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.

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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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Cesium in the Sa'_,annahRiver Site Environment is published as a part of the Radiological Assessment Program (RAP). lt is the fourth in a series of eight documents on individual radioisotopes released to the environment as aresult of Savannah River Site (SRS) operations. The earlier documents describe the environmental cortsequences of tritium, iodine, and uranium. Documents on plutonium,strontium, carbon, and technetium will be published in the future. These are dynamic documents andcurrent plans call for revising and updating each one on a two-year schedule. Radiocesium exists in the environment as aresult of above-ground nuclear weapons tests, the Chemobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operationof industrial, medical, andeducational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of _TCswas released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantifies were released from the fuel reprocessing operations. About 1400Ciof lrPCswas released to seepagebasins where it was tightly boundby clay in the soil. A much smallerquantity, about four Ci, was released to the atmosphere. Radiocesium concentration andtransport mechanisms for atmospheric, surface water, and groundwater have _en extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SP, EL). The overall ngliological impactof SRS releases on the offsite maximum individual can be characterizedby total dosesof 0.33 nuem (atmospheric)and 60 mrem (liquid), compared with a dose of 12,960 nare_ fromtmn-SRSsouree_ duringthe same period of time. Isotope _r_Cs releases haveresultedin a negligiblerisk to the environment and the population it supports.

Cesium in the Sa'_,annahRiver Site Environment is published as a part of the Radiological Assessment Program (RAP). lt is the fourth in a series of eight documents on individual radioisotopes released to the environment as aresult of Savannah River Site (SRS) operations. The earlier documents describe the environmental cortsequences of tritium, iodine, and uranium. Documents on plutonium,strontium, carbon, and technetium will be published in the future. These are dynamic documents andcurrent plans call for revising and updating each one on a two-year schedule. Radiocesium exists in the environment as aresult of above-ground nuclear weapons tests, the Chemobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operationof industrial, medical, andeducational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of _TCswas released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantifies were released from the fuel reprocessing operations. About 1400Ciof lrPCswas released to seepagebasins where it was tightly boundby clay in the soil. A much smallerquantity, about four Ci, was released to the atmosphere. Radiocesium concentration andtransport mechanisms for atmospheric, surface water, and groundwater have _en extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SP, EL). The overall ngliological impactof SRS releases on the offsite maximum individual can be characterizedby total dosesof 0.33 nuem (atmospheric)and 60 mrem (liquid), compared with a dose of 12,960 nare_ fromtmn-SRSsouree_ duringthe same period of time. Isotope _r_Cs releases haveresultedin a negligiblerisk to the environment and the population it supports.

A detailed palaeomagnetic investigation has been made of the Mull (Scotland) regional dyke swarm. 165 dykes were sampled in a 7-km section across the swarm from Quinish to Ardmore in northern Mull. A major question arising from the results of the investigation is whether the cleaned NRM directions for the dykes are equivalent to the original cooling TRM directions. The question arises since evidence from several lines shows that the dykes have experienced considerable hydrothermal alteration, with reheating temperatures averaging 200°C and major changes in the iron titanium oxides responsible for the NRM. Surprisingly, the answer appears to be that original cooling TRM directions are probably still well represented by cleaned NRM directions.Notwithstanding the large number of palaeomagnetic directions obtained from the dykes, no simple picture of the Palaeogene geomagnetic field emerges. Thus, continental drift cannot be estimated from the data. The explanation for the distribution of directions appears to rest between either a short time of activity for the whole British Tertiary igneous province with non-representative sampling by the activity in individual areas, or the existence of relatively long periods of non-centred axial dipole behaviour for the geomagnetic field during the Palaeogene.