of this research are also contributing to the optimization of the operation plans prepared bycommunity operators as well as cost-reduction and rationalization of voltage/current management tasks conducted by powertransmission/distribution companies when operating power distribution systems.
References: Hatta et al., CRIEPI Research Report C17010 (2018)

56

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

57

2–2.

2–2.

Major Research Results–22

Major Research Results–22

Development of an Evaluation Technology to Achieve
Long-Life Lithium-ion Batteries
Contributing to the long-term operation of rechargeable batteries suited to the

Background

Lithium-ion Battery(LiB)

Renewable energies, such as photovoltaic and wind power generations, are being introduced against global

A rechargeable battery thatcharges and discharges bytransferring lithium ions
between the positive andnegative electrodes.
Various materials are used
to make the electrodes,
however in many cases,
carbon (graphite) is used
for the negative electrodeand lithium cobalt oxide isused for the positiveelectrode. The separator issandwiched between
positive electrode andnegative electrode sheet,and multi-layers are piled
up and the entire battery isthen soaked in an organic
electrolyte solvent.

batteries (LiBs) are as one of procedures to achieve the stable system. Moreover, in the transportation sector, thewarming. To connect them to power grid systems, the destabilizing eﬀect on the systems is of concern. Lithium-ion
increase of electric vehicles (EV) is determined as one of the measures to achieve a low-carbon society, therefore itis predicted that the demand for rechargeable batteries will continue to rise. CRIEPI continues R&D of an
all-solid-state battery which can be used as stationary storage and also for EVs. We are also developing anevaluation technology to achieve long-life lithium-ion batteries.

Outline of Results◇ Development of an all-solid-state battery with further safety
Currently used LiBs have a risk of ﬁre incidents due to a ﬂammable organic solvent used inside them. In order toYo Kobayashi

safely operate the large-scale power storage systems expected in the future, CRIEPI is developing an all-solid-stateElectrochemical Sector,

battery made from ﬁre-retardant materials. Through the optimized design of a solid polymer electrolyte combinedwith the positive/negative electrode material of existing LiBs, we succeeded in developing a longer life battery thanMaterials Science Research Laboratory

existing LiBs. Furthermore, we started to develop a new battery consisting of only inorganic materials to improvesafety performance (nonﬂammability, etc.).

Promotes development of next-generation rechargeable batteries and engages in activities aimed at improving evaluation technology
of LiB material deterioration factors, battery life estimates, etc.

◇ Analysis and evaluation of various LiBs based on electrode material characteristics
SEM

LiBs started to be installed for stationary use. CRIEPI clariﬁed the respective elemental components and crystalline

Nistructures of the positive and negative electrodes in LiBs, and conducted a charging/discharging experiment on
half-cells (positive or negative electrode individually) to elucidate the relationship between the electrode materialand charge/discharge characteristics. Based on this result, we developed a technique to estimate the life
characteristic of LiBs with various combinations of positive and negative electrodes (Fig. 1).

10 m

Performance evaluation based on material
Life

Deterioration factors

Battery disassembly/electrode analysis

Cost

High capacity/
short life

Factor analysis

Capacity

Operational range divergence +reduced positive electrode capacity

Fig. 1 Scheme of battery deterioration characteristics through combinations of various electrode materials

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Analysis example of the positive electrode surface
in the LiB by electron microscopy

Application Examples of Research Results
By using the various LiB evaluation technologies, it is possible to select the suitable LiB for the stationary application and select the right battery tosuit running conditions and operations. Moreover, CRIEPI will push ahead with the development of a safer next-generation battery with the aim ofrealizing a large-scale storage battery for stationary use responding to future expansion of renewable energy.

Operational range divergence

Reduced positive electrodecapacity58

Co

Capacity

Multi-dimensional
non-destructive analysis

Performance
evaluation

Compact

CapacityHigh voltage - high capacity/ High capacity - long life/
short life
high cost - low voltage

Manufacturer speciﬁcations

Voltage

CapacityLong life/
low voltage

Voltage

Voltage

Capacity

Low cost - high capacity/
low voltage

Capacity

Voltage

CapacityHigh capacity/
high cost

Negative electrodecharacteristics

High voltage/
short life

Voltage

Capacity

Voltage

Battery characteristics

Low cost/
low voltage

Voltage

Positive electrodecharacteristics

Battery
characteristics

Voltage

Material
characteristics

Mn

References: Kobayashi et al., CRIEPI Research Report Q16001 (2017)
Yamazaki et al., CRIEPI Research Report Q16010 (2017)
Kobayashi et al., J. Power Sources, Vol. 341, p. 257 (2017)

Central Research Institute of Electric Power Industry

FY2017 Annual Report

59

Common in the Multiple Fields

Common in the Multiple Fields

stationary application through performance evaluations

Major Research Results

Major Research Results

Common in theMultiple Fields

Ⅱ．Financial Statement
1.

1.

Overview of Financial Statement

Overview of Financial Statement

Compared with the previous ﬁscal year, ordinary income fell by approximately 900 million yen due primarily to decreased business revenue
relating to consigned research, however ordinary expenses also fell approximately 200 million yen due primarily to a reduction in expenses suchas consumable goods expenses, therefore although there was a reduction in the change in ordinary proﬁt, a surplus of approximately 400 million
yen was achieved.

（1 mill yen）
Net Assets Variation Statement

Ordinary expenses
Labor costs
General running costs

Current ordinary proﬁt
Current general net
assets change

FY2016

Diﬀerence

29,57629,803

△226

9,909

9,735

174

19,667

20,068

△400

433

1,153

△719

3,640

2,842

798

FY2017FY2016

Diﬀerence

30,01030,956△945

25,38525,249

136

4,204

5,415

△1,211Other revenue

233

103

130

Transfer from designatednet assets

186

188

△1

Ordinary revenue
Ordinary beneﬁt received
Operating revenue

FY2016

Diﬀerence

Transfer to general net assets

186

188

△1

Current designated net
assets change

△78

△109

30

Current net assets change

3,561

2,732

829

25,000Transition ofordinary
revenue※

20,00015,000Subsidy etc. received

Diﬀerence

108

78

29

0

25,00020,000Current assets

5,659

4,546

1,113

10,0005,000

Current liabilities

FY2017FY2016

Diﬀerence

5,238

4,274

964

49,726

3,600

Fixed liabilities

9,357

9,170

187

Total assets

58,98654,272

4,713

Total liabilities

14,595

13,4441,151

026,27923,56523,56523,56525,24925,385

2009

2010

2011

2012

2013

2014

2015

2016

2017 （FY）

32,19531,50429,89429,286

28,61628,30029,803

20,274

18,982

17,571

18,23720,04918,831

20,06819,667

11,550

11,23010,912

11,715

10,37810,031

9,468

9,735

9,909

2009

2010

2011

2012

2013

2014

2015

2016

2017 （FY）

30,081

29,576

2,178

324

403

△78

General net assets

44,06640,425

3,640

Total net assets

44,39040,8283,561

Designated net assets

1,153

1,000

188

0

△1,000

△ 447

△ 943

△2,000△3,0002009

60,00050,000Transition of
overall assets

433

△678
△2,139△2,241

2013

2014

56,82855,86620162017 （FY）

2010

2011

2012

49,822

49,52850,64450,536

36,83637,35037,557

36,847

41,11238,752

38,09640,82844,390

2009

2010

2011

2012

2013

2014

2015

2016

2017 （FY）（1 mill yen）

Net assets

FY2017 Annual Report

Labor
costs

2,000

53,326

Central Research Institute of Electric Power Industry

27,273Generalrunning
costs 20,645

3,000

Fixed assets

60

27,377

15,000Liabilities
Diﬀerence

30,010（1 mill yen）

（Unit: 1 mill yen）

FY201630,956（1 mill yen）

Balance SheetFY2017

27,6215,000

Transition ofordinary
proﬁt※

Assets26,476

27,84010,000Transition ofordinary
expenses※
FY2016

28,83930,80430,000FY201730,082

Ordinary
beneﬁtsreceived

35,000Change in designated net assets
FY201730,561

30,000Change in general net assets
FY2017

34,37335,000（Unit: 1 mill yen）

2015

51,73954,27258,98640,00030,00020,000Net
assets

10,0000* From FY2016, loss on retirement of ﬁxed assets is included in ordinary expenses, therefore ﬁgures for the previous ﬁnancial year have beenrearranged accordingly.

Central Research Institute of Electric Power Industry

FY2017 Annual Report

61

2.

2.

Financial Statement
Balance Sheet

Statement of Changes in Net Assets
From April 1, 2017 to March 31, 2018

As of March 31, 2018

（Unit: 1,000yen）

Account

Current ﬁscal year

1. Current assets
Cash and deposit
Accounts receivable
Suspense payments
Advance payments
Total current assets
2. Fixed assets（1）Special assets
Buildings
Facilities attached to buildings
Structures
Machine and equipment
Tools and furnitureLump-sum depreciable assets
Intangible ﬁxed assets
Special assets for retirement lump sum grants beneﬁts package allowance
Speciﬁc assets for depreciation allowance
Special assets for acquisition of research facilities reserves
Special assets for special project reserves
Speciﬁc assets for base establishment allowance
Total special assets（2）Other ﬁxed assets
Land
Buildings
Facilities attached to buildings
Structures
Machine and equipment
Tools and furniture
Rolling stock and vehicles
Lump-sum depreciable assets
Intangible ﬁxed assets
Construction in progress accounts
Total other ﬁxed assets
Total ﬁxed assets
Total assets

Ⅱ Liabilities

1. Current liabilities
Accounts payable
Deposits received
Advances received
Accrued bonus
Total current liabilities
2. Fixed liabilities
Allowance for retirement beneﬁts for directors
Accrued retirement beneﬁts for employees
Total ﬁxed liabilities
Total liabilities

Ⅲ Net assets

1. Designated net assets
Special beneﬁts
Subsidies
Donations, etc.
Total designated net assets（including appropriation to special assets）
2. General net assets（including appropriation to special assets）
Total net assets
Total of liabilities and net assets

Central Research Institute of Electric Power Industry

Previous ﬁscal year

ChangeAccount

Current ﬁscal year

Previous ﬁscal year

（Unit: 1,000yen）

Change

ⅠGeneral net assets change

ⅠAssets

62

Financial Statement

FY2017 Annual Report

1.Ordinary proﬁt(1)Ordinary revenue[1] Beneﬁt received
Ordinary beneﬁt received[2] Operating revenue
Consigned research operating revenue
Other operating revenue[3] Other revenue[4] Transfer from designated net assets
Total ordinary revenue(2)Ordinary expenses[1] Operating expenses
Labor
Salary and beneﬁt
Retirement beneﬁt
WelfareGeneral expenses
Supplies and printed materials
Utilities
Outsourcing costs
Joint research contribution
Repair expenses
Rent
Taxes and dues
Travel and transport
Depreciation
Loss on｠retirement of ﬁxed assets
Other
Subtotal of operating expenses[2] Administrative expenses
Labor
Director remuneration
Salary and beneﬁts
Retirement beneﬁt
WelfareTransfer of allowance for director retirement beneﬁts
General expenses
Supplies and printed materials
Utilities
Outsourcing costs
Repair expenses
Rent
Taxes and dues
Travel and transport
Depreciation
Loss on｠retirement of ﬁxed assets
Other
Subtotal of administrative expenses
Total Ordinary expenses
Current ordinary proﬁt
2.Non-recurring change(1)Non-recurring proﬁt[1] Gain on sale of ﬁxed assets[2] Gain on donation of ﬁxed assets
Total non-recurring proﬁt(2)Non-recurring expenses[1] Business structural reform cost[2] Fixed asset impairment loss
Total non-recurring expenses
Current non-recurring change
Current general net assets change
General net assets beginning balance
General net assets ﬁnal balance

Ⅱ Designated net assets change[1] Subsidies received[2] Gain on donation of ﬁxed assets[3] Transfer to general net assets
Current designated net assets change
Designated net assets beginning balance
Designated net assets ﬁnal balance

Ⅲ Net assets ﬁnal balanceCentral Research Institute of Electric Power Industry

FY2017 Annual Report63Facts & Figures

Central Research Institute of Electric Power Industry

FY2017 Annual Report65Research Results / Intellectual Property

Research Reports / Research Papers / Intellectual Property

Research Network

This section introduces key data on CRIEPI’s FY2017 activities, including the number of report publications, number of paper
presentations and number of patent applications.

Fig. 1

Transition in number of reports published（No. of reports）

Research reports, etc.

600
500
400
300
200
100
0

Fig. 3

Consigned research report

515

498

436

453

166

183

256

281

270

270

259

217

2013

2014

2015

2016

501
222

Academic papers (peer reviewed)

1500

1000

1,409

1,049

1,312
1,412

1,062

971

1,449

1,092

Utility management 19
Environment 27

Thermal power
generation

89

Electric powertransmission anddistribution

Hydropower
generation

189

16

Fig. 4 Breakdown of no. of FY2017 papers by subject field

Common in the multiple ﬁelds

Other 129

16

1,295

971

Utility management 37
Nuclear power
generation

Environment 82

Swedish Nuclear Fuel and Waste Management Company (SKB)
Studsvik Nuclear AB
Korea Electrotechnology Research Institute (KERI)
Korea Electric Power Research Institute (KEPRI)
Oﬃce for Nuclear
Fortum Power and HeatRegulation
Korea Hydro and Nuclear Power Company Central
European Technology
Research Institute (KHNP-CRI)
Studiecentrum voor Kernenergies ‒ Centre
Development Ltd. (ETD)
Korea Atomic Energy Research Institute (KAERI)
d’etude de l’Energie Nucleaire (SCK・CEN)
Korea Institute of Nuclear Safety（KINS）
Gesellschaft für Anlagen- undSeoul National University of Science and Technology
Reaktorsicherheit mbH (GRS)
Korea University
Federal Institute for Materials
Research and Testing（BAM）
Jacobs University Bremen
United States Nuclear Regulatory
Taiwan Power ResearchCommission (NRC)
Institute（TPRI）
National Cooperative for the
Taiwan Power Company (TPC) Electric Power Research Institute (EPRI）
Disposal of Radioactive Waste (NAGRA)Southwest Research Institute (SwRI)
China Electric Power
National Center for Atmospheric
French Atomic Energy Commission (CEA)
Research Institute (CEPRI)
Research (NCAR)）
Électricité de France (EDF）
Battelle Memorial Institute (BMI)
National Agency for Radioactive Waste Management (ANDRA）
University of California, Santa Barbara (UCSB)
L’Institut de Radioprotection et de Sûreté Nucléaire (IRSN)
Texas Tech University
European Commission

419

Customer services 68

Organization for Economic Co-operation andDevelopment / Nuclear Energy Agency(OECD/NEA)

Electric power Thermal powertransmission and generation
distribution

5000Institute for Energy Technology (IFE)80

Customer services 40

In recent years, CRIEPI has been strengthening its collaborative relationships with Électricité de France (EDF) and the ElectricPower Research Institute (EPRI) in particular. In November 2017, through an annual meeting with EDF, we commenced a newresearch collaboration related to seismic motion. CRIEPI has made other eﬀorts to further deepen its interaction with both EDF
and EPRI, such as participating in a workshop hosted by EPRI in December aimed at building an international cooperative
framework for the reduction of uncertainties relating to the eﬀects of low-dose-rate radiation.

Main Partners for Research Cooperation Agreements and Joint Research

Nuclear power
generation

2017（FY）

Papers presented at academic conferences

1,339

Other 36

Common in the multiple ﬁelds 5279

Transition in no. of papers presented（No. of papers）

Fig. 2 Breakdown of no. of FY2017 reports by subject field

With the aims of identifying trends in forefront energy-related R&D as well as strengthening and enhancing research networks,
CRIEPI proactively promotes research cooperation agreements and engages in joint research with international partners
possessing high technical standards.

360

350

368

357

324

2013

2014

2015

2016

2017（FY）

Fig. 5 Breakdown of no. of FY2017 patent applications by subject field

161

366

Hydropower
generation

17

Commonwealth Scientiﬁc andIndustrial Research Organisation (CSIRO)
Participation in International Organizations
Union of the Electricity Industry (EURELECTRIC)
Association of the Electricity Supply Industry of East Asia andWestern Paciﬁc (AESIEAP)World Nuclear Association (WNA)
International Electric Research Exchange (IERE)Electromagnetic Transients Program-Development Coordination
Group (EMTP DCG) Committee

Fig. 6 Breakdown of no. of FY2017 patent registrations by subject field

Common in the multiple ﬁelds 2

Environment 1
Customer services 8

Nuclear power
generation

Main overseas institutions with whom CRIEPI has comprehensive cooperation agreements and the content thereofCommon in the multiple ﬁelds 69Environment
Electric powertransmission anddistribution

25

Customer services 1

Thermal power
generation

9

Electric powertransmission anddistribution

32

22

Partnerorganization

Nuclear power
generation

14

Thermal power
generation

8

Renewable energy 3

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Cooperation content

France’s largest electric
power company founded in
1946. Conducts in-house
R&D activities covering allelectric power businesssectors.

Cooperation agreement: Since 2012
(Main) Nuclear power generation (PRA, SA), power transmission andindustry infrastructure, next-generation grid, hydrogen, customer
side(Other) Nuclear power generation (maintenance/operation of power plants,
life management, spent fuel management), renewable energy,
power transmission infrastructure

Electric Power
Research
Institute(EPRI)

A nonproﬁt research
institution established in
Palo Alto, California, U.S.A.
in 1973.

Cooperation agreement: Since 1976
Nuclear reactor material, low-dose-rate radiation, nuclear power risks andsafety management, hydrochemistry/geothermal utilization, electric powertransmission and distribution and the utilization thereof

Southwest
Research
Institute(SwRI)

A nonproﬁt research
institution established in San
Antonio, Texas, U.S.A. in1947.

Cooperation agreement: Since 1997
Information exchange, personnel interaction and conducting of experiments
which CRIEPI cannot conduct due to Japanese regulations, etc.

Électricitéde France(EDF)

Hydropower generation 1

66

Overview of partnerorganization

Central Research Institute of Electric Power Industry

FY2017 Annual Report67Organization

Locations

Organization

CRIEPI facilities are located in Tokyo and four surrounding prefectures in the Kanto region. These facilities consist of four
research and business activities bases and two testing bases.
Currently, CRIEPI is developing its facilities with a focus on the Yokosuka Area and Abiko Area, and aims to make Yokosuka abase for research into energy and industrial technologies and Abiko a base for research into natural and environmental science.

Board ofCouncillors
Board ofDirectors
President

GeneralAuditor

Shiobara Testing Yard

Executive Vice
President★

Akagi Testing Center

Head Oﬃce

Internal Audit Oﬃce

General Aﬀairs Group

Planning GroupAccounting & Finance Group

Public Communications Group

Nuclear Power Plant
Maintenance Research Team

Nuclear Risk Research Center

Energy Innovation Center

Nuclear Technology Research Laboratory

Energy Engineering Research Laboratory

System Engineering Research Laboratory

Abiko Research Contracts & Intellectual Property Section

Yokosuka Research Contracts & Intellectual Property Section

Planning and Administrative Team

Risk Informed Decision Making Promotion Team

Risk Assessment Research Team

External Natural Event Research Team

Radiation Safety Research Center

High Power Testing Laboratory

PD Center

Shiobara Testing Yard

Materials Science Research Laboratory

Nuclear Fuel Cycle Backend Research Center

Electric Power Engineering Research Laboratory

Civil Engineering Research Laboratory

As of June 2018

★ Eight Research Laboratories

CRIEPI’s research division essentially consists of eight research laboratories, each specializing in a speciﬁc subject ﬁeld, with the aim ofstrengthening consistent research capability in each ﬁeld to cover everything from basic to applied research. In addition, by forming

Komae Area
Komae Operation & Service Center
2-11-1 Iwadokita, Komae-shi, Tokyo 201-8511

Environmental Science Research Laboratory

Civil Engineering Research Laboratory, Environmental Science Research Laboratory, AbikoOperation & Service Center, Procurement Center
1646 Abiko, Abiko-shi, Chiba 270-1194
TEL: +81-4-7182-1181

Socio-economic Research Center

Abiko Area

Akagi Testing Center

Energy Innovation Center, Nuclear Technology Research Laboratory, Energy Engineering ResearchLaboratory, System Engineering Research Laboratory, Electric Power Engineering ResearchLaboratory, Materials Science Research Laboratory, Yokosuka Operation & Service Center
2-6-1 Nagasaka, Yokosuka-shi, Kanagawa 240-0196
TEL: +81-46-856-2121

Safety Management Center

Yokosuka Area

Yokosuka Operation & Service Center

Internal Audit Oﬃce, Head Oﬃce, Nuclear Risk Research Center, Socio-economic Research Center
1-6-1 Otemachi, Chiyoda-ku, Tokyo 100-8126
TEL: +81-3-3201-6601

Abiko Operation & Service Center

Otemachi Area

Komae Operation & Service Center

Yokosuka Area

● Abiko Aria
﹇ Bases for natural and environmental﹈
science research●
YokosukaArea﹇ Bases for research into energy industry﹈
technologies

Otemachi Head Oﬃce

Komae Area

Procurement Center

Abiko Area

Research Laboratories and Centerscross-laboratory projects, CRIEPI conducts a matrix-type research framework able to respond ﬂexibly to the needs of the electrical power industry.

TEL: +81-3-3480-2111■ Nuclear Risk Research Center（ NRRC）
NRRC was established in October 2014 to contribute to voluntary eﬀorts and continuous improvement of nuclear power plant safety by electric
power companies. Through close liaison with business operators, the NRRC is promoting research into large-scale natural disasters and otherlow-frequency natural external events, probabilistic risk assessment (PRA), decision-making utilizing risk information, development of the latest risk
communication techniques and other R&D aimed at risk mitigation.

Akagi Testing Center
2567 Naegashima-machi, Maebashi-shi Gunma 371-0241

TEL: +81-27-283-2721▲ Energy Innovation Center（ ENIC）
ENIC was established in October 2016 with the aim of comprehensively and eﬃciently solving issues of both the electric power sales and power
distribution divisions and contributing to electric power business reform through utilization of IoT and AI. ENIC engages in research relating toadvancement of electric power supply-demand management and the digital transformation of the electric power business. It also strives to achieveswift solution proposals through the Technology Promotion Unit set up within ENIC.

Shiobara Testing Yard
1033 Sekiya, Nasushiobara-shi Tochigi 329-2801

TEL: +81-287-35-2048● Nuclear Power Plant Maintenance Research Team
This special research team leverages the combined strengths of CRIEPI’s experts in a diversity of ﬁelds including nuclear power engineering,materials science and electrical engineering, to promote research in the name of securing light water reactor safety, such as countermeasures forthe aging of nuclear power equipment.

68

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report69Keyword Index

Keyword Index
This Annual Report features the key words listed in 1-2. Research
Reports. Explanations for each term are provided on the relevant pages.
Page no.

A

E

L

Seismic Wave Tomography Analysis .. . . . . . . . . .  6

Aggregator ........................ . . . . . . . . . . . . . . . . . . 56

Economic Dispatching Control (EDC) .. . . . . . . . . 36

Laser-Induced Breakdown Spectroscopy (LIBS) .. 40

Smart Community ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Area Requirement (AR) .......... . . . . . . . . . . . . . . . . . 36

Electric double layer electret .. . . . . . . . . . . . . . . . . . . 13

Licensing Analysis Code .. . . . . . . . . . . . . . . . . . . . . . . . . 18

Spark Discharge ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Electromagnetic Immunity . . . . . . . . . . . . . . . . . . . . . . . 42

Lightning Location System (LLS) .. . . . . . . . . . . . . . . . 10

Station Bus .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Environmental Assessment ... . . . . . . . . . . . . . . . . . . . . 52

Linear Regression .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Stem Cell .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Lithium-ion Battery (LiB) .. . . . . . . . . . . . . . . . . . . . . . . . . 58

Stress Corrosion Cracking (SCC) .. . . . . . . . . . . . . . . 20

B
Blind Test .......................... . . . . . . . . . . . . . . . . . 50

F

Load Frequency Control (LFC) . . . . . . . . . . . . . . . . . . 36

Sulfur Hexafluoride (SF6) . . . . . . . . . . . . . . . . . . . . . . . . . 10

Brush-Wipe Method . ............ . . . . . . . . . . . . . . . . . 40

Fuel Ratio .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8Long-term Energy Supply and Demand Outlook . . 54

Surf-riding Phenomenon .. . . . . . . . . . . . . . . . . . . . . . . . . 44

C

G

M

T

Capacity Market .................. . . . . . . . . . . . . . . . . . 12

Gas Turbine Combined Cycle (GTCC) .. . . . . . . .  9Medium Depth Disposal ... . . . . . . . . . . . . . . . . . . . . . . .  7

Tertiary Control Reserve ... . . . . . . . . . . . . . . . . . . . . . . . 36

Carbonized wood fuel ........... . . . . . . . . . . . . . . . . . 30

Gene Expression .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Merit Order (MO) ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Thermal Aging embrittlement.. . . . . . . . . . . . . . . . . . .  7

Chelating Agent . ................ . . . . . . . . . . . . . . . . . .  8

Geological Disposal .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Column ............................. . . . . . . . . . . . . . . . . .  9

Geothermal Saturated Steam ... . . . . . . . . . . . . . . . . . 34

Commercial Frequency (no.) .. . . . . . . . . . . . . . . . . . . 42

30-minute Demand .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

N

3D Structure Model .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Non-technical Skills ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6

Total Industrial Investment in Real Term .. . . . . 54

Concrete Cask ................... . . . . . . . . . . . . . . . . . . 24

H

Connect & Manage . ............ . . . . . . . . . . . . . . . . . . 12

Heat Exchanger .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

P

UContamination classification for salt damage .. . 40

Heat Flux .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

PCB .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Unbalanced Fault .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  9Contract demand ................. . . . . . . . . . . . . . . . . . 48

Hydrodynamic Force .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Performance Demonstration (PD) ... . . . . . . . . . . . . 20

Ultrasonic Phased Array .. . . . . . . . . . . . . . . . . . . . . . . . . 20

Platinum Group Elements .. . . . . . . . . . . . . . . . . . . . . . . 26

Ultrasonic testing .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

CPAT ............................... . . . . . . . . . . . . . . . . . . 10. . 28
Creep Damage ................... . . . . . . . . . . . . . . . .8,

I

Probabilistic Risk Assessment (PRA) .. . . . . . . . . . .  6

Cross Arm . ........................ . . . . . . . . . . . . . . . . . 40

ICRP (International Commission
on Radiological Protection) .. . . . . . . . . . . . . . . . . . . . . 22

Proxy Indicator .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

V

Pulverized Coal Fired Thermal Power Generation .. .  8

VPP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

R

X

Reactivity Initiated Accident (RIA) ... . . . . . . . . . . . . 18

XTAP .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Curtain Wall ....................... . . . . . . . . . . . . . . . . . 52

IEC 61850.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Incident . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

DDistinct Element Method . ...... . . . . . . . . . . . . . . . . . 16
Dose Rate Effect .................. . . . . . . . . . . . . . . . . . 22
Dry Storage ........................ . . . . . . . . . . . . . . . . . 24
Duck Curve ........................ . . . . . . . . . . . . . . . . . 56

Intelligent Electronic Device (IED) .. . . . . . . . . . . . . 46
Intermediate Frequency .. . . . . . . . . . . . . . . . . . . . . . . . . 50

KKumamoto Earthquakes .. . . . . . . . . . . . . . . . . . . . . . . . . 32

Regression Coefficient ... . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Rupturing ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6

YYellow Phase .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Yield Stress .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7

SSecondary Control Reserve .. . . . . . . . . . . . . . . . . . . . . 36

70

Central Research Institute of Electric Power Industry

FY2017 Annual Report

Central Research Institute of Electric Power Industry

FY2017 Annual Report

71

Keyword Index

Keyword Index

Bentonite ......................... . . . . . . . . . . . . . . . . . .  7

Photo by Kira Sugiyama“Industrial research is the cultivation of wisdom,and should therefore contribute to society”
Yasuzaemon Matsunaga （1875-1971）
CRIEPI Founder, 2nd President［ About the Cover Design ］
The lines of diﬀerent colors and angles signify CRIEPI’s tireless eﬀorts tocreate a better futureThese lines, which are the unraveled form of CRIEPI’s ﬁrst letter“C”,
appear in many colors to represent the diverse subject ﬁelds of CRIEPI’s
research and each of these ﬁelds converge at a single point.
That point of convergence is CRIEPI.