92020B3.MPB Chapter 2. Uranium Releasesto the Environment .. Operationsat SRS involve theuse of uraniumin both researchand productionareas. The isotopic compositionmay varybecauseuraniumthat hasbeen eitherenrichedor depletedin the_sU-isotope andnaturaluranium, which is nativeto the soil andwaterof the SRS, are presentoa the site. Uraniumon the site is presentin manychemical forms,such as the metallicuranium anduranium-aluminumalloy in fuel andtargetassemblies, varioussalts, such as uranylnitrateor uranylsulfate,presentin the separationsprocessstreams,and metal oxides (principallyUO3andU3Os)producedat the end of the separationsprocess. Small amountsof otherchemical forms are presenton the site for use in researchwork, primarilyat the SavannahRiver Laboratory(SRL). Naturallyoccurringuraniumis present in SRS soil andwaterprincipallyas metaloxides. Uraniumreleases haveoccurredprincipallyfromfuel fabricatior andspentfuel processing facilities. Smallerreleases have occurredfromwaste storageandresearchareas. These releases haveoccurredto the atmosphere,site streams,andthe ground.The majorityof these havebeen predictedreleases resultingfromsuch unavoidablesituationsas the natural imperfectionof filtrationmedia. This Chapterdescribesthe origins of documenteduraniumreleases andtheir routes tothe environment. These are releases thatwere anticipatedandwere measuredeitheras uraniumor as partof a gross.alphameasurement. Chapter2. Uranium Releasesto the Environment Specific Uranium Analysesand Unidentified Alpha Some SRS facilities that release uranium also release However,no attemptwas made to scale any data when dual plutonium and other transuranic alpha emitting analyses were not run because no consistent correlations radionuclides. Specific radiochemicalanalyses foruranium between thedata were found. were performed to distinguish uranium releases from releases of the more hazardous transuranium elements. In Mostof the release dataweretaken fromCummins, Hetrick, some facilities, wheresignificant releases of alpha-emitting and Martin, 1991,which summarizesSRS releasescovering radionuclides were not anticipated, only gross-alpha (also the period 1954 through 1989. called unidentified or unknown alpha) analyses were performed to provide an indication of the presence of Releases of radioactivity are expressed in curies. To unexpected alpha emitters. The release tables in this estimate thecorrespondingweightofreleased uranium,the Chapterindicate which values are derived fromuranium-specific activity for the given isotopic mixture must be specific radiochemical analyses and which were derived calculated.For the"natural"uranium(99.27%z_U, 0.7?'_ fromgross-alpha analyses, ln onefacility,theSRLseepage _U, and 0.0055% _U), this specific activity i,, basins, bothanalyses wereperformed overa 10-year period. 692nanocuries pergram(3190pou nds/curie). 1.7 x 10"_-curies.This is the equivalent of about 80 g of (J 4e-5 ,.o natural and depleted uranium during the time of the measurementsor, roughly, 6 rag/day 2e-5 M-Area Releasesto Streams

Biochar -charcoal used to amend land and sequester carbon -is attracting considerable interest. Its distinctive physical/chemical/biological properties, including high water-holding capacity, large surface area, cation exchange capacity, elemental composition and pore size/volume/distribution, effect its recognised impacts, especially on microbial communities. These are explored in the context of agriculture, composting and land remediation/restoration. Considerable focus is given to mycorrhizal associations, which are central to exploitation in environmental technologies involving biochar. The characteristics of biochar, its availability for nutrient cycling, including the beneficial and potentially negative/inhibitory impacts, and the requisite multidisciplinary analysis (physico-chemical, microbiological and molecular) to study these in detail, are explored.

The timing and duration of volcanism within each igneous province of the North Atlantic region during the Tertiary is required to evaluate possible relationships between this magmatism, plate tectonics and continental drift. Published radioisotopic dates from the British Tertiary volcanic province are listed and briefly reviewed in the context of the data available from other North Atlantic areas. New conventional K–Ar and 40 Ar/ 39 Ar age spectrum ages of rocks from Mull, Staffa, Arran, Antrim, the Mountains of Mourne, Carlingford, the Cleveland dyke and the North Welsh dyke swarm are reported. Volcanism began in the British Province around or just before 65–66 m.y. in the latest Cretaceous or earliest Palaeocene. The earliest episode of basalt lava eruption in Northern Ireland may not be represented in the Hebrides. The major plutonic centres are between 60 and 58 m.y. while minor activity continued at various localities until at least 50 m.y. in the Eocene.

Palaeomagnetic measurements and potassium-argon age determinations have been performed on two sequences of lava flows from the Banks Peninsula, New Zealand.Flows from the Stoddart Formation are entirely of reversed polarity and were formed rapidly at 5.85+0.04 My ago. The Akaroa sequence, extruded over a time interval from 9.1 to 8.4 My ago, records seven reversals of the Earth's magnetic field. The geomagnetic polarity time scale constructed from these results agrees well with the time scales postulated from the interpretation of magnetic anomaly patterns over mid-ocean ridges. The age of the polarity reversal terminating the normal period associated with Anomaly 5 is 8.67k0.13 My.

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