Uncollided Flux Techniques for Discrete-Ordinate Radiation Transport Solutions in Rattlesnake

Technical Report · Mon Aug 01 04:00:00 EDT 2016

DOI:https://doi.org/10.2172/1364492· OSTI ID:1364492

Ragusa, Jean C. ^[1]; DeHart, Mark D. ^[2]

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1. Texas A & M Univ., College Station, TX (United States)
2. Idaho National Lab. (INL), Idaho Falls, ID (United States)

One of the only real-time-resolved measurement tools used at the Transient Test Reactor (TREAT) is the fast-neutron hodoscope. The hodoscope was used for monitoring and measuring fuel motion during a transient pulse. The hodoscope is a line of sight detection and imaging system that provides both temporal and spatial resolution of fuel motion during transients, and in-place measurement of fuel distribution during and after transient experiments. However, the hodoscope relies on fast neutron streaming out of the reactor core, which provides a challenge to transient modeling and simulation. However, use of a first collision source approach can be used to overcome this shortcoming. Hence, the TREAT modeling and simulation team has initiated research to implement such capabilities in the neutron transport code Rattlesnake. This report reviews uncollided flux techniques (first and last collision methods) to be implemented in the Rattlesnake SN code in order to mitigate ray effects in modeling the TREAT reactor+hodoscope system. Angular discretization techniques (SN and PN) for the transport equation are notoriously poor at capturing effectively streaming effects.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 1364492
• Report Number(s): INL/EXT--16-39796
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
DISCRETE ORDINATE METHOD
FAST NEUTRONS
HODOSCOPES
NEUTRON TRANSPORT
TEST REACTORS
TREAT
first collision
last collision
streaming
transport
uncollided