Indian Point Groundwater Contamination

The NRC was notified on Feb. 5, 2016, by Entergy of a new on-site tritium leak at the Indian Point nuclear power plant. Entergy, which owns and operates the Buchanan, N.Y., facility became aware of the leakage via samples drawn from existing groundwater monitoring wells. One of the well samples taken around that time detected tritium levels of about 14.8 million picocuries per liter. Preliminary reviews by Entergy indicated the most probable source of the groundwater contamination was a spill during a water-purification operation involving the plant's Refueling Water Storage Tank. The work was terminated on Jan. 31, 2016.

The NRC immediately began reviewing the event, with Resident Inspectors assigned to the plant beginning the agency's assessments and a Region I-based radiation protection specialist traveling to the site on Feb. 11 to lead the inspection effort. Entergy also initiated its own investigation, which the NRC will continue to follow. The sampling of monitoring wells will also continue to ensure the condition has been corrected. The NRC's review of the company's investigation and assessment will be documented in publicly available reports.

No impacts on public health and safety are expected as a result of the leakage. Groundwater at the site is not used for drinking-water purposes. Further, while the water will slowly migrate to the Hudson River over the course of many months, the concentrations of tritium will be extremely low after entering the waterway because of the significant dilution that will occur. In addition, river water downstream of the plant is brackish and is not used for drinking.

Related documents and activites (including correspondence):
Event Notification submitted on Feb. 10, 2016, regarding leakage
FAQs about Indian Point Groundwater Leakage
Correspondence related to Indian Point Groundwater Contamination
NRC Oversight activities of Indian Point Groundwater Contamination

Background information:
Radioactive effluent and environmental reports for Indian Point 2 and 3
NRC backgrounder on tritium, radiation protection limits and drinking water standards
NRC web page on groundwater contamination (tritium) at nuclear plants
FAQs about liquid radioactive releases

Information on previous leakage issues:
There have been earlier groundwater contamination issues at Indian Point. One of the most notable issues came to light in September 2005 when leakage was identified on an exterior wall of the Unit 2 spent fuel pool. The NRC launched a Special Inspection to review the company's actions in response to the leakage and later put in place a Deviation Memorandum allowing the NRC staff to devote additional resources toward reviewing the company's efforts to identify the source of the leakage, terminate it and develop a network of monitoring wells to measure and track residual groundwater contamination. (The Deviation Memorandum was renewed several times, allowing the additional oversight to remain in place until 2009.)

Entergy developed a comprehensive approach aimed at identifying the scope of groundwater contamination at the site that included the drilling of about 40 monitoring wells. In the course of its evaluations, the company determined that there were two plumes of contaminated groundwater at the site: One resulting from the Unit 2 spent fuel pool leakage and the other from historic leakage coming from the Unit 1 spent fuel pool. The Unit 2 leakage was subsequently determined to be coming from a small weld defect in the spent fuel pool liner that was ultimately repaired. (Unit 1 permanently ceased operations in 1974.) The company subsequently transferred the nuclear fuel from the Unit 1 pool to dry cask storage and drained the pool by the end of 2008, removing it as a source of ongoing groundwater contamination. Under its long-term monitoring plan, the company will continue to sample monitoring well water to check on the status of the contamination. As is the case with more recent leakage, these earlier contamination events do not pose a public health and safety concern, as the contamination is below-ground and groundwater at the site is not used for drinking-water purposes. The abnormal groundwater tritium release into the Hudson River represents a small incremental addition to the normal radionuclides released to the waterway during routine power plant operations. Those releases are well within regulatory limits. The NRC staff inspected the long-term monitoring plan to assess its effectiveness and found it to be satisfactory.