ORAU TEAM Dose Reconstruction Project for NIOSH Oak Ridge Associated Universities I Dade Moeller & Associates I MJW Corporation Page 1 of 72 Document Title: Document Number: ORAUT-OTIB-0046 Revision: 00 Historical Evaluation of the Film Badge Dosimetry Effective Date: 06/22/2007 Program at the Y-12 Plant in Oak Ridge, Tennessee: Part 3 – Beta Radiation Type of Document: OTIB Supersedes: None Subject Expert(s): George D. Kerr, Edward L. Frome, Janice P. Watkins, and William G. Tankersley Site Expert(s): N/A Approval: Signature on File Approval Date: 06/06/2007 William G. Tankersley, Document Owner Concurrence: Signature on File Concurrence Date: 06/05/2007 John M. Byrne, Task 3 Manager Concurrence: Signature on File Concurrence Date: 06/05/2007 Edward F. Maher, Task 5 Manager Concurrence: Signature on File Concurrence Date: 06/12/2007 Kate Kimpan, Project Director Approval: Brant A. Ulsh Signature on File for Approval Date: 06/22/2007 James W. Neton, Associate Director for Science New Total Rewrite Revision Page Change FOR DOCUM ENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION. Document No. ORAUT-OTIB-0046 Revision No. 00 Effective Date: 06/22/2007 Page 2 of 72 PUBLICATION RECORD EFFECTIVE REVISION DATE NUMBER DESCRIPTION 06/22/2007 00 New technical information bulletin that provides background information on the Y-12 external dosimetry program related to film badge monitoring of beta radiation. Incorporates formal internal and NIOSH review comments. Attributions and Annotations section added. Added references and made editorial changes. No further changes occurred as a result of formal internal and NIOSH review of the Attributions and Annotations section. There is no change to the assigned dose and no PER is required. Training required: As determined by the Task Manager. Initiated by George D. Kerr. Document No. ORAUT-OTIB-0046 Revision No. 00 Effective Date: 06/22/2007 Page 3 of 72 TABLE OF CONTENTS SECTION TITLE PAGE Acronyms and Abbreviations .............................................................................................................6 1.0 Introduction ...........................................................................................................................8 2.0 Purpose.................................................................................................................................8 3.0 Film Badge Dosimetry at the Y-12 Plant .................................................................................9 3.1 1947 to 1949 ............................................................................................................... 12 3.2 1950 to 1951 ............................................................................................................... 13 3.3 1952 to Mid-1956 ........................................................................................................ 14 3.4 Mid-1956 to 1961 ........................................................................................................ 15 3.5 1961 to 1979 ............................................................................................................... 16 4.0 Major Sources for Exposures to Beta Particles at the Y-12 Plant........................................... 16 4.1 Natural Uranium .......................................................................................................... 17 4.2 Depleted Uranium ....................................................................................................... 17 4.3 Enriched Uranium ....................................................................................................... 19 4.4 Thorium ...................................................................................................................... 21 4.5 Uranium-233 ............................................................................................................... 21 5.0 Film Badge Response to Different Sources of Beta Particles ................................................ 21 6.0 Y-12 External Dose Database .............................................................................................. 26 6.1 Data Delivered to the ORAU Center for Epidemiologic Research ................................. 26 6.2 Subgroup Data for Regression Analysis of Beta Doses ................................................ 26 7.0 Statistical Methods............................................................................................................... 27 7.1 Maximum Likelihood Estimates for Quarterly Data ....................................................... 27 7.2 Regression Analysis and the Prediction Density........................................................... 28 7.3 Nonparametric Analysis Using Modified Boxplots......................................................... 29 8.0 Use of Film Badge Measurements to Evaluate Beta Doses Over Time.................................. 30 8.1 All Quarterly Beta Doses ............................................................................................. 30 8.2 Quarterly Beta Doses for Two Large Y-12 Departments ............................................... 33 8.3 Limitations of Doses for Dose Reconstruction .............................................................. 34 9.0 Estimates for Unmonitored Quarterly Beta Doses ................................................................. 38 9.1 Procedure Used Through Fourth Quarter of 1955 ........................................................ 38 9.2 Procedure Used After Fourth Quarter of 1955 .............................................................. 40 9.3 Parameters for Lognormal Prediction Densities............................................................ 42 9.4 Scaling Procedure Based on Maximum Likelihood Method........................................... 42 9.5 Application of the Scaling Procedure ........................................................................... 44 9.6 Examples of Application of Regression Model and Scaling Procedure .......................... 45 10.0 Discussion ........................................................................................................................... 46 11.0 Attributions and Annotations ................................................................................................ 50 Document No. ORAUT-OTIB-0046 Revision No. 00 Effective Date: 06/22/2007 Page 4 of 72 References ..................................................................................................................................... 52 Attachment A, Lognormal Quantile-Quantile Plots for Quarterly Beta Doses ..................................... 59 LIST OF TABLES TABLE TITLE PAGE 3-1 Skin dose rates for slabs of natural uranium used in film badge calibrations at the Y-12 Plant ............................................................................................... 10 3-2 MDLs and assigned MDL doses for film badge dosimeters used to measure beta and gamma radiation exposures at the Y-12 Plant.......................................... 12 3-3 Historical monitoring techniques and routine exchange frequencies for external radiation dosimeters at the Y-12 Plant..................................................................... 12 3-4 Historical radiation protection guidelines for the Y-12 Plant ................................................... 14 4-1 Chronology of metal processing and fabrication at the Y-12 Plant during the film badge dosimetry program, 1947 to 1979 .................................................................. 17 4-2 Maximum energies and intensities of the beta particles from common radiation sources at the Y-12 Plant....................................................................................... 19 4-3 Properties of nuclear explosive nuclides ............................................................................... 20 6-1 Job activities and duties for 182 long-term Y-12 workers selected for regression analysis of beta doses ........................................................................................ 27 6-2 Comparison of job activities and duties for long-term Y-12 workers selected for regression analysis of gamma and beta doses................................................... 28 8-1 PLE summary statistics for Y-12 quarterly beta doses, 1952 to 1979 .................................... 31 8-2 MLE summary statistics for Y-12 quarterly beta doses, 1956 to 1965 .................................... 39 9-1 MLEs of regression parameters ........................................................................................... 40 9-2 Parameters for lognormal prediction density, 1947 to 1965 ................................................... 41 9-3 Calculation of scaling factor for Section 9.4 example ............................................................ 44 Document No. ORAUT-OTIB-0046 Revision No. 00 Effective Date: 06/22/2007 Page 5 of 72 LIST OF FIGURES FIGURE TITLE PAGE 3-1 Range of beta particles in skin as calculated with the ESTAR computer program............................................................................................................................... 11 4-1 Estimated dose rates from beta particles at the surface of a semi-infinite slab of uranium metal for various enrichments of 235U ........................................................... 18 5-1 Energy spectra of beta particles from the decay products of NU as