Independent fission product yields are primary input nuclear
data in the evaluation of nuclear reactor after-heat when using a
nuclide-decay summation method. The error in yield values is one
of the major causes of uncertainty of this calculation. Since only
a small fraction of the fission product yields has been...
Unit cell or pin cell calculations form the basis for
most nuclear core modeling. Because of this, it is of primary
importance to perform these unit cell calculations
accurately.
The subject of this thesis is the analysis of one of
the major approximations made in unit cell modeling, the
infinite...
A recent review of nuclear reactor emergency core
cooling systems has required renewed investigations into
the present knowledge of experiments which have measured
after-heat. Of special interest are some experiments which
were performed after Shure's 1961 evaluation, upon which
the American Nuclear Society (ANS) recommended after-heat
curves are based.
Experiments...
The magnitude of the effect on decay heat of neutron
capture by fission products for hypothesized "worst case"
irradiations was examined. This effect is shown to be
small (less than 2 percent) for times less than 1,000
seconds and a simple model is presented for estimating
the magnitude of the...
The experimental measurements of the decay heat from
the products of the thermal fission of U-235 have been compared
with the OSU-proposed decay heat standard. These experiments
are intended to verify the decay heat calculational
methods and nuclear data files. The comparisons have
included the previous experiments reviewed by Perry...
The uncertainty in decay energy for those fission products
which contribute significantly to reactor shutdown
power was evaluated. The methodology used assigned significantly
larger uncertainties for data which were theoretically
predicted than it did for experimentally determined
data. The uncertainty was modeled as an increasing function
of distance from beta...
A method of calculating decay heat is presented which is a simplification of existing calculational methods, the summation method in particular. The method involves the assumption that one physical process, neutron capture, is negligible in order to simplify the governing physical equations. A Greens function is derived and the decay...
There are two primary methods of determining the decay
heat generated after the shutdown of a nuclear reactor. One
of these methods is integral experimental measurement of
decay heat from the products of thermal-neutron fission of
235
U. The other method is a summation calculation (computer
codes) based on nuclear...