Attachment #5 FALLOUT OF URANIUM DURING UF6RELE (Taken from KY/L-694, Part 11, 1/ and KY/L-765, Part 2, 3/26/75, T. J. Mayo) Prepared by Martin Marietta Utility Services, Paducah Gaseous Diffusion Plant for the United States Enrichment Corporation under Contract No. USECHQ-93-C- FALLOUT OF URANIUM DURING UF, RELEA (T. J. Mayo, Laboratory) When UF6 is released to the atmosphere, it is ___ UO2F2 and HF by atmospheric moisture. It is ___ a large part of the UO2F2 rapidly fails to the ____tional effects while the HF remains airborne. ___ atmospheric dispersion work is generally ___ (particle diameters less than 20 microns) remain periods of time. The gaseous reaction of UF6 ___ reduces UO2F2 particles of micron or submicron ____ well down in the aerosol range. There is, there about the rapid fallout of UO2F2. There is also HF, with its strong tendency to adsorb on practi___ would attach to the UO2F2 particles and also be should solids fallout occur. In this project, the behavior of the UO2F2 and ___ release of gaseous UF6 to the atmosphere will be _____. CURRENT PROGRESS The method chosen was to release known quantities SF6, sample the atmosphere downwind, and ________ SF6 in the sample. Losses of either U or F _____ variations of the ratios of U and F to SF6 from _____ were released. Loss of either U or F relative _____ be reflected, of course, in the U to F ratio. Approximately 215 grams of UF6 and 14 grams of ___ 5.6-liter Monel bulk with the amounts established bulk was then heated to 230oF to vaporize the ___ the vapor pressure of UF6 is about 76 psia. In actual UF6 pressure was about 50 psia at 230oF supplied by the SF6. The hot bulk was then ____ an insulated box (also heated to 230oF) and then released. The mixture pressure was monitored ___ was no UF6 condensation before release. About ____ or approximately 160 grams of UF6 and 10 grams during each run. The releases were essentially half a minute. Sampling was done with four portable Bendix Med. air samplers. The air was pulled through two K filters to trap the UO2F2 and HF. The sampler and a known fraction (about 14%) trapped in a _____ mination. Occasionally an uncoated filer was coated filters to trap particulates and determine HF. ____________________________. The SF6 analyses were by enromacograhics means us detector. Initially, releases were made in the early _____ was so great that detectable amounts of uranium generally not obtained. Later releases were made in the last 30 minutes before dark. At this time clear and wind speeds low, the atmosphere became lower levels as an inversion builds up. Gravitational be greatest at this time. Results of the runs a table 1. In runs 4, 5, and 6, four samples were taken at each run with the intention of going to greater action of the ratios was such that this approach aging. In runs 7 and 8, the procedure was changing at each of two distances. The results to data have not been entirely unamb_____ observations can be made. There are no indications ____ losses of uranium from the atmosphere at distances. This is based on observation of the clouds which initially as well sa the data in the table. The 7 and 8 suggest a little loss of uranium with di____ ratio gives opposite indications in one case (ru____ lease partly due to sampling problems. For exame seen that more material was found at the greater this release was rather rolling terrain out some roughness caused the cloud to rise over the first them completely before returning to envelope the _______. The only serious problem with the program occurred appears that a sampling and/or analytical problem values. Thus, both the U/SF6 and F/SF6 are unre_____ the U and F data do provide some information rel___tion of HF. To determine whether, in fact, free HF was present runs 6, 7, and 8, one of the samplers had an ex___ front of the K2CO3-created papes. This untreat____ only the UO2F2 with the free HF being caught in runs, 36, 42, and 50% of the fluoride was found. Since one would expect 33% of the fluoride to be that very little of the HF is adsorbed on the ___ ___cles in the atmosphere. The U/SF6 data also gives some information about UO2F2 in the cloud. The untreated filters used microns, and the fact that the expected or high___ found indicates that all the uranium was caught means that the predominant UO2F2 particle data Table 1 FALLOUT of UO2F2 Sampling Sample Total U Distance, Size, Found, Run Sampler vds 4 ug 4 1 125 42 500 2 125 45 580 3 125 49 470 4 125 49 330 Ratio Released 5 1 120 43 49 2 120 45 47 3 120 47 52 4 120 48 102 Ratio Released 6 1 153 51 125 2 153 60 80 3* 153 62 22 4 153 70 8 Ratio Released 7 1 92 59 108 2 92 65 24 3* 212 85 488 4 212 99 535 Ratio Released 8 1 190 39 27 2* 190 37 22 3 380 55 13 4 380 59 10 Ratio Released *Uncoated filter used ahead of nor_____ __________________________ they represent an insignificant portion of the ________. Finally, a word about the atmospheric stability. to obtain data during stable conditions (Pasqui____ at the time of the release of the UF6-SF6 mixture and 7 were stable conditions present. In the _____ was probably D or neutral. The limited amount not indicate any effect from the different stab_____ ___tion needs further consideration. This document No. 2 of REPOSITORY Oak Ridge/Energy Systems ORNC (X-10) COLLECTION Central Files BOX No. 48-6-375 FOLDER Title Radiological Warfare Program Date June 29, 1948 To K.Z. Morgan By J.H. Roberson Distribution 1. Karl Morgan 2. J.h. Roberson 3. Central Files 4. Reading Files CLASSIFICATION CANCELED DATE 8/28/67 For The Atomic Energy Commission Chief, Declassification Branch RADIOLOGICAL WARFARE PROGRAM A meeting to discuss Oak Ridge National Laboratory participation is Radiological Warfare program was held on June 28, 1948. Those attending were Oak Ridge National Laboratory A.E.C., Oak Ridge A.E.C. Military Applications C.H. Rucker F. Balcher E.J. Murphy M.D. Peterson J. Schilling 1 Lt. Col. L.B. Emlet Roth 1 Chemist E. Taylor J. Swartout J.H. Roberson Mr. Rucker explained the importance of the project, and expressed quite strongly his desire that Oak Ridge National Laboratory help as much as possible, even to the extent of shelving present problems. A deadline for the exploratory phase was set at September 1. Two experiments were requested by Murphy, an I was instructed by Mr. Rucker to participate in the planning as a representative of Health Physics, though the division is in no way committed as yet. You are expected to meet with the group immediately after your return, and to decide to what extent Health Physics can contribute. A later meeting with Emlet was held for the purpose of deciding what sources could be made available, and when. The conclusion reached was that sources requested could be supplied, and at just about the time they are wanted. Health Physics is expected to recommend source strengths for one of the experiments, and also measurement techniques. I am including herein some of my own opinions on the experiments requested by Murphy with the expectation that we will have to do the radiation measurement, and hoping that they will be of use to you in later discussions on details. 1. Measurement of the dosage rate due to a point source, from 10 ft. to 2000 ft. Sources - Ra La 10, 50 and 1000 curies in solution of 250 ml volume. Instruments - Electroscopes should be satisfactory. Assuming 1 per curie, then at 700 meters the dosage rate in mr/hr is 106/49x 104 or about 2 mr/hr. The air absorption (n - 4 x 10-5 ea-1), the half thickness is about 200 meters, so approximately 10% of the primary radiation is transmitted. Instrument background is 40.25 mr/hr; dosage rate is some 4 times background. Personnel - Three readings (3, 6 and 12 ft. above the ground) ar requested for each distance. Six men should be able to complete the data in one day, with time to spare. Perhaps we could get by with less. 2. Measurement of the dosage rate in an area approximately 2000 feet square, with 1000 sources distributed in a rectangular array. Sources - We are asked to recommend suitable strengths for the individual sources. I think 10 millicuries would be strong enough. The problem needs some consideration. Instruments - Survey meters, preferably ____. There has been no discussion required in this experiment. Personnel - This will be a long job, ____ __erations. I suggest as ____ __ers as we can muster. Mr. Stewart's division should be requested to _____ on the grid, and also mark positions where readings are _____. I have discussed the problem slightly with Jim Har_____ may be called on for men. Dr. Winche, of Hreokhaven, who planned the experiment arrive in Oak Ridge on Thursday. Original Signature J.H. Roberson JHRobersonirr MEMORANDUM TO: J.C. Franklin, Manager, Oak Ridge Dir_____ FROM: Walter J. Williams, Acting General Manager SUBJECT: RADIOLOGICAL WARFARE PROGRAM In connection with the program of the AEC staff certain information, studies and field tests are provide proper basis for recommendations by the Military Establishment Panel on Radiological Warfare. You are directed to make the necessary arrangements program as follows: 1. The production of sufficient radioactive out an initial field test using a single source. Williams to J.C. Franklin, Preparation of _____.. 2. The performance of the field test using radioactive lanthanum of appropriate strength for gram to be drawn up by personnel of the Oak Ridge in consultation with Dr. W. Winsche of the EW ____ (Appendix A, part I). 3. The production of radioactive tantalum ____ a second field test involving distribution of __________. 4. The performance of the grid type field detailed program to be prepared by personnel of Laboratory in cooperation with Dr. Winsche (Appe______). 5. An investigation of suitable methods ap_______ separation of radioactive fission products (spec ____ from IAW solution from the Redox process (Append______). 6. An investigation of production potential tantalum in present and projected piles at Hanfo personnel at Hanford (Appendix C). The results in order to be acceptable to the RW staff, should fully by the General Electric Company at Hanford. 7. An investigation of the availability of It is requested that action be taken under high the investigation of all these problems as rapid particular answers to questions under item 6 (Ap______ 15 August 1948. It is emphasized that the answer need not be of high accuracy but should be sufficient ___mendations to be made on the feasibility of using radiological warfare. Your assistance in carrying out this program will _________. Attachments Cys 3A and 4A of ltr to Carleton Shugg Evaluation of Radiation Losar Part I - Point Source One of the fundamental problems of HW is the evalu______ dosage at a point above a semi-infinite plane con____ distributed gamma emitter. Uniform distribution ___ physical basis in that it causes no excesses or ______. It may not be achieved in practice but will serve comparison with other distribution patterns. Before reliable calculations can be made regarding expected under various conditions, it is necessary understanding of the effectiveness of the scattered the air, ground and other objects which may play a _______. It appears feasible to obtain pertinent information matter by making measurements using a single source placed on a relatively flat, clear area approximate _____ length with no major obstructions intervening. The gamma emitter which is of immediate interest ____ obtainable is radioactive lanthanum. Sufficient ____ material can be produced in the Clinton Reactor. The following is a general outline of the field te______ use of a single gamma emitter. 1. The source should be as near the ground as pos_____ maintain an unobstructed straight line between detector. 2. Measurements should be made for each source di______ 3, 6, and 12 feet from the ground. 3. It is desirable to have measurements made at p____ lateral distances between source and counter ___ 200, 400, 750, and 1,000 feet. Data taken at from the source would be useful if cleared are_____ strength will permit. 4. It is believed that the strength of the source order of 1,000 curies. (A memorandum from Wal____ J. C. Franklin dated June 29, 1948 covers such preparation of a source of radiolanthanum for ________. The data desired are quantitative measurements of radiation intensities at the designated points. a wooded area or hill in the vicinity of the source not affect the results appreciably. The test should during dry weather if possible. If at all possible the actual test should be start July 15, 1948. Evaluation of Radiation Dosag___ Part II - Uniformly Distributed Source In order to gain information regarding the effec____ emitting source distributed uniformly over an ar___ prepare about 1,000 small sources and place them fashion on a suitable area. Instantaneous value intensities at various points would then be made detector. The most practical material, when considered from radiation characteristics and availability, is ___. Small specimens in the form of reds or wire may ____ able containers and irradiated in the X-10 react____ ation will be governed by the minimum activity r______ field test measurements of such magnitude as to _______. The area covered by the distributed sources shou_____ 300 yards on the side and preferably greater. It will be desirable to make measurements with d______ that is to say, the distances between sources ma_____ or more sets of measurements as well sa the amou__ material at each point. It is rather important that the strengths of the be as uniform as possible. This may be accompli____ all the specimens in a region of the reactor when____ density is reasonably uniform or in case of _____ quantities of tantalum may be packaged in the ______. It is not feasible at this time to specify the e_______ each source or the distances between them. Thes_ by such factors as the type of electronic detect for placing sources, shielding requirements, etc. for one or more RW staff members to maintain clo____ working groups at ORNL to carry on discussions r______ arrangements and specifications. Recovery of Fission Products from Hanford The recovery of specific fission products from p_____ wastes or future Redox process wastes is conside_____ choice of Zr and Ob recovery has been based on _____, high fission yield, hard gamma radiation secures for chemical recovery. The Joint Planned Military Establishment have been questioned regarding the development of a radiological weapon and cor____ not recovery from present Hanford wastes is nece_____ is received, it is suggested that the recovery __ Redox solutions be studied. On the Hanford plant scale the LAW waste solutic____ 1,500 gallons of aqueous solution with the follo____ composition: 0.6 M HNO3, 1.3 M Al(NO3)3 (or 4 __ 0.05 M Na2Cr2O7 and, in addition, is hexone sat_____ also contains over 99% of the fission products, original U and less than 0.1% of the original P_____. Neither the final form nor the radiochemical or the separated isotopes can be specified now. Th____ developed should be as flexible as possible with factors. Possible modes of recovery involve pre_____ extraction and adsorption or ion exchange. Precipitation of specific carriers for Zr-Cb mig____ although high salt concentrations might interfere separation of Zr-Ob from the carrier be required. Extraction of Zr into benzene using TTA as the ______ promising (CN3733, UCRL70). Very few ions are _____ chemical purity should be high. Columbium however __________. High extraction coefficients for Zr were found ___ synthetic solutions (R.E. Connick, personal cor_______ experiment with pilot plant IAW solution poor ex_____ (H. Hyman). The radio-colloidal form of Zr is _____ importance in determining the extraction of Zr. Adsorption of Zr and Cb an inorganic materials ____ resins followed by selective elutriation with _____ citric) also appears promising. The resulting ______ relatively pure and with a high specific activi______. It is suggested that several of these methods be program. Samples of LAW solution may be obtained National Laboratory Redox Pilot Plant. Appendix C Tantalum Irradiation at Hanford The following information is required in order to production capacity of Ta by irradiation of this Hanford piles. No decision has been made concerning and physical form in which the Ta may be present. It is suggested therefore, that several forms of (solid slugs, powdered metal, powdered oxide, cc since certain space requirements must be satisfied in hour requirements. 1. Estimate of the maximum quantity of Ta182 w manufactured per month through 1949 in acco_______ assumption shown in Cases A and B, below. 2. The feasibility of building up to equilibri____ January 1, 1950, an inventory of (a) 1 megs (b) 10 megacuries of Tz182 in accordance with made in cases A and B, below. If it is not up these inventories, information is desire inventory could be built up for each of the __________. Case A (1) Present method of operation. (2) No interference with postum of ________. Case B (1) Modified method of operations U235-Al alloy slugs in select____ piles. (See memoranda of H. ____ JW. R.Kanne for Armed Forces-A of May 23, 1948, for suggested ________. (2) No interference with postum ____ possible interference with Pu______. To: K.L. Morgan Subject: ABBUU Project The single source experiment is expected to be run on Friday, July 16, or as soon thereafter as practical. The source run was finished on July 12 at 7:45 A.M. and will reach a maximum on Saturday, July 17. The experiment may be postponed if preparations are not complete, or if the weather is bad. Details of the plan are outlined herein for your information and criticism. 1. Sources - Three, estimated to be 1000, 100, 10 curies respectively. They will be contained in standard stainless steel cones, with a stainless steel insert bolted to the cones as a cover to prevent loss of source material. Carriers for all three will be the standard 3500 pound carriers. 2. Field Preparations S. Tatalovitan has been assigned by Mr. Stewart's division to expedite the job. a) A graded strip, all vegetation and heaps to be removed, so that there is a clear line from the source to all measuring points. b) The strip to be chained and staked every hundred feet, with the first hundred feet subdivided into ten feet intervals. c) Elevation readings to be made at the stakes. d) A hole to be dug at the zero point so that the carrier can be lowered until its top is approximately flush with ground level. e) A frame to be built above the zero point, with pullay and long rope, for raising the source out of the carrier. Guy lines will be attached to the source to insure its re-entry into the carrier. f) The access road will be repaired sufficiently for our use. g) A six foot scaffold will be placed on a truck for taking the 12 foot reading. The 3 foot reading will be made with the observer on the ground and the 6 foot reading with the operator on the truck. h) The source carriers will be removed from the truck and placed in the hold by riggers, who will work around the source only when the lid is on. 3. Experimental Technique We have done little planning on this item as yet. I have convinced Coveyou (I hope) that ___________, window closed, will give us the answer we want. We have yet to get instruments, calibrate them and instruct operators. 4. Safety Precautions All our plans have been based on what we think will be safe procedures from the Health Physics viewpoint. We intend to run the weakest sources first which will give us an accurate measurement of what the 1000 curie source will produce. 5. Personnel We have no exact plans at this time. I anticipate asking fee about six people for one or perhaps two days. Original Signed By J.H. Roberson JHRoberson:rr cc: R.R. Coveyou S. Tatalivitch K.H. Morgan (3) J.H. Roberson OAK RIDGE NATIONAL LABORATORY Division of Carbide and Carbon Chemicals Corporation Oak Ridge, Tennessee Subject: Single Source Lanthanum Test - AHRUU Program. The experiment was conducted in a large field near the X-10 area by members of the Health Physics Division of Oak Ridge National Laboratory under the supervision of Dr. JohnH. Roberson. The general outline of the test was given in appendix A of a memorandum from Walter J. Williams to J.C. Franklin, dated July 2, 1943. The outline was as follows: 1. The source should be as near the ground as possible and still maintain an unobstructed straight line between source and detector. 2. Measurements should be made for each source distance at heights of 3, 6 and 12 feet from the ground. 3. It is desirable to have measurements made at points with lateral distances between source and counter of 10, 20, 50, 100, 200, 400, 750 and 1,000 feet. Data taken at greater distances from the source would be useful if cleared area and source strength will permit. 4. It is believed that the strength of the source should be of the order of 1,000 curies. (A memorandum from Walter J. Williams to J. C. Franklin, dated June 29, 1948, covers authorization for the preparation of a source of radio-lanthanum for this purpose.) The barium separation was finished at 8:00 a.m. on July 12, 1948, by the Operations Division under L. B. Emlet, Director. Analytical measure of the total material gave 1,400 curies, which was divided into three sources of about 1,280, 100 and 20 curies. The sources were used on July 17, when the amount of lanthanum was a maximum. A strip 10 feet wide and 1,900 feet long was cleared of vegetation and graded by the Engineering and Maintenance Division, Mr. J. C. Stewart, Director. The strip was leveled to within an estimated 1 foot tolerance, except for a dip between 1,300 and 1,700 feet, where the point of minimum elevation was about 6 feet below the source level. Distances from the zero point were measured and staked by a surveying crew. The source carrier was placed in a hole at the zero point, so that the top of the carrier was at a ground level. The source was raised from the carrier to a height 9 inches above ground level, by means of a ________ and pully on an overhead frame. Measurements were made at 3, 6 and 12 feet from the ground. The electroscope was used in preference to a Geiger-Muller counter because of its greater accuracy in measuring roentgens. Lauritsen electroscopes were used, the chamber of which was surrounded by 1/4 inch plywood. Distances from source to electroscope are shown on Figure 1, together with the results of the measurements. The ordinates in Figure 1 were computed by multiplying the reciprocal of the time of discharge of the electroscope by the quare of the distance from source to instrument. The values are corrected for background, which was 1/5 of the total intensity at 1,900 feet. The segment of the curve taken with the medium source was fitted to the large source curve at 500 feet. The data on the smallest source was fitted to the medium source at 100 feet. A large portion of the drop in the measured value of intensity times distance squared, apparent for all three sources at small distances, is undoubtedly due to non-saturation in the electroscope chamber in high-intensity fields. Time does not permit further investigation of this result. The readings at 3, 6 and 12 feet do not differ appreciably at great distances, except at the 1,600 foot position, where the 3 and 6 foot elevations were below the ground level and shielded from the direct beam. At near distances any variation would have been obscured because of the high radiation intensity of the direct beam. At the 600 foot distance a reading was made beside the truck, and another with the truck moved back to 700 feet. The two readings differed by less than __ so the scattering from the truck did not introduce a serious error in these measurements. Each measured value is the average of three readings whose internal consistency was better than 3%. The extrapolated value may be low by as much as 10%, though this is doubtful because of the good agreement between the small and medium source value at 200 and 100 feet. Experimental results The half thickness of the straight portion of the curve is 450 feet (130 meters) corresponding to a coefficient of absorption of 5.3 x 10-5 cm-2 of air or a relaxation distance of 650 feet (190 meters). _________________________________ K. L. Morgan Director, Health Physics Division _________________________________ C. H. Rucker Executive Director JHRoberson:mcs - Fig. 1 - La SOURCES FOR REFERENCE SEE (4bb10) Attachment #6 Attachment #7