1 / 87

RADIATION SAFETY T RAINING

RADIATION SAFETY T RAINING. Presented by: Ali Shoushtarian Office of Risk Management, Environmental Health and Safety Service. Last revised Jan. 2007. Manager, Radiation and Biosafety Lois Sowden-Plunkett ext. 3058 lsowden@uottawa.ca Compliance Inspector

matana
Télécharger la présentation

RADIATION SAFETY T RAINING

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. RADIATIONSAFETYTRAINING Presented by:Ali Shoushtarian Office of Risk Management, Environmental Health and Safety Service Last revised Jan. 2007

  2. Manager, Radiation and Biosafety Lois Sowden-Plunkett ext. 3058 lsowden@uottawa.ca Compliance Inspector Ali Shoushtarian ext. 3057 ashousht@uottawa.ca Radiation Safety Program Web Page http://www.uottawa.ca/services/ehss/ionizing.htm

  3. REGULATORY AGENCIES • Canadian Nuclear Safety Commission (CNSC) • City of Ottawa • Ontario Fire Marshall • Transport Canada • Ontario Ministry of Labour

  4. Radiation Safety Committee Reports to the Board of Governors Chaired by Vice-Rector, Research Ensures compliance with CNSC regulations and license conditions, issues permits Office of Risk Management – EHS Manages the radiation safety program Conducts inspections Monitors doses, inventory Conducts training STAKEHOLDERS

  5. STAKEHOLDERS Radioisotope Permit Holder • Ensures all University regulations, policies and requirements are met • Adheres to all permit limits and conditions • Ensures a safe work environment Radioisotope User • Complies with all elements of radiation safety program • Works in a safe fashion (self, colleagues, environment) • attends all appropriate training

  6. PERMITS 1. Open Sources 2. Sealed Sources 3. Sealed Sources incorporated in a device 4. Exempt Quantities with associated permit conditions

  7. COURSE OUTLINE GENERAL INTRODUCTION physical and biological characteristics risk analysis units and calculations OPERATIONAL PROCEDURES ordering and receipt of material inventory and disposal monitoring SAFE PRACTICES personal protection handling procedures laboratory safety MOVIE

  8. WHAT IS RADIATION ? WHAT IS RADIATION ?

  9. RADIATION • Spontaneous decay • Half-life • 4 geometry

  10. RADIATION Excess p & n  alpha particles Excess p  positron ( + ) Excess n  negatron (  - ) Excess nuclear E  gamma ray Excess orbital E  X-ray

  11. ALPHA EMISSION • origin: DISINTEGRATING NUCLEUS (Mainly heavy nuclei) • form of radiation: PARTICLE • energy range: 4-8 MeV • range of travel: 2-8 cm in air • other characteristics: LARGE MASS, DOUBLE CHARGE, HIGH SPECIFIC ACTIVITY

  12. BETA EMISSION • origin: DISINTEGRATING NUCLEUS • form of radiation: NEGATRON (electron) POSITRON (similar to an electron but positive charge) • energy range: 0.02 - 4.8 MeV • range of travel: 0 - 10 m in air • other characteristics: DIFFERS FROM AN ELECTON IN ORIGIN AND ENERGY; TRAVELS ALMOST THE SPEED OF LIGHT; ALMOST NO MASS (9.1x 10-31 kg)

  13. GAMMA EMISSION • origin: NUCLEUS • form of radiation: ELECTROMAGNETIC RADIATION (emr - photon) • energy range: 10 keV - 3 MeV • range of travel: 100 m in air • other characteristics: ZERO MASS, ELECTRICALLY NEUTRAL

  14. X-RAY EMISSION • origin: ORBITAL ELECTRON • form of radiation: ELECTROMAGNETIC RADIATION (emr - photon) • energy range: 10eV - 120 keV • range of travel: 100 m in air • other characteristics: ZERO MASS, ELECTRICALLY NEUTRAL

  15. INTERACTION WITH MATTER IONIZATION • Electron is removed from an electron shell leaving a charged particle. EXCITATION • Electron is raised to a higher energy level but isn’t knocked out of the shell

  16. BREMSSTRAHLUNG • A negatron approaches the nucleus and is accelerated. • As it leaves the nucleus it decelerates and emits excess energy as emr. INTERACTION WITH MATTER

  17. DIRECT vital cell structures INDIRECT ionizes H2O forms peroxides interacts with the vital cell structure INTERACTION WITH BIOLOGICAL MATTER

  18. RADIATION RANGES IN TISSUE (average linear dimension of a cell = 17.1 m ) • alpha particles of 210Po ……… 15m • beta particles of 3H …………… 5 m • beta particles of 32P ……….. 300 m • gamma rays of 60Co …………. infinity

  19. RADIOSENSITIVITY OF CELLS • Blood producing and reproductive cells are the most sensitive • Muscle, nerve and bone cells are the least. At low doses, the effects of radiation are not known.

  20. INTERNAL DOSES • CRITICAL ORGANS • 3H – Body water or tissue • 14C – Fat tissue • 32P – Bones • 35S – Gonads • 125I – Thyroid • 57Co – Large Intestine PREGNANCY

  21. EXTERNAL DOSES Gamma rays Beta particles Alpha particles

  22. BIOLOGICAL RESPONSE TO RADIATION • No change • Mutation and repair • Permanent change with limited effect • Changes leading to cancer or other effects • Death of cell / organism (minutes - years)

  23. THE EFFECTS OF RADIATION ON THE HUMAN BODY • Genetic • appears in latter generations • due to cell damage of the reproductive organs • Somatic • appears in the irradiated individual • immediate or delayed effects • Stochastic • refers to probability of biological effect due to ionizing radiation • assumes effect is proportional to dose / dose rate, i.e., no safe threshold

  24. non-NEWNEW Whole body, gonads, 1 mSv 50 mSv bone marrow Skin, thyroid, bone 50 mSv 500 mSv Tissue of hands, feet, 50 mSv 500 mSv and forearms Dose Limits: THERMOLUMINESCENT DOSIMETRY

  25. COMPARISON OF RISK • exposure to 100 Sv ionizing radiation • smoking 1.5 cigarettes • travelling 50 miles by car • being male and 60 years old for 20 minutes • canoeing for 6 minutes

  26. UNITS OF RADIATION • ACTIVITY • ABSORBED DOSE • DOSE EQUIVALENT

  27. ACTIVITY UNITS Non - S.I.(Système international) CURIE (Ci) 1 Ci = 3.7 x 1010 dps S.I. BECQUEREL (Bq) 1 Bq = 1 dps

  28. ABSORBED DOSE UNITS Non - S.I. RAD (rad) 1 rad = 100 ergs of energy/g S.I. GRAY (Gy) 1 Gy = 1 joule of energy/kg

  29. DOSE EQUIVALENT UNITS Non - S.I. REM (rem) 1 rem = rad x Quality Factor S.I. SIEVERT (Sv) 1 Sv = Gy x Quality Factor

  30. CALCULATIONS TWO IMPORTANT CALCULATIONS: 1. Decay correction 2. Converting cpm to Curies

  31. CALCULATIONS 1. DECAY CORRECTION A = Aoe -  t A = activity at time “t” Ao= activity at time zero t = elapsed time  = decay constant ( = 0.693 / t 1/2)

  32. CALCULATIONS Example: • 250 Ci of 35S arrived on May 19, 2005 • 100 Ci was removed and used the same day. • The remaining amount was stored in a freezer for future use. • On June 30, 2005, it is decided to repeat the experiment. ? Does another order of 35S have to be placed or is there enough remaining activity that the experiment may proceed?

  33. CALCULATIONS Solution: A = A0e - t A = activity at time ‘t’ ( ? ) A0= activity at time zero (250 - 100 = 150 Ci) t = elapsed time (42 days)  = decay constant (0.693 / 87 days = 0.00797) A = (150)e - (0.00797)(42) A = 107.32 Ci (** SAVINGS **)

  34. CALCULATIONS 2. CONVERTING CPM TO CURIES Step 1 Determine counting efficiency of the detector. Step 2 Convert cpm to dpm. Step 3 Convert dpm to Curie.

  35. CALCULATIONS Step 1 Determine counting efficiency of the detector using a source with a known activity. % efficiency = observed cpm - background cpm x 100 source of emission rate (dpm) Ex. count rate = 2045 cpm background = 65 cpm source = 220 Bq = 1.32 x 104 dpm % efficiency = 2045 - 65 cpm = 15% 1.32 x 104 dpm

  36. CALCULATIONS Step 2 Convert cpm to dpm. dpm = corrected cpm efficiency Ex. Sample = 4925 cpm background = 65 cpm efficiency = 15% dpm = 4925 - 65 = 32,400 0.15

  37. CALCULATIONS Step 3 Convert dpm to curie. Since 1 Bq = 1 dps = 2.7 x 10-11 Ci Then 60 dpm = 2.7 x 10-11 Ci Therefore32,400 dpm = 1.48 x 10-8 Ci or, # Bq = __1.48 x 10-8 Ci_ = 540 Bq 2.7 x 10 -11 Ci/Bq

  38. CLASSIFICATION OF LABORATORY Annual Limit on Intake (ALI) The activity, in Becquerel (Bq), of a radionuclide that will deliver an effective dose of 20 mSv after the radionuclide is taken into the body Basic: 5 X ALI Intermediate: 5-50 X ALI High: 50-500 X ALI Exemption Quantity (EQ) The quantity, in Becquerel (Bq), of a radionuclide, below which no licence is required 10000 EQ: Written approval from CNSC

  39. CLASSIFICATION OF RADIONUCLIDES • Contamination levels • Decommissioning levels Class A (high): Na-22, Zn-65 Class B (med): Rb-86 Class C (low): H-3, C-14 , S-35, Ca-45, P-33, P-32, I-125

  40. DECAY PRODUCTS 32P  Sulphur 14C  Nitrogen 35S  Chlorine 3H  Helium-3

  41. OPERATIONAL PROCEDURES • Ordering • Receipt of Radioactive Material (TDG) • Inventory • Disposal • Monitoring • Inspection of Laboratories

  42. ORDERING • Radioactive materials purchase procedures - Radioisotopes Purchase Requisition form - Form must be complete (PO number, signature) - EHSS approval before ordering - Documentation (packing slips, shipper’s declaration) • Permit conditions • Material purchased for other labs • Inventory records

  43. PURCHASE REQUISITION FORM

  44. RECEIPT OF RADIOACTIVE MATERIAL • TDG – Class 7 - Definition of radioactive materials - Radioactive packages - Radiation warning labels - Receipt of radioactive material

  45. TDG – CLASS 7 DEFINITION OF RADIOACTIVE MATERIAL FOR TRANSPORT Former: - 70kBq/kg New: - radionuclide dependent - types of radiation - energies - chemical forms - potentialbiological effect on persons

  46. TDG – CLASS 7 Radioactive packages may be shipped as: - Excepted packages - Industrial packages – Categories I, II and III - Type A packages – lower amounts - Type B (U) packages – large amounts; ≤ 700 kPa - Type B (M) packages – large amounts; > 700 kPa - Type C packages – for air transport of high activity

  47. TDG – CLASS 7 EXCEPTED PACKAGES - The safety mark ‘RADIOACTIVE’ must be visible on opening the package - The radiation level at any point on the external surface of the package must not exceed 5 Sv/h All other packages must be categorized by radiation level and display the corresponding radiation warning labels as follows:

  48. TDG – CLASS 7 RADIATION WARNING LABELS Category I-White: less than 5 Sv/h Category II-Yellow: less than 500 Sv/h, TI less than 1 Category III-Yellow: less than 2 mSv/h, TI less than 10 TI: maximum radiation level in Sv/h at 1 meter from the external surface of the package, divided by 10. Ex: 1 Sv/h (0.1 mrem/h) at 1 m equals a TI = 0.1

  49. TDG – CLASS 7 RECEIPT OF RADIOACTIVE MATERIAL - Radioactive packages must be delivered to the laboratory using a cart to increase distance between the transporter and the package in order to minimize radiation exposure - Inspect packaging both externally and internally for damage or leakage - Perform contamination monitoring on the package, vial holder and vial - Deface wording and labels prior to disposal of the package - Complete an Inventory of Use and Disposition form Report any anomalies to the supervisor and RSO

  50. INVENTORY • Sealed Sources (encapsulated, incorporated in a device, check sources) • Open Sources • Transfers ** HISTORICAL

More Related