Chapter 8 Flashcards
Most famous radiation incidents
- Hiroshima and Nagasaki- World war II, 1945.
- Chernobyl. - Former Soviet Union, 1984.
- •Madam Curie 1867 - 1934
- A Polish-French scientist worked with radioactive material
- Discovered radium and polonium
- Unaware of the danger of exposure to radiation
- Won 2 Nobel prizes, physics and chemistry
- Later died of the effects of radiation
Examples of Radioactive elements
- Uranium
- Plutonium
- Radium
- Polonium
- Thorium
•Radiation hazards in the workplace fall into one of two categories:
- ionizing or
- nonionizing.
types of ionizing radiation
Radiation
- Combination of energetic nuclear particles and includes alpha rays, beta rays, gamma rays, X-rays, neutrons, high speed electrons, and high speed protons.
- The emission (انبعاث ) (sending out) of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization.
- Radiation is energy travelling through space. Sunshine is one of the most familiar forms of radiation.
Restricted area:
Any area to which access(entry)is restricted (limited)in an attempt to protect employees from exposure to radiation or radioactive materials
Dose
The amount of ionizing radiation absorbed (يمتص)(take in, sucked in) per unit of mass by part of the body or the whole body
Rem
•A measure of the dose of ionizing radiation to body tissue stated in terms of its estimated biological effect relative to a dose of one roentgen, ® of X-rays.
Radiation area:
•Any accessible area in which radiation hazard exists that could deliver doses as follows:
- •within one hour a major portion of the body could receive more than 5 millirems, or within 5 consecutive days a major portion of the body could receive more than 100 millirems.
Personal monitoring (watching) devices
- Employers must conduct comprehensive (full, overall) surveys to identify and evaluate radiation hazards present in the workplace from any and all sources.
- Employers must require the use of appropriate personnel monitoring devices (instrument, tool) by any employee who enters a high radiation area.
Caution signs
•The universal color scheme for caution signs and label warning of radiation hazards is purpleor magenta ( reddish-purple) superimposed on a yellow background.
•Both Occupational Safety and Health Administration (OSHA) and ………………….. (NRC) require caution signs in:
Nuclear Regulatory Commission
- radiation areas,
- high radiation areas,
- Airborne(in air) radiation areas,
- areas containing radioactive materials, and
- containers in which radioactive materials are stored or transported
the caution sign figure shows:
- •The universal symbol for radiation, along with the appropriate warning words, this symbol should be used on signs and labels.
- A warning sign and label that may be used in various radioactive settings
•On containers, labels should also include the following information:
- quantity of radioactive material,
- kinds of radioactive material, and
- date on which the contents were measured.
Evacuation (move out) soundwarning signal
- Companies that produce, use, store, or transport radioactive materials are required to have a signal generating system that can warn their employees whenever the need arises for an urgent (serious, very important)evacuation.
- A sufficient number of signal generators must be installed to cover all personnel who may need to be evacuated.
- The signal shall be unique, unduplicated, (very special) and instantly recognizable in the plant where it is located.
- The signal must be long enough in duration to ensure that all potentially (possible, likely) affected employees are able to hear it.
- The signal generator must respond automatically without the need for human activation, and it must be fitted with backup power.
Radioactive material & non-restricted area
- Radioactive material stored in unrestricted areas “shall be secured against unauthorized (unapproved)removal from the place of storage.”
- The radioactive materials should not be handled and transported, intentional or inadvertent (unintentional)by persons who are not qualified to move them safely.
Radioactive material disposal
- transfer to an authorized (official, legal) recipient(the one who receive).
- transfer in a method approved by the Atomic Energy Commission (AEC)
- or transfer in a manner approved by any state that has an agreement with the AEC.
•Immediate reporting is required for the following incidents:
- Exposure of the whole body of any individual to 25 remsor more of radiation.
- Exposure of the skin of the whole body of any individual to 150 remsor more of radiation.
- Exposure of the feet, ankles, hands, or forearms of any individual to 375 remsor more of radiation.
- If an incident meeting one of these criteria occurs, the employer must notify the proper authorities immediately
Radiation overexposure written report
- In addition to the immediate and 24 hour notification requirements, employers are required to follow up with a written report within 30 days.
- Written reports are required when an employee is exposed to radiation or when radioactive materials are on hand in concentrations greater than the specified limits.
Non ionizing radiation
- Non ionizing radiation encompasses (includes)visible, ultraviolet, infrared, microwave, radio and alternating current (AC) power frequencies (1015Hz or less).
- Radiation at these frequencies can cause blisters (burns, hurt) and blindness.
- There is strong evidence (proof, confirmation) of a link between non ionizing radiation and cancer.
warning symbol for radio frequency
Non ionizing radiation concerns
- Visible radiation: This can be a hazard to employees whose job requires color perception (understanding).
- Ultraviolet radiation:most common source is the sun – can cause sunburn, skin cancer, and cataracts.
- Infrared radiation: Creates heat. Heat stress, dry skin and eyes.
- Primary sources are high temperature processes such as production of glass and steel.
- Radio frequency (RF) and microwave (MW) radiation: Microwave frequencies makes your skin feel warm. RF radiation may penetrate the body.
- Laser: Hazards include thermal threat to the eyes and the threat from electrocution of the power source.
- Smoke created by lasers in some processes can be toxic.
Non ionizing radiation concerns
Precautionary measures include: (ultraviolet radiation)
- sunglasses that block out ultraviolet rays and protective clothing.
- Other sources include lasers, welding arcs, and ultraviolet lamps.
Use of RF and MW radiation includes:
- cellular phones,
- high frequency welders,
- communication transmitters,
- radar transmitters, and
- microwave drying equipment
