Contact: Mona S. Rowe, or Kara Villamil
Upton, NY - The U.S. Department of Energy's Brookhaven National Laboratory reports today on recent corrective actions taken in response to a comprehensive, site-wide facilities review begun in April of this year.
As highlighted in the facilities review interim report issued on September 10, environmental concerns are subdivided into two broad categories: "Underground Sumps, Tanks, Lines and Ducts" and "Historic Discharges of Solvents, Oil, and Mercury."
Air Duct in Graphite Reactor Complex
BNL's Brookhaven Graphite Research Reactor operated from 1950 to 1968. As part of an ongoing investigation of the graphite reactor complex, BNL inspected, on September 15, a below-ground air duct that was used to cool the reactor when it was operating. Subsequently, the Lab determined that the air duct contains approximately 60,000 gallons of water, and initial sampling and analyses indicated that the water is contaminated with the radioactive elements strontium, cesium and tritium.
BNL has now identified additional radioactive elements in the water. The Lab will begin the process of pumping out the water next week and will start groundwater monitoring in the area the following week.
The water level in the duct is approximately 25 feet below ground. Radiation measurements are at normal background levels above ground, at the surface. Neither BNL workers nor members of the public are being exposed to the water. The lowest point of the air duct is about 30 feet above the water table in the area.
BNL has prepared a procedure for pumping water out of the air duct and forwarded the pumping plan to regional environmental regulators for their information. The pumping process is scheduled to begin the week of October 27 and will last several weeks. The water will be temporarily stored in tanks that sit within lined containers to prevent environmental release, and the tanks are located in a paved, curbed and isolated area on the Lab site. BNL will treat the water and/or transport the water off site for disposal.
Past leakage from cooling coils and rainwater intrusion are the likely sources of water in the air duct. The cooling coils are no longer a source of water, and BNL is evaluating methods to prevent rainwater from getting into the duct.
In early November, the Lab will begin additional groundwater monitoring as close to the graphite reactor complex as possible, to check if the duct is leaking. Previous monitoring directly east of the reactor complex and up to 500 feet south showed tritium levels less than 1,000 picocuries per liter (pCi/L) and strontium ranging up to about 50 pCi/L. Samples taken even further south show a drop in strontium levels.
With the exception of tritium, which behaves like water, most radioactive elements tend to bind to soil, greatly retarding their movement in groundwater. For that reason, if the air duct has leaked, contamination is expected to be localized near the graphite reactor.
Listed below are the principal radioactive elements identified in three unfiltered water samples from the underground air duct. The samples show a ranges of values. Reported are the peak concentrations.
|Radioactive Elements||Peak Concentration|
|strontium-90||10 million pCi/L|
|cesium-137||4 million pCi/L|
|tritium||50 thousand pCi/L|
Brookhaven's graphite reactor split uranium atoms to produce neutrons for research. That process, called nuclear fission, produces the elements strontium and cesium. If a uranium atom absorbs a neutron but does not split, it can turn into plutonium, which decays into americium. Tritium is created when hydrogen, which is in water, absorbs neutrons.
Plutonium, a toxic metallic element, emits a type of radiation that is easily stopped by paper or skin or even a few inches of air; it is a hazard only when ingested or inhaled. The plutonium concentrations listed above correspond to a trace amount of solid material, or less than 0.00003 ounce distributed in the 60,000 gallons of water contained in the air duct.
In addition to the planned removal of the contaminated water from the duct and groundwater monitoring, BNL has set up a team to address the environmental issues associated with the graphite reactor complex. The Lab and DOE are working together to increase monitoring and stabilization activities.
Other Completed Actions
In other actions taken this month in response to the findings of BNL's facilities review, the Lab installed a water-level indicator in a vertical pipe at Building 704, which is part of the graphite reactor complex. Approximately 13 gallons of water were pumped out and sampled on October 15.
Also, BNL is beginning to pump out water from a canal in Building 830. An initial 6,000 gallons were pumped out, analyzed to verify compliance with drinking water standards for radioactive elements and metals, and released to the Lab's sanitary system.
All of the above activities are associated with priority-one facilities within the facilities review, which originally designated every one of the roughly 400 existing buildings and structures, 300 demolished buildings and 300 portable structures on the Lab site as either a priority-one or priority-two facility. Priority-one facilities used or generated significant quantities of radioactive material prior to the 1970s, when most environmental regulations and standards were developed and issued. Priority-two facilities are the balance of structures on site. BNL has just completed its review of priority-two facilities, and a draft report will be available to the public in November.
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