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z. REPORT ON DISPOSAL OF RADIOACTIVE WASTE ON LAND . _ . . . . The Committee on Waste Disposal was set up at the request of the Atomic Energy Commission to study the possibilities of dispos- ~g of raclioactive waste ~naterials on land arch to indicate what re- search was needed to determine feasibility . In September 1955 a conference was held at Princeton which inclucled repro sentative s of AEC, members of the Department of Sanitary Engineering of Johns Hopkins, representatives of the U. S. Geological Survey, Poultry and many individual scientists compe- tent ~ relevant fields. Informed opinions were rendered at the con- ference on the questions asked by ARC 80 the present general report can be a brief summary of the maw conclusions. The factual data resulting from the conference are included In this report as ap- pendices . As ~ outgrowth of the conferences (the preliminary ones at Johns Hopkins add the comprehensive one at Princeton) numerous reports have been made by *ndiv~cinals and committees dealing with the waste problem. In particular the summary by Drs. Hatch and Lieberman for the NAS-N~C "Study Group on Dispersal and Disposal of Radioactive Wastes" covers in adequate form much of what might have been included in a report of the present committee. ....... . .. ... . The Conference and the subsequent studies of the ~mmit-tee macie it obvious that there is no specific answer to such a question as "How sham we dispose of radioactive waste?" On the other hank, given a specific geographic site and specific the of waste, a spe- ~ . . . . . . _ _ ~ _ ~ ~ , , cific answer as to feasibility and cost of waste disposal becomes pos- sible. It is then a chemical engine erring, geological :=d economic investigation with definite parameters for which a OCR for page 2
3. Unlike the disposal of any ocher type of waste, the hazard related to radioactive waste is so- great that no element of doubt should be allowed to exist regarding safety. Stringent rules must be set up ~d a system of inspection Id monitoring instituted. Safe disposal means that the waste shall not come ~ contact with any liv- ing thing . C ons ide rin7g half -live s of the is otope 6 in waste this me an 6 for 600 years if Csl3 and Sr90 are present or for about one-tenth as many years if these two isotopes are removed. The Committee has heard a number of descriptions of the waste disposal operations at Hn"ford ~d Oak Ridge and several com- mit;tee members have visited the Oak Ridge Installation. Some ques- tions exact at this time ~ the minds of most members concerning the long-term safety of waste disposal as practiced on these sites if con- t~ued for the indefinite future. A great cleat of work has beer done at each of them by competent men, but it is not possible to say ex- actly what may happen to the waste and how its component elements may clisperse. The above statements should ~ no sense be regarded as criticism of officials responsible for the operation of Mere ~stal- lations. They were constructed during We exigencies of a war so that punt location wad respect to waste disposal could not be an o~rer-riding consideration. They are ~ isolated localities far from population centers so that the hazard has been ~runimized ~ this re- spect, and ~ acidition, cont~n~g control is being m~t~ed by the operators . . The Committee is convinced that radioactive waste can be disposed of safely ~ a variety of ways ~d at a large number of sites ~ the United States. It may require Bearers years of research and pilot testing before the first such disposal system can be put into operation. Until such time storage ~ taziks win be required for waste . The cost of safe waste disposal win probably be relatively high until a great deal of research has been Forte and experience gamed. Transportation costs have to be added to over-= disposal costs. For this reason site selection for any chemical processing plant where large quantities of highly radioactive waste win be pro- duced, must be based on availability of a disposal area W~thiz~ eco- nomic transportation distance . Economic bed once wan e=st between length of cooling time ~ t~ks at We site of waste production vat cost of transportation ~ shielded carriers -- the thickness of the shielding required being dependent on cooling time. A ~ ~ AN ~ _,

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~ - q 4. It ~11 not be possible to dispose safely of large quantities of high-level waste in mu ,r large sections of the country. This cir- cumsta~ce may dictate that it will not be economically feasible to place those types of power reactors or other nuclear facilities which produce liquid wastes ~ large quantity in such unfavorable sections _ ~ , ~ . ~~ - ~ ~ . ~ ~ ~ ~ of the country. We have on several occasion" seen ashen SUCh ques- t~on" as "Where can waste be disposed of within 25 miles of Tarry- +~,__ A.. =~_t'~ 1' - ~~ _.. ~bl_~+ ~;~1~,; ~ +~+ Or Its - ~~+ TV WE ~ A~= W 1 Vet Be; 1 &~= CLOT - ~4 C~O ~ - - ~ - ~~,, To - Arc - " Ice - .~ TV be disposed of safely anywhere near this site. We stress that the necessary geologic investigation ot any proposed site must be com- pleted and the decision as to a safe disposal mews established before authorization for construction is given. Unfortunately such an inves- tigation might take several years awl cause embarras~;ing delays in the issuing of permits for construction. This situation can only tee handled by starting investigation now of a large number of potential future sites as well as the complementary laboratory investigations of disposal methods. With the example of Tarrytown mentioned above it might be re- marked~chat the probability of inkling a safe ultimate disposal means at the Savannah River plant appears equally gloomy. This only serves to emphasize the need for consideration of dispo~;al before a site is chosen. . - A discussion of the various possibilities for waste disposal mav ~ _ , be found in Appendices C any D, the Reports of the Committees for "deep" and "shallow" disposal, respectively. The most promising method of disposal of high level waste at the present time seems to be ~ salt deposits (see Appendix F by Heroy). The great aci~rantage here is that no water can pass through salt. Fractures areself-sealing. Abandoned saltminesorca~ties especially meek to hold waste are, in essence, long-enduring tanks. The possibility of making cavities in salt by pumping in water and removing brine is not favored (except for waste In solid form) unless the size and shape of such a cavity can be accurately controlled. The major element of potential risk In disposal in salt is that the cavity ~ collapse, structurally, in time. Salt is a weak material and will flow. Hence research is needed on size and shape of openings which can be relied upon to be structuraUv stable. The cavities should be . , - ~ ~ ~ . .. . . . ~ . ~ ^. . _ i, at relatively 8h~10W repro lo aVOlO nlgn CO=lUlNg pressures . Halt beds and mines are abundantly available along the south side of the Great Lakes from New York to Michigar, and also ~ the form of salt domes along much of the Grief Coast. Smaller sat deposits are

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available at a Abet of other sites . The second most promising method seems to be ~ forming a silicate brick or slag which would hold Al elements of the waste in virtually *a soluble blocks. These could be storecl ~ sheds on the surface ~ arid areas or ~ dry mines. Separation of the Ce Ad Sr isotopes from the waste and their storage id sma]1 packages or surface ten ke would of course greatly simplify He gener=1 problem of waste disposal. Research on the feasibility of such separatist= should be pushed. Foamy, die - By of waste ~ porous media such as sandstones at comparatively great depth may eventually be possible. Unlike oil, the waste worm be denser than Me normal saline water contained such beds provided We heat generated by radioactive decay after emplacomcut is not a - dicier to reverse the density relationship. Instead of conce~tratizlg ~ and berg immobilized ~ tops of ~ticlines it would sink to floors of syncli-e''. Deep Yes with closure worm be preferred as disposal structurce inasmuch as they Louis largely "nmob4ii~e He Ate if it was not aDowed to become too hot. The great hiCatty ~~ Did potential memos is At the character of Be waste fond would have to be drasticaDy caged to permit in to disperse in the porous medium without clogging the pore space.l Acid alm~um nitrate waste would almost certainly form a gel-like ~bst~ce if pumped into a Atone. Extraction of the radioactive el~nents from He much larger bum of aluminum Disrate appears at present to be a prol~biti~rely expensive process. If processes were charged to produce waste without Sib ~~avorablc character deep disposal would become much more reasonable. The posaibi~y that great ~;1ution of aluminum nitrate waste fluid might Senate pore space. Clogging should be investigated though it does loot seem likely At He problem ~ be solved in his way. Folded rocks containing- porow beds ~ which suitable strnct~ros could be located are widely dist~b~ed ~ the United Stattes. . 5 Thecore remarks indicate the most promising avenues on which research shoed be pressed. Besides these, it is necessary to train a number of geologists In the attributes of the wastes ~d Me posaSble solution of He proble~ne of their disposal. Geoic~gical ~n- ~restigation of a large number of potential sites for proceas~g plants i/ Edwin Roedder (USGS) (}956) Disposal of high aluzz~num radioac- tive waste solutions by Ejection into aquifers.

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- ~ - 6. or reactors producing liquid waste should be undertaken without delay. The question should not be phrasecI: "How can we dispose of waste at X sited" but should be: "Can or cannot waste be disposed of at X site?" The possibility of the negative answer should always be con- sidered. SPECIFIC RECOMMENDATIONS ON DISPOSAL 1 . Storage In tank'; is at present the safe at and pos sibly the most economical memo ct of costing waste. 2. Disposal In salt is the most promising method for the near future. Research should be pushed immediately on the structural problem of stability vet size of cavities at a given depth) on the thermal problem - getting rid of the heat or keeping it flown to ac- ceptable levels - and on the economics of such disposal. (Appendix F by Heroy) 3. Next most promising seems to be stabilization of the waste in a slag or ceramic mete real forming a relatively insoluble product. This could be placed ~ dry mines, surface sheds or large cavities salt. 4. Disposal of waste In porous beds ~nterstratified with im- ~ . . permeable beds ~ a synching structure is a possibility for the more distant future. This is of particular interest for di8poB~ of Me 1~ .,~19~_~ - ~` .~~ ~~ +~ ~~ ~~ ;~ +~ ^~-~ ^~^ YE ID Vim DIG "~ ~~ ~~_~ ~ - ~~ ^~ ~ ~ Very difficult c' , and complex problems have to be solved before it wiD become feasi- ble. The reaction of Ike waste Ah connate waters or constituents of the rocks soluble ~ Me waste solution win have to be studied. The composition of the rocks and We connate waters are both variable as win be the composition of the waste solutions so that an almost in- finite variety of circ~natances result. ~ general acid aluminous waste would almost cert=$dy tend to form precipitates which would clog pore spaces. The problem would have to be colored first for a given bed at a given site for a given waste solution at a given dilution. 5. The removal of Csi37 and Sr90 from the waste would make . . i8poB~ somewhat easier for Me waste free of these isotopes but does not change q~itati~rely the- recommendations made In the report. 6. ~ the complex relations between (a) storage time of waste for cooling, {b) transportation cost In shielcled carriers and (c) clis- tance to disposal site, the last of these factors must be considered

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before location of any plant producing large quantities of waste ~ remembering that there are large sectors of the country where dis pearl is not pos Bible . 7 . Continuing disposal of certain /large volume/ lo or level waste ~ the vado''e water zone, above the water table, is of limited application and probably involves unacceptable long term risks. GENERAL RECOMMENDATIONS ON COROLLARY PROBLEMS 1. The movement of gross quantities of fluids through porous media is reasonably weld understood by hydrologists and geologists but whether this is accomplished by forward movement of the whole fluid mass at low velocity or whether the transfer is accomplished by rapid flow in "ribbons", is not known. In deep disposal of waste ~ porous media it win In many cases be essential to know which of these conditions erupts. This will be a difficult problem to solve. 2. The eclucation of a considerable numb en of geologists en cl hydrologists ~ the characteristics of radioactive wastes and its disposal problems is going to be necessary. . . .