ALBANY, N.Y. (CBSNewYork/AP) — The operator of the Indian Point nuclear power plant reports that bird poop was the likely cause of a reactor shutdown in December.

Entergy Corp. said an outside expert is analyzing whether what’s technically called bird “streaming” was the culprit when the Indian Point reactor safely shut down following an electrical disturbance on outdoor high voltage transmission lines.

In a report to the Nuclear Regulatory Commission last month, the company says the automatic reactor shutdown Dec. 14 was apparently from bird feces that caused an electric arc between wires on a feeder line at a transmission tower.

The Indian Point Entergy Center told the NRC it was revising preventive maintenance to include inspection and cleaning and installing bird guards on transmission towers.

The outage came just days after control rods lost power at the Indian Point 2 reactor, forcing it to shut down for three days. Following that incident, opponents of the plant said Indian Point should close for good, pointing to a handful of other mishaps last year including a transformer fire and water pump problem.

Last month, Gov. Andrew Cuomo called for an investigation after an apparent overflow at the plant spilled highly radioactive water into an underground monitoring well. Nuclear regulators said the public wasn’t at risk.

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