Document 93B3Vq9L2B7nwzezyq7YmZ1bq

IONIZING RADIATION ah were involved The worst cases are now described by category. External radiation exposure of personnel Accidents occurring in atomic energy op erations in this country during the 20-year period 1943-1962, which includes the AEC predecessor, die Manhattan Engineer Dis trict, may be divided into three groups (1) those In no way unique to the use of atomic energy or its products, such as falls, electrocutions, and motor vehicle accidents; (2) those involving radioactive matenah, such as fires, explosions, and environmental contaminations, and (3) those resulting in radiation exposure to workers. During that period, there were a total of 239 fatalities resulting from the three groups of accidents, six of which were from accidents directly attributable to nu clear causes. The fetal injuries of three men at Los Alamos were attributed to the direct result of exposure in early experi mental work to a massive dose of nuclear radiation The immediate cause of the three remain ing fatabties was the effect of blast and flying missiles associated with the SL-1 nuclear accident on January 3, 1961, where the radiation levels associated with that accident were also extremely high and prob ably would have been fatal Duong this 20-year period in atomic en ergy operations, there were 7,081 lost time injuries of all kinds (as defined in American Standards Association Method of Record ing and Measuring Work Injury Experi ence, ASA Z161) attributable to aU acci dental causes. This was the experience of 300,300,898 man-days of potential accident exposure, which produced over two billion man-hours of work. Only 35 of the 7,081 lost time injuries (approximately 06%) were caused by nuclear radiation which gives a 0 017 frequency rate (number of in juries per million man-hours). In some cases of no injury, time was lost for medi cal study. It is interesting to note that the AECs overall industrial accident experience has always been much lower than the aD-mdustry rate reported by 42 industries In the United States to the National Safety Coun cil The annual average frequency rate for 1962 for NSC was 619 (for all disabilities. 11,998 units reporting) compared with 197 for AEC in 1962. Such occurrences should even be less than the AEC figure for general industrial utilization of radioactive materials because they are possible only when critical quanti ties of fissionable materials are being proc essed Therefore, they are more likely to occur in scientific investigations than in in dustrial operations with established produc tion methods for work with radioactive materials Internal radiation exposure of personnel A hue must he drawn to distinguish trivial exposure values from significant ex posure values. If die "permissible body burden" for an extended period of tune is taken as the criterion, there have been per haps a dozen or so cases so far reported If the criterion is the appearance of the radioisotopes m the excreta of the exposed person at a level that may possibly lead to clinically observable health defects, the num ber of such cases is insignificant Some of the basic data on which all in ternal permissible levels depend is being fur ther refined Precise evaluation of internal body burdens from excretion data or from whole body counting is possible in many instances There have been some cases of inhalation of radioactive material and also cases of absorption of radioactive material through skm broken by an abrasion or cut In some instances, materials contaminated with ra dioactivity have become imbedded m the body of die injured person at the tune of an explosion from either chemical or nuclear ongm, and here the serious injury was from the explosion rather than from the radio activity. Inhalation of contaminated air is a more serious cause -of internal exposure than is the drinking or eating of material that has been radioacbvely contaminated on the job Fortunately, such occurrences are relatively rare due to a high level of planning and close control of operations In contrast to this experience, watch dial pamterg in for eign countries will probably continue to de velop radium poisoning Contamination of personnel The probability of contamination of both 42-18