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5.0 Radiation Worker Registration and Personnel Dosimetry
Note: The following is excerpted from the full Radiation Safety Handbook
5.1 Registration Requirement
All radiation workers must register with ORS prior to beginning work with any source of ionizing radiation. A radiation worker changing laboratories must re-register prior to commencing work with sources of radiation in the new laboratory.
5.2 New Radiation Worker Packet
ORS provides a New Radiation Worker Packet to each radiation worker. It contains instructions, information concerning risks from occupational radiation exposure, instruction concerning prenatal radiation exposure, and the Radiation Safety Handbook.
5.3 Radiation Worker Registration Form in ISIS
Each radiation worker must view the training video and pass the test with a minimum score of 80% or better before starting the Radiation Worker Registration wizard in ISIS, the Integrated Safety Information System. Based on the answers provided in the wizard, ORS will determine whether personnel dosimetry is required.
5.4 Training Video
New radiation workers must view the training video and pass the associated test unless excused by ORS on the basis of previous training and experience. The video and test is administered through the University’s Course management System (Blackboard). Obtain the new radiation worker packet from ORS and enroll in the video presentation by selecting one or both of two on-line courses: Radioactive Materials Safety Training and X-ray Safety. To enroll, go to the training page at the ORS web site, expand the list of Radiation Safety Training courses, and select one of the two on-line courses, depending on what source of ionizing radiation you intend to use. That link will send you to the HRIS login screen after which you will be able to choose the course offering for your campus. A reply email will provide instructions on how to view the video, take the test and register as a radiation worker.
An email from ORS will provide instructions on how to view the video, take the test and register as a radiation worker. The registration process is not finished until the completed radiation worker registration form is submitted to ORS.
5.5 Posted Radiation Worker List Requirement
Each authorized investigator must post a list of all registered radiation workers under his or her supervision. ORS staff will review the list during surveys and compare it to current records of radiation worker registration. If laboratories are contiguous there is no need to post the list in every laboratory.
5.6 Dosimetry Requirement
Although radiation workers register with ORS, most radiation workers do not wear dosimeters because the potential for significant exposures is very low. The decision whether to issue a dosimeter is based upon the use and form of radiation sources.
IEMA regulations require that the University provide personnel dosimeters to adults likely to receive in one year (from sources external to the body) a dose in excess of 10 percent of the applicable limit. Dosimeters are also required for minors and declared pregnant women likely to receive a dose in excess of 10 percent of their applicable limit.
5.7 Types of Dosimeters
Thermoluminescent dosimeters (TLDs) are the types of dosimeter most widely used. They rely on analysis of a physical change that takes place in the dosimeter when it is exposed to radiation. The body badge consists of a TLD dosimeter in a plastic holder. It is usually used to measure doses to the whole body. A ring or extremity dosimeter is used when more localized exposures are of concern such as irradiation of the hands.
During the radiation worker registration wizard, the worker will select the type of procedures he or she will be performing. Based on the answer to this query, ISIS will determine whether a dosimeter is needed. On the screen labeled Dosimeter Request Form, click the available link to print the form if a dosimeter is required. This completed form must be brought to ORS before a dosimeter can be issued.
5.8 Minimum Reportable Doses
TLD ring dosimeters and body badges have a minimum reporting dose of 10 mrem (0.1 Sv) for X and gamma rays and for energetic beta particles. Readings falling below these levels are recorded on the report as M; M reports are added as zero to the accumulated dose equivalent. A conservative estimate of accumulated dose for M reports would be the product of the appropriate minimum dose times the number of months the dosimeter was worn.
5.9 Control Dosimeters
Control dosimeters are used to measure dose during transit so it can be subtracted from the dose measured while being worn. A control dosimeter comes with each quarterly shipment of dosimeters and each dosimeter delivered separately from the regular shipment. Always return the control dosimeter to ORS along with the dosimeters for which it was issued. Otherwise, the transit doses cannot be corrected for and reports may show doses that were not occupationally received.
5.10 Deep and Shallow Dose
Doses are reported as deep dose or shallow dose. The deep dose pertains to radiation that could penetrate to the blood forming organs (such as bone marrow) or other sensitive tissues. The shallow dose pertains to radiation that affects the skin. The terms deep and shallow dose therefore correspond to the terms "penetrating" and "non-penetrating" dose. The reverse side of the dosimetry report provides detailed information.
5.11 Proper Use of Dosimeters
Dosimeters are not protective devices. They only tell us whether a dose has been received and give some information about it. Dosimetry reports are an aid in evaluating the efficacy of radiation safety measures in a laboratory, class, or clinic, assessing health effects in exposed individuals, revealing accidental exposures, and helping prevent recurring doses. They help keep doses ALARA, but only if they are properly worn and used.
Wear body badges on either a lapel or pocket, and make sure they are visible at all times. Wear ring dosimeters under protective gloves, with the sensitive element on the palm side. Always wear the ring badge on the hand closest to the source. Store dosimeters away from sources of heat and radiation when they are not in use.
If you are interested in the ambient radiation field in your work area, do not use your personal dosimeter to measure it! ORS supplies area monitors for this purpose. Also, never wear another person's dosimeter; the dosimetry report is a permanent, legal record of your occupational dose.
5.12 Instructions to Dosimetry Coordinators
Authorized investigators and registrants should select a dosimetry coordinator who is responsible for receiving and distributing dosimeters for the group, returning used dosimeters to ORS, maintaining dosimetry reports, and handling correspondence with ORS regarding dosimeter orders and billing. If the dosimetry coordinator becomes unable to fulfill the dosimetry program obligations (e.g., because of vacation, illness, or reassignment), the investigator or supervisor should designate another individual to manage the dosimeters and notify ORS of this change.
5.12.1 Location Code
The location code is a two-or-three letter code unique to each research or clinical group. It appears on body badges and ring dosimeter labels, on mailing labels, and on top of service change orders and monthly reports. Please refer to this code when calling or corresponding with ORS about dosimetry matters.
5.12.2 Wear Dates
Most dosimeters are worn for three months, beginning on the 10th of the month. In a few cases dosimeters may be worn for longer or shorter time periods, but the quarterly schedule is the general practice. Dosimeters are issued in January, April, July, , and October.
5.12.3 Distributing Dosimeters
ORS sends dosimeters via campus mail to Investigators or dosimetry coordinators just before the beginning of each wear period. Check the packing list (called the "Service Change Order") and make sure all are accounted for and information is correct. Then distribute the dosimeters to radiation workers.
5.12.4 Collecting DosimetersCollect all used dosimeters on the 10th of the new wear date month. Make sure all are accounted for and mail them to ORS by campus mail or deliver in person. ORS must receive the dosimeters by no later than the 17th of the month. All dosimeters must be accounted for, so you should attach an explanation if any are missing. The investigator will be charged a fee for each lost dosimeter. Mail dosimeters in sealed envelopes to prevent their loss.
5.12.5 Changes in Service
Direct all requests for changes in service to ORS; do not deal directly with the vendor. You may request changes either by phone, e-mail or campus mail.
5.12.6 Temporary Dosimeters
In some cases ORS may issue temporary dosimeters for short-term use while awaiting delivery of the permanent dosimeters. ORS may issue temporary dosimeters if permanent dosimeters become lost. In all cases, the radiation worker shall have met all other requirements for dosimeter use before ORS will issue a temporary dosimeter.
Special dosimeters are available for short courses and classes. ORS keeps only a few temporary dosimeters on hand, so place orders for large numbers of dosimeters well in advance of their intended use. These "special" dosimeters are billed separately from regular dosimeters, so you may need to arrange for separate payment. Your dosimetry coordinator should coordinate distribution and collection of dosimeters and control issuance of registration forms.
ORS bills investigators for the following expenses:
Investigators or dosimetry coordinators must provide a valid chart string to be used for transferring funds.
Exposure reports for the previous wear period will usually be included with the current wear date shipment if the previous wear period dosimeters were returned to ORS on schedule. See the back of the form for detailed information on the analysis, dose limits, and report codes. Authorized investigators and registrants must make dosimetry reports available for viewing by their radiation workers.
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