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  • Pat, we have a reactor trip on Unit 5. Containment is isolated. Demon water is isolated. CVCS

  • is isolated. DHR is in service. And pressurizer heater trips has occurred. All safety functions

  • are green. Understand. We've got a reactor trip on Unit 5 and all safety functions are green.

  • That's correct.

  • Ryan, can you take over the plant response to Unit 5?

  • You're in the middle of a simulated reactor trip. Something happened

  • that’s causing an emergency shutdown.

  • Ryan I have acknowledged the alarms. Understand

  • that you've acknowledged the alarms. This demonstration took place at NuScale, a next

  • generation nuclear power company that wants to operate a string of up to 12 small reactors

  • from a single control roomAnd their new model might just revive the nuclear power industry.

  • When you think nuclear, you might imagine a plant like this: enormous cooling

  • towers, generators, steam billowing out the topTheyve been a part of our energy

  • mix for decades all working to harness the power of splitting uranium atomsOr in other

  • wordsNuclear power, to put it simply, is the most complicated way to boil waterWhat

  • youre trying to do is to take the energy that’s produced by splitting uranium nuclei

  • and convert it into steamThat steam then goes to a turbine which turns a shaft which

  • then turns a generator to produce electricity.When the splitting happens, it produces radioactive

  • materials. Much of the nuclear plant is really focused on trying to make sure that these

  • radioactive materials never escape out into the biosphere.

  • There are hundreds of reactors

  • boiling water across the globe, and you might actually be living near oneBut the nuclear

  • industry today is experiencing some major shiftsThe 3 Mile Island and Fukushima disasters

  • prompted countries like Germany and Switzerland to dismantle their nuclear power infrastructure.

  • Despite efforts from Russia and China to kick-start new projects, global construction is currently

  • on a down-swingHere in the U.S., aging reactors are retiring, and Westinghouse, one

  • of the biggest names in nuclear, recently filed for bankruptcy.

  • The argument the nuclear

  • industry used to make is that even though nuclear power plants are expensive to build

  • they are cheap to operate and therefore profitable. That equation has changed in the last seven

  • or eight years. There have been a combination of two things that have been happeningOne

  • is that as these plantsage, the cost of keeping them operational has been increasing

  • because simultaneously and more importantly, the cost of alternative sources of energy

  • has declined dramaticallyThe second thing I would say is that, the argument used to

  • be, oh, weve learned a lot from mistakes in the past. We will be able to lower the

  • cost and how fast these reactors are built, and that has not happened. The South Carolina

  • project was so expensive, the company pulled out of it after spending about $9 billion,

  • that's essentially been abandoned.

  • The Georgia plant is now running at around $25 to $27 billion, compared to

  • a few billion dollars that was the initial expectation. I think the result of that is

  • nobody in their right mind should be thinking about building another large nuclear plant in the country.

  • It’s a tough situation, especially with reports of rising CO2 emissions

  • and calls for alternatives to meet climate goalsAnd that’s where these next generation

  • reactors enter the conversation for multiple countries.

  • Hoping to solve the problems of cost and scale, this new nuclear fleet are called SMRs or

  • Small Modular ReactorsSmall in this context just means it’s producing less

  • than 300 megawatts of electricity. The plants that were being built in South Carolina, the

  • ones being built in Georgia generate about 1,100 megawatts of electricityModular means

  • that you can make these things in a factory. You're manufacturing all your high quality

  • components in parallel you're doing all your civil construction on site. Youre making

  • the pool, youre building the building. And then when the buildings are done, you transport

  • the modules to the site and you install them. Beyond these two there’s really nothing

  • that constrains you about the design of the reactorThere are literally dozens and dozens

  • of SMR designsPortable nuclear power has a back to the future feel to it. Pursued since

  • the Cold War, several designs have found their way inside nuclear submarines and university labs.

  • After decades of attempts,

  • SMRs haven't been the mainstream source of power for local communities just yet,

  • but that might change with NuScale.

  • This all started with a project that was funded by the Department of Energy

  • back in 2000. We were working with the Idaho National Laboratory at the time and we came

  • up with this concept for something small that could be built in a factory. So inside our

  • modules, we start off with the containment vessel. It's about 76 feet long and 15 feet

  • in diameter, it’s big cylinderInside that containment vessel the reactor vessel

  • houses the fuel, the steam generator. It's a helical coil steam generatorEverything

  • you need for power to produce steam is inside that one little vessel. Now the containment

  • and the reactor vessel sit underwater below ground. And you can add on, two, three up

  • to 12 modules in a single pool. So it's scalable because you don't have to add them all at

  • once, you can do them in incrementsEach module will produce about 60 megawatts electric.

  • If you think about homes, it's somewhere around fifty thousand homes would be powered by one

  • moduleThere aren't any additional cooling pumps or generators that could fail in an

  • emergency, a lesson learned from previous disastersBecause a key element NuScale

  • really emphasized with us, is safetyPassive safety really describes the ability to perform

  • a safety function without powerFor our design, the reactors will safely shut themselves

  • down without any operator action or computer action, without any AC or DC power, and they'll

  • remain cooled for an indefinite period of time, without the need to add waterWhen

  • you lose power, the control rods actually fall into the reactor vessel into the core

  • and they're held up normally by electromagnets. So you lose power, they disengage and they

  • fall. So you go from two hundred megawatts thermal to about 10 or 11 megawatts in a second

  • or so. If you look at the control room here, you'll see that a lot of things that we do

  • really don't require operator action at all. All the procedures come up on the screens

  • themselves and they help you execute the procedures, and theyll help correct you if you make

  • a mistake it's a smart control roomWhich all seems quite miraculousto have a nuclear

  • control room run mostly on its ownNuScale’s timeline has more tick marks ahead. Their

  • plant operations are still just on paper or at prototype stageTheyre aiming to turn

  • on their first commercial plant near the Idaho National Laboratory by 2026, which brings

  • the project full circleWe finished our design certification applicationIt's a

  • pretty comprehensive checklist, so application alone was 12,000 pages. We're on track to

  • get this design certified with the final safety evaluation report coming out in September

  • of 2020. So, that’s the target. And within their application, NuScale is asking the U.S.

  • Nuclear Regulatory Commission for a different kind of zoning boundaryIn the United States,

  • there's a requirement that you have an emergency planning zone around your plant and that zone

  • is a 10 mile radius. The reason we can request a smaller emergency planning zone is because

  • of the very high level of safety that we offer. If we go back to their animation, the reactor’s

  • sitting in a pool that’s below ground with a biological shield on top of that and in

  • a seismic category which is earthquake proof, hurricane proof type building.

  • In our analysis, we show that we don't exceed regulatory doses under

  • the worst case accident conditions at the site boundary so that changes the game significantly in

  • that we can be in closer proximity to population centers. If you have an SMR and it has an

  • accident, it would have less amount of radioactive material to disperse it would have less energy

  • to disperse. These are laws of physics in certain complicated circumstances that are

  • hard to predict in advance. If you think about the kind of accidents weve seen in the

  • past it is almost always been a bunch of circumstances which nobody had envisionedIf youre

  • thinking about the community and you go and say, “Look, we want to build this nuclear

  • plant near you but there is a small chance that something might go wrong it’s quite

  • possible you might have to leave your house and never come back because it’s going to

  • be contaminated with radioactivity. How do you feel about it?” Quite a few people would

  • say, “No, I don’t think I would want thatDespite this risk potential, the hundreds of reactors

  • operating worldwide have had a pretty safe track record, and overall have caused less

  • loss of life than coal or natural gasThe design & safety of future reactors in the

  • US are assessed by the Nuclear Regulatory CommissionBut there’s some context to

  • this agency that bears keeping in mindThe NRC’s fortunes, in a sense, depend on the

  • industry that it is regulating. If the nuclear industry were to essentially shrink and vanish,

  • the NRC would essentially have to vanish too. The NRC and NuScale have been talking to each

  • other for years now and trying to say, “Okay, here's our rules. Here's how you interpret

  • these rules. Here's how we can modify our design. All of which does not seem to me to

  • be a thoroughly independent process. There’s been a reported history of regulatory capture

  • in the nuclear industry, but it shouldn’t come as any surprise. What entity other

  • than a state government can take on the capital and risk associated with investing in nuclear?

  • Government funding does play an important part. The question, of course, to ask is whether

  • the government should be spending its money on this pursuit. Of course, that’s a different

  • question. The new nuclear power movement is appealing to governments who see the potentialOne

  • module could produce 60 million gallons of clean desalinated water per day. So a 12 pack

  • would be enough to provide all the water needs for a city the size of Cape Town South Africa.

  • On the flip side, SMRs could exacerbate pre-existing geopolitical tensions.

  • China has said they are also developing SMRs. The first place that they want to deploy are on

  • these deserted islands, in the South China Sea that are in disputesIf youre concerned

  • about proliferation, then SMRs are not small in any meaningful sense. With these forces

  • ahead, eyes will be on NuScale as  they work to reshape the industry and roll out what

  • they are betting on to be a smart, scalable model of nuclear power.

  • Their hope is that a safer designan automated control roomand other key features will overcome the hurdles

  • that caused previous ventures to failHowever, there are still open questions over nuclear

  • waste, protecting against proliferation, and how a truly passive nuclear plant operates

  • in real time. But until this

  • model is put to the test, the ultimate question for nuclear - of whether smaller really is

  • better - remains an open one.

Pat, we have a reactor trip on Unit 5. Containment is isolated. Demon water is isolated. CVCS

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微型核反應堆即將到來,它們可能會重塑能源產業。 (Mini-Nuclear Reactors Are Coming, and They Could Reinvent the Energy Industry)

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    林宜悉 發佈於 2021 年 01 月 14 日
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