In fuel pin fabrication, there is no assurance that a
fuel pellet will be loaded concentrically. Therefore,
azimuthal variations exist in the temperature field giving
rise to asymmetry in the neutron flux distribution and pin
stresses. Calculations must be made to determine the two
dimensional temperature profile which may then...
Several fuels are being investigated for fast breeder reactor
applications. One promising concept is sphere-pac mixed carbide
fuel. As a part of the development of this fuel concept it is
necessary to determine the behavior of the irradiated fuel for safe
and reliable operation on a sound economic basis. It...
Large digital computer reactor fuel performance codes
perform repeated calculations of temperature profiles
during transients. The thermal response is required to
calculate the mechanical behavior. This mechanical
response in turn feeds back to the thermal calculations
through mechanisms such as fuel swelling or shrinking,
causing changes in the fuel-clad gap...
An important element in rector safety and fuel performance assessments is the efficient calculation of the time dependent temperature profiles within reactor fuel pins. Because the fuel pins have temperature dependent thermal properties, the governing partial differential equations are nonlinear. Traditionally, finite difference or finite element methods have been used...
In this study a method has been demonstrated by which
the departure from nucleate boiling ratio (DNBR) can be
readily determined for nuclear transients through application
of the COBRA-IIIC/MIT computer code. For input,
boundary conditions were specified relating the time-dependent
variations of core inlet coolant temperature,
system pressure, core heat...
The establishment of any thermal model of reactor fuel
requires a thorough understanding of the behavior of the
thermal conductivity. This is especially true in the case
of sphere pac fuels where the conductivity is a function
of many variables beyond those normally affecting conventional
fuels. One of these variables,...
Through a joint effort by the Swiss Federal
Institute for Reactor Research and Oregon State
University, the fuels modeling code SPECKLE is being
developed to model sphere-pac mixed carbide nuclear fuel.
Major parameters, such as fission gas release, fuel
restructuring phenomena, and the temperature and porosity
distributions in the fuel...
Muitiregion annular geometry is a basic feature of energy removal
systems ranging from advanced heat exchangers to fission reactor fuel
rods. For the symmetric cases, the heat conduction through annular regions
is well defined. However, for a shift of an annular region, analysis
of the system must be made in...
The use of advanced concepts can make the nuclear fuel
cycle more efficient by allowing pins to be operated at
high powers and to higher burnups. Among the more
promising concepts in advanced fuels is sphere pac fuel.
In a first attempt to bring together models describing
individual phenomena, the...