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KAUST aims to prevent unnecessary radiation exposures to individuals and the environment, and to keep radiation exposures to employees, members of the public and the environment ALARA. The ALARA principles attempt to maintain exposures to radiation below the dose limits, consistent with the purpose for which the exposure is generated, but also taking into consideration the state of technology, the cost of the improvements needed to reduce the radiation exposure, and the benefits to public health and safety. As part of the ALARA program at KAUST, individuals who are less than 18 years old are not allowed to work with sources of ionizing radiation in Supervised or Controlled Areas and their radiation doses are equivalent to that of members of the public (see Table 4). Two basic conditions are considered necessary in any Radiation Safety Program for keeping occupational and public exposures ALARA:
Radiation exposures to individuals working in Controlled or Supervised Areas (i.e. classified and non-classified radiation workers) are considered “occupational” exposures. The radiation dose in any one calendar year must be kept ALARA and specifically below the primary dose limit set by the Competent Authority (NRRC), see Table 1. In addition, radiation workers’ doses should not exceed the dose constraint levels set by KAUST. The dose constraint level is not intended to be an absolute limit but to provide guidelines for keeping exposures ALARA. If the constraint dose levels are exceeded, an investigation by the RSO will be carried out and reported to the IRSC, and if necessary to the Competent Authority (NRRC). The investigation includes a dose estimation, and a review of the radiation safety measures to determine whether additional safety measures are required.
Table 1. Annual Occupational dose limits and Dose Constraints levels for individuals working at KAUST
| Occupational Annual Dose Limit (mSv/y) | Annual Doses above which classification would be necessary (mSv/y) | KAUST Dose Constraints1 | |
|---|---|---|---|
| Whole Body | 20 (100 mSv/5y) | 6 | 2 mSv/year |
| Lens of the eye | 20 | 15 | 15 mSv/year |
| Skin or Extremities (hands and forearms, feet and ankles) | 500 | 150 | 50 mSv/year |
General public dose limits apply to members of the general public, peripheral workers, ancillary staff, and visitors. In addition, individuals working in Non-Designated Areas (i.e., non-classified workers) are also subjected to the general public dose limits since radiation-producing equipment used in these areas are not regulated by NRRC and considered safe (i.e., no exposure to significant radiation levels expected). All activities must be done in a manner that limits the exposure of these staff members as well as the general public to the regulatory limits for members of the public specified in Table 2. As for public doses, if the NRRC dose levels are exceeded an investigation by the RSO will be carried out and reported to the IRSC and if necessary to the Competent Authority.
Table 1. Annual Occupational dose limits and Dose Constraints levels for individuals working at KAUST
| Public dose limits set by NRRC | |
|---|---|
| Whole Body | 1 mSv/year |
| Lens of the eye | 15 mSv |
| Skin or Extremities (hands and forearms, feet and ankles) | 50 mSv |
Any female radiation worker who is pregnant or believes that she may be pregnant should inform the RUA holder and/or the RSO as soon as possible. Although declaration of pregnancy is voluntary and all information relating to the pregnancy is strictly confidential, concerns about fetal exposure can only be addressed if known. Any female who is occupationally exposed to radiation resulting from research activities may declare her pregnancy and institute the enhanced protective measures by completing and submitting the Pregnancy Declaration Form. If a written declaration of pregnancy is not submitted, then the worker’s dose continues to be controlled under the normal dose limits for workers with ionizing radiation.
The dose limit to an embryo/fetus due to occupational exposure is 1 mSv from the declaration of pregnancy to the employer.
The RSO may be asked to review the declared pregnant woman’s potential exposures, and this may result in work modifications or temporary termination of work involving occupational radiation exposure after consulting with the affected woman’s supervisor, and/or the assignment of special dosimetry. However, for the type of radiation work performed at the KAUST, it is rarely necessary to recommend reassignment or changes to job duties to reduce exposure. Additionally, the RSO is available to answer any questions users may have. All inquiries and information are kept strictly confidential.
The NRRC regulations requires personnel exposure monitoring for the following:
The amount of cumulative external radiation that a person has been exposed to can be determined using a wide variety of devices and materials. All of these are referred to as "dosimeters." Dosimeters are provided to track exposures to the extremities as well as the entire body. Dosimeters are quarterly swapped out by the RSO and sent to the vendor's laboratory for analysis. The Radiation Safety Officer will determine if badges are required following a risk assessment of the user’s work scenario relative to radiation source use, and the likelihood of that individual receiving an occupational dose in excess of dosimetry requirements by the Nuclear and Radiological Regulatory Commission (NRRC).
Based on the RSO’s review, dosimetry requirements are determined and are indicated in the Local Rules. There are generally two types of external dosimetry:
When not being worn, dosimeters must be stored in a location where they are not exposed to radiation. Dosimetry will be provided and processed only by vendors accredited by the Competent Authority.
Internal radiation dose occurs if radioactive substances are inhaled, ingested, injected, absorbed through wounds, or absorbed through the skin. Protective clothing and other measures must be used to prevent or reduce internal radiation dose.
The IRSC must review each RUA application before work can begin. One aspect of the IRSC’s review is to determine the potential for internal exposure. The RSO determines what, if any, controls (such as use of a fume hood) are required and the need for bioassays. All these requirements must be included in the Local Rules. However, considering the quantities and activities of radioactive substances currently used in the laboratory, routine bioassays will not be necessary.
All exposure monitoring results are reviewed by the RSO to ensure that regulatory dose limits (also called primary dose limits) and accepted dose constraint levels are not exceeded and that exposures are consistent with the ALARA principles. Any occupational exposures greater than the KAUST dose constraint levels require investigation.
For general public exposure, any exposure greater than the NRRC public dose levels also require investigation.
If an individual's radiation exposure exceeds the accepted levels, he/she and the RUA holder must be notified in writing of the nature and extent of their exposure. In addition, all personal monitoring results are kept by HSE for 30 years or until the person reaches 75 years of age (whichever comes last) as requested by NRRC.
In the case of known or suspected overexposures, the RSO must notify the Competent Authority (NRRC). The RSO and IRSC may recommend the individual to undergo medical evaluation and/or treatment by a qualified physician.
At any time, personnel may request a summary report of the doses received while working on KAUST research spaces. To protect confidentiality, the request must be written and signed by the person asking for the report and submitted to the RSO for action.
Please contact the RSO to check if you are eligiable for receiving a personal dosimeter.
Portable radiation survey meters used at KAUST for quantitative radiation measurements are calibrated annually as required by the Nuclear and Radiological Regulatory commission (NRRC). The Radiation Safety Officer performs such calibrations with an accredited service provider across a wide range of radiation types and levels.
If your survey meter is due for calibration, please contact the Radiation Safety Officer athse@kaust.edu.sa for assistance. The RSO will assist you in filling calibration service form and shipping your instrument for calibration.
