Extensive testing has determined the amount of plutonium that may have washed into Boulder’s wastewater system after a June 9 accident is well below federal and state limits, the National Institute of Standards and Technology said today.
NIST announced June 10 that researchers in a Boulder laboratory discovered that a vial holding about a quarter gram of plutonium-containing powder had cracked and some particles had spilled. In subsequent days, officials said radiation was detected in various parts of NIST’s Building 1 and that two sinks — one in the lab where the incident occurred and one in a nearby men’s restroom — had been contaminated.
A National Nuclear Security Administration team determined that between 76 and 87 percent of the original sample remained in the laboratory room where the spill occurred, primarily at the spill site and with the original glass vial, according to NIST.
“The maximum amount that likely could have been lost when a researcher washed his hands in the laboratory sink immediately after discovering the cracked vial is about 0.06 gram,” said Laura Ost, NIST spokesperson.
Federal and state regulations permit the discharge of 0.0000002 microcuries per milliliter of plutonium into sanitary sewer systems, said NIST.
Calculations by the Department of Energy and NIST indicate that the 0.06 grams of plutonium corresponds to a discharge of about 0.00000014 microcuries per milliliter, which “means that any plutonium washed down the drain would have been below the legal limits,” said Ost.
Airborne contamination was not found in the lab immediately after the accident.
But after a team repeatedly entered the lab, air-sampling equipment placed by the team detected airborne contamination, likely a result of the team’s activities, said Ost. When the team ceased operations, subsequent air sampling showed that radiation readings had returned to normal levels.
Initial examination of laboratory personnel showed they had trace levels of external contamination, NIST said. The health of the lab personnel as well as others who potentially could have been exposed is being monitored.
NIST said it is investigating the incident with the assistance of numerous agencies and that “additional safety and occupational and health experts” are expected to arrive in Boulder today.
“The health and safety of our personnel and local communities is our top priority,” said NIST acting director James Turner. “The fact that this incident occurred is not acceptable. We are actively investigating what happened and have enlisted the help of top radiation safety experts to review our procedures.”
Turner said NIST is committed to strengthening its safety program to help prevent “safety incidents” in the future.
Maureen Rait, Boulder’s director of public works and interim city manager, said Boulder officials have found no adverse effects from the potential plutonium release into the wastewater system.
Rait said that extensive monitoring at the city’s wastewater plant and of Boulder Creek — where discharge of the treated water goes — shows that no employees nor aquatic life have been affected.
“We don’t believe there is any threat to businesses and homes,” said Rait. “There is no reason to be concerned.”
Howard Pankratz: 303-954-1939 or hpankratz@denverpost.com
