Radiation and Laser Safety Mike McGuigan Radiation Safety Officer, Environment, Safety, Health and Assurance Ames Laboratory

Safety Standards/Regulations Nuclear Regulatory Commission. Iowa Department of Public Health (Iowa Administrative Code)  Iowa State University Department of Energy (10 CFR 835)  Ames Laboratory US DOE

Topics for Today Radiation Fundamentals Radiation Protection Laser Safety Laser Protection

Radiation Fundamentals Atomic Structure  The basic unit of matter is the atom.  The three basic particles of the atom:  protons,  neutrons, and  electrons.  The central portion of the atom is the nucleus  The nucleus consists of protons and neutrons.  Electrons orbit the nucleus.

Radiation Fundamentals Radiation and Ionizing Radiation Radiation is energy that moves through space. Examples of radiation include light, sound, radio waves, and X-rays. Ionizing radiation is radiation that can cause ionization of the material it passes through. That is, it removes electrons from atoms as it moves through matter.

Radiation Fundamentals Types of Radiation

Radiation Fundamentals Ionizing Radiation

Types of Radiation Alpha          Beta Gamma and X-rays Neutron PaperPlastic Lead Concrete 10n10n

Dose Units Roentgen ( R ): a measure of exposure rad (absorbed dose) = 100 ergs/gram rem (dose equivalent) = rad x Q Q is the quality factor Q = 1 for  &  radiation Q = 20 for  radiation 1 gray = 100 rad 1 sievert = 100 rem

Radiation Fundamentals Sources of Background Radiation

Radiation Protection ALARA Concept ALARA stands for As Low As Reasonably Achievable. Because some risk, however small, exists from any radiation dose, all doses should be kept ALARA. Includes reducing both internal and external radiation dose. ALARA is the responsibility of all employees.

How do I protect myself and keep my dose ALARA? Hierarchy of Controls:  used for External and Internal Radiation Dose Reduction 1. Engineering controls- primary method to control exposure (e.g., enclosed hoods). 2. Administrative controls- next method to control exposures (e.g., postings). 3. Personnel Protective Equipment- last method (e.g., respirators).

External Radiation Protection Techniques Basic protective measures used to minimize external dose include  Minimizing time in radiation areas  Maximizing the distance from a source of radiation  Using shielding whenever possible  Reducing the amount of radioactive material (source reduction)

Radiation Protection Minimize Time

Maximize Distance (Intensity decreases as 1/dist 2 )

Use Shielding

Internal Radiation Protection Techniques  Internal hazards require Contamination Control  Always Use PPE - especially GLOVES when working with radioactive materials!!!

Administrative Controls  Follow Standard Operating Procedures (SOP)  Practice procedure without RAM  Employ Spill control measures  Monitor continually

Administrative Controls Designate a specific laboratory area for use of radioactive materials Wear Protective Clothing (Lab Coats, Double Gloves, Safety Glasses)

Administrative Control Limits DOE Dose Equivalent Limit rem/y IDPH Dose Limits rem/y Whole body55 Extremity50 Skin and other organs50 Lens of the eye15 Member of the public and minors 0.1 Declared pregnant worker 0.5/gestation period

Engineering Controls

Radiation Producing Devices Radiation Producing Equipment: Do not bypass safety interlocks!!!

Example of Radiation Damage Erythema Of Right Hand 4 th Day, 17 th Day, 3 ½ Months, Five Months, Seven Months After Accident

Laser Safety

Safety Standards  The Federal Laser Product Performance Standard (FLPPS) of the Center for Devices and Radiological Health (CDRH) This is federal law and applies to the manufacture of lasers.  The American National Standard for Safe Use of Lasers (ANSI Z136.1) Recognized by: The Occupational Safety and Health Administration (OSHA)  IEC International Standard  IowaStateUniversityLaserSafetyManual (

Definition - LASER L ight A mplification by S timulated E mission of R adiation

Properties of Laser Monochromatic Highly directional Coherent

Laser Hazards Eye : Acute exposure of the eye to lasers of certain wavelengths and power can cause corneal or retinal burns (or both). Chronic exposure to excessive levels may cause corneal or cataracts or retinal injury. Skin : Acute exposure to high levels of optical radiation may cause skin burns; while carcinogenesis may occur for ultraviolet wavelengths ( nm). Chemical : Some lasers require hazardous or toxic substances to operate (i.e., chemical dye, Excimer lasers). Electrical : Most lasers utilize high voltages that can be lethal. Fire : The solvents used in dye lasers are flammable. High voltage pulse or flash lamps may cause ignition. Flammable materials may be ignited by direct beams or specular reflections from high power continuous wave (CW) infrared lasers.

LASER Classes and Signs  Class 1  Class 1M  Class 2  Class 2M  Class 3R  Class 3B  Class 4

Laser Hazard Classification Scheme for ANSI Z136.1 Standard  Class 1 & 1M (Exempt)  Incapable of producing damaging radiation levels  Class 2 & 2M (Low power)  visible light ( nm)  Protection is aversion response  Powers <1mW

Laser Hazard Classification Scheme for ANSI Z136.1 Standard  Class 3 (Medium Power)  Two subclasses 3R & 3B  Hazardous under direct and specular reflection viewing  Visible laser that can produce spot blindness  CW upper limit is 0.5 W

Laser Hazard Classification Scheme for ANSI Z136.1 Standard  Class 4 (High Power)  Hazardous to the eye if beam is viewed directly (Class 3b & 4) and indirectly (Class 4 only)  Skin burns likely with Class 4 laser  Generation of air contaminants

What will you encounter at ISU and Ames Laboratory?  Many types  Laser pointers to Eximer Lasers  ISU/Ames Lab have about 200+ Class 3B and Class 4 lasers or laser systems.

Hazard Control Priorities 1. SUBSTITUTION - Less hazardous equipment / process 2. ENGINEERING CONTROLS - Shields, interlocks,.. 3. ADMINISTRATIVE CONTROLS - Rules, procedures,.. 4. PERSONAL PROTECTIVE EQUIPMENT – Eyewear, …

Engineering Controls Class 3B and Class 4 Interlocks  Door  Shutters Beam Enclosures Beam Stops MOST IMPORTANT SAFETY CONTROLS

Administrative Controls  Laser Hazard Assessment for class 3B and 4  Written Procedures  Normal Operations  Maintenance and Aligning Procedures  Emergency Response  Signage  Authorized User List  Laser Safety Training  Medical Examination  Base-Line and Exit

Personal Protective Equipment  Laser Goggles  Wavelength and Optical Density  Other Items  Lab Coat, Gloves  Appropriate Ventilation  Lockout / Tag out

Common Safety Items to Remember  Observe/Obey Signs and Postings  Wear Correct and Undamaged Laser Goggles  Follow Procedures  Operating, Maintenance, and Emergency  Ensure Proper Interlock Operation  Use Beam Enclosures When Required  Call Safety Office for a Laser Hazard Assessment if working with 3b or 4 laser

Laboratory Accidents Laser accidents within DOE - Brookhaven National Lab (2) - Los Alamos National Lab - Argonne National Lab (2) - National Renewable Energy Lab - Lawrence Berkeley National Lab X-ray interlocks bypassed.

Bypassing X-ray System Interlocks

Same hand days later

Days later

Iowa State University Eric Armstrong, LSO Stephen Simpson, RSO Ames Laboratory Jim Withers, LSO Michael McGuigan, RSO On-Line Laser Safety Manual on ISU EHS webpage