Fission news(I know blasphemy )

Point out news stories, on the net or in mainstream media, related to polywell fusion.

Moderators: tonybarry, MSimon

paperburn1
Posts: 2313
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Fission news(I know blasphemy )

Postby paperburn1 » Fri Feb 24, 2017 4:36 am

I guess it is all relative, not huge like Fukushima but huge in comparison to the cost of a normal cleanout/up.
I am not a nuclear physicist, but play one on the internet.

D Tibbets
Posts: 2774
Joined: Thu Jun 26, 2008 6:52 am

Re: Fission news(I know blasphemy )

Postby D Tibbets » Fri Feb 24, 2017 5:51 am

KitemanSA wrote:
paperburn1 wrote:...There will still be huge cost associated with cleanup ...

Seems highly unlikely since any leakage would either freeze on the leak, plugging it, or drip to the floor where it would freeze and be easily chipped and swept then hit with the nuclear equivalent of a Stanley Steemer.


Yes and no... Even fuel rods my end up as solid chunks, at least those ejected from the immediate vicinity of the meltdown. The decay products are essentially unchanged, and the isotopes that are gasses- like Xenon and iodine (derived from xenon?) and other isotopes that are originally gasous or forms gassous or liquid compounds with reaction with air or other substances- that is gasses at near STP (room temperature and pressure).

The dynamics change, but the need for containment and cleanup / entombment doesn't. The most obvious advantages is that you do not have a molten core sinking into bedrock or (hopefully) no radioactive chunks and dust scattering outside the containment building.

And, come to think of it, I believe the Fukushima reactors had basement vaults, that the melted core/ debris sank into. This may have been somewhat similar to the drain plug idea in a liquid salt reactor. The details are different but final result may be the same. Except, of course, the basement vault only came into play after meltdown, and probably after atmospheric containment failure. Things the molten salt reactor would hopefully circumvent through better design and before the runaway heat buildup compounded the problems. I haven't heard if any of the meltdowns penetrated the basement vaults.

Dan Tibbets
To error is human... and I'm very human.

ladajo
Posts: 6153
Joined: Thu Sep 17, 2009 11:18 pm
Location: North East Coast

Re: Fission news(I know blasphemy )

Postby ladajo » Fri Feb 24, 2017 9:39 pm

In the Fukishima design the last line of defense is a large bathtub of re-enforced concrete plant foundation that forms a collection well for any slag (corium) that penetrates the other (roughly four) boundaries. In that design, the main line of defense for total core failure is this well, which is the boundary before the foundation bucket. One of the issues with the design of older pressure vessels, inherent to being a pressure vessel, is that the bottom is concave for the molten fuel mass (slag), which in turn concentrates it, improving reactivity and heat focus. This in turn can cause the vessel to fail, and then you are looking for a well containment, which may not disperse the slag sufficiently. I always wondered back in the day, why the containment engineers allowed for concave designs, it seemed counter to the goal. However, I think they were victims of hubris regarding the ability to keep a core assembly from slagging. Meh.

Edit for clarity.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

paperburn1
Posts: 2313
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Fission news(I know blasphemy )

Postby paperburn1 » Sat Feb 25, 2017 11:33 pm

Speaking of hubris, One of the little-known facts about fukushima was the generators were sealed in a watertight building in the flood zone. In theory even if submerged underwater the buildings retain their integrity and in fact they did. But it was a small little overlooked design flaw that did the reactor in. The power conduit for the wiring from the generator building to the pumps in the reactor were not watertight. As the water level rose it found its way into the generators through the conduit used to supply power to the motors. For $100 of sealant the disaster would have never happened. But those at the built the generators shed assumed the sealing what occurred at the reactor side and those at the reactor side assumed the sealing would occur at the entry point into the watertight shed. oops!
I am not a nuclear physicist, but play one on the internet.

ladajo
Posts: 6153
Joined: Thu Sep 17, 2009 11:18 pm
Location: North East Coast

Re: Fission news(I know blasphemy )

Postby ladajo » Sat Feb 25, 2017 11:57 pm

Hadn't heard that one. Funny, and totally believable. Do you have a cite handy? No worries if you don't. Just curious.

One of the ironies for me is that the Fukishima design is from the same era as TMI, and both were done in by H2 after frying the cladding.
One would think there would have been more thought put into procedural and plant safety revisions. I am out of the loop now, however I do wonder on occasion the design repercussions from the multiple H2 excursions. Granted those old designs are moot, however I would like to think that new designs are being held accountable. Maybe I should look into it. Meh. When I get some time, maybe. Got bigger and more frightful fish to fry these days.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)

What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

paperburn1
Posts: 2313
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Fission news(I know blasphemy )

Postby paperburn1 » Sun Feb 26, 2017 1:20 am

On 11 March 2011 Japan suffered its worst recorded earthquake. The epicentre was 110 miles east north
east from the of the Fukushima Dai‐ichi (Fukushima‐1) nuclear power site which has 6 Boiling Water
Reactors. Reactor Units 1, 2 and 3 on this site were operating at power before the event and on detection
of the earthquake shut down safely. Initially 12 on‐site back diesel generators were used to provide the
alternating (AC) electrical supplies to power essential post‐trip cooling. Within an hour a massive tsunami
from the earthquake inundated the site. This resulted in the loss of all but one diesel generator, some
direct current (DC) supplies and essential instrumentation, and created massive damage around the site.
Despite the efforts of the operators eventually back‐up cooling was lost. With the loss of cooling systems,
Reactor Units 1 to 3 overheated. This resulted in several explosions and what is predicted to be melting of
the fuel in the reactors leading to major releases of radioactivity, initially to air but later by leakage of
contaminated water to sea.  
http://www.onr.org.uk/fukushima/final-report.pdf
Japanese earthquake and tsunami:
Implications for the UK nuclear industry
Final Report
HM Chief Inspector of Nuclear Installations
September 2011
I am not a nuclear physicist, but play one on the internet.

ladajo
Posts: 6153
Joined: Thu Sep 17, 2009 11:18 pm
Location: North East Coast

Re: Fission news(I know blasphemy )

Postby ladajo » Sun Feb 26, 2017 1:43 am

I have read several findings reports on the accident, and knew that the backup gensets had flooded via the cable conduits, however I did not know that they were specked for sealants, and it was not done. I am sorry, I should have clarified. Thanks though!
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)

What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

paperburn1
Posts: 2313
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Fission news(I know blasphemy )

Postby paperburn1 » Sun Feb 26, 2017 3:20 am

I will see if I can find that report,this might be it. http://www.epri.com/abstracts/Pages/Pro ... 0001024946
It was under lessons learned or something like that. Most of the generators were washed away but if the ones in the "basement" had been water tight they think it would have been a non event like the other reactors that successfully shut down that day.
I am not a nuclear physicist, but play one on the internet.

KitemanSA
Posts: 6113
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: Fission news(I know blasphemy )

Postby KitemanSA » Sun Feb 26, 2017 6:30 am

D Tibbets wrote:
KitemanSA wrote:
paperburn1 wrote:...There will still be huge cost associated with cleanup ...

Seems highly unlikely since any leakage would either freeze on the leak, plugging it, or drip to the floor where it would freeze and be easily chipped and swept then hit with the nuclear equivalent of a Stanley Steemer.
Yes and no... Even fuel rods my end up as solid chunks,
I've been talking about molten salt reactors, specifically Liquid Fluoride Thorium Reactors (LFTRs). No "fuel rods" in LFTRs.

KitemanSA
Posts: 6113
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: Fission news(I know blasphemy )

Postby KitemanSA » Sun Feb 26, 2017 6:33 am

paperburn1 wrote:Speaking of hubris, One of the little-known facts about fukushima was the generators were sealed in a watertight building in the flood zone. In theory even if submerged underwater the buildings retain their integrity and in fact they did. But it was a small little overlooked design flaw that did the reactor in. The power conduit for the wiring from the generator building to the pumps in the reactor were not watertight. As the water level rose it found its way into the generators through the conduit used to supply power to the motors. For $100 of sealant the disaster would have never happened. But those at the built the generators shed assumed the sealing what occurred at the reactor side and those at the reactor side assumed the sealing would occur at the entry point into the watertight shed. oops!

Wouldn't have helped since all the switch gear from the EDG to all the reactor emergency equipment was located in the basement of the turbine building which was NOT watertight.

KitemanSA
Posts: 6113
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: Fission news(I know blasphemy )

Postby KitemanSA » Sun Feb 26, 2017 6:37 am

paperburn1 wrote:On 11 March 2011 Japan suffered its worst recorded earthquake. The epicentre was 110 miles east north
east from the of the Fukushima Dai‐ichi (Fukushima‐1) nuclear power site which has 6 Boiling Water
Reactors.
Turns out that Onagawa Nuclear Power Station was closer to the epicenter, saw greater shaking and a higher tsunami and was just fine. Indeed, Onagawa served as a refugee center for tsunami displaced villiagers from the area.

paperburn1
Posts: 2313
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Fission news(I know blasphemy )

Postby paperburn1 » Sun Feb 26, 2017 12:43 pm

Please note this was at a reactor were TEPCO followed the seawall and power distribution recommendations. The fukushima reactors the largest difference between them, apart from the reactor safety systems being designed some twenty years apart, the Fukushima I seawall was built to a height of just 5.7m. Whilst the Onagawa power plant seawall was nearly 14 m (46 ft) high and thus successfully blocked the majority of the tsunami from causing severe flood damage and even though a lot of these deficiencies were later discovered before the tsunami the company chose not to upgrade fukushima.

That is the difference from doing it right and doing it to save money.
I am not a nuclear physicist, but play one on the internet.

KitemanSA
Posts: 6113
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: Fission news(I know blasphemy )

Postby KitemanSA » Thu Mar 02, 2017 7:05 am

paperburn1 wrote:Please note this was at a reactor were TEPCO followed the seawall and power distribution recommendations.
Onagawa is owned and operated by KEPCO IIRC, not TEPCO.

KitemanSA
Posts: 6113
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: Fission news(I know blasphemy )

Postby KitemanSA » Thu Mar 02, 2017 7:07 am

paperburn1 wrote:I guess it is all relative, not huge like Fukushima but huge in comparison to the cost of a normal cleanout/up.
Don't see why it woud be "huge in comparison" to anything.

D Tibbets
Posts: 2774
Joined: Thu Jun 26, 2008 6:52 am

Re: Fission news(I know blasphemy )

Postby D Tibbets » Thu Mar 02, 2017 4:53 pm

KitemanSA wrote:
D Tibbets wrote:
KitemanSA wrote:Seems highly unlikely since any leakage would either freeze on the leak, plugging it, or drip to the floor where it would freeze and be easily chipped and swept then hit with the nuclear equivalent of a Stanley Steemer.
Yes and no... Even fuel rods my end up as solid chunks,
I've been talking about molten salt reactors, specifically Liquid Fluoride Thorium Reactors (LFTRs). No "fuel rods" in LFTRs.


Of course no fuel rods. That is not the point. What I was trying to relate is that as the molten salt plus the fission slag cooled it would solidify. This extremely radioactive slag would need to be cleaned up of entombed. Fuel rods are similar except more concentrated equivalent of this slag. They are hot but mostly solid- except for gasses that may be venting- same for liquid / solid salt slag. The fuel rods are handled normally by well established cool down and staged transfer methods to final storage. The radioactive salt slag is more messy in this regard. It is not contained in neat cladded containers which facilitate handling. In a melt down the fuel rods are compromised and things become very much messier. But the liquid salt sludge is also messier that normal fuel rod handling- clean up costs, just not as messy as the fuel rod design. Costs would be intermediate between a solid fuel rod design failure and a normal solid fuel rod handling scheme. Where on this range of costs it would fall is the arguable point. .

In the case of a catastrophic failure a liquid salt reactor with a drain reservoir is better, perhaps much better than a sold fuel rod design in terms of management and cleanup, but still much worse than normal fuel rod handling concerns in a functioning/ non failed conventional reactor.. It is an improvement but not a cure all. There are consequences if there is a failure, it is less severe, but the cost may still be considerable- loss of reactor, cleanup costs that may exceed the cost of the reactor, etc. The environmental consequences are what benefits the most from the claimed advantages of the liquid salt reactors. By avoiding most of the enviornmental consequences there are considerable political advantages and less financial risks.

Another consideration of molten salt reactors may be size scaling. Conventional fission reactors need to be about 1000 MW heat output to maximize output versus cost of the plant. If a liquid salt reactor lends itself to smaller output designs, a cascade of benefits- both operational and failure consequences and management may be attractive.

I am not preaching against liquid salt reactors, actually based on my limited knowledge, they seem an attractive alternative to conventional fission reactors. But, that does not mean they should be embraced without considerable skepticism and caution. There is no getting around the consequences of fissioning a uranium, plutonium, or thorium atom. Though, after saying that, I again must admit that improved processing of fission products for additional useful energy gain can change things considerably. But, this is mostly a separate issue from failure considerations.

Dan Tibbets
To error is human... and I'm very human.


Return to “News”

Who is online

Users browsing this forum: No registered users and 8 guests