Earthquake
Simulation
By Alex Broyles, Entergy Nuclear.
Alex Broyles
Alex Broyles started his career as
a contractor for NASA/JSC/Texas
Engineering Experiment Station
where he helped
design mechanical
components for a
radiation dosimeter
which is now
installed on the
International Space
Station. After
briefly working for
Westinghouse at
Comanche Peak
Nuclear Power Plant,
Broyles worked
in engineering at
Vermont Yankee
from May 2011 to
April 2013. He
transferred to the Indian Point simulator
engineering group in April 2013. He
is currently pursuing a Professional
Engineering license in New York.
Broyles received a degree in Nuclear
Engineering from Texas A&M University
in 2011.
Nuclear Energy Institute’s Top Industry
Practice (TIP) Awards highlight the
nuclear industry’s most innovative
techniques and ideas.
This innovation won the 2015 Training
Award.
The team members who participated
included: Alex M. Broyles, Sr. Simulator
Specialist; Dave Axelby, Sr. Simulator
Specialist; Jerry Gullick, Sr. Simulator
Specialist; George Liebler, Sr. Simulator
Specialist; Dennis Celentano, Sr.
Instructor, Entergy Nuclear.
Summary
The March 2011 T
ō
hoku earthquake
and associated Fukushima Daiichi nucle-
ar disaster prompted interest in creating a
realistic earthquake simulation model at
the Indian Point (IPEC) simulators. The
scope of the requested model included
dynamic effects of “tank sloshing” on
control room indicators and physical vi-
brations. There was previously no model
in either simulator for determining the
effects that seismic activity would have
on indicated tank levels, and no method
to simulate earthquake vibrations. Us-
ing seismic calculations from a Updated
Final Safety Analysis Report (UFSAR)
referenced document TID-7024, “Nuclear
Reactors and Earth-
quakes”, the IPEC
simulator group was
able to create a generic
earthquake
software
model to mathemati-
cally simulate dynamic
effects of seismic mo-
tion on liquid storage
tanks. This model ac-
counts for tank orien-
tation, tank size, tank
inventory, and tank
shape. The control
room indication af-
fected by tank slosh-
ing includes level
meters, annunciators, and set point actua-
tions. The mathematical model is writ-
ten in the Fortran programming language,
and can be modified to function in most
control room simulators with few modifi-
cations. Several other facilities have since
reached out to the IPEC simulator group
for assistance in developing an identical
model at their simulators. Furthermore,
the IPEC simulator group installed sev-
eral high-power subwoofers underneath
the simulator floor to create physical vi-
brations during the earthquake scenario.
Low-frequency earthquake sound plays
during earthquake malfunction, which
creates powerful vibrations with very
little audible noise other than the noise
created by panel, floor, and light fixture
vibrations. The finished project enhances
scenario realism and operator training by
accurately simulating the dynamic effects
of seismic vibration on control room in-
dications of plant instrumentation, and
creates the sensation of earthquake mo-
tion. Additionally, the scenarios used in
the INPO Comprehensive Performance
Evaluations (CPE) for both IPEC Unit 2
and Unit 3 featured seismic scenarios en-
hanced with the upgraded seismic mod-
els. During the CPE simulator scenarios,
the INPO evaluating team and Licensed
Operators were impressed by the earth-
quake realism.
Safety
The
advanced
modeling
of
earthquake seismic effects enhances
operator and emergency planning training
to focus on nuclear safety events that were
previously not simulated. There was
previously no training on the expected
effects of seismic activity on control
room instrumentation, or the magnitude
of tank level oscillations during a seismic
event. Demonstration of the real-
time effects of seismic motion was not
previously available to nuclear control
room simulators. The events following
Seismic Oscillations.
52
NuclearPlantJournal.com Nuclear Plant Journal, July-August 2015
CST = Condensate Storage Tank, RWST = Refueling Water Storage Tank,
SG-31 = Unit 3 Steam Generator #1
