Operational Accidents and Radiation Exposure Experience Within the U.s. Atomic Energy Commission, 1943 - 1970

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Although these words were penned many years before the establishment of the Atomic Energy Commission (AEC), we feel that they may be paring this publicatkr., 2 is cnly as we are fully;‘ can profit thereby. The protection of persons and gr~p~-r@ against potential hazards in AEC activities ha3 been a fundamental concern of the AEC from the earliest developments in the use of atomic energy. We have simultaneously evolved ’a new technology and a safety program adapted to the AEC’s special purposes. Our continued goal is to develop and utilize this vital national resource to the maximum extent consistent with a high degree of safety. The Atomic Energy Act of 1954, as amended, clearly demonstriatea vital concern with the health and safety of the worker and the public. For example, in section 161(i) of the Act, Congress stipulabd that, in the performance of ita functions, the AEC is authorized to : “prescribe such regulations or orders 88 it may deem necessary. .. (3) to govern any activity authorized pursuant to this Act, including standards and restrictions governing the design, location, and operation of facilities used in the conduct of such activity, in order to protect health and to “The arrangements made pursuant to thia section shall contain such provisions (1) to protect health, (2) to minimize danger all safety and security regulations which may be prescribed by the Commission. ..” From time to the, information ha8 been disseminated pertaining to this subject in AEC publications. However, we have long believed that a publication such as this, centralizing a9 much experience as feasible, would be of help to those interested in the atomic enerw Program. Therefore, in 1966 we gathered available information, descriptions, and statistics regardtaminations, criticalities, fatalities, and property damage accidents, and presented these and Qther relevant data under one cover entitled, srr6 Experience within the United States that the original has been revised on a threeAs in any industrial organization, the AEC’s accident experience falls into two major classifications: (1) that which results in harm to people and (2) that which results in damage of property. However, because of the peculiar (or unique) nature of the atomic industry, both of these classifications must be subdivided into : (1) those occurrences which are not atomic energy-connected and (2) those occurrences which are atomic energy-connected. In a 1956 publication, covering the period 1946-55, it was stated: “By far the most numerous (accidents) are those in no way related t o atomic energy, Falls, electrocutions, motor vehicle accidents, and construction equipment accidents comprise the majority of accidents.” This was not a surprising statement at that time, since so much construction work was in progress during those years. However, it is interesting to note that it is still true, although in the past 16 years, while construction has decreased, the use of atomic energy has greatly increased, and along with this increase, of course, the number of employees in occupations involving potential radiation exposure. In summary, while, because of the AEC’s singular involvement in radiation hazards, we are prone to emphasize those occurrencea resulting in exposures, contaminations, and criticalities, these occurrences are in the minority in the overall picture. Actually, by far the majority of the occurrences within the AEC are comparable, in kind, to those occurring within any industrial organization.

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Since the establishment of the Atomic Energy Commission (AEC) by the Atomic Energy Act of 1946, the AEC has been responsible for the management of a complex of Governmenbowned nuclear energy facilities. Their design, construction, and operation is by contract with industrial, academic, and nonprofit organizations, rather than directly by Government employees. The operations at these facilities include the production and Processing of special nuclear and radioactive materials, the development of nuclear reactors, the develop ment of nuclear explosives, and research in the physical and biological sciences. The total investment in these facilities is over nine billion A major part of the AEC’s research is conducted at several national laboratories and three weapons development laboratories. Various production facilitiea are operated for the AEC and include nuclear feed materials plants, three uranium gaseous diffusion plants for producing enriched uranium, and two plutonium production complexes. Weapons testing is conducted at the Nevada Test Site. Similarly, various contractors operate test facilitiea at the National Reactor Teating Station in Idaho and at the Nuclear Rocket Development Station in The 1964 revision of the Atomic Energy Act established a comprehensive system of regulatory control over the private use of nuclear and radioactive by-prpduct materials. To implement these responsibilities of operation and regulation, there is a dual organization in which the regulatory activities are separated from promotional and developmental activities. The General Manager, with operational and promotional staffs, administers and directs operations being conducted for the AEC ;the Director of Regulation, with his staff, carries out the regulatory program for licensed activities and assists the General Manager in the technical review of certain reactor proThe AEC has field oflices near its major sites to assist the General Manager in conducting the AEC’s operations. Each office administers contracts within its area of jurisdiction with organizations operating the facilities or otherwise under contract with the AEC. The Director of Regulation has established regional offices in various parts of the United States from which licensee inspections and compliance activities am conducted. Through these contractual and regulatory systems, AEC undertakes to maintain Governmental control and direction in areas of health and safety. The material included herein covers the extory) during the period 1943-70, incorporating both information pertaining to the Manhattan Engineer District, predecessor to the AEC, as well as that of the AEC itself.

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Explanations of Terms Used in This Publication occurrence in a sequence of events which produces death, injury, radiation exposure, or viations listed in appendix A, page 49. cludes AEC and AEC contractor personnel engaged in AEC operations and AEC conresearch, and services contractors. ANSI-American National Standards Institute. uring Work Injury Experience. Standard used by the AEC. BODY BURDEN-The amount of radioactive material present in the body of man or anilates its own repetition. In a fission chain reaction, a fissionable nucleus absorbs a neutron and fissions, releasing more than one additional neutron. These in turn can be absorbed by other fissionable nuclei, releasing more neutrons. A fission chain reaction is self-sustaining when the number of neutrons released in a given time interval equals or exceeds the number of neutrons wanted radioactive particulate matter. sionable materials that will support a selfsustaining chain reaction under stated condiDEATH RATE-The number of deaths per work injury which results in death, permanent total disability, permanent partial disability, or temporary total disability as defined in ANSI 216.1. FIRE LOSS RATIO-Cents loss per $100 of ble of being fissioned by neutrons. abling injuries per 1,000,000 man-hours GLOVEBOX (DRYBOX)-A sealed box in which workers, using gloves attached to and passing through openings in the box, can handle radioactive materials safely. ing one eight-hour day. MAN-HOUR-The equivalent of one man working one hour. NUCLEAR CRITICALITY-The state in which the effective neutron multiplication material equals or exceeds unity. NUCLEAR SAFETY (Bimonthly Technical intendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. PROPERTY DAMAGE RATIO-Cents loss per $100 of AEC property. REM-Roentgen equivalent man. A unit of absorbed dose in biological matter. It is equal to the absorbed dose in rads multiplied by the relative biological effectiveness of the radiation on the part of the body of concern. ROENTGEN-A unit of exposure dose of ion-

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izing radiation. It is that amount of gamma or X-rays required to produce ions carrying one electrostatic unit of electrical charge in one cubic centimeter of dry air under standSEVERITY RATE-The number of days charged per 1,000,000 man-hours worked. Available from Clearinghouse for Federal Scientific and Technical Information, National Bureau of Standards, US. Department of Commerce, Springfield, Va. 22151. (Note: intendent of Documents, U.S. Government Printing mce, Washington, D.C. 20402.) USAEC HEALTH & SAFETY INFORMAUSAEC SERIOUS ACCIDENTS ISSUE Available (if not out of print) from Division of Operational Safety, U.S. Atomic Energy

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The occupational injury and fatality experience, through 28 years of the development of the atomic energy industry under the guidance and direction of the Atomic Energy Commission (AEC) and its predecessor, the Manhattan Engineer District, demonstrates that when management vigorously promotes accident prevention programs, aimed at a specific type of injury, the occurrence of the injury can be The early unknown qualities and effects of nuclear energy provided the incentive to develop the most effective specialized injury prevention program ever devised, with the result that, during 28 years, there were only six deaths attributable to nuclear causes. Three of these occurred at Los Alamos (August 21, 1945, May 21, 1946, December 30, 1958) and were a direct result of exposure to a massive dose of nuclear radiation. The immediate causes of death in the three additional fatalities were the physical effects (i.e., blast, flying missiles, sion of January 3,1961;however, the radiation levels associated with that accident were extremely high and probably would have been fatal. It is also significant that during these ‘On July 24, 1964, the fir& nuclear fatality in a licensed operation occurred an a result of a nuclear criticality accident at a recoverg plant for enriched uranium scrap near Charleston, BI. 28 years there were only 35 workers involved in lost-time radiation nonfatal accidents. These accidents, producing ionizing radiation exposures, were caused by human error, faulty manipulation of controls, deviation from standard operating procedures, faulty mechanical equipment, and other causes such as may be encountered in any other industry. Fatalities from all causes totaled 295 during the 28-year period (see Charts I and 11). Of this number, 181 occurred in construction, 98 in AEC operations (production, research and services), and 16 in Government functions. A list of fatalities occurring in AEC operational activities appear in Appendix A. During this period, there were 17,934 losttime injuries (as defined in ANSI 216.1) attributable to all accidental causes. This gives a 28-year frequency rate (number of injuries per million man-hours) of 2.91. Of the lost-time in AEC operations. This was the experience of posure, which produced over four billion manhours of work and a 28-year frequency rate of 2.12. As indicated above, only 38 of the 9,147 is equivalent to a frequency rate of 0.01. A list of radiation injuries occurring in AEC operations appears in Chart VIII.

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In the AEC's construction activities, there were 7,964 injuries, resulting in a 28-year freqUencY rate of 5-36. This rate compares VeW favorably with the average frequency rate of the National Safety Council (NSC) of 16.8 for ees) frequency rate was 2.38 (853 lost-time injuries). AEC Government experience won vention among Federal employees, in 1957, 1969, 1960, 1962, and 1970. The AEC earned these awards in the small-agency category. ence has always been lower than the all-industry rate reported by 41 industries in the United rate of all industry is 8.6 compared to the 28year AEC frequency rate of 2.9.

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In 1945, and prior thereto, the pressures of war, such as heavy construction work, urgency, and shortages, all combined to produce relatively high accident frequency rates in AEC operations, although they were always below NSC rates. By 1960, the rate for work in operation had dropped t o about 3.0 injuries per million man-hours. From then on, operation frequency rates were low by comparison with other industries. In 1947 through 1949, a renewed heavy construction program produced a construction injury rate of about 10.0. This held the overall frequency rates of the AEC up in those years. A vigorous program concentrating on control of accidents in construction brought the frequency down again, and since 1968, the total frequency for all activities has been 2 2 or less. The proportion of construction work thereafter was small enough to be ineffective, in the overall, even though the construction rate was up in 1969. It is notable that the trend of AEC’s injury frequency (see Chart Iv) in all its operations throughout the years is roughly parallel to the national average, but from a fourth to a third of the national

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As stated regarding the AEC frequency rate, the AEC severity rate was affected adversely by the large amount of construction work during its early years. In 1951, the AEC severity rate and the NSC severity rate were the same. Both have declined over the years; however, that of the AEC shows It is to be noted that a severity rate may fluctuate markedly from year to year, depending upon the fatalities and types of disabilities occurring. Whereas the actual calendar days lost are charged for temporary total injuries, charges are based on 6,000 days for a death or permanent disability, with proportionately fewer days being charged for permanent partial disabilities of varying degrees of seriousness. Thus, fatalities and certain types of injuries can mult in decided peaks in a severity rate. * NUMBER OF DAYS CHARGED PER MILLION MAN-HOURS

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In accordance with its health and safety responsibilities, the AEC must conduct its activities in such a manner as to assure that employee radiation exposures are reduced to the lowest practical levels within established limits. To carry out this responsibility, it has been necessary for the AEC and its contractors to monitor routinely .all employees who might receive a significant radiation dose. AEC and AEC contractor employee exposures for the past 24 years are summarized in Chart VI. This chart shows that during this 24-year period over 99.8% of the employees monitored received an annual dose of less than 5 rem and that over 94.8% received one rem or lese. The majority of exposures in excess of five rem in a year resulted from accidental situations. The more significant (15 rem and over) of these accidental exposures are briefly summarized in Appendix B. During the 28 years of operation of the AEC and its predecessor, radiation rekulted in a very small percentage (0.4) of the total lost-time injuries from all causes as indicated in Chart VII. These specific radiation exposures were classified as lost-time injuries as defined in the American Netional Standards Institute methods for reporting work injuries, ANSI 216.1-1967 (Rev. of 216.1-1954) and AEC Radiation Exposure of AEC and AEC Contractor Personnel to Whole-Body Penetrating Radiation

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Of the 38 workers involved in lost-time radiation accidents, 3 died, 24 showed clinical manifestations attributable to radiation, and 11 were without evidence of radiation effects. Of the second group, 2 received permanent partial disabilities due to radiation, and 3 required removal of a digit because of deposition of plutonium in tissue. but who actually had no evidence of clinical radiation effects were classified as lost-time injuries because they were removed from work and hospitalized for diagnostic tests. Such Gsts were negative in these cases but loss of time was charged according to ANSI standards for Additional information on these injuries concerning date and location of accident and nature and extent of injury are found on Chart VIII. Chart IX provides a comparison of total time lost from injuries due to radiation and to other causes. It is evident from …