Deutsch   English   Français   Italiano  
<6ajnkj17gre1jpcs0cn6692d6kem6ficor@4ax.com>

View for Bookmarking (what is this?)
Look up another Usenet article

Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: john larkin <JL@gct.com>
Newsgroups: sci.electronics.design
Subject: Re: New fusion power system test creates 300,000 degrees C plasma
Date: Sat, 30 Nov 2024 18:57:58 -0800
Organization: A noiseless patient Spider
Lines: 106
Message-ID: <6ajnkj17gre1jpcs0cn6692d6kem6ficor@4ax.com>
References: <vicmgh$j28b$1@solani.org> <vid5og$17b08$1@dont-email.me> <1r3svpl.148oh3818kksy4N%liz@poppyrecords.invalid.invalid> <vidafk$18c6s$1@dont-email.me> <1r3t0yh.1en723hd56invN%liz@poppyrecords.invalid.invalid> <vidf2k$1933l$1@dont-email.me> <1r3tx4d.i621141x40wlcN%liz@poppyrecords.invalid.invalid> <vieqs4$1lb23$2@dont-email.me> <uohmkj55an5qsvsdmbj1agobke839p65na@4ax.com> <vifrbt$1tvm0$1@dont-email.me> <262nkj16um51ookln94nvfun2j2e6i8p0l@4ax.com> <vig4sj$1voo8$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Injection-Date: Sun, 01 Dec 2024 03:58:02 +0100 (CET)
Injection-Info: dont-email.me; posting-host="6b8552caf086e8e7aa172ace79959eaa";
	logging-data="2197759"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX19oP2uMNZDFjjTrrJN7k2f2"
User-Agent: ForteAgent/8.00.32.1272
Cancel-Lock: sha1:EIsjSGUwcGn7SbeJAhFwk5Hd7Fc=
Bytes: 5507

On Sat, 30 Nov 2024 23:54:54 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:

>On 11/30/24 22:59, john larkin wrote:
>> On Sat, 30 Nov 2024 21:12:23 +0100, Jeroen Belleman
>> <jeroen@nospam.please> wrote:
>> 
>>> On 11/30/24 18:19, john larkin wrote:
>>>> On Sat, 30 Nov 2024 11:57:50 +0100, Jeroen Belleman
>>>> <jeroen@nospam.please> wrote:
>>>>
>>>>> On 11/30/24 10:34, Liz Tuddenham wrote:
>>>>>> Jeroen Belleman <jeroen@nospam.please> wrote:
>>>>>>
>>>>>>> On 11/29/24 23:03, Liz Tuddenham wrote:
>>>>>>>> Jeroen Belleman <jeroen@nospam.please> wrote:
>>>>>>>>
>>>>>>>>> On 11/29/24 21:04, Liz Tuddenham wrote:
>>>>>>>>>> Jeroen Belleman <jeroen@nospam.please> wrote:
>>>>>>>>>>
>>>>>>>>>> [...]
>>>>>>>>>>> It would be lovely to have 50kWTh or so of PU238 in the basement,
>>>>>>>>>>> if it could be made cheaply enough. Power for a lifetime for the
>>>>>>>>>>> whole house and then some.
>>>>>>>>>>
>>>>>>>>>> ...but the lifetime might not be very long if any got out.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> If, if. Such arguments can be used to prove anything.
>>>>>>>>>
>>>>>>>>> I've got a diesel-powered car in the basement garage. Fully tanked,
>>>>>>>>> it contains 60kg of fuel, good for 2.4GJ or so. Imagine the havoc
>>>>>>>>> that could cause, if it got loose. For reference, a stick of dynamite
>>>>>>>>> is about 1MJ.
>>>>>>>>
>>>>>>>> I've seen what happened when builders accidentally set fire to a tank of
>>>>>>>> diesel far bigger than that.  It burned slowly and steadily until it set
>>>>>>>> fire to the roof of the house - then the house burned down.  Nobody was
>>>>>>>> injured or killed, the mess was easily cleaned up and a new house built
>>>>>>>> on the site.
>>>>>>>>
>>>>>>>> It wasn't like the sudden release of energy you would get in a fuel-air
>>>>>>>> explosion (quite difficult to initiate with diesel without specialist
>>>>>>>> knowledge) and there wasn't a lot of residual toxic contamination.
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> OK. Now back to small 238Pu fuelled units. Why would you expect
>>>>>>> anything to go wrong if the Pu was contained in a hermetic canister?
>>>>>>
>>>>>> There's always an idiot (or a terrorist) who would challenge themself to
>>>>>> open it.
>>>>>>
>>>>>>
>>>>>
>>>>> Yes, probably. There have been similar incidents in the past.
>>>>> I'm convinced it can be made safe enough for widespread normal
>>>>> use, but there will always be some fool somewhere. If we let
>>>>> that stop us, no technology is safe enough.
>>>>>
>>>>> Jeroen Belleman
>>>>
>>>> A kilogram, properly distributed, would make a city uninhabitable for
>>>> centuries. Imagine such an active alpha emitter in a water supply.
>>>
>>> There are myriad ways to create havoc, if we wanted to. I have castor
>>> plants in the garden. They are very decorative. Properly distributed,
>>> there is enough ricin in them to kill tens of thousands of people.
>>> Nobody cares. Weaponizing noxious substances isn't so easy.
>>>
>>>>
>>>> It would make some cool glow-in-the-dark gadgets.
>>>>
>>>> Critical mass is around 10 Kg. Kids could make nukes.
>>>>
>>>
>>> 238Pu doesn't sustain a chain reaction, at least not in the quantities
>>> we talk about. Nukes use 239Pu, the fissionable isotope. That's the
>>> isotope that has a critical mass in the 10kg ballpark. Even then, it's
>>> *very* hard to keep it together for long enough to create a sizable
>>> explosion. No kid is going to pull that off, even if he could get his
>>> hands on 239Pu in sufficient amounts.
>>>
>>> Jeroen Belleman
>> 
>> Wiki claims
>> 
>> https://en.wikipedia.org/wiki/Plutonium-238
>> 
>> 10 Kg critical mass. Are they wrong?
>> 
>
>I think so.
>
>Jeroen Belleman

Googling has many references and some papers, all around 10 Kg
unshielded, half that with a good neutron reflector.

I suppose something that doesn't normally emit neutrons can still
fission, from a cosmic ray or something.

All 5 plutonium isotopes have a critical mass, at which point I assume
that Something Bad happens.