1. 1
Recommendations to the Governments of
Belarus, the Russian Federation and Ukrania
on
environmental monitoring,
remediation and research.
Summary by
The Chernobyl Forum
Vienna International Center; Vienna, Austria; September 6th
, 2005
Abel J. González
Autoridad Regulatoria Nuclear; Av. Del Libertador 8250; Buenos Aires; ArgentinaAutoridad Regulatoria Nuclear; Av. Del Libertador 8250; Buenos Aires; Argentina
+54 1163231306;+54 1163231306; agonzale@sede.arn.gov.aragonzale@sede.arn.gov.ar
4. Environmental monitoring
and research
Environmental transfer and bioaccumulation of 137
Cs
and 90
Sr are now well understood
Little need for major new research programmes
Requirement for continued but more limited targeted
monitoring of the environments
5. Environmental monitoring
and research
Long term monitoring of 137
Cs and 90
Sr) is required to:
(Practical)
To assess levels of human exposure and contamination of
foods to determine the need for remedial actions;
To inform the general public about the radioactive
contamination in food products and its seasonal and annual
variability in natural food products as well as give dietary
advice.
6. Environmental monitoring
and research
Long term monitoring of 137
Cs and 90
Sr) is required to:
(Scientific)
To determine parameters of long-term transfer of radionuclides
in various ecosystems and different natural conditions to
improve predictive models;
To determine mechanisms of radionuclide behaviour in less
studied ecosystems (e.g., role of fungi in the forest).
8. Remediation and countermeasures
Different effective long-term remediation measures
are available,
but their use should be justified and optimized.
The general public should be informed and involved
in the decision-making process.
10. INTERVENTIONINTERVENTION
MAY POSSIBLY BEMAY POSSIBLY BE
JUSTIFIABLEJUSTIFIABLE
INTERVENTIONINTERVENTION
IS NOT LIKELY TOIS NOT LIKELY TO
BE JUSTIFIABLEBE JUSTIFIABLE
INTERVENTIONINTERVENTION
ALMOST ALWAYSALMOST ALWAYS
JUSTIFIABLEJUSTIFIABLE
mSv/year
100
EXTANTEXTANT
ANNUALANNUAL
DOSEDOSE
TYPICALLY HIGHTYPICALLY HIGH
AVERAGEAVERAGE
NATURAL
BACKGROUND
VERY HIGHVERY HIGH100
11. Remediation and countermeasures
Remediation measures on radiocaesium in soil may
be justified in agricultural areas with sandy and peaty
soils where there might be a high transfer from soil
to plants.
12. Remediation and countermeasures
Efficient regular agricultural countermeasures are:
Radical improvement of pastures and grasslands as well as
draining of wet peaty areas may be an effective remediation
measure
Enhanced application of mineral fertilisers in plant breeding,
application of Prussian Blue to cattle and pre-slaughter clean
feeding accompanied with in-vivo monitoring.
13. Remediation and countermeasures
There are still agricultural areas in the three
countries which are out of use. However this land
can be safely used after appropriate remediation.
14. Remediation and countermeasures
Restricting harvesting of wild food products such as
game, berries, mushrooms and fish from ‘closed
lakes’ by the public may still be needed.
15. Remediation and countermeasures
It is unlikely that any future countermeasures to
protect surface waters will be justifiable.
Restrictions on consumption of fish may remain in a
few closed lakes.
23. 23
September 2000:
IAEA General Conference, following a request
from Belarus, decided the development of
radiological criteria for
radionuclides in commodities.
24. Board of Governors
General Conference
GOV/2004/54-GC(48)/8
Date: 30 July 2004
General Distribution
Original: English
For official use only
Item 3(c) of the Board's provisional agenda
(GOV/2004/51)
Item 13 of the Conference's provisional agenda
(GC(48)/1)
Measures to Strengthen International Co-operation in
Nuclear, Radiation and Transport Safety and Waste
Management
Radiological Criteria for Radionuclides in
Commodities
Report by the Director General
27. Codes Alimentarious levels
(incorporated into the BSS as
generic action levels for foodstuffs)
action levels (Bq/kg)
Radionuclides
Food destined for
general consumption
Milk, infant foods and
drinking water
134,137
Cs, 103,106
Ru, 89
Sr 1,000
131
I
1,000
90
Sr 100
100
241
Am, 238,239
Pu 10 1
28. Guideline levels for radionuclides in foods
Radionuclides in foods Guideline Level
(Bq/kg)
238
Pu, 239
Pu, 240
Pu, 241
Am 1
90
Sr, 106
Ru,129
I,131
I, 235
U 100
35
S,60
Co, 89
Sr, 103
Ru, 134
Cs, 137
Cs, 144
Ce, 192
Ir 1000
3
H*, 14
C, 99
Tc 10000
30. Environmental aspects of the shelter
dismantlement and radioactive waste management
A comprehensive safety and environmental
impact assessment should be performed.
Development of an integrated radioactive waste
management programme for the Shelter.
Strategy for rehabilitation of the Exclusion
Zone
Overall plan for the long-term development of
33. Detectability limits in radioepidemiology
Because radiation is a
weak carcinogen,
it is practically impossible
to detect effects at
low doses.
34. 34
Control group
““NN” people” people
““CC” cancers” cancers
““nn” probability of” probability of
‘natural’ cancer‘natural’ cancer
Exposed group
““NN” people” people
““EE” cancers” cancers
““nn” probability of” probability of
‘natural’cancer‘natural’cancer
‘‘ppDD’’ probability ofprobability of
‘radiation’ cancer‘radiation’ cancer
35. Epidemiological significance
The expected number of cancers in the control group will be:
C = n N
The expected number of cancers in the exposed group will be:
E = n N + pd D N
The expected number of excess cancers will be
36. 36
E
= n N
+
pd D N
Number
of
cancers
in
exposed
group
C
=n N
Number
of
cancers
in
control
group
E-C
Difficult to
detect!
37. Epidemiological significance
The standard deviation is
σ = √ 2 n N + pd D N
If the excess cancers are to be detected with a statistical
confidence of 95%
E – C > 2 σ
38. Epidemiological significance
Operating algebraically and as n >> pd D,
N > constant / D2
which is the equation giving the number of people, N,
needed for detecting excess cancers at dose D.
(Constant = 8 n / pd
2
)
39. 39
10 2
10 1
10-0
10-1 10 2
10 4
10 6
10 8
Dose (mSv)Dose (mSv)
PeoplePeople
Region of detectability
Region of undetectability
1 mSv1 mSv
10 9
p.
DETECTABILITY OF SOLID CANCERS
40. 40
10 2
10 1
10-0
10-1 10 2
10 4
10 6
10 8
Dose (mSv)Dose (mSv)
PeoplePeople
Region of detectability
Region of undetectability
Chernobyl dosesChernobyl doses
~50 mSv~50 mSv
PopulationPopulation
~270 000~270 000
DETECTABILITY OF SOLID CANCERS
42. Thyroid cancer in children in Belarus
Thyroid cancer in children in BelarusThyroid cancer in children in Belarus
Thyroid cancer in children in Belarus
0
20
40
60
80
100
120
140
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
Numberofcases
Total
0-4
5-9
10-14
43. 43
10 2
10 1
10-0
10-1 10 2
10 4
10 6
10 8
Dose (mSv)Dose (mSv)
PeoplePeople
Region of
detectability
Region of undetectability
~10 mSv~10 mSv
DETECTABILITY OF HEREDITABLE EFFECTS
~10~101010
people!people!
44. 44
10 2
10 1
10-0
10-1 10 2
10 4
10 6
10 8
Dose (mSv)Dose (mSv)
PeoplePeople
Region of detectability
0.001 Sv0.001 Sv
100.000.000 p.100.000.000 p.
100.000 man Sv x 5%/Sv = 5000 deaths!100.000 man Sv x 5%/Sv = 5000 deaths!
45. 45
10 2
10 1
10-0
10-1 10 2
10 4
10 6
10 8
Dose (mSv)Dose (mSv)
PeoplePeople
Region of detectabilityRegion of detectability
Do the effects in this
region actually occur?Epistemological Limitation
Epistemological Limitation
No grounds of knowledge!!
No grounds of knowledge!!
47. 47
Responding to this demand, three years ago, the
IAEA General Conference requested that
commodities requiring regulatory control shall be
identified.
THE INTERNATIONAL ATOMIC ENERGY AGENCY
48. 48
If it is satisfied that the doses of
radiation incurred will be trivial,
the competent authority should
waive the requirements of …… :
…operations which do not
involve the use of radioactive
substances at concentrations
exceeding 0.002 µCi/g (74 Bq/g)
or solid natural radioactive
substances at concen-trations
exceeding 0.01 µCi/g (370 Bq/g).
49. 49
I.e., it can be construed that the first BSS applied to
controllable operations involving radioactive
substances at concentrations exceeding
some 10’s of Bq/g!
54. 54
Not surprisingly,
people (and their representatives)
have been asking a simple basic question to the
radiation protection community:
What is the radioactivity level below which the
commodities are safe to be used without any control?
55. 55
Commodities carry
becquerels (or curies)
NOT
sieverts (or rems)
Therefore, levels should be derived in terms of Bq/kg
rather than in terms of hypothetical individual doses.
56. 56
Our problem is
to provide a rational, logical and
sustainable answer to these simple
questions!
57. 57
10 2
10 1
10-0
10-1 10 2
10 4
10 6
10 8
Dose (mSv)Dose (mSv)
PeoplePeople
Region of detectability
Region of undetectability
Liquidators’ av.dosesLiquidators’ av.doses
~10 mSv~10 mSv
Chernobyl liquidatorsliquidators
~160 000~160 000
DETECTABILITY OF LEUKÆMIAS
58. Relatively low doses:
Exposure of residents affected by Chernobyl
Average doses
(1986-1995)
External Internal Total
Russian Federation 4 2.5 6.5 mSv
Belarus 5 3 8 mSv
Ukraine 5 6 11 mSv
Average (10 years) 5 3 8 mSv
(lifetime) 9 4 13 mSv
Editor's Notes
International recommendations from BSS/IAEA
The recommended generically optimised action levels for agricultural countermeasures from the BSS/IAEA are shown in this slide. These values have been selected in general towards the middle of each range of optimised action levels and they have deliberately been given the same numerical values as those recommended by FAO/WHO Codex Alimentarius Commission for concentrations of activity in foodstuffs moving in international trade. The FAO/WHO values should be seen as non-action levels or intervention exemption levels. The levels are in close agreement to the action level derived from the simple cost-benefit analyses just shown in the previous slide.
The basis upon which decisions to suspend prolonged remedial measures should be made would therefore, at least conceptually, be the same as that for their initial introduction. After suspension of a remedial measure the situation should be considered as normal.
Return to normality in situations involving chronic exposures would be addressed in the following general intervention situations:
remedial measures have been taken
remedial measures have been considered, but not taken
suspension of remedial measures already taken
Return to ‘normality’ or re-establishing ‘normal conditions’ after the implementation of remedial measures has often been misinterpreted as a return to the situation that prevailed before the contamination occurred. This view seems to be in conflict with the System of Protection for interventions which only deals with dose reductions and consequently not with the pre-intervention situation. Residual doses would therefore be considered ‘normal’ seen from a radiation protection point of view. If, however, the post-intervention individual doses are so high that there is a risk of deterministic effects or a high risk of stochastic effects, further interventions, e.g., relocation or restrictions on the use of the area will need to be established. In general, normal conditions means that members of the public can live and/or work in the area under consideration without any restrictions associated with the residual exposure.
The basis upon which decisions to suspend prolonged remedial measures should be made would therefore, at least conceptually, be the same as that for their initial introduction. After suspension of a remedial measure the situation should be considered as normal.
Return to normality in situations involving chronic exposures would be addressed in the following general intervention situations:
remedial measures have been taken
remedial measures have been considered, but not taken
suspension of remedial measures already taken
Return to ‘normality’ or re-establishing ‘normal conditions’ after the implementation of remedial measures has often been misinterpreted as a return to the situation that prevailed before the contamination occurred. This view seems to be in conflict with the System of Protection for interventions which only deals with dose reductions and consequently not with the pre-intervention situation. Residual doses would therefore be considered ‘normal’ seen from a radiation protection point of view. If, however, the post-intervention individual doses are so high that there is a risk of deterministic effects or a high risk of stochastic effects, further interventions, e.g., relocation or restrictions on the use of the area will need to be established. In general, normal conditions means that members of the public can live and/or work in the area under consideration without any restrictions associated with the residual exposure.
