Current Status of Radiological Protection in NPPs of Korea

Transcription

1 2010_ISOE_Asian ALARA Symposium Current Status of Radiological Protection in NPPs of Korea Byoung-il, Lee Korea Hydro & Nuclear Power Co., LTD Radiation Health Research Institute

2 Contents National accreditation program of radiation dosimetry system NPP s dosimetry system NPP s ALARA program Exposure trends of NPP workers 3 RHRI s activity for NPP s RP

3 Current Status of Radiological Protection in NPPs in Korea National accreditation program of radiation dosimetry system KHNP - Radiation Health Research Institute

4 National accreditation program of radiation dosimetry Sys Ministry of Education, Science & Technology Korea Institute of Nuclear Safety Dose quality & Radiation safety control Dose Registry Korea Radio-Isotope Association Yearly inspection Yearly blind test with unknown TLD Nuclear Power Plants yearly report Internal dose Quarterly report External dose Monthly TLD reading Yearly blind test with unknown bioassay sample by RHRI Yearly professional training of EX/IN dose assessment by RHRI Every two reactors have a TLD reading facility and an internal dosimetry facility

5 Legislation of dose quality control External dosimetry Reader < 6 months Chip < 2 years Algorithm < 6 months Routine check < 1 month Periodic check < 6 months Reader QC Calibration Performance Criteria ANSI N [8 Criteria-blind test < 1 year] Procedure Quality Assurance Manual Technical Skills Training < 1 year LLD Lower Limit of Detection TLD < 0.10 msv Reader quality management Reader & Chip calibration Algorithm operation Chip reading, annealing & management Management of system & document Management of person in charge

6 Legislation of dose quality control Internal dosimetry Workers required bioassay Management of document Internal Dosimetry legislation Measurement method Bioassay Internal dose assessment If unobtainable, Air sampling Requirements of the bioassay system Procedure System operation Technical skills Surveillance and calibration Dose evaluation

7 Current Status of Radiological Protection in NPPs in Korea NPP s dosimetry system KHNP - Radiation Health Research Institute

8 Present state of nuclear power plants in Korea Kori unit 1 started commercial operation in 1978 The first Korea Standard Nuclear Power Plant(Ulchin unit 3, OPR-1000) completed the construction in1998 The first concrete casting for 1.4 million kw-level(apr-1400) Shin-Kori uint 3 in units in operation (16-PWR, 4-PHWR) 24 % of power facility & 36 % of electricity use

9 NPP s dose registry system Dose control Optimal radiation protection Dose report to the MEST Dose statistics ERP(RAM) System Management of radiation workers Designation of radiation worker Issue of radiation work permit Control of RCA entrance / exit Radiation dose registry External Shallow, deep, neutron, extremity Internal

10 NPP s radiation exposure control Start Radiation Work Permit? Yes γ, β emitters? Satisfaction of the dose limit, training, medical test, WBC or H-3 check No Exposure exceeding 4 msv, & 2 times of whole body dose + Neutron Non-homogeneous Exposure Exposure exceeding 3 msv, & 1.5 times of chest dose, & Dose rate exceeding 1mSv/hr Yes Wearing the Neutron TLD & PD Homogeneous Exposure? Yes No Wearing the extremity TLD Extremity? Yes No Whole body 1 Wearing the additional TLD & Alarm dosimeter (Chest & Back)

11 NPP s radiation exposure control 1 Wearing the Chest TLD & Alarm dosimeter Airborne Radioactive Materials > 1 DAC No Yes Wearing the mask RCA Control system RWP & Dose & Entrance requisite ERP(RAM) System 2

12 NPP s radiation exposure control 2 Radiation work RCA Control system Alarm dosimeter dose & Work record ERP(RAM) System Abnormal situation of alarm dosimeter? Yes TLD dose reading promptly No 3 When alarm dosimeter is lost / destroyed or displayed over-range / higher dose

13 NPP s radiation exposure control 3 Abnormally exposed worker? Yes Site inspection - Dose rate & energy measurement - Simulation of work situation - Fellow s dose & interview No No > Dose Limit? Yes Worker who exceeded annual dose limit or lost / destroyed his personal dosimeter 4 Professional institute (RHRI) Biological or mathematical dose reconstruction National dose evaluation committee Determination of the abnormally exposed worker s dose

14 NPP s radiation exposure control - Working in the airborne radioactive materials or high contamination area - When nose contamination is detected 4 PHWR? No Necessity of the internal dosimetry? No Yes Yes Urine analysis for H-3 WBC LSC TLD reading monthly RAM System Non-homogeneous Exposure H E = 0.55[H P (10)] (chest) [H P (10)] (Back) End

15 Current Status of Radiological Protection in NPPs in Korea NPPs ALARA Program KHNP - Radiation Health Research Institute

16 Laws regarding ALARA Korea atomic energy law 1995 : Adoption of the ALARA concept Release quantities of radioactive material to the environment and occupational radiation doses are maintained ALARA Enforcement Ordinance 1999 : Requirement to implement ALARA MEST notice 2000 : Requirement to implement ALARA

17 KHNP s ALARA program Equipment improvements for ALARA in existing NPP KHNP has performed a substantial amount of equipment improvements in order to meet the dose limitations PSAR preliminary safety analysis report ALARA Design of Korea standard nuclear power plant KSNPs are being constructed with an enhanced design based on the experiences of the existing plants. Year of 2008, average individual dose 1.1 msv/yr KSNP 0.5 msv/yr

18 KHNP s ALARA program ALARA Procedure in operating NPP Any Works Expected dose Under 10 man-msv Expected Dose 10 ~ 70 man-msv Expected Dose 70 ~ 200 man-msv Expected Dose Over 200 man-msv Use general RWP - Use RWP - Evaluate expected dose Work group should make - Expected Dose sheet and ALARA check list ALARA Subcommittee( Committee) Review & approve Feedback Review after works and If actual dose exceeds 25% of expected dose ALARA subcommittee (Committee) Review, discuss & apply : dose reduction method to repeated works

19 Current Status of Radiological Protection in NPPs in Korea Exposure trends of NPP workers KHNP - Radiation Health Research Institute

20 Dose distribution by operation state (1990 ~ 2007) Refueling 77 % Normal operation 23 %

21 Dose distribution by exposure type (1990 ~ 2007) Neutron dose 2.7 % Internal dose 5.3% PWR 0.01% Gamma 92.0 %

22 Annual individual dose trend of NPP workers

23 Radiation dose distribution of NPP workers Year

24 Annual collective dose trend of NPP workers (man/unit)

25 WANO PI report

26 Current Status of Radiological Protection in NPPs in Korea RHRI s Activity for NPP s RP KHNP - Radiation Health Research Institute

27 Radiation emergency medical preparedness for NPP WHO/REMPAN Liaison Institute 24hr Emergency Response Program Maintenance of REMP system with NPP appointed hospitals Education/ Training Program -Primary H. Secondary H. * REMP : Radiation Emergency Medical Preparedness

28 Accidental dose evaluation system Decision-making for the treatment of patient caused by radiation exposure Biological Assessment CA, FISH, MN, PCC Radiation Dose Assessment Clinical Evaluation Clinic symptoms Physical Assessment ESR, WBC, LSC Body Activation Analysis Mathematical Assessment MCNP, VOXEL

29 Electron Spin Resonance System Tooth Ring Watch C.P. Sugar Spectrum in teeth Ceramics Dose response curve Quartz

30 Body Activation Analysis System 血液分析 NPP 照射 AAS HPGe Neutron spectrum : Excel 開發 Modified BOMAB : 製作 Water Slab Phantom : 製作 BSS KBADA Dose assessment S/W:Visual Basic 開發 MCNP-X 模寫 線量評價

31 Development of Korean Phantom

32 Study on internal dosimetry Fast Scan MCNP Accu-Scan HPGe CRM 改善 Inter-Comparison Korean Phantom 開發 Measurement system 構築 Technical support about Internal dosimetry for NPPs in Korea Guideline Guide Training of IDEAS Guideline Wound model Guide S/W 開發 NPP members

33 Radiation dose reconstruction, PC calculation & epidemiologic investigation Program for Estimating Probability of Causation

34 Low dose radiation research

35 Application study of ICRP new recommendation 2011(?) (?)

36 Korea Hydro & Nuclear Power Co., LTD Radiation Health Research Institute