Vol. 78, No. 3, May 2023

Special Reports

Nuclear Energy Contributing to Carbon Neutrality and Stable Energy Supply

ENDO Noriko

USUI Hidekazu / HAGIWARA Tsuyoshi

Toward the reduction of greenhouse gas emissions by 46% in FY2030 and the achievement of carbon neutrality by 2050, the Japanese government is promoting green transformation (GX) with the objective of reforming the country’s energy supply and demand structure and ensuring stable and economical energy supplies. The effective utilization of nuclear power is an important factor in achieving this objective. In addition, the role of nuclear power has become increasingly significant from the viewpoint of energy security in recent years.

The Toshiba Group is responding to these social requirements by making efforts to contribute to the realization of GX by promoting the development and expansion of a wide variety of businesses related to nuclear power. These include (1) construction of plants and supply of fuel, (2) provision of operation and maintenance services, and (3) development of next-generation innovative reactors and nuclear applications.

NAKAHARA Takayuki / SUGIURA Tessai / NARABE Tohru

Since the reactor cores of the Fukushima Daiichi Nuclear Power Station (hereafter referred to as “1F”) Units 1 to 3 were seriously damaged by the Great East Japan Earthquake and the ensuing tsunami on March 11, 2011, both the public and private sectors have been steadily working to control the aftermath of the accident and ensure the safety of the damaged facilities.

Toshiba Energy Systems & Solutions Corporation has been making significant contributions to these endeavors, including the installation of equipment for removing fuel from the spent fuel pools, investigations of the interiors of the reactor primary containment vessels (PCVs), and installation of facilities for contaminated water treatment. Utilizing our experience and expertise in these areas, we are continuously making efforts to address the decommissioning of 1F and the management of the contaminated and treated water.

IWASAKI Atsushi / HASEGAWA Takeshi / YAMAMOTO Yoshikatsu

With the aim of restarting the Onagawa Nuclear Power Station Unit 2 of Tohoku Electric Power Co., Inc., various types of construction work are in progress to implement multiple safety measures in order to avoid the possibility of a severe accident. These measures, such as seismic reinforcement of the main equipment, installation of new cables and pipes for facilities subject to new regulatory requirements, and so on, are being implemented simultaneously by a number of different contractors working inside the limited space available at the plant.

To prevent delays in the restarting schedule caused by complicated construction processes or the need for reworking, Toshiba Energy Systems & Solutions Corporation, in cooperation with Tohoku Electric Power Co., Inc., has conducted a feasibility study on the construction work and is making efforts to design the layout of the operations and secure the necessary work areas by sharing its plant operation support service tools including the 3D Plant Viewer with other contractors. In addition, we have embarked on collaborative activities with relevant parties to minimize the risk of restarting the plant.

KURODA Masatomo / HIGUMA Koji / HASEGAWA Manabu / KOIWAI Masatoshi

From the viewpoint of placing the highest priority on safe and stable operation and improvement of the capacity factor of restarted nuclear power plants, there is a need for technologies to monitor their operating conditions and to plan and efficiently implement maintenance scenarios.

Toshiba Energy Systems & Solutions Corporation has devised a new scheme called the Operation and Outage Control Center (O&OCC) for installation in nuclear power stations. The O&OCC can provide engineering support services through close collaboration of the electric power company’s plant operation technologies and our field and design technologies. This will make it possible to enhance the effectiveness and efficiency of plant operations through the development of analysis and evaluation tools based on our plant design and support experience and artificial intelligence (AI) technologies. In addition, we are aiming to maximize electric power generation while ensuring plant reliability by applying latest technologies for inspection, maintenance, and renewal work.

MIKI Yusuke / MAEHARA Takahiro / SUZUKI Jun

As an all-round nuclear power plant supplier, Toshiba Energy Systems & Solutions Corporation has designed and constructed many of the major components of the Rokkasho Reprocessing Plant of Japan Nuclear Fuel Ltd., which is the core plant for the establishment of a nuclear fuel cycle in Japan. This work has included the delivery of a wide variety of products, ranging from facilities for low-level waste treatment and storage and the control building though to important equipment for reprocessing such as the settling centrifuge and burn-up monitor.

Toward completion of the plant, we are now engaged in evaluation and modification of these products to enhance safety in accordance with the new regulatory requirements, which were revised based on the lessons learned from the accident at the Fukushima Daiichi Nuclear Power Station.

MATSUMOTO Keiji / YONEDA Tetsuya / AOKI Yasutaka / GOTO Keita

As a result of the accident at the Fukushima Daiichi Nuclear Power Station, which was seriously damaged by the Great East Japan Earthquake of March 11, 2011, many residents of the surrounding area are still forced to live elsewhere as evacuees. Existing nuclear power plants in Japan are now required to implement additional safety measures, including various active safety systems and a specialized safety facility, following the enforcement of new regulatory requirements in response to this situation. Newly constructed nuclear power plants are also required to achieve further improvements in economic efficiency.

Under these circumstances, Toshiba Energy Systems & Solutions Corporation is developing the iBR, an innovative, intelligent and inexpensive boiling water reactor that realizes enhanced safety through in-depth countermeasures to prevent a severe accident in the event of a large-scale natural disaster. The passive safety systems of the iBR can function as a specialized safety facility without any help from outside the station for a period of seven days, so there is no need for emergency evacuation nor for permanent relocation even in a severe accident situation. The iBR is based on the advanced boiling water reactor (ABWR), which has a proven track record, making it easy to construct and to achieve high economic efficiency.

FUJIWARA Seiji / ASANO Kazuhito / TAKAYAMA Tomoh

Attention is being focused on the high-temperature gas-cooled reactor (HTGR), a type of nuclear reactor offering high safety in which core meltdown accidents are avoided by employing ceramic-coated fuels that are resistant to high temperatures. Since heat at temperatures exceeding 700°C extracted from an HTGR can be utilized not only for power generation but also for a variety of applications including hydrogen production and steam supply to industrial plants, the development of HTGRs is being promoted in various countries. In Japan, a demonstration HTGR called the High Temperature Engineering Test Reactor (HTTR) has been successfully operated and the construction of a next-generation HTGR in the 2030s is also being planned.

The Toshiba Group has been engaged in the research and development of HTGRs with the objective of achieving practical implementation at an early stage. In addition to baseload power generation, we are making efforts to realize a hydrogen production system applying a high-temperature steam electrolysis technology as well as to develop a power generation system equipped with a heat storage system in cooperation with Fuji Electric Co., Ltd., aimed at balancing electricity supply and demand in response to the introduction of power generation using renewable energy sources and expanding the utilization of heat generated by HTGRs to the industrial, consumer, and transportation sectors.


As a means of achieving both energy security and carbon neutrality, demand for the construction of nuclear power plants equipped with reactors ranging in size from small to large-scale units continues to grow worldwide.

Toshiba Energy Systems & Solutions Corporation supplies a wide variety of equipment as well as operation and maintenance (O&M) services to customers around the world, including those for pressurized water reactors (PWRs), based on the technologies it has developed in the construction of and provision of O&M services for boiling water reactors (BWRs) in Japan. In particular, for the construction of large PWRs, we have supplied steam turbine generators (STGs) to eight plants whose construction started after the accident at the Fukushima Daiichi Nuclear Power Station. We will continue to provide highly reliable equipment and high-quality O&M services, and will contribute to the realization of global carbon neutrality by utilizing our experience in large reactors and our extensive knowledge and experience in STGs for thermal power generation.

IWAKI Chikako / KUBO Tatsuya / HARUGUCHI Yoshiko

Toshiba Energy Systems & Solutions Corporation is developing innovative nuclear technologies in response to social needs, applying various fundamental technologies accumulated through its decades-long experience in the nuclear field. At the same time, we are also expanding these activities into fields other than nuclear power.

Through the advancements we have made in this development work, we have established the following innovations: (1) the concept of MoveluX™, a unique ultracompact reactor that achieves autonomous reactor shutdown and high safety by employing solid moderators and thermal siphons based on reactor physics and thermal fluid technologies; (2) a technique to improve the corrosion resistance of silicon carbide (SiC) based on materials technology, thereby improving the safety and economic efficiency of light water reactors; (3) an image diagnosis technology for the evaluation of phased array ultrasonic flaw detection data to further improve the safety and economic efficiency of light water reactors; and (4) a method applying radiation measurement technology for the monitoring of fuel debris using cosmic ray muons, which we are planning to apply not only to nuclear power systems but also to the monitoring of infrastructure under construction.

Feature Articles


Heat-pipe type self-cooling silicon rectifiers have been widely used in electric railway systems as key equipment for DC feeding substations. In the renewal of these silicon rectifiers due to aging, it has become increasingly difficult in recent years to ensure adequate space for replacement under congested conditions caused by other equipment installed inside the substation.

To resolve this issue, the Toshiba Group has developed a new compact heat-pipe type self-cooling silicon rectifier featuring small size and light weight for indoor use and installed the first product at the Oyamazaki Substation of Hankyu Corporation. This compact silicon rectifier, which achieves reductions in both volume and mass of about 40% compared with our conventional products, makes it possible not only to implement the renewal of aging rectifiers that have been considered difficult to replace due to the lack of space, but also to secure the space to install other equipment that will be renewed in the future.

TANGO Toshihiro / YOSHINO Tadayuki / CHIKENJI Takamitsu

A recent trend in mobile communication systems has been an acceleration in the transition from current fourth-generation (4G) to fifth-generation (5G) mobile communications, thereby realizing high-speed, large-capacity data transmission.

Toshiba Infrastructure Systems & Solutions Corporation has been developing and supplying a variety of distributed antenna systems (DAS) that make it possible to expand a communication area through the relay transmission of radio waves from the base station. We have now developed a DAS system applicable to both 4G and 5G mobile communications comprising DAS equipment and a DAS management system. The DAS equipment incorporates (1) a hardware platform design for the master unit featuring the use of expansion slots, printed circuit boards divided according to each functional block, and a highly versatile radio frequency (RF) transceiver integrated circuit (IC); and (2) standardization of wireless performance compliant with the Third Generation Partnership Project (3GPP) standards through the use of a newly developed timing detection function for time division duplexing (TDD) signals and optimization of the power amplifier characteristics in the remote units. The DAS management system incorporates open-source software (OSS) in order to achieve a balance between running cost reduction and quality assurance.

ETO Masaya / KUDO Riki / TANAKA Kazuyuki / TAKAHARA Katsuhiko

Skin analysis services for end users in the cosmetics industry have become a focus of attention in recent years. However, the provision of these services requires expensive dedicated equipment and evaluation by an expert, increasing costs.

Toshiba Digital Solutions Corporation, in cooperation with FANCL Corporation, has developed an artificial intelligence (AI) model capable of estimating the shapes of cells and biomarker levels using images of the stratum corneum in order to fully automate the process of skin analysis uniquely developed by FANCL Corporation as a storefront service. We have applied this AI model to skin analysis using the SATLYS Toshiba Analytics AI service and created a new cloud-based service. The new service makes it possible to automatically obtain results in less than a minute, achieving quick and easy operation at low cost.


Cloud services have become widely used in recent years to realize various services using data obtained by Internet of Things (IoT) devices, including sensors and other equipment. Although the providers of cloud computing platforms ensure the quality of the hardware devices used in these platforms, constructors of cloud systems are entirely responsible for the quality of their systems. In particular, ensuring security in the construction of cloud systems and their operations has become an issue of critical importance.

The Toshiba Group has developed and is operating the HABANEROTS IoT platform service, which provides functions for the collection of data from and remote control of large numbers of IoT devices. In order to further enhance the security of HABANEROTS and ensure its continuous operation, we have now developed a security monitoring system, created a management scheme for the system using Infrastructure as Code (IaC) tools, and established a monitoring operation system to respond to any security incidents that may occur.


The Toshiba Group is making efforts to promote servitization due to the transition from conventional manufacturing and sales of products to product-service systems (PSS) capable of making effective use of data from products. It has become important for the acceleration of this transition to acquire new capabilities achieved by complementing the different knowledge and skills accumulated in each department. This makes it essential to allow sharing of information on where knowledge and skills for PSS exist among multiple departments.

For this purpose, Toshiba Corporation has evaluated the existing knowledge and skills of its design departments using its Cyber-Physical Systems x Design Division as an example, and created a capability map to visualize the capabilities necessary for PSS in order to share them with other departments.

Frontiers of Research & Development

Higher Harmonic Resonance Suppression Control Technology for Smooth Introduction of Grid-Connected Converters Applying Adaptive Approach Based on Grid Conditions

*Company, product, and service names appearing in each paper include those that are trademarks or registered trademarks of their respective companies.