[stankypickle]

Did we read the same article? To quote:

"Lyman believes that the department’s past efforts have “consistently underestimated”the “spectrum of mission risks posed by these microreactors," mostly around the technical challenges of keeping the radioactive fuel safe and operational in battlefield conditions.

“Fielding these reactors without commanders fully understanding the radiological consequences and developing robust response plans to cope with the aftermath could prove to be a disastrous miscalculation,” warned Lyman."

[luckylion]

That might be different for civilian use though. I don't know exactly what "battlefield conditions" means (airdropping it in? bullets hitting it?), but that's likely different if you're just aiming for decentral power generation but have safe ways to deploy and maintain.

[stankypickle]

It is being funded by the pentagon. It isn't for civilian use.

When considering "battlefield conditions" think along the lines of people with heat seeking missiles and infrared goggles who can easily spot a hot nuclear reactor, and who really want to bring down a base.

Not to mention how complicated it is to operate and maintain a nuclear reactor even if conditions are ideal. The additional training and personnel required to support one of these things... would it really be worthwhile in the end?

[pjc50]

"Battlefield conditions" means they need it to run the air conditioning in forward bases in occupied countries. At the moment, this is astonishingly expensive, because it has to be done with fuel trucked in across dangerous supply lines.

https://www.telegraph.co.uk/news/worldnews/northamerica/usa/... : every joule of energy spent on aircon in Afghansitan came from fuel trucked a thousand miles across the Khyber pass, getting shot at along the way. https://www.theguardian.com/world/2008/dec/08/afghanistan-ta...

[andromeduck]

If you're using enough power to warrant even a small nuclear reactor there's really no use trying to hide your thermals except maybe in a marine environment.

[swalsh]

I'd assume it's not about hiding the base, but more about hiding this glowing hot obvious target.

[luckylion]

Yes, this is about military use, I understood the comment from davidu to possibly not be focused on military use but about the idea in general, hence the difference between the positive lookout and yours (and the article's).

[stankypickle]

I'm not saying it isn't a bad idea for certain applications. I'm skeptical of the military application that is currently being pushed. It remains to be seen if one of these would even be plausible in the civilian arena, and the pentagon certainly isn't championing such (not that it should).

All of that just to power AC? Is the risk really worth the reward? Have the consequences of a failure in a military setting been fully considered?

[fredgrott]

battle conditions same spec for navy reactors on ships as ships generally face combat

[stankypickle]

Naval nuclear reactors are stored deep within the internal structure of the vessel (i.e. a negligible heat signature from the nuclear reactor is not visible from the outside). The proposed micro-reactor designs will vent the exhaust heat out into the open through an open Brayton cycle (i.e. it'll be really easy to spot).

Ships can be abandoned at sea with little risk because the nuclear material is likely to be unrecoverable. This is not true for reactors on land.

[arethuza]

Surely nuclear submarines must dump their heat into the surrounding water - it has to go somewhere?

[throwanem]

Sure. But the concern isn't about whether or not a nuclear-powered vessel can be identified as such; that information isn't really concealed, you'll have it as part of the same documentation that lets you ID a ship or submarine by class. The concern is about what happens when somebody drops a couple of mortar bombs on your land-based microreactor, or sets off a buried IED under it, or drives a VBIED into it.

[nradov]

Yes but water makes a very effective heat sink.