Imágenes de páginas
PDF
EPUB

47.222.09

Preface The Advisory Committee on X-ray and Radium Protection was formed in 1928 under the sponsorship of the National Bureau of Standards and with the cooperation of the leading radiological organizations upon the recommendation of the International Commission for Radiological Protection. The Committee, small in size, functioned effectively until the advent of atomic energy which introduced a large number of new and serious problems in the field of radiation protection.

At a meeting of this Committee in December 1946, the representatives of the various participating organizations agreed that the problems in radiation protection had become so manifold that the Committee should enlarge its scope and membership and should appropriately change its title to be more inclusive. Accordingly, at that time the name of the Committee was changed to the National Committee on Radiation Protection. At the same time the number of participating organizations was increased and the total membership considerably enlarged. In order to distribute the work load, eight working subcommittees were established as noted below. Each of these committees is charged with the responsibility of preparing protection recommendations in its particular field. The reports of the subcommittees are approved by the main committee before promulgation.

The following parent organizations and individuals comprise the main committee: H. L. ANDREWS, United States Public Health Service. E. G. WILLIAMS, M. D., United States Public Health Service. SHIELDS WARREN, M. D., United States Atomic Energy Commission. K. Z. MORGAN, United States Atomic Energy Commission. L. F. CURTISS, National Bureau of Standards. L. S. TAYLOR, National Bureau of Standards. E. E. CHARLTON, National Electrical Manufacturers Association. L. L. CALL, National Electrical Manufacturers Association. H. B. WILLIAMS, M. D., American Medical Association. R. S. STONE, M. D., Radiological Society of North America. G. FAILLA, Radiological Society of North America. R. R. NEWELL, M. D., American Roentgen Ray Society. J. L. WEATHERWAX, American Roentgen Ray Society. E. QUIMBY, American Radium Society. J. E. WIRTH, American Radium Society. L. S. TAYLOR, International Commission for Radiological Protection. R. C. PEAVEY, Secretary, National Bureau of Standards.

The following are the subcommittees : Subcommittee 1. Permissible dose from external sources, G. Failla,

chairman. Subcommittee 2. Permissible internal dose, K. Z. Morgan, chairman.

Subcommittee 3. X-rays up to two million volts, H. O. Wyckoff,

chairman. Subcommittee 4. Heavy particles (neutrons, protons, and heavier),

Dean Cowie, chairman. Subcommittee 5. Electrons, gamma rays, and X-rays above two million

volts, L. Marinelli, chairman. Subcommittee 6. Handling of radioactive isotopes and fission products,

H. M. Parker, chairman. Subcommittee 7. Monitoring methods and instruments, H. L. Andrews,

chairman. Subcommittee 8. Waste disposal and decontamination.

With the increasing use of radioactive isotopes by industry, the medical profession, and research laboratories, it is essential that certain minimal precautions be taken to protect the users and the public. The recommendations contained in this handbook represent what is believed to be the best available opinions on the subject as of this date. As our experience with radioisotopes broadens, we will undoubtedly be able to improve and strengthen the recommendations for their safe handling and utilization.

Through the courtesy of the National Research Council about a year ago, several hundred draft copies of this report were circulated to all leading workers and authorities in the field for comment and criticism. The present handbook embodies all pertinent suggestions received from these people. Further comment will be welcomed by the committee.

One of the greatest difficulties encountered in the preparation of this handbook lay in the uncertainty regarding permissible radiation exposure levels—particularly for ingested radioactive materials. The establishment of sound figures for such exposure still remains a problem of high priority for many conditions and radioactive substances. Such figures as are used in this report represent the best available information today. If, in the future, these can be improved upon, appropriate corrections will be issued. The subject will be under continuous study by the two subcommittees mentioned above.

The present Handbook has been prepared by the Subcommittee on the Handling of Radioactive Isotopes and Fission Products. Its membership is as follows:

H. M. PARKER, Chairman. L. MARINELLI.
L. F. CURTISS.

G. FAILLA.
P. C. AEBERSOLD.

J. G. HAMILTON.
J. E. ROSE.

M. M. D. WILLIAMS.
E. U. CONDON, Director.

of indust protection use

SAFE HANDLING OF
RADIOACTIVE ISOTOPES

I. General Considerations

1. Scope of This Handbook Prior to World War II the use of radioisotopes was essentially limited to a few locations having access to cyclotron-induced activities. The addition of pile-induced activities, either as fission products or as special irradiations, has changed the magnitude of the related protection problems. Widespread laboratory and industrial use of radioistopes is foreseen. This involves the protection of scientists and technicians in one case, of industrial employees in the other, and of the public in both cases. This handbook cannot give detailed recommendations, necessary and sufficient for all cases. It is, therefore, planned to give the general recommendations suitable for typical laboratory or small industrial operations. In all cases management specifically assumes the responsibility for the proper selection and maintenance of the standards necessary for safe operation. The small laboratory, handling low levels of radioactivity, may modify or omit some of the following recommendations. A periodic review of such modifications by a competent radiation protection authority may be desirable. The large laboratories and industries will require more detailed control. The employment of full-time personnel qualified in radiation protection is then desirable, and should be mandatory where the staff working regularly with radioactive material exceeds 25.

Specific attention is directed to the usage of "shall” and "should” throughout the recommendations. The former is used in a mandatory sense. The latter applies to those recommendations that may be redundant at low activity levels, optional at intermediate levels, and essential at high levels.

2. Available Radioisotopes Table 1 lists the radioisotopes of generally greatest interest, and indicates the order of magnitude of the amounts normally available. A knowledge of the sites of deposition and elimination routes is a partial requirement for the hazard evaluation and tests for each particular isotope. Severe radiation hazard is associated with those isotopes that have unfavorable combination of long half-life, high uptake, deposition in small organs or in bone, and low elimination rates.

« AnteriorContinuar »