scholarly journals Transition Core Planning and Safety Analyses in Support of LEU Fuel Conversion of the University of Missouri Research Reactor (MURR)

2020 ◽  
Author(s):  
J. Stillman ◽  
W. Cowherd ◽  
D. Yoon ◽  
E. Feldman ◽  
K. Kutikkad ◽  
...  
Keyword(s):  
Research Reactor ◽  
Fuel Conversion ◽  
University Of Missouri ◽  
The University

scholarly journals Startup, transition core, and molybdenum-99 production upgrade analyses for low-enriched uranium fuel conversion at the University of Missouri research reactor

2020 ◽  
Author(s):  
◽  
Wilson Cowherd
Keyword(s):  
Low Power ◽  
Research Reactor ◽  
The United States ◽  
Fuel Conversion ◽  
Reactor Physics ◽  
University Of Missouri ◽  
Safety Margins ◽  
Enriched Uranium ◽  
The University ◽  
The Impact

Under the direction of the United States Department of Energy (DOE) National Nuclear Security Administration (NNSA) Office of Material Management and Minimization (M3) Reactor Conversion Program, the University of Missouri Research Reactor (MURR®) plans to convert from highly enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. Low power physics startup test predictions, transition core planning, and analysis for a proposed fission-based molybdenum-99 production upgrade were done in support of LEU fuel conversion. As a first step to LEU fuel conversion, low-power physics tests will be performed to calculate reactor physics parameters. These parameters include flux distributions, coefficients of reactivity, and critical assembly measurements. To facilitate this test, reactor physics calculations were performed using MCNP5 to predict the values of these parameters. Implications of these predictions and areas of uncertainty in the prediction analysis are also discussed. Once MURR completes the testing of the initial LEU core, MURR will enter into a series of transition cycles until steady-state mixed-burnup operation is reached. A Python program was developed that incorporated the constraints of MURR operation while minimizing the time MURR will have to operate atypically during the transition cycles. The impacts of the transition cycles on experiment performance are reported, as well as the number of fuel elements needed. Finally, preliminary analysis on a proposed molybdenum-99 production device at MURR was performed. This analysis shows the impact on the reactor power distribution with implications to predicted safety margins as a part of the larger scope of the experiment analysis.

scholarly journals Transition Core Analysis for HEU to LEU Fuel Conversion at the University of Missouri Research Reactor

2020 ◽  
pp. 1-15
Author(s):  
Wilson Cowherd ◽  
John Stillman ◽  
John Gahl ◽  
Leslie Foyto ◽  
Erik Wilson
Keyword(s):  
Research Reactor ◽  
Core Analysis ◽  
Fuel Conversion ◽  
University Of Missouri ◽  
The University

The small-angle neutron scattering spectrometer at the University of Missouri research reactor

1981 ◽  
Vol 14 (6) ◽  
pp. 370-382 ◽  
Author(s):  
D. F. R. Mildner ◽  
R. Berliner ◽  
O. A. Pringle ◽  
J. S. King
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Research Reactor ◽  
Pyrolytic Graphite ◽  
Flight Path ◽  
University Of Missouri ◽  
Beam Incident ◽  
Position Sensitive ◽  
The University

A small-angle neutron scattering (SANS) spectrometer has been constructed at the University of Missouri Research Reactor Facility (MURR). The design of the MURR–SANS is unusual in that the size of the reactor containment building constrains the flight path to be vertical. This is achieved by Bragg scattering upward through 90° from a set of slightly misaligned pyrolytic graphite crystals to provide a neutron beam at 4.75 Å with a wavelength spread of approximately 4.1%. The beam incident on the sample is defined by two matched variable apertures located either 3.0 or 4.5 m apart. The evacuated scattered flight path is designed with removable extensions to match the primary flight path in length. The instrument has an automatic sample handling capability provided by its own dedicated PDP 11/03 computer. The detector is a large assembly of commercially available linear 3He detectors as an economic alternative to a crossed-wire two-dimensional multi-detector. An array of 43 position-sensitive proportional counters, 24 in (609.6 mm) long and 0.5 in (12.7 mm) in diameter, using charge division gives a spatial resolution of 5 x 12.7 mm. The area-averaged detector efficiency is about 84% at a wavelength of 4.75 Å. The range of scattering vectors that can be measured is 0.005 < Q< 0.15 Å−1. The instrument is well suited to a wide variety of experiments on specimens having characteristic dimensions between 20 and 500 Å. MURR–SANS is designed as a user-oriented facility which provides both reasonable resolution and intensity on sample at a modest cost, and forms part of a neutron scattering center.

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