Optimization of radiation protection at Bohunice NPP Ľubomír Dobiš Ján Kaizer Jaroslav Svitek

4th ISOE European Workshop, Lyon, 24-26 March 2004 Introduction Aim of the presentation: To provide the information about the status of optimization in Bohunice NPP Authors: Ľubomír Dobiš – RP manager, BSS 115 qualified expert, ISOE national coordinator Ján Kaizer – ALARA specialist Jaroslav Svitek – head of RP section 4th ISOE European Workshop, Lyon, 24-26 March 2004

Content of presentation Basic Slovak RP laws Influence of legislative requirements in NPP Description of optimization process and tools in Bohunice NPP Examples of optimization Conclusion 4th ISOE European Workshop, Lyon, 24-26 March 2004

Name Unit Operation V1 PWR, Unit 1, VVER-230 1978   PWR, Unit 2, VVER-230 1980 V2 PWR, Unit 3, VVER-213 1984 PWR, Unit 4, VVER-213 1985

4th ISOE European Workshop, Lyon, 24-26 March 2004 Slovak legislation The most important novelization of the state law No 272/94 “Protection of the People Health” by the law No 470/2000 Code of Ministry of Health No 12/2001 čo nám priniesol r. 2001? Obdobná vyhláška v ČR SÚJB č.18497 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 Law No 470/2000 2nd principle of radiation protection: Each person who performs the activity that leads to the exposure is obliged to ensure the magnitudes and likelihood of exposures and the numbers of individuals exposed be as low as reasonably achievable, economic and social factors being taken into account Other requirements are transmitted to the Code 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 Code 12/2001 - §4 Technical and organizational requirements to prove the Rational Achievable Level (RAL) of radiation protection. RAL are generally proved by the comparison of the dose distribution to the costs of protection Dose constraints collective dose 20 man mSv for the specific task, individual exposure 1 mSv per day 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 Code 12/2001 - §4 continued Alpha coefficients are used to calculate the benefit of the proposed measure. Alpha cofficients Individual exposure 2,40 mil. Sk / man Sv less 2 mSv/y 5,96 mil. Sk / man Sv 2 – 5 mSv/y 17,86 mil. Sk / man Sv 5 – 15 mSv/y 23,82 mil. Sk / man Sv 15 – 30 mSv/y 29,77 mil. Sk / man Sv 30 – 50 mSv/y 4th ISOE European Workshop, Lyon, 24-26 March 2004

Comparison of „α“ [man-sievert in US $] USA (NRC) Switzerland Czech republic Slovak republic 200 000 3 000 000 17 000 – 170 000 50 000 – 750 000 Source: SRS No.21, IAEA 2002, values given by the regulatory authorities 4th ISOE European Workshop, Lyon, 24-26 March 2004

Influence of state law requirements to Bohunice NPP Revision of plant documentation Transparent recording of optimization in Integration Information System (IIS) Bohunice NPP Problem solving of mathematical analysis through the collaboration with the external research institute 4th ISOE European Workshop, Lyon, 24-26 March 2004

Revision of plant documentation Revision of QA regulations Defining of new terms Optimization process Dose constraint – result of optimization process Target values (plant limits – ALARA criteria) – 10 manmSv, 1 mSv, 15 mSv Revision of technological procedures Completition of dose assessments into the procedures 4th ISOE European Workshop, Lyon, 24-26 March 2004

ALARA flowchart Calculation of doses – dose assessment Comparison with the ALARA criteria Recording facts into IIS - ALARA committee is necessary setting the dose constraints - work on RWP - without ALARA committee -work on RWP Evaluation of real exposures & feedback ARCHIVE 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 SW modul IIS - ALARA Goal: Transparent review of optimization Instrument to help the evaluation of optimization from Radiation Work Permits after performing works Put in operation in 2001 4th ISOE European Workshop, Lyon, 24-26 March 2004

Integration Information System IIS- Radiation Protection part 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 Optimization tools Generation and maintenance of optimization databases Quantitative analysis – OPTI RP Elaboration of sensitivity analysis 4th ISOE European Workshop, Lyon, 24-26 March 2004

Database for calculation of protection cost shielding decontamination waste processing protective aids salaries α coefficients 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 Comparison of the assessment of total costs-exchange of UFDSs inside SGs year 2001: Dr=7 mGy/h, DF=10 year 2002: Dr=8 mGy/h, DF=7 4th ISOE European Workshop, Lyon, 24-26 March 2004

Analysis of the assessment of costs in 2002 – exchange of UFDS 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 Sensitivity analysis – exchange of UFDS - example 4th ISOE European Workshop, Lyon, 24-26 March 2004

Sensitivity analysis – exchange of UFDS - example 4th ISOE European Workshop, Lyon, 24-26 March 2004

Calculation of price of exposure (UFDS, y. 2002) - example 4th ISOE European Workshop, Lyon, 24-26 March 2004

Optimized and real exposures for exchange of UFDSs inside SGs at V-1 Dose assessment before optimization Dose constrains for SG16 after optim. Real doses at SG16 Dose costrains for SG26 Real doses at SG26 Collective exposure [man mSv] 101,52 57,25 86,75* 25,18 39,71* 40,55 55,11* 28,60 35,57* Max. Individual exposure [mSv] 8,46 4,77 3,92 4,06 3,97 Max. daily exposure [mSv] 0,564 1,04 0,92 1,00 0,99   (*) including exposures for DECONTAMINATION and positioning of Pb shielding

Dose management during outages 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004 Conclusion Creation of transparent and understandable ALARA policy Acceptance of optimization by workers and managers Easy communication with the regulatory body Optimization of RP launch to be a part of safety culture 4th ISOE European Workshop, Lyon, 24-26 March 2004

4th ISOE European Workshop, Lyon, 24-26 March 2004

Thank you for your attention!