Mark D. Kauffman, P.E., ENSR International, 2 Technology Park Drive, Westford, MA  01886, Tel: 978-589-3119, Fax: 978-589-3100, Email: mkauffman@ensr.com
Shannon B. Gleason, P.E., ENSR International, 6 Meadow Way, Middlebury, VT  05753, Tel: 802-989-1164, Fax: 978-589-3100, Email: sgleason@ensr.com
Caryn Spiak, ENSR International, 2 Technology Park Drive, Westford, MA  01886, Tel: 978-589-3407, Fax: 978-589-3100, Email: cspiak@ensr.com
Barbara Newman, U.S. Army Corps of Engineers, New England District, 696 Virginia Road,
Concord, MA  01742, Tel: 978-318-8515, Fax: 978-318-8850, Email: Barbara.H.Newman@nae02.usace.army.mil

The Formally Utilized Sites Remedial Action Program (FUSRAP) was established in 1974 to cleanup or control radioactive residuals from prior US government operations, which were primarily conducted under the direction of the US Manhattan Engineer District (MED) and Atomic Energy Commission (AEC).  The US Army Corps of Engineers (Corps) is the lead federal agency for the administration of FUSRAP, and must ensure compliance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process.  Many FUSRAP site locations have ongoing commercial activities, and some are in the process of applying to the US Nuclear Regulatory Commission (NRC) for de-regulation (de-licensure). To reduce costs and improve program efficiency, the Corps works closely with those facilities to develop jointly acceptable cleanup goals, and to produce CERCLA documents that can also be used by the facilities to support their NRC de-licensure requirements.  At the Combustion Engineering Site in Connecticut, ENSR and the Corps augmented the standard project team of engineers and scientists, with health and nuclear physicists.  Gamma walkover surveys and an onsite laboratory provided real-time data to refine site boundaries and target sampling locations.  Measured uranium radioactivity was converted from energy units (such as pCi/g) to mass units (such as mg/kg) based on the specific activities of individual isotopes.  Enrichment was calculated using surrogate radionuclides (such as thorium) to estimate the presence of the U-238 isotope.  Risk assessment and derivation of cleanup levels for non-radioactive chemicals followed CERCLA guidance, while the dose assessment and calculation of derived concentration guideline levels (DCGLs) for radioactivity was modeled using the Residual Radioactivity (RESRAD) computer model.  The ultimate objective was a common cleanup goal, acceptable to all parties.

Influence of Home Size on the Risks from Soil-Gas and Waterborne Indoor Radon

George Saiway, M.S., Fiorella Simoni, M.S., Chemistry Department, George Mason University,Fairfax, VA 22030, Tel: 703-273-2282
Douglas Mose, Ph.D., George Mushrush, Ph.D., Center for Basic and Applied Science, 20099 Camp Road, Culpeper, VA 22701-7409, Tel: 703-273-2282, Email: Dje42@aol.com

In a recent study of @ 1000 homes in Virginia and Maryland, three month measurements of airborne radon derived from soil gas combined with indoor radon derived from potable water in the home ranged from @ 1-40 pCi/L. The radon in well water ranged from @ 100-8,000 pCi/L; the radon in reservoir water was less than 100 pCi/L. In a study set composed of small homes using well water, the indoor (airborne) radon concentration was related to waterborne radon concentration. Intermediate size homes showed a weaker correlation, and large homes did not show an airborne verses waterborne correlation. In the study set of all the homes using reservoir water (no waterborne radon), the indoor radon concentrations were not found to be correlated with home size. In terms of the risk of developing lung cancer, the greatest risk is experienced by people using well water while living in small homes.

Development of Radon Enrichment in Soil Gas over Quartz-Mica Schist in Virginia

Charles Chrosniak, Paul DiBenedetto, Chemistry Department, George Mason University, Fairfax, VA 22030, Tel: 703-273-2282 
Douglas Mose, Ph.D., George Mushrush, Ph.D., Center for Basic and Applied Science, 20099 Camp Road, Culpeper, VA 22701-7409, Tel: 703-273-2282, Email: Dje42@aol.com

A major portion of northern Virginia is underlain by a quartz-muscovite soil, approximately 10 meters thick, that has developed on a bedrock of polymetamorphic schist. The schist formed from an ancient clay-rich sediment, subsequently recrystallized several times as the modern Appalachian rocks were heated deep in the Earth, and subsequently exposed by erosion. The total-gamma radioactivity and the permeability of the schist are higher than average, and combine to generate a radon-rich soil-gas that can be brought into homes by the pressure differential normally present in the local homes that commonly are well-insulated and have basements. More than half of the homes, based on three-month measurements, exceed the U.S. Environmental Protection Agency recommended maximum for indoor radon of 4 pCi/L. Fortunately, while the area is experiencing a rapid increase in new home construction, it is possible to avoid areas of high soil-gas radon and high permeability, and to use home construction methods that can reduce soil-to-home movement of radon emanating from the soil.

Determination of Natural Ra Isotopes in Samples from Northern São Paulo State Coastal Area

Washington E. Teixeira, Production Engineering Anhembi Morumbi University, Rua Casa do Ator, 90, São Paulo, 04546-000 Brazil, Tel: 55-11-6440-1287, Fax: 55-11-6443-4805, Email: wweteixeira@aol.com
Joselene de Oliveira, Center of Radiation Metrology, Environmental Radiometer Division, IPEN, Instituto de Pesquisas Energeticas e Nucleares, Av. Prof Lineu Prestes, 2242, Cidade Universitária, São Paulo, 05508-000 Brazil, Tel: 55-11-3816-9000, Fax: 55-11-3812-3546

The present work aims at implementing and confirming an analytical methodology which allows to determinate the natural isotopes of radium concentrations in seawater samples in which these natural radionuclides are present in trace form. The technique which will be developed is based on the pre-heating of huge volumes of sea water in acrylic fibers impregnated with MnO₂ acid lixiviation with concentrate HCl, and co-precipitation radio isotopes with BaSO₄.

Before long-lived radium isotopes determination, the isotopes ²²³Ra e ²²⁴Ra (short -lived) were quantified using delayed coincidence system.  This system pioneered by Giffin et al. (1963) and adapted for Ra measurements by Moore e Arnold (1996). The delayed coincidence system utilizes the difference in decay constants of the short-lived Po daughters of radon ²¹⁹Rn and ²²⁰Rn to identify alpha particles derived from ²¹⁹Rn and ²²⁰Rn decay.

The activities of ²²⁶Ra and ²²⁸Ra will be determined by alpha and beta total counting respectively from the Ba(Ra) SO₄  precipitate in a proportional detector of gas flow of background low radiation.  

The results obtained in this research will be used in a more extensive work to quantify the underground water discharge in the studied sea environment and the rates of water masses mixture from the coastal region to the ocean.

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