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Dose Assessment for Population around New NPP in Belarus. EMRAS II WG1 Meeting, “Reference Methodologies for Controlled Discharges” IAEA HQ, Vienna, 22-24 September 2009 Viktoryia Kliaus Minsk, Belarus. Where is Belarus situated? . RUSSIA. BELARUS. POLAND. UKRAINE.
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Dose Assessment for Population around New NPP in Belarus EMRAS II WG1 Meeting, “Reference Methodologies for Controlled Discharges” IAEA HQ, Vienna, 22-24 September 2009 Viktoryia Kliaus Minsk, Belarus
Where is Belarus situated? RUSSIA BELARUS POLAND UKRAINE
Factsabout Belarus • LOCATION- Eastern EuropeAn 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 Nuclear and Radiation Safety Council of Ministers National Commission of Radiation Protection Ministry of Health Ministry of Ecology Ministry of Emergency Situations Department of Nuclear and Radiation safety • 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 • Licensing According to the Law “About Radiation Safety of Population”
NPP in Belarus • Type: NPP-2006; • Reactor: WWR (PWR)-1200; • General contractor: “Atomstroieksport” (Russia); • Possible location: Ostrovets, Kukshinovo, Krasnaya Polyana areas; • Planned construction time: 54 month; • Lifetimeat 90% capacity factor : expected 50 years; • The WWR 1200 will produce: 1200 MW(e) electric power and 3200 MW(th) heat power. Ostrovets area Vitebsk Kukshinovo area Minsk Mogilev Grodno Krasnaya Polyana area Gomel Brest Possible location of the NPP
NPP in Belarus • Safety features: containment building and missile shield; • Dose for public during normal operation: 100 µSv/year; • During normal operation such types of NPP make an insignificant impact on environment (radiation impact no more than 0,1 – 0,01from background radiation level). Model of the Belarusian NPP
Regulatory limit values Dose limits in planned exposure situations According to the Standards of Radiation Safety-2000
Regulatory limit values Values of radioactive discharges from NPP with WWR-1000 in case of normal operation
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 ‘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 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) So Today Belarus revises National Standards according to the new ICRP concept of the ‘representative person’ Permissible Levels of Concentration of Radionuclides in Food Products Standards of Radiation Safety-2000 Main Hygienic Rules and Norms-2002 The Concept of the ‘Representative Person’
Dose 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
Effective Dose from Ingestion 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. The dose from consumption of food or dirt:
Effective Dose from Ingestion Consumption of milk, l/day Consumption of milk products, g/day
Effective Dose from Ingestion Consumption of leaf vegetables, g/day Ingestion dose conversion, mSv/kBq
Effective Dose from Inhalation E ing – Effective dose from inhalation, mSv Cair – concentration of radionuclide in the air, Bq/m3 DCF – effective inhalation dose conversion factor for adults, Sv/Bq BR – breathing rate, m3/h t – exposure durations, h The effective dose from inhalation
Effective Dose from Inhalation Breathing rate
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 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. 0,1 µSv/h Natural dose rate
Summary For dose assessment of population around new NPP in Belarus from internal and external exposureare used: • methods based on the monitoring of radiation situation round the NPP; • peculiarity of food consumed by the population round the NPP.