Uranium hexaflouride freezer/sublimer process simulator/trainer Page: 2 of 6
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
URANIUM HEXAFLUORIDE FREEZER/S UBLIMER PROCESS SIMULATOR/TRAINER'
Charles L. Carnal, Electrical Engineering Department
Tennessee Technological University
Cookeville, Tennessee 38505
James D. Belcher, Perry A. Tapp, Francis R. Ruppel, and John C. Wells
Instrumentation and Controls Division
Oak Ridge National Laboratory
Oak Ridge, Tennessee 37831
ABSTRACT
This paper describes a software and hardware
simulation of a freezer/sublimer unit used in gaseous
diffusion processing of uranium hexafluoride (UF6).
The objective of the project was to build a plant
simulator that reads control signals and produces plant
signals to mimic the behavior of an actual plant. The
model is based on physical principles and process data.
Advanced Continuous Simulation Language (ACSL)
was used to develop the model. Once the simulation
was validated with actual plant process data, the ACSL
model was translated into Advanced Communication
and Control Oriented Language (ACCOL). A Bristol
Babcock Distributed Process Controller (DPC) Model
3330 was the hardware platform used to host the
ACCOL model and process the real world signals. The
DPC will be used as a surrogate plant to debug control
system hardware/software and to train operators to use
the new distributed control svsieir without disturbing
the process.
INTRODUCTION
The gaseous diffusion process consists of a series
cascade of compressors that circulate gaseous UF6
through separation units to enrich the uranium. The
process can be operated efficiently over a wide range of
production capacities. Because compressor power
consumption is directly proportional to the process
inventory level, large plant power swings can be
accomplished by removing or freezing UF6 out of the
‘Research sponsored by the Enrichment
Operations Division, U. S. Department of Energy,
under contract DE-AC05-840R21400 with Martin
Marietta Energy Systems, Inc.
process (power decrease) or subliming UF6 back into
the process (power increase). The Process Inventory
Control subsystem for removing or adding UF6 is called
the freezer/sublimer (F/S). An entire facility will have
scores of F/S units operating in coordinated control to
provide plant power swings as required. Traditionally,
the gaseous diffusion plant was operated for maximum
integrated output, and the plant contracted for large
amounts of "firm" power. However, because of
curtailed demand and the changeover of the enriched
uranium market to a competitive environment,
production costs are of prime concern. The PICS
upgrade will allow the plant to use more of the less
expensive "nonfi m" power by operating at higher
capacities when this power is available.
The purpose of this project was to provide a
process simulation that could be used to (1) validate
distributed control system software being developed
off-site and (2) facilitate operations training on the
new distributed control system without disturbing the
on-line process. The project described in this paper
was limited to process simulation of a single, typical
F/S unit. Figure 1 depicts the physical features of lhc
F/S system and shews the pertinent variables used in
the F/S math model. Mass, mass derivative (or mass
flow), temperature, pressure, volume, and valve
position variables begin with letters M, DM. T, P. V.
and C respectively. The relationships between these
variables will be developed. First, an overview of the
F/S system operating modes is given below.
OPERATING MODES
When it is desired to reduce plant power
consumption. UF6 gas is removed from the plant circuit
by opening valve CB (high-pressure UF6) and allowing
the gas to flow through the Cw control valve into the
F/S vessel. This operational mode is called freeze. In
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Carnal, Charles L.; Belcher, James D.; Tapp, Perry A.; Ruppel, Francis R. & Wells, John C. Uranium hexaflouride freezer/sublimer process simulator/trainer, article, January 1, 1991; Tennessee. (https://digital.library.unt.edu/ark:/67531/metadc1097617/m1/2/: accessed April 18, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.