management of the radioactive wastes generated in the
TRANSCRIPT
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Management of the Radioactive Wastes Generated in the Response
to the Radiological Accident in Goiânia, Brazil
Roberto Vicente Instituto de Pesquisas Energéticas e Nucleares (IPEN)
Comissão Nacional de Energia Nuclear
February 11, 2013
This presentation is based mainly on the 1988 IAEA’s Report “The Radiological Accident in
Goiânia” – a detailed account of the accident, its causes, consequences and response, on
other published material, and on my personal experience as member of the response team.
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Climate: temperature: 18 – 30 C; average rainfall: 1576 mm
1.33 million inhabitants and 2.17 million inhabitants in the metropolitan
area (~1,000,000 in 1987, at the time of the accident)
1st most socially unequal capital city in Brazil and 10th in the World
Per capita income: US$ 7,500 (2010) (Brazil: US$11,800)
Present day view of Goiânia
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Background Information
National Nuclear Energy Commission
•Brazilian Regulatory Body
•Government Policy Advisor on Nuclear Issues
•Executive Agency of R & D on Nuclear Applications
Founded: 1956
Headquarters: Rio de Janeiro
Subordinated to Ministry of Science and Technology
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Regulatory role Executive role
Responsibilities
Initial storage: licensees
Interim storage
Final disposal CNEN
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Indústrias Nucleares do Brasil
The public company responsible for exercising
the State monopoly over nuclear materials and
that process uranium, from mine to nuclear fuel
fabrication.
A public company in charge of building and operating
nuclear power plants, presently produces about 3 %
of the Brazilian eletricity supply with Angra units I and
II (600 MWe Westinghose PWR + 1300 MWe KWU
PWR), and constructing unit III (1300 MWe)
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Final Disposal Facility of “Goiânia
Accident” Wastes – Abadia de Goiás
Central-West Regional Center of
Nuclear Science - Goiânia
Northeast Regional Center of
Nuclear Science - Recife
Uranium Mine - Caitité
Nuclear Technology Development
Center - Belo Horizonte
Uranium Enrichment and Fuel
Fabrication Plant - Rezende
Nuclear Engineering Institute
Rad.Protect.& Dosimetry Institute
CNEN Headquarters - Rio de Janeiro
Nuclear Power Plant - Angra
Nuclear and Energy Research
Institute – São Paulo
Navy Research Center - Sorocaba
Research Reactor
o - operational; p - planned
NPP
p
o
o
o
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Roots of the accident
Instituto Goiano de Radioterapia ( IGR), a private institute
owned by a medical partnership, was licensed in 1971 to
import the Caesium-137 teletherapy unit;
In 1985, ceased operating in the former premises and a
new partnership took over other premises;
Ownership of the content of the clinic was disputed and
the equipment was left in place.
The circumstances that led to the abandonment of the
machine had not been completely clarified. Every one
involved tried to evade responsibility and some years
after the accident all were still responding to lawsuits.
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At the time of the accident, the derelict Radiotherapy
Clinic from which the teletherapy equipment was
taken, was in the area of a re-urbanization project.
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Chronology of the accident
13 Sept. – Two men take the rotating assembly from the
clinic, transport it in a wheelbarrow (~ 0.5 km) to the house
of one of them and leave it in the courtyard.
18 Sept. – The source wheel is separated from rotating
shutter, the window of the source is punctured with a
screwdriver and some of the source scooped out. The
pieces of the assembly are sold to junkyard 1 where a blue
glow is noticed, later that evening.
18 – 26 Sept. – Fragments of the source are distributed to
many individuals. Parts of the assembly are taken to
junkyards 2 and 3.
26 Sept. – The shielding container (300 kg) is also removed
from the clinic and taken to the junkyard 2.
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Chronology of the accident
28 Sept. – Convinced that the glowing powder was
causing illness to her family, junkyard manager wife
collected the remnants of the rotating assembly in a bag
and took it by bus to a Health Surveillance Office.
29 Sept. – The material is recognized as radioactive, the
source is left over a chair in a courtyard of the Health
Surveillance Office and the response is initiated.
29 Sept – 02 Oct – Emergency phase
Early Oct. – 23 Dec. – First phase of decontamination.
Jan 1988 – March 1988 – Second phase and fine
cleaning decontamination work.
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Other cities with contaminated sites
Anápolis - Go
Aparecida de Goiânia – Go
Inhumas – Go
Araras – SP
São Carlos – SP
Osasco – SP
São Paulo - SP
Early response: health care of ill people
49 people were admitted to hospital
22 needed intensive medical care (10 in critical condition)
14 transferred to specialized care in Rio de Janeiro
4 of whom died in late October, including a 6 year old girl (LN)
Estimated doses incurred : 4.5 Gy to 7 Gy
Early response: radiation screening of population
112,000 people were scanned for radiation
129 identified with significant internal/external contamination.
120 found with significant external contamination only.
Early response: Oct. 1 – 3
With a crane, concrete pipes were put around the chair
and used as a mould for shielding with pumped concrete
Early response:
Establish radiation protection checkpoints in Hospitals
Note: Skin contact dose rate in one of the patients: 15 mSv/h
Early response: Radiological survey of the city
Aerial survey with a portable NaI(Tl) spectrometer
mounted in a helicopter on 7-8 Oct., covering about 67
km2 and later complemented with a survey by car
- 42 sites of contamination found in Goiânia
Early response:
Each contaminated area was fenced and radiation
protection checkpoints were built in each site
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Radioactive Waste Management
Front line issues
Establish a strategy to remove contaminated material
Decide on criteria for screening ‘waste-not waste’
Find a suitable place to store the wastes
Estimate amount of waste that would be generated
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Junkyard II - Widespread contamination
Up to ~ 2 Sv/h in the doorstep of ‘LN’ house
Radioactive Waste Management
Rua 57 – The most contaminated site Dose rate: 1.1 Sv/h – 1 m above contaminated ground
The same steps were followed in all other sites
Paper recycling collection center – origin of most
contaminated material brought to cities in São Paulo.
Transport of the waste packages starts mid-November
The last job of each work shift: to load the packages in
trucks and transport them in a convoy to the storage site.
Meanwhile, contaminated paper bales transported to São Paulo before
the accident was recognized, were collected and stored at IPEN and
packaged in 50 boxes brought from Goiânia in August 1988.
The metal scrap collected in São Paulo as well wastes generated in the treatment
of the victims were packaged in drums and are also now stored at IPEN.
Final disposal of the radioactive wastes
Two repositories were built: one for the packages of
category I and another for the more active wastes
Construction of the disposal facility for Cat. I wastes
Construction of the disposal facility for Cat. II-V wastes
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The remnants of the source and several drums
damaged by corrosion after 6 years stored over
the platforms, were repacked before disposal.
Final disposal structures
Cat. 1 wastes in the foreground
Cat. 2 – 5 wastes in the background
Note the skyline of ‘Abadia de Goiás’ on the right
In Dec. 1995, Abadia de Goiás, a former district of
Goiânia, was raised to the category of municipality,
and proudly sports the radiation symbol in its flag.
Problems/difficulties that the response team faced in the emergency phase
1. Decide what was, what was not radioactive waste
Comment: Initially, it was proposed to collect contaminated material in drums,
measure the dose rates at contact and at 1 m from the surface of the package,
estimate the activity concentration and decide on the classification of the material.
The threshold value of transport regulation (75 Bq/g) or even the derived
concentration limit for ingestion of Cs-137 in milk powder were considered as
criterion. Prevailed the idea of collecting everything that deflected the scale of the
detectors.
2. Implement procedures for screening
Comment: In most sites the ambient dose rate prevented from taking
measurements of specific materials. Sampling of materials for characterizing
contamination was useless because of the inhomogeneity of the contamination.
3. Waste treatment
Comment: As the amount of contaminated paper was large, incineration as a
means of reducing the volume was cogitated but the idea was abandoned
because of the high costs and the low impact on the total waste volume to be
disposed of. Decontamination of soil was attempt but results were not good.
Biological materials were stabilized by addition of lime. Excreta of patients and
other wastes from health care of victims were immobilized in cement.
Problems/difficulties that the response team faced in the emergency phase
4. Estimate the amount of waste in order to select or design a temporary
storage
Comment: Any reasonable estimate seemed impossible in view of the chaotic
appearance of some sites and the uncertainty on the extent of contamination.
5. Find a suitable storage site
Comment: The first site visited by the team had the next morning every access
closed by barricades.
6. Find materials and equipment, for instance shielded containers,
manipulator arm, in the emergency phase
Comment: Some improvisation was necessary in early action.
7. Prevent people from furtively entering the contaminated sites
Comment: Although fenced, posted and guarded by police force, the sites were
systematically invaded by locals to recover property, feed pets etc.
Problems/difficulties that the response team faced in the emergency phase
8. Dogs, cats, pigeons, rats and other animals walked and fed in heavily
contaminated ground
Comment: In the beginning it seemed that nothing could be done to prevent this.
Later, captured animals were sacrificed and then packaged in plastic bags with
lime and cement powder, before being placed in drums as radioactive waste.
9. Salvage of some pieces of property was necessary
Comment: In some cases, the team made efforts to retrieve and decontaminate
photographs, jewelry, documents, etc.
10. Detailed account of the work done each day
Comment: In the first days of the response, the team was so committed to trying
to solve the problems that ended up forgetting to leave written records.
Problems/difficulties that the response team faced in the emergency phase
11. Indemnification of property collected as radioactive waste
Comment: Many people involved directly or not in the accident have lost all their
possessions and were indemnified by the government despite the lack of legal
and regulatory basis.
12. Stress and anxiety
Comment: At last once, the team received death threats from the owners while
initiating the demolition of their houses.
13. Work under bad weather conditions
Comment: Most of the time, the decontamination work was done under adverse
weather conditions – heavy or copious rain and high temperature.
14. Harassment by the press, opposition discourse by NGO’s, mistrust of
site neighbors