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What is radioactivity?

Atoms with unstable nuclei are constantly changing as a result of the imbalance of energy within the nucleus. When the nucleus loses a neutron, it gives off energy and is said to be radioactive. Radioactivity is the release of energy and matter that results from changes in the nucleus of an atom.

What is a radioisotope?
isotopes are atoms of the same element that have a different number of neutrons. In other words, the atoms have the same number of protons but a different number of neutrons in the nucleus. Because the like charges of the protons repel each other,there are always forces trying to push the atom nucleus apart. The nucleus is held together by something called the binding energy.

What is secondary containment?

A safeguarding method used to prevent unplanned releases of toxic or hazardous compounds into uncontrolled work areas. It’s a level of containment that is external to and separate from primary containment. Secondary containment is a method of safeguarding used to prevent unauthorized releases of toxic or hazardous gases into uncontrolled work areas. Secondary containment means those methods or facilities in addition to the primary containment system.

General Guidelines for Secondary Containment of Radioactive Isotopes in Laboratories

Radioactive isotopes should be stored in secondary containers to prevent or minimize the possibility of accidental release as well as to ensure compliance with certain local and state regulations dealing with chemical storage. Requirements for secondary containment are based on container size, not the volume of liquid inside the container. Regardless of quantity, all storage of hazardous liquid chemicals in close proximity to floor drains, hood cup sinks, or storm drains must be in secondary containers.

• H-3 (tritium)

• C-14

• S-35

• P-32

• I-125

• P-33

PPE is used to prevent contamination of skin or clothing. PPE is required if there is a possibility of contamination. PPE includes:

• Labcoat with sleeves long enough to cover the arms to the wrists, and long enough to cover the torso to the thighs. Wear with the closures fastened.
• Eye protection ‚ required for all lab work.
• Closedtoe shoes worn to protect the feet from splashes.
• leg covering worn to protect the legs from splashes.

Disposable gloves worn to protect the skin of the hands and wrists from contamination. Gloves are most effective if two pairs are worn at a time, with the outer pair changed frequently.

Equipment

· Review the procedure ahead, preparing a list of all materials that might possibly be required.

· Assemble all items needed. If you have everything you will not need to leave the process unattended while you get additional equipment.

· A dry run (no radioactive materials) using the equipment is usually a good idea.

Emergency Supplies

· Try and foresee what problems might occur, including spills.

· Store the appropriate materials that may be needed close to the work area. Some examples would be extra gloves and absorbent covering, wipes, paper towels, plastic bags, forceps, and decontamination solution.

· If a spill can be contained immediately, contamination spread and personnel contamination can be avoided or minimized.

Protective Clothing

· Lab coats, gloves, closedtoe shoes, coverings for the legs, and safety glasses are required when you are handling unsealed radioisotopes.

· Have enough gloves for frequent changes.

· Information on more specialized protective equipment is available from Radiation Safety

External Dosimetry

· When gamma or higherenergy beta emitters are used, radiation dosimetry may be required.

· Depending on the isotope and amounts to be handled, TLD finger dosimeters and/or whole body badges will be assigned.

· The RUA will indicate what, if any, dosimetry is required.

· Dosimeters must be worn whenever handling the material for which they are assigned.

· Store dosimeters away from radioactive materials and heat.

Instrumentation

· Use of radioisotopes other than H3 may require an appropriate radiation survey meter.

· Minimum survey meter requirements are indicated on your RUA.

Radioactive Waste

· Place adequate waste receptacles (appropriately labeled) on the work surfaces so waste may be contained immediately after it is produced.

· For dry waste, a plastic bag in a can or Plexiglas box on the work bench may be used. This avoids transfers of contaminated items to the waste area during the procedure.

· Liquid waste containers may also be kept on the bench in secondary containers (such as a 1 gallon bottle in a plastic bag inside a paint can) lined with plastic bags.

· As appropriate, shield the waste receptacles for all isotopes except tritium.

· Do not allow wastes to accumulate in the work area.

Dry runs

· Before performing a new procedure with radioisotopes, it is sometimes helpful to make a dry run without radioactivity, or at reduced levels.

· In some cases colored water may be added to simulate the radioisotope. This will identify exactly which materials and methods are needed, and space and time requirements.

· Dry runs may give you an indication of the most likely routes of exposure or contamination and adjustments made to reduce the hazard.

Equipment

· Review the procedure ahead, preparing a list of all materials that might possibly be required.

· Assemble all items needed. If you have everything you will not need to leave the process unattended while you get additional equipment.

· A dry run (no radioactive materials) using the equipment is usually a good idea.

Emergency Supplies

· Try and foresee what problems might occur, including spills.

· Store the appropriate materials that may be needed close to the work area. Some examples would be extra gloves and absorbent covering, wipes, paper towels, plastic bags, forceps, and decontamination solution.

· If a spill can be contained immediately, contamination spread and personnel contamination can be avoided or minimized.

Protective Clothing

· Lab coats, gloves, closedtoe shoes, coverings for the legs, and safety glasses are required when you are handling unsealed radioisotopes.

· Have enough gloves for frequent changes.

· Information on more specialized protective equipment is available from Radiation Safety

External Dosimetry

· When gamma or higherenergy beta emitters are used, radiation dosimetry may be required.

· Depending on the isotope and amounts to be handled, TLD finger dosimeters and/or whole body badges will be assigned.

· The RUA will indicate what, if any, dosimetry is required.

· Dosimeters must be worn whenever handling the material for which they are assigned.

· Store dosimeters away from radioactive materials and heat.

Instrumentation

· Use of radioisotopes other than H3 may require an appropriate radiation survey meter.

· Minimum survey meter requirements are indicated on your RUA.

Radioactive Waste

· Place adequate waste receptacles (appropriately labeled) on the work surfaces so waste may be contained immediately after it is produced.

· For dry waste, a plastic bag in a can or Plexiglas box on the work bench may be used. This avoids transfers of contaminated items to the waste area during the procedure.

· Liquid waste containers may also be kept on the bench in secondary containers (such as a 1 gallon bottle in a plastic bag inside a paint can) lined with plastic bags.

· As appropriate, shield the waste receptacles for all isotopes except tritium.

· Do not allow wastes to accumulate in the work area.

Dry runs

· Before performing a new procedure with radioisotopes, it is sometimes helpful to make a dry run without radioactivity, or at reduced levels.

· In some cases colored water may be added to simulate the radioisotope. This will identify exactly which materials and methods are needed, and space and time requirements.

· Dry runs may give you an indication of the most likely routes of exposure or contamination and adjustments made to reduce the hazard.

Opening shipments

· Usually, the greatest amount of radioactive material is handled when the isotope stock bottle is opened. If the material is such that there is a possible pressure buildup during shipment or storage, the container should be opened in an appropriate containment.

· A fume hood is a good place to open packages.

· Always assume the outside of the primary container (the vial) is contaminated and handle with gloves.

Direct handling of radioactive materials

· The greatest source of inadvertent contamination is caused by contact with contaminated work gloves. Nearly all isotope work will involve some direct handling of open isotope containers. Whenever this occurs, assume your gloves are contaminated.

· Change gloves if a”clean” item is to be handled. Check your gloves/lab coat often (with a survey meter, except for H3).

· If you need to wear the gloves away from the work area be aware of the potential for contamination.

· A dry run may show when gloves should be changed.

· Cap solutions that are not to be used immediately.

· Do not pipette radioactive material by any mouth procedure.

Remote handling of radioactive materials

· Some isotopes may present an external exposure hazard.

· Some remote manipulation may be necessary.

· Use of tongs, forceps, pliers, etc., may lower radiation dose.

· Metal implements should be rubbertipped for a more secure grip.

· If you use an unfamiliar technique, it should first be practiced with lowhazard materials or a dry run.

· Handling tools are likely to become contaminated and should be checked and cleaned as needed.

· These tools need to be properly labeled.

Transferring radioactive materials off campus

Contact Radiation Safety at least 48 hours prior to shipment. Radiation

Safety will:

a) help you package the materials.

b) verify that the shipment is allowed (to new location).

c) take care of the paperwork.

d) help ship and track the shipment.

e) help resolve shipping problems (especially if the materials are being shipped out of the United States.

Transferring radioactive materials on campus

· Contact Radiation Safety before transferring radioactive materials between RUAs.

· When making liquid transfers, use double containment to prevent spills.

· For large volumes of radioactive solution or waste, a tray or tub should be used so all the liquid can be contained in case of a spill.

· When moving an isotope solution away from the bench, secondary containment is almost always needed.

· Use rigid, covered unbreakable carriers, if isotopes are to be transferred through public use areas (such as hallways).

(1) from nature, such as radon in the air or radium in the soil;

(2) from machine-produced nuclear interactions in devices, such as linear accelerators and cyclotrons;

(3) from nuclear reactors.

A linear accelerator is a long, straight tube in which charged particles gain energy through oscillating electromagnetic fields. A cyclotron is an accelerator in which charged particles travel in an almost circular path, rather than in astraight path as in a linear accelerator. Radioisotopes produced in linear accelerators are used in some modern nuclear medicine procedures.

The nuclear reactors that produce radioisotopes bombard atoms with high-energy neutrons. The research reactors used for this purpose do not produce electricity and are much smallerin size and power than large power reactors. Reasearch reactors are mostlyused for training and for identifying the composition of certain elements.

Forty-seven research reactors are licensed by the NRC to operate in the United States. They are located mostly at large universities.

Because of the potentially hazardous properties of radioisotopes, their use must be closely regulated to ensure that public health and safety are protected.

The licensing and regulation of radioisotopesin the United States are shared by the NRC, the U.S. Environmental Protection Agency (EPA), and many State governments. The EPA is alsoresponsible for, among other things, setting air emission and drinking water standards for radionuclides. The States regulate radioactive substances that occur naturally or are produced by machines, such as linear accelerators or cyclotrons. The Food and Drug Administration (FDA) regulates the manufacture and use of linear accelerators; the States regulate their operation.

What Is the Role of the Nuclear Regulatory Commission?

The NRC is the Federal agency given the task of protecting public health and safety and the environment with regard to the safe use of nuclear materials. Among its many responsibilities, the NRC regulates medical, academic, and industrial uses of nuclear materials generatedby or from a nuclear reactor. Through a comprehensive inspection and enforcement program, theNRC ensures that these facilities operate in compliance with strict safety standards.

The NRC has relinquished its authority to regulate certain radioactive materials, including some radioisotopes, to most of the States. These States, which have entered into an agreement assuming this regulatory authority from the NRC, are called Agreement States and are shown on the map below. Agreement States like the NRC, regulate reactor-produced radioisotopes within their borders and must provide at least as much health and safety protection as the NRC.

List of current regulations and supporting documents in Malaysia

• Atomic Energy Licensing Act 1984

• Radiation Protection (Licensing) Regulations 1986

• Radiation Protection (Basic Safety Standard) Regulations 1988

• Radiation Protection (Transport) Regulations 1989.

• Code of Practice for Radiation Protection (Medical X ray Diagnosis) MS838:1985

• Code of Practice on Radiation Protection in Industrial Radiography (LEM/TEK/33:1995)

• Guide for Safe Transportation of Radioactive Minerals in the Amang Upgrading Industry (LEM/TEK/32:1994)

• Statistics on facilities, inspections, number of radiation workers, etc

• Inspection Procedures

• Inspection checklists

• Enforcement procedures

• Prosecution procedures

• Licence application forms

• Atomic Energy Licensing (Exemption Order) 2001 – Scanning Electron Microscope

• Atomic Energy Licensing (Exemption Order) 2001 – Zirconium Silicate

• Atomic Energy Licensing (Exemption Order) May 2002 – Low Level Radioactive Sources

• Atomic Energy Licensing (Exemption Order) May 2002 – Irradiating Apparatus With Energy Below 5 keV

Source: Country Report on Status of Radiation Protection in Malaysia by Mohf Yusof Mohd Ali

The basic precautions are used in order to reduce contamination and personnel exposure. The basic precautions can be divided into laboratory design and equipment, and auxiliary equipment and services.

Laboratory Design and Equipment

• General Working Conditions

Laboratories and equipment specially designed for the purpose of radioactive isotopes are used. No work should be undertaken in these rooms other than that concerned with the application of radioactive isotopes.

• Size of Radioactive Laboratory

The size of a radioactive laboratory is important and suitable provision for adequate floor space should be made. A laboratory designed for one scientist working alone should have a total floor area of 200 sq.ft.

• Floors

The floors should have a smooth, continuous surface, as far as possible, such as stainless steel, painted concrete, or linoleum. Absorbent floors, such as those made of wood, should be avoided. Asphalt tile and similar materials can also be used. The ease of replacement of sections of tile floor compensates for the hazard of crack contamination. Floors should be cleaned daily by wet mopping, or by the use of moist compound. Dry sweeping should be avoided as it may lead to an active dust hazard.

• Walls, Ceiling and Woodwork

Walls, ceiling and woodwork should be finished with a non-porous washable surface, which may be cleaned to remove accumulation of radioactivity. A plastic paint, such as Tygon, is particularly useful as it may be easily removed with acetone if necessary.

• Ventilation

All laboratory operations should be conducted in hoods which will be provided with forced ventilation sufficient to keep the beta active content of the room air below 10-_ curies per cu. m. or 3,700 disintegrations per sec. per cu. m. Experience has shown that the minimum air flow which is sufficient for an efficient cabinet is 150 linear ft. per min., with the cabinet front open 1 ft. Specially hazardous operations, such as handling long-lived bone-seeking isotopes in injection or inhalation studies on animals, should be conducted by personnel wearing suitable respirators or supplied-air masks. Hoods with individual filter systems for the exhaust air are highly recommended. Multiple hood systems are dangerous because reverse air currents may occur. Personnel outside the laboratory must be protected from the radioactive material forced out of the vent from the hoods and careful consideration should be given to this when designing a radioactive laboratory.

• Equipment

Special equipment suitable for the type and level of activity being used should be provided for each type of operation. This should include handling tools such as tongs, forceps: trays and mechanical holders. Long handled tools may provide adequate protection by distance where millicurie amounts of beta or gamma activity are encountered. When the isotopes concerned are chiefly beta emitters, efficient use can be made of transparent plastic shields fitting closely around the equipment to a low close handling with good visibility. Containers for the active material should incorporate the necessary shielding as close to the source as possible. Containers for liquid samples should always be reinforced by an outer, unbreakable container.

• Hoods and Benches

Laboratory furniture should be portable and should not have drawer or cupboards which tend to collect dust and unnecessary apparatus. Portable tables and cabinets are adequate for radioactive laboratories. All work with radioactive material should be done in fume cabinets and experience has shown that the sloping front design is more convenient for continuous work than a straight front. Portable laboratory tables should be painted with Tygon or some other plastic covering. The table tops should be covered with linoleum or glass. The most practical method for covering benches is by means of sheet lead. Services and controls should be outside the cabinet on the bench. This procedure enables one to make complete and thorough clean-ups with a minimum of waste and expense. The purpose of the absorbent paper is to catch minor spills, and it is advisable to change this paper after each laboratory experiment. The work bench should be equipped with papers for the prompt removal of spills. Drawers in work benches should be washable and have removable liners.

• Storage Facilities

Radioactive materials should be stored at a safe distance from all personnel in the building, if possible. If storage at a safe distance cannot be arranged, a small "castle" built of lead bricks should be placed under the storage bin, as well as around it. A heavy lead cover should be secured for the bin.

• Counting room

Counting equipment and other radiometric apparatus should be set up in a nearby room. It is as a rule, not desirable to have counting units in the radioactive laboratory because of the possibility of contamination. The walls of the counting room should furnish shielding against radiation from sources in nearby laboratories. Much care is needed to make sure that the counting room does not become contaminated by very small amounts of radioactive material which do not constitute a health hazard but will hinder a precise measurement.

• Auxiliary Equipment and Services

The chief auxiliary equipment and services required in the operation of a radioactive laboratory, handling quantities of material from one to 100 mc are as follows:

1. Health instruments.

2. Film monitoring.

3. Special laboratory clothing.

4. Special cleaning services.

5. Disposal of radioactive waste materials.

· Health Instruments

For all work with millicurie amounts or greater, the laboratory should have an electroscope or portable ionization chamber with direct current amplifier reading directly in dosage rate (mr. per hr.). This instrument should be capable of measuring dosage rates at least from 6 mr. per hr. to 100 mr. per hr. A removable cover on the ion chamber making it sensitive to beta particles is useful. Portable Geiger counter probe monitors are indispensable for locating and checking sources and monitoring the cleaning up of spills. This instrument is useful in checking shoes, clothing and hands for contamination and it may be used to make measurements in certain experiments.

Film Monitoring

Monitoring films should be worn by all laboratory personnel. Films should be developed and read every week and all over-exposures reported immediately to the director of the laboratory. The use of films makes certain that personnel are not receiving an unreasonable amount of gamma radiation. Pencil chambers and special films worn on the fingers or wrist should be used by personnel when working in comparatively high radiation fields. Special Laboratory Clothing the degree of protection required is a function of the activity used. Even tracer amounts should be handled with laboratory coats protecting normal attire. In a biological laboratory where routine work is done with radioactive materials, it is good practice to have special laboratory coats or coveralls, rubbers or special shoes, and even special trousers and shirts, which are kept for use in the laboratories only. Rubber gloves should be worn while handling active materials which may give rise to contamination of the hands.

Special Cleaning Services

The laboratories should be kept very clean at all times and the equipment used by the janitor. Mops and pails should be used for the active laboratory only and not for other parts of the building. Spills of solution containing radioactive materials should be cleaned up at once by the scientist who was responsible for the accident. He should wear rubber gloves and take proper precautions. When he considers the area to be clean, it should be carefully monitored with a sensitive detector. Careful cleaning up of all spills will help to keep the laboratory free from contamination.

Disposal of Radioactive Waste Materials

Solid Active Materials: The laboratory should have a closed and clearly labeled garbage can, with a moisture proof disposable liner, to hold the discarded absorbent bench paper, wiping papers and other solid active materials. Regular collections of this active waste material should be made. The eventual disposal of such items depends upon the half-life and toxicity of the isotopes used. In the case of isotopes with short half-lives, holding the materials in a controlled place until their residual activity is very small, is a good method. With a long-lived isotope, the best method is burying in a special disposal area. Special care should be given to dry waste which might dust.

Active Solutions: Radioactive waste solutions should only go into ordinary sewers if the amounts of radioactive material are low enough to constitute no possible hazard. Whenever possible, the principal activity in the waste solution should be precipitated, and disposed of as active solid material. Urine from isotope-injected animals or patients, and liquors from

equipment or clothing decontamination, may require attention as radioactive solutions.

The following precautions apply to "safe" amounts as well as to larger quantities of radioactive isotopes.

Protection of Hands

Every precaution should be taken to avoid getting radioactive isotopes on the hands. The hands should be kept at a safe distance from sources as even small sources will cause burns if close to the skin. The hands should be protected by rubber gloves or paper when handling radioactive materials. After working with radioactive materials, the hands should be thoroughly washed for two or three minutes using plenty of soap. A check of the hands should be made with a monitoring instrument after washing and the hands should be washed again if necessary.

Cleaning of Glassware

Scrupulous care in the cleaning of glassware is necessary. All vessels should be marked after use and placed apart from other equipment so that it can be given special attention in cleaning. Even after cleaning, glassware should be kept separate from other equipment. Adsorption of active materials on glassware is a very common phenomenon.

Handling Solutions

Isotopes should be used in solution of possible. Of course, all spills of radioactive material must be cleaned up immediately and thoroughly and the area should then be checked with a monitoring instrument to ensure that no significant activity remains. Radioactive solutions should never be pipette by mouth, some other device should be used. All operations should be done over surfaces covered with paper. If possible, stainless steel trays lined with blotting paper should be used. Experience has shown that a glass container should never be trusted and a secondary container, preferably stainless steel, should always be used. Pipettes, stirring rods, capillary tubes and similar equipment should never be placed on the bench after use but should always be put in small trays lined with blotting paper. Hot plates should be protected with asbestos paper in case a solution boils over.