dose assessment for population around new npp in belarus emras ii wg1 meeting, “reference...
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Dose Assessment Dose Assessment for Population for Population
around New NPP in around New NPP in BelarusBelarus
EMRAS II WG1 Meeting, EMRAS II WG1 Meeting,
““Reference Methodologies for Controlled Reference Methodologies for Controlled Discharges”Discharges”
IAEA HQ, Vienna, IAEA HQ, Vienna,
22-24 September 200922-24 September 2009
Viktoryia KliausViktoryia Kliaus
Minsk, BelarusMinsk, Belarus
Where is Belarus situated? Where is Belarus situated?
POLANDPOLAND
FactsFacts about Belarusabout Belarus LOCATION - Eastern Europe
An inland country. It is surrounded by Lithuania and Latvia to the northwest and Russia to the north and east. Ukraine lies to the south and southeast and Poland to the west
TIME - GMT +2 AREA - 207,595 sq km (80,153 sq miles) POPULATION - 9,7 million (2009) CAPITAL CITY - Minsk - Population 1,7
million CURRENCY - Belarus Rubel (BYB) LANGUAGE(S) - Belarussian and Russian RELIGION(S)
Christian with an Eastern Orthodox and Roman Catholic majority, Jewish and Muslim minorities
Minsk
The Competence of State Organizations in the Area of The Competence of State Organizations in the Area of Nuclear and Radiation SafetyNuclear and Radiation Safety
Council of Ministers
National Commission of
Radiation Protection
According to the Law “About Radiation Safety of Population”
Ministry of
Emergency Situations
Ministry of Health
Ministry of Ecology
•Approve medical standards, rules and hygienic norms•Established the unified system of control and registration of individual doses
•Organize carrying out of the radiation monitoring of environment
Department of Nuclear
and Radiation
safety•Licensing
NPP in BelarusNPP in Belarus
Possible location of the NPP
Type: NPP-2006; Reactor: WWR (PWR)-1200; General contractor: “Atomstroieksport” (Russia);Possible location: Ostrovets, Kukshinovo, Krasnaya Polyana areas; Planned construction time: 54 month;Lifetime at 90% capacity factor : expected 50 years; The WWR 1200 will produce: 1200 MW(e) electric power and 3200 MW(th) heat power.
Grodno
Brest
Minsk
Vitebsk
Mogilev
Gomel
Ostrovetsarea
Kukshinovo area
Krasnaya
Polyanaarea
NPP in BelarusNPP in Belarus
Safety features: Safety features: containment building containment building and missile shield;and missile shield;
Dose for public during Dose for public during normal operation: normal operation: 100 100 µSv/year;µSv/year;
During normal During normal operationoperation such types of such types of NPP make an NPP make an insignificant impact on insignificant impact on environment environment ((radiation radiation impact no more than impact no more than 0,1 0,1 – 0,01– 0,01 from background radiation level))..
Model of the Belarusian NPP
Regulatory limit valuesRegulatory limit values
Type of limit Dose limits
Occupational Public
Effective dose 20 mSv/year, averaged over
defined periods of 5 years, but it should
not exceed 50 mSv in any single year
1 mSv/year for any consistent 5 years, but it should not
exceed 5 mSv in any single year
Dose limits in planned exposure situations
According to the Standards of Radiation Safety-2000
Regulatory limit valuesRegulatory limit values
NPP
Rare radioactive
gases
I-131 Со-60 Сs-134 Сs-137
ТBq (% from leakage)
MBq (% from leakage)
NPP with WWR-1000 and WWR-440
Novovoronezhskaya
110 (16)1700 (9,4)
350 (4,7) 41 (4,6) 140 (7)
Kolskaya 4,2 (0,6) 134 (0,7) 88 (1,2) 0,01 53 (2,7)
Rostovskaya 0,2 (0,02) 57 (0,3)0,8
(0,01)0,2
(0,03)0,1
(0,01)
Balakovskaya 0,2 (0,02) 223 (1,2) 7,7 (0,1) 2,4 (0,3) 7 (0,4)
Kalininskaya 49 (7) 512 (2,8) 4,1(0,1) 0,7 (0,1) 1,8 (0,1)
Values of radioactive discharges from NPP with WWR-1000 in case of normal operation
The Concept of ‘Critical Group’The Concept of ‘Critical Group’
The ‘critical group’ concept is used for the purpose of protection of the public in Belarus to characterize an individual who is representative of the most highly exposed individuals in the population (ICRP 1977, 1985);
It is important to consider some aspects : The location and age distribution of the potentially exposed
group; Dietary habits; Special occupational habits; The type of dwelling; Behavior factor.
The Concept of the ‘The Concept of the ‘Representative Person’
For the purpose of protection of the public, it is necessary to characterize an individual who is representative of the most highly exposed individuals in the population. This individual is defined as the ‘representative person’.
The representative person may be hypothetical. Nevertheless, it is important that the habits used to characterize the representative person are typical habits of a small number of individuals representative of those most highly exposed and not the extreme habits of a single member of population.
The Concept of the ‘The Concept of the ‘Representative Person’
Today Belarus revises National Standards according to the new ICRP concept of the
‘representative person’
So
The Commission now recommends the use of the ‘representative person’ for the purpose of
radiological protection of the public instead of the earlier critical group concept (ICRP, 2006b)
Permissible Levels of Concentration
of Radionuclides in Food Products
Standards of Radiation
Safety-2000
Main Hygienic Rules and
Norms-2002
Dose assessment processDose assessment process
Sum to give annual effective dose for critical
group
Total Effective Dose
Total Effective Dose
ET = total effective dose
Eext = effective dose from external radiation
Einh = committed effective dose from inhalation
Eing = committed effective dose from ingestion
T ext inh ingE E E E
Effective Dose from Effective Dose from IngestionIngestion
The dose from consumption of food or dirt:The dose from consumption of food or dirt:
n
iingfiifiif ERFCFDIUC )( ,5,
Eing – Effective dose from ingestion, mSv;Сf,i –Activity concentration in food of isotope i , kBq/kg;Uf,i –The amount of a food consumed by the population of interest, per day;CF5,i – Ingestion dose conversion, mSv/kBq;DIi – Days of intake is the period food is assumed to be consumed. If T1/2 > 21 days use 30 days. If T1/2 < 21 days use the mean life (Тm) of the isotope.
Т1/2 – Radiological half-life;RF – Reduction Factor is the fraction of the contamination remaining after decay or some process j used to reduce the contamination before food is released for consumption.
44.12/1 TTm
Effective Dose from Effective Dose from IngestionIngestion
Age, year
s
Rural populatio
n
Urban populati
on
<1 0,24 0,30
1-2 0,30 0,22
2-7 0,30 0,20
7-12 0,50 0,25
12-17
0,51 0,25
>17 0,50 0,20
Consumption of milk, l/day
Consumption of milk products, g/day
Age, years
Rural populatio
n
Urban populati
on
<1 10 70
1-2 75 130
2-7 85 145
7-12 190 175
12-17 230 180
>17 260 180
Effective Dose from IngestionEffective Dose from Ingestion
Age, year
s
Rural populatio
n
Urban populati
on
<1 0 0
1-2 3 3
2-7 6 7
7-12 20 18
12-17
28 25
>17 30 25
Consumption of leaf vegetables, g/day
Age, years
Radionuclide
Cs-137 I-131
<1 2,1E-02 1,8E-01
1-2 1,2E-02 1,8E-01
2-7 9,6E-03 1,0E-01
7-12 1,0E-02 5,2E-02
12-17 1,3E-02 3,4E-02
>17 1,3E-02 2,2E-02
Ingestion dose conversion, mSv/kBq
Effective Dose from Inhalation
The effective dose from inhalationThe effective dose from inhalation
1000 tBRDCFCE airinh
E ing – Effective dose from inhalation, mSvCair – concentration of radionuclide in the air, Bq/m3
DCF – effective inhalation dose conversion factor for adults, Sv/BqBR – breathing rate, m3/ht – exposure durations, h
Effective Dose from Inhalation
Breathing rate
Age, years Breathing rate, m3/h
<1 2.86
1-2 5.17
2-7 8.72
7-12 14.2
12-17 20.11
>17 22.22
Doses from External Radiation
Thus external exposure is possible from the cloud with the radionuclides which are released from installations, by being on radioactively contaminated soil or swimming in contaminated water;
The doses can be calculated from the activity concentrations in the environment by modeling and computation.
Doses from External Radiation
Natural dose rate
0,1 µSv/h
Additional dose rate from the new
NPP activity
As planning doses levels are very low it will be a big uncertainties of dose assessment;
The critical group will be persons who spend a lot of time outside.
SummaryFor dose assessment of population around
new NPP in Belarus from internal and external exposure are used:
methods based on the monitoring of radiation situation round the NPP;
peculiarity of food consumed by the population round the NPP.
Thank You Thank You for Your for Your AttentionAttention