LIMITS OF ERROR MODEL FOR A PuO2+ UO2 FUEL FABRICATION INVENTORY

Year
1970
Author(s)
Robert H. King - Westinghouse Electric Corporation
Bartley W. Conroy - Westinghouse Electric Corporation
H. Donald Moss - Westinghouse Electric Corporation
Abstract
Recent Atomic Energy Commission regulations combined with sound business practices required us to examine the \"limits of error\" associated with the material balance of special nuclear materials after a physical inventory. To this end our first formal attempt to define these limits is presented in this paper with the hope that through mutual assistance, interest and need, new and better techniques will be developed to satisfy the demands of national security and the economics of business. To put this paper in the proper perspective, we must keep in mind that the technique described is an interim one which met our needs when this inventory was conducted. Also, no attempt was made by us to apply this technique to an operation involving diverse nuclear fuel materials. Data are being presented for one inventory involving a single account. However, application of this method to each contract (or account) and the subsequent combining of limits of error will yield a confidence interval for the total material held under our license. In April 1969, the Westinghouse Plutonium Fuels Development Laboratory (PFDL) received the first of four shipments of plutonium nitrate solution which is being used to demonstrate a working process for the preparation of fuel rods containing mixed uranium-plutonium oxide fuel. Under the Plutonium Recycle Program, co-sponsored by the Edison Electric Institute and Westinghouse, 720 plutonium-enriched 10-foot fuel rods with Zircaloy-4 cladding will be fabricated and installed in assemblies. These assemblies will be shipped to the San Onofre site and loaded into the pressurized water reactor as part of the scheduled refueling in 1970. Approximately 50 kilograms of plutonium will be combined with 1,700 kilograms of normal uranium to produce 3 w/o percent plutonium in mixed uranium-plutonium dioxide.