1. 1 Radiological protection, dosimetry & environmental monitoring National Training Course on Radiopharmacy, Radiochemistry and Radioisotope Production Site Management Dr. Radu Vasilache Canberra Packard

2. IAEA TC project ROM/6/017 2 Overview 1. Quantities and standards 2. What to survey? Pathways of exposure 3. Radiation protection planning 4. Specific instruments and methods for radiation monitoring 5. Conclusions

3. IAEA TC project ROM/6/017 3 Standards and regulations  Law 11/1996 & Basic Radiological Protection Norms  Set up the dose limits for exposed personnel (20 mSv/year) and population (1 mSv/year)  IAEA Basic Safety Standards

4. IAEA TC project ROM/6/017 4 Quantities to be measured / calculated  Doses:  Absorbed dose D = dE/dm, measured in Gy (1 Gy = 1 J/kg)  Equivalent doses (used in practice for external radiation, measured): Personal equivalent dose (penetrating) H p (10), measured in Sv (1 Sv = 1 Gy for photons), for personnel monitoring Ambient equivalent dose H*(10), measured in Sv, for area monitoring  Effective committed doses (used in practice for internal exposure, calculated): the dose that an individual will receive over a number of year, resulting from the intake of radiaoctive substances

5. IAEA TC project ROM/6/017 5 Quantities to be measured  Activity (measured in Bq):  External contamination of equipment & personnel  Internal contamination (WBC)  Effluents (gaseous & liquid)  Waste

6. IAEA TC project ROM/6/017 6 Radiation protection planing Steps for building up a proper RP management plan: 1. Identify all possible pathways / sources of exposure specific to the site (e.g.: external exposure at the cyclotron site, in the hot-rooms, etc., internal exposure possibilities, ways of discharging effluents, etc.) 2. Identify all possible accidents via a fail chart, set up emergency response plan 3. Identify points of continuous monitoring and what needs monitored

7. IAEA TC project ROM/6/017 7 What to survey? Survey targets in a cyclotron production site & paths of exposure:  Protection of the working personnel:  Direct exposure to external radiation – dose monitoring  Internal exposure through inhalation & ingestion – internal contamination (activity) monitoring, doses are calculated  External contamination  Protection of the public  Gaseous effluents  Liquid effluents  Waste disposal

8. IAEA TC project ROM/6/017 8 Dosimetry – personnel monitoring  Quantities to be measured:  H p (10) – personal equivalent dose, penetrating: doses due to external penetrating radiation (above 60 keV), the point of interest is considered as 10 mm below the surface of the skin  H p (0.07) – personal dose equivalent, superficial: doses to to low energy external radiation (photons below 60 keV, beta radiation)  Instruments:  Electronic alarm dosemeters  Film dosemeters  TLDs  Glass dosemeters

9. IAEA TC project ROM/6/017 9 Examples of personnel dosemeters

10. IAEA TC project ROM/6/017 10 Personnel dosimetry – internal contamination  Whole Body Counting  Spectroscopic measurement of intake  Measures the activity and calculates committed dose per radionuclide  Adds up to the external dose

11. IAEA TC project ROM/6/017 11 Personnel contamination

12. IAEA TC project ROM/6/017 12 Dosimetry – area monitoring  Ambient equivalent dose H*(10)  Measured directly, usualy the dose, time stamp and location are logged in  Usually applies to photons (gamma & X) and neutrons  Area monitoring normally involves network monitoring, with detectors sending remotely the data, combined with periodic surveys performed by operators

13. IAEA TC project ROM/6/017 13 Dosimetry for area monitoring - examples

14. IAEA TC project ROM/6/017 14 Area monitoring – hand held units

15. IAEA TC project ROM/6/017 15 Details to be observed  Dose ranges: in areas where the dose rate could have significant fluctuations, a matter of concern should be the saturation of the probes  TTC methods is the answer

16. IAEA TC project ROM/6/017 16 Time – to – count principle Conventional GM Tube Operation TIME PULSE DISCR. WAVE FORMS +HV BIAS

17. IAEA TC project ROM/6/017 17 Time – to – count principle “Time to Count” Operation HV 2 t on t off GM TUBE WAVEFORMS TIME Time Totalizer Pulse Totalizer ÷ Average Time to Count RATE = K TIME TO COUNT

18. IAEA TC project ROM/6/017 18 Time – to – count principle “Time to Count” Behaviour HV +HV 2 SHORT TIME 2 mSec. TIME HIGH FIELD HV +HV 2LONG TIME 2 mSec. TIME LOW FIELD

19. IAEA TC project ROM/6/017 19 Effluent & waste monitoring  Should be integrated in the same RMS software as the dose area monitoring  Involves gas & liquid discharges  Waste (solid & liquid) are to be measured and categorised according to the activity  Can be done via radiometric and / or spectrometric measurements  The architectures of GEM & LEM are similar

20. IAEA TC project ROM/6/017 20 Gaseous and liquid effluent monitors

21. IAEA TC project ROM/6/017 21 Gaseous Effluent Monitor SPING CP/GNS/SCN-1  Two monitors (reactor hall and stack), with 3 channels each – MGN (noble gas), MIR (iodine), MAR (aerosol)  Each channel has a NaI 3x3 inch with UniSpec (can be replaced with any other combination of detector & MCA)  New architectures can combine stabilised NaI or LaBr with Osprey, or HPGe coaxial detectors with electrical cooling and Lynx MCA, thus making totally useless the usage of local computing stations  Result of the combined work of CPRO, GNS and SCN Pitesti

22. IAEA TC project ROM/6/017 22 Gaseous effluent monitor (cont.)

23. IAEA TC project ROM/6/017 23 Control software

24. IAEA TC project ROM/6/017 24 Gaseous effluent monitors – non spectrometric

25. IAEA TC project ROM/6/017 25 Liquid effluent monitors  On-line / in-line

26. IAEA TC project ROM/6/017 26 Waste assay & objects contamination monitors  Radiometric / spectrometric

27. IAEA TC project ROM/6/017 27 Conclusions  From the point of view of the radiological protection, one must observe the following in the site planing:  Plan for the possible incidents and the pathways of exposure  Insure proper monitoring of personnel exposure / contamination  Monitor the environmental releases and keep them under control (limit population exposure)  Monitor waste production  Decide for the best technological solution applicable to the site to achieve the above objectives

28. IAEA TC project ROM/6/017 28 Mulumesc! Întrebări?