NEA-1682 U3-U5-PU9-CRITICALS.

1. NAME OR DESIGNATION OF PROGRAM:  Critical Dimensions of Systems containing U235, Pu239, and U233.

3. DESCRIPTION

Compilation of critical data obtained from experiments performed in a number of laboratories during the period of 1945 through 1985. It supplements the Nuclear Safety Guide [Report. TID-7016 (Rev. 2)(ref.2) in presenting critical data on which recommendations of the Guide are based.
  
This report gives critical data without safety factors, and is no substitute for the Guide or for the related document, The American National Standard for Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors (ref.3). This standard is supported by publications of H. K. Clark that interpret criticality information for Pu, U-233 and U-235 systems (ref.4-6).
  
Information for guiding the safety design of equipment for handling the three common fissile materials appears to a certain extent in the Nuclear Safety Guide, and with greater detail in several handbooks (ref.7). Other publications specify conditions for unique processes with particular fissionable material (ref.8).
  
Experiments of several types which contribute results applicable to nuclear design and to safety problems have been described by Callihan (ref.9). Critical measurements with materials of interest in desired configurations yield information of greatest usefulness and accuracy.
  
In some cases, calculated results are desirable to fill in experimental data or to extend them. Where they appear in the reports, they are identified as calculations because of the uncertainty associated with them.
  
Calculated extensions of experimental data are included to show the nature of trends, not to substitute for results of experiments. They should be used with caution.
  
A fundamental aim of this document is to illustrate relationships among critical data. The compilation and correlation of data for this purpose, from many measurements in a number of laboratories, require a certain amount of normalization or reduction to common terms. Frequently, for example, the effects of variations in geometry or density must be removed to show trends in data.

10. REFERENCES

[1] H. C. Paxton, J. T. Thomas, Dixon Callihan, and E. B. Johnson, "Critical Dimensions of Systems Containing U-235, Pu-239, and U-233," Los Alamos Scientific Laboratory and Oak Ridge National Laboratory report TID-7028 (June 1964).
  
[2] J. T. Thomas, Ed., "Nuclear Safety Guide TID-7016," U. S. Nuclear Regulatory Commission report NUREG/CR-0095 (ORNL/NUREG/CSD-6) (June 1978).
  
[3] "Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors," ANSI/ANS-8.1-1983 (Revision of ANSI/N16.1-1975) (American National Standards Institute, Inc., New York, 1983).
  
[4] H. K. Clark, "Subcritical Limits for Plutonium Systems," Nucl. Sci. Eng. 79, 65-84 (1981).
  
[5] H. K. Clark, "Subcritical Limits for Uranium-235 Systems," Nucl. Sci. Eng. 81, 351-378 (1982).
  
[6] H. K. Clark, "Subcritical Limits for Uranium-233 Systems," Nucl. Sci. Eng. 81, 379-395 (1982).
  
[7] H. K. Clark, "Handbook of Nuclear Safety," Savannah River Laboratory report DP-532 (January 1961). F. Abbey, "Manual of Criticality Data, Parts 1, 2, 3," AHSB(s) Handbook 5, UKAEA Health and Safety Branch (1967). "Guide de Criticite, Parts I, II, III," (in French) CEA-R3114, Commissariat a l'Energie Atomique, Saclay (1967). B. G. Dubovskiy et al., "Critical Parameters of Fissionable Materials Systems and Nuclear Safety (A Handbook)," Russian Translation JPRS:42,322, Clearing House for Federal Scientific and Technical Information (1967). R. D. Carter, G. R. Kiel, and K. R. Ridgway, "Criticality Handbook, Vols. I, II, III," Atlantic Richfield Hanford Co. report ARH-600 (1968).
  
[8] H. F. Henry, A. J. Mallett, C. E. Newlon, and W. A. Pryor, "Criticality Data and Nuclear Safety Guide Applicable to the Oak Ridge Gaseous Diffusion Plant," Union Carbide Nuclear Company, K-25 Plant report K-1019 (5th Rev.) (May 1959). E. D. Clayton, "Nuclear Safety in Chemical and Metallurgical Processing of Plutonium," Hanford Atomic Products report HW-68929 (April 1961).
  
[9] D. Callihan, "Experiments for Criticality Control," in Criticality Control in Chemical and Metallurgical Plant, Karlsruhe Symposium, 1961 (Organisation for Economic Cooperation and Development, European Nuclear Energy Agency, Paris, 1961), pp. 589-614.

Critical Dimensions of Systems containins U235, Pu239, and U233
LA-10860-MS (Los Alamos National Laboratory) Vol. I, II, III (1986 Revision)

15. NAME AND ESTABLISHMENT OF AUTHORS: Los Alamos National Laboratory
Los Alamos, New Mexico USA

Critical Dimensions of Systems Containing U235, Pu239 and U233