Views:269 Author:Site Editor Publish Time: 2020-08-28 Origin:Site
In modern life, people are exposed to radiation everywhere. What is the relationship between radiation and health? Will the radiation of self-luminous products harm human health? Radiation exposure standards are specified in AR 40-14. There standards have been established by DA for the control of occupational exposures to ionizing radiation and radioactive material. Alternate radiation exposure standards, less restrictive than those prescribed above, many be used in special circumstances when approved by The Surgeon General. Proposals for the use of alternate standards shall contain complete justification and should describe the means by which the standards shall contain complete justification and should describe the means by which the standard shall be implemented.
No individual under 18 years of age shall be occupationally exposed to ionizing radiation in excess of that allowed to any individual in the population at large. An authorized and appropriate personnel monitoring device shall be sued to measure the exposure of each individual who is likely to receive an accumulated dose equivalent of ionizing radiation in excess of 5 percent of the applicable annual basis radiation exposures the individual may receive during that calendar quarter. The primary dosimetric device fro DA is the film badge.
Radiation surveys are performed to indicate the general level of radiation in the controlled area and to provide information on changing levels of radiation or radioactive contamination as work progresses. The measurements of radiation levels and radioactive contamination shall be made at periodic intervals during the conduct of the work, particularly when conditions change drastically (such as when source containers are opened, or radioactive material is transferred from one area to another or from one vessel to another).
A dry wipe may remove anything from 0 to 100 percent of the radioactive contamination present but, generally, a removal factor of 10 percent shall be assumed. Therefore, by applying this removal factor of 10 percent, the approximate amount of transferable radioactive contamination on the surface can be estimated. The removal factor is greater when a wet wipe technique is employed. The liquid chosen to moisten the filter paper shall not chemically react with the surface to be monitored, but should be effective in removing the radioactive contamination. The wet filter paper must dry before monitoring for alpha and low energy beta activity.
Every individual who handles or uses radioactive materials or exit sign with emergency light devices shall be monitored prior to leaving the work are. Any evidence of radioactive contamination above the levels in AR 385-11 shall require decontamination. Hands, skin, and nails shall be cleaned and scrubbed. Monitoring for alpha emitters should be accomplished with proportional or scintillation-type detector instrument. For beta-gamma emitters except tritium, a Geiger-Mueller instrument, with a certain window detector or a gas flow proportional detector should be used for monitoring. The scale on the G-M instrument shall not read over 0.5 mill roentgen per hour and corresponding count per minute full scale on the lowest scale. The skin shall be thoroughly washed until repeated washings do not lower the exposure of count rate or until no radioactivity above natural background is detected. If a reduction of exposure of count rate is not indicated following these washings, further decontamination shall be accomplished in accordance with the recommendations contained in NCRP report No.8 and 59 under local RPO and medical supervision.