Radiation Safety Program: Regulations and Practical Considerations for Safe Use of Radioactivity...

Radiation Safety Program: Regulations and Practical Considerations for Safe Use of Radioactivity

Radiation Safety Office

ETAS-239

501-569 8210

Graduate Institute of Technology, UALR

University of Arkansas at Little Rock

Ionizing and Non-ionizing radiation?• Radiation carries a range of energy forming an electromagnetic spectrum.

• Radiation that does not have enough energy to break chemical bonds but can vibrate atom is referred to as “Non-ionizing Radiations” e.g. radiowaves, microwaves, infrared, visible light etc.

• Radiation that has enough energy to break chemical bonds is referred to as 'ionizing radiation, e.g. alpha particles, beta particles, gamma rays etc.

Ionizing Radiation

How to know if there is a radiation source or radiation area- Symbols?

How to know if there is a radiation source or radiation area- Symbols?

“CAUTION RADIOACTIVE MATERIALS"

"CAUTION RADIATION AREA"

Radiation Package

Symbols

Radiation Protection Procedures

•External Radiation Protection

•Internal Radiation Protection

•Survey Procedures or Monitoring

•Radiation Spills

•Waste Disposal Guidelines

Radiation Dose Limit

ALARA is an acronym meaning As Low As Reasonably Achievable. It is a requirement of the agreement state (ADH) that all facilities possessing radioactive materials licenses to have a formal ALARA program. It is the policy of University of Arkansas at Little Rock to keep this exposure as low as reasonably achievable (ALARA).

A-L-A-R-A

General Handling Precautions

•Protective Clothing:

lab coats, gloves, masks, eye protection, sealing tapes etc

•The Work Place

Designate Clean area, Hood, Absorbent paper, drip trays, locks, no food items

•Manipulations of Radioactive Materials

plan ahead, pippetting, use minimum amounts, sealing tubes, reduce volatilization, proper monitoring, shielding, dosimeter, public perception

External Radiation Protection:

The Three Basic Rules

•Time: Dose = Dose Rate x Time

•Distance: The Inverse Square Law

ER2 = ER2 x (D1/D2)^2

•Shielding: Radiation EnergyShield DensityShield ThicknessBremsstrahlungHVL & TVLConcerns

Internal Radiation Protection

Mode of Entry into Body

Inhalation

Ingestion

Absorption

Injection

Individuals Requiring Radiation Safety Training

Three general categories of UALR employees with respect to their exposure to radiation:

• Radiation Workers: Those workers whose major responsibilities involve working with sources of ionizing radiation or radioactive material.

• Ancillary Workers: All personnel who may come in contact with or enter an area that contains radioactive material or sources of ionizing radiation e.g. janitorial staff.

• Non-Radiation Workers: personnel who would not normally be expected to encounter radioactive material or radiation sources in the course of their employment at UALR. This group does not require radiation training.

Radiation Safety Officer

501-569-8210

Assistant Radiation Safety Officer

501-569-8003

After Hours: Public Safety

501-569-3550

Also check “NRC Notice to Employees” posted in the radiation use and storage areas

Emergency Contacts

Part 1:Fundamentals of Laser Operation

Laser OutputContinuous Output (CW) Pulsed Output (P)

watt (W) - Unit of power or radiant flux (1 watt = 1 joule per second).

Joule (J) - A unit of energy

Energy (Q) The capacity for doing work. Energy content is commonly used to characterize the output from pulsed lasers and is generally expressed in Joules (J).

Irradiance (E) - Power per unit area, expressed in watts per square centimeter.

En

erg

y (W

atts

)

TimeE

ner

gy

(Jo

ule

s)Time

Types of Laser Hazards

1. 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 lenticular opacities (cataracts) or retinal injury.

2. Skin : Acute exposure to high levels of optical radiation may cause skin burns; while carcinogenesis may occur for ultraviolet wavelengths (290-320 nm).

3. Chemical : Some lasers require hazardous or toxic substances to operate (i.e., chemical dye, Excimer lasers).

4. Electrical : Most lasers utilize high voltages that can be lethal.

5. 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.

Lasers and Eyes • What are the effects of laser energy on the eye?

– Laser light in the visible to near infrared spectrum (i.e., 400 - 1400 nm) can cause damage to the retina resulting in scotoma (blind spot in the fovea). This wave band is also know as the "retinal hazard region".

– Laser light in the ultraviolet (290 - 400 nm) or far infrared (1400 - 10,600 nm) spectrum can cause damage to the cornea and/or to the lens.

• Photoacoustic retinal damage may be associated with an audible "pop" at the time of exposure. Visual disorientation due to retinal damage may not be apparent to the operator until considerable thermal damage has occurred.

MULTIPLE PULSE RETINAL INJURY

Laser-Professionals.com

Photo courtesy of U S Army Center for Health Promotion and Preventive Medicine

EYE INJURY BY Q-SWITCHED LASERRetinal Injury produced by four pulses from a Nd:YAG laser range finder.


Skin Hazards

• Exposure of the skin to high power laser beams (1 or more watts) can cause burns. At the under five watt level, the heat from the laser beam will cause a flinch reaction before any serious damage occurs. The sensation is similar to touching any hot object, you tend to pull your hand away or drop it before any major damage occurs.

• With higher power lasers, a burn can occur even though the flinch reaction may rapidly pull the affected skin out of the beam. These burns can be quite painful as the affected skin can be cooked, and forms a hard lesion that takes considerable time to heal.

• Ultraviolet laser wavelengths may also lead to skin carcinogenesis.

SKIN BURN FROM CO2 LASER EXPOSURE

Accidental exposure to partial reflection of 2000 W CO2 laser beamfrom metal surface during cutting


Other Hazards Associated with Lasers

Chemical Hazards Some materials used in lasers (i.e., excimer, dye and chemical lasers) may be hazardous and/or contain toxic substances. In addition, laser induced reactions can release hazardous particulate and gaseous products.(Fluorine gas tanks)

Electrical Hazards Lethal electrical hazards may bepresent in all lasers, particularly in high-power laser systems.

Secondary Hazards including: •cryogenic coolant hazards •excessive noise from very high energy lasers •X radiation from faulty high-voltage (>15kV) power supplies •explosions from faulty optical pumps and lamps •fire hazards

Laser ClassThe following criteria are used to classify lasers:

1. Wavelength. If the laser is designed to emit multiple wavelengths the classification is based on the most hazardous wavelength.

2. For continuous wave (CW) or repetitively pulsed lasers the average power output (Watts) and limiting exposure time inherent in the design are considered.

3. For pulsed lasers the total energy per pulse (Joule), pulse duration, pulse repetition frequency and emergent beam radiant exposure are considered.

CLASS 1 • Safe during normal use• Incapable of causing injury• Low power or enclosed beam

CLASS I Laser Product

Label not required

May be higher class duringmaintenance or service

Nd:YAG Laser MarkerLaser-Professionals.com

CLASS 2

CLASS II LASER PRODUCT

Laser RadiationDo Not Stare Into Beam

Helium Neon Laser1 milliwatt max/cw

• Staring into beam is eye hazard• Eye protected by aversion response• Visible lasers only• CW maximum power 1 mW

Laser Scanners


CLASS 3a

Small Beam

Expanded Beam

CLASS IIIa Laser Product

LASER RADIATION-AVOID DIRECT EYE EXPOSURE

ND:YAG 532nm5 milliwatts max/CW

• Aversion response may not provide adequate eye protection• CDRH includes visible lasers only• ANSI includes invisible lasers• CW maximum power (visible) 5 mW

Laser Pointers


CLASS IIIa LASER PRODUCT

Laser Radiation-Do Not Stare Into Beam or ViewDirectly With Optical InstrumentsHelium Neon Laser

5 milliwatt max/cw

CLASS 3b

• Direct exposure to beam is eye hazard• Visible or invisible• CW maximum power 500 mW

CLASS IIIb Laser Product

LASER RADIATION-AVOID DIRECT EXPOSURE TO BEAM

2 ND:YAG Wavelength: 532 nmOutput Power 80 mW

Courtesy of Sam’s Laser FAQ, www.repairfaq.org/sam/lasersam.htm, © 1994-2004

DPSS Laser with cover removed


CLASS 4

CLASS IV Laser Product

VISIBLE LASER RADIATION-AVOID EYE OR SKIN EXPOSURE TO DIRECT OR SCATTERED RADIATION

2 Nd:YAGWavelength: 532 nmOutput Power 20 W

• Exposure to direct beam and scattered light is eye and skin hazard• Visible or invisible• CW power >0.5 W• Fire hazard

Photo: Keith Hunt - www.keithhunt.co.ukCopyright: University of Sussex, Brighton (UK)Laser-Professionals.com

ANSI Classifications

•Class 1 denotes laser or laser systems that do not, under normal operating conditions, pose a hazard.

Class 2 denotes low-power visible lasers or laser system which, because of the normal human aversion response (i.e., blinking, eye movement, etc.), do not normally present a hazard, but may present some potential for hazard if viewed directly for extended periods of time (like many conventional light sources).

• Class 3a denotes some lasers or laser systems having a CAUTION label that normally would not injure the eye if viewed for only momentary periods (within the aversion response period) with the unaided eye, but may present a greater hazard if viewed using collecting optics. Class 3a lasers have DANGER labels and are capable of exceeding permissible exposure levels. If operated with care Class 3a lasers pose a low risk of injury.

• Class 3b denotes lasers or laser systems that can produce a hazard it viewed directly. This includes intrabeam viewing of specular reflections. Normally, Class 3b lasers will not produce a hazardous diffuse reflection.

• Class 4 denotes lasers and laser systems that produce a hazard not only from direct or specular reflections, but may also produce significant skin hazards as well as fire hazards.

ANSI Classifications (cont’d)

Reflection Hazards (cont’d)

Specular Reflection

Diffuse Reflection

CONTROL MEASURESEngineering Controls

Interlocks

Enclosed beam

Administrative Controls

Standard Operating Procedures (SOPs)

Training

Personnel Protective Equipment (PPE)

Eye protection

Common Laser Signs and Labels

http://images.google.com/imgres?imgurl=www.hsa.ie/osh/images/lasbeam.gif&imgrefurl=http://www.hsa.ie/osh/signsreg.htm&h=110&w=114&prev=/images%3Fq%3Dlaser%2Bsafety%2Bsigns%26start%3D100%26svnum%3D30%26hl%3Den%26safe%3Doff%26sa%3DN

LASER SAFETY EYEWEAR


LASER PROTECTIVE BARRIER

Photo courtesy of



The person operating the laser always has the primary

responsibility for all hazards associated with laser use.

WHO HAS PRIMARY RESPONSIBLITY FOR LASER SAFETY ANY TIME A CLASS 4 LASER IS OPERATED?

• Most beam injuries occur during alignment.

• Only trained personnel may align class 3B or

class 4 lasers (NO EXCEPTIONS!)

• Laser safety eyewear is required for class 3B and

class 4 beam alignment.

• ANSI REQUIRES approved, written alignment

procedures for ALL class 4 laser alignment

activities and recommends them for class 3B.

SAFE BEAM ALIGNMENT


Compressed gases present a unique hazard. Depending on the particular gas, there is a potential for simultaneous exposure to both mechanical and chemical hazards. Gases may be:

•Flammable or combustible •Explosive •Corrosive •Poisonous •Inert •or a combination of hazards

Return to Online Training

INTRODUCTION

http://www.pp.okstate.edu/ehs/MODULES/index.htm

Careful procedures are necessary for handling the various compressed gases, the cylinders containing the compressed gases, regulators or valves used to control gas flow, and the piping used to confine gases during flow.


INTRODUCTION


The contents of any compressed gas cylinder must be clearly identified. Such identification should be stenciled or stamped on the cylinder or a label. Commercially available three-part tag systems may also be used for identification and inventory.


IDENTIFICATION


Cylinders may be attached to a bench top, individually to the wall, placed in a holding cage, or have a non-tip base attached. Chains or sturdy straps may be used to secure them.


HANDLING & USE


Standard cylinder-valve outlet connections have been devised by the Compressed Gas Association (CGA) to prevent mixing of incompatible gases.

The outlet threads used vary in diameter; some are internal, some are external; some are right-handed, some are left-handed.

In general, right-handed threads are used for non-fuel and water-pumped gases, while left-handed threads are used for fuel and oil-pump gases.


HANDLING & USE


Cylinders should be placed with the valve accessible at all times. The main cylinder valve should be closed as soon as it is no longer necessary that it be open (i.e., it should never be left open when the equipment is unattended or not operating).

This is necessary not only for safety when the cylinder is under pressure, but also to prevent the corrosion and contamination resulting from diffusion of air and moisture into the cylinder after it has been emptied.


HANDLING & USE

Cylinders are equipped with either a hand wheel or stem valve. For cylinders equipped with a stem valve, the valve spindle key should remain on the stem while the cylinder is in service.

Only wrenches or tools provided by the cylinder supplier should be used to open or close a valve. At no time should pliers be used to open a cylinder valve.

Some valves may require washers; this should be checked before the regulator is fitted.


HANDLING & USE

Cylinder valves should be opened slowly. Oxygen cylinder valves should be opened all the way.

Open up the oxygen cylinder valve stem just a crack. Once the needle on the high pressure gauge has stopped, open up the valve all the way. This back-seats the valve.

Oxygen cylinders must have the valve opened up all the way because of the high pressure in the cylinder. There is a back-seating valve on the oxygen cylinder. This prevents the high-pressure gas from leaking out through the threaded stem.

When opening the valve on a cylinder containing an irritating or toxic gas, the user should position the cylinder with the valve pointing away from them and warn those working nearby.


HANDLING & USE

Cylinders containing flammable gases such as hydrogen or acetylene must not be stored in close proximity to open flames, areas where electrical sparks are generated, or where other sources of ignition may be present.

Cylinders containing acetylene shall never be stored on their side.


HANDLING & USE

Oxygen cylinders, full or empty, shall not be stored in the same vicinity as flammable gases.

The proper storage for oxygen cylinders requires that a minimum of 20 feet be maintained between flammable gas cylinders and oxygen cylinders or the storage areas be separated, at a minimum, by a fire wall five feet high with a fire rating of 0.5 hours.

Greasy and oily materials shall never be stored around oxygen; nor should oil or grease be applied to fittings.


HANDLING & USE

After the regulator is attached, the cylinder valve should be opened just enough to indicate pressure on the regulator gauge (no more than one full turn) and all the connections checked with a soap solution for leaks.

Never use oil or grease on the regulator of a cylinder valve.


HANDLING & USE

The following rules should always be followed in regards to piping:

Plastic piping shall not be used for any portion of a high pressure system.

Do not use cast iron pipe for chlorine.

Do not conceal distribution lines where a high concentration of a leaking hazardous gas can build up and cause an accident.

Copper piping shall not be used for acetylene.Return to Online Training

HANDLING & USE

A cylinder should never be emptied to a pressure lower than 172 kPa (25 psi/in2) (the residual contents may become contaminated if the valve is left open).

When work involving a compressed gas is completed, the cylinder must be turned off, and if possible, the lines bled.


HANDLING & USE

When the cylinder needs to be removed or is empty, all valves shall be closed, the system bled, and the regulator removed.

The valve cap shall be replaced, the cylinder clearly marked as "empty," and returned to a storage area for pickup by the supplier.

Empty and full cylinders should be stored in separate areas.


HANDLING & USE

Where the possibility of flow reversal exists, the cylinder discharge lines should be equipped with approved check valves to prevent inadvertent contamination of cylinders connected to a closed system.

"Sucking back" is particularly troublesome where gases are used as reactants in a closed system.

A cylinder in such a system should be shut off and removed from the system when the pressure remaining in the cylinder is at least 172 kPa (25 psi/in2).

If there is a possibility that the container has been contaminated, it should be so labeled and returned to the supplier.


HANDLING & USE

Liquid bulk cylinders may be used in laboratories where a high volume of gas is needed.

These cylinders usually have a number of valves on the top of the cylinder.

All valves should be clearly marked as to their function.

These cylinders will also vent their contents when a preset internal pressure is reached, therefore, they should be stored or placed in service where there is adequate ventilation.


HANDLING & USE

1. To protect the valve during transportation, the cover cap should be screwed on hand tight and remain on until the cylinder is in place and ready for use.

2. Cylinders should never be rolled or dragged.

3. When moving large cylinders, they should be strapped to a properly designed wheeled cart to ensure stability.

4. Only one cylinder should be handled (moved) at a time.


TRANSPORTATION OF CYLINDERS

Radiation Safety Program: Regulations and Practical Considerations for Safe Use of Radioactivity...

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