Fig. 16. No-diversion and diversion UDT charts with alarm charts. Again, the diversion strategy is as described for Fig. 14. The UDT diversion chart shows diversion commencing at about balance number 23, and the average material loss does not begin to decline until after number 63, when diversion has ceased. The alarm chart confirms these observations by the appearance of alarms at about balance numbers (21,23) and the absence of alarms in the vicinity of numbers (63,63). sensitivity can be obtained only by better measurements of the throughput and better control of the correlated errors (such as calibration errors) in the throughput measurements. Figures 17a and 17b show examples of cusum performance surfaces from the simulated materials accounting data used to generate Table VI. Results for Case 1 (the worst case) are shown in Fig. 17a, and results for Case 2 (the best case) are shown in Fig. 17b. The figures illustrate the use of cusum performance surfaces in the design and evaluation of materials accounting systems. The improvement in sensitivity obtained by periodically recalibrating feed and product measuring devices is obvious when the figures are compared. Discussion Until recently, almost no consideration was given to nuclear safeguards accounting requirements during the design. of fuel-cycle facilities, the AGNS plant included. Instead the safeguards system designers were presented with either an existing facility or a relatively complete and fixed plant design. While the results of systems studies might introduce additional measurement instruments or bring about minor changes in operating equipment. they usually did not have any input to the choice of the process to be used in the facility or its mode of operation. Increased recognition of the importance of nuclear safeguards and the need to integrate materials accounting into the process is bringing about a change. Safeguards designers are being consulted early in the design stages of fuel-cycle facilities. The resulting close cooperation between safeguards experts and process and facility designers should identify design alternatives that are both beneficial to safeguards and benevolent to the process. The kind of materials accounting systems discussed above can provide better information on the locations and amounts of nuclear material than is b. a. BIBLIOGRAPHY IAEA Safeguards Technical Manual, Part A, "Safeguards Objectives and Criteria Requirements," International Atomic Energy Agency technical document IAEA-174 (Vienna, 1976). IAEA Safeguards Technical Manual, Part F, "Statistical Concepts and Techniques," International Atomic Energy Agency technical document R. H. Augustson, "Dynamic Materials Control Development and Demonstration Program," Nucl. Mater. Mange. VII(3), 305-318 (1978). H. A. Dayem, D. D. Cobb, R. J. Dietz, E. A. Hakkila, J. P. Shipley, and D. B. Smith, "Dynamic Materials Accounting in the Back End of the E. A. Hakkila, D. D. Cobb, H. A. Dayem, R. J. Dietz, E. A. Kern, E. P. Schelonka, J. P. Shipley, D. B. Smith, R. H. Augustson, and J. W. E. A. Hakkila. J. W. Barnes, T. R. Canada, D. D. Cobb, S. T. Hsue, D. G. Langner, J. L. Parker, J. P. Shipley, D. B. Smith, R. H. Augustson. and J. W. Barnes, "Coordinated Safeguards for Materials Management in a Fuel Reprocessing Plant, Vol. II," Los Alamos Scientific Laboratory report LA-6881 (September 1977). E. A. Hakkila, D. D. Cobb, H. A. Dayem, R. J. Dietz, E. A. Kern, J. T. Markin, J. P. Shipley, J. W. Barnes, and L. A. Scheinman, "Materials Management in an Internationally Safeguarded Fuels Reprocessing Plant, Vol. I," Los Alamos Scientific Laboratory report LA-8042 (April 1980). E. A. Hakkila. D. D. Cobb, H. A. Dayem, R. J. Dietz, E. A. Kern, J. T. Markin, J. P. Shipley, J. W. Barnes, and L. A. Scheinman, "Materials Management in an Internationally Safeguarded Fuels Reprocessing Plant, Vol. II," Los Alamos Scientific Laboratory report LA-8042 (April 1980). E. A. Hakkila. A. L. Baker, D. D. Cobb, H. A. Dayem, R. J. Dietz, J. E. Foley, R. G. Gutmacher, J. T. Markin, H. O. Menlove, C. A. Os- J. L. Jaech. "Statistical Methods in Nuclear Material Control," TID-26298, Technical Information Center, Oak Ridge, Tennessee (1973). G. R. Keepin and W. J. Maraman, "Nondestructive Assay Technology and In-Plant Dynamic Materials Control-DYMAC," in Safeguarding Nuclear Materials, Proc. Symp., Vienna, 1975 (International Atomic Energy Agency, Vienna, 1976), IAEA-SM-201/32, pp. 305-320. T. I. McSweeney, J. W. Johnston, R. A. Schneider, and D. P. Granquist, “Improved Material Accounting for Plutonium Processing Facilities and a 235-U-HTGR Fuel Fabrication Facility," Battelle-Pacific Northwest Laboratories report BNWL-2098 (October 1975). T. D. Reilly and M. L. Evans, “Measurement Reliability for Nuclear Material Assay," Los Alamos Scientific Laboratory report LA-6574 (January 1977). J. P. Shipley. "Decision Analysis and Nuclear Safeguards." in Nuclear Safeguards Analysis-Nondestructive and Analytical Chemical J. P. Shipley. "Efficient Analysis of Materials Accounting Data," Nucl. Mater. Manage. VII(3), 355-366 (1978). Darryl B. Smith earned his bachelor of arts degree in physics-mathematics from Millikin University in 1958 and his Ph.D. in physics from the University of New Mexico in 1968. In 1958, he joined LASL's Physics Division, where he compiled and edited a volume of charged particle cross-section data, investigated tritoninduced nuclear reactions in thin gaseous targets, and used inelastic neutron scattering to study the lattice dynamics of crystal structures. In 1967, he joined the nuclear safeguards research program and has carried out neutron and gamma-ray transport calculations and developed calibration and error-analysis techniques for NDA instrumentation. He is now working on design and evaluation of nuclear materials measurement and accounting systems for nuclear fuel cycle facilities. He has served as an advisor to the IAEA on the qualification and calibration of NDA instrumentation. He is chairman of the Institute of Nuclear Materials Management subcommittee INMM-9, which is responsible for developing ANSI consensus standards on NDA methodology and was chairman, 1974-1975, of the Trinity Section of the American Nuclear Society. James P. Shipley, Group Leader of LASL's Safeguards Systems Group, received his bachelor of science degree in electrical engineering from New Mexico State University in 1966 and his Ph.D. in electrical engineering and computer science from the University of New Mexico in 1973. His background is in electronics, automatic control systems, filtering theory, and applied mathematics for systems analysis. Since joining LASL in 1966, he has been involved in research, development, and design of control systems, including those for solar heating and cooling of buildings. He joined the nuclear safeguards program in 1976, and was instrumental in setting up the Systems Control Group. He contributed Chapter 4. "Decision Analysis for Nuclear Safeguards," to Nuclear Safeguards Analysis: Nondestructive and Analytical Chemical Techniques (American Chemical Society, Washington, DC, 1978) and has served on the editorial board of the Review of Scientific Instruments. Dante Stirpe earned his bachelor of science degree in physics from Union College in New York, his master of science degree at Iowa State University, and his Ph.D. from the University of Missouri. Before coming to Los Alamos in 1962, he worked on electron resonance at General Dynamics/Electronics at Rochester, New York. At LASL, he has done work in shock hydrodynamics and timing and firing devices at the Nevada Test Site, and technology assessments. He is now involved with materials accounting at isotope enrichment facilities. EDITORIAL Don Kerr F on Nuclear Safeguards or nuclear energy to remain an indispensible part of the United States energy supply, three major problems must be overcome both technically and institutionally: assured safety, acceptable waste disposal, and effective safeguards. The Los Alamos Scientific Laboratory is making significant contributions to all three, but improved nuclear safeguards may be the most pressing requirement today. Since the beginning of the atomic era, the thrust of United States nuclear policy has been twofold: to build a strong national defense by developing nuclear weapons and naval propulsion systems and to support the private sector's development of a safe and efficient energy resource. As these efforts have expanded, so have the risks incurred by our accumulation of weapons-usable nuclear materials. The proliferation of nuclear weapons states has become a major national security problem. Similarly, the potential for diversion of nuclear materials from the nuclear fuel cycle by a subnational group has added to the growing arsenal of mass terrorism techniques. Recent guerrilla actions to capture and hold diplomatic hostages in Tehran and Bogota call attention to the need for all major governments, regardless of ideology, to join in common action to protect institutions and communications from the spread of terrorism. In the nuclear age, the threat of terror may be greater than the threat of war between the superpowers. As the world runs short of fossil fuels or the cost to acquire them becomes too high, our reliance on nuclear energy is bound to increase. Among the industrialized countries, France, Japan. West Germany, and the United Kingdom have chosen nuclear energy: Brazil, Argentina, and other developing countries are likely to make the same choice. In the future, unless the tyranny of political terrorists is brought under control, a few may be able to seize, not an embassy, but a nuclear power plant or some other nuclear facility and hold hostage not ambassadors, but entire communities and even nations. Far less difficult actions could produce the same tragic results. The capture of a few kilograms of fissile material and the threat to detonate an improvised nuclear explosive, or the seizure of a few barrels of radioactive wastes and the threat to disperse them in rivers and harbors near large cities could render whole populations defenseless. The challenge to protect nuclear materials from illegal possession is enormous and urgent. It can be met only by a combination of technological and institutional developments. International and national safeguards and security measures to limit the risks of the nuclear era have evolved over several decades. They must continue to evolve. In fact, recent studies (the International Nuclear Fuel Cycle Evaluation and the NonProliferation Alternative System Assessment Program) affirm the need for continuing improvements. |