tag:blogger.com,1999:blog-7052664910047687823.post3883773259738153463..comments2023-06-10T08:52:45.988-07:00Comments on Evergreen Nuclear: Did Seismic Ground Motion Cause a Flux Spike Big Enough to Trip North Anna?Dr. John H. Bickelhttp://www.blogger.com/profile/04308245031594321790noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-7052664910047687823.post-69047401065948921972012-08-20T09:48:01.924-07:002012-08-20T09:48:01.924-07:00Can you find and report on 9/11 seismic spikes and...Can you find and report on 9/11 seismic spikes and why in 2008 did the only reporting science guy on 9/11 get an award "Urban Earthquakes, Nuclear Bombs and 9/11" seismic spikes are Nuclear Bombs and so Urban Earthquakes now called Nuclear Bombs in Urban areas by god knows who. 911Redpillhttps://www.blogger.com/profile/05030152459700598744noreply@blogger.comtag:blogger.com,1999:blog-7052664910047687823.post-26362444559763810962011-11-05T09:24:17.142-07:002011-11-05T09:24:17.142-07:00avantage certification itil
"anxiété de test&...<a href="http://www.articles4technology.info/2011/10/quels-sont-les-avantages-dune.html" rel="nofollow">avantage certification itil</a><br /><a href="http://www.articles4technology.info/2011/10/guide-praxis-etude-ii-controler.html" rel="nofollow">"anxiété de test"</a>Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7052664910047687823.post-1353836380243941612011-09-15T10:32:07.595-07:002011-09-15T10:32:07.595-07:00When trying to figure out what happened I usually ...When trying to figure out what happened I usually focus on the "most simple explanation". <br /><br />Since PWRs dynamically tend to be very sluggish in responding to higher frequency reactivity disturbances -- if one can quickly rule out that the reactor could amplify a seismic induced reactivity perturbation that pretty much leaves the source of a 10% power spike to be "instrumentation related". Shaking the detectors would be the simplest explanation in that regard. <br /><br />The only thing that could possibly transmit a reactivity disturbance in the 10-100 cycles/sec range that I could think of might be some form of "fuel rod bowing". But its hard to believe the fuel bundles - clamped and confined as they are could do this. They'd also be moving together rather than classical bowing caused by local heat-up (as was once observed in prototype fast reactors like EBR-1). I'm going to look into the magnitude of this one and try to also bound it.<br /><br />My money is currently on a seismic-induced instrumentation spike.Dr. John H. Bickelhttps://www.blogger.com/profile/04308245031594321790noreply@blogger.comtag:blogger.com,1999:blog-7052664910047687823.post-83058579464029089792011-09-13T10:28:31.616-07:002011-09-13T10:28:31.616-07:00Alright, verifying the effect on instrumention mea...Alright, verifying the effect on instrumention means addressing the question the other way around. So I guess, in order to falsify a significant relation between accelerations and in-core flow patterns, one will need a thermal-hydraulic test facility on a shake table:)<br /><br />Since findings from such an experiment would surely produce colourful pictures while contributing nothing to plant operations or safety, let's leave that to some well-funded artist like Christo or Koons.merkwuerdigliebehttps://www.blogger.com/profile/16766644823360911908noreply@blogger.comtag:blogger.com,1999:blog-7052664910047687823.post-87633858221841397682011-09-12T16:15:59.997-07:002011-09-12T16:15:59.997-07:00The quickest way to resolve the issue would be to ...The quickest way to resolve the issue would be to run a horizontal seismic "shake table" experiment with an energized ex-core neutron detector inside a metal pipe (to simulate a detector well). Excore neutron detectors - presumably such as BF3 type are run off high voltage. I am not certain of the specific units in use at North Anna but shaking the units, or hitting a detector against a detector well -- would all seem like good ways to generate a voltage spike.<br /><br />I am troubled to see Reuters and Dominion stating something which is un-physical:<br /><br />"Dominion officials said it now appears the reactors shut when the earthquake caused a problem inside the cores at both units rather than from the loss of outside power to the plant as initially reported."Dr. John H. Bickelhttps://www.blogger.com/profile/04308245031594321790noreply@blogger.comtag:blogger.com,1999:blog-7052664910047687823.post-21626034529262392182011-09-12T10:42:14.333-07:002011-09-12T10:42:14.333-07:00Thanks John, pretty informative post. Hottest gues...Thanks John, pretty informative post. Hottest guess probably is irritated instrumentation.<br /><br />Only now that we are sure that any periodic reactivity insertion wasn't amplified, I'm left wondering how to make a conservative quantitative estimate whether it may have been big enough to distort the flux pattern even without being amplified.<br /><br />In a BWR, I might indeed imagine some unexpected acceleration to cause a local void collapse or non-gravitational stratification resulting in locally abnormal flux changes. But as the water inventory in a PWR is rather incompressible (except for a little nucleate boiling maybe), there's no big effect on moderator density from acceleration. All the PWR-powered warships probably wouldn't even manage to leave the port if there were any. Deformation of core internals also appears rather far-fetched to me, given that they are supposed to keep their geometry in a LBLOCA.<br /><br />What are your suggestions on this issue?merkwuerdigliebehttps://www.blogger.com/profile/16766644823360911908noreply@blogger.com