[Three Minute Thesis 2018, Alok A. Deshpande - Building Safer Nuclear Power Plants. Department of Civil, Structural, and Environmental Engineering.]
[Speaker: Kevin O'Neill] I will ask Alok to join me on stage.
He is of Indian descent. His department is civil, structural and environmental engineering.
Among his passions, in his future he hopes, is research in earthquake engineering.
Presentation title is: Building Safer Nuclear Power Plants.
We welcome you Alok Deshpande.
Excuse me - Deshpande - is that the best pronunciation Alok? Thank you very much.
Again: building safer nuclear power plants. Ready, set and pitch!
[Speaker: Alok Deshpande] Imagine an earthquake striking a nuclear power plant.
How safe do we want that structure to be?
Probably much safer than any other structure, because as we have seen at
Chernobyl and Fukushima, the impacts of a failure in a nuclear facility can be
felt for generations. Nuclear power plants, like other thermal power plants,
generate a lot of heat and this heat is carried to the power turbines using
steam pipes. Earthquake shaking has the potential to rupture these steam pipes.
If this were to happen, then the high pressure, high temperature steam
contained within would, spew within the airtight containment structure. Think of
a pressure cooker. How would this affect its structural safety? Also remember that
earthquakes are usually followed by aftershocks which can be just as intense
as the main shaking. As part of my doctoral research in structural
engineering, I am studying the effects of these elevated temperatures on the
behavior of the structure, specifically on its strength and stiffness, and its
ability to resist future aftershocks. Since it's not practical to test the
structure though, we structural engineers usually build and test its components in
the lab. Nuclear power plants are built almost entirely of concrete walls. So I
built concrete wall specimens and subjected them to a wide variety of
combined thermal and structural conditions, just as expected in a thermal
accident. I saw in these tests that there was a significant reduction in stiffness.
But the good news is that there was no reduction in strength, even at
temperatures 50 percent higher than those expected in such accidents.
I'm using these observations now, to write recommendations that can be used
by designers to assess safety of existing plants after such an accident,
and also design safer, newer plants. Since the behavior of the structure is
defined by the behavior of its materials, I am also studying the behavior of
concrete itself, when subjected to high temperatures. This will allow me to
better understand the behavior of the concrete walls that I tested.
Through the course of this study and by understanding the mechanisms of damage
in concrete, I have developed a new steel and polymer fiber reinforced concrete material.
This material performs significantly better than conventional concrete,
both at normal, as well as high temperatures. Such a robust material has
applications in other structures too. Structures like buildings, bridges and
tunnels, which can otherwise see catastrophic damage due to fire events.
In summary, it's vital to ensure the safety of nuclear power plants.
And understanding the effects of elevated temperatures, both on concrete and
concrete structures, including the development of newer, more robust
materials, are important steps in this direction. And so we can all have a safer
nuclear future. Thank You.
[Audience applauds.]
[Speaker: Kevin O'Neill] Thank you Alok. I did a live shot for Channel 2 at the shake table,
right - isn't that the shake table what it's called here? Right? The- the earthquake
testing facility right? And I actually did a live shot, I believe, at a facility
that used that table - Taylor Devices, in North Tonawanda. They've have used your -
your facility and yeah - and again similarly with my live shots then
not that anybody cares but [audience laughs] he discu- I said so what are we- what are we- what is this
big giant ten-foot thing here? Well this is a- a damper, a viscous damper used to
absorb the potentially destructive energy that an earthquake, or any sort of
seismic- hold on, so it's the shock absorber for a building? Yes.
OK, that's what I'm gonna say it is. [Audience laughs.] It's a shock absorber for a building. It's just
a 10-foot version, instead of the little ones you put in your car.
[Closing slide, UB Graduate School logo, facebook.com/UBGradSchool. @UBGradSchool, Blackstone LaunchPad logo, buffalo.edu/entrepreneurship.]