Portable Nuclear Substation fits in a truck

[winnie]

If it fits in a shipping container, it's less than eight feet wide. If the round-ish reactor itself fits in an 8x8-foot footprint, there's a 12x8-foot space for the turbine, generator and condenser. (or maybe a 32x8-foot space ... they didn't specify which standard container it fits in.
(that's one of the nice thing about standards ... there are so many different ones to choose from)

I bet that they will just barely fit in a 53 foot long high cube, will require external cooling hardware, and on site will need to be surrounded by concrete berms for shielding. (Once we finally see their proposed design.)

-Jon

 

[gadfly56]

I bet that they will just barely fit in a 53 foot long high cube, will require external cooling hardware, and on site will need to be surrounded by concrete berms for shielding. (Once we finally see their proposed design.)

-Jon

I'm not sure that "fits in a shipping container" means "operates from a shipping container". I took it as a simple way of indicating the size of the unit in terms folks would immediately understand.

 

[winnie]

I'm not sure that "fits in a shipping container" means "operates from a shipping container". I took it as a simple way of indicating the size of the unit in terms folks would immediately understand.

I agree. Think about a containerized diesel genset. Great thing; a truck can drive it from the factory and plop it down onto a pad. But you still need the appropriate infrastructure for the unit.

In the same way I can see tremendous benefit to a system where the entire containment and thermal to electrical conversion system is contained in a box that fits on to a truck. Shipped fully fueled and ready to slot into site infrastructure. When the fuel charge is consumed it gets moved to the side of the lot for a few years and then shipped back to the factory for refurbishment and refueling.

It doesn't really make a difference if the unit is a standard cube or a high cube, or if it is 20', 40', or 53' long. It is one truckload. I believe that the 'fits in a shipping container' is not only a description of size, but part of the actual plan; a modular unit containing the core systems (nuclear 'steam' generator, turbine, alternator) that can be shipped as a standard 'truckload'. (Noting that 'steam' production really means hot Helium.)

-Jon

 

[gadfly56]

I agree. Think about a containerized diesel genset. Great thing; a truck can drive it from the factory and plop it down onto a pad. But you still need the appropriate infrastructure for the unit.

In the same way I can see tremendous benefit to a system where the entire containment and thermal to electrical conversion system is contained in a box that fits on to a truck. Shipped fully fueled and ready to slot into site infrastructure. When the fuel charge is consumed it gets moved to the side of the lot for a few years and then shipped back to the factory for refurbishment and refueling.

It doesn't really make a difference if the unit is a standard cube or a high cube, or if it is 20', 40', or 53' long. It is one truckload. I believe that the 'fits in a shipping container' is not only a description of size, but part of the actual plan; a modular unit containing the core systems (nuclear 'steam' generator, turbine, alternator) that can be shipped as a standard 'truckload'. (Noting that 'steam' production really means hot Helium.)

-Jon

I'm not sure about that. I went to their web site looking for a schematic for the power production cycle and couldn't find anything. I don't think the helium is driving the turbines directly. Typical nuclear power production consists of a loop in the core and an external loop with a heat exchanger between the two loops. Heat is transferred from the primary loop to the power loop through the heat exchanger. This minimizes environmental exposure if there is a problem in the primary loop.

 

[winnie]

Good point. They make it clear that they use Helium as their primary coolant, but they _probably_ have a secondary loop powering their turbines.

On the other hand one of the goals is to operate at higher temperature permitting greater thermal efficiency, so they may be planning to use some other thermal loop to run the alternator.

Their website doesn't provide _any_ technical information as far as I can see.

Jon

 

[gadfly56]

Good point. They make it clear that they use Helium as their primary coolant, but they _probably_ have a secondary loop powering their turbines.

On the other hand one of the goals is to operate at higher temperature permitting greater thermal efficiency, so they may be planning to use some other thermal loop to run the alternator.

Their website doesn't provide _any_ technical information as far as I can see.

Jon

Well, helium would be a good way to get the core operating at a higher temperature. Once you get hot enough, water dissociates no matter what the pressure. Running a stochiometric mixture of H2 and O2 though your piping strikes me a tempting fate. On the other hand, you have to get to about 2,200 C to do this. I'm guessing there are other operational issues that limit steam temperatures in the primary loop.

 

[winnie]

The interview linked in a previous post has the CEO saying that they use Helium as a coolant. So we don't have to guess on their primary coolant.

-Jon

 

[drcampbell]

... Typical nuclear power production consists of a loop in the core and an external loop with a heat exchanger between the two loops. Heat is transferred from the primary loop to the power loop through the heat exchanger. This minimizes environmental exposure if there is a problem in the primary loop.

You're describing the typical pressurized-water reactor. (PWR)

https://www.nrc.gov/reading-rm/basic-ref/students/for-educators/04.pdf

There's also a typical boiling-water reactor (BWR) that transfers steam directly from the reactor to the turbine.

https://www.nrc.gov/reading-rm/basic-ref/students/for-educators/03.pdf

 

[gadfly56]

You're describing the typical pressurized-water reactor. (PWR)

https://www.nrc.gov/reading-rm/basic-ref/students/for-educators/04.pdf

There's also a typical boiling-water reactor (BWR) that transfers steam directly from the reactor to the turbine.

https://www.nrc.gov/reading-rm/basic-ref/students/for-educators/03.pdf

Good point, I had forgotten that. Wiki et al says that about 1/3 of US reactors are BWR and the remainder are PWR.

 

[yesterlectric]

It’s a ways out but I think if they are going to consider a new NEC article one day for this, it should be based on if there’s substantiation for it. If there’s other standards effectively protecting the public, may not be needed for the NEC to get into it. Not every hazard that exists is mitigated by an adopted building code and a local inspector tasked with enforcement. Not every safety hazard is solved by a UL standard either.

 

[drcampbell]

Electrical hazards are just the tip of the iceberg.
Nuclear criticality, high-pressure steam and leftover radionuclides are WAY more hazardous than electricity. ASME & NRC codes & standards will also be applicable.

 

[gadfly56]

It’s a ways out but I think if they are going to consider a new NEC article one day for this, it should be based on if there’s substantiation for it. If there’s other standards effectively protecting the public, may not be needed for the NEC to get into it. Not every hazard that exists is mitigated by an adopted building code and a local inspector tasked with enforcement. Not every safety hazard is solved by a UL standard either.

Other than the outlets in the plant office, the NEC doesn't cover anything else in a power plant, why would a nuclear plant be different?

 

[yesterlectric]

Other than the outlets in the plant office, the NEC doesn't cover anything else in a power plant, why would a nuclear plant be different?

That’s a good question. Not one for me. This post started with someone saying that we will soon need an NEC article for it.

 

[Dzboyce]

Interesting article in today's Seattle newspaper

The newest generation of nuclear power plants is taking shape in Washington state. These smaller reactors could provide flexible power free of direct carbon emissions. But a perilous nuclear history and big questions over safety remain. https://www.seattletimes.com/seattl...for-washington-state-can-it-change-the-world/

 

[drcampbell]

Other than the outlets in the plant office, the NEC doesn't cover anything else in a power plant, why would a nuclear plant be different?

Maybe because it's a portable generator set?

 

[gadfly56]

Maybe because it's a portable generator set?

OK, good one!

 

[ramsy]

It seams Great Britain's net zero plan will include 20% nuclear from Rolls Royce Small Modular Reactors (SMR).

Rolls-Royce launches nuclear reactor business

UK aircraft engine maker Rolls-Royce on Tuesday launched plans to build small low-cost nuclear reactors to help cut the nation's carbon emissions.

techxplore.com

No details in this article, but Wiki shows SMR's up to 1GW are not necessarily a pebble-bed reactor design.

https://en.wikipedia.org/wiki/Small_modular_reactor

 

[gadfly56]

It seams Great Britain's net zero plan will include 20% nuclear from Rolls Royce Small Modular Reactors (SMR).

Rolls-Royce launches nuclear reactor business

UK aircraft engine maker Rolls-Royce on Tuesday launched plans to build small low-cost nuclear reactors to help cut the nation's carbon emissions.

techxplore.com

No details in this article, but Wiki shows SMR's up to 1GW are not necessarily a pebble-bed reactor design.

https://en.wikipedia.org/wiki/Small_modular_reactor

It seems to me that 1GW is really pushing the definition of "small"!

 

[winnie]

It seems to me that 1GW is really pushing the definition of "small"!

As long as it fits in my DeLorean, I'm happy to call it small.

 

[drcampbell]

It seems to me that 1GW is really pushing the definition of "small"!

When the typical nuclear powerplant generates 600 MW_(e) and contains 100 tons of fuel rods, something that generates 1 MW(e) and weighs less then 40 tons* definitely qualifies as "small".

* just guessing about its weight, based on "fits on a truck".