IAEA International Atomic Energy Agency Radiation Protection Issues in Nuclear Installations (NPP & RR) Laszlo Sagi Radiation Safety and Monitoring Section Division of Radiation, Transport and Waste Safety Department of Nuclear Safety and Security

IAEA Objectives Health risks for staff while visiting nuclear facilities −Nuclear power plants (NPPs) −Research reactors (RRs) Procedures to enter, stay in and exit controlled areas Practice and risk at Nuclear Installations

IAEA Outline Sources of radiation Measures to reduce risk −External radiation exposure −Internal radiation exposure Controlled areas −Definition −Boundaries −Entrance and exit −Instrumentation Practice and risk at Nuclear Installations

IAEA Nuclear Installations Research reactors −“Neutron factories” for training, research, materials testing or isotope production for medicine and industry −Currently around 240 facilities in 56 countries −Power: 100 kW th to 100 MW th in continuous operation −Inventory of fission products (10 MW th unit): Bq Nuclear power plants −For energy production −Power: 100 MW th to 2000 MW th −Inventory of fission products (1000 MW th unit): Bq Practice and risk at Nuclear Installations

IAEA Sources of Radiation Fuel in reactor core, spent fuel and core components Activation, fission and corrosion products Activated equipment, systems and piping Solid and liquid radioactive waste Gaseous radioactive material Experimental facilities generating activated or other radioactive material Tools and facilities for storage and handling of radioactive material Irradiated material Start-up neutron sources Neutron detectors (fission chambers, self-powered neutron detectors) Components of purification (filters and ion exchange columns) Practice and risk at Nuclear Installations

IAEA External Radiation Exposure Practice and risk at Nuclear Installations

IAEA Measures to Reduce Risk Basic principles to reduce radiation exposure and risk −Minimise the time of radiation exposure −Increase the distance from the source −Use appropriate material to provide shielding Time (t)→Distance (d)→Shielding (s) Practice and risk at Nuclear Installations

IAEA Internal Radiation Exposure No risk for intake of radionuclides by inhalation or ingestion during normal operation Risk for immersion Practice and risk at Nuclear Installations

IAEA Measures to Reduce Risk Basic measures to reduce internal radiation exposure −Do not smoke −Do not eat or drink −Do not apply cosmetics −Use personal protective equipment (gloves, overcoats, respirators, …) −Fit test before use Practice and risk at Nuclear Installations

IAEA Supervised and Controlled Areas Radiation areas are designated as to the maximum permissible effective dose rates 0.5 µSv/h3 µSv/h10 µSv/h 1 mSv/yr6 mSv/yr20 mSv/yr Free area Supervised area Controlled area PUBLICOCCUPATIONALLY EXPOSED WORKERS Practice and risk at Nuclear Installations

IAEA Protective Measures In controlled areas, specific protective measures or safety provisions are or could be required for −Preventing incorporation and the spread of contamination during normal working conditions −Preventing or limiting the extent of potential exposures Practice and risk at Nuclear Installations

IAEA Administrative Procedures Read and follow the local rules and procedures that are appropriate for controlled areas Practice and risk at Nuclear Installations

IAEA Boundaries of Controlled Areas Extent of controlled areas should be clearly defined Where practicable, the boundaries coincide with fixed barriers such as walls and doors of a room Registrants and licensees shall delineate controlled areas by physical means or, where this is not reasonably practicable, by some other suitable means Practice and risk at Nuclear Installations

IAEA Entrance to Controlled Areas Registrants and licensees shall provide, as appropriate, at entrances to controlled areas −Protective clothing and equipment −Individual and workplace monitoring equipment −Suitable storage for personal clothing Practice and risk at Nuclear Installations

IAEA Signs and Symbols Warning symbol and instructions at access points to : prohibit unauthorized access To use suitable PPE Symbols recommended by International Organization for Standardization (ISO) Practice and risk at Nuclear Installations

IAEA Instrumentation in Controlled Areas Fixed and portable radiation monitors Alarm system (acoustic and visual) Practice and risk at Nuclear Installations

IAEA Exit from Controlled Areas Monitoring equipment regarding contamination of skin, clothing and objects to be removed from area Washing or showering facilities Suitable storage for contaminated protective clothing and equipment Practice and risk at Nuclear Installations

IAEA Personnel Contamination Monitoring Monitoring : systematically and carefully stand straight on clean pad, feet spread slightly, arms extended, palms up and fingers straight out Monitor both hands and arms, then repeat with hands and arms turned over Monitor carefully forehead, nose, mouth, neckline, torso, knees and ankles; repeat on back of body Monitor soles of feet Practice and risk at Nuclear Installations

IAEA Barrier Procedures for Footwear Disciplined shoe change procedure is essential to contain contamination in designated area  Remove one overshoe before immediately swinging the shoeless foot over the barrier  Other foot may then be lifted to remove the second overshoe and again swinging the leg over the barrier without the shoeless foot touching the dirty area floor  Dirty overshoes may not leave the dirty area Practice and risk at Nuclear Installations

IAEA Conclusions Most facilities have their own radiological protection programmes, which are largely based on IAEA safety standards However, some facilities do not Practice and risk at Nuclear Installations

IAEA References Practice and risk at Nuclear Installations

IAEA International Atomic Energy Agency DISCUSSION What to do when…

IAEA Where to keep the personal dosimeter (TLD) during checking ? Hold luggage ? 1-2 mSv or Hand luggage ? µSv Quantities, exposures and Services23

IAEA Can we take the TLD to the medical inspection (e.g. X-ray check) ? Practice and risk at Nuclear Installations Please No ! The exposure 7- 8 mSv

IAEA What to do when your EPD beeps? Know what the alarm levels are (dose rate and dose). Walk away from the high dose rate area. (Increasing the distance reduces the dose rates at the occupied location). Make dose rate measurements (if you have a dose rate meter - Do not use your EPD!!!) Plan through the work, using time, distance and shielding. If applicable - share the work with a colleague Quantities, exposures and Services25

IAEA Am I protected from external radiation by external barriers? Cotton Gloves, Overalls, Boots, Shoe Covers, Vinyl Gloves Prevents contamination of skin Helps minimize spread of contamination Does not provide protection against external exposure Quantities, exposures and Services26

IAEA Thank you for your kind attention! Practice and risk at Nuclear Installations