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Posted Nov 12, 2019, 10:57 PM
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BANNED
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Join Date: Jul 2018
Posts: 4,537
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Quote:
Originally Posted by travis3000
The issue I have with nuclear energy is that in the rare but very likely future scenario of a large solar storm, our electrical grids could be fried. To the point where repair could take years.... these nuclear plants need constant cooling (which requires hydro), and if the grid is fried.... these plants become mini nuclear bombs. Anywhere within 10-20KM becomes incinerated and radioactive. I know nuclear plants have safeguards in place (massive generators, etc), I have always had deep concerns about this energy source. Research back to the Carrington Event in the 1800s, something of that magnitude or greater could spell trouble.
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This has been studied and it appears that modern nuclear plants are safe.
https://www.forbes.com/sites/jamesco.../#2a75b7a170cb
Quote:
Can Nuclear Power Plants Resist Attacks Of Electromagnetic Pulse (EMP)?
Yes. Specifically, the small modular nuclear reactor company, NuScale, out of Oregon, has made their reactor resistant to electromagnetic pulses (EMP) and most other reactor designs should follow.
EMPs are one of those things that many people think is fake, or over-blown, or a conspiracy theorist’s dream. But they are real. EMPs can be either natural, from things like extreme solar geomagnetic disturbances, or man-made like a large thermonuclear detonation or a cyberattack. If they are coordinated with physical attacks then things can get real dicey real fast.
As the U.S. Commission to Assess the Threat to the United States from EMP Attack points out, “the physical and social fabric of the United States is sustained by a system of systems - a complex and dynamic network of interlocking and interdependent infrastructures whose harmonious functioning enables the myriad actions, transactions, and information flow that undergird the orderly conduct of civil society.”
According to the Commission, EMP effects represent arguably the largest-scale common-cause failure events that could affect our electric power grid and undermine our society, leaving it vulnerable on many fronts. High-voltage control cables and large transformers that control the grid are particularly vulnerable. Transformers weigh 400 tons, take two years to build, and cost $7 million apiece. We are already way behind in having backup transformers ready, so if many go out at once, we have a big problem powering our country...
The Nuclear Regulatory Commission tracks this issue closely, and has been examining these issues for more than 30 years, starting in the late 1970s when the agency studied how EMP could affect nuclear power plant safe-shutdown systems. The agency concluded as recently as two years ago that nuclear power plants can safely shut down following an EMP event. NRC drafted a rule last year on maintaining key plant safety functions after a severe event, particularly on how to keep spent fuel pools cool.
On the other hand, Electric Power Research Institute (EPRI) just came out with a 2019 report that says the threats are not as grim as these past studies imply. They found the potential impacts of EMPs on transmission substations do not include long-lasting blackouts, national grid failure and mass casualties, as previously reported. Instead they would lead to regional service interruptions.
"We did not see the dire consequences that some of the other reports have documented," said Randy Horton, senior program manager at EPRI.
EPRI did advise using options such as shielded cables and low-voltage surge suppression devices or filters, diverting the extra surge to the ground.
Regardless of source or level of risk, protection of electric power plants, and upgrading our infrastructure, will be essential in preventing long term outages and in restarting portions of the grid that have failed in the face of wide-area threats...
Nuclear power plants have a special place in any strategy because of perceived threats of meltdowns of the core and of nuclear fuel pools, as well as from public concern over all things nuclear. But in addition, nuclear plants could be the most likely power generators to restart quickest after a pulse and would be the baseload power that could keep critical parts of society operating.
At present, the Nuclear Regulatory Commission has no regulatory framework to address the EMP risk to nuclear power stations, although NRC is currently working to create new fuel storage standards and most nuclear plants are EMP-hardening their back-up generators.
So while there are differing opinions as to the direct threat of an EMP to a nuclear power plant, it is generally agreed that the threat should not be ignored.
So NuScale didn’t ignore it, and set about to actively deter EMP effects in the design of their new small modular nuclear reactor (SMR). NuScale’s SMR is already the most resilient, reliable and flexible of any energy source in history, with Black-Start Capability, Island Mode and First Responder Power, without needing external grid connections, capable of withstanding earthquakes, category 5 hurricanes and F5 tornados, planes crashing into it, floods, and cyberattacks. Now it has added EMP threats and geomagnetic disturbances.
Fortunately, NuScale is the first SMR company to file a license and design certification application with the U.S. Nuclear Regulatory Commission, and it is the first one to have the NRC complete their Phase 1 review – in record time. So the first unit should roll out in only a few years.
NuScale evaluated support systems of their SMR as either likely vulnerable or inherently resilient to an EMP. The evaluation involved a qualitative vulnerability assessment of above and below ground subsystems, including communications, controls, switches, transformers and machinery within the SMR with special attention to the nuclear plant’s ability to safely shut down and the potential to provide continuous power during and after exposure to an EMP pulse.
Several design features allow the SMR to withstand an EMP attack. There are no safety-related electrical loads, including pumps and electric motor-operated safety valves. Because natural convective core heat removal is used, electrically-operated pumps are not needed to circulate coolant. This means that, if necessary, the reactor can shut down and cool itself for indefinite periods without the need for human intervention, adding water, or external electrical power. So the inherent safety of the reactor is impervious to an EMP and can’t melt-down due to an event.
But just being safe isn’t good enough. It would be great to be able to start up right away or, better yet, keep operating right through the event, so that power is available to mitigate, recover and respond to the worst of attack.
The SMR can go into Island Mode operation, not requiring a connection to the grid to provide electrical power, and allowing for a rapid recovery to full power following the event. The reactor modules can keep safely running and go into stand-by mode
such that they can be rapidly put back into service.
Also, safety-related systems are electrically-isolated from the main plant electrical system, and all sensor cables penetrate the reactor containment vessel at a single location (containment vessel top plate), thereby reducing the EMP pathway.
In addition, the reactor building provides effective electric shielding of EMPs by being several-foot thick concrete walls laced with steel rebar, effectively making it into a Faraday Cage, which is an enclosure or structure that can block an electromagnetic field.
Electrical conducting lines are underground, which significantly attenuates the first burst effects. NuScale uses redundant fiber optic cable for communication links, which are immune to EMP effects.
The NuScale plants feature multiple reactors, multiple turbine generators, an Auxiliary AC Power Source (AAPS), two 2MW backup diesel generators for blackstarting the plant, multiple main power transformers (MPTs) and unit auxiliary transformers (UATs), and redundant backup battery banks. Such redundancy is essential for addressing these complex threats.
The design also provides good grounding practices, lightning protection systems, surge arrestors for connections to the switchyard, delta-wye transformers, and circumferentially-bonded stainless-steel piping.
So new nuclear plants are able to be designed, and old ones upgraded, to withstand EMPs better than most energy systems. Their inherent isolation from the rest of the world is similar to why they can so effectively withstand cyberattacks.
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