A nuclear reactor at New York’s Indian Point power plant was forced to shut down Monday due to an “electrical disturbance,” days after its operational license expired.

Unit 3 was turned off around 7pm Monday and reportedly posed no threat to staff or the public. The shutdown took place just hours after dozens of anti-nuclear activists held a demonstration on site to protest the continued use of the reactor after its license expired at midnight on December 13.

It is also the latest in a series of unexpected failures at the power plant, which is situated roughly 30 miles north of New York City and operated by New Orleans-based firm Entergy. New York Governor Andrew Cuomo ordered an investigation into the shutdown and said that the “recent unplanned outages” require “increased inspections and scrutiny” at the site.