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