#98-43

Issued April 29, 1998

 

BNL RELEASES 1996 ENVIRONMENTAL SUMMARY

 

UPTON, NY - The U.S. Department of Energy's Brookhaven National Laboratory has published its Site Environmental Report for the year 1996. The report presents the results of BNL's environ-mental monitoring program and provides an assessment of the Lab's environmental impact in 1996.

The report shows that the Laboratory's pollution-prevention efforts continued to reduce emissions to air and surface water in 1996. It also reports the results of routine testing for chemical and radioactive contaminants in fish, shellfish, deer, vegetation, sediment, groundwater and surface water on and near BNL's 5,300-acre campus.

Using these testing data and conservative assumptions, the report calculates the maximum potential radiation dose for a member of the public from BNL through any of these sources. These calculations assume that all radioactivity detected originated from BNL operations, and that an individual was exposed to the highest level detected during the year.

Doses were calculated for the following pathways: air, drinking water, fish and deer meat. The maximum hypothetical dose from any of those pathways was approximately five percent of the 100-millirem federal limit for public radiation exposure from BNL operations. The average individual's annual radiation dose from natural sources is approximately 300 millirems.

None of the pathways influenced by BNL constitutes a significant radiation dose to humans.

Among the testing data are results from ongoing monitoring of areas of the BNL site where past activities caused groundwater, soil and sediment contamination. Such areas are already being addressed under BNL's Superfund cleanup program, in cooperation with the New York State Department of Environmental Conservation, the U.S. Environmental Protection Agency and DOE. Ongoing monitoring helps guide the Superfund process.

The report is the latest in a series of annual summaries that BNL has issued nearly continuously since the early 1960s. Data summarized in the report were obtained through testing performed by BNL or contractor laboratories, the Suffolk County Department of Health Services, the New York State Department of Health and NYSDEC. To obtain a copy of the report, or a summary booklet, call (516) 344-2345 or visit a library near BNL.

Environmental Monitoring

The Laboratory conducts an extensive monitoring program, both at the point of release and at many locations on and off the site, to demonstrate that operations are in compliance with appropriate permits and standards for release. Environmental monitoring is also performed to assess the fate of contaminants released to the environment and to evaluate potential exposure to people from various pathways such as consumption of fish or water.

This monitoring has been reported annually since 1971 and provides a valuable resource in identifying long-term trends associated with BNL activities. These trends indicate a steady reduction of BNL releases to the environment. This effort to reduce releases is a major commitment of BNL.

Airborne Releases

BNL holds 62 permits issued by regulators for non-radiological airborne emissions from various point sources, including the Laboratory's steam plant. In 1996, all of these airborne emissions were in compliance with the U.S. Environmental Protection Agency's Clean Air Act.

The Laboratory also emits small amounts of radioactive elements to the air. Most of these emissions originate from the Lab's two research reactors, both of which operated during 1996, and from a facility where radioisotopes are made for medical research and treatment. In 1996, the principal radionuclides released were argon-41, oxygen-15 and tritium. The maximum public dose from these emissions was 0.07 millirem, a small fraction of the EPA public dose limit of 10 millirems per year for air releases. This dose assumes continuous exposure outdoors at the BNL site boundary.

Liquid Discharges

Liquid discharges from Lab operations are released to the environment either as surface-water releases to the Peconic River through the BNL sewage treatment plant or as direct releases from certain facilities to one of seven recharge basins on the property. Discharges to the sewage treatment plant are monitored daily, while discharges to the recharge basins are monitored monthly or quarterly. All discharges are regulated either by New York State or by DOE.

Levels of radioactive elements in discharges from the sewage treatment plant to the Peconic River met all limits in 1996. Tritium in this effluent, which originates in the building housing the High Flux Beam Reactor, was at an all-time low due to tritium reduction efforts by reactor staff. The highest one-day concentration of tritium in BNL effluent all year was about 5,000 picocuries per liter (pCi/L), one-quarter the EPA drinking water standard. The average monthly concentration was just over 1,300 pCi/L. A total of just over one curie of tritium was released in sewage plant effluent in all of 1996.

Discharges from the sewage treatment plant were monitored and reported for 27 non-radioactive parameters. Compliance with the NYSDEC permit for these discharges is excellent. Occasionally, results of specific samples may lie above BNL's discharge limits. Investigations and corrective actions are made in such cases. Most of the exceedences in 1996 were related to the very dilute nature of the BNL influent to the plant, which makes it difficult to meet limits for biological oxygen demand (BOD) and suspended solids. BOD describes the amount of oxygen consumed by microorganisms in a sample of effluent. A plan to reduce unnecessary water in the plant's influent has been prepared and submitted to NYSDEC.

Liquid stormwater and non-contact cooling water discharged to the seven on-site recharge basins showed trace quantities of radioactivity on an infrequent basis. The levels were all small fractions of the applicable standards.

Groundwater

BNL tests groundwater for radiological and non-radiological parameters using 220 monitoring wells on site and 40 monitoring wells off site, as well as 25 private drinking water wells.

As part of a cooperative program that began in 1985 with the Suffolk County Department of Health Services, 25 off-site private potable wells located in Manorville, east of BNL, were sampled for radionuclides in 1996. As has been reported in previous years, detectable quantities of tritium were found in six of the private wells, with the average concentration at about one-eighth of the EPA drinking water standard. The tritium in this groundwater is known to have originated in effluent from the BNL sewage treatment plant in years when tritium levels were higher than today, though still within annual average limits set by environmental authorities. Consumption of two liters per day of the water with the highest tritium concentration would result in a dose of 0.18 millirem.

There are areas of the BNL site where radioactivity levels in groundwater are above the relevant drinking water standards. In those areas, NYSDEC, EPA and DOE are working together with BNL to formulate and carry out remediation plans. Water in these locations does not serve as drinking water either on or off the BNL site.

An additional area of radioactive groundwater contamination was found as a result of samples taken in 1996. In October 1996, BNL staff took the first water samples from two new monitoring wells immediately south of the High Flux Beam Reactor building. When the analysis was received in December 1996, one sample was found to contain tritium at one-tenth the drinking water standard. Because tritium above background levels had not been expected, further samples were taken in late December in an attempt to confirm the initial analysis. The results of those samples, showing tritium at twice the drinking water standard in one well, were received in early 1997.

After the results had been confirmed through further testing, BNL and DOE teamed with county, state and federal regulators in a full-scale investigation that found a plume of tritium groundwater contamination extending several thousand feet south of the HFBR building. This investigation led to an interim remediation project to prevent the tritium from leaving the site, and resulted in actions to address the source of the plume, the HFBR spent-fuel pool. The plume continues to be addressed under Superfund, and the HFBR is not operating pending a DOE decision on its future.

Nonradiological sampling of groundwater at BNL in 1996 continued to show metals and volatile organic compounds exceeding state standards in a number of locations on and off site, which were generally traceable to past activities, such as known spills or waste storage and former disposal areas. Again, these locations are being addressed under Superfund.

As a precaution against potential future chemical contamination of private wells at levels above drinking water standards by these off-site chemical plumes, DOE is providing a free connection to the public water supply to each home in a specified area around BNL, including the area where tritium is found in private wells.

Water, Fish, Shellfish, Deer, Soil, Sediment and Vegetation

In order to assess the impact of past and current BNL emissions on local wildlife, BNL and several regulatory agencies conduct a wide range of sampling programs. In 1996, these programs collected and analyzed fish, shellfish, deer, soil, sediment and vegetation at BNL, near the site and in locations further from BNL that could act as comparison sites.

Peconic River, Superfund testing: In 1996, some of the sampling of fish and sediment in the Peconic River at BNL and immediately downstream was conducted for the Superfund program. A full report on the results of this testing will be available later this year. Partial results reported in the 1996 Site Environmental Report show low levels of americium, cobalt, cesium and strontium in sediment on the Lab site, and detectable levels of radionuclides in some fish on the Lab site. With the exception of tritium, all of these radioactive elements are largely present due to past BNL activities.

Surface water, non-Superfund: NYSDEC collected sediment, water, vegetation and fish in the Peconic River and nearby ponds, as well as at comparison locations not impacted by BNL that included Carmans River and Fresh Pond in Montauk. The 1996 sampling covered more locations than previous years and, as in the past, showed low levels of cesium and strontium.

These results are not unexpected and are attributable to global weapons-testing fallout. It is of interest to note that concentrations of cesium-137 in fish in a pond just downstream of BNL are lower than those in fish from Fresh Pond, 60 miles from BNL. While BNL's releases over the years have resulted in additional low-level radioactivity in portions of the Peconic River near the site, this year's monitoring program indicates that the concentrations of radionuclides in the local environment falls within the normal range of radionuclide concentrations found in other local ecosystems on Long Island. Further testing at more locations is planned for 1998.

In addition to the NYSDEC sampling, the New York State Department of Health has sampled fish in the Peconic River system for over 20 years. Their report issued in 1996 stated that concentrations of cesium-137 in those fish have declined since the 1970s.

Based on the 1996 sampling and analysis for the radionuclides cesium-137 and strontium-90, the dose that a person would receive from eating 15 pounds of fish containing radionuclides at the highest concentration seen in a Peconic-fed pond in 1996 would be 0.46 millirem. This value uses assumptions recommended by NYSDEC, including that the radioactivity in the fish is solely attributable to BNL.

These assumptions are very conservative, particularly in light of the sampling results showing higher concentrations in some off-site locations not impacted by BNL. This dose would be in addition to the internal dose of about 40 millirems that a person receives annually from naturally occurring radionuclides in foods.

Sediment tests from six off-site locations showed levels of radionuclides in ponds directly downstream of BNL that were similar to levels in comparison ponds not fed by the Peconic River.

Shellfish Testing: In 1996, BNL tested clams and mussels from the Flanders Bay/Peconic Bay system downstream of BNL, and from a comparison location in Lloyd's Harbor/Northport Bay. No man-made radionuclides were found in either location.

Deer Testing: In conjunction with NYSDEC, BNL measured deer on and off the Lab site for radioactivity. The ten on-site meat and liver samples came from deer that had been killed in automobile accidents; hunting is prohibited on the BNL site. NYSDEC provided nine meat and liver samples from deer from off site. Similar, but less extensive, studies have been reported in 1986 and 1993.

As in earlier years, and as might be expected because of the presence of low-level cesium in soils at some locations at BNL, cesium-137 concentrations in deer meat were greater in deer sampled on the BNL site compared to those sampled off site. Cesium-137 concentrations averaged 6 picocuries per gram (pCi/g) and ranged from as low as 1.01 pCi/g to as high was 11.74 pCi/g in the five samples of deer meat taken from on site. Concentrations in the liver were lower. No other man-made radioactivity was found in the meat. The concentration of cesium seen in all deer is low and is not harmful to the deer or potential predators.

If an individual were to consume 20 pounds of the deer meat with the highest concentration of cesium found in a deer on-site, he or she would receive a radiation dose of 5 millirems per year. It should be noted that hunting is not allowed on the BNL site and that the general pattern for deer in the vicinity of the Lab site is to migrate onto the site because of favorable conditions.

Farm Testing: Soil and vegetation in local farms around the Lab site were sampled in June 1996 as part of a cooperative program between BNL and SCDHS. No radionuclides attributable to BNL operations were detected in any of the samples above background levels, although radionuclides from natural sources and weapons test fallout were found.

Summary

For the year 1996, BNL has calculated the maximum hypothetical dose from four pathways: air, water, fish and deer. Because of the conservative nature of the calculations, it is unlikely that any individual received the maximum dose calculated from any one pathway, and implausible that any individual received the sum of the individual pathways.

To put the doses in perspective, an individual on Long Island receives an annual dose of about 300 millirems from natural background radiation. Radioactive materials are found in cosmic rays (a dose of 24 millirems), the earth (36 millirems), in food and water (40 millirems) and radon (up to 200 millirems). In addition, the average dose to an individual in our society from medical exposures is approximately 50 millirems per year.

Brookhaven National Laboratory creates and operates major facilities available to university, industrial and government personnel for basic and applied research in the physical, biomedical and environmental sciences, and in selected energy technologies. The Laboratory is operated by Brookhaven Science Associates, a not-for-profit research management company, under contract with the U.S. Department of Energy.

 

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