Index:Survey of Radionuclide Distributions Resulting from the Church Rock, New Mexico, Uranium Mill Tailings Pond Dam Failure OCR.pdf
| INTENTS
ACKNOWLEDGMENTS ABSTRACT 11l . v EXECUTIVE SUMMARY vi i INTRODUCTION 1 EXPERIMENTAL METHODS 5 SAMPLE COLLECTION 5 PREPARATION OF SAMPLES FOR INSTRUMENTAL ANALYSIS . INSTRUMENTAL ANALYSES OF RADIONUCLIDE CONCENTRATIONS Detector Types . . . . . . 6 8 . 8 Calibration of 9-in. Nal Well Crystal for 2 ^ 6 Ra quantitation , . . , . , , 8 Calibration of Intrinsic Germanium Detectors . 10 Selection of Counting Time Interval 10 Reporting of Uranium Analysis Data , 11 STATISTICAL METHODS Data Handling 1? . . Data Smoothing Functions . . . . . 12 . . . . . 13 EVALUATION Of INSTRUMENTAL COUNTING CAPABILITIES , 15 MEASUREMENT OF ^ 6 R a 15 EFFECT OF COUNTING TIME 17 REPLICATE COUNTING OF SAMPLES 19 21 RESULTS AND DISCUSSION ANALYSIS OF GRAND CANYON SAMPLES . PRESENTATION OF RIO PUERCG SAMPLE DATA XI . . . . 21 24 EVALUATION OF GRID SAMPLING DATA 21 EVALUATION OF BACKGROUND SAMPLES 41 ESTIMATION OF ^ T h INVENTORY 42 EVALUATION OF PUERCO SAMPLING STRATEGY 44 EVALUATION OF VERIFICATION SAMPLING PLAN AND PROPOSED CLEANUP CRITERIA 46 Number of Sample Replicates , , , , . EXPERIENCE GAINED FROM THE RTO PUERCO ENVIRONMENTAL STUDY . 49 53 . CONCLUSIONS 57 REFERENCES 59 APPENDIX A—NEW MEXICO ENVIRONMENTAL IMPROVEMENT DIVISION PROTOCOL FOR RIO PUERCO ENVIRONMENTAL SAMPLING . . . . A.l APPENDIX B—DATA FOR RIO PUERCO ENVIRONMENTAL SAMPLES B.l , APPENDIX C — 2 3 0 T h CONCENTRATIONS PLOTTED VERSUS RIO PUERCO DISTANCE DOWNSTREAM FROM SPILL SITE CI APPENDIX D—RIO PUERCO SAMPLING LOCATIONS D.l APPENDIX E—DATA FOR SITE VARIABILITY STUDIES . APPENDIX F—PROPOSED REVISED RIO PUERCO CLEANUP CRITERIA XI 1 . . . E.l F.l FIGURES 1. Rio Puerco Geographical Location . . . . . 3 2. . . . . . 7 Grand Canyon Sampling Locations 3. Typical Spectra from Intrinsic Germanium Diode Count of Soil Sample . . . . . . . . . . 4. 230jh Concentration Versus Distance . . . . 9 26 5. Rio Puerco Environmental VariaDility Study No. I 39 6. Rio Puerco Environmental Variability Study No. 2 40 TABLES 1. Representative Analysis of UNC Tailings Pond Solution 2 2. 2^6Ra Concentrations Measured in Sealed and Unsealed Samples 16 3. Effect of Counting Time on Precision of Sample Analysis 18 4. Variability of Short Counts on Individual Samples—1000-Sec Counting Time . , , . . . . , , , 20 5. Radionuclide Concentrations in Grand Canyon Samples—pCi/g , 21 6. Rio Puerco Background Samples 22 . . . . , . 7. Rio Puerco Samples Having 2^°Th Concentrations >30 pCi/g xm , 23 |
