January 21, 2026

Japanese Communist Party Secretariat Head Koike Akira, at a press conference in the Diet building on January 20, said that a company, which played a part in Chubu Electric Power Company’s data fraud regarding earthquake risks at the Hamaoka nuclear power plant (Shizuoka Pref.), has allegedly been involved in preparing seismic data for other nuclear power facilities. He called for the need to check all NPPs for irregularities in their seismic data.

Koike pointed out that Nuclear Regulatory Authority Chair Yamanaka Shinsuke at a press conference on January 14 announced that a company which had received from Chubu Electric a commission to calculate the design basis ground motion for the Hamaoka NPP admitted to its involvement in the data fraud case. Koike said that the NRA chair, however, did not make public the company’s name.

Koike said that the JCP investigated materials attached to Chubu Electric’s application for permission for alterations to the Hamaoka plant, which was submitted for the NRA’s safety screening. He said that the party found that the utility outsourced to three consulting companies the geological survey, the foundation for seismic response analysis, at the Hamaoka NPP. The three companies are: Sogo Geophysical Exploration Co., Ltd, Hanshin Consultants Co., Ltd, and Dia Consultants Co., Ltd.

Koike pointed out that Hanshin Consultants and Dia Consultants under contract with Tokyo Electric Power Company conducted the geological survey at the utility’s Kashiwazaki-Kariwa NPP. This came out in the TEPCO’s application, the same as Chubu Electric’s. This indicates that the three consulting companies have performed geological investigations at various nuclear facilities, said Koike.

He said that it is unacceptable that NRA Chair Yamanaka, despite the revelation of Chubu Electric’s data manipulation, indicated his intent not to reassess other NPP’s seismic data. Koike demanded that the NRA examine the seismic data of all nuclear power plants, including functioning ones.

Past related article:
> Data fraud scandal-hit Chubu Electric Power should give up on restarting Hamaoka NPP [January 16, 2026]