Russia working on space nuclear reactor

[Guest]

That will not be a problem when angara 5 replaces proton.

RCS and satellite engines still use it.

[xenomorph555]

RCS and satellite engines still use it.

Yeah but that wouldn't cause an environmental disaster like a proton would.

[YourEverydayWaffle]

It really depends on the reactor. The UK's CO2-cooled, graphite-moderated AGRs I have worked with enrich to about 3.5% (Although the enrichment varies per reactor, and for where in the core the fuel rod is going to go). Heavy water moderated reactors, like the CANDU, run on natural uranium.

The largest single-day dose I got was from working on a fuel build, and it was, if I remember correctly, 6 uSv. I don't know where you're living that's registering 15uSv/hr, but even on an airliner, you're usually looking at less than 1uSV/hr. You might want to check the calibration on your Geiger counter.

To put all of this into perspective, the lowest dose clearly linked to any increased risk of cancer is 100mSV. That's 100,000uSv.

Haha. That was a silly mistake of me. My memory doesn't always pick up the decimal point when I write it down. 1.4 uSv/h and 0.15 uSv/h background. Gotta love late-night post typing!

[NERVAfan]

The part of RORSAT (US-A) that terrifies me is that they considered an orbit with a thousand year decay to be 'good enough' for the graveyard. The cores will certainly not be rendered safe by then. Perhaps they just couldn't imagine any possible future where everyone WON'T be wearing radiation suits 24/7 in a thousand years? Or they're confident that in a thousand years snagging reactor cores from a decaying orbit and slinging them back out into space will be a trivial task for an unmanned ship? Both of those things MAY WELL be true... but still... the philosophy of handling a 50,000 year problem with a 1,000 year solution is a little unnerving.

I hope with this new wave of reactors that they plan to do something more farsighted at the end of life!

Hopefully it will just fall in the ocean somewhere, or Antarctica or something.

[magnemoe]

The part of RORSAT (US-A) that terrifies me is that they considered an orbit with a thousand year decay to be 'good enough' for the graveyard. The cores will certainly not be rendered safe by then. Perhaps they just couldn't imagine any possible future where everyone WON'T be wearing radiation suits 24/7 in a thousand years? Or they're confident that in a thousand years snagging reactor cores from a decaying orbit and slinging them back out into space will be a trivial task for an unmanned ship? Both of those things MAY WELL be true... but still... the philosophy of handling a 50,000 year problem with a 1,000 year solution is a little unnerving.

I hope with this new wave of reactors that they plan to do something more farsighted at the end of life!

Well its have two reasons, one is the cynical: they will not be around in 1000 years. Note that a 1000 year graveyard orbit is very secure compared to how they handled lots of the nuclear sub radiation problems as in dump in sea.

Second reason is more practical, in 1000 years it will either be trivial to fix this or we will have far larger problems.

[78stonewobble]

People are too liberal in the use of the word "disaster".

For completely arbitrary reasons I put the limit at 1.000 instant or connected deaths. Which is like 0,0000015 percent of the worlds population.

I would have put it at one percent of the worlds population or over 70.000.000 deaths, but then news agencies would run out of business.

[Nuke]

coal mine collapses and kills miners: cost of doing buisness

nuclear incident leads to a 1% increase in cancer risk: disaster

[Red Iron Crown]

coal mine collapses and kills miners: cost of doing buisness

nuclear incident leads to a 1% increase in cancer risk: disaster

Wind and solar each kill more than nuclear: It's green energy, and thus above rational criticism.

[Idobox]

The black funnelly thing on Topaz is a radiator, the actual reactor is just the bit at the very top. SNAP-10A used the same basic design.

I checked pictures, this thing is very black and devoid of fins for a heat radiator.

And I found a table giving electric power at 5 to 6.6 and 6kW for Topaz 1 and 2, compared to 150 and 160kW thermal, giving us an efficiency of 4.4 and 3.75%. Nuclear electricity is difficult in space.

russians seem to be pretty good with thermionic converters. less efficient than a brayton cycle, better than arrays of thermocouples.

Also much lighter than either. Vacuum tubes really kick ass for power applications