Product & Service Directory–2014
101
Research &
Development
Demonstration Project
EPRI is leading a demonstration
project that will instrument a dry cask
system to collect data on the behavior
of high burnup used fuel during loading
and storage.
With no clear path for ultimate
disposition, spent fuel will continue to
be stored in dry storage for an extended
period.Tobetter understand the long-term
storageand transportationbehavior of high
burnup used fuel (>45GWd/MTU), EPRI
is conducting a full-scale demonstration
of an instrumented storage cask loaded
with high burnup fuel. Nuclear plants
have been shifting from lower burnup to
higher burnup fuels in recent years, and
continued research is needed to better
understand the impacts, if any, of storage,
transportation and used fuel management
on high burnup fuels.
The U.S Department of Energy
awarded a contract to EPRI to lead such
a demonstration project, teaming with
Areva Federal Services, Transnuclear,
Dominion Virginia Power, Areva NP,
and Westinghouse. The project will use
an existing TN-32 bolted metal cask
modified with instrumentation to allow
measurements during loadingand storage.
The caskwill be loadedwith three types of
high burnup fuel from Dominion’s North
Anna Power Station.
The specially instrumented lid will
allow temperature measurements to
be taken of the fuel during the thermal
transient and peak assembly temperatures
that will occur during the vacuum-drying
process, and then the lower steady-state
temperatures with the helium backfill
gas during the initial storage period.
Periodic gas samples will be taken during
the first one to two weeks to determine
the amount of fission gas, water vapor,
and hydrogen gas that would indicate
defects of one or more spent nuclear fuel
rods, incomplete removal of water, and
hydrogen generation, respectively. About
two weeks after the drying process, the
cask will be moved to the storage pad
for long-term storage, where periodic
temperature measurements will be taken
throughout the long-termstorage process.
Prior to loading the cask, about two
dozen fuel rods will be removed for
detailed nondestructive and destructive
examination. The pre-characterization
examination will provide essential
information on the physical state of the
high burnup rods and the fuel contained
in the rods prior to the loading, drying,
and long-termdry storageprocess. Similar
tests will be performed at the end of the
long-term storage period to identify any
changes in the properties of the fuel rods
during the dry storage period.
Results from the high burnup
demonstration project will provide
confirmatory data that will help refine
analytical models that can be used to
explore a wider range of conditions
that may occur for various fuel types
and storage conditions. The target date
for loading fuel into the instrumented
cask is mid-2017. EPRI is finalizing a
test plan for the demonstration project,
and activities in 2014 through 2016 will
focus on designing the instrumented lid,
obtaining a license for the modified lid,
identifying the fuel rods to be included in
the test program, procuring the cask, and
conducting a dry run.
Contact: Keith Waldrop, telephone:
Cooling System
Oneof the innovations –apre-cooling
concept using thermosyphon technology
– could produce annual water savings of
as much as 70%, while avoiding seasonal
performance penalties associated with
current dry cooling technologies.
Cooling innovations for nuclear and
other thermoelectric generation plants are
advancing through EPRI’s technology
pipeline toward commercial deployment:
a 1 MW thermosyphon cooler concept
is being demonstrated in association
with Johnson Controls Inc., and a novel
dew-point cooling concept is proceeding
toward pilot testing in association with
the Gas Technology Institute based on
promising results from performance
modeling studies. Additional innovations
are expected to enter EPRI’s pipeline in
2014 based on an ongoing $6 million
solicitation for dry and hybrid dry-wet
cooling technologies cofunded by the
U.S. National Science Foundation (NSF).
The power industry is among the
world’s largest water users in terms of
withdrawal, primarily due to cooling. If
water is not available due to evaporative
loss,resourceconflicts,droughtconditions,
rising water rates, or other factors, power
plant power productioncanbeconstrained,
especially during hot summer hours
when electricity is in peak demand. The
thermosyphon and dew-point cooling
systems could reducewater use at existing
and new power plants, and potentially
expand the number of locations suitable
for siting new thermoelectric capacity.
Thermosyphon cooler technology
applies thermosyphon dry heat rejection
concepts developed for air conditioning
applications to pre-cool the hot water
exiting the steam condenser before it is
introduced to the wet cooling tower. A
1-MW unit, integrating an evaporator
with an air-cooled condenser, recently
completed a full-year test at the Water
Research Center at Georgia Power’s
Plant Bowen. Results demonstrate
that embedding thermosyphon cooling
capacity within existing wet cooling
circuits could produce annual water
savings of as much as 70% compared
to traditional cooling systems, although
power consumption typically rises as
water savings increase. The amount
of water savings is also dependent on
location, amount of equipment installed,
and the control strategy employed. Initial
assessments indicate potentially attractive
economics for deployment at nuclear and
fossil plants facing minor constraints on
water availability.
Dew-point cooling (DPC) technology
is based on a novel cooling tower fill.
Dry channels are positioned between
conventional wet channels, separated
by a thin-walled surface. Evaporative
cooling of the surface’s wet side extracts
heat from ambient air passing over its
dry side. Pre-cooling the incoming air
reduces evaporative losses and allows the
condensate to be cooled close to the dew-
point temperature,well belowthe ambient
wet-bulb temperature—the practical limit
for today’s tower fills.Modeling indicates
that DPC fill retrofits could produce
water savings of up to 20%. In addition,
lower steam-condensing temperatures
would allow operation at lower turbine
backpressure, improving overall power
plant efficiency.
In 2014, the possibility of a field
validation of a 16-MW thermosyphon
cooler module optimized for retrofit
