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

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

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

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

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

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

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

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

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

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

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

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’)

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

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

Location

Total Activity

(dpm/100cm2)

Removable Activity

(dpm/100cm2) Remediation Method

Office Floor 5K 0.8K Wet Wipe

Prep Table 13K 1.4K Wet Wipe

Process Room Floor312K 5.6K Scabble, Vacuum

Process Room

Pulverizer265K 10K Vacuum,

Scrubbed, scoured and wiped

Retort Room Floor 1.4M 60K Vacuum,

Scrubbed, scoured and wiped

Inside RetortOff Scale

1 mR/hr

24K Vacuumed, dose rate reduced dramatically

Hammered

Removed 2.5” to 5” of floor liner

Process Room

Exhaust Duct3.5K 112 Wet Wipe

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

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

Questions?