Japan NUS Co., Ltd.

Japan NUS Co., Ltd., commonly known by its brand name JANUS, is a Japanese consulting and engineering services company headquartered in Tokyo. It was founded in 1971 with the capital and technology of the U.S. firm NUS Corp. and JGC Corporation, and with equity participation from Tokyo Electric Power Company. The company was established to provide consulting and engineering services related to nuclear power, and it soon expanded into environmental consulting. Over the decades, JANUS broadened its scope from nuclear energy to energy in general, and then to global environmental issues, waste management, and general science and technology system development. JANUS operates as part of the JGC Group, a major Japanese engineering conglomerate. Its services include atmospheric dispersion simulation, marine dispersion simulation, decarbonization consulting, plant operation support (P-SADS), asbestos measurement support (Mecolas®), business formation support and technical review, probabilistic risk assessment (PRA), marine litter countermeasures, PDE/OEL setting for pharmaceutical manufacturing, economic ripple effect evaluation, risk communication, and fisheries compensation. The company serves government agencies, electric utilities, and private enterprises, and it has a strong focus on nuclear safety, risk assessment, and regulatory affairs. The firm has a history of international collaboration, having concluded business cooperation agreements with organizations such as SCIENTECH (USA), ARIA Technologies (France), Virginia Power Nuclear Services (USA), NERA (USA), Value Research Institute (Japan), Tokyo University of Marine Science and Technology's Tokyo Bay Ecosystem Research Center, Tsinghua University (China), SOGREAH (France), and Beijing Zhenyoutang Consultant Co., Ltd. (China). It has also been involved in CDM-related projects in China. In recent years, JANUS has been active in climate change adaptation, nature-positive initiatives, and digitalization. It exhibited at NATURE TECH! in 2026, promoting support for national, regional, and corporate clients in nature positivity, climate change countermeasures, and more. The company also publishes thought leadership content, such as a series of essays with nuclear expert Amir Afzali on the future of nuclear energy in Japan. JANUS continues to provide consulting services to Japanese government ministries and agencies, as evidenced by its recent contract awards for chemical substance impact assessments, hazardous facility accident investigations, nanomaterial surveys, nuclear disaster impact studies, and climate change adaptation planning.

Japan NUS Co., Ltd. was founded in 1971 as a consulting and engineering services company focused on nuclear power. It was established with the capital and technology of NUS Corp. (USA) and JGC Corporation, and with equity participation from Tokyo Electric Power Company. In 1972, the company expanded into environmental consulting and engineering services. In 1974, Kansai Electric Power Company and Chubu Electric Power Company also took equity stakes. In 1977, the company broadened its focus from nuclear power to energy in general. During the 1980s, JANUS expanded into global environmental and waste-related businesses. In 1991, it entered the field of consulting and engineering services for system development in general science, technology, and industry. In 1996, the energy-related division of NUS Corp. was sold to SCIENTECH (USA), and JANUS concluded a business cooperation agreement with SCIENTECH. In 1998, it signed cooperation agreements with ARIA Technologies S.A. (France) and Virginia Power Nuclear Services (USA). In 1999, it signed an agreement with NERA (USA). In the 2000s, JANUS continued to form partnerships: with Value Research Institute, Inc. in 2003; with the Tokyo Bay Ecosystem Research Center of Toho University's Faculty of Science in 2004; with Tsinghua University (China) in 2006 to start CDM-related projects in China; with SOGREAH (France) in 2007; and with Beijing Zhenyoutang Consultant Co., Ltd. (China) in 2012. In recent years, JANUS has focused on climate change adaptation, nature-positive initiatives, and digitalization. It has developed services such as the AI asbestos detection support system Mecolas® and the plant operation support service P-SADS. The company remains active in nuclear safety, risk assessment, and regulatory affairs, and it continues to receive contracts from Japanese government ministries and agencies for a wide range of environmental and nuclear-related studies.

• 2012

  Concluded a business cooperation agreement with Beijing Zhenyoutang Consultant Co., Ltd. (China).

• 2007

  Concluded a business cooperation agreement with SOGREAH (France).

• 2006

  Started China CDM-related projects in collaboration with Tsinghua University.

• 2004

  Concluded a business cooperation agreement with the Tokyo Bay Ecosystem Research Center, Faculty of Science, Toho University.

• 2003

  Concluded a business cooperation agreement with Value Research Institute, Inc.

• 1999

  Concluded a business cooperation agreement with NERA (USA).

• 1998

  Concluded business cooperation agreements with ARIA Technologies S.A. (France) and Virginia Power Nuclear Services (USA).

• 1996

  NUS Corp.'s energy-related division was sold to SCIENTECH (USA); JANUS concluded a business cooperation agreement with SCIENTECH.

• 1991

  Entered consulting and engineering services for system development in general science, technology, and industry.

• 1990

  Expanded global environmental and waste-related businesses.

• 1977

  Expanded from nuclear power to energy in general.

• 1974

  Received equity participation from Kansai Electric Power Company and Chubu Electric Power Company.

• 1972

  Entered environmental consulting and engineering services.

• 1971

  Founded with capital and technology from NUS Corp. (USA) and JGC Corporation, with equity participation from Tokyo Electric Power Company.

A trusted consulting and engineering partner for energy and environmental challenges, leveraging advanced simulation, risk assessment, and digital technologies to support government and industry clients.

• Mecolas®

  AI asbestos detection support system.

• P-SADS

  Plant operation support service.

• Probabilistic Risk Assessment (PRA)

  Risk assessment service for nuclear and other facilities.

• Atmospheric dispersion simulation

  Simulation service for atmospheric dispersion.

• Marine dispersion simulation

  Simulation service for marine dispersion.

• Decarbonization consulting

  Consulting for decarbonization.

1. 1トップページ - エネルギーと環境を考える 日本エヌ・ユー・エス株式会社（JANUS）janus.co.jp
2. 2沿革 - エネルギーと環境を考える 日本エヌ・ユー・エス株式会社（JANUS）janus.co.jp
3. 3会社情報 - エネルギーと環境を考える 日本エヌ・ユー・エス株式会社（JANUS）janus.co.jp
4. 4サービス・ソリューション - エネルギーと環境を考える 日本エヌ・ユー・エス株式会社（JANUS）janus.co.jp
5. 5Japan NUS Co., Ltd. (Japan) - Wikidatawikidata.org