Nuclear Plant Journal, July-August 2015 NuclearPlantJournal.com
53
the March 2011 T
ō
hoku earthquake and
associated Fukushima Daiichi nuclear
disaster clearly show a need for advanced
seismic training. Operator response and
preparation for an earthquake event has
been enhanced as crews have been able
to observe, diagnose, and experience
the symptoms in a real-time simulator
environment, rather than by discussion in
a classroom environment.
Innovation Response
The Fukushima Daiichi nuclear
disaster prompted interest in enhancing
seismic training. The IPEC earthquake
simulator uses innovative techniques for
simulating seismic activity in the control
room simulator. The software model
uses unique programming techniques for
solving the mathematical relationship
between tank dimensions, inventory,
center of mass, and forces applied to the
tank and the fluids in order to find the
maximum displacement of water for the
system. The tank properties are saved
into an external data file in order to allow
rapid changing, adding, or removing
of additional tanks in the model. After
the maximum displacement of water in
the system is solved, a normalized time-
based acceleration spectrum is applied
to the maximum displacement in order
to simulate motion. This spectrum is
based on the normalized acceleration
spectra of 4 powerful Californian
earthquakes with average magnitudes of
6.5, recorded 30-100 miles from slipped
fault center. Once the acceleration
spectrum is applied, the displaced water
volume is added to the original tank. The
simulator annunciators, level indicators,
and bistables react to this change in level
of tank, which causes oscillations in tank
level indicators and alarming/clearing of
annunciators. This behavior is in line
Normalized_Acceleration_Spectrum.
NuScale Power has attained the
Triple Crown for Nuclear Plant
Safety™. With NO operator action,
NO AC or DC power, and NO
added water, the NuScale Power
Module™ will achieve safe,
self-cooled shutdown, and maintain
it indefinitely. Using natural
forces—convection, conduction,
and gravity—the NuScale Power
Module eliminates many of the
complex mechanical systems found
in conventional nuclear power
plants and other small modular
reactor designs.
Safety: The Element of Nu.™
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3
with what was described at North Anna
Nuclear Generating Station after the
2011 Virginia Earthquake. This seismic
modelling approach is unique and has
not been used before for nuclear control
room simulators. In order to simulate
vibrations and motion in the simulator,
high-powered subwoofers were placed
underneath the floors. During the
earthquake transient, low frequency noise
is played through the subwoofers for the
duration of the simulated earthquake.
Most of the audible noise from this
technique is a result of vibrating panels,
light fixtures, and floor tiles. The sound
system is an innovative method of
producing powerful vibrations which
accurately represent seismic activity.
Transferability
Response
The IPEC earthquake simulation
models have been used outside of
training to aid in interfacing with
the public. The earthquake model is
routinely demonstrated during plant
tours of the control room simulators in
order to demonstrate the thoroughness of
operator training. Additionally, the IPEC
earthquake model has been presented at
the industry conference SimTech in 2014.
The mathematical model is written in the
Fortran programming language, and can
be modified to function in most control
room simulators with few modifications.
Several other facilities have since
reached out to the IPEC simulator group
for assistance, source code, flow charts,
equations, and graphics for developing an
identical model at their simulators.
Contact: Alex Broyles, Entergy
Nuclear, telephone: (914) 254-2625,
email:
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