U.S. Nuclear Regulatory Commission and U.S. Environmental Protection Agency.
Announce the issuance of three reports concerning radioactivity in sewage sludge and ash, and request public comments.
This Federal Register notice announces the availability of three reports, prepared by the Sewage Sludge Subcommittee of the Interagency Steering Committee on Radiation Standards (ISCORS), addressing radioactivity in sewage sludge and ash. The first report, “ISCORS Assessment of Start Printed Page 66504Radioactivity in Sewage Sludge: Radiological Survey Results and Analysis,” summarizes the information on radioactivity found in samples of sewage sludge and ash from 313 publicly owned treatment works (POTWs). This report is being issued as a final document, since it only presents data that has already been collected. The second report, “ISCORS Assessment of Radioactivity in Sewage Sludge: Modeling to Assess Radiation Doses,” assesses the potential levels of radiation doses to people by modeling the transport of radioactivity from sludge into the local environment. The report also provides a complete description and justification of the dose assessment methodology. The third report, “ISCORS Assessment of Radioactivity in Sewage Sludge: Recommendations on Management of Radioactive Materials in Sewage Sludge and Ash at Publicly Owned Treatment Works,” recommends further actions that may be taken by a POTW operator when elevated levels of radionuclides are detected.
The purpose of ISCORS is to foster early resolution and coordination of regulatory issues associated with radiation standards. Agencies represented on ISCORS include the U.S. Nuclear Regulatory Commission (NRC), the U.S. Environmental Protection Agency (EPA), the U.S. Department of Energy, the U.S. Department of Defense, the U.S. Department of Transportation, the Occupational Safety and Health Administration of the U.S. Department of Labor, and the U.S. Department of Health and Human Services. The Office of Science and Technology Policy, the Office of Management and Budget, and State representatives may be observers at meetings. The objectives of ISCORS are to: (1) Facilitate a consensus on allowable levels of radiation risk to the public and workers; (2) promote consistent and scientifically sound risk assessment and risk management approaches in setting and implementing standards for occupational and public protection from ionizing radiation; (3) promote completeness and coherence of Federal standards for radiation protection; and (4) identify interagency radiation protection issues and coordinate their resolution.
There have been a number of well-publicized cases of radionuclides discovered in sewage sludge and ash, and some of these have led to expensive cleanup projects. These incidents made clear the need for a comprehensive determination of the prevalence of radionuclides at publicly owned treatment works sewage sludge and ash around the country, and the level of potential threat posed to human health and the environment by various levels of such materials.
In response to this need, ISCORS formed a Sewage Sludge Subcommittee (SSS) to coordinate, evaluate, and resolve issues regarding radioactive materials in sewage sludge and ash. To estimate the amounts of radionuclides that actually occur in sewage sludge and ash, ISCORS' SSS performed a survey of radioactivity in sludge and ash across the United States. The final report is entitled, “ISCORS Assessment of Radioactivity in Sewage Sludge: Radiological Survey Results and Analysis,” and is available on the ISCORS Web site at http://www.iscors.org.
Concurrently, the Dose Modeling Workgroup of the SSS undertook a dose assessment to help assess the potential threat that these materials may pose to human health. The draft report that we are making available for public comment today, “ISCORS Assessment of Radioactivity in Sewage Sludge: Modeling to Assess Radiation Doses,” describes the methodology and results of the dose modeling effort. The general approach used in the report is a standard one that consists essentially of two steps. First, seven general, fairly generic scenarios (and some sub-scenarios) are constructed to represent typical situations in which members of the public of POTW workers are likely to be exposed to sludge. The selection of radionuclides for consideration was based on the results of the ISCORS survey of sewage sludge and ash at various POTWs, and includes manmade and naturally-occurring isotopes. Second, assuming a unit specific activity of a radionuclide in dry sludge, a widely accepted multi-pathway environmental transport model (the RESRAD family of codes) is employed to obtain sludge concentration-to-dose conversion factors.
A third and final document, “ISCORS Assessment of Radioactivity in Sewage Sludge: Recommendations on Management of Radioactive Materials in Sewage Sludge and Ash at Publicly Owned Treatment Works,” is also being issued for public comment today. This document is for use by POTW operators in evaluating whether the presence of radioactive materials in sewage sludge could pose a threat to the health and safety of POTW workers or the general public. ISCORS concludes that the levels of radioactive materials detected in sewage sludge and ash in the ISCORS survey indicate that, at most POTWs, radiation exposure to workers or to the general public is not likely to be a concern.
Comments on either, “ISCORS Assessment of Radioactivity in Sewage Sludge: Modeling to Assess Radiation Doses,” or “ISCORS Assessment of Radioactivity in Sewage Sludge: Recommendations on Management of Radioactive Materials in Sewage Sludge and Ash at Publicly Owned Treatment Works,” should be sent to the EPA contact listed below by February 6, 2004.
Robert Bastian, U.S. Environmental Protection Agency—4204M, 1200 Pennsylvania Avenue, NW., Washington, DC 20460, Telephone: 202-564-0653, e-mail: email@example.com.
Hard copies can also be obtained by calling or writing to Carol Walls, U.S. Nuclear Regulatory Commission, NMSS/DWM/EPAB, M.S. T-7J8, Washington, DC 20555-0001, 301-415-8028, or firstname.lastname@example.org.Start Further Info
FOR FURTHER INFORMATION CONTACT:
James Kennedy, U.S. Nuclear Regulatory Commission, NMSS/DWM, M.S. T-7J8, Washington, DC 20555, telephone 301-415-6668, fax 301-415-5397, e-mail email@example.com.Start Signature
Dated at Rockville, Maryland, this 20th day of November, 2003.
For The U.S. Nuclear Regulatory Commission.
John T. Greeves,
Director, Division of Waste Management, Office of Nuclear Material Safety and Safeguards.
[FR Doc. 03-29559 Filed 11-25-03; 8:45 am]
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