?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F325%2F&rft.title=Gas+release+from+sludge&rft.creator=Brewster%2C+M.&rft.creator=Dellar%2C+P.&rft.creator=Entov%2C+V.&rft.creator=Fliert%2C+B.+vd.&rft.creator=Fowler%2C+A.&rft.creator=Grover%2C+B.&rft.creator=Hinch%2C+E.+J.&rft.creator=Lister%2C+J.&rft.creator=Ng%2C+F.&rft.creator=Schulze%2C+T.&rft.subject=Energy+and+utilities&rft.subject=Materials&rft.description=Nuclear+waste+in+the+form+of+sludge+of+rather+uncertain+composition+is+held+in+177+cylindrical+tanks%2C+typically+23m+in+diameter+and+10m+high.+The+radioactivity+splits+some+water+molecules+into+free+radicals%2C+which+are+thought+to+recombine+on+suitable+catalytic+sites+to+form+hydrogen+gas.+The+rate+of+production+of+gas+(hydrogen+and+other+species)+is+typically+about+4m%5E3%2Fday+in+the+SY-101+tanks.+When+the+concentration+of+hydrogen+in+the+roof+of+the+tank+exceeds+4%25%2C+there+is+a+risk+of+deflagration.+The+study+group+was+asked+to+consider+the+mode+in+which+the+gas+is+released%2C+whether+as+dangerous+large+eruptions+or+as+acceptable+continuous+background+release.+We+were+also+asked+how+much+gas+was+stored+in+the+sludge%2C+where+and+in+what+form.+The+sludge+is+neither+solid+nor+fluid%2C+but+rather+a+yield+material+with+a+yield+stress+of+about+103+Pa.%0D%0A%0D%0AThe+study+group+based+its+approach+on+a+video+produced+by+Pacific+Northwest+of+a+laboratory+experiment+in+which+gas+was+generated+in+a+yield+material.+In+these+experiments+oxygen+was+produced+from+hydrogen+peroxide%2C+and+the+material+was+a+clay+suspension.+The+video+showed+bubbles+growing+in+the+material%2C+and+the+height+of+the+sample+rising%2C+rather+like+baking+bread.+After+some+time%2C+some+bubbles+were+large+enough+to+overlap%2C+and+they+merged.+The+result+of+several+mergers+was+to+form+cracks%2C+fairly+horizontal%2C+which+grew+by+being+inflated+by+gas+and+then+breaking+sideways+into+a+nearby+bubble.+A+model+of+this+crack+growth+is+given+in+section+3.1.+Gas+was+released+to+the+surface+from+the+network+of+cracks.&rft.date=1996&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F325%2F1%2FGas-retention-and-release-mechanisms-in-tank-waste.pdf&rft.identifier=++Brewster%2C+M.+and+Dellar%2C+P.+and+Entov%2C+V.+and+Fliert%2C+B.+vd.+and+Fowler%2C+A.+and+Grover%2C+B.+and+Hinch%2C+E.+J.+and+Lister%2C+J.+and+Ng%2C+F.+and+Schulze%2C+T.++(1996)+Gas+release+from+sludge.++%5BStudy+Group+Report%5D+++++