Ivan P. Salati de Almeida Director of Radiation Protection and Nuclear Safety Brazilian Nuclear Energy National Commission- CNEN September 2012 Small Scale Post-Accident Remediation Senior’s Regulator Meeting Session II - Specific Challenges in Implementing Remediation

Brasilia Goiania The accident of Goiania - Brazil R.Janeiro S.Paulo Goiania-Brasilia=173 km Goiania-S.Paulo=937 km Goiania-R.Janeiro=810 km Distances

Location City: Goiania (Capital of the State of Goias) Population: ~ inhabitants (at the time of the accident) Teletherapy equipment with Cs-137 source Day of the accident: September 13 th,1987

Impacted area

CS-137 source characteristics Source activity (Sept/87): 1375 Ci (50.9 TBq) Chemical composition: caesium chloride (CsCl) Physical condition: compacted powder Mass CsCl: 93 g Mass Cs-137: 19.3 g

Chronology September 10 th to 13 th,1987: part of a teletherapy equipment with a caesium-137 source was removed from an abandoned building and opened, breaching the caesium capsule. September 13 th to 28 th : the Cs-137 was distributed to other people and was spread through other places in the city. Several people were hospitalized with symptoms of high doses irradiation. September 28 th to 29 th : the accident was confirmed by a medical physicist and first actions were taken by local authorities. September 29 th to 30 th : CNEN was notified and sent experts to Goiania.

Main issues to be dealt with in the accident People monitoring and assessment of environmental contamination Medical care for victims (irradiated and contaminated) Re-establishment of the source control Decontamination of the places Interim storage for the waste generated Definition and construction of a repository

Monitoring people Olympic Stadium (112,800 persons monitored)

Data from the accident l Monitored persons = 112,800 l Contaminated persons =271 clothes and shoes = 120 body contamination= 151 l People with deterministic hazards=28 l Victims hospitalized=20 l Syndrome of acute radiation =8 l Hazards in bone marrow =4 l Deaths = 4

Main contamination foci

Data from the accident l 7 main contaminated places l 42 additional contaminated places l 85 contaminated houses; 7 demolished l 50 vehicles decontaminated l Aerial survey with helicopter equipped with radiation detector (67 km 2 monitored) l Terrestrial survey with a car equipped with radiation detector

Data from the accident l Equipment: 55 dose rate meters, 23 contamination monitors 450 dosimetric pens l Professionals involved: 250 technical staff 300 support staff l Time First period: September 29 th to December 24 th 1987 Second period: January to end of March 1988

The main piece of the source 0.4 Sv/h at 1m (~120 Ci) Emergency shielding

Site isolated for decontamination Decontamination work

n 57th Street n Place where the source was opened Decontamination work

n House and land contaminated n Dose rate 1,1 Gy/h at 1m Decontamination work

equipment head Decontamination work

n Assignment of contaminated areas n Criteria (0.5  Sv/h) Decontamination work

–5 mSv first year –1 mSv/y dose for the whole life –Critical path for exposition: Gama exposition inside home Gama exposition outside home Internal dose due to inalation and ingestion of fruits, vegetables, domestic animals Criteria for decontamination

Remediation actions Part of the soil was removed and covered with concrete Part of the soil was removed and substituted with non contaminated soil Contaminated trees were cut down

Waste resulted from the accident 3,500 m 3 (6,000 Ton.) 1,343 metallic boxes 4,223 drums (200 liter each) 10 maritime containers 8 Concrete cylinders VBA type

Interim storage of waste

Final Repository

Deposit 1 (common waste < 90 years) Store about 40% of waste (very low activity). Deposit 2 ( 300 years) Dimensions: –Wall thickness: 25 cm –Basis surface distance from the soil level: 80 cm –Length: 54 m –Width: 14 m –Height: 4 m Final Repository

n Regional Center for Nuclear Sciences Information Building Final Repository

The end Thank you