Issued April 21, 1997

BNL Contact: Mona S. Rowe 516/344-2345
DOE Contact: Jayne Brady 202/586-5806


Horizontal Well Data Now Available

UPTON, NY -- Recent analysis of samples taken from two horizontal wells immediately north and south of the spent fuel pool at the High Flux Beam Reactor (HFBR) at the U.S. Department of Energy's Brookhaven National Laboratory (BNL) did not definitively confirm the pool as the primary source of tritium in the groundwater south of the reactor. Nevertheless, BNL reaffirmed today that analyses of all available data continue to strongly indicate that the spent fuel pool is the predominant cause of tritium contamination.

In March, two horizontal wells, one on the north side and one on the south side of the spent fuel pool, were drilled in the water table, which is about 50 feet below the building foundation, to provide additional data about the source of the tritium plume.

It was expected that the north well upgradient of the groundwater flow and one foot below the water table  would show little or no tritium, while the southern well four feet below the water table would indicate high levels of tritium flowing from the fuel pool.

However, samples from the northern well data show tritium concentrations ranging from 2,000 to 19,000 picocuries per liter; the southern well samples show tritium concentrations of 2,000 to 5,000 picocuries per liter. (See illustration.)


These findings may be the result of differences in the depth that the two wells occupy in the water table. Tritium escaping from the pool may remain in the upper level of the water table, above the depth of the southern well. It is also possible that tritium is seeping from the pool in narrow patterns that bypasses the southern well. The tritium detected by the northern well may reasonably be attributed to leakage from the fuel pool.

Other available data strongly support the spent fuel pool as the primary contamination source:

Small leaks such as those from sewage lines or from pipes embedded in the reactor floor cannot be ruled out as a contributing source but cannot explain the plume.

Next Steps

The laboratory is evaluating alternative sampling methods to confirm the plume source. In addition, the Department of Energy will continue its plan to empty the spent fuel pool, which contains 68,000 gallons of tritiated water at a concentration of 130 million picocuries per liter. DOE and BNL are working with regulators to determine the most effective interim and long-term methods for remediating the contaminated water.

The U.S. Environmental Protection Agency and the Suffolk Country Department of Health Services continue to state that the contamination poses no public health threat.

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