Presenter_On-Site_00 1 Radiation Protection Fundamentals Craig Maxwell - RCT Radiation Protection Group Lawrence Berkeley National Laboratory

Presenter_On-Site_00 2 Objectives Familiarize you with some of the basics of Radiation and Radioactive Decay Discuss some of the common instruments found in research labs Review control methods used to reduce exposure

Presenter_On-Site_ Nucleus Neutrons Protons Electrons (Electron Clouds) Structure of the Atom

Presenter_On-Site_00 4 Ionizing radiation High energy radiation Gamma-rays, x-rays - photons Particles: alpha, beta, neutron Ejects electrons from atoms Produces an altered atom - an ion Non-ionizing radiation Low energy Lasers, RF, microwaves, IR, visible Excites electrons Produces heat

Presenter_On-Site_00 5 Alpha Decay 4 He Nucleus Ejected from Nucleus Your skin will stop it internal hazard stopped by paper found in soil, radon and other radioactive materials

Presenter_On-Site_00 6 Beta Decay Either too many neutrons or too many protons stopped by plastic skin, eye and internal hazard Naturally occurring in food, air and water

Presenter_On-Site_00 7 Gamma / X-ray Decay Emission of a photon Often occurs after  or  when nucleus is in an excited state stopped by lead medical uses naturally present in soil and cosmic radiation

Presenter_On-Site_00 8 Types of Ionizing Radiation Alpha Beta Gamma and X-rays Neutron PaperPlasticLeadConcrete Helium nucleus (2 protons, 2 neutrons): +2 charge Electron: +1 or -1 charge Photon: 0 charge Neutron: 0 charge

Presenter_On-Site_00 9 Radiation Quantities and Units Radioactivity Qty: Activity Unit: Curie (Bequerel) 1 Ci = 1000 mCi 1 Bq = 1 dis per sec 1 Ci = 3.7 e10 Bq Radiation Risk Qty: Dose Equivalent Unit: rem (Sievert) 1 rem = 1000 mrem 1 Sv=100 rem Radiation Absorbed Dose Qty: Dose Unit: rad (Gray) 1 rad mrad 1 rad = 100 erg/gram 1 Gy=100 rad roentgen equivalent man

Presenter_On-Site_00 10 Radiation Weighting Factors (W R ) Absorbed dose (Rad/Gy) x W R = Equivalent dose (rem) Photons, electrons & muons (all energies) 1 Beta & positron 1 Neutrons 5-20 Alpha, fission fragments, heavy nuclei 20 10CFR835

Presenter_On-Site_00 11 Sources of Ionizing Radiation Radioactive materials Naturally occurring (uranium, carbon-14, …) Artificial (activated by neutrons from a reactor or accelerator beam) Radiation Producing Machines X-ray machines (characteristic, bremstrahlung) Accelerators (ion beams, neutrons, x-rays)

Presenter_On-Site_00 12 Background and Manufactured Radiation In the U.S. Contributes 360 mrem per year

Presenter_On-Site_00 13 Manufactured Sources of Radiation Cigarette Smoking mrem Building Materials mrem Fallout < 1 Smoke Detectors Medical – 53 mrem mrem Medical Doses: A: Dental exam (16 mrem) B: Mammogram (25 mrem) C: Tc-99m cardiac function (75 mrem) D: Cranial CT multiple scans (up to 5 rem) E: “Full body CT screening” – one scan ( 1 to 2 rem) F: Spiral whole body CT scan ( 3 to 10 rem)

Presenter_On-Site_00 14 Whole Body Annual Dose Limits RADIATION WORKER - Federal NRC Limits Whole Body mrem/year Extremities - 50,000 mrem/year Skin - 50,000 mrem/year Eyes mrem/year Pregnant mrem/term / 50 mrem/month General Pubic mrem/year

Presenter_On-Site_00 15 Effect of Dose and Dose Rate 100 rems 20 years 5 min Chronic exposures may increase cancer risk. 100,000 people exposed to 100 mREM 4 or 5 additional cancers Localized effects: >500 REM Skin – radiation burn Whole body effects: LD 50/ RAD

Presenter_On-Site_00 16 Risk Perspective Average Estimated Days Lost Due to Daily Activities Health RiskAve. Est. Days Lost Unmarried Male3,500 Cigarette Smoking2,250 Unmarried Female1,600 Coal Miner1,100 25% Overweight 777 Alcohol (U.S. average) 365 Construction Worker 227 Driving a Motor Vehicle mrem/year for 70 years 10

Presenter_On-Site_00 17 Radiation vs Contamination

Presenter_On-Site_00 18 Radiation Vs. Radioactive Contamination Radiation is particles or waves of energy emitted from unstable atoms. Radioactive Contamination is radioactive material usually in any location you do not want it. Exposing a material to radiation does not necessarily make it radioactive, but radioactive material on a non-radioactive item, makes the item contaminated.

Presenter_On-Site_00 19 Radiation Survey Meters Two common Ion Chamber radiation survey instruments are: Victoreen Bicron

Presenter_On-Site_00 20 Beta Contamination Instrument Ludlum 3 Type: Normally equipped with a Geiger- Mueller 44-9 (pancake) probe Detects: Beta, gamma

Presenter_On-Site_00 21 Alpha/Beta Contamination Instrument Ludlum 2224 Type: Plastic scintillation for beta detection that has a [ZnS (Ag)] coating for alpha detection Detects: Alpha and Beta

Presenter_On-Site_00 22 Other Instrumentation Ludlum 16 with a 44-3 thin window NaI probe Liquid Scintillation (LSC)

Presenter_On-Site_00 23 Instrument performance Dead or low batteries - erratic or no detection Calibration has changed - may read high or low Defective cable or other problems Poor survey technique – angle of probe to source - only detects part – to far from source - radiation absorbed by air – survey too fast – only detects part You must use them correctly if you expect them to work for you

Presenter_On-Site_00 24 Radiation & Contamination Control Methods Used to reduce exposure to radiation and radioactive material contamination

Presenter_On-Site_00 25 Engineering Controls Containment –Glove box –Glove bag Ventilation – Fume Hood – Bio Safety Cabinet

Presenter_On-Site_00 26 Engineering Controls cont. Interlocks Tamper-Proof Screws/Bolts Flange Padlocks Security Seals Shielding Access controls (e.g. card key)

Presenter_On-Site_00 27 Administrative Controls Regulations Formal Authorizations Facility policies and procedures Labels, signs, and postings Routine radiation surveys Machine operational restrictions

Presenter_On-Site_00 28 ALARA As Low As Reasonably Achievable ALARA Techniques: Time - (Reduce) Distance – (Increase) Shielding – (Proper Shielding) Reduce Radiation Doses

Presenter_On-Site_00 29 Control Methods Engineering Administrative ALARA Techniques Time Distance Shielding Missing Control

Presenter_On-Site_00 30 Exposure Prevention Methods Protective clothing such as lab coats, gloves & safety glasses Self-monitoring to reduce the spread of radioactive contamination

Presenter_On-Site_00 31 Good Work Practices Use deliberate movements and apply lessons learned from cold runs (mock-ups).

Presenter_On-Site_00 32 Respect and Understand the Postings Treat all radiological areas as if everything was contaminated.

Presenter_On-Site_00 33 Common sources of radioactive contamination –Sloppy work practices –Poor housekeeping –Opening radioactive materials/systems without proper controls –Leak or tears in containers –Damaged Sealed Sources –Spills

Presenter_On-Site_00 34 Upon Completion of Work Be sure to survey yourself

Presenter_On-Site_00 35 Upon Completion of Work Hand washing is a good work practice and an important final step after working with any radioactive material.

Presenter_On-Site_00 36 Final Thoughts It is our mission to ensure that research and learning continue in the safest manner possible. Be a mentor Be a resource Lead by example Always use best practices