ORNL-5040 (CORRECTED) The KFM, A Homemade Yet Accurate and Dependable Fallout Meter Cresson H. Kearny Paul R. Barnes Conrad V. Chester Margaret W. Cortner ORNL-5040 (CORRECTED) Dist. Category UC-41 Contract No. V-7405-eng-26 ENERGY DIVISION THE KFM, A HOMEMADE YET ACCURATE AND DEPENDABLE FALLOUT METER Cresson H. Kearny Paul R. Barnes Conrad V. Chester Margaret W. Cortner Research sponsored by the Division of Biomedical and Environmental Research, Department of Energy, under contract with the Union Carbide Corporation. Date P-jblished: January 1978 OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37830 operated by UNION CAREI3E CORPORATION for the DEPARTMENT OF ENERGY iii CONTENTS Page LIST OF FIGURES v OAK RID(F NATIONAL LABORATORY DRAWINGS AND PHOTOGRAPHS USED IN ' INSTRUCTIONS vii ACKNOWLEDGMENTS ix ABSTRACT 1 i. THE NEED FOR TRUSTWORTHY FALLOUT METERS THAT UNTRAINED AMERICANS CAN QUICKLY MAKE AND USE 1 2. OBJECTIVES OF TUIS REPORT 3. PRIOR HOMEMADE FALLOUT INSTRUMENTS 5 4. BACKCROUND AND BASIC CAPABILITIES OF THE KEARNY FALUVJT METER (KFM) 6 5. FIELD-TESTED BUILDING AND OPERATING INSTRUCTIONS 7 5.1 Steps in the Development of the KFM Instructions . . .. 7 5.2 Objectives of Those Instructions 10 5.3 Uses of This Report as Regards Its KFM Instructions . . 11 HOW TO MAES AND USE A hOMEMADE FALLOUT METER, THE KFM INSTRUCTIONS FOR PERSONS CONCERNED WITH REPRODUCING THE KFM INSTRUCTIONS , (A) LAYOUT FOR 12-PAGE TABLOID (B) LOGO FOR TABLOID Page 1 I. THE NEED FOR ACCURATE AND DEPENDABLE FALLOUT METERS . . . Page 2 II. SURVIVAL WORK PRIORITIES DURING A CRISIS Page 2 III. HOW TO USE THESE INSTRUCTIONS TO BEST ADVANTAGE Page 2 IV. WHAT A KFM IS AND HOW IT WORKS Page 3 V. MATERIALS NEEDED Page 6 VI. US2F1JL BUT NOT ESSENTIAL MATERIALS Page 7 VII. TOOLS NEEDED Page 7 VIII. MAKE THE DRYING AGENT Page 7 IX. MAKE THE IONIZATION CHAMBfcR OF THE KFM Page 8 X. MAKE TWO SEPARATE 8-PLY LEAVES OF STANDARD (NOT HEAVY DUTY) ALUMINUM FOIL Page 10 XI. INSTALL THE ALUMINUM-FGIC LEAVES Page 14 BLANK PAGE iv Page XII. MAKE THE PLASTIC COVER Page 14 HII. TWO WAYS TO CHARGE A KFM Page 17 XIV. MAKE AND USE A DRY-BUCKET Page 19 XV. HOW TO USE A KFM AFTER A NUCLEAR ATTACIV. Par-: 20 A. Background Information Page 10 B. Finding the Dose Rate Page ::J C. Calculating the Dose Received Page 22 D. Estimating the Dangers fron: Different Doses . . .. Page 22 E. Using a KFM to Reduce the Doses Received Inside a Shelter P«ge 23 FOUR EXTRA PATTERN PAGES (for the recipient of this report to use in making KFMs, so as not to damage the camera-ready instructions) (unnumbered) 6. ACCURACY AND RANGE OF THE KFM 13 7. CONCLUSIONS AND REC^IMFNDATIONS 16 APPENDICES A. DESIGN PRINCIPLES AND PROCEDURES USED IN DEVELOPING THE KFM 17 B. ADDITIONAL TECHNICAL INFORMATION 23 B.l KFM Ionization Chambers 23 B.2 Range and Accuracy of Measurements 24 B.3 Aluminum-Foil Leaves 26 B.4 Insulating Threads 29 B.5 Drying Agent 30 B-6 Three Expedient Charging Devices 32 B.7 Charging a KFM in a Dangerously High Gamma Field . .. 35 B.3 Other Means fo" Charging KFMs and Similar Electroscope-Capacitors 3l V ,> LIST OF FIGURES 5.1 Winning Hands 8 5.2 Trimming Skirt of KFM Cover 8 6.1 Balanced Forces Operacing on the Charged Leaves of a KFM 13 6.2 Calibration Curves for Two KFMs with 8-Ply Leaves 14 6.3 Normalized Calibration Points for Two KFMs, Derived Graphically from Fig. 6.2 15 APPENDIX B.l Calibration Curves for Three KFMs 24 B.2 Data from Fig. B.l, Normalized and Graphed 25 B.3 Data Derived fro"i Normalized Calibration Curves 25 B.4 Aluminum-Foil Charger 34 B.5 Transferring Charge of an Aluminun-Fcil Charger 34 vii OAK RIDG£ NATIONAL LABORATORY DRAWINGS AND PHOTOGRAPHS USED Hi rHE INSTRUCTIONS Page ORNL-DWG 76-6532 Page 3 ORNL-DWG 76-6533 Page 3 ORNL-DWG 76-8739 Page 3 ORNL-PHOTO 6396-76 Page 4 ORNL-PHOTO 6395-76 Page 4 ORNL-PHOTO 0186-77 Page 4 ORNL-PHOTO 6393-76 Page 4 ORNL-DWG 75-.U588R Page 5 ORNL-DWG 76-6534 Page 8 ORNL-DWG 76-6537 Page 8 ORNL-DWG 76-6535 Page 9 ORNL-DWG 76-6538 Page 10 ORNL-DWG 76-6539 Page 10 ORNL-DWG 76-6540 Page 10 ORNL-DWG 76-6536 Page 11 ORNL-DWG 76-6542 Page 12 ORNL-DWG 76-6541 Page 13 ORNL-DWG 76-6543 Page 14 ORNL-DWG 77-10078 Page 15 ORKL-DWG 76-6544R Page 16 ORNL-DWG 76-6i45 Page 17 ORNL-PHOTO 6390-/6 Page 17 ORNL-DWG 76-6546 Page 18 ORNL-DWG 76-6547 Page 18 ORNL-PHOTO 1761-76 Page 19 ORNL-DWG 76-8675 Page 19 ORNL-DWG 76-8739 Page 21 ix ACKNOWLEDGMENTS The authors are indebted to Carsten M. Haaland for his recommen­ dation to use a quickly unwound roll of tape as a high-voltage charging device and to Marjorie E. Fish for suggesting 2nd developing the use of patterns to replace instructions for measuring and positioning parts of the KFM. We also appreciate the advice received from J. E. Jones an<* R. D. Smyser of The Oak Ridger and from H. J. Crouae and W. P. Allen of The Montirose Daily Press regarding the development of camera-ready copy of the instructions for making and using a KFM. The writing of this report was improved by George A. Cristy's numer­ ous constructive criticisms and recommendations, Ruby N. Thurmer's editorial assistance, and Walter S. Snyder's and D. B. Nelson's reviews and recommendations. THE KFM, A HOMEMADE YET ACCURATE AND DEPENDABLE FALLCUT METER Cresson H. Kearny Paul R. Barnes Conrar, V. Chester ^ Margaret W. lortner ABSTRACT The KFM is a homenad? fallout meter that can be made using only materials, tools, and skills found in millions of American homes. It is an accurate and dependable electroscope-capacitor. The KFM, in conjunction with its attached table and a watch, is designed for use as a rate meter. Its attached table relates observed dif­ ferences in the separations of its two leaves (before and after exposures at the listed time intervals) to the dose rates during exposures of these time intervals. In this manner dose rates from 30 mR/hr up to 43 R/hr can be determined with an accuracy of ±25Z. A KFM can be charged with any one of the three expe­ dient electrostatic charging devices described. Due to the use of anhydrite (made by heating gypsum from wall- board) inside a KFM and the expedient "dry-bucket" in which it can be charged when the air is very humid, this instrument always can be charged and used to obtain accurate measurements of gamma radiation no matter how high the relative humidity. The heart of this report is the step-by-stcp illus­ trated instructions for making and using a KFM. These instructions have been improved after each successive field test. The majority of the untrained test families, adequately motivated by cash bonuses offered for success and guided only by these written instructions, have succeeded in making and using a KFM. 1. THE NEED FOR TRUSTWORTHY FALLOUT METERS THAT UNTRAINED AMERICANS CAN QUICKLY MAKE AND USE If the.United States were to suffer a nuclear attack, most Americans — especially those outside the cities and therefore most likely to survive — would lack instruments to Inform them concerning the changing dose rates Graduate student, Vanderbilt University, Nashville, Tennessee. N •% BLANK PAGE i"