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

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 FundamentalsTypes of Radiation

<-Ionizing Radiation->

Radiation Fundamentals Ionizing Radiation

Types of Radiation

Alpha

Beta

Gamma and X-rays

Neutron

Paper Plastic Lead Concrete

10n

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 FundamentalsSources of Background Radiation

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)

Radiation Protection Minimize Time

Maximize Distance(Intensity decreases as 1/dist2)

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 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

Engineering Controls

Engineering Controls

Radiation Producing Devices

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

Example of Radiation Damage

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

Laser Safety

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 60825 International Standard

IowaStateUniversityLaserSafetyManual (http://www.ehs.iastate.edu/publications/manuals/lsm.pdf)

Definition - LASER

• Light • Amplification by• Stimulated• Emission of• Radiation

Properties of Laser

Monochromatic

Highly directional

Coherent

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 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 (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.

Bypassing X-ray System Interlocks

Same hand days later

Days later

Iowa State University• Eric Armstrong, LSO • Stephen Simpson, RSO• 294-5359

Ames Laboratory• Jim Withers, LSO• Michael McGuigan, RSO• 294-2153

On-Line Laser Safety Manual on

ISU EHS webpage