Skip to main content

Currently Skimming:

6 Nuclear Criticality Considerations
Pages 58-64

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 58...
... However, the public concerns and political consequences could be very large; thus, the pane} has addressed the question in some detail. CRITICALITY ISSUES IN PROCESSING Nuclear criticality safety considerations provide significant restrictions to the process designs to be implemented for each of the processing options.
From page 59...
... Remove solid UFO Redistribute existing Apply batch/mass deposits material to critical limits configuration Accumulate external critical mass Ingress of water or other moderator Remove to favorable geometry containers Strict control of moderator sources
From page 60...
... Remove salt as liquid for fluorination elsewhere 7. Remove salt as solid Accumulate external critical mass Ingress of water or other moderator Redistribution or precipitation of uranium or plutonium Uranium redistribution, segregation, or precipitation to form critical mass Ingress of water or other moderator Ingress of water or other moderator Collapse of solid Remove to favorable geometry containers Strict control of moderator sources Fluorinate carefully with HE, followed by F2 Apply batch/mass limits Remove to favorable geometry containers Analyze and establish controls for new external systems Strict control of moderator sources Control geometry and/or mass of removed liquid material Strict control of moderator sources Salt removal procedures to stabilize geometry and prevent collapse
From page 61...
... over the last several decades 61 Strict control of sources of water and other moderators (or apply limits and/or geometries that accommodate optimum moderation) Apply batch/mass limits and/or use favorable geometry containers NOTE: F2 = molecular fluorine; HE = hydrogen fluoride; NaF = sodium fluoride; 0RNL = Oak Ridge National Laboratory; U = uranium; UFO = uranium hexafluoride; U3O~ = uranium oxide.
From page 62...
... Without as good moderation as in the graphite core, and with reduced uranium content (each drain tank originally contained only approximately half the uranium inventory, and more than 10 percent of that has migrated out of the salt) , the probability of a criticality excursion in each drain tank is further reduced.
From page 63...
... This containment system was designed for an operating reactor and thus should contain any plausible criticality excursion in the drain tanks. A comparison of the MSRE drain tank system to that of previous criticality accidents provides perspective.
From page 64...
... , and the presence of significant containment barriers. Detailed analyses of credible uranium and salt configurations are continuing at Oak Ridge National Laboratory (ORNL)


This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.