Year
2000
Abstract
This paper demonstrates how an Excel spreadsheet has been used as a production modeling tool to forecast fissile material requirements to meet a production programme. Its wider use has been for future planning purposes not only at the production level but also for strategic planning. The spreadsheet was initially conceived in 1984 for the long-term promulgation of material predictions for Special Nuclear Materials (SNM) and the sensitivities of these materials to a range of factors. These include, but are not exclusive to, material supply, facility availability, process availability, process efficiencies, process ‘bottlenecks’ and to maintain a watching brief on their use in United Kingdom’s Nuclear Weapons and Propulsion Programmes incorporating both production and research activities. Over the period from 1984 to the present day there have been many changes in the management structure relating to these programmes with the current Ministry of Defence management responsibility resting with the Nuclear Weapons Integrated Project Team (NW IPT) and with Nuclear Materials Management at the United Kingdom’s Atomic Weapons Establishment (AWE) under the 2nd GOCO (Government Owned, Contractor Operated) contract recently placed with AWEml, a consortia comprising BNFL, Lockheed-Martin and SERCo. There have been political changes with UK Government statements relating to the production of specified nuclear material in the UK and, following the Strategic Defence Review, statements concerning the reduction of operational warheads held by the UK and consequential reductions in the stockpile of specified fissile materials. At the working level computer technology has moved on apace resulting in rewrites of spreadsheets to meet modern standards, and ever faster computer systems with increasing capability as well as ensuring that software systems used were of proven Y2K compliance. The system is based upon a relatively simple processing route and will incorporate estimated process yields where processes were still in development, and which, subsequently have utilised actual production yields. The production of the spreadsheet has been with two goals in mind, to enable AWE to operate a system with a high degree of confidence to predict accurately production and research requirements and MoD to predict control of material requirements for future decades. Whilst this model has been used for several materials used in the UK Defence nuclear programmes this paper describes its use, in part, for the plutonium production cycle within AWE. The flow sheet described is comprehensive and is representative of the cycle but there are factors that have been omitted for security reasons.