PERSONAL RADIATION

I I jealllivewithradiatioRltwas I I I in our environment well before the discovery of the atom and even before the first human civiliza- 

Enter value for altitude of location where you live Sea level = 30 mrem 500 m (1650 ft) = 3S mrem 1000 m (3300 ft) = 40 mrem 2000 m (6600 ft) = 60 mrem Airline travel Hours you fly each year x 0.6 mrem 

X rays = 20 mrem per visit Gastrointestinal X rays = 200 mrem per visit Dental X rays = io mrem per visit Radiation therapy (ask your radiologist) 

If you live withiii 50 miles of a nuclear power plant, add 0.009 tnrem 

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BS3664 Film badges for personal radiation monitoring. 

A watt is a measure of power (the rate of energy change) equal to 1 J/s. (a) Calculate the number of joules in a kilowatt-hour, (b) An adult person radiates heat to the surrounding at about the same rate as a 100-watt electric incandescent lightbulb. What is the total amount of energy in kcal radiated to the surroundings by an adult in 24 hours ... 

Nuclear medicine facihties also represent a special hazard. Normally, nuclear injections use a short-hved isotope Tc with a halfhfe of a little over 6 hours. If the injection is in a large animal, such as a horse, the personnel exposure level can be substantial and workers should be provided with personal radiation monitors. Collection of the feces and urine may be required. In addition, the animal may not be released to a member of the pubhc until the exposure levels fall below the legal limits for unmonitored persons (more on this later). X-rays of animals also represent a special hazard since one cannot simply teU an animal to hold still. Often taking of x-rays will require a person to hold the animal stiU. Holders wUl often receive substantial levels of scattered x-ray radiation so this duty should be spread among a number of individuals. 

Figure 5.10 Film badge for personal radiation monitoring. The various areas shown on the front of the badge provide for information to be obtained about the radiation reaching the frlm. The open " area may be covered with a a very thin mylar film which will allow betas to be detected in that aaea. 

Personal radiation Early warning device to warn field personnel and first Geiger-Muller counter... 

Personal radiation exposure can be measured using a film badge, which is worn by the employee over a fixed time interval. The badge contains a photographic film which, after the time interval, is developed and an estimate of radiation exposure is made. A similar device, known as a radiation dose meter or detector, can be positioned on a shelf in the workplace for three months, so that a mean value of radiation levels may be measured. Instantaneous radiation values can be obtained from portable hand-held instruments, known as geiger counters, which continuously sample the air for radiation levels. Similar devices are available to measure radon levels. 

Ten years passed since the biggest radioactive catastrophe in the history of humanity happened at the Chernobyl nuclear power plant. The Russian State medical dosimetric Register was founded after this catastrophe At present in the Register they keep a medical and radiation-dosimetric information about 435.276 persons. 

Radiation dose limits at a disposal site boundary are specified by the NRC as 25 x 10 Sv/yr (25 mrem/yr), a small fraction of the average radiation exposure of a person in the United States of 360 x 10 /Sv/yr (360 mrem/yr). Protection against nuclear radiation is fully described elsewhere... 

The role of cytokine therapy in the management of radiation accident victims has been summarized (152). In GoiBnia in Brazil in 1987, eight radiation accident victims were treated with GM-CSF one month after radiation exposure. Marked increases in granulocyte production were induced in five persons, although this did not prevent death. 

Conduct a risk assessment to any employee and other persons to identify measures needed to restrict exposure to ionizing radiation and to assess magnitude of risk including identifiable accidents. 

L 58 Approved Code of Practice - The Protection of persons against ionizing radiation ansmg from any work... 

Erickson, J., Zimmermann, E., Southwick, J. and Kiibler. K., Adhes. Age, Nov. (1995). Charlesby, R., Atomic Radiation and Polymers. Pergamon Press, New York, I960, p. 467. Pappas, S.P., Radiation curing a personal perspective. In Pappas, S.P. (Ed.), Radiation Curing Science and Technology. Plenum Press, New York, 1992, p. I. 

The ground flare shall not exceed radiation level of 500 BTU/hr ft at third persons of the radius of 500 ft, excluding solar radiation. 

Answer The automobile death rate is about lE-7/passenger mile. If 25,000 people evacuate 20 miles, this is 5E5 passenger miles, hence, the risk is 5E5 IE-7 = 0.05 deaths. The radiation exposure is 2.5E4 5E-4 48 = 600 person-rem. Using information from problem 4, the estimated deaths from radiation is 600 lE-4 = 0.06. About the same. The risk from radiation may be over estimated because the radiation level was measured close to the plant on the other hand, the traffic fatality estimate may be high because of police presence and slow driving. 

Radiation sensor fails Fail to detect critical condition and fails to initiate bed separation High Redundant detectors are used. In addition technicians have personal audible (cherper) nioniioi s to alert to an incipient critical condition. 

In buildings away from outside perimeter walls, air and surface temperatures are usually approximately equal. The heat losses from a person by radiation (q ) and convection (q ) are then flowing to the same temperature level. In such uniform spaces, the radiant and convective losses are about equal and together account for about 80-90% of the total heat loss of a sedentary comfortable individual. In the presence of hot or cold surfaces, as may occur in perimeter or other locations in a building, the average surface temperature of the surroundings (called mean radiant temperature) as seen by the person s body may be substantially different from air temperature. If the mean radiant temperature (MRT) is greater or less than air temperature (T,) the person will feel warmer or colder than in a thermally uniform space where MRT =. ... 

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