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Funeral Home Decommissioning

Funeral Home Decommissioning

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Funeral Home Decommissioning

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  1. Funeral Home Decommissioning

  2. Overview • Prostate cancer patient with I-125 seed implants • Cremated at a funeral home • Resulted in contamination of retort, processing equipment and surrounding rooms • Agreement State required decontamination to very restrictive limits

  3. Prostate Treatment Process • Part 1 – implants • 63 sources (seeds) • 0.250 mCi /seed • Total: 15.8 mCi • Written discharge instructions • “The Radiation Safety Officer should be notified if the patient is hospitalized, or if death should occur.” • Part 2 – external beam treatments

  4. Cremation Process • Temperature: 1400-2100 F • Duration: 2-3 hours • Combustion Air Flow: 2000 – 2500 cfm • Cooling Period: 1 hour at 500 - 1000 cfm • Remains: 3-9 lbs (bone fragments) • Soft tissue vaporized • Bone fragments normally pulverized after cremation. • Source: Cremation Association of North America

  5. Average Prostate Implant • Activity • 35 mCi I-125 • Dose Rates • 0.14 mR/hr @ 1 meter from patient • 1.6 mR/hr on contact patient’s abdomen • Source - Journal of Applied Clinical Medical Physics

  6. Historical Events • Two instances in NRC jurisdiction • 9.8 mCi – cremated with NRC permission • 2 mR/hr on contact w/ plastic bag of remains • Bkg after placing bag in metal urn • 12 mCi – cremated with NRC permission • No data regarding dose rates

  7. Chronology 1 • Day (-14): Seeds implanted • Day (-3): Patient died • Day 0: Clinic notified of death, patient cremated, initial characterization, clinic RSO helps funeral home complete cremation procedures • Day 1: State regulator notified, remains transferred, facility characterized • Day 2: State inspection and survey • Day 6: Follow up surveys – State inspector and clinic RSO • Day 7: Chase notified and provides decommissioning proposal and prepares to mobilize

  8. Chronology 2 • Day 6 – Day 73: Funeral Home and State negotiate course of action. Options: • Shutdown and decay • Decommission – refractory was scheduled for relining regardless of incident • Day 73: Funeral Home decides to proceed with decommissioning • Day 73 – Day 103: State decides release criteria • Day 103 – Day 107: On-site work • Day 110: Final Status Report submitted to State • Day 131: State confirmatory surveys complete • Day 133: Facility released for unrestricted use

  9. Initial Response • Therapy Clinic RSO responds • Conditions • Implant patient ashes in pulverizer • 2nd cremated body (ashes) inside retort • 3rd body in refrigerator ready to cremate • Dose Rates w/GM detector • 100 mr/hr inside retort • 10 mr/hr external to pulverizer • 1 mr/hr at retort door

  10. Surveys of Remains • Patient remains in plastic bag and plastic transport box – 10 mr/hr contact • Remains buried • Remains of 2nd person in plastic bag and plastic transport box – 0.1 mr/hr contact • Remains returned to family • Activity homogenously dispersed in ashes

  11. Contaminated Items • Some items taken to Clinic for DIS • Broom head, brushes, whisk broom, dust pan, leather gloves • Clinic makes a commitment to accept all waste from remediation for DIS • State approves DIS at clinic

  12. Operator Dose Assessment • Clinic RSO performed dose assessment • External dose to operator estimated by dose rate measurements and time-motion study • Measurements corrected for energy differences between Cs-137 (cal source) and I-125 • Thyroid scan conducted at local hospital – don’t know results • Total dose was 12 mrem to hand and 0.6 mrem TEDE

  13. Facility Layout

  14. Impacted Areas • Retort and Exhaust • Retort (3’ x 8’) • No filters or pollution control equipment • Crematory Room(8’ x 29’) • Processing Room (9’ x 10’) (a walled-off section of the Crematory Room) • Office (15’ x 15’)

  15. Retort

  16. Retort Exhaust Stack

  17. Processing Room

  18. Office

  19. State Release Criteria • State regulations are 25 mrem/yr w/ALARA • State would not consider dose modeling or application of NRC default screening values • NRC DSV for I-125 is 690,000 dpm/100cm2 • Site-Specific Criteria • 20 dpm/100cm2 removable based on RG 1.86 • State not really concerned with total contamination or dose rates • Chase implemented criteria of detectability (~1000 dpm/100cm2) as a goal for identifying areas for remediation to mitigate risk of exceeding removable contamination limits

  20. FSS Instrumentation • Direct Measurements • Field Instrument for Detection of Low Energy Radiation (FIDLER) • Bicron G5 and LMI 2221 • Thin Nal(TI) Scintillation Crystal (5” Dia x 0.063” thick) • Thin Window: Beryllium, (0.010” thick) • Energy window set at 20-40 kev to capture I-125 emission for survey –AND - to capture I-129 emissions for calibration and efficiency determination (~22% efficiency, ~ 700 cpm bkg) • Removable Measurements • Packard Tri-carb 2800 liquid scintillation counter • Single channel 0-80 kev, 78% efficiency

  21. Bicron G5 FIDLER

  22. Characterization and Remediation

  23. Retort Post-Remediation

  24. Final Status Survey

  25. Final Status Survey Results • All smears (except one) < 20 dpm/100cm2, • Direct Measurements up to 1400 dpm/100cm2 • NORM in refractory materials • 112 dpm/100cm2 inside exhaust duct – performed dose assessment to leave in place • Not accessible for occupancy • <<<<<< DSV • Short half-life • Ridiculous to even think about remediating • State accepted

  26. Key Points • State regulator - conservative release criteria • No signs of the SS seed capsules • Radioactivity attached to ashes – where there was no ash, there was no radioactivity • Significant mixing of ashes between cremations • If you get cremated, you will have company for eternity • Two cases in NRC jurisdiction – NRC does not view as a concern

  27. Questions?