ORNL/TM-2000/242

Chemical Technology Division

Strategy for Characterizing Transuranics and Technetium Contamination

in Depleted UF6 Cylinders

J. R. Hightower D. G. O’Connor‡ L. R. Dole S. J. Pawel§ D. W. Lee* R. L. Schmoyer* G. E. Michaels† L. D. Trowbridge M. I. Morris V. S. White‡

*Energy Division, ORNL †Nuclear Technology Program Office, ORNL ‡Engineering Technology Division, ORNL §Metals and Ceramics Division, ORNL

October 2000

Prepared by the OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831-6285 managed by UT-BATTELLE, LLC for the U.S. DEPARTMENT OF ENERGY under contract DE-AC05-00OR22725 CONTENTS

ACRONYMS AND ABBREVIATED FORMS ...... v

EXECUTIVE SUMMARY...... vii

1. DESCRIPTION OF PROBLEM...... 1

2. CONCLUSIONS AND RECOMMENDATIONS ...... 2

3. BACKGROUND INFORMATION ON Pu, Np, AND Tc CONTAMINATION ...... 3 3.1 CHEMICAL BEHAVIOR OF Am, Np, Pu, AND Tc ...... 3 3.2 KNOWN SAMPLING RESULTS ...... 4

3.3 ESTIMATED CONCENTRATIONS DISPERSED IN UF6 AND IN FEED HEELS ...... 9 3.4REGULATORY CRITERIA...... 10 3.4.1 U.S. Department of Transportation ...... 10 3.4.2 International Atomic Energy Agency ...... 11 3.4.3 U.S. Nuclear Regulatory Commission ...... 11 3.4.4 American Society for Testing and Materials ...... 12 3.4.5 DOE Action Levels ...... 12 3.4.6 Threshold Quantities for DOE Category 2 Nuclear Facilities ...... 13 3.4.7 Comparison of Bounding Limits with Regulatory Criteria ...... 14 3.5IMPORTANT INFORMATION GAPS ...... 14

4. CHARACTERIZATION INFORMATION NEEDED BY VENDORS ...... 15 4.1 VENDORS’ DESIGN REQUIREMENTS ...... 15 4.2CHARACTERIZATION INFORMATION NEEDED...... 15 4.3 POTENTIAL COST CONSEQUENCE FOR ENCOUNTERING CONTAMINANT CONCENTRATIONS HIGHER THAN A REPORTED BOUNDING VALUE ...... 16 4.4 OTHER CHARACTERISTICS THAT SHOULD BE INCLUDED IN CYLINDER CHARACTERIZATION...... 18 4.4.1 Radiochemical Impurities (Other than Np, Pu, Am, and Tc) ...... 18 4.4.2 Impurities with the Potential to Affect Conversion Processes ...... 18 4.4.3 Cylinder Handling Characteristics ...... 19 4.4.4 Additional Useful Information ...... 20

5. METHODOLOGY FOR ANALYSIS OF CYLINDER CONTENTS ...... 20

5.1 UNFILTERED LIQUID UF6 SAMPLES ...... 20 5.2 FILTERED LIQUID UF6 SAMPLES...... 21 5.3GENERATION OF HEELS BY EMPTYING CYLINDERS...... 21 5.4 HEELS ANALYSIS FROM CYLINDER WASHING ...... 22 5.5 NONDESTRUCTIVE ANALYSIS ...... 22

iii 5.6SOLID SAMPLE RETRIEVAL BY A CORING DRILL...... 22 5.7CONCLUSIONS...... 23

6. RECOMMENDED CHARACTERIZATION STRATEGY ...... 23

7. REFERENCES...... 24

APPENDIXES

Appendix A. Task Statement for Developing a Characterization Strategy...... A-1 Appendix B. Statistical Analysis of Cylinder Sampling...... B-1 Appendix C. Upper Bound Estimates of Pu, Np, and Tc Concentrations

in DUF6 Cylinders ...... C-1 Appendix D. Other Characterization Information...... D-1

Appendix E. Options for Sampling and Analysis of DUF6 Cylinder Contents...... E-1 Appendix F. Identification and Selection of Populations of DUF6 Cylinders for Sampling...... F-1

iv ACRONYMS AND ABBREVIATED FORMS

ALI annual limit on intake ANL Argonnne National Laboratory ANSI American National Standards Institute ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials B&PV Boiler and Pressure Vessel (Code) CFR Code of Federal Regulations DAC derived air concentration DOE U.S. Department of Energy DOT U.S, Department of Transportation

DUF6 depleted EM Office of Environmental Management (DOE) ETTP East Tennessee Technology Park GDP plant IAEA International Atomic Energy Agency LLNL Lawrence Livermore National Laboratory LMES Lockheed Martin Energy Systems, Inc. MT metric tons NBIC National Board Inspection Code NDA nondestructive analysis NRC U.S. Nuclear Regulatory Commission ORGD