radiation and laser safety mike mcguigan radiation safety officer, environment, safety, health and...
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Radiation and Laser Safety
Mike McGuiganRadiation 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
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.
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 ProtectionALARA 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)
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 body 5 5
Extremity 50 50
Skin and other organs 50 50
Lens of the eye 15 15
Member of the public and minors
0.1 0.1
Declared pregnant worker
0.5/gestation period 0.5/gestation period
Example of Radiation Damage
Erythema Of Right Hand 4th Day , 17th Day, 3 ½ Months , Five Months , Seven Months After Accident
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 60825 International Standard
IowaStateUniversityLaserSafetyManual (http://www.ehs.iastate.edu/publications/manuals/lsm.pdf)
Laser Hazards
Eye Eye : Acute exposure of the eye to lasers of certain wavelengths : Acute exposure of the eye to lasers of certain wavelengths and power can cause corneal or retinal burns (or both). and power can cause corneal or retinal burns (or both). Chronic exposure to excessive levels may cause corneal or Chronic exposure to excessive levels may cause corneal or cataracts or retinal injury.cataracts or retinal injury.
SkinSkin : Acute exposure to high levels of optical radiation may : Acute exposure to high levels of optical radiation may cause skin burns; while carcinogenesis may occur for cause skin burns; while carcinogenesis may occur for ultraviolet wavelengths (290-320 nm).ultraviolet wavelengths (290-320 nm).
Chemical Chemical : Some lasers require hazardous or toxic substances : Some lasers require hazardous or toxic substances to operate (i.e., chemical dye, Excimer lasers).to operate (i.e., chemical dye, Excimer lasers).
Electrical Electrical : Most lasers utilize high voltages that can be lethal.: Most lasers utilize high voltages that can be lethal.FireFire : The solvents used in dye lasers are flammable. High : The solvents used in dye lasers are flammable. High
voltage pulse or flash lamps may cause ignition. Flammable voltage pulse or flash lamps may cause ignition. Flammable materials may be ignited by direct beams or specular materials may be ignited by direct beams or specular reflections from high power continuous wave (CW) infrared reflections from high power continuous wave (CW) infrared lasers.lasers.
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 (400-700nm) 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 ControlsClass 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.