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State Nuclear Regulatory Committee of Ukraine
State Nuclear Regulatory Inspectorate of Ukraine
APPLICATION OF THE
OPTIMIZATION PRINCIPLE
IN POST-ACCIDENT COUNTER-MEASURES
IMPLEMENTATION
(POST-CHERNOBYL (EXPERIENCE)
Olena Mykolaichuk
State Nuclear Regulatory Inspectorate of Ukraine, Chairperson
Valeriy Kashparov
Ukrainian Scientific Institute of Agriculture Radiology
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State
Nuclear Regulatory
Committee of Ukraine
Post-Chernobyl
counter-measures
• After Chernobyl accident a
wide range of urgent immediate
and long-term protective
measures (counter-measures)
was applied
• The world community recognized
that the application of countermeasures/remediation after the
Chernobyl accident had made
possible to reduce the public
exposure doses more than twice
• The Chernobyl experience
became the basis for the national
standards and Chernobyl Forum
recommended to apply it
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State NuclearNational
Regulatorystandards
Committee of Ukraine
and post-Chernobyl experience
• While planning and application of immediate and longterm counter-measures/remediation the three main
radiological protection principles shall be considered :
– Justification
– Not exceeding
– Optimization
• Optimization is especially important for the main
immediate counter-measures that despite high avert
dose are expensive, need a lot of organizational
resources and course big discomfort, losses and
inconvenience for public
• Basis for immediate counter measures optimization
should be prepared in advance to provide quick
decisions
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
National
State Nuclear
Regulatorystandards
Committee of Ukraine
• Justification of counter-measure shall be made on the basis
of the assessment and comparison of social and economical
losses, damages and inconvenience, coursed by counter
measure and the level of avert dose due to counter measure
application
• Appling “not exceeding” principle counter-measure could be:
- unconditionally justified
- justified
- not justified
• Radiological criteria for justification are fixed in national
radiation safety standard (NRBU-97)
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State NuclearNational
Regulatorystandards
Committee of Ukraine
Application of Optimization
• Between the lower justification limit and unconditionally
justified levels the decision of undertaking of countermeasure requires the procedure of optimisation.
• Though all these countermeasures located within
specified area are justified, optimization procedure prior
their undertaking (or not undertaking) is important and
absolutely necessary step that takes into account of all
the damage kinds due to countermeasure undertaking.
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
Example
State Nuclear Regulatory Committee of Ukraine
JUSTIFICATION FOR IMMEDIATE COUNTER-MEASURES
(NRBU-97)
Avert dose during the first 2 post-accident weeks
Counter-measure
Lower justification limits
mSv
Unconditionally justified levels
mGy
mSv
For whole For thyroid gland For skin
body
mGy
For whole
body
For thyroid
gland
For skin
Sheltering
5
50
100
50
300
500
Evacuation
50
300
500
500
1000
3000
Iodine prophylactics
Children
-
501
-
-
2001
-
-
2001
-
-
5001
-
1
20
50
10
100
300
2
100
200
20
300
1000
Adults
Restriction of staying at
open air
Children
Adults
1–
Dose expected under internal exposure by iodine radioisotopes that enter organism during
the 1st two weeks since the accident beginning
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear
Regulatory
of Ukraine
Application
ofCommittee
Optimization
•
•
•
•
When counter- measures application is justified the
optimization is performed to ensure maximum level of their
effectiveness with account to:
Radiological aspects (the avert dose, reduction of
contamination level of territories, environment, foodstuff
etc.)
Economical aspects (scopes of funding, equipment and
technologies availability, etc.)
Socio-psychological aspects (acceptability of countermeasures, impact on public opinion, cultural aspects etc.)
Political aspects (political decisions, international
situation, ets.)
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State
Nuclear Regulatory
Committee of Ukraine
Optimization
by radiological
factor
• Currently in new BSS for existing exposure, each Member
State could set its own acceptable reference level of
exposure of representative individual in the frame of 1 to 20
mSv/year above which the long-term counter-measures
application should be optimized
• In Ukraine this level is considered as 1 mSv/year
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclearby
Regulatory
Committee of Ukrainefactors
Optimization
socio-psychological
• Social, psychological and political factors could overweight
the economical and radiological ones
• Optimization by socio-psychological factors can be done by
means of public involvement into decision making, especially
in long-term remediation counter-measures application
Examples
• After Chernobyl accident the compensatory payment was
established in contaminated regions. Due to socio-political
reasons the compensatory payment can’t be cancelled
although the radiological situation have changed
• One year after Fukusima accident Japan established the
most severe in the world permissible levels for foodstuff
radionuclide concentration due to socio-psychological factor.
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
Inadequate
risk
perception
State Nuclear
Regulatory
Committee
of Ukraine
• Lack of information in the initial
post-accident period about
impact of water pathway into
overall dose
• Inadequate “water” risk
perception by Public and
Decision makers and
overestimation of risk
• Not optimized decision for large
number of inadequate water
protection measures carried out
during initial post-accidental
period (river canal and run-off
regulation by dams on the
contaminated catchments).
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State NuclearOptimization
Regulatory Committee
of Ukraine
Example.
in Restrictions
of Foodstuff Consumption
• Restrictions of foodstuff consumption shall be the
subject for optimization by three main factors:
– Averted Internal dose
– Necessity to support profitable agricultural
production
– Negative health effects as result of restriction
in some food products consumption
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear
Regulatory Committee
of Ukraine
Example.
Optimization
in
Restrictions of Foodstuff Consumption
• As a result of optimization permissible levels
for foodstuff went down as time passed after
the accident
• In Ukraine permissible levels for foodstuff were
revised twice in 1986 and than in 1987, 1988
and 1991
• Actual levels are lower than EC import levels
and reference levels in Codex Alimentaris
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear Regulatory Committee of Ukraine
Example.
Optimization for Urban Decontamination
• Optimization factors: type of fall out, averted dose and cost
• Optimization conclusions were done for urban surfaces
decontamination in the case of the dry fallout:
– Streets cleaning, trees and bushes removal, green
places ploughing-up – optimized
– Roofs cleaning – not optimized by cost though high
averted doses
– Walls cleaning - not optimized because of low averted
doses
• 25% - maximum reduction of dose due to urban
decontamination. Not overall decontamination reduced
effectiveness
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear Regulatory Committee of Ukraine
Example.
Optimization for Meat, Soil and Forests”
• Meat
– Butchering with following meat storage and disposal was done
without optimization that lead to significant exceeding of damage
over benefit
• Moving of the upper layer of the soil proved to be not
optimized counter measure due to:
– high cost of work
– radioactive waste disposal costs
• As a result of optimization process “ for forests” following
countermeasures proved to be effective for forests:
– Restrictions of: access, forest products gathering, use of firewood
and ashes
– Forest fire prevention
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear Regulatory Committee of Ukraine
Example.
Optimization “for Water Protection”
Not optimized
Initial post-accident measures to protect water systems
from radionuclide transfer from contaminated soil can not
be optimized due to high costs and workers high doses
Optimized
In the later phase of the remediation:
• wide scale multi-disciplinary studies
• model simulation
created a basis for optimization water remedial actions
and identified the only limited set of effective actions,
which sufficiently reduced secondary long-term significant
contamination of the aquatic system: dyke the most heavy
contaminated radioactive hot spot in vicinity of ChNPP site.
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear Regulatory Committee of Ukraine
1986
90Sr
1993
1999
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
Remediation
Optimization
Prerequisites
State Nuclear Regulatory
Committee
of Ukraine
and Factors
• Prerequisites
– Regulatory framework with established radiological
criteria
– Emergency preparedness infrastructure than includes:
• Expert groups (national and international)
• Tools: handbooks of parameters’ values, codes,
guides, monitoring system
• Knowledgeable decision makers
• Communication with public
• Factors: Source term; Fallout details; Environmental
conditions (landscape, soil types, vegetation, land use,
hydrology etc); Social conditions
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear
Regulatory
Committee
of Ukraine
Immediate
and
Long-term
Countermeasures
Optimization Preparedness
• Basis for immediate counter measures optimization
should be prepared in advance to provide quick expert
decisions
• For long-term remediation measures should be
supported by system for remediation strategy
optimization
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear Regulatory
Committee of Ukraine
ReSCA
• In the frame of IAEA regional projects RER/9/074,
RER/3/004 and RER/9/123 the support system for
making decisions on remediation of radioactive
contaminated areas after Chernobyl accident - ReSCA
has been established
• ReSCA considers the factors important for optimization of
the appropriate counter-measures application at the
territories affected by the Chernobyl accident aiming to:
- minimize the costs of avert dose of the public
- decrease the exposure dose of a representative individual
below the accepted reference level (according to the latest
BSS approach)
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear Regulatory
Committee of Ukraine
ReSCA
• Optimization of remediation strategy requires consideration
of a wide range of factors
- technical (e.g. effectiveness, feasibility)
- economical (cost, resources)
- environmental (coefficients of improvement)
- social (acceptability, opportunities for self help in rural
communities)
• In Ukraine, the implementation of the optimized remediation
strategy will reduce the annual doses in the affected
settlements below 1 mSv with overall costs less than 1 M€.
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
StateReSCA
Nuclear calculations
Regulatory Committee
Ukraine
results.ofReduction
of
settlements where dose > 1 mSv/year
after the application of
countermeasures in 2011
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear
Regulatory
Committee
of Ukraine
ReSCA
practical
test
• ReSCA calculations for 14 Ukrainian settlements
• Calculations proved that most effective countermeasures
by all factors optimization (coefficient of improvement,
public acceptability, stability, cost etc) will be ferrocyanide
blue application for cattle feeding and radical improvement
of meadows
• 3 test settlement with optimized counter-measures
applied in practice
• Annual dose reduced from 1.6 to 0.6 mSv due to milk
contamination reduction from 900 kBq/kg to 150 kBq/kg
• Cost was 5 kEuro per 1 manSv
• Remediation measures for meat, potatoes, drinking water,
inhalation, external exposure proved to be not optimized.
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
State Nuclear Regulatory Committee of Ukraine
Reduction factors in ReSCA
Exposure pathway
Internal
exposur
e
Remedial actions
RI
SI
FA
FP
MF
IM
RS
Milk
4.00
1.50
3.00
-
-
-
-
Beef
4.00
1.50
2.00
-
-
-
-
Pork
-
-
-
3.00
-
-
-
Potatoes
-
-
-
-
2.00
-
-
Mushrooms -
-
-
-
-
1.50
-
-
-
-
-
-
1.50
External exposure
-
Counter-measures:
• RI - Radical Improvement
• SI - Surface Improvement
• FA - Ferrocyn Application
• FP
- clean Feed for Pigs
• MF - Mineral Fertilizers for potato
• IM - Information on Mushrooms
• RS - Removal of Soil in the
settlement area
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
Optimization
factors
in ReSCA
State Nuclear Regulatory
Committee
of Ukraine
Characteristic
RI
SI
Stability (y)
4.00 4.00 1.00 1.00 1.00 2.00 27.0
Cost (euro)
350
Degree of
acceptability
1.00 1.00 0.75 0.60 1.00 0.50 0.10
300
Counter-measure:
• RI - Radical Improvement
• SI - Surface Improvement
• FA - Ferrocyn Application
FA
30
FP
6
MF
1
IM
3
RS
325
• FP
- clean Feed for Pigs
• MF - Mineral Fertilizers for potato
• IM - Information on Mushrooms
• RS - Removal of Soil in the
settlement area
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
Conclusions
State Nuclear Regulatory Committee of Ukraine
• Regulations should require that countermeasures and
remediation must be based on a cost-risk analyses that
directly connects the main physical and chemical
processes to environment (ecosystem) or human heath
risks and costs
• National system for optimization preparedness as part of
emergency preparedness should be created. This system
as minimum should include regulations, experts, tools,
knowledgeable decision makers and communication with
public
• Systems to Support Remediation Strategies establishment
is useful with customization to accident specific features
• As residual radioactive pollution still exists, and our
knowledge yet are not exhaustive it is reasonable to
continue gathering and analyzing remediation optimization
experience.
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna
References
State Nuclear Regulatory Committee of Ukraine
More detailed information about post-Chernobyl
optimization experience and ReSCA use can be
provided by:
- Valeriy Kashparov - Ukrainian Scientific Institute of
Agriculture Radiology ([email protected])
- Volodymyr Berkovskyy – IAEA ([email protected])
More detailed information for remediation of aquatic
systems and lands can be provided by:
- Oleg Voitsekhovych - Ukrainian Hydrometeorological
Institute ([email protected])
56th Regular Session of the General Conference Senior Regulators’ Meeting
20 September, 2012 Austria, Vienna