6 ms·

Here, I'll come up with a proposal. If Congress is serious about climate change, then they can ask (and allocate the budget) the Department of Energy to procure

Here, I'll come up with a proposal. If Congress is serious about climate change, then they can ask (and allocate the budget) the Department of Energy to procure and operate a bunch of naval nuclear reactors. With whatever internal regulations they have, the US Navy has not had a single incident in their entire history of operating nuclear reactors. They are also quite cost effective, for example the cost of the 2 reactors A1B [1] that power a Gerald Ford carrier is about $1 BN. That comes to about $2BN/GW, which is about a tenth of what a civilian reactor costs. The US Navy builds about 1 carrier every 4 years so that comes to 1 reactor every other year. If the DoE gets the Congressional mandate to procure a few reactors per year, the cost is going to surely come down. Also these reactors don't need refueling for about 2 decades, while civilian reactors are refueled every 1.5 years. [1] https://en.wikipedia.org/wiki/A1B_reactor https://en.wikipedia.org/wiki/A1B_reactor

philipkglass 6y ago
The US stockpile of HEU would be depleted a lot faster this way, but enrichment could start again. I don't see major downsides to this proposal. Thanks for providing a specific and plausible idea!
Hammershaft 6y ago
Thats a great idea. I'm trying and failing to find gotchas.
- credit_guy 6y ago
  There is a potential gotcha: proliferation potential. The naval reactors use highly enriched uranium; if it falls in the wrong hands, you can end up with someone being able to build a bomb. That's why I said such a program needs to be run by the Department of Energy, the same department that has to maintain the nukes. I don't have a personal objection to this, but a lot of people would be unhappy with an essentially military program to be established for a problem that is not military in nature.
  - obelos 6y ago
    Hopefully the DOE will continue to be led by a person who didn't previously campaign on disbanding it!
sir_bearington 6y ago
This is not a very good idea for several reasons. Naval reactors require fuel that is much more enriched than normal reactors. They also produce significantly lower electricity. The Palo Verde facility produces 3GW of electricity and cost $11B in 2019 dollars. Each of the A1B reactors generates 125 MW. Life span of the reactor is not specified, but it's predecessor the A4W had a 23 year life span. By comparison, new nuclear plants are slated to last 50-80 years. The net cost per GWh of electricity of the naval reactor is significantly worse than commercial plants. This is to be expected, because naval reactors are built to be compact and withstand the rocking of a ship at sea. Commercial reactors can leverage the efficiency of larger scale, and are built to be much more long lasting.
- credit_guy 6y ago
  An A1B generates 125 MW electricity, but also 260 MW of additional thermal power used to power the propellers. If you convert the latter one to electricity at a 45% efficiency (typical efficiency for a generation IV nuclear power plant steam turbine), you get 117 MW, for a total of 242 MW. Two reactors could produce then about 0.5 GW. At a $1 BN cost, that's $2 BN / GW. Palo Verde was brought online more than 30 years ago. If you look at Vogtle 3-4 (to be brought online in the next 2 years... if we are lucky) or Hinkley Point C, you'll see projected costs of respectively $25 BN for 2.5 GW and $32 BN for 3.2 GW. In both cases that comes at $10 BN/ GW. That is 5 times more expensive than the naval reactor. Now, as you said, the cost of a naval reactor is very likely inflated by the exacting demands of its military usage. It needs to be compact, to work on a rocking ship, presumably it needs to be able to survive a certain amount of abuse that's to be expected if a ship/boat actually participates in combat, and I'm sure there are 100 other things that I'm missing here. All these factors make military devices absurdly expensive compared to the same devices intended for civilian use. The logical conclusion is that if DoE wants to repurpose naval reactors for civilian use, then it can achieve significant cost savings. What I'm saying is that even not factoring these savings in, you still end up 5 times cheaper than the civilian reactors that are currently being built. Edit: The lifespan of a Gerald Ford-class carrier is expected to be 50 years. The Nimitz aircraft carrier was launched 49 years ago. They do not replace their reactors. So, a naval reactor is designed to work for at least 50 years.

philipkglass 6y ago

The US stockpile of HEU would be depleted a lot faster this way, but enrichment could start again. I don't see major downsides to this proposal. Thanks for providing a specific and plausible idea!

Hammershaft 6y ago

Thats a great idea. I'm trying and failing to find gotchas.

credit_guy 6y ago
There is a potential gotcha: proliferation potential. The naval reactors use highly enriched uranium; if it falls in the wrong hands, you can end up with someone being able to build a bomb. That's why I said such a program needs to be run by the Department of Energy, the same department that has to maintain the nukes. I don't have a personal objection to this, but a lot of people would be unhappy with an essentially military program to be established for a problem that is not military in nature.
- obelos 6y ago
  Hopefully the DOE will continue to be led by a person who didn't previously campaign on disbanding it!

sir_bearington 6y ago

This is not a very good idea for several reasons. Naval reactors require fuel that is much more enriched than normal reactors. They also produce significantly lower electricity. The Palo Verde facility produces 3GW of electricity and cost $11B in 2019 dollars. Each of the A1B reactors generates 125 MW. Life span of the reactor is not specified, but it's predecessor the A4W had a 23 year life span. By comparison, new nuclear plants are slated to last 50-80 years. The net cost per GWh of electricity of the naval reactor is significantly worse than commercial plants. This is to be expected, because naval reactors are built to be compact and withstand the rocking of a ship at sea. Commercial reactors can leverage the efficiency of larger scale, and are built to be much more long lasting.

credit_guy 6y ago
An A1B generates 125 MW electricity, but also 260 MW of additional thermal power used to power the propellers. If you convert the latter one to electricity at a 45% efficiency (typical efficiency for a generation IV nuclear power plant steam turbine), you get 117 MW, for a total of 242 MW. Two reactors could produce then about 0.5 GW. At a $1 BN cost, that's $2 BN / GW. Palo Verde was brought online more than 30 years ago. If you look at Vogtle 3-4 (to be brought online in the next 2 years... if we are lucky) or Hinkley Point C, you'll see projected costs of respectively $25 BN for 2.5 GW and $32 BN for 3.2 GW. In both cases that comes at $10 BN/ GW. That is 5 times more expensive than the naval reactor. Now, as you said, the cost of a naval reactor is very likely inflated by the exacting demands of its military usage. It needs to be compact, to work on a rocking ship, presumably it needs to be able to survive a certain amount of abuse that's to be expected if a ship/boat actually participates in combat, and I'm sure there are 100 other things that I'm missing here. All these factors make military devices absurdly expensive compared to the same devices intended for civilian use. The logical conclusion is that if DoE wants to repurpose naval reactors for civilian use, then it can achieve significant cost savings. What I'm saying is that even not factoring these savings in, you still end up 5 times cheaper than the civilian reactors that are currently being built. Edit: The lifespan of a Gerald Ford-class carrier is expected to be 50 years. The Nimitz aircraft carrier was launched 49 years ago. They do not replace their reactors. So, a naval reactor is designed to work for at least 50 years.