1 / 27

Funeral Home Decommissioning

Funeral Home Decommissioning. 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. Prostate Treatment Process.

ginger
Download Presentation

Funeral Home Decommissioning

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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?

More Related