Radiation Safety Manual
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9.3 - RULES FOR CONTROL AND MONITORING OF PERSONNEL EXPOSURE AND ENVIRONMENTAL RADIATION
This chapter sets forth rules which are intended to assist Authorized and Individual Users in conducting their work safely, in compliance with applicable regulations, and in a manner which will ensure that exposures to ionizing radiation are maintained as low as is reasonably achievable (ALARA). These rules are an implied part of each User's Authorization granted by the RSC.
- Access Control
Access control serves two important purposes, the first is to protect the public by ensuring that the total effective dose equivalent to individual members of the public from licensed operations does not exceed 100 mrem (1 mSv) in a year. The second purpose of access control is to provide for the physical security of licensed radioactive materials. Definitions for the access control terms that follow: unrestricted area, controlled area, and restricted area are quoted from Federal regulations (10 CFR Part 20, Standards for Protection Against Radiation).
- Unrestricted Area
Unrestricted area means an area, access to which is neither limited nor controlled by the licensee.
- No member of the public shall receive a dose exceeding 2 mrem (20 µSv in any one hour, nor shall radioactive material be used or stored in an unrestricted area in quantities that (per isotope) exceed those specified in Appendix C of 10 CFR Part 20 (attached as Appendix E to this Manual). Licensed materials stored in an unrestricted area shall be secured from unauthorized removal or access. Constant surveillance shall be maintained over any licensed material in use (i.e., not in storage) in an unrestricted area.
- Controlled Area
Controlled area means an area, outside of a restricted area but inside the site boundary, access to which can be limited by the licensee for any reason.
If an area contains radioactive material exceeding the quantity specified per isotope in Appendix C of 10 CFR Part 20, it shall be designated a "controlled area" and shall be posted in accordance with Section 9.3.2 of this manual. Access shall be controlled by the responsible Authorized User to ensure that:
- the total effective dose equivalent to an individual member of the public from licensed operations does not exceed 100 mrem (1 mSv) in a year;
- occupational exposures are maintained as low as is reasonably achievable (ALARA);
- licensed materials are secure from unauthorized removal or access; and
- constant surveillance is maintained of licensed materials not in storage.
- Restricted Area
Restricted area means an area, access to which is limited by the licensee for the purpose of protecting individuals against undue risks from exposure to ionizing radiation or radioactive materials. Restricted area does not include areas used as residential quarters, but separate rooms in a residential building may be set apart as a restricted area.
NOTE: It is CUA policy that radioactive materials will not be used or stored in residential buildings.
When an area contains radiation exposure levels >2 mrem/hr (>20 µSv/hr) or contains radioactive material exceeding 10 times the quantity specified per isotope in Appendix C of 10 CFR Part 20 it shall be designated a "restricted area"; it shall be posted in accordance with Section 9.3.2, and access shall be controlled by the responsible Authorized User to ensure that:
- access is limited to authorized personnel equipped with appropriate personal dosimetry;
- visitors are escorted by an authorized individual, are equipped with personal dosimetry; and
- the total effective dose equivalent to any visitor from licensed operations does not exceed 100 mrem (1 mSv) in a year.
"RADIATION AREA" means an area, accessible to individuals, in which radiation levels could result in an individual receiving a dose equivalent in excess of 5 mrem (50 µSv) in 1 hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates.
"HIGH RADIATION AREA" means an area, accessible to individuals, in which radiation levels could result in an individual receiving a dose equivalent in excess of 100 mrem (1 mSv) in 1 hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates.
"AIRBORNE RADIOACTIVITY AREA" means a room, enclosure or area in which airborne radioactive materials, composed wholly or partly of licensed material, exists in concentrations:
(1) In excess of the derived air concentrations (DACs) specified in Appendix B to 20 CFR 20.001-20.2401, or
(2) To such a degree that an individual present in the area without respiratory protective equipment could exceed, during the hours an individual is present in a week, an intake of 0.6 percent of the annual limit on intake (ALI) or 12 DAC-hours.No practice or procedure having the potential to create a high radiation area or airborne radioactivity area shall be performed at CUA without the express consent of the RSC.
- Posting Of Controlled and Restricted Areas
The RSO shall furnish, and the responsible Authorized User shall post at each entrance to a controlled or restricted area a sign bearing the radiation caution symbol, the word "CAUTION" and one or more of the following wordings as appropriate, "RADIOACTIVE MATERIAL," "RADIATION AREA," or "HIGH RADIATION AREA."
For a controlled area (i.e., radioactive material present in quantity exceeding that specified in Appendix C of 10 CFR Part 20 the words "RADIOACTIVE MATERIAL" shall be included on the sign(s).
Postings for restricted areas shall at a minimum include the words "RADIOACTIVE MATERIAL" on the sign(s). Restricted areas with radiation exposure levels >5 mrem/hr (>50 µSv/hr) shall additionally include the words "RADIATION AREA" or, if the radiation exposure level is >100 mrem/hr (>1 mSv/hr), the words "HIGH RADIATION AREA."
The name and telephone numbers (office and residence) of the Authorized User responsible for a controlled or restricted area shall also be included on or adjacent to each sign required by this section.
- Occupational Dose Limits
Federal regulations (10 CFR 20, Subpart C, Section 20.120) limit the occupational dose for an adult individual (18 years of age or older) to an annual total effective dose equivalent (TEDE) of 5 rems (50 mSv). This total effective dose equivalent is the sum of both external and internal exposure to the whole body (defined to include the head, trunk, gonads, arms above the elbow, and legs above the knee). The regulations further state that the annual occupational dose limit for a minor is 10% of the adult limit or, 500 mrem (5 mSv). Similarly, 500 mrem (5 mSv) is also the federal dose limit to an embryo/fetus during a declared pregnant woman's entire pregnancy.
Annual limits are also established by the NRC for exposure to the lens of the eye, to the skin, and to the extremities (defined as the hands , elbows, arms below the elbow, feet, knees,and legs below the knee). These limits are: an eye dose equivalent of 15 rems (0.15 Sv), and a shallow-dose equivalent of 50 rems (0.5 Sv) to the skin or any extremity.
To maintain CUA personnel exposures ALARA and ensure compliance with federal limits, the annual CUA occupational dose limit for all individuals (minors, adults and declared pregnant women) shall be 500 mrem (5 mSv) TEDE. Furthermore, the CUA occupational ALARA limit goals for exposure to the lens of the eye, skin, and extremities shall be 10% of the applicable federal limits. Table 9.3.3 presents the federal and CUA occupational exposure limits herein described (expressed in both millirem and milliSieverts).
Occupational dose limits
10 CFR 20
Total Effective Dose Equivalent:
-for an adult individual
-for a minor
-for a declared pregnant woman
Eye dose equivalent: 15,000 (150) 1,500 (15) Shallow dose equivalent to the skin or to any extremity: 50,000 (500) 5,000 (50)
Each individual shall be responsible for ensuring that his/her occupational exposure is maintained ALARA. Each Authorized User shall control operations so that no individual working in a controlled or restricted area receives from sources in the possession of CUA an occupational dose equivalent that exceeds the ALARA goals established herein. Should any CUA employee receive a dose exceeding an ALARA goal, the RSO will perform an investigation and document relevant findings.
NOT WITHSTANDING THE PRESCRIBED LIMITS, OPERATIONS SHALL BE CONDUCTED SO AS TO MAINTAIN RADIATION EXPOSURES AS LOW AS IS REASONABLY ACHIEVABLE (ALARA)
- External Exposure
External exposure means that portion of the dose equivalent received from radiation sources outside the body and is measured by personal dosimetry (i.e., a film badge and/or thermoluminescent dosimeter). Individuals shall maintain their external exposure ALARA through appropriate application of the Time, Distance, and Shielding principles. To wit:
- a reduction in the time spent in the presence of radioactive material will reduce the dose received from that material;
- an increase in distance from a source of radioactivity will reduce the dose rate by the inverse of the square of the distance from that source (i.e., doubling the distance decreases the dose rate by a factor of four, trebling the distance decreases the exposure rate by a factor of nine, etc);
- an increase in the amount of shielding between the individual and the source will reduce the exposure received from the source.
- If an individual receives a monthly external exposure in excess of 125 mrem (1250µ) limit, an investigation shall be conducted by the RSO and responsible Authorized User to determine the cause.
- Internal Exposure
Internal exposure means that portion of the dose equivalent received from radioactive material taken into the body and is measured through bioassay (i.e., in vivo body counting and/or in vitro assay of urine and/or fecal samples). Internal exposure results from injection, ingestion, or inhalation of radioactive material. It shall be controlled by following sound laboratory practices (Section 9.3.17), and by limiting airborne and surface contamination (Sections 184.108.40.206 and 220.127.116.11, respectively).
- Airborne Contamination Limits
Federal regulations have established airborne radioactivity concentration limits to prevent overexposure of any organ in the body as a result of breathing contaminated air. These limits are specified in (10 CFR 20, Appendix B, Table 1). The table lists, by isotope, an annual limit on intake (ALI) and the derived air concentration (DAC - that concentration which, if breathed for 2,000 hours, would result in inhalation of one ALI). If more than one isotope is airborne, the sum of fractions rule applies.
- Surface Contamination Limits
Surface contamination limits for unrestricted, controlled, and restricted areas on the CUA campus are given in Table 18.104.22.168 (from NRC Regulatory Guide 8.23). These limits are subject to the following conditions and interpretations:
a. The tabulated limits are to be used as a guide and, in practice, professional judgment shall be used by the RSO to determine the acceptability of the actual contamination.
b. Although it is believed that the recommended limits would not result in a health hazard, good radiation protection practice dictates that contamination levels should be kept ALARA.
Removable surface contamination limits on the CUA campus
Type of surface
Unrestricted and Controlled areas 22 220 Restricted areas 220 2,200 Protective clothing worn only in restricted areas 220 2,200
- Personnel Monitoring
Personnel dosimeters will be provided to persons authorized to work with radioactive materials at the discretion of the RSO. The dosimeters will be obtained from NVLAP approved dosimetry vendor. It shall be the responsibility of each individual to wear the prescribed personnel monitoring devices during all work with sources of ionizing radiation and to ensure that samples for bioassay are submitted when requested by the RSO.
- Request for Issue of Personal Dosimetry
Upon assignment of duties which will require work with sources of ionizing radiation, CUA personnel not currently equipped with dosimetry shall complete and submit to the RSO a "Request for Issue of Personal Dosimetry" on form RSO-6 (Appendix B)). Authorization to perform such work shall not be granted until the personnel affected are in possession of personal dosimetry.
- Prior Occupational Dose
Personnel issued dosimetry at CUA shall either provide or assist the RSO in obtaining, records of occupational exposure received at other facilities. Individuals exposed at other facilities but not in possession of current exposure records, shall complete and submit form RSO-7 "Request for Occupational Exposure Records" (Appendix B). Individuals who have not received any prior occupational exposure shall provide a written statement to that effect on the same form.
- Temporary Personnel and Visitor Dosimetry
Temporary personnel assigned radiological work for periods of one quarter or less and Visitors requiring escort into a restricted area at CUA, shall be issued one of the numbered Visitor film badges stored with the Visitor Film Badge Logbook. At the time of issue, the person receiving dosimetry shall ensure that the following required information is legibly entered into the logbook:
- the temporarily assigned person's or Visitor's full name;
- Social Security number;
- date of birth;
- current mailing address;
- date that dosimetry was issued; and
- escort's name.
"Survey" is defined to mean measurement of levels of radiation exposure (dose rate) or concentrations of radioactive materials present in uncontrolled form and disposition (contamination).
"Unsealed container" is defined to mean any container of radioactive material which is open to the atmosphere or which can be opened.
- Authorized User Responsibility for Surveys
The responsible Authorized User shall ensure that each room in which unsealed containers of radioactive material totaling in excess of 1 millicurie are used or stored is surveyed at least weekly, and daily when procedures using unsealed sources in excess of 1 mCi are performed. Wipe tests shall be used for carbon-14 and tritium. (Clean wipes are available from the RSO.) The results of User surveys shall be recorded in a suitable chronological log for each affected area, which shall indicate the areas surveyed, the level of removable contamination measured (dpm/100 cm2) and the isotope most likely to be present.
- RSO Responsibility for Surveys
The RSO shall ensure that wipe tests and/or meter surveys, independent of those conducted by Users, are performed in all CUA controlled and restricted areas once per month. Special projects or campaigns may be monitored more frequently. The results of these surveys shall be made a permanent part of the records of the RSO.
- Requirement for Decontamination Efforts
When a meter survey indicates a radiation exposure rate greater than twice background, in the absence of known sources, that area shall be considered contaminated and a wipe test shall be made to determine the extent of the removable contamination. Decontamination efforts shall be undertaken when removable activity is found to exceed 50% of the limits stated in Table 22.214.171.124; good practice dictates that decontamination efforts should be undertaken as soon as practicable whenever removable contamination is demonstrated to be present.
- Survey Instruments
In conjunction with Section 126.96.36.199, the RSO shall assure that appropriate survey instrumentation is available to each laboratory in which radioactive materials, other than tritium, are used.
Survey instruments shall be calibrated at least annually. Each meter calibrated shall bear a label indicating the date of last calibration, the date calibration is next due, and any conversion factors. The RSO shall provide or arrange for calibration service.
The RSO is responsible for maintenance and repair of all CUA-owned radiation protection instruments.
- Labeling Containers Of Radioactive Material
Each container of radioactive material shall bear a durable, clearly visible label bearing the radiation caution symbol, the words "CAUTION RADIOACTIVE MATERIAL", and where it is necessary to avoid or minimize exposure, sufficient information such as radionuclide present, quantity, radiation levels and date. In addition, the RMIC number shall be affixed in accordance with Section 188.8.131.52.b.
Appropriate labels will be supplied by the RSO.
The RSO will advise when certain exceptions to the labeling requirement may be appropriate.
- Storage Of Radioactive Material
Licensed material shall be stored only in controlled or restricted areas and in a manner which provides adequate protection against fire, explosion, flooding or unauthorized removal. Such radioactive material shall be stored in suitable containers and direct radiation (beta/gamma) from the container shall be limited by shielding in accordance with Section 9.3.9.
- Shielding Sources Of Ionizing Radiation
All sources of ionizing radiation, including stock materials, in a restricted area shall be shielded so that the dose rate shall not exceed 10 mrem/hr (100 µSv/hr) at any exposed surface of the container or shield, or 5 mrem/hr (50 µSv/hr) at 30 centimeters from any exposed surface of the container or shield. The exposure rate in the nearest unrestricted area accessible to personnel shall not exceed 0.5 mrem/hr (5 µSv/hr).
- Radioactive Waste
Radwaste shall be stored and disposed of only in accordance with the detailed procedures set forth in Appendix D of this manual.
- Misplacement, Loss, Or Theft Of Radioactive Material
Discovery of the misplacement, loss, or theft of radioactive material shall be reported promptly to the RSO, who shall be guided by applicable regulations in notifying appropriate authorities.
- Equipment Used For Radioactive Work
- Removal of Equipment from Controlled or Restricted Areas
Equipment which has been used with radioactive material, or which may have become contaminated by radioactive material, shall not be removed from a controlled or restricted area to an unrestricted area (e.g., repair shop, machine shop, other laboratory, cleaning facility or returned to vendor) until demonstrated to be free of contamination in accordance with Table 184.108.40.206.
Surface contamination limits for unrestricted equipment release
U-nat, U-235, and associated decay products 5,000 15,000 1,000 Transuranics, Ra-226, Ra-228, Th-230, Th-228, Pa-231, Ac-227, I-125, I-129 100 300 200 Th-nat, Th-232, Sr-90, Ra-223, Ra-224, U-232, I-126, I-131, I-133 1,000 3,000 200 Beta-gamma emitters (nuclides with decay modes other than alpha emission or spontaneous fission) except Sr-90 and others noted above. 5,000 15,000 1,000
- Repair of Contaminated Equipment
Equipment to be repaired or modified on site in a restricted area by University or contractor personnel shall be decontaminated, if practicable, prior to servicing. If decontamination to the levels prescribed in Table 220.127.116.11 is not practicable and the repair or modification is warranted by the value of the equipment, the work shall be directly supervised by the Authorized User and/or RSO who shall ensure that appropriate precautions are taken for the radiological safety of CUA personnel.
- Vacuum Systems
Vacuum lines which are built into fume hoods or which discharge into a central vacuum system shall not be used for procedures in which radioactive material could be drawn into the line. A separate vacuum pump exhausting into a fume hood which has been approved for use with radioactive materials shall be used instead; a pump exhaust filter may be required. A pump, once so-used, shall be considered contaminated, and so-labeled, until demonstrated otherwise.
- Radiation-Producing Machines and Equipment
Radiation-producing machines (RPM) and radiation producing equipment (RPE) are defined as any machine or equipment whose primary purpose is to produce ionizing radiation, or which produces ionizing radiation coincidental to its primary purpose. Exposure from RPM and RPE must not exceed a dose equivalent in excess of 5 mrem (0.05 mSv) in one hour at 5 centimeters from any surface of the machine or equipment.
- Exemption from Regulation
Equipment is not subject to these rules if the production of ionizing radiation is not a primary purpose and the exposure does not exceed 0.5 mrem/hr (5 µSv/hr) at 5 centimeters from any accessible surface.
- RSO Responsibility and Authority
The RSO shall be permitted access to radiation-producing equipment for the purpose of inspection and survey. The RSO shall:
- Survey each RPM at its initial testing and at subsequent intervals not to exceed one year. Annual re-survey is not required if the machine is not in use, but a survey shall be conducted at the first resumption of operation.
- Establish safety restrictions on the use of each RPM for the protection of operating personnel and the public. (Should the principal Authorized User believe that RSO-established restrictions are too strict, a review by the RSC may be requested; the written request shall be addressed to the RSC Chair).
- Conduct an orientation lecture concerning the hazards and safety precautions associated with the use of each type of RPM which shall be attended by each individual authorized to operate the equipment without direct supervision.
- Halt the use of any RPM should operation pose an unreasonable radiation hazard.
- Report to the RSC any violation of safety restrictions or general safety rules specified in Section 18.104.22.168.
- General Safety Rules for RPE
Radiation-producing equipment (RPE) shall be operated only by designated personnel. Designated personnel are defined as "Principal Users" or "technicians". Qualifications of Principal Users shall be submitted to the RSC for approval on Form RSO-4 "Qualifications of Principal Users of Radiation-Producing Machines" (Appendix B). Qualifications of technicians shall be evaluated and approved by a Principal User and written notification of this qualification shall be on file with the RSC and the RSO. Technicians shall operate radiation-producing machines under the supervision of a Principal User. Students and others who use RPE as part of a regularly scheduled course or on a very infrequent basis are exempt from the requirement of registration with the RSC, provided that such operation is conducted under the direct supervision of a Principal User. All RPE shall be operated in accordance with the following provisions:
Areas in which RPE is located or is being used shall be posted with the characteristic "Caution (or Danger) Radiation" or "Caution (or Danger) X-rays" sign to warn unauthorized personnel from entering the controlled area. The controls for each RPM shall have a decal stating "Caution (or Danger) Radiation - This Machine Produces Radiation When Energized." In certain instances, other precautions such as locking room entrances, locking the machine controls, or the use of automatic safety devices may be required by the RSC.
Radiation-producing equipment shall not be operated without the presence of the RSO if it has not been operated for more than one year.
Portable radiation-producing machines shall not be operated at locations outside the laboratory where the machine has been surveyed without the prior approval of the RSO.
When not in use, each radiation-producing machine shall be either disconnected from its power source or locked to preclude operation by unauthorized personnel.
Before operating the machine the operator shall clear the area in the direction of the primary beam of all personnel.
Personnel monitoring devices shall be worn by the operator and all others present during operation of any machine which is capable of creating an exposure field in excess of 2 mrem/hr (20 µSv/hr) at any accessible location.
The operator shall never expose himself or others to the direct beam of the machine and must not enter an exposure or target room while a machine is in operation unless adequately shielded.
All incidents involving radiation levels in excess of those authorized or anticipated, or possible exposures of personnel, shall be reported immediately to the RSO.
A primary beam shall not be directed towards an interior wall, ceiling or floor in the absence of approved primary beam shielding.
The structural shielding requirements for any new installation or for an existing installation must be approved by the RSC.
- All operating personnel shall observe all restrictions, established by the RSO or RSC, on the use of RPE. They shall bring to the attention of the RSO discovery of a potentially hazardous mode of operation which has not been anticipated by such restrictions.
- Use Of Radioactive Material In Animals
Radioactive material shall not be used in experimental animals without the approval of the RSC. The RSO shall also be advised before starting work.
- The use of animals for experimental purposes shall be consistent with current Department of Health and Human Services guidelines.
- Responsibilities Of Authorized Users
With respect to radiological safety, the primary responsibility of Authorized Users is to ensure that radiation exposure to themselves, to individual users for whom they have radiological safety oversight, and to the public, is maintained both within the limits prescribed in this manual, and as low as is reasonably achievable (ALARA). To this end they shall:
Be familiar with, comply with, and require compliance by others with, the instructions in this manual and their authorizations for use of sources of ionizing radiation.
Plan adequately for experiments and emergencies, consulting the RSO when appropriate.
Teach (by instruction and example) those for whose radiological safety they have oversight the use of safe techniques and the application of approved radiation safety practices (the RSO will conduct or assist in such instruction on request).
Ensure that appropriate radiation survey and monitoring equipment is available and used, and that it is functional and calibrated when due.
Ensure that appropriate protective equipment (e.g., shielding, exhaust hoods and filters, glove boxes, etc.) is available and properly used and maintained.
Maintain a current record of the receipt and disposition of radioactive material charged to them.
Limit the use of radioactive material and sources of ionizing radiation for which they are responsible, to individuals over whom they have supervisory control and to locations specified in their User Authorizations, and ensure that no unauthorized use is made thereof.
Allow only authorized persons to enter rooms specified as restricted areas.
- Inform the RSO immediately if any of the following circumstances are suspected:
- Any incident that causes or threatens to cause exposure to a member of the public.
- Inhalation, ingestion or injection of radioactive material by any person.
- Accidental spill of radioactive material, or release of radioactive material to the atmosphere, drain, or ventilation system.
- Inform the RSO, in a timely manner, when:
- It becomes necessary to delegate their responsibilities to another qualified individual (i.e., due to a protracted absence from the University).
- The Authorized User or a radiation worker under the Authorized User's supervision has declared she is pregnant.
- Changes are anticipated in the work under the Authorized User's supervision which may increase the probability or extent of exposure to ionizing radiation.
- Changes are anticipated in personnel working with sources of ionizing radiation.
- Provide notification to the RSO of any changes regarding rooms in which radioactive material is stored or used, or in which radiation-producing equipment is used.
- Provide an up-to-date list to the RSO of personnel who may be handling radioactive material. Students whose only handling of radioactive material occurs incidental to a regularly scheduled class need not be individually named on the required list.
- Responsibilities Of Individual Users
"Individual User" is defined to mean any person who works with sources of ionizing radiation under the supervision of an Authorized User.
Individual Users shall conduct their operations so as to maintain the radiation exposure of themselves and others as low as is reasonably achievable (ALARA). To this end they shall:
- Understand and comply with the work habits prescribed in Section 9.3.17, and the instructions received from the Authorized User to whom they are responsible.
- Wear prescribed personnel monitoring equipment and protective clothing during all work with or in the vicinity of sources of ionizing radiation.
- Consult the Authorized User to whom they are responsible BEFORE PROCEEDING if they have any doubt about the correctness or safety of an intended procedure.
- Inform the responsible Authorized User and/or the RSO immediately if any of the following circumstances is known or suspected:
- Any incident that causes or threatens to cause exposure to a member of the public.
- Inhalation, ingestion or injection of radioactive material by any person.
- Accidental spill of radioactive material or release of radioactive material to the atmosphere, drain, or ventilation system.
- Keep accurate records of the use and disposal of radioactive material transferred to them.
- Make no unauthorized use, transfer, or disposition of radioactive material.
- Work Habits
Before any work is undertaken with radioactive material, attention shall be given to precautionary measures, including the use and adequacy of hoods, filters, and remote handling equipment. The RSO shall be consulted on specific operations which could deviate from previously authorized procedures.
- Protective Clothing
Suitable gloves shall be worn during all work with unsealed radioactive material. Dispose of gloves to radwaste after use. Protective glasses or goggles shall be worn if there is a possibility of contamination of the eyes.
INDIVIDUALS WITH OPEN SORES/CUTS ON THEIR HANDS, WITH OR WITHOUT BANDAGES, ARE NOT AUTHORIZED TO WORK WITH UNSEALED RADIOACTIVE MATERIALS
Additional protective clothing, such as laboratory coats, coveralls, rubber aprons, and shoe covers, shall be worn whenever contamination of clothing with radioactive material is possible, as appropriate. Protective clothing shall not be worn or taken out of the local areas in which its use is required unless surveyed and found to be free of contamination. Under no conditions may protective clothing be worn in eating places.
- Materials Handling
- Prior to performing an operation on or with a source of ionizing radiation, radiation levels shall be measured. Remote handling tools, such as forceps and tongs, shall be used for handling a source which causes an exposure, at contact, in excess of 50 mrem/hr (500 µSv/hr).
- When working with a source of ionizing radiation which emits penetrating radiation of sufficient intensity to produce significant exposure, a survey meter shall be used to monitor work in progress to confirm the adequacy of shielding or remote handling tools.
- Approved exhaust ventilation shall be used when performing operations which might produce airborne contamination (e.g., evaporation, sanding or grinding, transfers of unsealed powder or volatile radioactive material, etc.). Approved exhaust ventilation means a hood, glove box, or local exhaust facility which has been approved for work with radioactive materials. Approved facilities shall be so-designated by printed labels attached to the ventilation unit.
- Work which can result in contamination of work surfaces shall be done in trays. The choice of tray material will depend on the chemicals to be handled and the ease of decontamination versus disposable trays. Adjacent work surfaces shall be lined with absorbent paper.
- Work areas shall be kept clean and free of equipment and materials not required for the procedures in progress.
- Unsealed radioactive material shall be stored in shatterproof plastic containers when practicable. Additional precautions such as the use of carts or shatterproof protective outer containers shall be taken when transporting glass containers.
- Contaminated equipment and tools (glassware, hot plates, stirrers, hand tools, etc.) shall be appropriately identified and isolated from other equipment if it is to be retained for future use. Once used for radioactive work, such material shall not be removed from a controlled or restricted area until demonstrated to be free of contamination in accordance with Section 22.214.171.124, unless it is packaged and removed as radwaste.
- In order to minimize the risk of contaminating wounds, special care shall be exercised when assembling, disassembling and manipulating contaminated glassware.
- MOUTH PIPETTING OF ANY MATERIAL IS FORBIDDEN. Always use pipetting equipment.
- Do not eat, drink or store food in rooms where radioisotopes are used or where contamination may exist.
- Smoking is prohibited in all laboratory areas.
- Personnel working with radioactive material should wash hands before eating, smoking, or leaving work; they shall make hand and shoe surveys, when appropriate, prior to leaving a controlled or restricted area where operations with unsealed sources are conducted.
- Food, drink and photographic film shall not be stored in a refrigerator used for storage of radioactive material.
- Keep fingernails trimmed to minimize the likelihood of puncturing protective gloves.
- In the course of working with unsealed radioactive material, if personal contamination is suspected, stop work and survey with a suitable instrument. This shall be followed by any required decontamination and a further survey.
IF CONTAMINATION IS SUSPECTED OR CONFIRMED, DO NOT LEAVE THE AREA. NOTIFY YOUR AUTHORIZED USER, THE RSO, OR THE DEPARTMENT OF ENVIRONMENTAL HEALTH & SAFETY.