The restart of power generation at Japan’s Onagawa Nuclear Power Plant Unit 2, scheduled for November 3, has been postponed due to a malfunction with measurement equipment within the reactor, local media reported, Report informs via Xinhua.

The issue arose when a device designed to improve the precision of neutron data readings stopped working partway through installation, the country’s public broadcaster NHK reported, citing Tohoku Electric Power company.

Onagawa Power Plant Unit 2, located in Miyagi Prefecture, was restarted on Oct. 29 for the first time since being shut down following the 2011 earthquake and tsunami.

Tohoku Electric had planned to resume power generation after a successful reactor restart, but the delay occurred during testing.