FY2016 Annual Repor t

Published in December 2017
Central Research Institute of Electric Power Industry
1-6-1 Otemachi, Chiyoda-ku, Tokyo 100-8126 JAPAN
Tel: +81-3-3201-6601

FY2016 Annual Report

Fax: +81-3-3212-0080

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

CRIEPI

Contents

Overview of the FY2016 Annual Report .................................... . . . . . 2
Ⅰ.

Business Report

Environment
19-Investigation and Analysis of Carbon Pricing Policy Implemented in the U.S. and Europe

１.

Outline of Business Activities ...................................... . . . . .

２.

Research Report2 - 1.

Utility Management

4

20-Detailed Analysis of the Five New Markets in Accordance with Electricity Market Reform... 54

Common Cross-Cutting Field

Outline of Results ........................................................ . . . . . 6

21-Development of an Eﬀective Status Monitoring Technology for Power Generation
Equipment through the Introduction of IoT Technology........................................... . . . . . 14

22-Development of a Technology to Determine OF Cable Abnormalities by Applying
AI Technology

List of Research Subjects

2 - 2.

.... 52. . . ............................... 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................................ 58

Major Research Results
Nuclear Power Generation... . . . . . 16.. . . . . . 18
3-Development of a Human Reliability Analysis (HRA) Guide for the Utilities ............. . . . . . 20
1-Thermal-Hydraulics in Reactor Core Under Fuel Uncovering Condition of Rod Bundle

2-Establishment of a Method to Systematically Evaluate the Activity of Faults in Nuclear

4-Development of a Strength Assessment Technique for Nuclear Reactor Pressure Vessel
Steel Using Ultra-small Test Specimens............................................ . . . . . 22
5-Establish a Radiological Protection System with Scientiﬁc Rationality .................. . . . . . 24
6-Development of a Highly-Reliable Quality Control Technique for an Engineered Barrier
Material........................................................................ . . . . . 26

Ⅱ.

Financial Statement
１.

Overview of Financial Statement ..................... 60

２.

Financial Statement . . . . . . . . . . . . . . . ................................ 62

Thermal Power Generation
7-Proposal of a Life Assessment Method for High Chromium Steel Pipe Considering
Individual Material Properties..................................................... . . . . . 28
8-Development of a Measurement Device for the Rapid ............................... . . . . . 30

Facts & Figures

9-Proposal of a Gas Turbine Power Generation Technology Contributing to Maintaining
Supply/Demand Balance Upon High Penetration of Variable Renewable Energy

Research Results / Intellectual Property .......................... 66

Hydropower Generation

Research Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................... 67........ . . . . . 32

10-Development of Eﬃcient Measurement Method for Water Turbine Vane
Thickness in Hydroelectric Generators........................................... . . . . . 34

Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................................ 68

Renewable Energy
11-Proposal of Evaluation Index of Power System Stability with High Penetration of
Renewable Energy............................................................. . . . . . 36

Electric Power Transmission and Distribution
12-Establishment of a Communications Platform Supporting Smart Grid................. . . . . . 38

13-Development of an Identiﬁcation System able to Predict Lightning Location and Energy
at High Accuracy............................................................... . . . . . 40

14-Development of a Technique to Predict Fusing of Electrical Wires due to High Current
Arc Discharge................................................................. . . . . . 42
. . 4416-Establishing a Power Line-Tree Distance Evaluation Method Utilizing Drones ......... . . . . . 46
17-Proposal of Rational Countermeasures against Snow Damage to Power Transmission Facilities . . 48
15-Development of Technology for the Removal of Transformers Contaminated with Trace PCB

Customers Services
18-Development of a Heat Exchanger with Minimal Frost Accumulation as a part ofAchieving Higher Eﬃciency Heat Pumps........................................... . . . . . 50

Keyword Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................................
. ............................... 70

Overview of the FY2016 Annual Report

Overview of the FY2016 Annual Report
In accordance with the Electricity System Reform, certain movements have become visible, such as
the establishment of a competitive environment in the electric power retail market anddiversiﬁcation/company separation strategies by electricity utilities. Moreover, as part of eﬀorts toachieve the goals of the Reform, the environment surrounding the electric power industry isundergoing signiﬁcant change, exempliﬁed by the establishment of various markets and so forth.
Meanwhile, with electric power demand becoming saturated and related technology entering a stageof maturity, electric power supply is required to be both stable and rational, in addition to being inharmony with the environment.
In response to these changes in the environment surrounding the electric power industry, CRIEPI
conduct research and development initiatives to contribute to solving issues and creating new values.
In FY2016, we produced results relating to the further advancement of safety in nuclear power
generation, stabilization of power distribution systems responding to expanded introduction ofrenewable energy and higher performance of thermal power generation equipment. Furthermore, aspart of eﬀorts to rationalize the maintenance management of electric power facilities, etc., CRIEPI
has also proactively engaged in challenging R&D activities utilizing IoT and AI.
Also, at the same time as reinforcing the functions of our Nuclear Risk Research Center (NRRC) inorder to better utilize risk information, we have established the Energy Innovation Center (ENIC),
which aims to create new customer value leveraging leading digital technologies and formed a
research promotion framework. Parallel to these eﬀorts, with the aim of forging a sustainable businessfoundation, we are steadily proceeding with“structural reform”by promoting establishment ofresearch bases, streamlining our organizational structure, rationalizing tasks, etc.
As an in-house research institution comprising of researchers possessing a wealth of expertisecovering the electric power supply chain and unique research equipment, CRIEPI will continue
creating and oﬀering research results of value in an eﬀort to transform technologies and systems
relating to the supply and utilization of electric power and other energy, thus contribute to theelectric power industry and society at large.
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

FY2016 Annual Report

Central Research Institute of Electric Power Industry

FY2016 Annual Report3

Ⅰ. Business Report1.

Outline of Business Activities

1. Outline of Business Activities
As the central research institution of the electric power industry, CRIEPI produced various research
results useful for solving common issues faced by the electric power industry, engaged in researchwith foresight by predicting issues likely to occur in the future and, ultimately, contributed to society.

■ Strengthening and developing fundamental research ability witha mid-to-long term perspective

・With consideration to the issues predicted to occur in the

future concerning the electric power industry, CRIEPI has
clariﬁed the fundamental technologies necessary to solve
such issues and enhanced new technological ﬁelds while atthe same time scaling down technologies we judged to be of■ Promoting research to lead change and producing/providing
results

・CRIEPI injected resources with priority to R&D useful for solving common issues faced by the electric power industry andproduced/provided results steadily. Also, we used our foresight to predict issues that may surface in the future insofar as
technologies and systems relating to electric power, energy supply and energy usage are concerned, then engaged in research toprovide solutions to such issues and new value. Examples of our achievements include establishment of a systematic evaluation
method for fault activity for application in the nuclear power generation ﬁeld, a proposal for gas turbine power generation
technology to help maintain supply/demand balance during times of large-volume naturally-ﬂuctuating power in the thermal
power generation ﬁeld, establishment of a communications platform to support smart grids in the power distribution ﬁeld, a
detailed analysis for ﬁve new markets due to the Electricity System Reform in the utility management ﬁeld and ﬁnally,
development of eﬃcient status monitoring technology for power generation equipment through IoT technology incommon/cross-ﬁelds.

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

・CRIEPI responded to accidents and issues at electric power industry worksites, as well as ﬂexibly and swiftly provided suitable
solutions for such situations.

See Fig. 2

・In regards to consigned research at the request of the Japanese government, etc. CRIEPI undertook research such as thedevelopment of common infrastructure technology concerning the building of next-generation power distribution systems, etc. tocontribute to solving issues faced by the electric power industry, as well as advanced research to enhance and reﬁne our researchcapabilities.

low priority to better utilize researchers where necessary. Asof the end of FY 2016, we have a total staﬀ of 725, consistingof 642 researchers and 83 administrative staﬀ members.
These researchers are specialized in a wide range of diverse

Administration
83
Research support&
management
85
Socioeconomics
38
Information &communications
34

See Fig. 3

Fig. 3

research facilities critical to solving issues in the electricCommon/cross-ﬁelds 6

Utility management 1.0 %Environment 7

Environment
Consumer services 10.1%

Nuclearpower
generation

Consumer services 5※Renewable energy

was promoted in the
7 research themes ofother related ﬁelds

Common/cross-ﬁelds 2.5 %4.5%Thermal power
generation

30

Power
distribution

30

Renewable energy 1※

Power
distribution

Thermalpower
generation

43.7%

20

Hydropower
generation 1

Fig. 1 No. of research themes by ﬁeld for FY2016

Nuclear power
generation 14.6 %Fig. 2

18.6%

Hydropower
generation
5.0%

Consigned research projects from electric
power utilities for FY2016(percentage of cases by ﬁeld)■ Formulation of business strategy and establishment of promotional
systems to provide appropriate response to needs

・In line with the advancement of the Electricity System Reform, CRIEPI formulated mid-to-long term business strategies
in order to respond to changing R&D needs in each business ﬁeld, such as power generation/distribution and retail.
Moreover, we ensured multilayered communication with electricity providers, and collaborated with them to establish
and update an R&D roadmap. In the process, we clariﬁed CRIEPI’s roles and research projects for promotion.
・Towards the realization of our business strategies, CRIEPI established a Risk Informed Decision Making Promotion
Team within our Nuclear Risk Research Center (NRRC) in order to more eﬃciently achieve the introduction of safe
nuclear power plant operation and further safety enhancement from a risk management perspective. We alsoestablished other promotional systems, such as the Energy Innovation Center (ENIC). This Center aims for thesophistication of electric power supply/demand management for the coordination of the consumer side and electricity
provider side, as well as support of digital transformation of the electricity business.

Chemistry
41

Personnel conﬁguration by subject ﬁeld as ofend of FY2016

power industry based on research strategies for each ﬁeld. These included the Micro Focus X-ray CT and Transmission
Electron Microscope which make it possible to evaluate activity within a nuclear power plant’s grounds and nearby
faults with greater accuracy, and Measurement Equipment for Leakages During Distribution Pipe Breakages, which
simulates breakages in the grid pipes of power generation equipment and quantitatively evaluates the impact of leakedgas, thus leading to more eﬃcient facility maintenance systems.

See p.13 [Major New Research Facilities]

・We promoted the development of personnel with highly-specialized knowledge and in-depth knowledge on the electric
power industry through dispatching our researchers on a long-term basis to research institutions and electric power
utilities, etc. both in Japan and abroad.
・We strengthened and expanded our research networks through actively promoting joint research and human interaction
with institutions both in Japan and abroad possessing sophisticated technology in energy-related R&D (EDF in France,
EPRI in the U.S., etc.) in an eﬀort to enhance our research abilities.

Utility management 3

Mechanical
88

Nuclear engineering 51 Biology
36

construction to socioeconomics and more (Fig. 3), where 396
researchers completed their doctorates.

Civil engineering&
construction
115

Environment 52

research ﬁelds, from electricity through civil engineering and・CRIEPI carefully selected, introduced and renewed large

Electricity
102

See p.67 [Research Networks]■ Contributed to a society that utilizes our intellectual property
and proprietary technologies

・CRIEPI broadly disclosed its research results to the general public through research reports and academic papers so thatsuch results could give back to the electric power industry and society at large. Moreover, CRIEPI’s proprietary patents
and software were broadly oﬀered to and utilized by electricity providers, manufacturers and universities, such as thelicensing of CALDG (a power distribution grid comprehensive analysis tool).
See p.66 [Research Results / Intellectual Property]
・Through participation in various committees run by government bodies and academia, CRIEPI contributed to the establishmentof various policy, standards and technical guidelines relating to energy, such as the Implementation Standard for Probabilistic
Risk Assessment of Nuclear Power Plants (level 3 PRA version)・In addition to fulﬁlling 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, CRIEPI performed
short-circuit tests on power equipment such as circuit breakers, etc. upon request from electric power utilities, manufacturers,
etc. at our High Power Testing Laboratory.

■ Steady promotion of research base development, task
rationalization and cost reduction

・CRIEPI continued to steadily promote development of research bases in order to strengthen research ability and reduce
ﬁxed management overheads through initiatives such as completing a new building within Yokosuka Area andrelocating research functions from Komae Area.
・In order to build a sustainable business foundation, CRIEPI streamlined its organizational structure and reduced ﬁxed
management overheads at the same time as engaging in ongoing initiatives to reduce costs for both research andoperations aspects, such as promoting competitive quotations in procurement, and rationalizing operational tasks
through outsourcing.

■ Overview of ﬁnancial statement

Current revenue for ﬁscal 2016 was a total of 30,950 million yen, which comprised of 25,240 million yen in ordinary
beneﬁts and 5,410 million yen in business proﬁt from consigned research projects undertaken at request by the Japanese
government, electric power utilities, manufacturers and so on. Current expenditure was a total of 29,800 million yen,which included 9,730 million yen in personnel expenditures and 20,060 million yen in overheads. The ordinary net
increase for FY2016 was 1,150 million yen.

4

Central Research Institute of Electric Power Industry

FY2016 Annual Report

See p.60 to p.63 [II. Financial Statement]

Central Research Institute of Electric Power Industry

FY2016 Annual Report52. Research Report
2–1.

2–1.

Outline of Results

Outline of Results
With an awareness of a timeline to lead change in the electric power industry, CRIEPI
broadly engaged in initiatives on topics in urgent necessity as well as those predicted
to arise in the future, and produced/provided research results on a timely basis.
In addition to the eight areas, comprising of nuclear power generation, etc., corresponding with the electric power

Establishment of probabilistic risk assessment (PRA) technology
Good PRA
Plant speciﬁc PRA whichis comparable to theinternational state-of-thepractice and improved
with the Japanese
operating experience.

・In preparation for conducting the Japanese ﬁrst Good PRA at the Ikata Nuclear Power Plant, CRIEPI gathered thelatest information about the advancement of PRA from international experts.
・To improve the human reliability analysis (HRA) technique in Japan, CRIEPI established a qualitative method
considering the failure of human cognitive processes and combined this with the conventional quantitative method
to create an HRA guide for use in Japan.

See p.20

・In order to establish protective measures against HEAF ﬁres (secondary ﬁres caused by high energy arcing faults),
CRIEPI conducted internal arc tests using high voltage metal-enclosed switchgear components and clariﬁed ﬁreindustry supply chain, we newly established a“common/cross-area”category that looks at issues common acrosspropagation conditions.

the individual areas and promoted research by closely liaising with each area. Please refer to p.14 for a list of theseresearch subjects. Below is an outline of the research results best representing each area. Also, from p.16 onwards,
we have provided detailed descriptions of the major research results worthy of special mention.

Evaluation of impact of major accidents● Keywords used in the index (p.70) are shown in bold. Explanations have been provided for some keywords in the・WinMACCS code, developed by the U.S. Nuclear Regulatory Commission (NRC) to probabilistic risk assessment

Major Research Results (p.16 ‒ 59).

for environmental accident release (level 3 PRA), have been applied, and we clariﬁed that the atmosphericdispersion coeﬃcient of radioactive substances had a relatively large inﬂuence to the dose estimation.
・We developed a simple calculation tool to evaluate the atmospheric dispersion of radioactive substances during
normal and accidental released cases with consideration of wet and dry deposition, building eﬀects, etc.

Promotion and advancement of independent public safety activities

Nuclear Power Generation

Non-technical Skills
In contrast to individual
technical skills such as
specialist knowledge andskills, non-technical skills
refers to skills such ascommunication andteamwork mainly engaged
in within an organization.

Greater advancements in safety of light water reactors
Greater advancements in evaluation techniques for core damage
・In order to improve the reliability of preventative measures against core damage in beyond design-basis accidents
of nuclear reactors, CRIEPI conducted experiments which simulated a rapid boiling state (high temperature/highspray in the containment vessel under the accident was conﬁrmed by the temperature evaluation by the numericalthermal-hydraulic analysis code.
actual scale ﬁlter vent apparatus, and a ﬁlter vent performance evaluation tool was developed.

130°0’0”E

Strainer

containment vessels does not peel away during loss-of-coolant

Plug

Oriﬁceaccidents, CRIEPI conducted mock tests for the 39 types ofInletpaint speciﬁcations in accordance with the related guideline(JEAG 4628-2010) and assessed their soundness. As a result,
we conﬁrmed that 13 types complied with this guideline.

toughness evaluation technique using a miniature test
welded metal material in the same way as the base metal
Iwate

Prefectural Oﬃces

Fukui（kg/m2）

Tottori

April 2016, etc. and clariﬁed it was possible to appropriately
assess fault activity.

See p.18

Tokyo・In preparation to introduce a probabilistic risk assessment
gathered and analyzed the latest case studies from both Japanand abroad and, positioning the Ikata Power Plant as the pilot
plant, formulated a plan for the implementation of aprobabilistic earthquake hazard assessment.
・In order to contribute to the assessment of impact on nuclear
power facilities due to volcanic eruption, CRIEPI compiled

Osaka

30°0’0”N

technique for the evaluation of earthquake hazards, CRIEPI

specimen developed by CRIEPI could also be applied to

SapporoKagoshima

Okinawa0
0 ｰ 0.1
0.1 ｰ 1
1 ｰ 1010 ｰ 100
100 ｰ 200
200 ｰ 500
500 ｰ 1,000
1,000 ｰ 1,500
1,500 ｰ 3,000
3,000 ｰ 6,000
6,000 ｰ 10,000
10,000 ｰ 15,000
15,000 ｰ 20,000
20,000 ｰ

0 125 250

130°0’0”E

40°0’0”N

ﬁeld surveys in areas aﬀected by the Kumamoto Earthquake of6

When coolant (water) inside
a nuclear reactor leaks out
due to pipe damage, etc.
causing a reactor core tolose its cooling function.

Reducer

・As it is important that the paint inside nuclear reactor

reactor pressure vessels (RPVs) we clariﬁed that the fracture

140°0’0”E・C R I E P I e s t a b l i s h e d a f a u l t a c t i v i t y a n a l y s i s ﬂ o w t oaround nuclear power plant sites. Using this ﬂow, we conducted

PRA is a quantitative
method of evaluating thevulnerability of nuclear
facilities by systematicallyand exhaustively
analyzing various
potential accident
scenarios in the facilities
and prioritizing the
scenarios in order of theirrisk evaluated with the
combination of theirfrequencies andconsequences.

thinning rate and remaining life of power plant pipes (right).
Loss-of-Coolant
Accidents

technique for embrittlement caused by neutron irradiation in

Establishment of evaluation techniques forlow‐frequency phenomena
systematically assess the activity of faults which exist in and

Probabilistic Risk
Assessment (PRA)

Valve
Diﬀuser

Advances to safety technology for light water reactors

・As preparation for the establishment of an assessment

material.

OutletExample of thickness reduction prediction
using FALSET

See p.22

Maintenance and expansion of radiation protection systems
・CRIEPI proposed a surface contamination dosage evaluation model employing rational exposure scenarios for
30°0’0”N

An exhaust unit connect
to a nuclear reactor
containment vessel tosuppress abnormalpressure rise within thevessel. This unit isequipped with a ﬁlter tosuppress the release ofradioactive substances inthe environment.

・Test data on the removal characteristics of major radioactive materials in various ﬁlters were acquired using an

40°0’0”N

Filter Vent

Safe operation of light water reactors

wall thinning (FALSET) which makes it possible to predict the

See p.16

・In addition to expanding the database on the transition behavior of radioactive materials, the eﬀectiveness of theassess training content and applied the same training technique at the Shimane Power Plant.

・CRIEPI developed and improved prediction software for pipepressure) due to falling of BWR control rods and clariﬁed the behavior of steam generation of a fuel conglomerate
which accompanies the rapid rise in temperature of a fuel cladding surface.

・Regarding non-technical skill training for emergency response team personnel, CRIEPI standardized the method to500
km

140°0’0”E

Distribution of amount of the accumulated
ash fall in Japan over the past 330,000 years

information on volcanic ash fall from the past 330,000 years and created a chart showing the distribution of

formulating guidelines for moving out of commodities with radioactive contamination in emergency, existing(post-accident) and planned (normal times) exposure situations, and reﬂected this to the relevant guideline(Committee for Radiation Protection Committee of the Japan Health Physics Society). We also proposed a new
indicator for radiation risk evaluation and clariﬁed that, in regards to the eﬀect of radiation on circulatory diseases,
the current standards relevant to cancer provided suﬃcient protection.

See p.24

Support for radioactive waste disposal operations

amount of the accumulated ash fall in Japan (top right).
・In order to assess the structural soundness of major equipment in nuclear power plants against earthquakes,
CRIEPI conducted a vibration test on the motor-operated valve actuators used in nuclear power plants andconﬁrmed the motor-operated valves moving function under vibration conditions up to a maximum acceleration of
20G through appropriate anti-earthquake reinforcement.

Central Research Institute of Electric Power Industry

FY2016 Annual Report・In order to establish a technique to easily control the quality of bentonite, an artiﬁcial barrier material, we veriﬁedthat the ﬁlter paper method known to be eﬀective could achieve a measurement accuracy on par with thecolorimeteric method, which utilizes an apparatus, if the instruments and steps used in measurement wereregulated and standardized. Standards are expected to be established for this technique.

Central Research Institute of Electric Power Industry

See p.26

FY2016 Annual Report

7

2–1.

2–1.

Outline of Results

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

Thermal Power Generation

・As a countermeasure for unstable power output by high penetration of variable renewable energy, CRIEPI reviewed
target performance values to be developed for gas turbine combined cycle (GTCC), which has superior start-up
performance and load following performance. The target performance values examined included shortening start-up

Ensuring reliability of existing thermal power plants

time and improving load following speed. At the same time, we assumed the future supply/demand situation
predicted to have high penetration of variable renewable energy and tentatively calculated the eﬀect that GTCC
with the target performance values had on supply/demand management.

・In order to reduce the number of unscheduled stoppages at thermal power plants due to corrosion damage, etc.

See p.32

CRIEPI developed a rapid proﬁle measurement technique and thinning analysis technique for the water wall tubes
of boilers. These techniques utilize a portable 3D proﬁle measuring device and aim to establish boiler tubes
diagnosis technology that can be utilized in the ﬁeld.
・Through analysis of a database for creep experiments on high-Cr steel
scrap, CRIEPI clariﬁed that the variation in welded joint life depended

Temp, Kon the life of the base material as well as clariﬁed that a correlation

1300

existed between base material life and ﬁne precipitates throughHydropower Generation

900

analysis using an aberration-corrected transmission electron
microscope (Cs-TEM). By combining these observations withmicroscopic sample technology, we proposed a life evaluation methodable to consider the speciﬁc properties of pipes in each power plant.
Gas Turbine
A rotational-type motorthat converts the energyof high-temperature/highpressure gas into mechanicalpower.

Disaster prevention and maintenance and management
for hydropower facilities(a) Computational simulation

See p.28
・To reduce the maintenance cost of gas turbines, CRIEPI developed an
estimation method of turbine blade temperature which controls life of

・As a part of risk assessment to prevent public damagea gas turbine blade. The developed method uses a polynomial toresulted by overﬂowing or ﬂooding from hydropower

describe a correlation between the blade temperature and parameters

calculate the water arrival time, water depth and ﬂow speed

temperature at various operating conditions. Estimated distribution ofthrough minimal data entry, such as the target area, etc.

temperature on a 1000℃ class gas turbine blade with the developed(right).

method agrees well with a computational simulation (right ﬁgure).
・To expand the eﬀective utilization of coal ash, we developed a・In order to eﬃciently measure the thickness of water turbine(b) The developed method

neutron boron gauge which focuses on the properties of boron thatvanes used in hydropower even in the narrow space between
individual vanes, CRIEPI developed a method to photographcause it to speciﬁcally capture neutrons in order to rapidly measure Comparison of estimated temperature
distributions of a gas turbine blade
the boron content in coal ash.
See p.30

the front and back faces of the water turbine vane using asmall line laser and small camera, then accurately
reproducing a cross-section proﬁle of the water turbine vaneconsidering the eﬀect of stress multiaxiality on the creep
damage evaluation.
・As part of eﬀorts to expand the use of bio-reformed ash as theingredient for woody biomass, CRIEPI clariﬁed that by
improving the energy density of bio-reformed ash throughPulverized Coal-ﬁred
Thermal Power
Generation
A method of generating
power by pulverizing coal
into a powder form,
combusting this in aboiler and driving turbines
using the generated
steam.

consolidation, an equivalent result to that of bituminous coal,
which is commonly used for pulverization, could be obtained(right).

50Geothermal Reservoir
Forest oﬀ-cuts
Bio-reformed ash
Consolidation productpredicted with the same accuracy as a round bar specimen by

Scrap
Bio-reformed ash
Consolidation productA renewable resource
derived from wood lessexpensive than petroleum
and with lower carbon
dioxide emissions.

10High chlorine content
Coniferous
Bio-reformed ash
Consolidation product

Wood Biomass

Comparison of pulverization properties ofcoal and biomass ash

Diversiﬁcation of fossil fuels
・With the aim of reducing fuel cost due to fuel type expansion in thermal power generation, as part of eﬀorts to

Fuel Ratio
A factor indicating the
combustibility of a coal
which focuses on theweight ratio of ﬁxed carbon
with poor combustibility tovolatile matter with good
combustibility.

8

utilize, high-fuel ratio bituminous coal (fuel ratio 2.5 ‒ 4) which does not burn easily and is not utilized in JapaneseA“reservoir”refers to arock layer or stratum
where water that has
seeped through theground surface has
accumulated and if thewater in the reservoir isheated due to being in ageothermal region, etc.,
this is then referred to asa“geothermal reservoir”.

Fracture Belt
An area where a force isbeing applied in a fault
adjacent to a strike-slip
fault in the same direction.

pulverized coal-ﬁred thermal power plants, CRIEPI evaluated the grinding characteristic when bituminous coal andhigh-fuel ratio bituminous coal were blended and clariﬁed the eﬀect of coal blending ratio on grinding power andpulverized coal particle diameter.
・In order to achieve optimal operation of pulverized coal-ﬁred thermal power plants, the coal operation evaluation
system has been developed the function enabling calculation of boiler eﬃciency considering coal properties andoperation conditions was incorporated into this system and cost calculation accuracy was improved.

Central Research Institute of Electric Power Industry

FY2016 Annual Report

See p.34

15

AD ash(Sub-bituminous coal)conﬁrmed that creep lives of notched specimen werebased on image data.

Simulation of virtual ﬂooding assuming overﬂow(The background ﬁgure uses OpenStreet Map
data)

20

LD ash(Bituminous coal)used in actual high temperature components, CRIEPI

Grinding power base unit, kWhe/ton

Thermal technology to mitigate environmental load
creep-fatigue conditions for material which has not yet beenHighfacilities, CRIEPI developed an analysis program to easilyin operation, enabling rapid and easy estimation of the blade

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

Water
Low
level

Alteration Belt
An area where the rockbed has been altered dueto heated water fromdeep underground in ageothermal region, etc.

Renewable Energy
System stabilization on large‐scale introduction ofrenewable energy
・From the perspective of power grid stability (particularly during accidents), it is necessary to operate a synchronous
generator of a certain scale even during high penetration of renewable energy. CRIEPI proposed the“generator
stop ratio”as a useful indicator to evaluate an appropriate ratio of the synchronous generator.

See p.36

Expanded introduction of biomass and geothermal power
generation
・In order to contribute to the advancement of geothermal reservoir exploration technology to increase the eﬃciency
and lower the costs of geothermal development, CRIEPI conducted a survey relating to the development ofexisting geothermal power plants and clariﬁed the importance of fracture belts and alteration belts as well as
appropriated items to suit depending on the strata type thereof.

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Outline of Results

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

Electric Power Transmission and Distribution

System stabilization on large‐scale introduction of renewableenergyResponse to reforms in electric power system

・As part of eﬀorts to accurately assess the output variation inphotovoltaic power generation, CRIEPI developed a solar radiation
estimation/prediction system with high accuracy by utilizing satellite
imagery from Himawari 8, which has signiﬁcantly improved
performance compared to Himawari 7, such as shortened monitoringtime interval (right).

・Services utilizing smart meters and IT are expected to become more established due to the introduction of smart
grids. However, the interoperability between the applications for the services is a problem due to the diﬀerence
among the communication standards for each application. In order to solve this issue, CRIEPI developed acommunication platform that enables the applications to use each standard via a common API (Application
Program Interface).
See p.38

Example of a screen display for the solar
radiation estimation/prediction system

Formation, maintenance and upgrades of substations andtransmission lines
Advancing preservation technology for aged facilities

A phenomenon whereby
an extremely small
amount of water diﬀuses
into the insulation layer of
XLPE (cross-linked
polyethylene) cables,
condensates at localized
points where the electricﬁ e l d is h ig h a nd fo rms
branches (tree).
“Bridging”is when thewater tree grows to thelength equal to thethickness of the insulation
layer between inner andouter conductors of XLPE
cables.

Laser-Induced
Breakdown
Spectroscopy (LIBS)
A technology whereby laser
pulses are focused on thematerial being measured
causing a plasma to form,
then the light emitted fromthe plasma is analyzed,
making it possible toperform identiﬁcation andconcentration measurementof elements contained
within the material being
measured.

SiC Power
Semiconductor
A semiconductor element
for power equipment
made from silicon (Si) andcarbon (C), with excellent
voltage resistance andhigh-frequency operation.

10

Speciﬁed point

Water Tree/Bridging

・Aiming at establishing a preventive maintenance for
Aerial Image 3D model
Projection ofoperation of transmission towers, CRIEPI developed a
3D model on
method for corrosion evaluation of each overhead
to the aerialtransmission tower. Moreover, in order to eﬃciently assessimage
the state of corrosion, CRIEPI developed a technique toextract the transmission tower’s steel portion from an aerial
image (right).
There is atransmission
・In order to detect water-tree degradation in an insulation
tower underlayer of XLPE cables for power distribution, CRIEPI found a
the red line
potential solution involving applying current integration
method to the XLPE cables for the ﬁrst time and detecting
short water trees before they bridge the cable insulation,
which was previously diﬃcult to achieve.
Example of results of transmission
・In order to eﬃciently measure density of deposited salt,
tower extraction from an aerial image
which leads to the deterioration in insulation performanceof porcelain insulators, CRIEPI established a method
utilizing laser-induced breakdown spectroscopy (LIBS) which shows potential as a means of performing remotemeasurement rapidly on-site without the need to remove insulators from power transmission equipment.

Support to streamline facility design and operate facilities
・As part of eﬀorts to save labor spent on surveillance rounds and inspection of transmission/transformer equipment
in line with lightning strikes, CRIEPI has developed the advanced lightning location system, which able to pinpoint
lightning strikes at high accuracy (with an error margin of 50 m) as well as estimate the lightning energy necessary
for damage level evaluation.
See p.40
・In order to prevent electric wire (power line wire, ground wire) melting/breaking caused by high current arc
discharge such as lightning, as part of eﬀorts to select electric wires which do not melt/break easily, CRIEPI
developed a technique to calculate the extent of melting/breaking in strands which comprise an electric wire, thenpredict the number of strands that have been melted/broken from the calculated melting amount.
See p.42
・CRIEPI made progress in the development of cable cleaning technology used in the removal of trace PCB found intransformers in use and newly proposed an area-speciﬁc cleaning making it possible to clean each individual
portion of a transformer.
See p.44
・In order to control the distance between power cables and surrounding trees, CRIEPI developed a method to easily
and inexpensively measure distance using a drone and showed it was possible to measure distance with the sameaccuracy as the conventional aerial measurement.
See p.46

Next‐generation equipment technology anticipating future facility upgrades
・As a part of eﬀorts for the practical application of high-voltage SiC power semiconductor devices, CRIEPI
developed a technology to eﬀectively modify the electric properties of SiC by adding vanadium element during the
crystal preparation process. This is expected to help prevent conduction degradation and improve switching
performances.

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Forming, maintaining and update power distribution
facilities
Smart Meter
An electric power meterequipped with acommunication function.
Smart meters utilize the
network between electric
power companies andconsumers to provide
services such as visualizationof electricity usage.

・CRIEPI clariﬁed the circumstances when a smart meter is damaged
due to energy from lightning current passing through arrester
equipment inside smart meters when power distribution lines are
struck by lightning. We also clariﬁed that the further away a smart
meter was from a pole transformer, the greater the energy fromlightning current passing through the arrester became, meaning thesmart meter was more likely to be damaged (right).

Breakage of surge arrestor

Melting/breaking of wiring board

Failure of a smart meter due toenergy from a lightning current

Response to disaster and human risks
Cable Surﬁng
Phenomenon
A phenomenon whereby
underground power cables
move due to the vibrationfrom vehicles passing
overhead. In the worst casescenario, the movement of
the cable core could trigger
insulation damage.

・CRIEPI proposed a model to express the surﬁng phenomenon observed in underground power transmission cables
and veriﬁed the adequacy of this model through comparison with the result of a mock cable movement test
conducted on a small-scale indoor mock-up one-tenth of actual size.
・In regards to the three types of snow damage to power transmission equipment (heavy snow accretion, galloping,salt/snow damage), CRIEPI established a method to predict regions with high potential of snow damage based on
the latest ﬁndings and proposed a ﬂow to select appropriate snow damage countermeasure products to suitregion-speciﬁc weather patterns and equipment speciﬁcation.
See p.48

Customers Services
Bi-directional
Non-contact Power
SupplyNon-contact power supply
is one form of electric
power supply and is also
referred to as“wirelesspower transmission”. Its
use is anticipated in electricvehicles (EV). If power canbe supplied not only fromthe power grid to an EV
but also vice-versa, themethod is referred to as“bi-directional non-contact
power supply”.

Promotion of energy conservation and electriﬁcation andenhanced customer satisfaction
・As part of eﬀorts to increase heat pump eﬃciency, in order to prevent the accumulation of mist on the unit outsideof the heat pump chamber (heat exchanger), CRIEPI developed a non-mist heat pump which utilizes a heatexchanger coated in adsorbent. By doing this it is anticipated that eﬃciency will improve by 10 to 30% ofconventional heat pump hot-water supply systems.
See p.50
・In order to optimize the design of ventilation fans for electric kitchens for further promotion of saving energy
activity, CRIEPI conducted a test to evaluate the required amount of ventilation. The electric kitchen ventilation
design guideline draft prepared based on the result of this test has been reﬂected in JEHC103 - 2017 (Japan
Electro-Heat Center).
・As a part of eﬀorts for the practical application of bi-directional non-contact power supply using a magnetic
resonance method as a means to supply power to electric vehicles, we revised the material used in power supply
coils and improved transmission eﬃciency.

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Outline of Results

Outline of Results
Common technology for application in diverse ﬁelds

Environment

・As part of eﬀorts to establish a rational maintenance & operation technology for electric power equipment, CRIEPI
engaged in activities for the advancement of energy harvesters (for energy harvesting), which is necessary for
maintenance-free monitoring of them. We succeeded in prototyping a vibrating power generation device capable

Response to environmental policy and regulationsof power generation even at frequencies of 100 Hz or less, which had been diﬃcult to use up until now.
See p.56

・CRIEPI analyzed precedents on introduction of carbon pricing by Europe and the US, regions leading the way inthis area, and extracted issues in preparation for future policy study. Moreover, in regards to implicit carbon price,
we organized a deﬁnition, evaluation methods, etc.

See p.52

・Toward the next IPCC (Intergovernmental Panel on Climate Change) report, CRIEPI developed a method tocompare the uncertainties relating to climate, policy and technology in long-term CO 2 emissions reduction

・In order to alleviate the workload and improve eﬃciency regarding maintenance of electric power equipment,
CRIEPI engaged in the development of an AI technique which is both simple and capable of high-level patternawareness. By applying this technique to the analysis method for insulation oil widely used in judgement of OF
cable condition, we succeeded in improving the correct judgment rate from around 50% to around 80%
See p.58

scenarios and quantitatively showed that the uncertainty of climate prediction is large compared to that of policy
and technology.
・In order to assess changes in the source apportionment of ﬁne particulate matter (PM2.5), CRIEPI conducted a
numerical analysis utilizing a chemical transport model. The result clariﬁed that the contribution of domestic
anthropogeninc sources between the years 2000 and 2010 was practically steady (around 40%) and, of this, theimpact of power plants was around 2.8 to 3.9%.
Environment
Assessment
A process of assessing the
likely environmental impacts
of a proposed project ordevelopment in advance bybusiness operators to
prepare a better projectplan from the perspective ofenvironmental conservation.

Micro Focus X-ray CT and Transmission Electron MicroscopeEﬃcient environmental assessment

Major new research facilities are a micro focus x-ray CT with an extremely small beam diameter which enables to obtain 3D structure at ahigh spatial resolution in the range of around 10 μm and a general-purpose transmission electron microscope. By using these facilities it is・As a substitute to the wind tunnel experiment, CRIEPI developed a

C/C0
１

3D numerical model to predict exhaust gas dispersion of low-stack
LNG thermal power plant and wind speed distribution aroundcoal-storage yard (right). Moreover, we improved the 3D warm

possible to evaluate the activity of the faults within and around power plants based on microscopic structural analysis.

10 -2

eﬄuent dispersion prediction model developed by CRIEPI, making it
possible to predict the recirculation ratio of warm eﬄuent when

10 -4

taking cooling water (sea water) from the sea near the power plant.

Utility Management

Major New Research Facilities

10 -5

3D numerical model for the prediction of
exhaust gas dispersion as a substitute forthe wind tunnel experiment

Ensuring consistency of power system reforms and energy measures
・We clariﬁed that the share of new suppliers in various areas of Japan after retail market fully opening up could bearound the same as European countries, taking account of potential price reduction rate due to switching.
・We investigated the liquidity of European wholesale markets and clariﬁed that trading volume of spot market was
Gross Bidding
A system whereby thegeneration division andretail division within anincumbent power utility
trade power through power
exchange in order to boost
liquidity of wholesale power
market.

expected to increase through the adoption of gross bidding, which is already set to be introduced in Japan, andimplicit auctions for capacity of interconnection. We also demonstrated that the volume could be inﬂuenced by thewholesale electricity price.
・After investigating overseas precedents relating to new markets design created based on electric system reform,and conducting a quantitative analysis of the model Japanese wholesale market, we clearly indicated that, for

Measurement Equipment for Leakages during Distribution Pipe Breakages
This equipment is capable of high-accuracy monitoring and measurement of the outﬂow behavior of gas from breakages in the grid
distribution pipes of power stations by simulating such a situation then utilizing a high-speed camera and laser. Findings obtained from thisequipment, when combined with the results obtained from pipe defect analysis and cognitive analysis, will help to choose a suitable
maintenance method for grid distribution pipes used in power stations.

coexistence of high penetration of renewable energy and security of supply, it is advisable to create a capacity
market, etc.

See p.54

Common Cross-Cutting Field
Electric Power Supply/
Demand Management
TechniqueA technique to manage thesupply and demand ofelectric power and maintainelectric power quality
through the coordination ofenergy equipment
possessed by consumers
and the electric power grid.

12

Overall optimization through supply/demand coordination
・With the aim of establishing an electric power supply/demand management technique, CRIEPI has added afunction to calculate electrical device power consumption depending on regional weather conditions and PV
power into the electric power supply/demand simulation tools developed to date, making it possible to arbitrarily
simulate electric power supply/demand for any given area in Japan.

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Central Research Institute of Electric Power Industry

FY2016 Annual Report13List of Research Subjects

List of Research Subjects

Nuclear power generation●Greater advancements in safety of lightwater reactors■ Greater advancements in evaluation techniques forcore damage

・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 in Severe Accident■ Establishment of evaluation techniques forlow‐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‐resistant evaluation techniques onground and structures of nuclear power plants■ Establishment of probabilistic risk assessment (PRA) technology

・Development of risk assessment methodology for nuclear facilities

・Promotion of Risk Informed Decision Making Process at Nuclear Power Plants■ Evaluation of impact of major accidents

・Development of evaluation method of radioactive material in environment■ Promotion and advancement of independent public
safety activities

・Development of voluntary safety action programs for nuclear power
stations in consideration of human factors●Safe operation of light water reactors■ Advances to safety technology for light water reactors

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 in thermal power plant
・Improvement of remaining life assessment, diagnosis and maintenance for 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 at coolingwater 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
・I n v e s t i g a t i o n a n d E v a l u a t i o n o f t h e i n ﬂ u e n c e o n t r e n d o f t h eenvironmental 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 expanding use of biomass in thermal power generation●Diversiﬁcation of fossil fuels
・Diversiﬁcation Technologies of Fuel Types for Thermal Power Generation●Response to large‐scale introduction of renewable energy
・Development of technology to improve load following capability ofthermal power systems●Response to risk of disasters
・Natural disaster assessment and measures for thermal power plants

・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 radiation intensity reduction
・Improvement of integrity evaluation method for reactor pressure vessels
・Improvement of integrity evaluation method for core internals, piping and othercomponents
・Development of nondestructive inspection technologies for components andpiping in nuclear power plants■ Maintenance and expansion of radiation protection
systems

Hydropower generation●Disaster prevention and maintenance and management
for hydropower facilities
・Development of disaster prevention and maintenance technologies forhydropower facilities

・Quantitative evaluation of low‐dose radiation risk and reﬂection toradiation protection systems■ Greater advancements in light water reactor technology
・Technology improvement for performance evaluation of nuclear fuel and reactor core

●Establishment of nuclear fuel cycle technology

・Development of long‐term storage management technologies for spent fuel・Development of technology to improve safety and stable operations of nuclear fuelreprocessing plants
・Safety assessment for overseas return waste storage
・Securement of options for future nuclear fuel cycle●Support for radioactive waste disposal operations
・Development and systematization of long‐term safety assessment technologies
for radioactive waste disposal
・Development of streamlined approach for the implementation of radioactive
waste disposal project●Ongoing long‐term use of nuclear reactors
・Technology development for metal fuel fast reactors and pyroprocess●Decommissioning nuclear reactor facilities
・Development of decommissioning and defueling technologies

14

Central Research Institute of Electric Power Industry

FY2016 Annual ReportElectric power transmission and distribution●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 technology to build power information communications
infrastructure utilizing general‐purpose communications technology●Formation, maintenance and upgrades of substations
and transmission lines

Customers 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
・Value evaluation for next‐generation power demand management■ 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 operatefacilities
・A study on rationalization of insulation design of the power apparatus andsystems 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 tosecure 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 in electrictransmission facilities
・Development of maintenance and replacement technologies of communication
systems used for power system monitoring, protection and control■ Next‐generation equipment technology anticipating futurefacility upgrades

Environment●Response to environmental policy andregulations
・Research on domestic and international climate change policies
・Scientiﬁcally and economically rational scenarios to reduce CO2 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

・Evaluation techniques for power semiconductors
・Development of high eﬃcient electric power distribution facilities fornext generation●Response to changes in supply form anddemand‐side changes■ System stabilization on large‐scale introduction ofrenewable energy

・Development of next generation power distribution network system
・Development of power system stabilization technology in trunk
transmission system assuming high penetration of renewable energy
・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

Utility management●Ensuring consistency of power system reforms
and energy measures
・Issues in institutional design of the electricity system reform
・Consideration of countermeasures against large‐scale introduction ofrenewable energy
・Structural analysis of energy and electricity demand■ Next‐generation power distribution system technology
compatible with greater activity in demand region

Renewable energy

・Power quality preservation and enhancement for distribution systems
with advanced customer devices
・Development of simulation methods for distribution‐system transients
based on an electromagnetic transient program●System stabilization on large‐scale introductionof renewable energy●Forming, maintaining and update power
distribution facilities▽Development of next generation power distribution network system▽Development of power system stabilization technology in trunk
transmission system assuming high penetration of renewable energy▽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▽Consideration of countermeasures for large‐scale introduction ofrenewable energy

・Development of evaluation technology on lightning risk management
and fault current countermeasures for distribution systems
・Diagnostic technology for power distribution equipment●Expanded introduction of biomass and geothermal
power generation
・Development of innovative technologies for promoting the introductionof geothermal power▽Development of technology for expanded use of biomass in thermal power generation●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
・Establishment of protective measure technologies against wind andsnow damage of overhead transmission and 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

Common cross-cutting ﬁeld
●Overall optimization through supply/demand
coordination
・Optimization of advanced power supply and demand management●Common technology for application in diverse
ﬁelds
・Development of advanced sensing technology for power plantcomponents
・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●：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
times)

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Major Research Results-1

Major Research Results–1

Thermal-Hydraulics in Reactor Core Under Fuel
Uncovering Condition of Rod Bundle
Contributions for improving the safety of nuclear reactor with thermal-hydraulic

Nuclear Power
Generation

Reactivity initiatedaccident (RIA)
Accidents causing thenuclear reactor's output
to increase rapidly due tothe control rod falling or
being projected out andan abrupt reactivity to be
initiated within thereactor.

In order to quantify safety limit for the critical situations such as reactivity initiated accidents (RIA), whereby thereactor power increases rapidly due to the control rod drop of a boiling water reactor (BWR) or upspring of the oneof a pressurized water reactor (PWR), to understand safety margin of a situation where the water level of a nuclear
reactor is falling with explosion of fuel due to an accident out of the design standard, it is necessary to clarify thesurface temperature of the cladding tube and ﬂow/cooling properties of the coolant under near-accident conditions
relevant to pressure and temperature. CRIEPI has developed pulse-type heating technology of fuel-simulated rod
bundle for the situation of RIA and measurement techniques at high time/spatial resolution in the test section underhigh temperature/pressure, in order to clarify thermal dynamics of a nuclear reactor in an accident.

Outline of Results◇ Clariﬁcation of Critical Heat Flux
In order to simulate an RIA, CRIEPI developed a direct electrical heating rod which is able to rapidly heat thefuel-simulated rod bundle and measured the cladding tube surface temperature while gradually changing the heat ﬂux.
As a result of a high temperature/high pressure test, it was conﬁrmed that at the condition beyond a certain heat ﬂux,

Heat ﬂux
An amount of heat thatcrosses per unit of area
per unit of time.

Void fraction
The ratio of the volume ofgas gas-liquid two-phaseﬂow.

the surface of the heated-cladding tube became dried and the surface temperature rose rapidly, therefore the state ofThermal Hydraulics Systems Domain,occurs is deﬁned as critical heat ﬂux (CHF) and it was clariﬁed that the rapidly steam-generated behavior eachexperimental condition by measuring the CHF from atmospheric to high temperature/pressure condition.

◇ Clariﬁcation of the coactive water-level dropping process in a fuel-simulated rod bundle
Regarding the coactive fuel exposure process when the coolant cannot be poured into a reactor core, CRIEPI

Nuclear Technology Research Laboratory
Reactor Internal Flow Visualization Unit X-ray CT/real-time Radiography Device
A device able to visualize the two-phase ﬂow within a mock fuel ssembly in 3D format.

combined X-ray CT imaging and its transmission image with our original void fraction measurement technology,
and devised a predicting equation of void fraction for severe accident analysis to measure the detailed void fraction

Test
specimen

distribution and the time-depended variation of water level.
Detector for RTR

Severe accident

Pressure 7MPa, Inlet ﬂow rate 0.2m/s, Subcooling degree 5K
Temperature continuously rises after
400
the stop of heating fuel-simulated rod
bundle (heat removal limit)

1.4
1.2
Normalized heat ﬂux q’(a.u.)

An accident whichsurpasses the assumptions
made during the safety
design/evaluation process
for a nuclear reactor.

Hiroki Takiguchi

high temperature was maintained even after the stop of the heating (Fig. 1). The minimal heat ﬂux in which this state

1
0.8
0.6

Heat ﬂuxq”
max =1.98MW/m2

380q”
max =1.71MW/m2

360q”
max =1.28MW/m2

340
320

0.4

300

0.2
0
-0.5

280

Cladding tube
surface temperature
0

0.5

1

1.5

2

Central Research Institute of Electric Power Industry

An example of the change in cladding tube surface temperature over time
during an RIA triggered by a control rod falling

FY2016 Annual Report

Rotation

Conceptual diagram of an X-ray CT/real-time radiography device

Verticalmovement

Turntable

Application Examples of Research Results
Aim to increase the reliability of safety evaluations and improve nuclear power plant safety by applying the void ratio prediction equation tosafety analysis in the critical heat ﬂux and fuel exposure processes during an RIA.

260

Time (seconds)

Fig. 1

X-ray
sourceDetector for CT
Cladding tube surface temperature（℃）

An electrical current orelectrical wave that ﬂows
in an extremely short timeinterval.

Thermal portion 310mm

Pulse

16

Nuclear Power Generation

Nuclear Power Generation

A rod or plate-shaped
device which absorbs theneutrons generated
during nuclear ﬁssion of a
nuclear reactor andreduces the nuclear
ﬁssion reaction. The
control rod is eﬀective insuppressing output.

Background

Major Research Results

Major Research Results

Control rod

tests of fuel-simulated rod bundle

References: T. Arai, M. Furuya et al., Multiphase Sci. Tech., Vol. 27, p. 203 (2015)

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Major Research Results-2

Major Research Results–2

Establishment of a Method to Systematically Evaluate
the Activity of Faults in Nuclear
Power Plants, Identify Active Faults and Help Improve Facility Safety

Nuclear Power
Generation

which exist within the power plant site. Even the new standards established after the Great East Japan Earthquake

Active faults◇ Establishment of a fault activity analysis ﬂow

Faults that have been
repeatedly active fromthe new geological age
on w ard s a nd h a ve th epotential to be active inthe future.

Outcrop observation
An observation of places
outside where strata or rocks
are exposed conducted inorder to obtain information on
the stratigraphic relationshipof strata, etc.

include a requirement to identify fault lines which may impact the safety of nuclear power facilities and makedetailed evaluations of fault activity, such as when the latest activity was, the amount of displacement since the lastactivity, etc. CRIEPI has established a method to evaluate fault activity based on the crushing properties of faults
within bedrock and is working to develop a method to evaluate the activity of faults within nuclear power plantfacilities throughout Japan with higher accuracy.

Outline of Results

Regarding the crushing properties of faults within bedrock, CRIEPI established an analysis ﬂow enabling detailed
evaluations, from macroscopic evaluations such as outcrop observation and boring core observations to microscopic
evaluations using electronic microscopes, such as identiﬁcation of mineral damage and distortion along faults. We
applied our analysis ﬂow to an actual nuclear power plant and objectively observed that the faults within the plantsite could not be considered active faults in regards to earthquake resistance (faults for which activity since the Late
Pleistocene period approx. 120/130,000 years ago can’t be ruled out).

Keiichi Ueta

External Natural Event Research Team,
1) Observation and samplingof the fault zone
Fault gouge
Fault breccia
Damage zone2) Identiﬁcation of latest fault surfaces throughhelical X-ray CT, observation of microstructure
through Micro Focus X-ray CT

Helical X-ray CT4) Identiﬁcation of fault
displacement orientation
using a laser microscope

Micro Focus X-ray CT5) Identiﬁcation of most recent
minerals along fault line surfaces
using an X-ray diﬀraction analyzer

6) Identiﬁcation of crushing/distortion ofminerals along fault surfaces using anelectronic microscope

Fault activity analysis ﬂow

Trench survey

（ft）
625

Specimen

Scanning-type electronic Transmission typemicroscopeelectronic microscope

18

Nuclear Risk Research Center3) Identiﬁcation of fault
displacement direction using
a stereo microscope

Helical X-ray CT
A device enabling the detailed, non-destructive, 3-dimensional observation of a specimen by transmitting X rays inside the sample.
Source ofradiation

A survey involving digging
a trench to a depth ofseveral meters to several
dozen meters at a location
where it is believed fault
activity has occurred andclosely observing thestrata in the trench walls
in order to investigate
past activity of active
faults.

Nuclear Power Generation

Nuclear Power Generation

In order to improve the safety of nuclear power plants, it is necessary to appropriately evaluate the activity of faults

After the Fukushima Daiichi
nuclear disaster, the Nuclear
Regulation Authority (NRA)
issued these standards underwhich it is mandatory to
implement countermeasures
for severe accidents andthese regulations specify
stringent safety countermeasures
assuming earthquakes andtsunamis. These standards
must be met in order tooperate a nuclear power
plant.

Major Research Results

Major Research Results

New standards

Background◇ Demonstration of the rationality for conducting fault surveys at nuclear power plants

CT imageBreccia zone
(source rock: siliceous shale)
Fault
gouge zone
(mixed with breccia)

627

Example of results of an observation into
the internal structure of a fracture zone629

The photo in the middle shows theboring core specimen, while the photo to
the right shows the helical X-ray CT
photo of the boring specimen.

631

Breccia zone
(source rock: sandstone)(proto-cataclasite)

Fault gouge zone
Main fault surface

60mm

60mm

Application Examples of Research Results
The fault activity evaluation technique proposed by CRIEPI is incorporated and quoted in documentation for reviews to conﬁrm conformity with
the new standards for nuclear power plants across Japan. It is also utilized to evaluate the activity of faults on a power plant’s site.

As a result of conducting a trench survey and fracture zone analysis of the surface fault ruptures that appeared after
the 2014 Northern Nagano Earthquake and 2016 Kumamoto Earthquake, CRIEPI conﬁrmed the accumulation of
fault displacement and layered makeup of the fault gouge, which is characteristic of active faults, even in thoseareas where active faults weren’t shown in existing literature. From this we clariﬁed it was possible to appropriately

References： CRIEPI TOPICS Vol.18 (2014)

evaluate whether a fault was active or not by conducting a fault survey on a nuclear power plant site.

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19

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Major Research Results-3

Major Research Results–3

Development of a Human Reliability Analysis (HRA)
Guide for the Utilities
Aiming for the appropriate assessment of human error on nuclear power plants
risk evaluation

Background

Human Reliability
Analysis (HRA)

In the probabilistic risk assessments (PRA) of nuclear power plants there is a need to quantitatively assess the

HRA quantitatively andqualitatively evaluates theimpact of human error
probability (HEP) andsafety improvement as
part of probabilistic risk
assessment (PRA).

years, the reliability of nuclear power-related plant equipment is improving, therefore the impact of human error onhuman error probability (HEP) to ascertain the extent that human errors by operators, etc. impact risk. In recent
risk is becoming relatively higher and the importance of Human Reliability Analysis (HRA) is increasing. The HRA
quantitative method (THERP) currently being used in Japan is the method of handling the human error at theprocess of emergency procedure (mainly execution failure). However, in international HRA research trend, themethod (Ex. Decision Tree Evaluation Model) that treats contexts of cognition / diagnosis failure in case of
emergency situation will be becoming the next generation standard methods. CRIEPI is working to create an HRA

Major Research Results

Guide in order to introduce these techniques in Japan. And we are also working on the development of new HRA
THERP（Technique for Human
Error Rate Prediction）
A quantitative assessment
method for human error
probability developed
and published in 1979
with the support of the
U.S.NRC.

methods which focuses on the decision-making process in terms of response during severe accidents, including
situations where there are no clear procedures.

Outline of Results◇ Developing the HRA Guide

Nuclear Power Generation

Nuclear Power Generation

Major Research Results

Nuclear Power
Generation

CRIEPI has established a new qualitative analysis ("Narrative developing") method for HRA based on the conceptthat the occurrence of human error is not random but occurs by the context of cognition and action in theenvironment in which humans (operators). Moreover, we have developed the HRA Guide, in order to apply thisYukihiro Kirimoto

qualitative analysis approach to the quantifying method (a combination of Decision Tree and THERP methods)

Risk Assessment Research Team,currently being used as the standard in the U.S., etc. By using this guide, it is possible to conduct HRA based on

Nuclear Risk Research Center

clear grounds for judgment against the input data from the time of the analysis.

◇ Extraction of problems for development of new HRA method under extreme conditions
CRIEPI applied the HRA guide to the assessment, using the scenario of transporting, installing and supplying fuel to the

Aim to establish the HRA method under extreme conditions

mobile water injection pump for the emergency alternative core spray, and reviewed problems with current quantiﬁcation
methods. As a result, CRIEPI discovered that THERP, which focuses particularly on human behavior as random failure, has
the issue that, if descriptions on the multi-layered nature of operation steps and recovery procedures per individual task
step were lacking, the failure probability was extremely high. CRIEPI aim to utilize the knowledge gained from analyzingthese types of actual severe accident scenario, develop a new quantifying method to respond to human error context andrevised HRA guide under extreme conditions. CRIEPI aim to utilize the knowledge gained from analyzing these types ofactual severe accident scenario, develop a new quantifying method to respond to human error context and revised HRA
guide under extreme conditions. Conﬁguration of an HRA guide using the concept of cognitive / diagnosis failure.

Human Reliability Analysis Guide(HRA Guide)

Application Examples of Research Results
Japanese utilities are considering using the quantifying tool for human error rate being used in the U.S. etc in probabilistic risk assessments forreactor core damage that occurs due to causes intrinsic to the facilities/operational management of power plants. The HRA Guide created by
CRIEPI is anticipated as a tool for ensuring appropriate data is inputted into this quantifying tool.

References： Y.Kirimoto et al.,“Developing an HRA Guide for Japanese Utilities Combining the NRC Narrative Approach with the EPRI HRA Calculator”, A-093, PSAM13

Conﬁguration of an HRA guide using the concept of recognition/diagnosis failure, which is the latest technique

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Y.Kirimoto et al.,“NRRC HRA upgrading, and research plan of HRA method development for extreme condition”SS6-5, PSAM13

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Major Research Results-4

Major Research Results–4

Development of a Strength Assessment Technique for Nuclear
Reactor Pressure Vessel Steel Using Ultra-small Test Specimens
Contribute to the securing of integrity for nuclear reactors through a strength

Nuclear Power
Generation
Charpy impact test

C(T) test(Compact Tension test)
A test which involves
pulling (tensing) a square
test specimen with a crack
to determine the strength
when the specimen isbroken from the tip of thecrack.

BackgroundThe steel used in nuclear reactor pressure vessels (RPV) are embrittled due to the irradiation of neutrons, therefore
it is important to assess whether the steel has suﬃcient strength (fracture toughness) to conﬁrm the integrity of
nuclear reactors after the irraidation. For this reason, every RPV has multiple surveillance specimens installed inside
and the specimens are periodically retrieved and subjected to a fracture toughness evaluation. In order to perform afracture toughness evaluation throughout the entire period of a reactor’s operation, a greater number of test
specimens are required, therefore there is a need for technology to enhance data, such as re-using surveillance
specimens. CRIEPI is developing a fracture toughness evaluation method using an ultra-small C(T) (Mini-C(T))
specimen as small as a person’s thumbnail, making it possible to machine additional specimens from the broken

Major Research Results

Major Research Results

Breaking a squarespecimen with a notch in it
through high-speed impact
to assess the specimen’s
toughness based on theenergy needed for the
break.

assessment eﬀectively utilizing surveillance specimens

halves of the surveillance specimens spent for a Charpy impact test.

Outline of Results

The Master
Curve Method

Several Mini-C(T) specimens can be machined from the broken halves of a surveillance specimen used as a Charpy

A type of fracture toughness
evaluation characterized byexpressing the dimensional
dependency of thespecimen in a formula.

specimens and the Mater Curve method is equivalent to that by larger C(T) specimens. As such, it has become

impact test specimen (10 × 10 × 55 mm) (Fig. 1). CRIEPI conﬁrmed that fracture toughness evaluated by Mini-C(T)Masato Yamamoto

possible to obtain additional fracture toughness data coexistent with the Charpy impact test currently being used.

Vessels/Reactor Structures Unit,

Nuclear Power Plant Maintenance Research Team◇ Conﬁrmation of potential for application in weld metal materials
A pressure vessel is made by welding steel plates (base material) together. CRIEPI clariﬁed that Mini-C(T)Fracture toughness evaluation device
A device that pulls a specimen with a crack in its center in a vertical direction to assess the strength when the specimen breaks fromthe crack (fracture toughness).

specimens could also be used to assess the fracture toughness of weld metal, even though the weld metal
potentially has material variability due to the heating history during the weld process. We conﬁrmed that theassessment results were consistent among multiple institutions both in Japan and overseas.

Charpy impact test of a nuclear
reactor pressure vessel

Broken halves ofSurveillance
specimen

Photo of the C(T) specimen
From the top: Mini-C(T) specimen, 0.5 inch C(T)specimen, 1 inch C(T) specimen. The rectangular
object shown in the bottom left is a surveillance
specimen for a nuclear reactor pressure vessel.

Nuclear reactor pressure vessel
surveillance specimen(10 × 10 × 55 mm)

Application Examples of Research Results
Mini-C(T) specimenmachined from Charpy
broken halves(4 × 10 × 9.6 mm)

The fracture toughness test and evaluation method using Mini-C(T) specimens developed by CRIEPI are contributing to securing the integrity of
nuclear reactors in various ways, such as being standardized as Japan Electric Association Code JEAC4216-2015“A test method for thedetermination of ferritic steel fracture toughness reference temperature (T0).”

Reactor pressure vessel

Fig. 1 Concept image of Mini-C(T) specimen retrieval

Reference： Masato Yamamoto, Naoki Miura,“Applicability of Miniature-C(T) Specimen for the Master Curve Evaluation of RPV
Weld Metal and Heat Aﬀected Zone,”ASME 2016 Pressure Vessels and Piping Conference, PVP2016-63762, (2016)

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Nuclear Power Generation

Nuclear Power Generation◇ Development of a technique for fracture toughness evaluation utilizing Mini-C(T) test specimen

2–2.

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Major Research Results-5

Major Research Results–5

Establish a Radiological Protection System with
Scientiﬁc Rationality
Reﬂect to the Radiological Protection Standards and Streamline Radiation-related

Nuclear Power
Generation

Work

Background

Emergency exposure
situations

After the Fukushima Daiichi nuclear disaster, diﬀerent radiation exposure situations, including emergency, existing

Unforeseen situations
that may require
emergency and long-term
protection measures.

chronologically. Radiological protection standards are separately stipulated corresponding to those exposure(post-accident) and planned (normal situation) exposure situations were mixed both geographically andsituations, however the current standards require adjustment as they do not suﬃciently consider the balance
between mixed radiation exposure situations. Moreover, there is lively international debate regarding the treatment

Situations in which exposure
existed prior to decision oncontrol being conducted.

transporting goods from radiation controlled area) and 2) establishing a protection system based on the new

Planned exposure
situations
Situations in which theprotection measure wasplanned in advance andthe scale and scope of
exposure can be rationallypredicted.

adjustment of the current standards for radiation management of nuclear power operators (standards forradiation risk concept of covering non-cancer eﬀects applicable to both planned and emergency situations.

Outline of Results◇ Formulation of guidelines
CRIEPI has developed a surface contamination dose evaluation model, which can estimate the radiation dose of the

ICRP(International Commission
on Radiological Protection)members of the public due to the reuse of surface contaminated material, by classifying the three categories of

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

contaminated goods considering the balance between each exposure situation (emergency, existing and planned).

handling objects by hand, handling objects at close proximity and handling objects at a distance (bottom ﬁgure on

A self-governing bodyestablished under theUnited Nations for the
purpose of promoting
scientiﬁc and technicalcooperation regarding thepeaceful utilization of
nuclear power.

Engaging in eﬀorts to establish a radiological protection system based on the new concept of“Minimum Provable Risk”.

CRIEPI proposed Minimum Provable Risk (MPR) (Fig. 1) as a new indicator able to prove epidemiological

Surface size
0.1m2

detectability in radiation risk evaluation. By using the life table method with Japanese statistical data of population

Surface size
Distance1m2
0.2m

Surface size
10m2

Distance
1m

and annual mortality rate for cause of death, we have calculated the lifetime mortality risks and their variations forcirculatory diseases and cancer. Then based on these results, we have estimated the MPR for circulatory diseases(MPR N ) and for cancer (MPR C ), respectively. The result quantitatively indicated that, compared to cancer,
suﬃciently suppressed by the current standards that aim to protect against radiation risks related to cancer.

3 types of representative exposure scenarios

MPRN

Lower limit curve for proving
the radiation eﬀect

5 through 7
Provable
Non-provable

MPR

It is diﬃcult to fully compensate the diﬀerence of
background lifetime risks in the exposed/non-exposedgroups, therefore in such cases, the minimum risk able
to be proven does not decrease, even if the numberof subject is made larger.

Fig. 1 Deﬁnition of Minimum Provable Risk (MPR)

Central Research Institute of Electric Power Industry

FY2016 Annual Report

The MPR for
circulatory diseases is
5 to 7 times higher
than that for cancer.

1) Handling
objects by hand2) Handling objects
at close proximity

3) Handling objects
at a distance

Application Examples of Research Results
We will aim for our guidelines to be reﬂected in the international standards (clearance standards) currently being examined by the IAEA
(International Atomic Energy Agency). We will make presentations to stress that the circulatory disease will relatively be diﬃcult to be proven as aeﬀect of radiation exposure in international meetings in order to reﬂect the results to the next ICRP’s main recommendations.

MPRC(Reference)
Risk level of current
protection standards

1

CancerExternal exposure
Inhalation exposure

Oral intake
Skin exposure

circulatory diseases had a larger MPR (Fig. 2). This clariﬁed that radiation risks related to circulatory diseases are

Number of subjects

24

Nuclear Technology Research Laboratory

Protection Standardization Committee of the Japan Health Physics Society.

MPR

IAEA
(International Atomic
Energy Agency)

Radiation Safety Research Center,

This proposal was adopted into the guideline as quantitative- and scientiﬁc-based standards by the Radiological

Lifetime mortality risk (%)

A table expressing theprobability of people ofvarying ages becoming
deceased within one year’stime and the average
number of years theindividual is expected tolive, etc. using indicatorssuch as mortality andaverage life expectancy.

Michiya Sasaki / Takatoshi Hattori

right-hand page). Utilizing this evaluation model, we have prepared a proposal for guidelines on moving out of◇ Establishment of a New Radiation Risk ConceptLife table

Nuclear Power Generation

Nuclear Power Generation

cancer-related eﬀects by the ICRP. In response to this situation, CRIEPI is 1) formulating academic standards for the
Major Research Results

Major Research Resultsof non-cancer eﬀects, such as circulatory diseases, since radiation risk has primarily been deﬁned based on
Existing exposure
situations

Circulatory
diseasesFig. 2 Comparison of Minimum Provable Risk (MPR)

References： Ogino et al., J. Radiol. Prot., Vol. 36, p. 865 (2016)
Sasaki et al., Jpn. J. Health Phys., Vol. 51, p. 167 (2016)
Ogino et al., Appl. Radiat. Isot., Vol. 67, p. 1282 (2009)

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Major Research Results-6

Major Research Results–6

Development of a Highly-Reliable Quality Control
Technique for an Engineered Barrier Material
Contributing to the construction and operation of low-level radioactive waste

Nuclear Power
Generation
Pit disposal

The engineered barrier in the pit disposal and the sub-surface disposal facilities for low-level radioactive waste will
be constructed by using clay (bentonite) in order to prevent nuclide migration. An important function of thebentonite is low permeability. Low permeability of the bentonite is mainly determined by the montmorillonite
content, because the montmorillonite has a characteristic to swell by absorbing water. In order to ensure safety inthe disposal, CRIEPI is promoting research to realize the highly-reliable quality control of the engineered barriermaterial through precise measurement of the montmorillonite content of bentonite.

Outline of Results◇ Comparative veriﬁcation of testing methods for the montmorillonite content
The montmorillonite content is evaluated by the methylene blue (MB) adsorbed on the bentonite, and the simpliﬁed
method which is so-called“spot method”has been frequently used in practice. The spot method has a possibility of
individual error due to visually determination of the amount of MB adsorbed. CRIEPI performed the MB adsorption

Shingo Yokoyama / Yasutaka Watanabe

test by the spot method using uniﬁed equipment for testing, then compared the experimental result to that of“theNuclear Fuel Cycle Backend Research Center,

spectrophotometric method*”. This comparison clearly showed that the results of both methods were practically

Civil Engineering Research Laboratory

corresponded. Therefore the spot method can provide reliable data with high accuracy if the equipment andprocedures were uniﬁed.
*A method to quantify the concentration of MB using absorbance. In compared to the spot method, it is not easy to frequently use thespectrophotometric method in construction sites, because of the cost and setting equipment for testing.

We are working to develop a technique for quality control of bentonite, which is an engineered barrier material.

Backﬁll◇ Technique to collect pure montmorillonite from the bentonites

Cover soil

Low permeability layer(bentonite-based material)

As using a centrifugal separator, etc., CRIEPI established the method to collect the montmorillonite with high purity
by removing accessory minerals contained in the bentonite. Measuring the amount of MB adsorbed on both the

Low permeability layer (bentonite-based material)collected montmorillonite and the bentonite lead to evaluation of the montmorillonite content of the bentonite moreaccurately.

Waste

Waste

Halo
Spot
Colourless moist halo

Amount of MB adsorbed(mmol/100g)

The methylene
bl ue t ha t is no t
adsorbed appears
as a haloNa-type montmorillonite
Ca-type montmorillonite

200
180
160
140

Saturated adsorption
obtained with thespectrophotometricmethod

120
100
80
60
40

Pit disposal
Practically the samevalue for methylene
blue adsorbed asthat obtained by the
spot method on thesame sample

20
0

0

20 40 60 80 100 120 140 160 180 200 220

Amount of MB added (mmol/100g)

Spot method(Using a ruler to visually measure the widthof the halo formed when methylene blue
solution mixed with clay put on a ﬁlter
paper)Waste
Low diﬀusion layer(cement-based material)

Bedrock220

原子力発電
NuclearPower
Generation

The disposal method of
low-level radioactive wastewith a relatively highradioactivity concentration.
The waste is disposed in atunnel or silo-like structure
made of concrete at a
depth of 50 to 100 meters
underground.

原子力発電

Nuclear Power Generation

Sub-surface disposal

Background

Major Research Results

Major Research Results

The disposal method of
low-level radioactive wastewith a relatively low
radioactivity concentration.
The waste is disposed in an
artiﬁcial structure such as aconcrete pit in approx. 25
meters underground.

disposal facilities

Results of the methylene blue adsorption testby the spectrophotometric method

Waste

Sub-surface disposal

Conceptual image of using bentonite in low-level radioactive waste disposal facilities

Application Examples of Research Results
The veriﬁed method for the measurement of montmorillonite content contributes to the standardization of the spot method as a testing methodthat can be utilized in practice. Moreover, the results of this research, including the technique to collect the pure montmorillonite, lead to progressof the quality control of the bentonite in order to keep safety to construct and operate the radioactive waste disposal facilities.

References： Watanabe et al., Goldschmidt Conference 2017（Paris）

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Major Research Results-7

Major Research Results–7

Proposal of a Life Assessment Method for High Chromium
Steel Pipe Considering Individual Material Properties
C ont r i but i on t o t he i mmpp r o ve me n t o f p ip e ma in t e n a n ce a n d ma n a ge ment in

Thermal Power
Generation
9Cr steel

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

Background
With the aim of improving thermal eﬃciency, thermal power plants built in recent years have had higher steam
temperature; therefore 9Cr steel, which has higher strength than the material used to date, is widely used. 9Cr steel
is an excellent material, however if used at a high temperature for a long period of time, creep damage graduallyprogresses in the pipe welds. Thus, the remaining life must be assessed. In response, CRIEPI has performed creep
tests on welded pipes and by predicting the life of the pipe based on the statistical analysis of this vast amount ofdata (99% reliability lower limit), each thermal power plant is operating with suﬃcient consideration to safety.
CRIEPI is developing a higher accuracy life assessment method through conducting various studies into pipes
actually used for extended periods of time and the detailed analyses thereof.

Major Research Results

Major Research Results

A type of high chromium
steel which contains 9%
chromium and is a ferritic
heat-resistant steel. Heat
resistance temperature is
600 - 630℃.

high-eﬃciency thermal power plants

Outline of Results◇ Variation in metal with creep crack and related factors

Thermal Power Generation

used for extended periods of time, we observed

The blue portions indicate vanadium
nitride-based precipitates. Large ones
are counted as one.

variation of the creep life in the welds of 9Cr steel

Thermal Power Generation

By analyzing test data of systematic creep in pipes

1.5

and identiﬁed that this variation depended on theStandardized life of each pipebase material

creep life of 9Cr base material. In order to clarify
the controlling factors of the base material life,
CRIEIPI used a state-of-the-art spherical aberration
corrected transmission electron microscope toanalyze a vast quantity of samples and obtained
statistically highly-reliable data of ﬁne precipitates
for the ﬁrst time. As a result, we realized there iscorrelation between the life of 9Cr base material
and the number density of vanadium nitride-based
precipitates (Fig. 1).

400nm

Masatsugu Yaguchi / Susumu Yamada

400nm

Structural Materials Sector,

1.0

Materials Science Research Laboratory
Spherical Aberration corrected transmission electron microscope
An apparatus is able to quantitatively and statistically investigate the dispersion of ﬁne precipitates in high chromium steel.

0.5

0.0
0.0

5.0

10.0

15.0

Number density of vanadium-nitride-based precipitates（μm-2）

Fig. 1 Controlling factors of creep life in 9Cr base material
The results of microstructural analyses performed on
various used 9Cr base materials show a correlation withthe creep life only when the various types of precipitates
contain vanadium nitride.

◇ Proposal of a creep life assessment method based on a microscopic sample considering theunique material properties of each pipeso small there would be no impact on the safety ofthe pipes, and conducting an analysis of ﬁne
precipitates of 9Cr pipe base material as well as a
creep experiment. By doing this, it will be possible
to assess the life of welds for each speciﬁc pipe
from the results of a properties assessment of the
9Cr pipe base material using a microscopic sample(Fig. 2).

Stress [MPa]200

CRIEPI proposed collecting a microscopic sample

10mm

9Cr weld joints, 600℃

100
70

Test data
Average properties
99% lower reliability limit

50
40
103

104

Fracture time [h]Microscopic sample(Thickness: 0.5 mm)
105

Microscopic sample forMaterial properties equation
observational analysis and creep tests
for 9Cr weld joints
Material properties
equationStressevaluation

Use 99% lower
reliability limit

Estimation of material properties
using a microscopic sample

Current life assessment
methodFY2016 Annual Report

welds to suit the speciﬁc creep properties. By referring to this assessment result, it is anticipated that the maintenance and control of pipes inhigh-eﬃciency thermal power plants will be performed with higher validity.

High accuracy assessment
considering actual circumstances

Proposed life assessment
methodFig. 2 Comparison of the current vs. proposed life assessment methods

Central Research Institute of Electric Power Industry

By applying microscopic sample assessment technology to 9Cr pipe base material, it will be possible to conduct life assessments of each pipe’s

Use values speciﬁc
to each pipe
Safe-side
assessment

28

Application Examples of Research Results

References： Yaguchi et al., ASMEPVP2016-63316 (2016)
Nagai et. al, CRIEPI Report Q14002 (2014)

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Major Research Results-8

Major Research Results–8

Development of a Measurement Device for the Rapid
Measurement of Boron Content in Coal Ash

Thermal Power
Generation

Every year, Japan’s coal-ﬁred power plants emit approximately 95 million tons of coal ash, of which 60% is used as
cement material. However, with no signiﬁcant increase in demand on the horizon and the limited availability ofspace for coal ash landﬁll, there is a need to develop new applications other than as cement material, such as
material for artiﬁcial ground (Coal Ash Mixed Material, CAMM), etc. As part of eﬀorts to expand the eﬀective
utilization of coal ash, CRIEPI is developing a technique to ascertain the content of trace elements in coal ash whichpose a risk of environmental impact in order to appropriately evaluate the environmental safety when CAMM is
used.

Environmental safety

Outline of Results◇ Development of the simple and rapid boron detector for coal ash

Boron

CRIEPI developed a neutron boron gauge that measures the boron content in coal ash by utilizing boron’s property

One element stipulated in
the Soil Environment
Standards. Used in
fertilizer, heatproof glass,etc.

of speciﬁcally capturing thermal neutrons. This device is capable of measurement without pre-treating the sample,
therefore it is extremely simple and rapid than the conventional method, which required pre-treatment such as wet
digestion method with strong acid, etc. This measurement device has been commercially sold by manufacturers

Hiroyuki Masaki / Seiji Inoba

from May 2017.

Environmental Science Sector,

Environmental Science Research Laboratory◇ Establishment of a technique for the evaluation of environmental safety of CAMM
Lysimeter

In order to evaluate the environmental safety of using CAMM as subgrade or backﬁll, CRIEPI has established a

A large tank ﬁlled withsoil, etc. capable ofevaluating the pore water,
element mobility, etc. of
soil.

full-scale test method utilizing a lysimeter. By applying this test method, it is possible to evaluate the elution of

Lysimeter Testing Unit

Utilizing for the full-scale evaluation of coal ash mixture elution properties

elements from CAMM for a variety of forms and applications in the actual form it is in.

Neutron source Coal ash sample(internal)

Signal processing device

Measurements using the neutron boron
technique [mg/kg]

Water collection pipe

2000

100mm

Proportional counter
tube

0.3m

Soil layer

0.5m

Coal ashmixture

0.2m

1500

0.5m

Schematic of a lysimeter interior

1000

Moderator

Water spray: 11 mm/day

A lysimeter makes it possible to observe the migration
behavior of elements in soil as is by simulating theactual environment CAMM is utilized in. The
tank-shaped object to the left of the person in theabove photo is the lysimeter.

500
0
0

500

1000

1500

2000

Measurements using
the conventional technique [mg/kg]

Comparison of the appearance of the neutron boron gauge
developed by CRIEPI and the conventional technique
The coal ash sample is irradiated with thermal neutrons and the boron content is calculated from the number ofthermal neutrons captured. In measurement of boron in coal ash using our developed detector, because
pre-treatment is not required, the measurement time is extremely reduced from two days to ﬁve minutes.
Moreover, the measurements obtained using the conventional technique and this device are in good agreement,
indicating that the neutron boron gauge can replace the conventional technique.

Elution

Safety with regards tohealth impact on humanst h r o u g h s o i l ,groundwater, direct
consumption etc. in linewith utilization of recycledmaterials, etc.

Pore waterat 1.0 m
depth

0.5m

Pore waterat 1.5 m
depth

0.5m

Groundwater level 2.0 m

Sandy soil

Aquifer

Aquiferleachate

Application Examples of Research Results
The neutron boron gauge developed by CRIEPI is being utilized for the advance conﬁrmation of coal ash properties by electric power companies.
Furthermore, the environmental safety evaluation for CAMM will be utilized in the ﬁeld and reﬂected in the design guidelines published by theJapan Society of Civil Engineers.

References: Masaki et al. CRIEPI Report V15008（2016）
Masaki et al. CRIEPI Report V14003（2015）

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31

Thermal Power Generation

Thermal Power Generation

A solidiﬁed mixture
comprising of coal ash
mixed with water,
cement, soil, etc. It isavailable in a variety offorms to suit the
speciﬁcation requirements,
including sand, gravel orlumps.

Major Research Results

Major Research Results

Coal Ash Mixed Material

Background

2–2.

2–2.

Major Research Results-9

Major Research Results–9

Proposal of a Gas Turbine Power Generation Technology
Contributing to Maintaining Supply/Demand Balance
Upon High Penetration of Variable Renewable Energy
Thermal Power
Generation

Gas Turbine Combined
Cycle (GTCC)
A power generation
method combining gas
turbine and steam
turbine.

next-generation gas turbine combined cycle (GTCC).

Background
The high penetration of variable renewable energy, such as photovoltaic energy, has been proposed as a measure
to signiﬁcantly reduce CO2 emissions. The output of photovoltaic energy production ﬂuctuates greatly depending on
the weather, and the amount of power generated decreases rapidly at sundown, which is precisely when power
consumption rapidly increases. One important issue key to achieving stable power grid operation is maintaining thebalance between supply and demand, which changes from time to time. NEDO (New Energy and Industrial
Technology Development Organization) is promoting a study into higher performance gas turbine combined cycle

Major Research Results

Major Research Results(GTCC), which has high eﬃciency and excellent mobility, therefore seen as a promising means to solving this issue.
CRIEPI is developing a next-generation GTCC, which is one of NEDO’s project.

Outline of Results◇ Clariﬁcation of technical issues for next-generation GTCCCRIEPI has used plant dynamic analysis to clarify ﬂuctuation in temperature and pressure that occurs in astability through unsteady numerical analysis. With consideration to these factors which aﬀect GTCC, we has
established GTCC target performances (shorter start-up time, improved ramp rate, lower minimum output,
improved partial load eﬃciency) to be achieved by the year 2030 and has identiﬁed the concrete technologicalThe established 2030 GTCC target performances and the main technologicaldevelopment issues concerning their realization
Start-uptime

Target performance
Large-capacity
GTCC: 100 MW
and above（）（Reference）
Current performance

A tool able to simulate
supply/demand operationfor each power source,
storage device, etc.
considering theuncertainty of renewableenergy output (operationof power plants tobalance supply anddemand).

10 min60 minRamp rate

20%/min5%/minMinimum
output10％50％◇ Eﬀects of next-generation
GTCC introduction
Assuming the future supply/demand status
predicted with the high penetration ofvariable renewable energy, CRIEPI has
tentatively calculated the eﬀects ofnext-generation GTCC with the target
performances on supply/demand operation

50% load
eﬃciency
(LHV)

56％

55％

thermal units. This clariﬁed that operation
costs of thermal power generation would be
reduced (Fig. 1).

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FY2016 Annual Report

Photovoltaic power generation simulation system
A system to analyze the behavior of the power grid when the grid power source is replaced with photovoltaic power generation.

②Device control technology able tomaintain stable operation evenduring times of abrupt load variationand dynamic properties
evaluation/numerical analysis
technology to support such control
technology③High performance cooling/sealing
technology to maintain high partial
load eﬃciency

80％
60％
40％

Amount of generated powerby each power source for Fig. 1.
100％

84％

20％
0％

GTCC performance was improved, it would

variable renewable energy even with smaller

62％

Fig. 1Engineering Research Laboratory

Energy Innovation Center

100％

developed by CRIEPI. This conﬁrmed that, ifbalance upon large-scale introduction of63％①Evaluation during times of heatfatigue and high-durability material
technology

Technology Sector, Energy

Digital Transformation Unit,

Example of technologicaldevelopment issues

120％

using a supply/demand operation simulator

be possible to maintain supply/demandRated
eﬃciency(LHV)

Advanced Thermal Power

Isamu Watanabe

Amount of generated power［%］Table 1

Supply/demand
simulator

Kazunori Watanabe

development issues (Table 1) and issues regarding popularization in order to realize these.

100％

13％

14％

19％

16％

18％

21％

PV/Wind power

8％
7％
5％

8％
7％
5％

Coal

29％

29％

Current performance(Year 2030)

Target performance(Year 2030)

90％
80％
70％
60％
50％
40％
30％
20％
10％
0％

LNGCC
Biomass
Geothermal
Hydropower
Nuclear power

Application Examples of Research Results
As we have quantitatively demonstrated that next-generation GTCC is eﬀective towards reducing operation costs and contributing toCurrent performance(Year 2030)

Target performance(Year 2030)

Example of eﬀects on reducing operation costsof thermal power generation equipmentwith future power source composition
・Targeting the Kyushu area
・Refer to the right page for the amount of generated
power (%) for each power source.
・Transient stability and frequency stability of thepower grid are not taken into considered.

supply/demand operation, we will aim to reﬂect our ﬁndings in national polycies, etc. as part of eﬀorts to embody technological development. We
will also proactively support the popularization of the developed next-generation GTCC so that it may be used by business operators.

References： 2016 NEDO Report“Investigative Research Relating to the Role of Thermal Power Generation in Electric Power Grid Stabilizationin the Context of High Renewable Energy Penetration and CO2 Reduction due to Improved Gas Turbine
Load Fluctuation Absorbance Capacity”(2017)2014-15 NEDO Advanced Research“Research and Development of Advanced Gas Turbine for the Firming Grid in the Renewable Energy Age”
Program for Energy and Environmental(2016)
Technology Results Report

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FY2016 Annual Report

33

Thermal Power Generation

Clariﬁes changes inproperties which varyover time, such astemperature and pressure
in gas turbines.

GTCC plant upon rapid start-up and rapid load ﬂuctuation as well as clarify the impact on combustion

Operation cost［%］Dynamic analysis

Thermal Power Generation

Participating in a national project to promote technological development of

2–2.

2–2.

Major Research Results-10

Major Research Results–10

Development of Eﬃcient Measurement Method for Water
Turbine Vane Thickness in Hydroelectric Generators
Reducing labor required for measurement tasks during inspections

Hydropower
Generation

Background
The thickness of water turbine vanes in hydroelectric generators can decrease due to the penetration of sand, clay,
etc., therefore measuring the thickness of these vanes is important in determining the timing of repairs and renewal.
However, the multi-point measurement method using Vernier calipers performed during inspection requires time andeﬀort, and a cross-sectional proﬁle cannot be obtained easily due to this technique being point measurement. In
order to overcome these issues, CRIEPI is engaging in the development of a technology enabling eﬃcient

Outline of Results◇ Development of a technique to measure cross-sectional proﬁles of water turbine vanes combining
two lasers and cameras
Line laser
A laser that projects a line
rather than a point. The light
projected for the vane will
curve to reﬂect the vanecross-sectional proﬁle.

CRIEPI developed the below measurement technique after investigating the shape of the water turbine vane andthe current inspection process. By projecting two small line lasers on the vane (one each on the front and back of
the vane) and photographing either face using two small cameras, a laser projection image expressing

Hydropower Generation

Hydropower Generation

Major Research Results

Major Research Results

measurement of water turbine vanes in a reduced-thickness state during inspections.

cross-sectional proﬁle is obtained. With image processing using the respective positions and angles of the lasers andcameras, a three-dimensional cross-sectional proﬁle image is obtainable. This has made it possible to conveniently
and eﬃciently measure the cross-section proﬁle of the vane tip, for which measurement had been diﬃcult up until

Chikahito Nakajima

now due to space conﬁnements.

◇ Prototyping a cross-sectional proﬁle measurement device and evaluating accuracy of thickness
measurement through experiment
CRIEPI used line lasers and small, high-deﬁnition cameras to prototype a measurement device such as that shown inDigital Transformation Unit, Energy Innovation CenterWe are working on technological development to enable measurement of a water turbine vane in a reduced-thickness state based onimages captured using line lasers and small cameras.

the ﬁgure below and evaluated the accuracy of cross-sectional thickness measurement when this measurement
technique is actually applied to a water turbine vane, etc. As a result, we noted the potential of this approach for
thickness measurement; with the average error for thickness measurement values using a specimen as 0.14 mm(standard error = 0.05 mm) and the average error when measuring the vanes of an actual turbine or vane model
also being 0.14 mm.

Camera 2

Camera 1

Impeller of a Francis turbine (rotating portion)(Excerpt from Kansai Electric Power’s oﬃcial website)

Water turbine vane modelLine laser 2

Application Examples of Research Results

Projected laserThis measurement technique will enable a signiﬁcant reduction in the cost of inspections of hydropower plant equipment. Moving forward, we will
aim for the practical realization of this measurement device and promote its utilization in power plants.

Line laser 1

Measurement device prototype

Example of a cross-sectional proﬁleobtained from a vane model
References： Nakajima et al. CRIEPI Report C16007 (2016)

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2–2.

2–2.

Appropriately evaluating the necessary capacity of the synchronous generator

Power supply-demandbalance

Many studies of resulting impacts on power system in regard to the extent of photovoltaic (PV) and wind turbines

Power supply is balancedwith demand to keep thepower system frequency.
In the situation thatpower supply-demand isimbalanced, the powersystem frequency would
be changed.

what the operation to limit synchronous generator and PV/WT generation to a certain ratio is carried out to keep

(WT) generation in Japan are focused on the balance of power supply-demand. In overseas, there are examples
power system stability under a power system fault condition. On the other hand, sometimes transient stability
determines the capacity of system operation in Japan, therefore we are working on development for transientstability evaluation method.

Synchronous generator
Many synchronousg e n e r a t o r s a r einterconnected to a powersystem. AC voltage is
generated due to theelectromagnet rotation
inside the synchronous
generator. Furthermore, thepower system frequency isderived from rotation speedof the electromagnet. Thus,
power system stability isenhanced by controllingmagnetic force androtation speed of theelectromagnet .

Outline of Results◇ Proposal of eﬀective evaluation index to keep transient stability
Transient stability is inﬂuenced by following factors when PV/WT is introduced to a power system.
・Transient stability is improved with the apparent load reduction due to PV/WT generation.
・Transient stability is declined with decreasing synchronous generator capacity due to reduced inertia and reduced
ability to keep power system voltage.

Yuji Hanai / Keisuke Shirasaki

We proposed new evaluation index "α" which means the ratio of decreasing synchronous generator capacity inElectric Power System Sector,

exchange for non-synchronous generation to keep transient stability. In addition, it was found out that transient

System Engineering Research Laboratory

stability could be kept by setting the "α" to 50% or less regardless of PV/WT generation using the IEEJ WEST
10-Machine Model.

Power system simulator
Simulates the devices that conﬁgure a power system using a small analog model and reproduces various grid phenomena.

Transient stability
Transient stability is theability to recover fromunstable state immediately
even if a power systemfault occurred.

◇ Analysis of impact on supply-demand operation
Supply-demand operation simulations was conducted to evaluate impacts of ensuring generation capacity for powersystem stability. A constraint using the index "α" was newly formulated, and the constraint was applied to oursimulation tool "Demand and Supply Operation Simulator". The results indicates that a decrease in "α", that is anincrease of required capacity, induces increases of operation costs and CO2 emissions (Fig.2) as well as additional
PV/WT output suppression.

The element to consider
decreasing of synchronous
generator capacityα=G0 － GG0

The element to consider
increasing of PV/WT
generation

PG + PRES
× 100［％］PRES

PRES ： PV/WT generation
PG ： The generation of the synchronous generator
G0 ： Synchronous generator capacity before
PV/WT introduction
G ： Synchronous generator capacity after
PV/WT introduction
As synchronous generator capacity decreases, the"α" tends to increase.
α ＝ 0% → It means that synchronous generator
capacity is equal before and after PV/WT
introduction.
α ＝ 100% → It means that PV/WT generationand stopped synchronous generator
capacity are equal.

Fig. 1 Deﬁnition of the“α”

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FY2016 Annual Report

120％

Thermal power plant operation cost
(fuel cost + start-up cost) (%)
Thermal power plant CO2 emissions (%)

115％

115％

108.6％

110％
105％
100％

120％

102.4％

103.8％

110％

106.1％

105％

100.0％

100％
95％

95％
90％

115％

100.0％

100.7％

101.3％

102.4％

103.5％

107.0％

α=100％ α=60％

α=50％

α=40％

α=30％

α=0％

CO2 emissions［％kg-CO2］

Renewable Energy

BackgroundRenewable Energy

er

for contributing to power system stability

Operation cost［％yen］

Major Research Results

Renewable
EnergyMajor Research ResultsαMajor Research Results–11

Proposal of Evaluation Index of Power System Stability
with High Penetration of Renewable EnergyysMajor Research Results-11

90％

Fig. 2 Results of an analysis simulation of
impact on supply-demand operation
A comparison of operation cost and CO2 emissions in the Kyushu area
based on the long-term energy supply-demand outlook in the year
2030. This comparison is based on α = 100%. Ratio of renewableenergy (PV, WT) introduction is 33% if α=100% and 31.5% if α = 0%.

Unlike inverter-besed power generations ofrenewable energy, all synchronous generatorsconnected to a power grid have synchronizing
power which synchronize the rotation speeds ofthe internal magnets. This feature means that,even if faults in a power system make systemfrequency ﬂuctuated, the synchronous generators
automatically and instantly work to restore theirrotation speeds into those of a normal state.

Features of large-capacity synchronous generators◆Power output control response to frequency variations◆Synchronizing power which uniformize all rotor speeds◆Inertia force which keeps robustness of system frequency
against faults◆Synchronous operations continued even during voltage drop by
a fault◆Voltage control capability of bulk power system

Application Examples of Research Results
When power system operations with maintaining synchronous generator capacity were required from the perspective of power system stability,
this research result would be useful for electric power companies to consider the necessary synchronous generator capacity and appropriate powersystem operation method.

References： Shirasaki et al., The National Conference of the Electric Engineers of Japan 2017 Lecture no. 6-086 (2017)
Hanai et al., The National Conference of the Electric Engineers of Japan 2017 Lecture no. 6-148 (2017)
Shirasaki et al., CRIEPI Report R14013 (2015)

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2–2.

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Major Research Results-12

Major Research Results–12

Establishment of a Communications Platform
Supporting Smart Grid
Mutual Interaction of Applications with Diﬀering Communication Standards toElectric Power
Transmission andDistribution

Platform

With the increasing introduction of smart grids, it is predicted that various applications relating to the coordinationof consumers and power grids and consumer services will grow in popularity. However, the standards forcommunication crucial for power companies to exchange information with consumers and electric equipment diﬀer
between applications, making it diﬃcult to achieve interaction with the current situation. In order to solve thisproblem, CRIEPI is building a communication platform*.
*This research was conducted as joint research with Meidensha Corporation.

Outline of Results◇ Data coordination through integration of various communications
Power distribution
automation
Power distribution
equipment automaticallyjudges transmission
terminal information, etc.
with the aim of control, thusachieving automatic control.

XMPP(Extensible Messaging
and Presence Protocol)
A protocol with XML-based
messages.

The various applications that have emerged from a shift towards smart grids, for example power distribution
automation, demand response and advanced metering, have communication methods determined by diﬀerent
international standards. In response, CRIEPI has built a communication platform by integrating applications with
diﬀerent communication standards via a common API (Application Program Interface) (Fig. 1). Moreover, the lower
level protocol determined by each communication standard adopts XMPP technology which is used for instantmessaging, etc. This allows the information of equipment and systems to be used uniformly, request messages
generated on the sending side to be directly transferred to the receiving side, and makes the mutual utilization ofdata easy.

Hiroyuki Yusa

Communication Systems Sector, System Engineering Research Laboratory◇ Establishment of a Testing System and Performance Evaluation for Communication Platforms
CRIEPI established a testing system for the above mentioned communication platform and evaluated its practicalutility. As a result, we have seen the potential for data communication within a practical timeframe even if a
low-cost communication line and PC-level device are used.

Data Exchange Control Fundamental Tester
Equipped with a communication platform, this tester is utilized for mock communication tests.

Consumer１

Communication standards presumed for
application to advanced metering or IoT

Communication platform supported

Application

Power distribution automation 1

DR1

Advanced metering1

IEEE

XMPP
Communication platform
via a common API

XML(Extensible Markup
Language)

Improved interconnection due to XMPPMMSPower distribution
automation 2

DR2

Advancedmetering2

LTE

XMPP

Protocolconversion

XMPP

A programming language
known for closely
resembling natural
language able to be written
in a text format, making it
highly expandable andintuitive.

Power distribution
automation3

Protocolconversion
HTTP
DR3

Protocolconversion

Advancedmetering3

Communication platform unsupported /XMPP supported

Communication platform unsupported /XMPP unsupported

Consumer2

Consumer3

By using a communication platform via a common API, it has become easy to achieve data coordination
between various applications (power distribution automation, DR, advanced metering) and consumers.
Moreover, if data is communicated in XML format by establishing an XMPP layer in the lower level of eachapplication’s protocol, as is the case with Consumer 3, it becomes possible to send and receive data
between applications without being concerned about communication protocol.

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Standard
802.15.4g
802.11j
Cat.4
Cat.0
Cat-M
NB-IoT

Communication speed
Max. 100 kbps (920-928 MHz)
54 Mbps（4.9/ 5 GHz）
150/ 50 Mbps
1 Mbps
1 MbpsAround 100 kbps

COSEM

Fig. 1 Conceptual drawing of information coordination througha communication platform

38

力流通 and Distribution
Electric Power電Transmission

電力流通Electric Power Transmission and Distribution

Background

Major Research Results

Major Research Results

A program for the common
use of multiple applications.

Contribute to Sophisticated Supply/Demand Coordination

Application Examples of Research Results
It is predicted that there will be increase in smart grids utilizing IT and IoT in power grids. The results of this research will help with previous
day/actual day planning of smart grid consumers, promote utilization of real-time information and is anticipated to make the realization ofsophisticated supply/demand forecasting and control easy.

References： Yusa et al. CRIEPI Report R16001 (2017)
Otani et al. CRIEPI Report R13010 (2014)

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Major Research Results-13

Major Research Results–13

Development of an Identiﬁcation System able to Predict
Lightning Location and Energy at High Accuracy
Contributing to labor-saving regarding patrols and inspections of substations

Electric Power
Transmission andDistribution

and transmission lines

BackgroundThe spread of lightning protection devices for power transmission has seen a reduction in damage to substations
and transmission lines, however it has not yet become possible to eliminate such damage altogether, and patrols

A system with multiple
sensors to detect theelectromagnetic ﬁeld
waveforms generated
from lightning strikes thenestimate lightning
location, time, peakcurrent amplitudes, etc.
based on data analysis.

and inspections of equipment damaged by lightning require a great deal of labor. In order to ascertain the damage
to equipment due to lightning strikes it is necessary to gather information relating to lightning location and lightning
energy, however the conventional Lightning Location System (LLS) was unable to identify location with suﬃcientaccuracy, and did not enable estimation of lightning energy. In an eﬀort to save labor entailed in patrols andinspections of equipment damaged due to lightning strikes, CRIEPI is working on the development of the advanced
Lightning Location System (advanced LLS) able to identify lightning location at high accuracy and estimate

Major Research Results

lightning energy.

Electric Power Transmission and Distribution

Outline of Results

Electric Power Transmission and Distribution

Major Research Results

Lightning Location
System (LLS)◇ Improvement of lightning location identiﬁcation accuracy
Lightning location is generally obtained by capturing the electromagnetic waves generated when lightning strikes
using sensors installed in multiple observation points, then performing data analysis. CRIEPI clariﬁed that the main

Mikihisa Saito

reason for the error in such analyses is the distortion of electromagnetic waves due to long-distance propagation

Lightning and Electromagnetic Environment Sector,(Fig. 1). For this reason, we have developed an appropriate sensor arrangement method to oﬀset error caused byElectric Power Engineering Research Laboratory

waveform distortion and a signal processing method. As a result, the advanced LLS shows potential as being able toidentify lightning location with an error of less than 50 meters, whereas this was unable to be reduced below 250
meters with the conventional LLS.
Waveform is distorted due to impactof ground conductivity

Lightning discharge
current

Measurement of magnetic ﬁelds in an antenna
Frequency range of 750 Hz to 1MHz range at a 100 ns sampling rate for the purpose of electric ﬁeld and magnetic ﬁeld observation.

Electric ﬁeld
strength [pu]

1
0.8
0.6
Observation point-1

0.4

Observation point-2

0.2
0Electromagnetic
-2
-0.2
waves

0

2

4

6

8

Time[μｓ]

Lightning strike point
GroundFig. 1

Observation point -1（30km）

Observation point -2（100km）

Image of the electromagnetic waves changing in accordance with long-distance propagation

When lightning strikes, the current of the lightning bolt discharges ﬂows from the ground into the atmosphere. Inline with this, electromagnetic waves are generated and propagated around the vicinity. The electric ﬁeld
waveform observed at observation points varies due to the eﬀect of ground conductivity during long-distancepropagation.

Lightning strikes Tokyo Skytree

Application Examples of Research Results
This research makes it possible to estimate lightning location and damage to equipment caused by lightning energy, thus helping to identify those
substations and transmission lines in need of patrols and inspections. Furthermore, data relating to lightning characteristics such as lightning
energy can be accumulated and used as a helpful reference when determining equipment speciﬁcations and selecting countermeasure parts, etc. in◇ Estimation of lightning energy

order to establish eﬀective lightning damage preventative measures.

The energy created in a lightning strike (electric charge) is estimated based on electric ﬁeld observation at groundlevel and the charge position inside a thundercloud, however there is a certain degree of uncertainty whenestimating the position of charge inside a thundercloud. CRIEPI clariﬁed through a calculation that the impact of
this uncertainty on estimating electric charge decreased by using electric ﬁeld observation data taken more than 25
km from the lightning strike point. With the advanced LLS, a distance between sensors of around 50 km is assumed
and electric charge can be estimated with high reliability.

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References： Saito et al., CRIEPI Report H16007 (2017)
Saito, CRIEPI Report H15009 (2016)
Saito et al., CRIEPI Report H14007 (2015)

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Major Research Results-14

Major Research Results–14

Development of a Technique to Predict Fusing ofElectrical Wires due to High Current Arc Discharge
Utilizing to prevent breaking accidents of electrical wires through the selection

Electric Power
Transmission andDistribution
Overhead Ground Wire/
Optical Ground Wire

FusingMelting and breaking of
strands of wires due to ahigh current, such as
lightning current or arc
current.

GallopingSee p.48

If the overhead ground wires or composite ﬁber-optic ground wires (OPGW) used in power transmission systems
are struck by lightning, a portion of the strands inside them may occasionally fuse due to the electrical current of thelightning strike, causing the overhead ground wire or OPGW to weaken and break due to tensing up from exposure
to wind, ice, snow, etc., which could lead on to major short-circuit accidents. In overhead power transmission lines,
the same breaking accident may arise due to arc current if the lines short-circuits because of galloping, etc. In orderto prevent this kind of breaking accident, ascertaining the characteristics of wire fusing due to high currents such as
lightning current and arc current is an important issue. CRIEPI is developing a prediction technique using arc tests
and calculation in order to eﬀectively ascertain wire fusing characteristics.

Outline of Results◇ Development of a calculation technique to predict the number of strands of wires that will fuse
due to high energy lightning strikes
CRIEPI has developed a technique to calculate the number of OPGW strands that will fuse by simulating highenergy lightning with direct-current high energy arc. In the calculation, the overall heat transferred from the arc to
the OPGW as well as the heat transfer area are derived, and the OPGW cross-sectional shape is simpliﬁed (Fig. 1,
Fig. 2). This has made it possible to predict the number of strands that will fuse due to the arc electric charge thatﬂows through a strand. In order to verify the validity of our calculation method, we performed a direct-current arc
test and compared the electric charge at which wires fused. The results of this test were in good agreement with thecalculation (Fig. 3). The above technique can also be applied to overhead ground wires, which use practically thesame type of strand in their outer most layer. This technique can also be applied to aluminum conductor
steel-reinforced (ACSR) used as overhead power transmission lines, making it possible to predict the number of
ACSR strands that will be fused due to an alternating-current arc.

An arc is a form of gas
discharge, and arc current
refer to the current createdupon electrical discharge.

Set arc conditions

Set OPGW conditions(Current, duration, polarity, gap length, etc.)(Size, strand type, no. of strands, etc.)

Prediction of overall heattransfer from arc to OPGW

Prediction of heat transfer areafrom arc to OPGW

Arc
OPGW
exposedportionOverallheat transfer
Heat transfer
area

The electric charge (coulomb)at which 3 strands fuse

Arc
600
500

467 469

200
100

79mm2

Steel

0 strands fuse
(Electric charge: 491 coulombs)

84mm2

OPGW cross-section
Fig. 33 strands fuse
(Electric charge: 583 coulombs)

State of strand fusing on OPGW through a direct-current high energy arc test

Comparison with test results

A comparison was made with the results
obtained through a test and through a
calculation for the electric charge (coulomb) atwhich three of the total seven strands would
fuse when subjected to a 24 kA current.

AluminumHigh Power Testing Laboratory
A laboratory to evaluate the short-circuit performance of power distribution equipment such as circuit breakers, transformers, powertransmission cables, etc. applying high current and high voltage.

300

0Calculation technique ﬂow

583 572

Mikimasa Iwata

High Energy Sector, Electric Power Engineering Research Laboratory

400

Calculation of number of fusing strands of OPGW

Fig. 1

Test results
Calculation results

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

An overhead ground wire
is a grounded metal wire
installed above overhead
power transmission lines
in order to prevent thelines from being struck bylightning. A composite
ﬁber-optic ground wire
(OPGW) is an overhead
ground wire with built-in
optical ﬁbers for
information signaltransmission.

Background

Major Research Results

Major Research Results(OPGW)of optimal electrical wires considering lightning current, etc.

Application Examples of Research Results
Prevention of wire breaking accidents by considering lightning current in order to select optimal electrical wires which do not easily fuse for new
installation or replacement.

Actualshape

Fig. 242

Simpliﬁed
shapeSimpliﬁcation of the OPGW
cross-sectional shape

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FY2016 Annual Report

Reference： Iwata et al., 33rd International Conference on Lightning Protection (2016)
Iwata et al., CRIEPI Report H13001 (2013)
Iwata et al., IEEE Transactions on Power Delivery (2013)

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Major Research Results-15

Major Research Results–15

Development of Technology for the Removal ofTransformers Contaminated with Trace PCB
Promoting safe and eﬃcient detoxiﬁcation

Electric Power
Transmission andDistribution

Nationwide estimates indicate that there are several million electrical devices in Japan suspected of being

PCB

contaminated with trace polychlorinated biphenyl (PCB) and these must be dealt with by the deadline stipulated by

A material once widelyused in electrical devices
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 byMarch 31, 2027.

law. As washing technology to extract and detoxify PCB, CRIEPI has developed a heated forced circulation washingmethod for transformers that are no longer in use, and an energized natural circulation washing method fortransformers still in use. Currently, both washing methods are publically acknowledged as PCB treatment
technologies. CRIEPI is also expanding the application of our washing technologies on various electrical devices
and working on development of a more eﬀective detoxiﬁcation technology.
Major Research Results

Outline of Results◇ Expansion of in-use contaminated transformer treatment through introduction of a portion-speciﬁc
energized natural circulation washing method
was a major limitation to the number of transformers to which this method could be applied. As such, CRIEPI
proposed a washing method that focuses on separate portions individually based on results of aninvestigation/analysis into the contamination status of the transformer main unit and its accessories, etc. As a resultof this method enabling washing by transformer portion on an individual basis, it seems likely that the majority ofMotoaki Shirai / Naoya Ohmuratransformers containing 2 kL of oil or more used by power companies will be treatable.
(4)
Bushings(3)
Temperature
sensors(2)
Breathers

Transformer
main unit(1) Tap switchover device
during load states andoil puriﬁer

Environmental Chemistry Sector,

Environmental Science Research Laboratory

A transformer is conﬁgured from a main unit and the portions listed (1) through (4). In somecases, the PCB concentration diﬀers between each portion.
With the current system, energized
natural circulation washing can be
performed only on transformers whichhave no contamination in (4) and a
PCB concentration of 5 ppm or less inthe main unit and all portions from (1)through (3).

In line with the amendment,
regardless of contamination in (4),energized natural circulation washing
can be performed on transformers
which have a PCB concentration of 5
ppm or less in the main unit and all
portions from (1) through (3).

The newly introduced portion-speciﬁc energized natural circulation washing method

This method can be applied to portions for which the PCB concentration inside the insulating oil
has been measured as 5 mg/kg or less even for those portions that are washable but not yet
washed, contaminated portions or unmeasured portions.
The units connect to supply hot oil which is then circulated
within the devices by the attached pump.

◇ Development of a heated forced circulation
washing method for transformers usinglarge amounts of oil
CRIEPI has developed a heated forced circulation

Oil return due to overﬂow
Washing unit

Add washing oil

washing method using two washing units and atransformer pump. We have conﬁrmed eﬀectivenessthrough a veriﬁcation test using an 85 kL oil-capacitytransformer and enabled eﬃcient treatment oftransformers using large amounts of oil.

H P

Washing unit
Drain washing oil

H PHeating heaterand circulation
pump

Circulation
washing

Device being
washedCirculation
P

Delivering oilwith a circulation Large-ﬂow
circulation
pump
pump accessory

Conceptual image of heated forced circulation washingfor transformers using large amounts of oil◇ Demonstration of method for collection of residual oil after washing

Washing treatment site (Yokosuka Area) applying heated forced circulation washing to equipment contaminated withtrace PCBCRIEPI’s transformers contaminated with trace PCB are washed by an organization accredited by the Minister of the Environment.
Overview of the energized natural circulation washing method andheated forced circulation washing method
Energized natural circulation washing method: This method applies
to devices contaminated with trace PCB which are still in use. First,
oil is extracted from the device then uncontaminated washing oil isreplenished, and voltage application is recommenced. The electricalcharge causes the parts of the transformer to generate heat, whichheats up the washing oil, causing it to ﬂow due to the diﬀerencewith the ambient temperature, which washes away the trace PCB.
Heated forced circulation washing method: This method applies todevices contaminated with trace PCB which are no longer in use.
First, oil is extracted from the device then uncontaminated washingoil is replenished, and trace PCB is washed out by heating the oiland causing it to circulate.

Replenish with new oil
Naturalcirculation

Energized natural circulation
washing
Stop voltage applicationof a transformer in use
Oil contaminatedwith trace PCBInternal Remove PCBcontaminated oil
parts

Heating

Commence voltage application
Replenish oil
Replenish with By energizing the transformer, it will generate heatfrom its interior. Oil will ﬂow due to the diﬀerence
PCB-free oilwith the ambient temperature (natural circulation)and the PCB inside will be washed by the oil.
Forcedcirculation

Used transformer

HeaterHeating

Suﬃciently extract
Pump
the contaminatedP
oil inside thetransformer.
Replenish oil and perform heated forced circulation washing
Forcefully circulate oil by heating with a
Heated forced circulation washing heater to wash the PCB inside by the oil.

Application Examples of Research Results
CRIEPI’s portion-speciﬁc energized natural circulation washing method was reﬂected in the Instructions for energized natural circulation washingof Electrical Devices Contaminated with Trace PCB (amended March 2017) published by the Ministry of the Environment and Ministry of
Economy, Trade and Industry. Moreover, the method for collection of residual oil after heated forced circulation washing was reﬂected in the
Guidelines for Treatment of Decommissioned Electrical Devices Contaminated with Trace PCB ―Washing Treatment Edition― (amended
September 2016) published by the Ministry of the Environment and is utilized for detoxiﬁcation treatment.

After washing, the surface of transformers are covered in washing oil containing PCB and this washing oil thentravels to the bottom of the transformer as residual oil. CRIEPI has devised and veriﬁed a counteracting technologythat urges PCB to shift from the washing oil adhered to the surface of transformer parts to the residual oil throughReference： CRIEPI TOPICS Vol.19 (2015)

depressurization of the transformer, etc. and this has helped to speed up residual oil treatment.

44

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FY2016 Annual Report

45

Electric Power Transmission and Distribution

Energized natural circulation washing methods to date dealt with the entire transformer on the whole, and there

Electric Power Transmission and Distribution

Major Research Results

Background

2–2.

2–2.

Major Research Results-16

Major Research Results–16

Establishing a Power Line-Tree Distance Evaluation
Method Utilizing Drones
Contributing to simple, low-cost maintenance management of power

Electric Power
Transmission andDistribution

transmission equipment

Background
In order to achieve stable power supply, it is essential that regular checks are made of the distance between
overhead power lines and surrounding trees and tree-felling is carried out where necessary. Distance evaluation had
been performed using laser measurement, etc. from aircraft however this is costly and requires special equipment,
therefore it takes time to provide data from measurements. As such, there is a demand for technology enabling thisdistance evaluation for power transmission equipment to be carried out inexpensively and swiftly in regions hard toaccess by humans, such as mountainous regions, and during emergencies. In recent years, there has been a strong（Structure from Motion）

laser measurement from aerial photographs using small unmanned aerial vehicles (drones). CRIEPI is developing
technology to easily and inexpensively perform maintenance and management of power transmission equipment byapplying this SfM mapping to distance assessment for power lines and near-by trees - an application of thistechnology for which there is few precedents.

Outline of Results

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

A technology that ﬁnds an
identical subject (point
correspondences) in
multiple still images
captured so that been
partly overlapped, thenestimating the c a m e r a
capturing position andtarget shape.

focus on a technology called SfM mapping, which creates 3D shape images the same as that obtainable throughMajor Research Results

Major Research Results

SfM◇ Reconstructing 3D shapes from drone photography
As a result of carrying out SfM mapping from a series of photographs captured by a drone hovering directly over thelocations captured, we clariﬁed that 3D shapes could be reconstructed for the power lines and the surrounding tree
canopy by overlapping 80% or more of the visual ﬁeld between images.

Ko Nakaya

Biological Environment Sector,◇ Accuracy of distance evaluation using this technique

Environmental Science Research Laboratory

By comparing the measurement values of power line heights obtained with the existing ground laser range ﬁnder
and values analyzed with SfM mapping, we observed that the measurement error ranged between 0.14 and 0.36 m,
which is equivalent to the measurement error of 0.20 to 0.30 m obtained using high-accuracy laser measurement

Developing a technology for the maintenance and management of power transmission equipment utilizing drones.

from aircraft. This result reveals the potential for drones to enable simple and low-cost evaluation of the distance
between power lines and surrounding trees. Moving forward, we will expand utilization of drones to prediction oftree growth, etc. with the aim of establishing a technique to easily identify appropriate tree-felling timing and

1

2

3

4

location.

Power line
100

Altitude［m］

90

Aerial photos captured by a drone80

The 3D shape image on the left page
was reconstructed from these photos.
Captured July 2015 at Tohoku ElectricPower’s Training Center.

70
60
50

Distance

Height fromground40
30

Tree canopy

0

10

20

30

Distance from baseline［m］

Application Examples of Research Results
Some electric power companies have begun using this technique to evaluate the distance between overhead power transmission equipment andsurrounding trees. Through application in hard-to-access areas, such as mountainous regions, this technology is anticipated to contribute to theeﬃcient maintenance and management of power transmission equipment.

An example of utilizing drones in power line-tree distance evaluation(Left) A 3D shape image produced from aerial photos captured by a drone (right page) and a cross-sectional
diagram circled in red. This shows the distance between the tree canopy and the power lines isapproximately 20 meters.

46

Central Research Institute of Electric Power Industry

FY2016 Annual Report

References: Nakaya et al., CRIEPI Report V15004 (2016)

Central Research Institute of Electric Power Industry

FY2016 Annual Report

47

2-2.

2-2.

Major Research Results -17

Major Research Results -17

Proposal of Rational Countermeasures against Snow
Damage to Power Transmission Facilities
Contributing to the stable supply of electrical power by reducing damage andElectric Power
Transmission andDistribution

halt of facilities due to snow

Background

Outline of Results◇ Establishment of a practical technique for snow damage prediction
Heavy snow accretion
A phenomenon whereby
excessive snow that
accumulates around a
power conductor in acylindrical form leads to
disruption and damage tosupport structures. In someinstances ground faults
occur due to conductors
drooping under the weightof snow accretion, whilein other instances the
conductor short-circuits
due to jumping upwards
as a result of the snow
accretion suddenly
coming oﬀ.

CRIEPI has established techniques to easily predict locations susceptible to damage to power transmission facilities
from the three major causes of snow damage (heavy snow accretion, galloping, salt snow damage), taking into
account the weather patterns of each region. In concrete terms, we have established a technique to estimate themaximum snow accretion on power conductors that should be assumed in snow-resistant design of support
structures such as steel pylons, a technique to identify a span at which short-circuits would easily occur due togalloping based on speciﬁc features of facilities and weather conditions, as well as a technique to identify regions
where there is a concern of salt snow damage to insulators.

◇ Proposing a selection method for appropriate snow-damage countermeasure devices
CRIEPI has analyzed data from long-term ﬁeld observation and various laboratory tests, veriﬁed the eﬀectiveness ofsnow-damage countermeasure devices and clariﬁed the conditions for eﬀects to occur most easily. We haveconducted an analysis of past snow damage events and proposed an eﬀective method for selecting countermeasuredevices to suit the weather conditions of each region and speciﬁc features of power transmission facilities.

Judgment: 1：Necessity of countermeasures toprevent snow accretion

Galloping
A phenomenon whereby aconductor with snow
accretion is subjected towind and oscillates
signiﬁcantly in a verticaldirection. If the amplitude
is too large, it could lead tothe occurrence ofshort-circuits.

Calm ‒ weak windWet/dry

Judgment: 2：Determination of snow accretion type

Unnecessary

Unnecessary

Necessary

Moderate wind ‒ strong wind
Wet

Judgment 4: Necessity of countermeasures forheavy snow accretion (sliding suppression)

Judgment: 3: Necessity of sleet jump measures

Necessary

Salt snow damage

Install counterweights

Unnecessary

Install interphase spacers

Interphase spacer

These prevent
power conductors
from getting too
close to each otherdue to galloping
and also suppress
power conductor
twisting.

Full-scale Test Facilities for Snow damage toOverhead Transmission Lines, commonly known as“Kushiro Test line”

Necessary*1: Can be substituted
Install snow-accretion-resistant rings*1
with a spiral rod

Possibly install snow-accretion-resistant rings*1

Counterweight

Judgment 6: Necessity ofcountermeasures for galloping

Unnecessary
Judgment 7: Necessity of countermeasuresfor power cable shaking

Necessary

Unnecessary

Necessary

An eccentric weightmakes it diﬃcult for the
power conductor totwist, thus preventing
excessive cylindricalsnow accretion inaccompany withpower conductor
twists.

End

Snow-resistance ring

Plastic rings preventing
accumulated snow
from sliding along thetwists in a power
conductor’s surface,
thus preventing
excessive cylindricalsnow accretion.

Example of a ﬂowchart for selecting eﬀective countermeasure devices against snow damage for single
conductor lines and types of countermeasure devices

48

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Aerodynamic force loading test facility
In a wind tunnel capable of generating winds up to 17 m/s, a mock snow-accretion power conductor is set up in the wide space
downstream of the wind supply outlet, enabling experiments which reproduce the galloping of actual power transmission cables orexperiments to evaluate the aerodynamic force acting on snow-accretion power conductors.

Unnecessary

Necessary

Judgment 5：Necessity of countermeasures forheavy snow accretion (twisting suppression)

A phenomenon whereby
wet snow including salt
packs closely ontoinsulators causing them todrastically lose insulation
performance, which could
lead to the occurrence ofelectrical breakdown. Thisis an extremely rare
phenomenon but was oneof the causes of snow
damage in regions on theSea‒of-Japan side in
December 2005.

Takashi Nishihara

Fluid Science Sector, Civil Engineering Research Laboratory

A test line constructed in Kushiro, Hokkaido in FY2013 for the
purpose of conducting tests, observations and analysis aimed
at elucidation of the mechanism of phenomena related tosnow damage, veriﬁcation of countermeasure device
eﬀectiveness and improvement of prediction technology.

Application Examples of Research Results
Parts of the above-mentioned research results have already been utilized by power companies to investigate the cause of snow damage and toformulate preventive measures. Furthermore, applying the results of this research to maintenance, operation and snow-damage countermeasuresfor power transmission facilities allows us to reduce equipment damage and supply hindrance, and to swiftly recover from malfunction even if asnow damage event does occur.

References： Shimuzu et al., CRIEPI Report N16010 (2016)
Honma et al., CRIEPI Report H16004 (2016)
CRIEPI TOPICS Vol. 5 (2011)

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FY2016 Annual Report

49

Electric Power Transmission and Distribution

Electric Power Transmission and Distribution

Major Research Results

Major Research Results

In December 2005, regions on the Sea-of-Japan side were ravaged by severe snowstorms, leading to massive power
outages due to snow damage. In response, the Snow Damage Working Group of the Agency for Natural Resources
and Energy requested that electric power companies should conduct centralized ﬁeld observation and data
management of snow damage events, for which there are rare opportunities to observe, in order to further improveresearch and analysis technology relating to snow damage events. With the cooperation of electric powercompanies in Japan, CRIEPI has completed a 10-year project launched in 2007 in order to elucidate mechanisms
behind snow damage and improve prediction and countermeasure technology.

2–2.

2–2.

Major Research Results-18

Major Research Results–18

Development of a Heat Exchanger with Minimal Frost
Accumulation as a part of Achieving Higher Eﬃciency Heat Pumps
Contributing to energy-saving and comfortable living through high-eﬃciency
dehumidiﬁcation

Background

Heat exchanger

When heating or supplying hot water using a heat pump or freezing/refrigerating with a freezer, if the surface

A device used to transfer
heat from hot substances
to cold substances. In thecase of cooling, a heatexchanger inside theindoor unit transfers theheat in a room to arefrigerant, then the heatexchanger inside theoutdoor unit releases theh ea t o f t h e re f ri ge ra n t
outside.

temperature of the heat exchanger drops below 0℃, the moisture in the air will condense and freeze, causing frost
build up. If a heat exchanger becomes frosted, not only does it lead to decreased heating or cooling performance, italso increases power consumption due to the additional power needed to melt the frost (defrosting). Furthermore,other issues may occur, such as heating or hot water supply being temporarily suspended while the device isdefrosting. As part of eﬀorts to increase the eﬃciency of heating and cooling equipment, CRIEPI is developing aheat exchanger on which frost does not easily accumulate.
Major Research Results

Major Research Results

Customers
Services

Outline of Results◇ Development of a frost-free heat pump water heater and freezer

COP(Coeﬃcient of
Performance)
An indication of the power
consumption efficiency forcooling equipment, etc.,
expressed as a ratio of
cooling performanceagainst power consumption
required for cooling.

solved the issue of frost building up on heat pumps through removing moisture from the air at the heat exchanger
inlet in advance (Fig. 1). As a result of conducting tests and trial calculations under various conditions, it wasapparent that adoption of the DCHE held the potential to improve eﬃciency anywhere from 10 to 30% compared tothe conventional heat pump water heater system. Furthermore, if DCHE is applied to refrigerators or freezers, a trial
calculation of power consumption for an open showcase used in supermarkets, as one example, revealed that COP
could be improved by around 40% compared to the conventional approach (Fig. 2).

Removemoisture
Dry air

frost-free

4
3.26

H 2O

H 2O

H 2O
H 2O

H 2O

H 2O

3

H 2O
H 2O

H 2O
H 2O

H 2O

Fin

H 2O

Heatingtube

H 2O

Low-temperature refrigerant

desiccant[Silica gel, zeolite, etc.]

Fig. 1

An air conditioning systemwith a function to regulate
humidity (humidiﬁcation /dehumidiﬁcation) separate
to regulation of air
temperature. Air
conditioning equipment
without a desiccantfunction consumes energy
unnecessarily due toperforming dehumidiﬁcationby cooling air excessively
then reheating it
afterwards.

50

Heat exchanger (evaporator)

Frost-free concept

COP（-）H 2O

Li Zhang

Consumer Service Unit, Energy Innovation Center

Moist air

Desiccant air
conditioning

Customers Services

Customers Services

CRIEPI has developed a heat exchanger coated with desiccant, the Desiccant-Coated Heat Exchanger (DCHE), and2.27

Heat exchanger test facility
A test facility that measures the heat and mass transfer characteristics of heat exchangers for heat pump applications.

％
43

2
1
0

Conventional
showcase

Frost-free
showcase

Fig. 2 Open showcase COP
trial calculation results

Frost does not build up on the heat exchanger because the desiccant has the eﬀect of removing the
moisture from the air, so that it is dry by the time it reaches the heat exchanger. If used on
freezer-type/refrigerator-type open showcases, it would result in energy-savings as electricity would nolonger be needed to remove frost with an electric heater.

◇ Investigation into desiccant air-conditioning
Desiccant air-conditioning regulates temperature and humidity separately and has attracted attention for some time
now as a form of air-conditioning achieving both comfort and energy-saving. However, the popularization ofdesiccant air-conditioning has been hampered by issues such as large size and high cost. CRIEPI has conducted an

A heat exchanger for frost-freeheat pumps
A heat exchanger coated withdesiccant (the white portion of theﬁgure to the right) in order todehumidify the air at the inlet of theheat exchanger.

Application Examples of Research Results
A frost-free heat pump can contribute to higher eﬃciency of hot water systems in winter, particularly in with regards to hot water heat pumpusage in cold regions. A frost-free freezer would help solve various issues such as deterioration of food quality due to frosting, a drop in eﬃciency
due to a defrosting heater, and disposal of water created in the process of defrosting. It is anticipated that the development of desiccant air
conditioning using DCHE will lead to realization of air conditioning systems which are compact and oﬀer comfort and energy-saving.

investigation into desiccant air-conditioning related products in Japan and ascertained the R&D status. We realizedthat by using DCHE in desiccant air-conditioning, higher eﬃciency and smaller installation space could be achieved
not only for air-conditioners, but also ventilation with outside air and dehumidiﬁcation equipment such as that usedin food manufacturing plants and school lunch supply centers.

Central Research Institute of Electric Power Industry

FY2016 Annual Report

References： Li Zhang, et.al., International Journal of Refrigeration, Vol. 35, pp. 1327-1334 (2012)
Li Zhang, et.al., International Journal of Refrigeration, Vol. 74, pp. 93-102 (2017)

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2–2.

2–2.

Major Research Results-19

Major Research Results–19

Investigation and Analysis of Carbon Pricing Policy
Implemented in the U.S. and Europe
Supporting policy-making through analysis of Carbon Pricing Policy in the U.S.

Environment

An agreement adopted in
December 2015 at the
21st Conference of theParties of the United
Nations Climate Change
Conference (COP21). It
sets out internationalframeworks from the year
2020.

Background
Japan’s global warming measures are entering a new phase amidst the adoption of the Paris Agreement by theinternational community and, within Japan, the establishment of the Electric Power Council for a Low Carbon
Society (ELCS) and the Japanese government’s announcement of the Global Warming Countermeasures Action
Plan, etc. In order to achieve long-term, large-scale reduction of CO 2 emissions, there are ongoing studies into
“carbon pricing”(emissions trading, heavy carbon tax) and it has been pointed out that this policy entails many
issues. Moreover, in FY2016, there was an increase in“tax for global warming countermeasures”and thegovernment is being expected to eﬃciently utilize tax revenue. CRIEPI conducts investigations and analyses relating
to carbon pricing and will continue to investigate potential future policies.

Major Research Results

Major Research Results

Paris Agreementand European countries and eﬃcient usage of Japan’s tax revenue

Outline of Results◇ Investigation and analysis of carbon pricing
CRIEPI has conducted a comparative study into examples of emissions trading schemes adopted in various overseas
countries and Tokyo, and extracted issues of debate surrounding scheme design and market transactions. As a result

Environment

Environmentof this study, we observed that, for all schemes, the emissions quota price was low, therefore the schemes are notfunctioning as a price signal to urge low-carbon investment (Table 1). Furthermore, in addition to the approach of
explicitly pricing carbon emission in ways such as carbon tax and emissions trading, there is also the approach of“implicitly”pricing carbon through regulation and various energy taxes, etc. so that carbon price may be comparedon a global scale. As such, CRIEPI has reviewed overseas literature to better understand the points of debate
surrounding the deﬁnition of“implicit carbon price”, as well as the various evaluation methods for each policy
based on implicit carbon price and limitations of such evaluations. After this review, we raised the point that using aseparate indicator such as energy retail price together with implicit carbon price would be desirable.

Masayo Wakabayashi

Utilities Policy and Economic Analysis Sector,
Socio-economic Research Center

Takahiro Ueno

Energy System Analysis Sector,

Socio-economic Research Center

Proposing future government policies including carbon pricing policy as part of eﬀorts to reduce CO2 emissions.

Table 1 Case study of emissions trading schemes
EU ETS(European Union
Emission Trading
Scheme)An emissions trading
scheme for CO 2 within
the EU.

C&T(Cap and Trade)One form of CO2 emissions
trading, involving setting an
upper limit (cap) on
emission amount thenacknowledging the buying
and selling of emissions
surplus or shortage
between businesses
allocated with emission
quotas.

RGGI(Regional Greenhouse
Gas Initiative)
A regional emissions trading
program participated in bynine states in the U.S.’snorth-eastern region.

52

Scheme name/Applicable region

Current status of scheme operation and issues

EU ETS

Despite of postponing excess emission quotas in 2014-16 andintroduction of strategic Market Stability Reserve (MSR), etc. price issluggish (around €5 to 6/t-CO2) due to surplus emissions quota.

Californian C&T(California, U.S.A.)

Through promotion of energy-saving and renewable energy, as well as
policy for low-carbon vehicle transportation, has achieved a reductionin emissions with the auction price for emission quotas shifting to thelower range ($12.73/t-CO2 in 2016)

RGGI(U.S.’s north-eastern region)

There has been a surplus emissions quota since a drop in demand
after the ﬁnancial crisis, with emissions fetching low prices in auctions
until 2012. The price has been around $5 to 7/t-CO 2 since the cap
was reviewed in 2014.

Total reduction obligation andemissions trading scheme(Tokyo)Many companies have proactively focused eﬀorts on energy-saving toachieve well over targets, creating surplus credit in the market overall
and lowering the credit price to between 1,000 and 2,000 yen/t-CO2.

◇ Evaluation of government projects for global warming/energy-saving subsidization

An award of excellence was received for thisresearch in the“Essay Competition Utilizing the
Database Function of the Government Project Review
Sheet”run by the Administrative Reform Promotion
Council of the Prime Minister of Japan and His
Cabinet, which was oﬃcially awarded by the Minister
for Administration Reforms on September 26th.
Osamu Kimura
Energy System Analysis Sector, Socio-economic
Research Center(http://www.cas.go.jp/jp/seisaku/gyoukaku/H27_review/hyosyo/hyosyo.html)

Application Examples of Research Results
In order to reduce CO 2 emissions in the future to achieve both economic growth and energy security, we will propose desirable government
policies including, but not limited to, carbon pricing policy.

Based on information featured in the Government Project Review Sheet, etc., CRIEPI analyzed the cost eﬀectivenessof each government project to counteract global warming and revealed that the majority of projects were noteﬀective in reducing CO2 emissions. We also demonstrated that there were many ineﬃcient projects whereby the
CO 2 emission reduction unit price was as much as several 100,000 yen per ton, and pointed out that thisineﬃciency needed to be corrected.

Central Research Institute of Electric Power Industry

FY2016 Annual Report

References： Kimura et al., CRIEPI Report Y16002 (2017)
Wakabayashi et al., CRIEPI Report Y16001 (2017)

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53

2–2.

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Major Research Results -20

Major Research Results -20

Detailed Analysis of the Five New Markets in
Accordance with Electricity Market Reform
quantitative market analysis and investigation/analysis of overseas case studies

Capacity market

There is action being taken toward detailed system design and revision regarding the various new markets that will

BackgroundA market that does nottrade supply volume(kilowatts per hour: kWh),but rather future supply
capability (kilowatts: kW).
Two types of capacity
market exist; thecentralized type whereby
a market operator
secures capacity, and thedecentralized type,whereby electricity
retailers secure capacity.

be newly introduced with the Electricity Market Reform (Mandatory Auction for Base load Power, capacity market,

Adequacy

CRIEPI conducted a quantitative analysis regarding the installed capacity of power source required to secure the

The capacity to supply power
demanded by consumers
considering unplanned
outage of power
generation/distribut
i o n equipment andoperational limitations.

supply capability (adequacy) necessary for stable supply assuming the high-volume introduction of renewablebalancing control power market, cross-regional interconnection lines usage rules, non-fossil value trading market).
CRIEPI is helping with the detailed market design reﬂecting the situation speciﬁc to Japan through quantitative
analysis using market models and the appropriate presentation of results obtained through evaluation andtheoretical analysis of case studies in overseas countries pioneering this area.

Outline of Results◇ Quantitative analysis using the wholesaler market modelenergy by the year 2030, as raised in the Long-term Energy Supply and Demand Outlook. Through this analysis, we
discovered that power source able to cover annual expenditure through income from electric power sales in thewholesale market was only around 40% (Fig. 1). We demonstrated that, in order to achieve both the Long-term
Energy Supply and Demand Outlook and stable supply, the creation of a capacity market, etc. as a measure to

Utility Management

secure the necessary supply capability was desirable.
Cash ﬂow per kW [ten thousands yen/kW]

Utility Management

Utility
Management

Major Research Results

Major Research Results

Helping to enhance policy recommendations and mitigate risk through2Long-term
FixedPower source

10Coal (new)
LNGCC
（new）
Petroleum

Kenji Okada / Yu Nagai / Ken Furusawa

Energy Systems Analysis Sector, Socio-economic Research Center

Power sources with the concern ofmarket withdrawal/non-participation

We have proposed a rational system design for the 5 new markets created in accordance with Electricity Market Reform.

Market-adaptive
power sources

-1
-2
-3

Coal
LNGCC
LNG

Adequacy kW price = 18,954 yen/kW

0

6000

12000

18000

Installed capacity [ten thousands kW]

Fig. 1 Cash ﬂow analysis for thermal power source◇ Analysis of detailed system design for new markets

Power Economy Research, Volume 64 (March 2017)“Consistency of the Electricity System Reform andRenewable Energy Policy”
http://criepi.denken.or.jp/jp/serc/periodicals/index.html

CRIEPI investigated and analyzed the detailed design by overseas countries for new markets in accordance with
Electricity Market Reform (Table 1) and proposed a rational approach to system design.

Table 1 Investigation of overseas case studies relating to new market design
New market

54

Case studies, issue of debate, etc.

Mandatory Auction for Baseload Power

Obligatory bidding amount and price setting, France’s wholesale power
regulations targeting nuclear power(Centralized) capacity market

Need to diﬀerentiate between new and existing generation source, handlingof own company’s power source and bilateral contracts

Balancing control power market

Europe’s Cross Border Electricity Balancing mechanism, relationship withcongestion management

Cross-regional interconnectionlines usage rules

U.S.’s PJM locational locational marginal pricing, Financial Transmission
Rights mechanism

Non-fossil value trading market

Demand for non-fossil certiﬁcation, Europe’s Guarantee of Origin (GO),U.S.’s Zero Emission Credits (ZEC)

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Application Examples of Research Results
CRIEPI published the results of a quantitative analysis for supply adequacy evaluation in general newspapers and industrial journals in order tostress the need for a capacity market to the public at large. In regards to the consistency of the Electricity Market Reform and Renewable Energy
Policy, we published our views in Power Economy Research, Volume 64, an academic journal published by the Socio-economic Research Center,and publically raised issues relating to the design of systems for the capacity market, Mandatory Auction for Base load Power, capacity market,
non-fossil fuel value trading market, Balancing control power market, etc., therefore, we anticipate that our research results will be utilized toenhance policy recommendations and mitigate risk.
References: Asano et al., Power Economy Research No.64 (2017)

Central Research Institute of Electric Power Industry

FY2016 Annual Report

55

2–2.

2–2.

Major Research Results–21

Major Research Results–21

Development of an Eﬀective Status Monitoring Technology for Power
Generation Equipment through the Introduction of IoT Technology
Supporting Labor-saving of Maintenance and Management by Achieving

CommonCross-Cutting
Field

Maintenance-free Status Monitoring

BackgroundIn line with aging of electric power infrastructure and equipment, there is a need to establish rational operation andmaintenance technologies. By introducing IoT (Internet of Things), which is attracting attention in recent years, andperforming online detection of device breakdowns in power plants, such as temperature and vibration abnormalities
or diagnosis of deterioration and damage to structural materials used in devices, it is anticipated that the reliabilityof equipment operation could be dramatically improved. CRIEPI is developing technologies in order to utilize energy
harvesters (environment energy harvesters) which self-produce electric power from the heat, vibration and so on in
their installation environment, as power sources for sensors. CRIEPI is simultaneously developing maintenance-free

Major Research Resultsfrom an energy harvester, sensors and a wireless communication device.

Outline of Results◇ Development of vibrational energy harvester using low frequency vibration
Electric double layer
A state whereby opposing
ions become concentrated
in the vicinity of either
electrode when a voltage
is applied to electrolytes.

When electrolytes are held between electrodes and a

Electrode

Electrodesustain in the vicinity of the electrodes. By immobilizing

Electric double
layer electretthese ions while maintaining this electric double layer weElectric double
layer electretElectrodevoltage is applied, an electric double layer is formed tosucceeded in retaining an electric charge semi-permanentlye-Common Cross-Cutting Fielde-

Satoshi Nishinoiri / Hiroyuki Fukutomi

Electrode

Structural Materials Sector, Materials Science Research Laboratory(electret) (Fig. 1). By mechanically modulating contacting
area between electrode and electret we were able toobtain a voltage as high as 2V and with 400μW/cm 2 inDeveloping a maintenance-free status monitoring technology for power generation equipment using an“autonomous sensor network”.

terms of power generation from low frequency vibration
less than 100Hz, which was diﬃcult to generate power

Monitoring thermal power generationequipment status using an autonomous
sensor network

less than 100Hz which is commonly generated from
infrastructure or mechanical systems.
5mmMulti-hop Communication

Fig. 1 The power generation mechanism ofvibration energy harvesters utilizing electric
double layer electrets (top) and the preparedelectric double layer electret (bottom)

A communication method
using nodes in a bucket
relay system to transmit
data.

◇ Building a wireless sensor network for status monitoring of power generation equipment
Rather than an approximate 100-meter Wi-Fi communication distance in an unobstructed communication
environment, by adopting a wireless communication module with a lower frequency than Wi-Fi communication, it ispossible to communicate across a distance of 1 km without multi-hop communication. CRIEPI has built a wirelesssensor network supporting multi-hop communication from a wireless sensor device using this module that also
supports multi-hop communication and a base station to save measurement data to the cloud via a 3G line. We
have seen the potential for this wireless sensor network to be applied to daily maintenance tasks through long-term

It has become possible tocommunicate across a distance of 1
km in unobstructed communication
environments without performing
multi-hop communication, therefore
data can be stored in the cloudwithout omissions even whendriving devices and base stations onsolar power alone.

Environmental Autonomous sensors
heat orvibration
Energy harvesters(Thermoelectric, vibration,
solar power)(Power generation equipment,
combustion equipment, etc.)

we can obtain electric power from environmental vibration

Power supply
Power management circuit(Voltage boost, power
storage, other)
Wireless microcomputer(Signal processing/communication)
Signs ofequipment
abnormalities
Varioussignals

Voltage variation
Sensor element(Temperature, vibration,
distortion, sound)Power supply

using the conventional method. These results suggest that

Thermal power generation equipment

Common Cross-Cutting Field

Major Research Results

status monitoring technology for power generation equipment using an“autonomous sensor network”conﬁgured

Example of sensor implementation

Network
CarrierRelay
gateway

Wireless communication device
56mm

3G lineSpeciﬁed
low-power
wireless(920 MHz)

Cloud

85mm
Signal board
Computer, etc.

Far-infrared Near-infrared
cameracameraPlatinum resistancethermometer sensor

Receivingside Transmitting Temperature andside
Humidity sensor

Analysis engine

Application Examples of Research Results
The application of new vibration energy harvesters capable of power generation at frequencies of 100 Hz or less, which was diﬃcult to do using
the conventional method, there are expectations regarding saving labor and sophistication of daily maintenance tasks. Through demonstration
experiments in thermal power plants, we are verifying the validity of modules adopting a wireless sensor network.

communication tests.

References: Fukutomi et al., CRIEPI Report Q16003 (2016)

56

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Central Research Institute of Electric Power Industry

FY2016 Annual Report

57

2–2.

2–2.

Major Research Results–22

Major Research Results–22

Development of a Technology to Determine OF Cable
Abnormalities by Applying AI Technology
Helping improve the accuracy of cable abnormality determination

CommonCross-Cutting
Field
OF cableAn electric power cablefor high-voltage andultra-high-voltage that has
increased insulation
performance due to being
ﬁlled with insulating oil.

Background
CRIEPI is advancing application of AI techniques in the electric power ﬁeld and has developed a technology that
contributes to the sophistication of work tasks while alleviating the workload of ﬁeld operators through veriﬁcationof a method which is simple, but at the same time capable of sophisticated pattern recognition. One successful
example of AI ﬁeld application is determination of OF (oil ﬁlled) cable abnormalities. OF cable began being laidaround the start of the Showa period (1926), primarily as underground power transmission lines and some on-siteconnecting line. Currently there is a shift towards CV cable, which is easier to maintain, however some OF cables
are deteriorating due to age, therefore accurate detection of abnormalities is important to achieving the appropriate

Major Research Results

Major Research Results

maintenance of OF cable. As part of eﬀorts to detect OF cable abnormalities with higher accuracy, CRIEPI has
developed a technology to determine abnormalities by applying an AI technique.

Outline of Results◇ Proposal of new abnormality determination criteria

Common Cross-Cutting Field

Common Cross-Cutting Field

Individual power companies used to determine abnormality ranking*1 of OF cable intermediate junctions from two
types of data; the amount of acetylene generated due to insulating oil overheating and the total amount of
combustible gas. As an alternative, CRIEPI proposed analyzing the gases included in OF cable oil and establishing

Hiroshi Murata

Yasushi Shinohara / Kazuyuki Masutomi

Energy Innovation Center

Energy Innovation Center

the determination criteria of individual abnormality ranking as well as abnormal portion*2 for the intermediate joints
and terminal joints (Fig. 1) based on the six types of gas included in the oil.

Technology Promotion Unit,*1 Abnormality ranking determination: Rank A (urgent response required), B (Abnormal insulator), C (some form of abnormality
present), D (abnormality-free)*2 Abnormal portion determination: Targets the reinforced insulating paper and cable insulating paper inside the joint◇ Establishment of a determination formula

A typical AI technique tocreate high-accuracy
determination criteria byidentifying/determining
examples (support
vectors) from trained
examples that are close
to the borderline
between normal andabnormal.

Linear support
kernel machine
A technique developed by
CRIEPI to create
determination critiera withhigher accuracy andgreater ease than SVM
utilizing a linear evaluation
formula, by automaticallyreﬁning the variables
eﬀective for determination.

Field application of AI techniques to help mitigate workload and increase eﬃciency regarding management of electric power equipment.

Because people working in the power ﬁeld prefer tasks that can be performed with ease, CRIEPI established a linear
equation using the concentrations of the six gases within oil as the variable as criteria for determining OF cableabnormalities (Fig. 2). In concrete terms, we applied a linear support kernel machine, which is an extended version
doing this, we improved the accuracy rate for unknown data from the approximate 50% capable with theconventional technique to around 80%, thus simultaneously establishing a simple determination formula andOil passage forinsulation

improving determination accuracy.

Terminal
joint

Reinforced insulating
paper
Cable insulating
paper

Example of criteria
for rank
categorization
Terminal (linear equation)
joint

Rank B

Rank C

Cable
Intermediate joint

A conductor with
an electric charge

Rank C
Gas 2

Example of intermediate Example of terminal
joint structure
joint structureIntermediate joint

Rank A

Photo of an OF cable cross-section

SleeveFig. 1 OF cable equipment

Rank D
asG

1

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Application Examples of Research Results
We published the developed criteria for determining OF cable abnormalities in Appendix 9, Issue 1, Electric Technology Research - Volume 70,
which is used by power companies in the maintenance and management of OF cables. Moreover, tools to simplify abnormality determination arebeing used by the individual power companies.

Fig. 2 Concept of the abnormality determination formula

By utilizing data relating to the six gas types, it has become possible to express data collection forabnormality rank and abnormal portion of the intermediate joint and terminal joint in terms of high-order
spatial data. Moreover, by applying the linear support kernel machine and ﬁnding the parameter of thelinear formula that classiﬁes each collection (inclination), categorization can be performed easily even if
the positional relationship between each collection is complex.

58

Paper soaked in oil toachieve an insulating aﬀectof the support vector machine typical of AI techniques, and determined the parameters of the linear equation. By

Gas 3

Support Vector
Machine (SVM)

Digital Transformation Unit,

References： Tsutsumi et al., CRIEPI TOPICS Vol.22 (2016)
Shinohara et al., CRIEPI Report R13002 (2013)

Central Research Institute of Electric Power Industry

FY2016 Annual Report59

Ⅱ．Financial Statement
1.

1.

Overview of Financial Statement

Overview of Financial Statement

Ordinary proﬁt was higher than previous ﬁnancial year, however the increases in the ordinary expenses of both general running costs and laborcosts were suppressed, therefore the current change in ordinary proﬁt was a positive value.

Net Assets Variation Statement（Unit: 100 mill yen）

（100 mill yen）

Ordinary expenses
Labor costs
General running costs

FY2016FY2015

Diﬀerence

298.0

283.0

15.0

97.3

94.6

2.6

200.6

188.3

12.3

Current ordinary proﬁt

11.5

△ 6.7

18.3

Current general net
assets change

28.4

△ 5.6

34.0

FY2016FY2015

Diﬀerence

309.5

276.2

33.3

252.4

235.6

16.8

54.1

37.3

16.7

Other revenue

1.0

1.2

△ 0.1

Transfer from designatednet assets

1.8

1.9

△ 0.1

Ordinary revenue
Ordinary beneﬁt received
Operating revenue

FY2015

Diﬀerence

Transfer to general net assets

1.8

1.9

△ 0.1

Current designated net
assets change

△ 1.0

△ 0.9

△ 0.1

Current net assets change

27.3

△ 6.5

33.8

305.6

300

Transition ofordinary
revenue

150
100

Ordinary
beneﬁtsreceived

0350

Current assets

Subsidy etc. received

FY2016FY2015

Diﬀerence

0.7

1.0

△ 0.2

Transition ofordinary
expenses

250
200
150

273.7

272.7

262.7

235.6

235.6

235.6

252.4

2009

2010

2011

2012

2013

2014

2015

2016 （FY）

321.9

315.0

298.9

292.8

286.1

Generalrunning
costs

1.0

202.7

189.8

175.7

182.3

200.4

188.3

200.6

Labor costs 115.5

112.3

109.1

117.1

103.7

100.3

94.6

97.3

2009

2010

2011

2012

2013

2014

2015

30

Current liabilities

FY2016FY2015

Diﬀerence

42.7

42.3

0.3

497.2

472.9

24.3

Fixed liabilities

91.7

94.0

△ 2.3

Total assets

542.7

517.3

25.3

Total liabilities

134.4

136.4

△ 1.9

4.0

5.1

△ 1.0

General net assets

404.2

375.8

28.4

Total net assets

408.2

380.9

27.3

Designated net assets

FY2016 Annual Report2016 （FY）

21.7

11.5

10

1.8

0

△ 4.4

△ 9.4

△ 20
△ 30

2009

600
500

Transition of
overall assets△ 6.7△ 21.3△ 22.4

2013

2014

568.2

558.6

2015

2016 （FY）

517.3

542.7

2010

2011

2012

498.2

495.2

506.4

505.3

368.3

373.5

375.5

368.4

411.1

387.5

380.9

408.2

2009

2010

2011

2012

2013

2014

2015

2016 （FY）（100 mill yen）

Net assets

Central Research Institute of Electric Power Industry

298.0（100 mill yen）

Fixed assets

60

283.0

206.4

0

Liabilities

44.4

300.8

100
50

（Unit: 100 mill yen）

45.4

309.5

308.0

300

Balance SheetDiﬀerence

276.2

200

△ 10

FY2015

264.7

278.4

50

Transition ofordinary proﬁt

FY2016

288.3

250

20

Assets300.8（100 mill yen）

Change in designated net assets
FY2016343.7

350

Change in general net assets

400
300
200

Net assets

1000* 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

FY2016 Annual Report

61

2.

2.

Financial Statement
Statement of Changes in Net Assets
From April 1, 2016 to March 31, 2017

Balance Sheet

As of March 31, 2017

（Unit: 1,000yen）

Account

Current ﬁscal year

ⅠAssets

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

62

Financial Statement

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

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 balance

FY2016 Annual Report

Central Research Institute of Electric Power Industry

FY2016 Annual Report63Facts & Figures

Central Research Institute of Electric Power Industry

FY2016 Annual Report65Research Results / Intellectual Property

Research Reports / Research Papers / Intellectual Property

Research Network

This section introduces key data on CRIEPI’s FY2016 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

436

158

166

498

453
183

19

Environment

17

50

10

281

Customer energy service

27

Fossil fuel power generation

78

271

270

270

259

217

2012

2013

2014

2015

2016（FY）

Academic papers (peer reviewed)（No. of papers） 1,559

Nuclear power
generation

1,176

1,049

1,412

1,339

971

159

Fig. 4 Breakdown of no. of FY2016 papers by subject field
Advanced basic research
Construction and maintenanceof electric power facilities

1,449

Other

94

25

Socioeconomics

37

106

Information andcommunication

1,062

Power distribution

106

Papers presented at academic conferences

1,409

1500

Environment

123

Customer energy service

25

1,092

91

New energy

66

500

0

Socioeconomics

Information and communication

Transition in no. of papers presented

1000

14

18

New energy

256

Advanced basic research

Construction and maintenanceof electric power facilities

Consigned research report

515
429

Fig. 2 Breakdown of no. of FY2016 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.

Power distribution

Fossil fuel power
generation

383

360

350

368

357

2012

2013

2014

2015

2016（FY）

322

Nuclear power
generation

132

Main Partners for Research Cooperation Agreements and Joint Research
Asia

China Electric Power Research Institute (CEPRI)

428

Korea Electrotechnology Research Institute (KERI)
Korea Electric Power Research Institute (KEPRI)

Fig. 5 Breakdown of no. of FY2016 patent applications by subject field

Fig. 6 Breakdown of no. of FY2016 patent registrations by subject field

Advanced basic research

4

Advanced basic research

Environment

Construction and maintenanceof electric power facilities

3

Customer energy service

9

New energy

4

17

9

Fossil fuel power
generation

11

Nuclear power
generation

9

6

17

Power distribution

New energy

13

5

11

Fossil fuel power generation

Fig. 7

13

Transition of patent /software licenses（No. of patent rights/software）

No. of patent licenses

646

600
500
400

571

440

357

66

Atomic Energy Canada Limited (AECL)

Europe

10

30

19

2012

2013

Battelle Memorial Institute (BMI)

Swedish Nuclear Fuel and Waste Management Company (SKB)

National Agency for Radioactive Waste Management (ANDRA）

Institute for Energy Technology (IFE), Norway

Électricité de France (EDF）

L’Institut de Radioprotection et de Sûreté Nucléaire (IRSN), France

Nuclear power generation

United States Nuclear Regulatory Commission (USNRC)

French Atomic Energy Commission (CEA)

Gesellschaft für Nuklear-Service mbH (GNS), Germany

Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS), Germany
Fortum Power and Heat (Finland)

Studsvik Nuclear AB (Sweden)

Studiecentrum voor Kernenergies ‒ Centre d’etude de l’Energie Nucleaire (SCK・CEN)

National Cooperative for the Disposal of Radioactive Waste (NAGRA)
European Atomic Energy Community (EAEC/EURATOM)

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

Australia

Commonwealth Scientiﬁc and Industrial Research Organisation (CSIRO)

Other International Projects
Mont Terri Consortium

Halden Reactor Project

Participation in International Organizations

200
0National Center for Atmospheric Research (NCAR)

312

300
100

United States Department of Energy (DOE)

European Technology Development Ltd. (ETD), UK

No. of software licenses

700

Electric Power Research Institute (EPRI）

Texas Tech University
Customer energy
service

Information andcommunication

Power distribution

North America (including neighboring countries)

University of California, Los Angeles (UCLA), University of California, Santa Barbara (UCSB)

Environment

Construction and maintenanceof electric power facilities

Taiwan Power Company (TPC)

Korea Hydro and Nuclear Power Company Central Research Institute (KHNP-CRI)

Southwest Research Institute (SwRI)

12

2

Korea Atomic Energy Research Institute (KAERI)

52
2014

Union of the Electricity Industry (EURELECTRIC)
21

12

2015

2016（FY）

Central Research Institute of Electric Power Industry

FY2016 Annual Report

Association of the Electricity Supply Industry of East Asia and Western Paciﬁc (AESIEAP)World Nuclear Association (WNA)

International Electric Research Exchange (IERE)Electromagnetic Transients Program-Development Coordination Group (EMTP DCG) Committee

Central Research Institute of Electric Power Industry

FY2016 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

Power generation

Human Factors Research Center

Distribution

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

Environmental Science Research Laboratory★ 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

CommonCivil 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

FY2016 Annual Report

Central Research Institute of Electric Power Industry

FY2016 Annual Report69Keyword Index

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

A
Active faults......................................... 18

Adequacy ............................................. 54
Alteration Belt.......................................

Life table

EU ETS ................................................ 52

Lightning Location System (LLS)

Existing exposure situations...................... 24

9

Arc ..................................................... 42

B

Fracture Belt .........................................

9Bi-directional Non-contact Power Supply ....... 11

Fuel Ratio .............................................

8............................................ 22

C (T) test

Fusing ................................................. 42

Cable Surﬁng Phenomenon
Capacity market....................... 11

Control rod................... 58
7

Lysimeter ............................................. 30

9Cr steelSevere accident ..................................... 16

M

SfM

The Master Curve Method....................... 22

SiC Power Semiconductor ......................... 10

Multi-hop Communication........................ 56

Smart Meter

Gross Bidding ........................................ 12

HHeat exchanger
Heat ﬂux..................................... 50............................................. 16............................. 48........................ 50
I
IAEA (International Atomic Energy Agency) .... 24

Electric double layer............................... 56

Electric Power Supply/demand
Management Technique ........................... 12
Emergency exposure situations.................. 24

Environment Assessment .......................... 12

Central Research Institute of Electric Power Industry

FY2016 Annual Report............................... 26

Synchronous generator ............................ 36

Human Reliability Analysis (HRA) ................. 20E......................................... 11

Non-technical Skills .................................

Gas Turbine Combined Cycle (GTCC) ........... 32

Heavy snow accretion

Dynamic analysis .................................... 32.................................................... 46

Support Vector Machine (SVM) .................. 58.......................................... 16

Desiccant air conditioning................................. 48

New standards ...................................... 18

8

7

D

Salt snow damage

Gas Turbine ..........................................

Good PRA ............................................

............................................. 28

S

Supply/demand simulator ......................... 32................................. 22

Creep failure ......................................... 28.................................................. 52N9................................................... 50

RGGI

Galloping ............................................. 48

Geothermal Reservoir ..............................

Coal Ash Mixed Material ........................... 30

Reactivity initiated accident (RIA) ................ 16

Sub-surface disposal.................................... 54

Charpy impact testR

ICRP (International Commission
on Radiological Protection) ........................ 24

7

O

T

OF cable .............................................. 58

THERP ................................................. 20

Outcrop observation ............................... 18

Transient stability ................................... 36

Overhead Ground Wire/
Optical Ground Wire (OPGW) .................... 42

Trench survey

VP
Paris Agreement.................................... 52

PCB .................................................... 44
Pit disposal.......................................... 26

Planned exposure situations ...................... 24
Platform....................................... 18.............................................. 38

Power distribution automation.................. 38

Power supply-demand balance ................... 36

L

Probabilistic Risk Assessment (PRA) .............

Laser-Induced Breakdown
Spectroscopy (LIBS) ................................. 10

Pulse ................................................... 16
Pulverized Coal-ﬁred Thermal Power Generation ..

6

Void fraction ......................................... 16

W
Water Tree/Bridging............................... 10

Wood Biomass ......................................

8

X
XML

................................................... 38

XMPP .................................................. 38

8

Central Research Institute of Electric Power Industry

FY2016 Annual Report

71

Keyword Index

C&T .................................................... 5270............................................. 34

G

C

COP

.................. 40

Loss-of-Coolant Accidents .........................

F
6................................................. 30

Line laser............................................. 24

Linear support kernel machine

Filter Vent ............................................

Boron

Keyword Index

Environmental safety ............................... 30

Photo by Kira Sugiyama“Industrial research is the cultivation of wisdom,and should therefore contribute to society”
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