OCCUPATIONAL RADIATION SOURCES

In the case of the LiMg momentum density and occupation number density reconstruction of Stutz et al, who collected 6 x 105 6 counts for Li and 6 x 107 counts for LiMg, this would mean that 6 x 10s—6 x 10 counts per spectrum were required, which hardly can be accomplished in a reasonable amount of time even at modem synchrotron radiation sources. 

Individual dose assessment requires radiological data on all external and internal sources contributing to occupational and non-occupational radiation exposure (Steinhausler and Pohl, 1983). This is of particular importance in the case of low level Rn-d exposure, as man is always exposed to Rn-d at varying levels through all stages of life, e.g. at school, home or work. The resulting lifetime risk from this chronic exposure is influenced by the latent... 

Exposure incurred by members of the public from radiation sources, excluding any occupational or medical exposure and the normal local natural background radiation but including exposure from authorised sources and practices and from intervention situations. 

For whole body exposure, the non-occupational exposure limit is 100 mrem/year. This is in addition to the 360 mrem/yr received, on average, by individuals in the U.S. from natural background radiation and manmade radiation sources. The 100 mrem/year limit also applies to individuals under age 18 who work in the vicinity of radiation sources. 

Personnel monitoring is required when an occupational worker is likely to receive an excess of 10% of the annual dose limit from radiation sources and for individuals entering high or very high radiation areas. Monitoring is accomplished by using film badges or thermoluminiscent dosimeters (TLD). 

For students 16-18 years of age who are required to use radiation sources in their training and studies, the occupational exposure shall be controlled, and the following annual limits must not be exceeded effective dose of 6 mSv, equivalent dose of 50 mSv to the lens of the eye, and equivalent dose of 150 mSv to the extremities or the skin. 

The Agency s standards in the field of radiation protection - the International Basic Safety Standards for Protection against Ionizing Radiation and for the SafeQr of Radiation Sources (BSS) -have been co-sponsored by a number of international organizations and a consensus was reached by the audience they r resent. This is particularly important for obvious reasons. For example, tihe co-sponsorship of the ILO means that these Standards will apply to the conv tion on occupational health the co-sponsorship of WHO means a de facto endorsement of many medical instimtions etc. The BSS co-sponsorship therefore has far-reaching inq>lications. 

Radiation protection during normal operation is a fundamental design consideration for the APIOOO, and it is discussed in detail in the EDCD, Chapter 12 (Reference 12.1). Methods incorporated to minimise occupational radiation exposure include core and fuel design, which minimise fundamental radiation sources operational chemistry, which supports excellent fuel performance purification systems shielding automation and overall simplification of the plant. 

The numerical collective dose target for occupational radiation exposure is 1000 man-mSv/year from all anticipated operational occurrences. Section 12.4 of the EDCD (Reference 12.1) estimates the collective operational dose, including reactor operations and surveillance, routine inspection and maintenance, in-service inspection, special maintenance, waste processing, and refuelling at 219 man-mSv. This dose represents less than 25% of the collective dose target and is a significant improvement on the current UK nuclear power plant average (discussed in Reference Error Reference source not found.). 

In designing a shield for a specific radiation source, the target dose rate should be set, for which account should be taken of the expected frequency and duration of occupancy of the area. Account should also be taken in setting this target dose rate of the uncertainties associated with the source term and with the analysis made to determine the expected dose rate. 

This section should provide a description of the design features of the equipment and the facility that ensure radiation protection. It should provide information on the shielding for each of the radiation sources identified, describe the features for occupational radiation protection, describe the instrumentation for fixed area monitoring of radiation and continuous monitoring of airborne radioactive material, and the criteria for their selection and placement, and address design provisions for any decontamination of equipment, if necessary. 

This Safety Fundamentals publication is a primary publication in the IAEA Safety Series and provides the basis for the requirements in Safety Standards for the control of occupational, public and medical exposures and for the safety of radiation sources. Safety Guides and Safety Practices provide guidance and information on how to implement the requirements. 

Written procedures should be established to ensure that no attempt is made to move the source to its unshielded position when anyone is present in the irradiation room. Administrative controls should be established to prevent unauthorized persons from being in the vicinity of entrances to the irradiation room, including the product carrier entrance. Local rules specifying the procedures to be followed and the precautions to be taken during the operation of the facility should be drawn up and should be provided to all the operators. A combination of engineering and administrative controls should be used to ensure that the desired level of occupational radiation protection is achieved [I-l]. 

Silica [14808-60-7], crystalline (inhaled in the form of quartz or cristobalite from occupational sources) (Vol. 68 1997) Solar radiation (Vol. 55 1992)... 

Many states in the U.S. are currently involved in large scale surveys to measure radon levels in homes in an attempt to assess the environmental risk from radon and radon daughter exposure. Radon daughters deliver the largest radiation exposure to the population and it is estimated that 0.01% of the U.S. population (23,000 persons) are exposed from natural sources to greater than those levels allowed occupationally (4 WLM/yr) (NCRP, 1984). 

The calculation of effective dose equivalent is sometimes used even when reporting values for natural radioactivity. The concept of effective dose equivalent was developed for occupational exposures so that different types of exposure to various organs could be unified in terms of cancer risk. It is highly unlikely that the general population would require summation of risks from several sources of radiation exposure. 

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