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Radiation Safety Guide


 

Radiation Safety Guide

SECTION 10: Laboratory Procedures for Radioisotopes


Radioisotope Inventory (top)

In each laboratory a Radioisotope Inventory Log shall be maintained, containing an inventory of radioisotopes, noting the element, its mass number, date received, amount received, dates of withdrawal for use and amount withdrawn, date of disposal of waste, manner of disposal, and estimated amount of waste. In short, a continual record must be maintained from receipt to disposal or decay.

The maintenance of an inventory of target activity levels for the targets which are routinely activated and investigated at the Jadwin Cyclotron is difficult because of the broad spectrum of activities and activity levels met in these targets. However, it is possible to estimate activity levels or to express the data in mr/hour at some specified distance. It is necessary that a record be kept indicating the disposition of these materials.

Reports (top)

Two monthly reports must be filed by the "Authorized User" with the Office of Environmental Health and Safety: an inventory of radioisotopes on hand (including all wastes not yet removed from the University) and a summary of radioisotope disposals. The Office of Environmental Health and Safety collects and collates the inventory data from all "Authorized Users." The "Authorized User's" inventory report (using EHS-HP Form #201) is filed with the Office of Environmental Health and Safety each month and identifies all radioactive material on hand, including wastes. The forms for these reports are available from the Office of Environmental Health and Safety.

Survey Equipment (top)

1. A person using open or "Sealed Sources," opening packages containing radioisotopes, or performing physical or chemical manipulation of radioisotopes must have immediately available a suitable, operative radiation detector. This detector must be able to indicate either dose rate or activity as may be proper considering the nature and activity of the source.


2. All portable radiation survey meters must be registered with the Office of Environmental Health and Safety in order for calibration services to be provided and calibration and repair records to be maintained. Any "Authorized User" who purchases a new survey meter or otherwise obtains a survey meter not previously registered must promptly notify the Office of Environmental Health and Safety.


3. Each portable radiation survey meter must have a radioactive check source affixed to it or otherwise provided with it. Check sources are available from the Office of Environmental Health and Safety. The check source is provided to enable the "User" to determine whether a survey meter is operating properly. Each "User" must performance test a survey meter before first using it on a given day and should test it as often as necessary thereafter to be assured that the meter is functioning satisfactorily.

4. When a meter is performance tested, the meter reading must fall within ±10% of the check source reading indicated on the label affixed to the meter. Any meter whose response does not fall within this range is considered nonfunctional and should be taken out of service.


When a survey meter is not functioning properly or needs to be repaired for any reason, the Office of Environmental Health and Safety should be notified since the Office of Environmental Health and Safety maintains repair and calibration records for each survey instrument and can offer limited diagnostic and repair services.


5. All portable radiation survey instruments must be periodically calibrated using the calibration service provided by the Office of Environmental Health and Safety and must be calibrated following servicing or repair. Routine calibrations are scheduled by the Office of Environmental Health and Safety; the "Authorized User" is notified concerning the calibration details. When a meter has been sent out for repair and has been returned, the "Authorized User" must notify the Office of Environmental Health and Safety to arrange for the meter's calibration.

Operational Work Area Surveys (top)

Survey Requirements


In addition to the routine surveys made by the Health Physics staff, laboratory personnel manipulating open sources of radioactive materials shall conduct operational work area surveys. These surveys shall be performed using portable survey meters and/or wipe testing, as appropriate. Surveys must be performed:

  • At the end of an experimental procedure and at the end of each day for multi-day procedures;
  • During the manipulation of millicurie quantities of open sources (the frequency and exact timing of this type of survey is left to the judgment of the individual performing the experiment);
  • Following withdrawals from stock sources containing millicurie quantities.


Records of such surveys must be kept. The records should include the name of the surveyor, the date, the survey results, whether positive or negative, and follow-up actions taken if contamination is found.


Action Levels

Paragraph 10.D.3 provides limits for permissible levels of removable contamination on surfaces in restricted areas. When the operational work area survey indicates the presence of contamination on surfaces, e.g., floors, walls, bench tops, etc., in excess of the limits specified in Paragraph 10.D.3, prompt decontamination is required. However, prompt decontamination is encouraged when contamination levels exceed 100 dpm/100 cm2 for all beta, gamma or X-ray emitters and at 10 dpm/100 cm2 for alpha emitters.


In the event substantial contamination is found, e.g., in an amount exceeding the quantity specified in Appendix C or if contamination is widespread, the "Health Physicist" must be notified immediately.


Removable Contamination Limits

The limits for removable contamination on surfaces, e.g., work surfaces, floors, walls, etc., in restricted areas are:

  Alpha Emitters Beta, Gamma, or X-Ray Emitters Low Risk Beta, Gamma, or X-Ray Emitters*
Surfaces in the Restricted Area 220 dpm per 100 cm2 2200 dpm per 100 cm2 22,000 dpm per 100 cm2

*Low risk beta, gamma, or X-ray emitters are those isotopes with beta energies less than 0.2 MeV, and/or gamma or X-ray emissions less than 0.1 R/hr at 1 meter per curie and with permissible air concentrations greater than 10-6 microcuries per milliliter.

Personal Surveys (top)

Survey Requirements

When manipulating open sources of radioactive material, thorough surveys of one's person and clothing must be performed, using portable survey meters and/or wipe testing, as appropriate. Surveys must be performed:

  • At the end of an experiment and at the end of each day for multi-day procedures
  • During manipulation of millicurie quantities of open sources (the frequency and exact timing of this type of survey is left to the judgment of the individual performing the experiment)
  • During and following the opening of radioactive material packages
  • Following withdrawals from stock sources containing millicurie quantities;
  • Prior to exiting the restricted area.

Records of such surveys must be kept. The records should include the name of the surveyor, the date, the survey results, whether positive or negative, and the follow-up actions taken if contamination is found.

Action Levels

Paragraph 10.E.3 provides limits for permissible levels of contamination on personal protective clothing and the skin. When a survey indicates skin contamination in excess of these limits, immediate efforts to decontaminate the skin are required. However, decontamination of the skin is encouraged at any level of contamination. Cases involving contamination of the skin, regardless of the quantity, must be reported to the "Health Physicist."

Contamination on clothing in excess of the limits specified in paragraph 10.E.3 requires that the contaminated clothing be removed promptly. Prompt decontamination of clothing is encouraged at 100 dpm/100 cm2 for all beta, gamma or X-ray emitters and at 10 dpm/100 cm2 for alpha emitters.

Contamination Limits

The limits for contamination on personal protective clothing and the skin are:

  Alpha Emitters Beta, Gamma, or X-Ray Emitters Low Risk Beta, Gamma, or X-Ray Emitters*
Personal Protective Clothing 220 dpm per 100 cm2 2,200 dpm per 100 cm2 22,000 dpm per 100 cm2
Skin 220 dpm per 100 cm2 220 dpm per 100 cm2 2,200 dpm per 100 cm2

*Low risk beta, gamma, or X-ray emitters are those isotopes with beta energies less than 0.2 MeV, and/or X-ray emissions less than 0.1 R/hr at 1 meter per curie and with permissible air concentrations greater than 10-6 micro-curies per milliliter.

Smoking and Eating Restrictions (top)

    1. Eating, drinking, and smoking is prohibited in laboratories where open sources of radioactive materials are used. Food for human consumption shall not be placed or stored in any equipment such as refrigerators, freezers or ovens in which radioisotopes are stored or used.
    2. For state-licensed radioactive materials (naturally-occurring or accelerator produced radioactive materials which may include such isotopes as H-3, Be-7, Na-22, Cr-51, Mn-54, Fe-55, Co-57, Zn-65, Cd-109, In-111, Bi-210, Ra-226 and its progeny, and natural uranium and thorium), additional restrictions apply. Eating, drinking, smoking and the application of cosmetics is prohibited in any laboratory in which state-licensed radioisotopes in sealed or open form are stored or used.

Protective Clothing (top)

Appropriate protective clothing, including gloves, a full-length laboratory coat, shoes and socks, should be worn at all times for work with any open radioactive source. Gloves, a full-length laboratory coat, shoes, and socks are required to be worn by any person working with an open radioactive source in an amount equal to or exceeding 0.01 times the quantity given in Appendix C for any radioisotope, if such work creates a reasonable potential for contamination. For the most commonly used isotopes, these quantities are 1 mCi for C-14, 10 mCi for H-3, 0.01 mCi for I-125, 0.1 mCi for P-32, and 1 mCi for S-35.

Wearing sandals or open-toed shoes, when handling the quantities specified above, is prohibited.

In-house Movement of Radioisotopes (top)

Radioisotopes moved within a building should be moved in such a way that no radioactive material can be readily released from its container under normal conditions and with sufficient forethought to minimize the spillage of radioactive material. The inner container must be marked "RADIOACTIVE" during transport and shielding must be provided as needed. Radioactive material may not be left unattended during transit. These precautions become especially important when radioactive material is moved through unrestricted areas.

NOTE: Section 14 describes requirements for the intra-campus and off campus transportation and shipment of radioactive materials.

Fume Hoods and Glove Boxes (top)

Experiments involving the use of open radioactive sources which could result in airborne radioactivity should be carried out in fume hoods or glove boxes. Because even ordinary laboratory manipulations can result in the release of airborne radioactivity, all "Users" are strongly urged to use a chemical fume hood for any physical or chemical manipulation of radioisotopes. The "Health Physicist," during review of an application for authorization, will determine whether use of a fume hood or glove box is required and, if so, will make it a condition of approval for the application.

Any use of a biological safety cabinet for radioactive materials should be discussed beforehand with the "Health Physicist." Under certain circumstances, biological safety cabinets are not suitable, for instance, for volatile substances such as radioiodine, since in many cases some air from the cabinet is exhausted to the room.

Except as noted below, hoods for radioisotope work must have an average face velocity of at least 50 linear feet per minute. Experiments involving alpha-emitting radioisotopes and radioiodines must be performed in hoods with an average face velocity of at least 95 linear feet per minute. Hood and glove box surfaces should be protected to prevent contamination of fixed surfaces that may be difficult to decontaminate.

In consideration of University maintenance personnel who may be called to repair possibly contaminated hoods, all hoods which have been used for radioisotope work are labeled by the Office of Environmental Health and Safety, "This Hood used for Radioactive Material." Any "User" who wishes to use an unlabelled hood for radioisotope work should obtain the proper label from the Office of Environmental Health and Safety.

Airborne Radioactivity (top)

For experiments that may result in the release of airborne radioactive material, a routine air sampling and bioassay program may be required. No operation may be planned and performed that will knowingly result in the release of airborne radioactivity in excess of regulatory limits.

The "Health Physicist," during review of an application for authorization, will evaluate the proposed procedures for any potential for airborne releases. If the "Health Physicist" determines that significant airborne radioactivity is likely to be generated, air sampling will be made a condition of approval of the application.

Caution: It should be remembered that the use of volatile or powdered radioisotopes may result in significant airborne concentrations of radioactive material.

Pipetting (top)

Mouth pipetting of radioactive material is prohibited.

Trial Runs (top)

Work which requires extensive physical and/or chemical manipulation of radioisotopes should not be performed using radioactive material until the techniques, procedures, and equipment have been tested in a trial run. Under certain circumstances, e.g., when an unusually large quantity of radioactive material, a particularly hazardous form of radioactive material, or a new and untested procedure is proposed to be used, the "Health Physicist" may determine that a trial run must be performed before the procedure is carried out using radioactive materials, or, if the use of radioactive materials in the trial run is unavoidable, may determine that a trial run using smaller amounts of radioactive material must be performed. When appropriate, such a requirement will be made a condition of approval for authorization.

Working Surfaces (top)

All work involving physical or chemical manipulation of open radioactive sources shall be performed directly on work surfaces suitable for containment of contamination and easy decontamination. The lining of work surfaces with plastic backed absorbent paper has been found to reduce the spread of contamination.

Labeling (top)

Although labeling of equipment and containers is required only under certain conditions (see Section 9), it is good practice to label all contaminated objects and work surfaces to indicate the presence of radioactive material. Such labeling reduces confusion and prevents others from unsuspectingly using contaminated equipment.

Opening of Shipments (top)

The opening of shipments of radioisotopes must be done in a properly equipped laboratory and only by the "Authorized User" or by an adequately trained individual designated by the "Authorized User." Additional details are found in Section 8.

Security (top)

Visitors to laboratories using "Sources of Radiation" should be supervised by a member of the laboratory staff who is familiar with the activities of the laboratory. All radioactive stock materials and sealed sources must be stored in a secured container or secured storage area when not in use. Any room in which an unattended sealed source is being used must be secured. Exceptions must be approved in writing by the Office of Environmental Health and Safety (EHS). A stock material is defined to be radioactive material as provided by the vendor and does not include material withdrawn from the original stock by a researcher for experimental use. This policy applies to materials for which EHS approval and authorization is required and does not apply to generally-licensed devices, such as smoke detectors, static eliminators, electron capture detectors, exit signs, etc.

Special Equipment and Requirements (top)

In cases where the use of radioactive material presents unique or unusual hazards, special radiation safety equipment, precautions, and procedures may be required as determined in consultation with the "Health Physicist." These might include specialized shielding and equipment, clothing, monitoring equipment, etc. When appropriate, such requirements will be made conditions of approval for authorization.

Animal Use and Care (top)

The use and care of animals used for in vivo experiments with radioisotopes must be done in compliance with the provisions of the Animal Welfare Act of 1970 and amendments thereto, as determined by the Animal Care Subcommittee of the University Research Board. In addition to those requirements, consideration must be given to the special problems of animal waste collection, the disposal of carcasses, airborne radioactivity resulting from exhaled radioactive materials, and the cleaning and decontamination of cages. Required precautions, as determined by the "Health Physicist," will be made conditions of approval for authorization.


       
       
     

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