T T m " " - MAHTIN M A owome® I e ovo serses 4 Chemlstry Transuranlc 3 445k 0352724 Y Elements 74 - N - ¥ ] %‘ ! ;;;*‘*;,g‘- i W 2L s o S e ™, sy 5 RS & fé' syt FLUORIDE m&%&&g‘fl%fi?fl R. E. LEUZE CENTRAL BESLANRCH Lilfany DOCUMENT COULLECTION LIBRARY LOAN COPY DO NOT TRANSFER TO ANOTHER PERSON If you wish someone slse lo sea this document, send in name with document and the hLibrary will arrange a loan. OAK h?ifi?-é:' NATIONAL l.noutmv Lo nnmwfip BY- CARBIDE AND: CARBON CHEMICALS DIVISIONR UN'UN flflfl.lbt AND UAR-UN BQRPDRATIDN I S m Ml‘l‘ amu sox » - m mun. uunuu: L Report Fumber: ORNL-980 This decument comsists of 36 pages. . Copy __z of 112 , Series A . Contract Ho. W-ThO5, eug 26 CHEMICAL TECHNOLOZY DIVISION LABORATORY SECTION DRY FLUORIDE PROCESS STATUS REPORT R. E. Isuze Experimental work by: H. B. Graham Ces P. Johnston A. B. Green R. E. Leuze CLASSIFICATION ancm To: D"_E“g!:_,,mm_-_ S BY AUTHOLRFTY OF aovawnie _fi./j S D —— fi-&&mm _..7 As 2 DATE ISSUED Mak 27 1859 OAK RIDGE NATITONAL ILABORATORY Operated by CARBIDE AND CARBON CHEMICAILS COMPANY A Divislon of Union Carbide and Carbon Corporaticn Pogt Offlee Box P Osk Ridge, Tennesses MARTIN MARIETTA ENEAGY 5YSTEMS LB TR 3 445k D352724 y — - 1.0 2.0 3.0 5.0 590 6.0 T0 8,0 9.0 Contents Abstract Introduction Summary Preparation of UFg from Uranium Metal k,1 Fluorination E;luipment and Procedure k.2 Fluorination Results Adsorption of Fission Products and Plutonium 5.1 Adsorption on Copper 5.2 Adsorption on Alundum Filtration of Uranium Hexafluoride 6.1 Filtration Equipment and Procsdure 6.2 Filltration Results and Discussion Regublimation of Uranium Hexafluoride T-1 Sublimation Equipment and Procedure 7.2 Resublimation Results and Discussion Overall Results Recormendationg 9.1 Preparation of Uranium Hexafluoride 9.2 Adsorption Techniques 9.3 Digtillation Studies 9.4 Phase Diagram ORNL-~ 980 nge No. O O 1 o W 10 13 1k 1k 15 16 16 17 17 19 19 19 19 20 - 4 ceIL- 980 Conterrfi_é .(@ontinuea) Page No. 9.5 Filtration : 20 9,6 Equipment Development 20 10.0 Bibliography 2l Tables 1. Remowval of Plutopnium and Fission Products from Uranium 22 by Fluorination 2, Removal of Plutonium and Fission Products from Gaseous 2l TF¢ by Adsorption on Copper 3. Removal of Plutonium and Fission Products from Gaseous 25 UFg by Adsorption on Alundum 4. Removal of Plutonium and Fission Products from Gaseous 26 Ufi'é by Filtration 5o Removal of Plutonium and Fission Products from UFg by 27 Batch Sublimation 6. Overall Results for Dry Procesgsing , 28 7. Purity of UFg after Dry Processing 30 Filgures 1. Schematie Diegram Por Dry Fluoride Experiments 32 2, Fluorinator .\ssembly 33 3, Copper Adsorpticm Trap 34 k, Alundum Adsorpticmn Bed 35 5, Filtration Assembly | 36 iy =5- | ORML- 960 il MR T Ml Urenium hexafluoride was prepared by the direet combination of irradisted wranium metal wilth elemental fluorine and subsequently de- contaminated by adsorption, filtration, and sublimation on a laboratory geale, g -6~ ORNL- 980 2.0 Introduction Early in project history, a dry fluorinmation method(l’é) vas considered for separating wranium from fission products, plutonium, and other trans- uranic elements. This method consisted of converting uranium to the hexa- fluoride and effecting the separation by distillation; however, it was necegsary to place the major effort on other processes which would require less development time. It now seems desireble to make a thorough evaluation of fluorination methods since they offer the following advantages over the present wet processes: (1) smaller equipment with few or no moving parts is required; (2) the waste volume is minimized since fluorine is the only major chemical used; (3) fission products are obtained in a concentrated form making them easily recoverable; (4) the uranium is recovered as UFg which requires a small storage volume and which is the feed material for the isotopic separation plants; (5) it may be possibdle to process short cooled material, thus reducing the uranium Inventory requirements. There are two outstanding limitations to this type process: (1) the high cost of fluori- nating agents and (2) the danger involved in handling volatile radiocactive materials. Before a dry fluorination process for decontaminating wranium and plu- tonium may be seriously considered; the actual separations obtainable mmst be demonstrated. Fluorination, copper adsorption, Alumdum adsorption, f1l- tration, and resublimation were Investligated as methods of seperating uranium from plutonium and fission productz. These serve as preliminary studies upon which a future progrem can be based. . _ -1- ORNL- 980 3.0 Summary The plutonium content of UFg prepared from uranium metal irradiated 335 days in the CORNL pile and cooled 30 months was reduced to<l Pu « ct/m/mg U by passing the UFg through a bed of Alundum, and then either filtering or resubliming the product. Fission product beta activity in the same material was reduced to 1 - 50 cts/m/mg U by filtering and re- subliming the UFg. | Alundum adsorption was the most effective means of removing plutonium from UF;, giving separation factors of 13-96 and rendering that plutonium passing through the bed non-volatile so it could be removed by filtration or regublimation. Plutonium separation factors for the other steps were: fluorination; 1.1 - 2.4; copper adsorption, 1.1 - Th; filtratién not pre- ceded by Alundum adsorption, 1.4 - 4; and resublimation not preceded by Alundum adsorption, 1.3 - 290 Filtration of UFg through barrier backing at 70°C was the most effective method of removing the fission products and gave a beta decontamination factor of 103. Because of the larger amount of ruthenium passing through the filter at 230°¢, fihe fission product beta decontamination factor was only 300. Filtration, however, has two limitatioms: (1) it does not remove volatile fission product fluorides, and (2) the barrier backing camnot be satisfactorily dried after washing it free of plutonium and fission products. Other beta decontamination factors were: resublimation, 12-330; fluorination, L ~8- ORNL~ 980 mmary {continued) 2-133 Alundum adecrptiom, l.k; =and copper adsorption, 1.1. Uranimm losses were 1 - 3% for Alundum adscrption, 1 - 24% for resubli-; wation, end 0.3% for fluorination, copper adsorption, and £iltration. The lossss rin Alundum and resublimation may be reduced by improved operating techniques, The progrem proposed for the immediste future Includes (1) a survey of other methods of preparing UFg from uranium metal, (2) a study of adsorption technigues for ramoving plubonium from UFg, avd (3) an investigation of fracblonal distillation for remeoving the volatile fissiom product fluorides from UFg. k.0 Preparstion of UFg from Ursnium Metal Uranium wetal may be converted Yo uranium hexstflucride by several dif- ferent methods. The umetsl may be reacted with hydrogen to glve uranium hydride which cam thea be reacted with szhydrous HF to glve UFLB )o This UF), is then reacted with flucrine to produce UFg. Uranium metel reacts with the interhelogens, C1F3 arnd BrF3, to give vranium hexafluorlde. Uranium may alse be combined directly with elemental fluorine to produce Ung(e) o Thege various methods have certaln advantages and dlsadvantages which will not be discussed here. The direct combination of fluorine with uranium was used to produce UFg in these laboratory experi- ments because of its convenience and not because it was felt to be superior to the other procedures. SRy -9- ORNL- 980 4.1 Fluorination Equipment and Procedure Fluorine was transferred from cylinders through a bed of sodium fluoride to|remove HF and then through s monel, Hoke needle valve and a glass rotameter into the fluorinstor (Figure 1). The fluorinator was a cup made from a 2 inch piece of 1-1/2 inch nickel +tubing (Figure 2). The cup was placed in a stand fabricated from a stainless steel flange and stainless steel pipe. The fluorinator top was a disc of nickel sheet with a fluorine inlet and a UFg outlet. This assembly was sealed between stain- less steel flanges using an aluminum wire gasket. A conical electric heater wag used to bring the reactor and uranium metal up to temperature. The alwminum jacket was removed mechanically from a 40 - 250 gram piece of slug irradiated in the ORNL pile. The oxide film was removed in nitric acid and then the wranium was thoroughly dried and placed in the fluorinator. After evacuating the equipment, the temperature was raised to 300-350°C and 20 ml/min of fluorine was fed to the reactor. A sharp rise in temperature gave evidence that the reaction had staxrted. The ex- ternal heat was then removed, and the fluorine flowrate was increased to about 250 ml/min. The temperature rose to about 400°C and gradually dropped to 300°C. When fluorination wes nearly complete; a rise in temperature of 150-200°C in a few seconds indicated that only a small amount of unreacted " metal remained. After the reaction subsided, external heat was applied to raise the temperature to 500°C for 30 minutes before stopping the fluorine flow. This procedure removed the last traces of metal and Tower fluorides. e, wnNNg -10- ORNL- 980 Fluorination Equipment and Procedure (continued) The UFg produced was passed through adsorbers and/or filters to effect decontamination and finally condensed in traps cooled in dry ice and tri- chlorethylene (Figure 1). Gases passing through the cold trap were sent to a soda lime trap and vented to the hood exhaust. After filuorination was complete, the equipment was evacuated and swept free of fluorine by means of nitrogen. The fluorinator was dissolved in nitric acid, and an aliquot of this solttion was weed for analyses. 4.2 Fluorination Results The results obtained for the fluorination of ursnium metal irradi- ated 335 days and cooled 30 months are presented in Table 1. From & to 20% of the plutonium remained in the reactor, while only 0.0006 - 0.08% of the uranium remained behind. Gross B, Gross ¥, Ru B, TRER, CsB, and Srp decon- tamination factors were all within the range of 2 - 13. The higher uranium losses in experiments 1 and 14 were a result of in- complete fluorination due to too short a heating period in a fluorine atmos- phere after the reaction had subsided. The high values for the fission pro- duct decontaminétion factors and plutonium.hold up in Experiments 1, 2, and 3 resulted from increased reactor size and the uneven temperatures in the reactors. Since the only fission products present form non-volatile or only slightly volatile fluorides, the main reason for the low and inconsistant decontamination factors was solid entrainment in the gaseous UF5. TRORE— Gl -11- ORNL- 980 Fluorination Results (continued) In experiments 7, 14, 16, and 17, the reaction was started by first filling the equipment with nitrogen instead of evacuating it. As a result, the plutonium remaining in the reactor was 30-40% instead of 4 - 20%. The reason for this difference 1s not understood; however, a test (Exp. 18) was made to determine plutonium hold up when the equipment was first evacuated and the uranium then fluorimated with a mixture of 55% nitrogen and 45% fluorine. The plutonium remaining in the reactor in this case was only 10%. Ag yet no method is known for keeping all the plutonium in the reactor nor for removing it all by volatilization when fluorine gas is the fluorinating agent. The direct fluorination was carried out at a rate of about 20 grams of uranium converted per hour. This rate was controlled quite easily by regu- lating the fluorine flowrate. There was little or no reaction noted between uranium metal and fluorine at temperatures helow 300°C, and additional heat was needed at the end of the reaction to fluorinate the last traces of uranium metal and intermediate fluorides to UF6° 5.0 Adsorption of Fission Products and Plutonium Since PuFg has almost the same vapor pressure as UFéh), its separation from uranium by fractiomal distillation would be difficult and some other method; such as adsorption; for effecting the separation would prove to be e ———— w—— -12- ORNL- 980 Adgorption of Fission Products and Plutonium (continued) of sconsidersble value. Previous work showed that plutonium hexafluoride is less stable than UFg since the plutonium plated out on copper connecting lines in the experimental apparatus(5). Adsorption on copper and Alundum were tested and copper was found to be partially effective and Alundum com- pletely satisfactory for removing plutonium from UFg. Neither the copper nor the Alundum removed enough of the Gross B activity from the UF6 to be of value for a deconmbamination procedure. Graphite and activated c¢alcium sulfate were found to react with UFg at 100°C and so were mot tested further. Sodium fluoride and UFg form an inter- molecular compound which decomposes to give fluorine when heated. Since UFg camniot be remcved frem this compound by sublimation, sodium fluoride was not soneidered as an adsorbing medium to remove the plubtonium. 5.1 Adsorption on Copper Three types of copper traps were used to adsorb plutonium: (1) a coil of 1/4 inch tubing 3 feet long, (2) a "U" tube 9 inches high made from 1-1/8 inch dismeter tubing and packed with copper turnings, (3) cylin- ders 2 inches in diameter and from 3 to 15 inches long (Figure 3). The gtream of gaseous uranium hexafluoride from the reactor was passed through these vessels which were heated to 70-80°C in & water bath. After the ex- periments were completed,; the traps were washed with diluté nitric acid to removed the plutonium, uranium, and fission products. o S -13- ORMNL- 980 Adsorption on Copper (comtinued) The three feet of copper tubing removed 27% of the plutonium while the trap packed with copper turnings removed 70% of the plutonium, In the experiments using the 2 iuch diameter copper traps, the amount of plutonium held up was proportiomal to the length of the traps (Teble 2).. This increase of adsorption may be due to the increase of surface area, increase of comntact time, or both. The plutonium hold up for the 3-1/h inch trap was 21%, for the 7-1/2 inch trsp was 57%, for the 9 inch trap was 98.7%, and for the 15 inch trap was 92.2%. The high value for the 9 inch trap is not explained. The results indicate that thé last trace of plutonium may be difficult to remove by mears of adsorption on copper. The fission product decontamination factor over these traps was negli- ‘gible (gbout 1.1). The uranium hold up waa small (£0.3%) except when the copper adsorption was preceded by condensation and resublimation as in Experiment 12. This high loss of 8% may either be due to reduction of UFg during the first condensation or to an inadequate sweep out of the equipment after resublimation. 5.2 Adsorption on Alundum Chips from Alundum crucibles were placed in a nickel tube 1 inch in diameter and 9 inches long (Figure 4). The bed was heated to 100°C in a tube furnace, and the gaseous UFg stream from the fluorinator was passed through the Alundum. For analytical purposes the plutonium, wanium, and fission products were removed from the Alundum by elution with 30% nitric acid. e ———— — -1l - ORNL- 980 Adsorption on Alundum (continued) The Alundum bed removed 92-99% of the plutonium (Table 3). The plu- tonium passing through was thought to be non-volatile since it could be easily removed by filtration (Experiment 22, Table 4) or by resublimation of the UFg (Experiments 20 to 21, Table 5). The uranium loss on the Alundum was 1-3%, and the fission product decontamination factors were only about 1.k4. 6.0 Filtration of Uranium Hexafluoride Durlng early experiments a considerable quantity of fission products was carried over from the fluorinator to the cold trap. This suggested that solid particles wers entrained in the gas since all the fission pro- ducts present formed non-volatile or only slightly volatile fluorides. Barrier backing tubes were used as & laboratory tool in determining whefher or not the activity and plutonium carry-over was due to entrainment. 6.1 Filtration Equipment and Procedure A nickel, barrier backing filter tube 1/2 inch in diameter and 5 inches long was fitted with nickel ferrules. One end of the tube was closed and the other end was flanged. This assembly was sealed into a nickel tube (1"D x 8") by the use of heavy flanges and a double gasket arrangement (Figure 5). A thermocouple well extended through the end plate flange %o the center of the barrier backing tube. The inlet and outlet for the f£il- ter consisted of 1/4 inch brass tube fittings silver soldered into the ends of the case. T ] -15- - CRNL- 980 Filtration Equipment and Procedure (continued) Uranium hexafluoride was passed through the barrier backing at 70 - 225°¢, After filtration was complete, the barrier backing and ferrules were dissolved in concentrated nitric acid, and the case was washed with dillute nitric acid. Theses solubions were analyzed for gross B, plutonium, and uranium. 6.2 Filtration Results and Discussion When the ursnium hexafiuoride came directly from the fluorinator, the plutonium hold up on the filter was 30 - 75% and was not a function of temperature in the range of T0°C to 230°C (Teble 4). Omly 0.01 - 0.15% of the uranium remained on the filter. The high value of 3.7% in Experiment 14 may have been caused by incomplete nitrogen sweeps of the equipment after the reaction was completed. The gross P decontamination factor was 103 when the filter was operated at 70°C and 300 When the temperature vas 220 - 240°¢. The only individual fission product decontamination factor tha;h wag sub- gtantially affected by temperature was that for ruthenium. At 70°C, the Rug decontamination factor was 200-500, and at 225°C it was only 15. In general, the decontamination factors for Csp, Sr3, and TRER were slightly greater than 103, When filtration was preceded by resublimation, the filtration showed little improvement in decontamination since the activity was too low for accurate analysis (Exp. 19). SlaRE -16- ORNL-980 Filtration Results and Discussion (continued) When the filter was used after an Alundum adsorber (Experiment 22), <1 Pu o ct/m/mg U passed through the filter and<T.0l%f the uranium stayed on the filter. The fission product decontamination factors were of the same order as for filtration of uranium hexafluoride coming directly from the fluorinator. Since no way is known to removed plutonium, uranium, and fission pro- ducts from the bar:ier backing except by washing,; it is recommended that fil- tration of this type be used only as a laboratory tool and not be considered for large scale operation. After washing barrier backing, it is very dif- ficult to dry it thoroughly enough to pass UFg and F, through it again. T.-0 Resublimation of Uranium Hexafluoride Simple batch sublimations were made to determine their effectiveness in further decontaminating UFg from fission products and plutonium. 7.1 Subliimation Equipment and Preocedure Uranium hexafluoride was condensed in copper traps of various sizes, the trap most used being a cylinder 3 inches in diameter and 12 inches high. To carry ofit a resublimation; the trap containing uwranium hexafluoride was Placed in a water bath and heated to 90°C. The uranium.hexafluoridglwas volatilized and passed through a copper conmmecting line to a similar trap placed in a bath of dry ice-trichloroethylene. A reasonable length of time was allowed for the sublimstion to take place, since there was no convenient method of determining when it was complete. No nitrogen or fluorine sweeps ey SRy -17- ORNL- 980 were made to remove the last traces of UFS. T.2 Resublimation Results and Discussion The results for batch resublimation varied considerably for two reasons: (1) the resublimation was crude and often incomplete, and (2) the previous treatment of the uranium hexafluoride varied widely. The only fission products present form non-volatile fluorides which must have been carried into the cold trap by entrainment. The resublimation should serve primarily to remove the uranium hexafluoride gas from these solids. Sinece the distillations were crude, the amount of solid entrain- ment varied and gave s wide range of decontamination faetors. Gross B decontamination factors were 12-330 (Table 5). For resublimation preceded by filtration, the amount of activity present was so small that the gross B decontaminstion factors could not be determined. Plutonium decontamination factors over the resublimation step were probably dependent upon both the entraimment phenomenon agd the adsorption of the volatile plutonium on the copper walls., Resublimation removed 80- 100% of the plutonium. Uranium losses varied widely due to incomplete sublimation and sweep out of the equipment. 8.0 Overall Results Fluorination, copper adsorption, Alundum asdsorption, filtration, and resublimation procedures were combined in various ways to study the separation SRR ] -18- ORNL-980 Overall Results (continued) of plutonium sund fission products from uranium metal irradiated 335 days in the ORNL pile and cocled 30 months. The overall procedure and results for various experiments are given in Table 6. Purities of the uranium hexsfluoride products are given in Table 7. The most effective removal of fission products was made in the ex- periments involving a filtration step. The overall gross 3 decontamination factors varied from 3 x 103 to greater than 10‘1'F and the products contained 1 - 50 B cts/m/mg U. Experiments containing a resublimation but no fil- tration were less effective in removing fission products. Gross B decon- tamination factors were 230 to 1.4 x 103 with a corresponding higher activi- ty in the product. The one experiment (No. 1) which used only fluorination and copper adsorption gave a gross B decontaminetion factor of only 12. The most effective and only satlsfactory removal of plutonium was made in experiments using Alundum adsorption. In these experiments (Nos. 20, 21, 22) the plutonium decontemination factors were 6 x 103 4o 6 x 10* and the uranium product cowtained< 0.5 plutonium ct/m/mg U. In all the other experiments,plutonium decontamination varied widely; however, large copper adsorbing surfaces tended to increase the decontamination factors. Uranium losses for all the experiments were quite high. These losses were explained under the variocus sections in this report dealing with the individual operatioms. It may not be possible to reduce the uranium loss of 1 - 3% on the Alundum adsorber; however, by improved operating technigues the other losses can be reduced to <0.1%. i, ey -19- ORNL-~ 980 vt —le 3 9.0 Recommendations The results of the experiments presented in this report serve primarily a8 a gulde to further investigations. There are many problems remaining to be solved and the following recommendationsg deal only with those which should te studied in the immediste future. 9.1 Preparation of Uranium Hexafluoride A thorough investigation of various methods of converting uranium metal to UFg 1s peeded. From this study should come the optimum procedure from the view point of safety, ease of operation, and economics. 9.2 Adsorptlon Techuiques A more complete survey of adsorbing media for removing plutonium and of elution methods is needed. Design information should be obtained for the most promising adsorbers. 9.3 Distillation Studies A program to determine the relative volatilities of various fission product fluorides is now in progress. Determination of the optimum distil- lation methods, and testing on a laboratory scale should be carried out. SRR -20- ORNL- 980 9.4 TPhase Diagram Solubilities of the fission product fluorides in uranium hexa- fluoride should be obtained. Phase diagrams involving BfiF3, C1F3, and HF will also be needed if these materials are to be used in the fluoride process. 9.5 Filtration At present, filtration seems to be valuable only as a laboratory tool. Filtration in large scale operations is not desirable due to dif- ficulties of washing the filter free of plutonium and fission products and then drying so it can be reused. At this time no further work need be done on this procedure. 9.6 Equipment Development Special equipment and samplers are needed to study all of the previously mentioned problems. Development and testing of this equipment can best be carried out along with the investigations for which the‘equtp; ment is needed. Rl ~-21- ORNL- 980 10 o O BibliQE E Lh 2 1. 20 Anderson, H. L., and Brown, H. S., Report CN-362, Liquid UF Plant for the Production of Element 94k, November 27, 10L2. Barry, L. A., Montillon, G. H., and Van Winkle, R., Report K-548, Fluorination of Uranium Pile Slugs with Elemental Fluorine, Carbide and Carbon Chemicalg Corporation, K-25, December 30, 1949, Bernhardt, H. A., Gustison, R. A., Kirslis, 5. S., and Wendolkowski, W. S., Report K-345, Hydrofluorination of Massive Uranium Metal to Uranium Tetrafluoride, K-25 Laboratory Division, February 1, 1949. Florin, A., Dry Fluoride Meeting at Argomne National Laboratory, September 8, 1950. Seaborg; G. T., Williard, J. E., et al, Report CN-696, Chemical Research-Production and Extraction of Plutonium, Metallurgical Laboratory, Report for May 16-31, 1943. Webster, D. S., Report CN-1206 (A-1686), Engineering Studies of Dry Fluoride Process, Clinton Laboratories, January 10, 19hkh. g " -D0. ORNL- 980 Table T | Removal of Plutonium and Figsion Products from Uranium by Fluorination Conditions: (1) Reactor: 1-1/2" OD nickel tube 2 inches deep (2) Uranium metal irradiated 335 daye in the ORNL pile and cooled 30 months. (3) Reaction temperature: 250-6000C (k) Reaction pressure: most experiments started under vacuum and gradually increased to one atmosphere (5) Fluorine flowrate: started at 20 ml/min and increased to >200 ml/min. xperiment| Uranium Feed| % Hold up in Fluorinator Decontamination Factors Number (grams) Uranium Plutonjum| Pu«a | Gross ¥ [Gross 8 | Rup [ Cs B Sr 8 | TRE B 18 35.0 1.698 27 1.5 10 10 7 11 6 10 2P b1 0.300 46 2.0 16 o7 23 21 29 | 27 3P 64.1 0.080 h1 2. | 15 20 15 13 18 | 25 4¢ 16.0 <0.002 12 1.5 7 54 36.1 £0.002 19 2,2 4 6 27.0 <0.060 17 1.2 6 7° 57.5 0.050 33 1.4 7 5 4 5 I 5 8 45.8 0.005 8 1.2 5 5 6 3 b 6 9 50.8 <0.005 5.1 1.2 3 3 I 3 2 3 10 418.0 0.080 8. 1.4 5 T 10 5 L 7 11 41.0 <0.006 5.4 1.4 T T 13 6 5 T 12 72.2 <0.00k T 1.1 L 5 L 3 L 6 13 T5.5 0.01 14 1.6 3 3 6 3 2 3 148 75.8 1.81 Lo 1.9 3 L 7 3 4 5 15 76.0 0.020 19 L.k 4 L 10 3 3 b 16° 2L5,0 0.0006 31 1.5 3 L 6 3 3 L 1gf 50.0 0.070 31 1.9 L 188 37.8 0.03% 10 1.2 3 19 73.3 <0.00k 4,0 1.1 5 T 11 4 5 14 (continued) =23~ i ORNL- 980 Teble I (continued) Experiment ‘Uranium,Feed % Hold up in Fluorinator Decontamination Factors Numbex: (grams) Uranium Tlotonium | PuQ | Gross ¥ |Gross 8 | Rupg [Cs p | Sr B |TRE B 20 21’;07 anog 7 100 '102 }-j' 21 39.9 <0.002 10. 1.3 5 op 48,2 <0.002 15 1.k 5 a A larges reschbor was used 2'D X 67, Temperasture not uniform throughout reactor. A larger reachtor was used 2'D X 12", Temperature not uniform throughtout reactor. s Flaowlnstion carvied out at 20-26" wacuum. 4 TFluoriostlen caxrled out at 4 - 7 psig. e Fluowinabion started with atmosphers of nitrogen in fluorinator. £ Startad under nltrogen sbmosphere. 30%'N2 - T% Fo fluorinating gas. g Staried under vacuwn. 55% Np - 45% Fp fluorinating gas. L. Tnsufficlent heating period after reaction subslded. ORNL=~ 980 e -2k~ Table 2 Removal of Plutonium and Fisslon Products from Gaseous UFg by Adsorption on Copper Conditions: (1) Equipmfib as noted (2) Uranium irradiated 335 days and cooled 30 months (3) Temperature of trap T0-80°C (4) Previous process steps as noted - ' % of Pu % of Original Charge to trap Decontamination Factors Experiment| Previous Process | Copper Trap Held up in Copper | held-up Gr@ssF Gross| Number Stepa Degeription 0 Pa | in trap |Puca ¥ B |[Ru p| Cs BlSr B|TRE B 1 Fluorination 3! of 1/4" 0.2k 19 27 1.k | 1.2 1.2 |2 1.1 |L.1 1.1 tubling ) ! 7 Fluorination 1-1/8"D x 9" 0,30 53 70 L I>5 4 1.5 |& |5 |4 U tube packed 1 ' with Cu twrn- ings ' 8 Fluorination 2" x 3-1/4" £0.01 18 21 1.3 ] 1.03 §1.03 |1.03] 1.03 _]..oh 1.0’4 S Fluorination 2™ x T-1/2" {0.01 ko 57 2 1.2 1.2 1.7 |1l.2 J1.1 }1.2 10 Fluorination 2D x 9" - 71 99 Th 1.2 1l.2 |i.3 |1l.2 j1.2 (1.2 11 Fluorination 2"D x 15" £0.01 66 92 13 1.1 Ji.07 j1.2 | 1.071.07|1.07 12 Fluorinstion 2"p x 15" 8.1 0.07 19 1.1 Pl 1.2 [1.00}1.7 | |1.7 Resublimation Co- T AR—— -0 ORNL-980 Table 3 Removal of Plutonium and Fission Products from Gaseous UFg by Adsorption on Alundum i Conditions: (1) Ca 100 grams of chipped Alundum in a nickel case 1%?D x 9?5 (2) UFg prepared by direct reaction of fluorine and . uranium irradiated 335 days and cooled 30 months (3) Temperaturs of Alundum bed: 95 - 115°C % of Original Charge | % of Pu entering Decontamination Bxperiment | held up in Alundum Alundum which was . Factors Number Uranium Plutoniim held up in the Alundum| Pu Q_ Gross B 20 3.3 T5 92 13 1.3 21 1.3 81 99 96 1.4 22 2.4 T0 98 58 1.3 SEonEN -26- ORNL-980 Table 4 Removal of Plutonium end Fission Products from Gaseous UFg by Filtration Conditionss (1) Filter - nickel barrier backing tube 5/8"0D x 5" in a nickel case i"p x 10" | (2) Uranium irradiated 335 days and cooled 30 months {3) Temperature of filter as noted | (4) Previous process steps as noted - % of Pu i to the Fil- | % of Original Charge|ter held up __D.osonbamins..ou Faghors [Experiment | Previcus Process |Filter Temp. | Held up on Fliter on Gross|Gross| Nunih=r Stepsa og - Pu Filter Pu o ¥ B8 |Ru B] =3 |Sr B|TRE B i3 Fluorination 220-240 0.01 19 29 1.6 | 190 | 310 | 13 | 430 {1200 930 1% 185-203 3.69 27 53 2,1 | »90 | 410 | 17 pe8oo |1800|1400 15 TO=90 0.001 27 38 1.6 | D40 {1100 |220 |2200 |2600|1800 15 65-85 0.009 20 30 1.5 | >80 | 870 |40 {8300 |3800{1200 1y 87-105 0.022 32 61 3 1400 1» | 85-110 0.070 57 75 4 920 L i §9 Fluorination 75-85 0.120 0,85 65 3 >0 | >8 | >2| >k |>80[>100 Regublimation ' — 22 Fluorination 102-110 <0,01 1,15 o7 30 810 Alundum . Adscrption\ SRR ORNL-980 Table 5 Removael of Plutonium snd Fission Products from UFg by Batch Sublimation Conditionss (1) Copper and stainless steel cold traps of various sizes were used. (2) The trap containing UFg wes placed in a water bath at 90°C (3) Previous treatment as noted. (4) Uranium was irradiated335 days in the (RNL pile and cooled 30 months Experiment R % of Original Charge Decontamination Factors Number Previous Process Steps | Held up in Still Pot Pu ¢ Gross 7 |Grosge Bl Ru pB |Csp | Sr 8 |TRE B U Pu 2 Fluorination 0.9 48 19 > 6 L6 5 190 70 140 3 1.6 Lo 100 >25 20 8 27 20 21 i 1.1 68 95 33 5 ,9 43 >2000 330 G 10.8 84 290 320 6 Fiuorination 11.5 0.06 v 1.3 > Resublimetions (2) J‘Z'Ll 7 Fluorination 0.30 5.5 .- > 2 12 > 3 140 0 G0 3 Copper Adsorption 5.9 52 5 >32 250 60 310 [340 280 9 2.3 35 21 >3k 100 5 260 600 310 10 0.08 0.58 5 >55 120 37 140 [50 140 11 2.5 4.5 D 213 80 18 80 70 100 12 Fluorination 16.2 T7 160 w50 70 o 240 60 210 Resublimation : , Copper Adsorption - 13 Fluorination 0.16 43 19 2100 8 18 |[>10 p10 >24 14 Filtration 2.1 2l 30 > 2 >6 20 w6 30 v 39 15 0.15 Wy 90 >2 >2 |22 >3 |»l.3 > 1.k 16 1.k 39 6 >1.1 >21.2]1>21.7 ] >1.5121.k 1> 1.2 19 Fluorination 1.2 86 66 31 100 32 220 ]110 50 50 Fluorination Alundum | 17.8 8.2 1600 ' 0 | 21 Adsorption ' 23.8 0.84 > 50 100 22 Fluorination Alundum 2.9 0.04 >30 > 2 Adsorption Filtration I Saeme -28- ONRL- 980 Table 6 Overall Results for Dry Processing Conditions: (1) Uranium irradiated 335 days in the ORNL pile and cooled 30 months (2) Procedure as listed Uranium |% of Pu in Decontamination Factors Experiment Loss Product \ Gross p[RupB | Ce B | Sr B | TRE B Number _ Prozess Staps(®) % UF4 Py g |seoss v] z10°3 | x10-3] x10-3| x10-3] x10-3 1 Fluorination 1.93 50 2 1L 0.012 | 0.013}) 0.013 | 0.007} 0.01L Copper Adsorphion 2 Fluovination 1.20 Do Tl 36 L0 1.3 0.11 | 4.3 2.0 4.0 3 Resuyhlimation 1.60 Q.41 240 2380 o4l 0.12 | 0.37 | 0.37 | 0.5k b 1.10 0.73 140 .23 | 5 o )} | 1,90 £0.02 1600 1.4 & Flucrinsgtion 20,3 0,023 430 T.0 Resublimstias (2) 7 Fluorination 0.45 15.5 7 »160 o 24 0.015] 3.0 2.2 1.3 8 (‘opper Adsorption 5086 13.7 T »150 1.3 0.35 | 0.90 | 1.4 1.7 G Resublimation 2,31 1.79 60 »L30 » 34 0.037] 0.70 | 1.6 1.1 10 0.93 0.01% T00 >370 1.0 0.50 { 1.0 0.79 | 1.2 11 L 2.52 1.13 90 > 90 50 0.28 | 0.48 | 0.40 | 0,70 iz Fluorination 2h .3 0.290 210 »220 AT 0.037[ 1.2 PpP2.0 ] 2.0 Resublimation | , ) Copper Adsorption _ 13 Fluoriuation | 0.19 2.50 41 >1000 T7-0 1.2 Ppi5. 20. P60a L Filtration 7.60 0.83 120 |>420 }]1i1.0 2.6 Pp50. FR00. 00. 15 Resublimation 0.17 0.49 200 | >330 8.0 L6 behk. P 9.0 PP10s 16 1.43 T.66 13 |>»260 | 3.9 4.8 PB3k pPlo. 6. 17 0.09 20.1 5 6.0 18 0.10 18.7 5 3.0 (continued) ————————————- pmer— -29- ORRL- 980 Table 6 (continued) Uranium |% of Pu in Decontamination Factors Txperiment ( L.oss Product Gross B] Ru B Cs B | Sr B |TRE B Number Process Steps a) % UFg Pu o | Gross ¥ x10“3 x10-3 | x10-3 x10-3 |x10-3 19 Fluorination 1.3 0.46 220 [»2,900 5.5 | 0.70 11. |[»50. Pp8o. Resublimation,Filtration | 20 Fluorination 1 21.1 £0.001 360,000 1.0 21 Alundum Adsorption 25.1 4£0.01 56 ;000 60 Resublimation 22 Fluorination 53 € 0.001 0,000 »10.0 Alundum Adsorption Filtration Resublimation _ (al For mors dabailsd procsdurs, see tables describing each operation. -30- S ORNL- 980 Table 'Z Purity of UFg After Dry Processing Conditions: (1) Uranium irradiated 335 days in the ORNL pile and cooled 30 months (2) Procedure as listed Experiment o ets/m/mg U in Product Nunber Process Steps(a) Pu O ] Gross ¥ Gross 5 Ru B Cs B Sr B TRE B 1 Fluorination 1.1 x 105 9 1.1x10% 410 2.25105 | 2.7x103 | 7 x 103 Copper Adsorption 2 Fluorination 60 £0.9 100 50 6 9 19 3 Resublimation S < 0.3 300 Ll T0 b7 140 L 15 600 5 o < 0.6 90 & Fluorination 6 25 2 Resublimations : T Fluorination 330 < 0.7 500 510 6 T 80 8 Copper Adsorption 300 < 0.8 120 25 21 11 T0 g Resublimation L <1 500 270 30 12 120 10 <3 < 0.3 130 11 27 21 60 11 25 <1l - 290 31 40 39 140 12 Fluorination 10 < 0.5 300 220 15 T 148 Resublimation | ' Copper Adsorption o _ 13 Fluorination 60 < 0.2 w12 < 5 < 2 < 0.9 < 1 14 Filtration 17 < 0.2 < 1 < 2 < 0.5 < 0.1 < 0.3 | | Resublimetdnn ... 1 . .. e L e 15 C | 10 <U.3 <9 <1 C1 w2 w6 16 160 <0.4 15 <l < 0.7 1 12 17 €00 26 18 €00 48 (continued) S -31- ORNL- 980 Table T (continued) Txperiment cts/m/mg U in Product ) Nunber Process Steps(a) Pu O Gresg 7 Gross P Ru B Cs B Sr B i P 19 Fluorination 11 < 0.1 31 14 < 0.4 1.9 1.5 Resublimation Filtration — 20 Fluorination < 0.05 150 21 Alundum Adsorption < 0.5 240 Resublimation 22 Fluorination < 0.03 v 1h Alundum Adsorption Filtration Resublimatlion (%) For more detailed procedure, see tables deseribing each operation. I d 3 e O oo S‘O{m O H o A -32- ORNL-980 Dwg.#10639 FIGURE 1 Vent to' = o 'O @ 3 Hood Soda Lime TT?P“‘~\\ ‘W - , : To ~Alundum Bed, _ - Vacuum Copner Trap | | Pump : or Y . Barrier Backing| Filter Cold Trap—’)’ Fluorinator ' o | 2-7-5/ Z B ©33= FIGURE 2 ORNL-98 - - " t 1 - o FLUCRIHATLR.ASEFmflLY Dwg.# 10640 Fluorine Inle UFg Qutlet Stainlass Stesl Fleage 5" QD x 1.9" 1D Fluorinator Too 1/32" sheet nickel Alunminum Wire Gaslet — - Fluorinator 1 1/2" dia, x 2" long nickel tube Thzrmocouple Steinless Steel 2 Fl?’*fflg‘fi 5" 0D » Conical Electric & A S 1.3" Ip fleater = =/ ;s (AR _ oy L Insulation 1/4" p [ ] e fers E-6-5/ dam eon ORIL- 980 | COFTER ADSORPTICN TRAP Dwg. #10641 l/@" Copper Tubing 2 1/8" Copper Tubing Note - Length varied frem 3" to 15", All joints Silver solderad. 1 1. Z-E-5/ EZ v VSR 4 N ¢ s . ~35- ORNL-~980 Dwg. # 10642 FIGURE 4 ALIWNDIM ADSORETTON PED Aluminum Wire Gaslket 1" dia. Nickel Tube hipred Alundum 1/4" Tube g 1/2" long 1/4" Tute \ Fitting, Mtting, Fress Thermocouple el 1/4" Nickel Tube Note: All materisl Wigke; ~xcept where noted. All joints silver ¢l Cered. 2-8-57 XEw ORNL-980 Dwg.# 10643 FIGURE 5 FILTRATION ASSEMRLY Wickel Flange 4" dia. x1/2" thiclk Aluminum Wire Nickel Thermocouple Gasket Well, 1/4" dis,| x 4"long Nickel Rarrier Backing, 1/2" gdia X 5" lon End drilled & Nickel Flange and taspped for " el x 1/2" thick 1/2" nipe to 1/4" tube fitting. : Nickel Flange | Crilled ¢ Tappad 2 3/8" dia, x 1/32n Nickel Tube for 1/8" pipe to 1/4¢ thick ‘ : 1" dia. x 10" long tube fitting £-& 5/ BEHW,