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Hanford Technical Basis for Multiple Dosimetry Effective Dose Methodology

Description: The current method at Hanford for dealing with the results from multiple dosimeters worn during non-uniform irradiation is to use a compartmentalization method to calculate the effective dose (E). The method, as documented in the current version of Section 6.9.3 in the 'Hanford External Dosimetry Technical Basis Manual, PNL-MA-842,' is based on the compartmentalization method presented in the 1997 ANSI/HPS N13.41 standard, 'Criteria for Performing Multiple Dosimetry.' With the adoption of the ICRP 60 methodology in the 2007 revision to 10 CFR 835 came changes that have a direct affect on the compartmentalization method described in the 1997 ANSI/HPS N13.41 standard, and, thus, to the method used at Hanford. The ANSI/HPS N13.41 standard committee is in the process of updating the standard, but the changes to the standard have not yet been approved. And, the drafts of the revision of the standard tend to align more with ICRP 60 than with the changes specified in the 2007 revision to 10 CFR 835. Therefore, a revised method for calculating effective dose from non-uniform external irradiation using a compartmental method was developed using the tissue weighting factors and remainder organs specified in 10 CFR 835 (2007).
Date: August 1, 2010
Creator: Hill, Robin L. & Rathbone, Bruce A.
Partner: UNT Libraries Government Documents Department

Comparison of radiological dose pathways for tank farm accidents

Description: This calculation note documents an evaluation of the doses from submersion and ground shine due to a release of tank farm radioactive materials, and a comparison of these doses to the doses from inhalation of the materials. The submersion and ground shine doses are insignificant compared to the inhalation doses. The doses from resuspension are also shown to be negligible for the tank farm analysis conditions.
Date: October 30, 1996
Creator: Van Keuren, J.C.
Partner: UNT Libraries Government Documents Department

Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: results for CY 1993 and CY 1994

Description: In January 1993, Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM)(DOE 1994). The purpose of the program was to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. Article 51 1. la of the RCM requires issuance of personnel dosimeters if individuals are likely to receive a dose of at least 100 mrem annually. The area monitoring TLD program was a useful tool in determining exposure trends in work areas located outside of radiological areas. In several situations, the information obtained from this program was used to relocate staff or radioactive material resulting in potential dose reductions for staff.
Date: March 1996
Creator: Bivins, S. R. & Stoetzel, G. A.
Partner: UNT Libraries Government Documents Department

Laboratory measurement error in external dose estimates and its effects on dose-response analyses of Hanford worker mortality data

Description: This report addresses laboratory measurement error in estimates of external doses obtained from personnel dosimeters, and investigates the effects of these errors on linear dose-response analyses of data from epidemiologic studies of nuclear workers. These errors have the distinguishing feature that they are independent across time and across workers. Although the calculations made for this report were based on Hanford data, the overall conclusions are likely to be relevant for other epidemiologic studies of workers exposed to external radiation.
Date: August 1, 1996
Creator: Gilbert, E.S. & Fix, J.J.
Partner: UNT Libraries Government Documents Department

Effects of radioactive hot particles on pig skin

Description: The purpose of these studies was to determine the incidence and severity of lesions resulting from very localized deposition of dose to skin from small (< 0.5 mm) discrete radioactive particles as produced in the work environments of nuclear reactors. Hanford mini-pigs were exposed, both on a slightly off the skin, to localized replicate doses from 0.31 to 64 Gy (averaged over 1 cm{sup 2} at 70 {mu}m depth unless noted otherwise) using Sc-46, Yb-175, Tm-170, and fissioned UC{sub 2} isotopes having maximum beta-particle energies from about 0.3 to 3 MeV. Erythema and scabs (indicating ulceration) were scored for up to 71 days post-irradiation. The responses followed normal cumulative probability distributions, and therefore, no true threshold could be defined. Hence, 10 and 50% scab incidence rates were deduced using probit analyses. The lowest dose which produced 10% incidence was about 1 Gy for Yb-175 (0.5 MeV maximum energy) beta particle exposures, and about 3 to 9 Gy for other isotopes. The histopathology of lesions was determined at several doses. Single exposures to doses as large as 1,790 Gy were also given, and results were observed for up to 144 days post-exposure. Severity of detriment was estimated by analyzing the results in terms of lesion diameter, persistence, and infection. Over 1,100 sites were exposed. Only two exposed sites became infected after doses near 5000 Gy; the lesions healed quickly on treatment. 105 refs., 145 figs., 47 tabs.
Date: June 1997
Creator: Kaurin, D. G.; Baum, J. W. & Schaefer, C. W.
Partner: UNT Libraries Government Documents Department

Protective measures for personnel

Description: This document addresses radiation protection concerns for workers in the experimental laboratories and production plants where nuclear fission piles are being used. A broad in-depth discussion is provided based with the experiences gained in the Manhattan Project and being applied to contemporary activities. Discussion is thorough and encompasses control of external irradiations including alpha, beta, gamma, and neutron radiations; and control of radioactivity within the body by control of inhalation, ingestion, and entrance through skin or wounds. General measures for the control of radiation hazards is addressed by provision of clothing and waste disposal. An Appendix 1 is entitled General Rules and Procedures Concerning Activity Hazards.
Date: December 13, 1946
Creator: Nickson, J.J.
Partner: UNT Libraries Government Documents Department

Probabilistic Performance Assessment of a Low-Level Radioactive Waste Disposal Site on the Nevada Test Site

Description: The Area 5 Radioactive Waste Management Site on the Nevada Test Site has been disposing of low-level, mixed low-level, and transuranic radioactive waste since 1961. In 1988, the U.S. Department of Energy implemented performance objectives for low-level radioactive waste disposal site performance and required all site operators to prepare a performance assessment. Since then, an iterative performance assessment process has been implemented that consists of repeated cycles of site characterization, conceptual model formation/revision, and performance assessment modeling. At the end of each cycle uncertainty and sensitivity analysis are used to determine the need for revision and to identify topics requiring additional research and development. The performance assessment model is implemented in the GoldSim{reg_sign} probabilistic simulation platform. The current site conceptual model, based on site characterization data and process model results, assumes that there is no groundwater pathway under current climatic conditions and that radionuclide releases are predominately upward to the land surface. Radionuclides are released to the land surface by upward liquid advection/diffusion, gas diffusion, biointrusion, and inadvertent human intrusion. The model calculates dose for four members of public exposure scenarios and two intruder scenarios. The highest mean-dose, 0.04 mSv yr{sup -1}, is expected for a low-probability exposure scenario: establishment of a rural community at the site boundary at the end of institutional control. At the end of institutional control, doses are contributed primarily by {sup 3}H in agricultural products produced onsite. After approximately 300 years, the doses are contributed equally by {sup 99}Tc and {sup 210}Pb ingested in vegetables grown at the residence. Technetium is released to the surface by the coupled processes of liquid advection/diffusion occurring deep in the cover and plant uptake/animal burrowing occurring at shallower depths. Lead-210 is deposited in shallow cover soil by the radioactive decay of {sup 222}Rn diffusing in the gas phase. The ...
Date: March 1, 2008
Creator: Shott, G. J.; Yucel, V. & Desotell, L. T.
Partner: UNT Libraries Government Documents Department

Ninth year progress report, August 1, 1972--July 31, 1973

Description: Rats that received 100 R of in utero x irradiation on the eighteenth day of gestation survived hypothalamic electrode implantation poorly; exhibited a diminished response to hypothalamic stimulation; and showed no significant difference in their preand post-tongue radiation saccharin taste threshold. (auth)
Date: January 1, 1973
Creator: Shaber, G.S.
Partner: UNT Libraries Government Documents Department

Calculations of the absorbed dose to a man immersed in an infinite cloud of $sup 85$Kr

Description: The dosimetry for a person exposed to a large cloud of /sup 85/Kr, supposed to be uniformly distributed in air, is considered. Methods are described that are general, and will also apply to exposure to an infinite cloud of other noble gases. Computer calculations are used for estimates of dose in an anthropomorphic phantom. The decay scheme of /sup 85/Kr which is taken from MIRD Pamphlet No. 6 is included. There is only one photon and its intensity is only 0.41% per disintegration. (auth)
Date: January 1, 1973
Creator: Snyder, W.S.; Dillman, L.T.; Ford, M.R. & Poston, J.W.
Partner: UNT Libraries Government Documents Department

Rational approach to patient exposure to radiation in the hospital

Description: During radiotherapy for the treatment of neoplasms the radiation dose needs to be selected with great care and the treatment needs to be carried out with a high degree of precision and accuracy for maximum results. Data are presented on the probability of tumor control of Hodgkin's disease and carcinoma of the supraglottis following radiation treatment. The x radiation dose to patients during various diagnostic radiographic examinations is discussed and several methods are suggested for dose reduction. (CH)
Date: January 1, 1975
Creator: Lanzl, L. H. & Moser, F. L.
Partner: UNT Libraries Government Documents Department

Determination of the secondary electron equilibrium using an extrapolation chamber

Description: To ensure that the external personnel dosimetry program conducted by U. S. Department of Energy (DOE) contractors is of the highest quality, the DOE established the Department of Energy Laboratory Accreditation Program or DOELAP. The contractor`s dosimetry program is assessed against the criteria set forth for dosimeter performance and the associated quality assurance and calibration programs. Although personnel dosimeters are not processed or calibrated by Fermilab, a proactive quality assurance program is in place to ensure accurate monitoring. This program includes quarterly blind testing of the dosimeters used by personnel. During the on-site assessment conducted of Fermilab`s external dosimetry program during May 1994, an observation with regard to equipment maintenance and calibration was made: ``calibration personnel should probably review the electron secondary equilibrium needs at various irradiation distances from the {sup 137}Cs irradiation systems`` The majority of the secondary electrons are generated through interactions of the beam with the collimator. Secondary electrons increase the low energy component of the radiation field, increasing the shallow doses measured. For dosimetric purposes, this increase needs to be defined so appropriate corrections to calculations or modifications to the facility can be made. Prompted by this observation, a study was designed to investigate the electron secondary equilibrium in the facility used for the blind testing by determining the dose equivalent as a function of depth in a tissue-equivalent medium. This presentation summarizes the methodology utilized and results of the investigation.
Date: September 1, 1996
Creator: Marshall, E.T.; Vaziri, K.; Krueger, F.P. & Cossairt, J.D.
Partner: UNT Libraries Government Documents Department

1963 revisited: should we set a precedent of recalculating old exposures

Description: This paper describes recent experience in re-evaluating the dose to an employee. This employee was plagued with skin disorders for years, but he questioned his recorded beta dose only after a recent LLNL cancer study began collecting data. He was concerned that his radiation dose recorded during the time he worked on a fission burst reactor experiment in 1963 did not represent the actual dose he received. About six months were spent gathering information, putting the information together, making necessary calculations, and reaching a reasonable result (a reasonable result being one for which the known information fits the calculated results with a minimum of inconsistencies). This paper presents the beta and gamma whole-body and hand radiation dose calculations, and compares these calculated dose rates with the meter, film, and pocket dosimeter information recorded in the health and safety log, operation log, and dosimetry record.
Date: October 26, 1981
Creator: Hoots, S.S.
Partner: UNT Libraries Government Documents Department