US Entergy Corp is extending an outage at its Indian Point NPP Indian Point in Buchanan, New York state, after discovering bolts missing in the unit 2 reactor.

US Entergy Corp is extending an outage at its Indian Point NPP Indian Point in Buchanan, New York state, after discovering bolts missing in the unit 2 reactor.

Engineers inspecting the reactor had identified missing bolts and bars designed to hold them in place, along with "other degradation requiring replacement", the New Orleans-based Entergy said in a 29 March statement. Completing the investigation and making the necessary repairs could extend the scheduled maintenance outage, which began on 7 March, by several weeks and would increase costs, it said. Entergy said the problems did not affect public health or safety, and that inspections had shown that "critical components at unit 2 continue to perform safely and as intended".

Entergy said more than 2,000 bolts had been inspected when the reactor was shut down. More than 200 of the bolts needed further analysis and some bolts on the reactor’s inner liner were missing. Each bolt holds plate inserts together inside the nuclear reactor.

The Indian Point facility has a long history of issues and New York Governor Andrew Cuomo was already campaigning for its permanent closure, arguing that evacuating a metropolis such as New York City would be impossible in the event of a major accident at the station. In December, he ordered the state’s utility regulator to look into operations and safety protocols after an unexpected shutdown at the plant.

In February, Entergy said it had detected elevated levels of tritium in groundwater samples at the plant site after an apparent spilled highly radioactive water into an underground monitoring well, but nuclear regulators said there was no risk to the public. The leak occurred after a drain overflowed during a maintenance exercise while workers were transferring contaminated water, said Neil Sheehan, a spokesman for the Nuclear Regulatory Commission (NRC). Normally, a sump pump would take the water and filter it into another treatment system, but the pump apparently was out of service, Sheehan said. After the drain overflowed, the water seeped out of the building into the groundwater.

It was unclear how much water spilled, but samples showed the water had a radioactivity level of more than 8m picocuries per litre, a 65,000% increase from the average at the plant, Cuomo said. The levels are the highest regulators have seen at Indian Point, he added. In a statement, Entergy also said, "While the effect of these elevated values is less than one-tenth of one percent of federal reporting guidelines, Entergy made voluntary notification to the NRC, state agencies and key stakeholders."

However, Indian Point has a history of groundwater contamination. NRC issued a report after about 100,000 gallons of tritium-tainted water entered the groundwater supply in 2009, and elevated levels of tritium also were found in two monitoring wells at the plant in 2014. Officials said then the contamination likely stemmed from an earlier maintenance shutdown. Entergy has since 2007 sought a 20-year renewal of its federal licences for the plant. However, in November, New York state denied a certification for Entergy, claiming Indian Point failed to comply with coastal-management regulations.