Exposure control, radiation engineered controls

There are several types of engineering controls to limit dangerous exposures to radiation. Controls include limiting radiation emissions at the source, limiting time of exposure, extending the distance from a source, and shielding. Certain other controls will also help prevent dangerous exposures. 

One of the most important aspects of radiation protection requirements, and one that distinguishes them from other personnel safety requirements required by Occupational Safety and Health Administration (OSHA), is the concept of ALARA 10 CFR 20.1101 requires that "the licensee shall use, to the extent practicable, procedures, and engineering controls based on sound radiation protection principles to achieve occupational doses and doses to members of the public that are ALARA." This is in sharp contrast to most OSHA standards where it is acceptable to allow exposures, such as breathing air concentrations of contaminants, to go right up to the limit as long as that limit is not exceeded. 

Administrative and Engineering Controis The use of administrative and engineering controls is essential for keeping radiation exposure ALARA. 

Differential thermal analysis was performed with the DuPont 900 differential thermal analyzer the heating rate was usually 10°C. per minute. To determine heats of reaction, the calorimeter attachment to the Du Pont instrument was employed. Planimeter determinations of peak areas were converted to heat values by using standard calibration curves. For the infrared spectra either a Beckman IR5A instrument or a Perkin Elmer 521 spectrophotometer with a Barnes Engineering temperature-controlled chamber, maintained dry, was used. Specimens for infrared were examined, respectively, as Nujol mulls on a NaCl prism or as finely divided powders, sandwiched between two AgCl plates. For x-ray diffraction studies, the acid-soap samples were enclosed in a fine capillary. Exposures were 1.5 hours in standard Norelco equipment with Cu Ko radiation. For powder patterns the specimen-to-film distance was 57.3 mm. and, for long-spacing determinations, 156 mm. 

In Jime 2004 with authorization of the Main Technical Department of the Russian Navy specialists of Expert-center Research and Engineering Office together with NIKIET performed a detailed radiation examination inside and outside all compartments (save for RC) of NSs 175 and 610 in compliance with a specially-developed and approved program. Dose control and spectrometric measurements allowed revealing the following maximal exposure dose rates were measured in adjacent-to-RC compartments on bulkheads from RC side (0.1-0.38 mSv/h for NS 175 and 0.83-0.9 mSv/h for NS 610). 

The contractor s implementation plan indicated that SRS complies with the Order, which states that radiation exposure rates in controlled workplace areas should be reduced to ALARA levels by facility design and control. The Order states that the primary means are to be through physical controls with reliance on administrative and procedural means to be considered only as supplemental measures. After a review of DPSOP-40, a draft of the new Radiological Controls Manual - 5Q, Section RC-lOOl, "Design of New Nuclear Facilities (Reference 32), and several memoranda (References 33-36 between and within WSRC s Health Protection Department and Engineering and Projects Division, DOE has concluded that the programs in place indicate that the contractor is In compliance with the requirements of this section of the Order. 

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