Code requirements document: MODFLOW 2. 1: A program for predicting moderator flow patterns

Technical Report · Sun Mar 01 00:00:00 EST 1992

DOI:https://doi.org/10.2172/7368609· OSTI ID:7368609

Peterson, P F ^[1]; Paik, I K ^[2]

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1. Univ. of California, Berkeley (United States). Dept. of Nuclear Engineering
2. Westinghouse Savannah River Co., Aiken, SC (United States)

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in operation of the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides transient moderator flow pattern information with stratification effects, and tracks the location of ink plumes in the reactor. The code, written in Fortran, is compiled for Macintosh II computers, and includes subroutines for interactive control and graphical output. Removing the graphics capabilities, the code can also be compiled on other computers. With graphics, in addition to the capability to perform safety related computations, MODFLOW also provides an easy tool for becoming familiar with flow distributions in SRS reactors.

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC09-89SR18035
• OSTI ID: 7368609
• Report Number(s): WSRC-TR-92-140; ON: DE93017276
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
C REACTOR
HYDRAULICS
K REACTOR
L REACTOR
P REACTOR
R REACTOR
APPLE COMPUTERS
COMPUTER GRAPHICS
COMPUTER PROGRAM DOCUMENTATION
DIFFUSION
ENGINEERED SAFETY SYSTEMS
FLUID FLOW
FORTRAN
HYDRODYNAMICS
M CODES
MANUALS
MODERATORS
OPERATION
PERFORMANCE
PLUMES
REACTOR SAFETY
SAVANNAH RIVER PLANT
SPATIAL DISTRIBUTION
STRATIFICATION
TEMPERATURE DISTRIBUTION
COMPUTER CODES
COMPUTERS
DISTRIBUTION
DOCUMENT TYPES
ELECTRONIC CIRCUITS
FLUID MECHANICS
HEAVY WATER MODERATED REACTORS
MECHANICS
MICROELECTRONIC CIRCUITS
MICROPROCESSORS
NATIONAL ORGANIZATIONS
PRODUCTION REACTORS
PROGRAMMING LANGUAGES
REACTORS
SAFETY
SPECIAL PRODUCTION REACTORS
US AEC
US DOE
US ERDA
US ORGANIZATIONS
220900* - Nuclear Reactor Technology- Reactor Safety
220600 - Nuclear Reactor Technology- Research
Test & Experimental Reactors
990200 - Mathematics & Computers