Correlating Neutron Energy Spectra with TLD Badge Response


W. S. Harris, Jr., M. A. Melanson, J. W. Tincher


The U.S. Army Dosimetry Laboratory has the responsibility of providing personnel dosimetry support to individuals exposed to ionizing radiation. Radiation workers are exposed to beta, gamma, x-ray, and neutron radiation over a wide range of energies. Neutron dosimetry presents challenges not associated with other types of radiation dosimetry. Complexities include monitoring personnel over a broad range of neutron energies, variations in neutron quality factors, and variations in dosimeter response as a function of neutron energy. In order to perform effective neutron dosimetry, the Army Dosimetry Laboratory performs onsite dosimetry evaluation of facilities that use neutron sources in order to determine a site specific neutron factor. This factor is used to determine the neutron dose equivalent for personnel at a particular location. This paper describes the procedures, radiation instrumentation, dosimeters, and onsite survey program the Army uses to provide personnel monitoring support for radiation workers exposed to neutron radiation. Los Alamos National Laboratory and Gutierrez-Palmenberg, Inc. implemented state-of-the-art radiation safety administration applications with access to Lab-wide Oracle databases called the Radiation Protection Automation System (RPAS). Radiation protection, operational, and management users are networked to a Microsoft Windows 2000 Server using Terminal Services. Design is based on Hazard, Access Control, Routine Monitoring, Posting, and regulatory matrices ensuring RPAS applicability for any radiation safety program. Radiation worker activities are reviewed, approved, and tracked by radiation work permits (RWPs), logbook worksheets, and daily electronic personal dosimeters (EPDs). RPAS administers and maintains the planned work schedules, charge codes, timesheets, controlled areas and postings, routine monitoring instructions and tasks, radiation surveys, survey maps, digital photos, count lab data and dosimeter data. All information can be sorted by time, RCT, worksheet, task type, and location to enable real time as low as reasonably achievable overview, program QA, and reporting. RWP, EPD, ALARA, survey, and administrative screens will be reviewed and discussed during the presentation. Testing and implementation challenges are also summarized.


This abstract was presented at the 34th Annual Midyear Meeting, "Radiation Safety and ALARA Considerations for the 21st Century", Personnel Surveillance Applications Session, 2/4/2001 - 2/7/2001, held in Anaheim, CA.

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