PUBLIC HEALTH ASSESSMENT

Community Exposures to the 1965 and 1970 Accidental Tritium Releases

LAWRENCE LIVERMORE NATIONAL LABORATORY, MAIN SITE (USDOE)
LIVERMORE, ALAMEDA COUNTY, CALIFORNIA
EPA FACILITY ID: CA2890012584

July 11, 2003

Prepared by:

Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

SUMMARY

SECTION 1: INTRODUCTION AND ENVIRONMENTAL PATHWAYS

Site Description and History
Exposure Pathways
Estimated Population of Affected Areas

SECTION 2: COMMUNITY HEALTH CONCERNS ON THE ACCIDENTAL TRITIUM RELEASES

SECTION 3: EXPOSURE ASSESSMENT AND DOSE ESTIMATION

Dispersion of the HT Releases
Evaluation of the 1965 Accidental Release
Inhalation Exposure
Ingestion Exposure
Total Tritium Doses and Uncertainties in Dose Modeling Procedures

SECTION 4: PUBLIC HEALTH IMPLICATIONS OF ESTIMATED TRITIUM DOSES

Toxicology of Tritium
Special Consideration of Women and Children
Tritium Doses of Public Health Concern
Health Outcome Data Evaluation

SECTION 5: CONCLUSIONS AND RECOMMENDATIONS

REFERENCES

PREPARERS OF REPORT

Reviewers of Report
Regional Representative

APPENDIX 1: COMMENTS ON THE PUBLIC RELEASE VERSION OF PHA

APPENDIX 2: DESCRIPTION OF RASCAL AIR DISPERSION MODEL AND ASSUMPTIONS

APPENDIX 3: DESCRIPTION OF THE INDUSTRIAL SOURCE COMPLEX SHORT-TERM (ISCST3) AIR DISPERSION MODEL AND ASSUMPTIONS

APPENDIX 4: DESCRIPTION AND ASSUMPTIONS OF MONTE CARLO ANALYSIS OF TRITIUM DOSE ESTIMATES

APPENDIX 5: ATSDR GLOSSARY OF TERMS

LIST OF TABLES

Table 1. Estimated soil HTO emission rates (Ci/second-m²⁾ for the 1965 and 1970 releases at the initial maximum rates.

Table 2. 30-minute HT inhalation doses and 12-day HTO inhalation doses (in millirem) at various distances from tritium source.

Table 3. Cumulative annual tritium doses to maximally exposed individuals following either the 1965 or 1970 accidental tritium releases from the LLNL tritium facility.

Table A-1. Maximum instantaneous HT concentrations during plume passage (08/06/70).

Table A-2. Cumulative HT concentrations at various downwind distances and directions after plume passage (08/08/70; from RASCAL).

Table A-3. Cumulative HT concentrations at various downwind distances and directions after plume passage (01/21/65; from RASCAL).

Table A-4. Case Summary of RASCAL Analysis for 1970 LLNL Release.

Table A-5. Case Summary of RASCAL Analysis for 1965 LLNL Release.

Table A-6. Maximum 1 hour HTO concentrations in air (1 m above ground level) estimated using hourly August weather observations (at the centerline of the plume (20E from tritium facility).

LIST OF FIGURES

Figure 1. Map of the LLNL facility showing the area of potential exposures from the 1965 and 1970 tritium releases.

Figure 2. Conceptual exposure pathway and exposure factors related to short-term human inhalation and ingestion of tritium from the 1965 and 1970 LLNL HT releases.

Figure 3. Conceptual diagram of tritium dispersion and transformation based on airborne release of tritium gas (HT) and subsequent microbial transformation into tritiated atmospheric and soil moisture (HTO).

Figure 4A. Estimated HTO emission rate at 1.0 mile from the LLNL tritium facility.

Figure 4B. Estimated lognormal probability distribution of HTO air concentrations at 1 mile from tritium facility.

Figure 5. Estimated daily HTO child inhalation dose at 1 mile from the LLNL tritium facility (1970 or 0.5 mile in 1965).

Figure 6. Probability distribution of 12-day child ingestion doses following either the 1965 or 1970 LLNL accidental tritium releases.

Figure 7. Estimated total tritium dose to a child from the August 6, 1970 tritium release.

Figure A-1. HTO Air Concentrations and Percent Soil HTO after the 1970 Release Event.

Figure A-2. Isocontours of the highest 12-hour HTO Air Concentrations at 1 m above ground.

LIST OF APPENDICES

Appendix 1. Peer Reviewer and Other Comments to Public Release Version of PHA

Appendix 2. Description of RASCAL Air Dispersion Model and Assumptions

Appendix 3. Description of the Industrial Source Complex (Short-term; ISCST3) Air Dispersion Model and Assumptions

Appendix 4. Description and Assumptions of Monte Carlo Analysis of Tritium Dose Estimates

Appendix 5. ATSDR Glossary of Terms

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