Operators of nuclear powers plants in Japan are investigating whether their plants have potentially faulty quake dampers, after major manufacturers admitted to tampering with product test results, the chairman of the Federation of Electric Power Companies (FEPC), Satoru Katsuno, announced on 19 October. 

Damper maker KYB and its subsidiary have admitted falsifying data and shipping substandard products. Katsuno said the Hamaoka plant in Shizuoka Prefecture uses KYB group dampers, and that its operator is checking whether they are substandard. FEPC is asking other utilities to investigate, after KYB named 70 government and municipal office buildings that may be using substandard earthquake shock absorbers. The company  admitted that products, which failed to meet state standards, had been used at 11 of them. 

The company admitted to cheating on inspection data concerning earthquake shock absorbers for more than a decade. KYB was also found to have been using uncertified materials in the manufacture of earthquake shock absorbers used in a total of 165 buildings.

KYB has 40% of the market for seismic isolator and damping devices in Japan. It said the shock absorber irregularities occurred when materials used for pistons, paint and sealant used in its oil dampers for buildings were changed without obtaining state certification for the alterations. The uncertified dampers were shipped between January 2005 and September 2018. Company sources said work to replace the potentially faulty shock absorbers will probably continue beyond 2020, according to Kyodo news agency.