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2010_ISOE_Asian ALARA Symposium Current Status of Radiological Protection in NPPs of Korea 2010. 8. 31 Byoung-il, Lee Korea Hydro & Nuclear Power Co., LTD Radiation Health Research Institute. 3. 3. 3. 3. 3.
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2010_ISOE_Asian ALARA Symposium Current Status of Radiological Protection in NPPs of Korea 2010. 8. 31 Byoung-il, Lee Korea Hydro & Nuclear Power Co., LTD Radiation Health Research Institute
3 3 3 3 3 National accreditation program of radiation dosimetry system Contents NPP’s dosimetry system NPP’s ALARA program Exposure trends of NPP workers RHRI’s activity for NPP’s RP
Current Status of Radiological Protection in NPPs in Korea KHNP - Radiation Health Research Institute National accreditation program of radiation dosimetry system
Korea Radio-Isotope Association Korea Institute of Nuclear Safety Ministry of Education, Science & Technology Dose quality & Radiation safety control yearly report Internal dose Quarterly report External dose • National accreditation program of radiation dosimetry Sys Dose Registry Yearly inspection Yearly professional training ofEX/IN dose assessment by RHRI Yearly blind test with unknown TLD Monthly TLD reading Nuclear Power Plants Yearly blind test with unknown bioassay sample by RHRI Every two reactors have a TLD reading facility and an internal dosimetry facility
Legislation of dose quality control – External dosimetry Routine check < 1 month Periodic check < 6 months ANSI N 13.11 [8 Criteria-blind test < 1 year] Perfor- mance Criteria Reader QC Reader < 6 months Chip < 2 years Algorithm < 6 months Calib- ration Quality Assurance Manual Technical Skills Training < 1 year Proce- dure LLD Reader quality management Reader & Chip calibration Algorithm operation Chip reading, annealing & management Management of system & document Management of person in charge Lower Limit of Detection TLD < 0.10 mSv
Internal dose assessment • Legislation of dose quality control – Internal dosimetry Management of document Measurement method Workers required bioassay Internal Dosimetry legislation If unobtainable, Air sampling Bioassay Procedure Requirements of the bioassay system System operation Technical skills Surveillance and calibration Dose evaluation
Current Status of Radiological Protection in NPPs in Korea KHNP - Radiation Health Research Institute NPP’s dosimetry system
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-Koriuint 3 in 2008 24 % of power facility & 36 % of electricity use 20 units in operation (16-PWR, 4-PHWR)
Dose report to the MEST Dose statistics External • NPP’s dose registry system Dose control Optimal radiation protection ERP(RAM) System Shallow, deep, neutron, extremity Issue of radiation work permit Management of radiation workers Radiation dose registry Internal Designation of radiation worker Control of RCA entrance / exit
Whole body + Neutron • NPP’s radiation exposure control Start Satisfaction of the dose limit, training, medical test, WBC or H-3 check Non-homogeneous Exposure Exposure exceeding 3 mSv, & 1.5 times of chest dose, & Dose rate exceeding 1mSv/hr Radiation Work Permit ? Exposure exceeding 4 mSv, & 2 times of whole body dose Yes No γ, β emitters ? Yes Wearing the Neutron TLD & PD No No Homogeneous Exposure ? Extremity ? Yes Wearing the extremity TLD Yes Wearing the additional TLD & Alarm dosimeter (Chest & Back) 1
Wearing the Chest TLD & Alarm dosimeter Wearing the mask RCA Control system • NPP’s radiation exposure control 1 Airborne Radioactive Materials > 1 DAC Yes No ERP(RAM) System RWP & Dose & Entrance requisite 2
Radiation work RCA Control system • NPP’s radiation exposure control 2 ERP(RAM) System Alarm dosime- ter dose & Work record Yes Abnormal situation of alarm dosimeter ? TLD dose reading promptly No When alarm dosimeter is lost / destroyed or displayed over-range / higher dose 3
Professional institute (RHRI) National dose evaluation committee • NPP’s radiation exposure control 3 Site inspection - Dose rate & energy measurement - Simulation of work situation - Fellow’s dose & interview Yes Abnormally exposed worker ? No No > Dose Limit ? Yes Biological or mathematical dose reconstruction Worker who exceeded annual dose limit or lost / destroyed his personal dosimeter Determination of the abnormally exposed worker’s dose 4
End TLD reading monthly • NPP’s radiation exposure control Urine analysis for H-3 4 • Working in the airborne • radioactive materials or • high contamination area • When nose contamination • is detected Yes LSC PHWR ? No WBC Yes Necessity of the internal dosimetry ? No RAM System Non-homogeneous Exposure HE= 0.55[HP(10)] (chest) + 0.50 [HP(10)] (Back)
Current Status of Radiological Protection in NPPs in Korea KHNP - Radiation Health Research Institute NPPs’ ALARA Program
Korea atomic energy law MEST notice Enforcement Ordinance • Laws regarding ALARA 1995 : Adoption of the “ALARA” concept Release quantities of radioactive material to the environment and occupational radiation doses are maintained ALARA 1999 : Requirement to implement “ALARA”” 2000 : Requirement to implement “ALARA””
Equipment improvementsfor ALARA in existing NPP PSAR • KHNP’s ALARA program • KHNP has performed a substantial amount of equipment • improvements in order to meet the dose limitations 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
ALARA Procedure in operating NPP • KHNP’s ALARA program Any Works Expected Dose 10 ~ 70 man-mSv Expected Dose 70 ~ 200 man-mSv Expected Dose Over 200 man-mSv Expected dose Under 10 man-mSv • - Use RWP • Evaluate expected dose Use general RWP Work group should make - Expected Dose sheet and ALARA check list ALARA Subcommittee( Committee) Review & approve Review after works and If actual dose exceeds 25% of expected dose Feedback ALARA subcommittee (Committee) Review, discuss & apply : dose reduction method to repeated works
Current Status of Radiological Protection in NPPs in Korea KHNP - Radiation Health Research Institute Exposure trends of NPP workers
Dose distribution by operation state (1990 ~ 2007) Normal operation 23 % Refueling 77 %
Dose distribution by exposure type (1990 ~ 2007) Neutron dose 2.7 % Internal dose 5.3% PWR 0.01% Gamma 92.0 %
Radiation dose distribution of NPP workers ≥20 ≥15 ≥10 Year
Annual collective dose trend of NPP workers (man/unit)
Current Status of Radiological Protection in NPPs in Korea KHNP - Radiation Health Research Institute RHRI’s Activity for NPP’s RP
Radiation emergency medical preparedness for NPP 24hr Emergency Response Program Maintenance of REMP system with NPP appointed hospitals Education/ Training Program WHO/REMPAN Liaison Institute -Primary H. Secondary H. * REMP : Radiation Emergency Medical Preparedness
Accidental dose evaluation system Decision-making for the treatment of patient caused by radiation exposure Biological Assessment Clinical Evaluation CA, FISH, MN, PCC Clinic symptoms Radiation Dose Assessment Physical Assessment Mathematical Assessment ESR, WBC, LSC Body Activation Analysis MCNP, VOXEL
Tooth Ring Watch C.P. Sugar Ceramics Quartz • Electron Spin Resonance System Spectrum in teeth Dose response curve
線量評價 血液分析 照射 模寫 KBADA MCNP-X Modified BOMAB : 製作 • Body Activation Analysis System Neutron spectrum : Excel 開發 HPGe AAS NPP BSS Dose assessment S/W:Visual Basic 開發 Water Slab Phantom : 製作
Study on internal dosimetry Fast Scan MCNP CRM 改善 Inter-Comparison Accu-Scan HPGe Technical support about Internal dosimetry for NPPs in Korea Measurement system 構築 Korean Phantom 開發 Guide Guideline Training of NPP members IDEAS Guideline Guide S/W 開發 Wound model
Radiation dose reconstruction, PC calculation & • epidemiologic investigation Program for Estimating Probability of Causation
Application study of ICRP new recommendation 2011(?) (?)
Thank You ! Korea Hydro & Nuclear Power Co., LTD Radiation Health Research Institute