Boulder, Colo. – Re-entering the sealed laboratory room where a small plutonium spill occurred on June 9, National Institute of Standards and Technology (NIST) radiation safety experts have found contamination in a laboratory sink and other surfaces within the laboratory. NIST has updated city of Boulder officials and the Nuclear Regulatory Commission (NRC) on the latest findings.
Meanwhile, two regional members of the Department of Energy (DOE) Radiological Assistance Program will be arriving at NIST's invitation later today for a consultation to explore ways in which the DOE can help with assessing the contamination and cleanup. In addition to carrying out its own investigation and cooperating with an NRC investigation, NIST is asking for assistance from outside radiation safety officials to carry out a probe of the incident.
"We have asked for this extra help because we want to be sure that we fully understand how this incident occurred. We want to make sure we clean up the contamination properly and we want to know if there are any improvements we can make in our safety program," said James M. Turner, NIST deputy director.
In the past few days, NIST health physicists have re-entered the lab where the June 9 incident took place for the first time since the room was sealed. They started an inventory of the plutonium contamination in the room. They detected contamination on the floor and on various tabletops and surfaces, consistent with a spread of material by hands and shoes.
They also found contamination in the laboratory sink and subsequently learned that a researcher who worked directly with the plutonium sample had used that sink to wash his hands during the incident. NIST has alerted the city of Boulder and city waste water treatment plant personnel to this new information. The discharge from the sink enters the sanitary sewer system. While the exact amount washed down the drain is not known, the entire amount of plutonium in the sample was approximately 1/4 gram*. NIST is conducting studies to determine a better estimate of the amount of radiation discharged.
The main health risk from plutonium occurs through inhalation or ingestion. NIST continues to monitor the health of its affected laboratory personnel.
NIST remains in close contact with the NRC over the status of the situation in Boulder. The NRC investigation into the incident is also continuing.
NIST will work with independent radiation experts to conduct an investigation into the causes of the June 9 event and evaluate the effectiveness of NIST's actions in responding to the incident. Kenneth C. Rogers, former commissioner of the Nuclear Regulatory Commission from 1987 to 1997, has agreed to assist NIST in this effort.
The experts will make site visits to NIST in both Boulder, Colo., and Gaithersburg, Md. They will conduct interviews and gather facts, receive access to NIST data and information on the incident, and then inform NIST of their findings. The information provided by these experts will be used by NIST to prevent similar incidents in the future.
*Corrected July 17; the sample included 1/4 gram of plutonium in the form of 0.53 gram of plutonium sulfate tetrahydrate.
Additional information on the NIST Boulder plutonium incident is available at http://www.nist.gov/public_affairs/releases/boulder-incident.html.