DECLASSIFIED HW-17381-NOTES This Document consists of 67 pages General Electric Company Copy____ of _____ Hanford Atomic Products Operation Series______ Richland, WA Title: Dissolving of Twenty Day Metal at Hanford - Notes 701579 Date: Undated Classification cancelled Change to: By Authority of: By: Author: Unknown Department: Circulations Restrictions: CRS Code: External Distribution Internal Distribution DOCUMENT NUMBER WAS ASSIGNED AT TIME OF DISCOVERY IN JANUARY 1993 ROUTE TO DATE PAYROLL NO. LOCATION READ BY DATE REPOSITORY: PNL-300 AREA, HARTFORD TECH. LIBRARY COLLECTION: HANFORD HISTORICAL COLLECTION FROM CMCC BOX NO.: OPEN SHELVING FOLDER: HW-17381 DISSOLVING OF TWENTY DAY METAL AT HANFORD FILE CIRCULATING COPY RETURN TO: TECHNICAL INFORMATION FILES MAY 1, 1950 CLASSIFICATION CANCELLED WITH DELETIONS BY AUTHORITY OF DOE/OG Leo D. Sullivan 7/1/89 REVIEWED BY DATE GENERAL ELECTRIC NUCLEONICS DEPARTMENT HANFORD WORKS RICHLAND, WASHINGTON DECLASSIFIED DISSOLVING OF TWENTY DAY METAL AT HANFORD by D. E. Jenne and J. W. Healy May 1, 1950 HANFORD WORKS RICHLAND, WASHINGTON Operated for the Atomic Energy Commission by the General Electric Company under Contract #W-31-109-eng-52 HW-17381 COPY NUMBER INTERNATIONAL DISTRIBUTION 1 H. M. Parker - C. C Gamertsfelder 2 C. M. Patterson 3 H.A. Kornberg 4 A. B. Greninger 5 C.N. Gross - R. S. Bell 6 H. J. Paas 7 8 Pink copy 9 Yellow copy 10 700 File 11 300 File 12 - 17 Extra copies EXTERNAL DISTRIBUTION 18 - 21 Hanford Operations Office 22 - 33 Hanford Operations Office B SERIES DISTRIBUTION 1 thru 3. DOE/RL - MJ LAWRENCE 4. 300 FILES - EXTRA 5. 300 FILES - EXTRA 6. 300 FILES - EXTRA 7. 300 FILES - EXTRA 8. 300 FILES - EXTRA 9. 300 FILES - EXTRA - 3 - HW-17381 I. SUMMARY One ton of irradiated uranium with fifteen days cooling was dissolved from a two ton batch loaded into a clean dissolver on December 2, 1949. Calculated amounts of activity evolved were 4000 curies of I-131 and 7900 curies of Xe-133; measured values here higher than this by a factor of 2 to 3. Preliminary calculations of the hazard were made by the method of 0. G. Sutton and attempts made to check these values by readings on fixed and mobile instruments. The meteorological conditions during the actual hours of unstable with the wind veering from a southerly direction at the start to a northerly direction about half-way through the run. Rawinsonde readings at Richland during the run indicated a shallow surface inversion with an unstable condition aloft. It is postulated that much of the dilution occurred above the inversion. Readings as high as 2 x 10-4 uc/1 of I-131 and 2000 to 3000 c/m on portable Geiger counters here obtained within a radius of 4 to 5 miles from the stack. Significant readings appeared in the Richland - Pasco - Benton City area about noon of December 3. Estimated maximum concentrations were on the order of 10-7 to 10-6 uc/1 of I-131. Questionable positive readings were obtained on filters at Spokane on December 3 and December 5, 1949. Aircraft measurements made in the direction of Spokane on December 3, 1949, indicated peak activities in the morning at Ritzville and between Richland and Connell. It is postulated that the peak closest to the project was due to I-131 while the one at Ritzville was due to Xe-133. Considerable deposition occurred particularly close to the stacks. Positive vegetation readings, above the permanent tolerance value of 9 muc/kg occurred over a region extending frog Tho Dallas, Oregon, to Spokane, and from Yakima to the Blue Mountains. The rate of deposition in water was estimated at 2 x 104 uc/meter3/hr/uc/1; and on vegetation as 4 x 105 uc/meter/hr/uc/1. The I-131 on vegetation decayed to background with an eight day half-life. Exposures of clean potted plants in the area gave results comparable to those found in other plants. Animals collected from the region indicated that specimens from within the project boundary received thyroid irradiation varying from tolerance to 80 times tolerance daily. - 4- HW-17381 DISSOLVING OF TWENTY DAY METAL AT HANFORD INTRODUCTION The Health Instrument Divisions were interested primarily in obtaining monitoring results to see that no one was overexposed to the active fumes, and secondarily in the travel of the activity and deposition on the vegetation. Since it is almost impossible to write such a report without designating areas, buildings, terrain features, etc. by their local names, Figure 1, included in the introduction to the report, is a map showing the location of the more prominent features. - 5 - HW-17381 II. PLANNING Upon receiving this information, each group participating started more detailed Ark directed towards obtaining as much information as possible from the operation land Boeing that the fumes were liberated safely. An outline of this planning is given below since much of the work done at this time aided considerably in interpreting results. A. Weather Required. With this amount of activity being released, good dilution of the fumes before The came to the ground in the areas wore required to avoid gross contamination of the buildings land possible exposure of personnel. Criteria decided upon for weather conditions were: (l). An inverted vertical temperature gradient extending from the ground to several hundred feet above. This stipulation necessitated scheduling the run during nigh-time, as it is only then that inversion conditions at Hanford Works are frequent. (2). No rain, fog, low cloudiness, or other factor which might prevent this plan from flying. (3). Light to moderate wind speeds 15 mph at the 200 ft. level was decided upon is tho upper limit of permissible wind speed. (4). Wind from a westerly or southwesterly direction 80 that the plane would not be forced to fly in the vicinity of such rugged topographic features as 3600 HW-17381 - 6 - feet high Rattlesnake Mountain to the south of the area. (5). Conditions whereby the bulk of the stack effluent would stay aloft. A factor of 1500:1 was decided upon as the lowest permissible factor. A review of data from the past several years at the HW Meteorology Station showed that during night hours at this season of the year the "aloft" condition prevailed 76% of the time, and that the sky coverage averaged 6.7 on a scale of 10. Hourly wind speeds between 0300 and 1200 averaged from 4-6 mph at the 7 feet level to 10-11 mph at the 400 foot level. The prevailing direction was northwest. A moderate inversion usually overlies the area at night, forming near sunset and terminating about one-half hour after sunrise. Normally, precipitation is infrequent and the probability of its occurrence during any particular 24 hour period is always small. The above statistics indicate that the chance of finding favorable meteorological conditions for the dissolution on ~ particular date might be good. However, the month of November, 1949, was placed with inclement weather which included two periods of recurrent storms with attendant wind and rain, interspersed by a 10-day stagnant period during which ceilings were continually low and fog was present on an average of nearly 10 hours each day. This inclement weather necessitated postponement of the run for one week. On the morning of December l, the United States weather Bureau in a special forecast to this plant, predicted that the end of the current series of frequent storms was n sight, and that condition favorable for the operation could be expected by Saturday night, December 3. The dissolver was then loaded so that operations could begin Friday night, December 2, if conditions were favorable. B. Operations The "S" Division, in charge of the actual dissolving elected to use the spare dissolver in the "T" plant (200 West Area) so that the "heel" resulting from the dissolution of only a portion of the metal charged, could be stored in the dissolver for an additional cooling period. Two tons of metal pushed on November 17, - 7 - HW-17381 were loaded into a clean dissolver on December 1, 1949, and the jackets dissolved on the 12-8 shift on December 2, 1949. The actual length of the dissolving time could not be predicted accurately since normal operating procedure calls for three tons of metal per charge on top of a one ton heel. An estimate of 12-16 hours for the dissolution of one ton was made. The amounts of 1-131 and Xe-133 in the metal after 16 days cooling were estimated at 6150 and 6070 curies per ton respectively. Assuming that 50% of the iodine (2) remains in the dissolver and that there is a 30% increase over the average in the amounts of fission products in the outer portion of the slug, the dissolution of one ton would liberate 4000 curies of I-131 and 7900 curies of Xe-133. Since the off-gas scrubbers were not operated, all of this activity would be discharged from the stack. The rate of discharge was estimated from three evolution curies measured in 1947 by the H. I. Division. These curves indicated that with an eight hour dissolving period the Xe-133 reaches a maximum in 1-1/2 hours and the I-131 reaches a maximum in 3-4 hours. Extrapolation of these curves to a 16 hour dissolving (fig. 2) indicated a xenon peak at about three hours and an iodine peak at about seven hours after the start. The maximum rate of omission was estimated at 0.41 curies/sec for Xe-133 and 0.14 curies/sec for I-131. These values would amount to about 28 uc/1 of X3-133 and 10 uc/1 of I-131 in the stack on the basis of an air flow of 25,000 cfm up the stack. The start was planned for 20000 on December 2 as a compromise between the Air Force's desire to start at 0100-0300 on December 3 so that the maximum would occur about daybreak, and the operation's need to start as soon after sundown as possible so that the bulk of the activity would be liberated before the inversion broke the next morning. With the start at 2000, the maximum Xe-133 activity would occur about midnight and the maximum I-131 activity would occur about 0300, with a total of 12 hours before sunup to eliminate most of the activity. - 8 - HW-17381 C. Air Forcer Extra weather forecasting and observation stations were set up by the Air weather service to augment existing stations in order to obtain sufficient data for forecasting the movement of the cloud and to correlate the existing conditions with the activity pattern found. Reports of forecasting and observation stations over the Northwest were utilized to get a clear picture of the weather for weeks before the test. In addition, a mobile Hawinsonde station and two pibal units were moved into the vicinity of the Hanford Project for a more detailed analysis. The Rawinsonde unit was placed at the Richland Airport and one each of the pibal stations at Washtucna and Moses Lake. Background values were established for the aerial instruments prior to the run. Flights were made at different altitudes over the area and the instrument valves were plotted against altitude changes. A set of curves for the principal instruments appears in the section on equipment and procedures. The. H. I. Site Survey Crew interested in checking upon the hazards encountered in the run plus any information that could be obtained upon the spread or deposition of activity. A series of calculations based on the work of O. G. Sutton and others on the dilution of gases in the lower atmosphere were performed (2,4,5,6). The basic equation for these calculation is: D. Site Survey The H. I. Site Survey Crew was interested in checking upon the hazards encountered in the run plus any information that could be obtained upon the spread or deposition of activity. A series of calculations based on the work of O. G. Sutton and others on the dilution of gases in the lower atmosphere were performed (3,4,5,6). The basic equation for these calculations is: - 11 - HW-17381 balloon to several hundred feet so that traverses of the cloud at the axis could be made. (3). One man was to travel from the intersection of routes 4S and 2S to several miles above Hanford reading detachable chambers every mile and taking a small scrubber and portable GM readings. (4). Two men were to travel from Pasco to Connell with a recording GM counter and a 1-1/2 CFM air scrubber operated from a mobile generator. (5). One man was to check all instruments during the run and to take small scrubber samples on the reservation. E. Coordination In order to keep current with activities in the field during the time of evolution, the H. l. Emergency Plotting Room at Patrol Headquarters was used. This allowed the use of three telephones and was conveniently located at WGMB, the patrol radio station. Thus it was possible to obtain reports from the field cars by radio, from various survey groups by telephone. This also allowed the use of the plotting room facilities in conditions approximating those of an actual emergency and was very valuable in gaining information on techniques. The plotting room was manned by Health Instrument Personnel from 1900 on 12/2 to 1000 on 12/3 and by an Air Forces representative from 0100 on 12/3 to 1000 on 12/3. HW-17381 - 12 - III. Equipment and Procedures In general, a brief discussion of the equipment and procedures used for a particular reading or series of readings is included in the section presenting the date. This section of the report is intended to describe those items which were used generally throughout the run and procedures which were used in the analysis of samples, etc. A. Air Forces 1. Atmospheric Conductivity Apparatus The Atmospheric Conductivity Apparatus is essentially the same unit that was used on previous tests. 1 The only change is in the method of signal amplification and recording. A vibrating-condenser monition and an Estorline-Angus Recorder replace the vacuum-tube electrometer circuit and Brown recorder. The vibrating condenser converts the D.C. potential developed across the capacitor by a collected charge from the collection tube, into an A. C. voltage which is then amplified, rectified, and measured in a vacuum-tube voltmeter circuit. This monition is built around a modified berating condenser which was used in the APN-2 radar altimeter (Part Y-101, Stock No. P255062-501). Modification of the condenser included the addition of a material of high insulating properties between the plates and electroplating the vibrating diaphragm with 24-karat gold. A two-stage AC amplifier, a rectifier, a vacuum-tube voltmeter stage, and an oscillator for the vibrating condenser comprise the vacuum-tube unit in addition to the conventional power supply. The ionization rate is recorded on a -0-1 milliammeter in the form of the Estorline-Angus recorder. There is an additional indicator on the pilot's instrument panel. Two ranges are available on this extremely stable monition, a switch on the front panel allows the operator to choose the most suitable range for the job. These ranges differ by approximately a factor of tan, with Victorian Hirmsgprocis- -13- HW-17381 A schematic diagram of the monitron appears in Figure 8 and a photograph of a complete monitoring set up in Figure 9. However, it will be noted that the collecting tube shown here is considerably shorter than that used in the aircraft. (The setup shown is for ground monitoring at a low velocity air flow.) 2. N.R.L. Dual-Channel Airborne Unit This unit was described more fully by the designers (7). However, because the "C" channel went out just prior to the run, the set was used as a straight counting rate meter with no coincidence cancellation. The tube bank was different from these originally used. Instead of the metal counters, glass counter tubes were inserted into 1" brass sleeves by the instrument division to give approximately the same density as the metal counter. 3. AMC Filter Box A standard AMC filter box is mounted on the aircraft in the position shown in Figure 10. It accommodates two 8" x 18"filters and passes about 450 cubic feet of air per minute through each filter at 150 miles per hour indicated airspeed. 4. External Counter Tube For the first time on the project, an external beta counter was used. The assembly consisted of a Tracer lab stainless steel counter tube mounted atop the filter box on two aluminum brackets. A deflector cap shielded the tube from the direct blast of the slip-stream and also covered the co-axial connection. The co-axial cable passed through the front mount and terminated at a pro-amplifier just inside the cabin of the aircraft. Pulses from this cathode-follower stages were fed into a scaler for counting. When the tube was subjected to near freezing temperatures it practically passed counting. However, under warmer conditions the performance was very good. A sketch and photographs of the assembly follow in Figures 11, 12, 13. 5. Scrubber Installation The Health Instruments Division installed in the aircraft a system de----- HW-17381 DECLASSIFIED WITH DELETIONS 701570 -1- HW-15550-E DEL BEST AVAILABLE COPY COPIES #1-17 - Plant Monthly Report 18- CN Gross 19 - WD Norwood - EC Berry 20 - HM Parker 21 - CM Patterson 22 - CC Gamertsfelder 23 - PC Jerman - WA McAdams 24 - JG Myers - LV Barker PR Mc Murray 25 - LC Roos - AR Keene 26 - HA Kornberg - WC Berlin 27 - J Katz - RC Thorburn 28 - JW Healy 29 - KE Herde - RF Foster - MH Joffe - JW Porter 30 - LW Finch 31 - LL German - Schenectady 32 - PL Eisenacher - GH Whipple 33 - HC Money - DP Schively 34 - 300 File 35 - 700 File 36 - Pink File 37 - Yellow File 38 - Estra File Copy HEALTH INSTRUMENT DIVISIONS REPORT FOR MONTH OF DECEMBER, 1949 HEALTH INSTRUMENT DIVISIONS DECEMBER, 1949 Summary The force increased by four. Three Class I Special Hazards Incidents were investigated. None of these involved significant radiation exposure. Survey findings in the Operational Division, with some exceptions were normal. The "special dissolving" resulted in greater contamination spread than had been anticipated. Air and vegetation samples collected by Development Division personnel defined the resulting pattern and magnitude of I-131 deposition. Other routine monitoring samples were consisted with past findings. In Bioassay, urine samples showed no confirmed positive results for plutonium but disclosed consistently high tritium oxide content in the samples from two individuals. In biological monitoring, specimens collected during the month showed thyroid activities ranging from 1 to 300 uc/kg - the latter represents about 80 times the maximum permissible limit of permanently maintained radioiodine concentration. This resulted from the high deposition of I-131 in the special dissolving, and is a temporary condition. Phase I of the Animal Farm is being accepted as opposed to Phase II, the sewage disposal plant, which does not most operating specifications. DECLASSIFIED WITH DELETIONS HW-15550 Health Instrument Divisions HEALTH INSTRUMENT DIVISION DECEMBER 1949 Organization The composition and distribution of the force as of 12/30/49 was as follows: 100-B 100-D 100-F 100-H 200-W 200-E 300 700 P.G. Total Supervisors 1 1 3 2 9 3 14 60 o 39 Engineers 3 3 15 2 16 10 9 4 0 62 Clerical 0 0 1 1 1 2 3 4 0 12 Others 10 13 35 13 69 26 56 9 8 239 Total 14 17 54 18 95 41 82 23 8 352 This represents an increase of 37 people or 12 percent during the year. The increment is far below that projected because of (1) inability to hire key specialists in soil science and meteorology (2) delay in expected completion of laboratory facilities. Number of Employees on Payroll December 1949 Beginning of month 348 End of month 352 Net increase 4 Additions to the roll were one engineer, 6 laboratory assistants, one badge worker, 4 general clerks and a steno-typist. Removed from the roll were an assistant to the manager, senior supervisor, 4 engineers, 2 laboratory assistants, and a general clerk. General Widespread contamination by I-131 occurred as a result of a specially requested dissolving at short cooling time. The prediction that this could be accomplished once with negligible risk to personnel was supported by the experimental observations. However, the resultant activity came close enough to significant levels, and its distribution differed enough from simple predictions that the H.I. Divisions would resist a proposed repetition of the test. Three Class I Special Hazards Incidents were investigated. Two involved failure to follow standard procedure, and the other failure to follow special work permit instructions. As the Special Hazards Committee is in no way a disciplinary body, it has been decided that such incidents will in future be reported. HW-15550 Health Instrument Divisions CONTROL AND DEVELOPMENT DIVISION Site Survey The number of routine samples processed this month was curtailed to allow full coverage of the "green run." The activities found in various water sources were consistent with past findings. A series of small very active pieces of material (up to 3 rep/hour at a distance of about 3 inches with a C.P.) was found by the Survey Group near the "C" diversion box in the 200 East Area. Analyses of these particles indicated the presence of rare earths and strontium but no ruthenium. The particles are about the size of weed seeds or mouse feces. Further analysis and investigation is being carried out by the Biology Division, the Survey Group, and Site Survey. On the night of December 2, 1949, one ton of metal with 16 days cooling was dissolved in the 200 West Area. At the time of the run Site Survey measured I-131 air concentrations as high cs 3 x 10 -6 uc/liter averaged over a 24 hour period in the areas and 3.4 x 100 -8 uc/liter over a four day period at Benton City. The could apparently blew back over the area the day after the run since scrubbers stared on the 3rd at Benton City and Richland showed more activity than the one operating during the run. Pans of water at various locations near the areas picked up as much as 90 uc of I-131 on a one square foot area of water. Thirteen hundred and sixty-five vegetation samples were taken in anarea extending from Klamath Falls to Kettle Falls and from Lewiston, Idaho to Portland, Oregon. The most active sample from the area within the 200 West fence contained 28 uc/kg. Activity exceeding 10 uc/kg was not uncommon inside the separation areas and along route 3 between the ares. The pattern of deposition is elongated in a northeast and southwest direction. The average activity in the Horse Heaven Hills near Kiona was on the order of 1.0 uc/kg with a maximum of 4.3 uc/kg at Kiona. Wahluke Slope deposition was in the range of 0.1 - 0.5 uc/kg with two small isolated a reason the order of 0.5 - 1.0 uc/kg. A long narrow strip of deposition between 01. and 0.5 uc/kg included the communities of Goldendale, Arlington, Plymouth, Walla Walle, Odessa and Moses Lake. A complete report on the data from this run will be issued. For comparison, the permissible permanent concentration on vegetation is taken as 0.01 uc/kg. Where the concentration is not maintained, the initial permissible limit is at least 12.5 times higher, and it more probably about 50 times higher. The observed deposition is higher than was anticipated. The direct hazard to man depends on the atmospheric concentration, and this remained at acceptable levels. August 2, 1945 I. Introduction During the dissolution in nitric soil of uranium metal which has been irradiated in a pile, radio-iodine (6.0 day) and radio-xenon (5.3 day) are liberated along with the oxides of nitrogen. Since in the plant these gases are discharged into the atmosphere, the presence of the activities (particularly radio-iodine because of its greater chemical reactivity) presents a physiological hazard. As a consequence, the cooling period (that is, the time between the discharge of the metal from the pile and the dissolution of the metal in nitric acid for the extraction of the product) should be sufficiently long so that the activities will have decreased through decay to the point where their concentrations in the atmosphere will not exceed 2.5x10-13 curies/cc and 5x10-11 curies/eg for radio-iodine and radio-xenon, respectively. Before the start of operations at H.E.W. a study was made of the existing information (largely from Site X) concerning the liberation of iodine and xenon during the dissolution of the metal and the information was summarized in a memorandum.(1) At thtat time it was apparent that radio-iodine would present the greater hazard, and that very little was known about the factors governing the liberation of iodine during the metal dissolution. For this reason, an investigation of the factors involved in the liberation of iodine during metal dissolution was undertaken in the laboratory. At the start of the investigation it appeared that the problem could be divided in two parts: (1) evolution of iodine from the uranyl nitrate solution, and (2) escape of the iodine past the reflux in the dissolver column and a through the off-gas line. It was considered that the following factors might possibly influence the evolution of iodine from the uranyl nitrate solution: (1) concentration of iodine, (2) concentration of nitric soil, (3) concentration of uranyl nitrate, (4) the ratio of the surface of the metal to the volume of the solution, and (5) the temperature. Since the temperature is fairly definitely established in the plant at 105øC-110øC, and since the rate of evolution is probably dependent on the surface to volume ratio to no more than first power, the investigation was focused on the first three variables. Of the many factors that night possibly influence the escape of the iodine, only the absorption of iodine in the reflux was investigated, since date obtained by the Health Instrument Section suggested that the reflux in the dissolver column greatly retarded the rate of discharge of the iodine. II. Summary and Conclusions From the data presented in this report and discussed more fully under the heading "Discussion", the following conclusions may be drawn with respect to the discharge of iodine during the dissolution of irradiated uranium metal in nitric acid: (1) The evolution of iodine from the uranyl nitrate solution is principally influenced by the concentration of iodine and is substantially independent of the concentration of nitric sod or uranyl nitrate. The reaction involved in the evolution of iodine appears to be approximately a second order reaction with respect to the concentration of iodine and to have a reaction rate constant of 0.051/mg of iodin/mir. (2) The above conclusion is qualitatively substantiated by plant data. Tolerance concentration for an eight hour day (of CE-690 and CH-504 - 2 - (3) The addition of iodine (inactive) either as iodide or as iodate only slightly increases the rate of evolution of the active iodine from the uranyl nitrate solution. By visual observation, the added iodine, however, is evolved quickly from the solution. This suggest that the active iodine in the uranyl nitrate solution does not exist as either iodid or iodate. Although the state in which iodine exists in the uranyl nitrate solution is not known, very likely the iodine exists in a complexion, and in an oxidation state higher than L (since concentrated MIO oxidize iodine to iodate). (4) Under simulated dissolver conditions in the laboratory the reflux removed a large fraction (70% to 90%) of the iodine from the off-gases. (5) Analyses of the plant solutions (Run T-6-03-B-1) through the extraction step indicates (a) that about 48ø (on the basis of a fission yield of 2.8% for 8.0 day iodine) of the iodine remains in the metal solution after the metal dissolution step, (b) that about 25% of the iodine remaining is evolved from the uranyl nitrate solution before the extraction step, and (c) that a decontamination factor, with respect to iodine, of about 60 is obtained in the extraction step. III. Discussion A. Order of the Reaction and the Reaction Rate Constant On the assumption that the evolution of iodine would involve only the concentration of iodine and nitre soil, theappropriate date obtained in the experiments were substituted in the equation dI/dt = KxIXHNO3b. If values for "a" and "b" which resulted in a constant value for X could be determined, the dependency of the reaction involving the evolution of iodine from uranyl nitrate solutions during the dissolution of metal would be established. For this purpose the concentration of iodine and nitric acid during the course of the runs (at various concentration of iodine, nitric acid, and uranyl nitrate) were plotted in Figures 1, 2, 3, and 4. At a given time, the concentration of iodine (1), the concentration of HMO and dI/dt (the slope of the curve representing the concentration of iodine) were substituted in the above equation. The results of this substitution, using values of "a"from 1 to 3 and values of "b" from 0 to 1, are shown in Tables 1a, 1b, lc, and 1d. An inspection of the values of K given in the tables show that under all the varied conditions of the most constant value is obtained when "a" equals 2, and "b" equals 0, that is, the reaction is approximately second order with respect to the concentration of iodine and independent of the concentration of nitric soil. The values of K calculated from the equation - dI/dt = KI2 lack accuracy because of the freedom permitted by the data in the drawing of the curve representing the concentration of iodine. For this reason, after establishing that the reaction was most likely a second order reaction, the reaction rate constant was determined by plotting the reciprocal of the concentration of iodine with respect to the reaction time.** The straight lines obtained as a result of this plot are also shown in figures 1, 2, 3, and 4. The average reaction rate constant determined from the slopes of the straight lines is 0.05 1/mg/min. * At higher concentrations of product in the metal, and hence at higher concentrations of iodine, the percentage remaining in solution should be less. ** If - dI/dt = HI2 then - dI/I2 = K (ILLEGIBLE TEXT) FOR REFERENCE SEE (2bb55) HAND WRITTEN TEXT FOR REFERENCE SEE (2bb56) HAND WRITTEN TEXT - 30 - HW-17381 Surface Atmospheric Readings A. Field Crows Near Stack Two groups were operating near the stack with four-wheel drive equipment and assignments to make measurements in the most likely locality. One group was to use the transmitting Geiger Counter supported above the ground by meteorological balloons to obtain traverses of the cloud at approximately the axis. The receiver was operated from a mobile generate. This unit was in the field in line with the gases from the stack at 2030 on 12-2-49. The wind velocity during this period was about 15 mph which caused considerable drag on the balloons, and although there were nearly 400 yards of nylon cord attached to the balloon, the maximum height reached by the balloon was 75-100 feet. Only three readings were made with this unit, when the cord apparently frayed at the point that it crossed the guide from the winch and broke at proximately 2230. The unit was later found near Pleasant View, Washington a point about 55 miles away and 5ø south of east from the T plant stack. Three readings taken on the equipment are given in Table 8. Table 8 Balloon Readings Location Time c/m Background - 60 1000' N - 200 W Gate House 2140 1410 175' N - 200 W Gate House 2200 2350 100; N - 200 W Gate House 2215 3340 After loss of the balloon, this group joined in making readings with the second crew. The second field crow was assigned to locating the point of maximum deposition and making measurements and traverses. Immediate readings were made with portable GM counters held in the air; one cubic foot samples were also taken with small scrubbers designed to obtain the I-131 content. Considerable difficulty was encountered after about 2300 on 12/2 with shifting winds which made the location of any single spot to run the traverses extremely difficult. Again the point at which the maximum activity occurred appeared to considerably closer to the base of the stack than was inspected. Inadequate testing of the equipment used for simply was indicated when certain of the - 31 - HW-17381 hand pumps used for pulling the samples failed. The readings obtained by this group in the field are given in Table 9. Table 9 FIELD READINGS Readings TIME LOCATION VGM Scrubber Remarks c/m uc/1 2110 1000 yards. N 200 W Gate 750-1000 - Very narrow band of activity - approx. 20 paces 2135 1000 yards. N 200 W Gate 3000 - 2135 Route 3 mi. 1 & 2 500 2140 1000 yds. N 200 W Gate - 1.8 x10-4 2150 Route 3 mi. 1 - 1.9 x 10-5 At estimated edge cloud 2206 Route 3 mi. 3 3000 - 2220 Route 4 s mi. 1 1000 2224 3000 yds N. 200 W Gate 1200 2230 1/4 mi. W of Met. Twr. 3000 2.3 x 10-5 2235 Route 4S mi. 1 1000 4.9 x 10-6 2300 Route 4S mi. 3 1000 4.8 x 10-6 2307 200 W Gate 1500 - 2310 1/4 mi. SW of Met. Twr. - 1.3 x 10-5 2321 100-F Area 125 - 2334 Route 4S mi. 5 1000 - Inst. Contaminated 2335 Route 3 mi. 3 2500 - 2338 Route 4S mi. 7 1500 - Inst. Contaminated 2340 Route 4S mi. 3 2500 - Inst. Contaminated 2342 Route 4S mi. 9 800 - Inst. Contaminated 2345 Route 4S mi. 9 1000 - Inst. Contaminated 2350 Route 4S mi. 3 700 - Inst. Contaminated 2354 Route 4S mi. 15 800 - Inst. Contaminated 12-3-49 0022 Route 4S mi. 5 160 - 0029 Route 4S mi. 7 60 - 0035 Route 4S mi. 9 80 - 0040 Route 4S mi. 11 60 - 0045 Route 10 mi. 1 40 - 0050 Route 10 mi. 3 20 - 0054 Route 10 mi. 4 20 - 0055 Route 10 mi. 5 20 - 0108 Route 3 mi 1 500 - 0115 Route 3 mi. 0 2000 - 0155 200 W Gate 7400 Instrument later shown to have background of 2000 c/m 0155 Route 11A mi. 10 300 0202 Route 11A mi. 13 300 0217 200 East Area 1500-2000 General readings in area 0255 200 W. Gate 2000 2.3 x 10-5 0300 1/2 mi. S. Met. Twr. 3000 1.2 x 10-4 0305 Administration Bldg, 200 West Area 1500 6.1 x 10-5 - 32 - HW-17381 Table 9 (Continued) TIME LOCATION READINGS REMARKS VGM Scrubber c/m uc/1 0310 Near Power House Bldg. in 1500 7.7 x 10-5 200 West Area 0315 100 yd. N. 200 W Gate 0400 200 yd. N. 200 W Gate 2200 1.5 x 10-4 0405 300 yd. N. 200 W Gate 3000 1.1 x 10-4 0405 400 yd. N. 200 W Gate - 8.6 x 10-5 0512 Route 11A mi. 3 - 1.6 x 10-4 0520 Route 11A mi. 1 - 4.8 x 10-6 0535 Route 3 mi. 1 500 - 0545 1/2 mi. S. Route 11A, Mile 9 600 3.4 x 10-5 0620 Met Twr. 600 1.7 x 10-5 0620 S. Corner 200 W - 5.6 x 10-6 0626 200 y S Met. Twr. 600 1.3 x 10-5 0634 Route 4S mi. 22 60 - 0640 200 yd. W. Twr. #4 - 5.9 x 10-6 0640 SW corner 200 W 200 2.3 x 10-5 0641 500 yds. S. Met. Ter. 600 - 0643 50 t E. Stack 3700 - Electronic s GW 0650 1-1/2 mi. S 200 W 4000 - Victoreen GM 0655 Route 3 mi. 3 1100 2.1 x 10-5 0700 1-1/2 mi. SE 200 W 400 5.0 x 10-5 0710 2 mi. S Route 3 mi. 3 700 1.8 x 10-5 0715 200 yd. E 231 1000 8.8 x 10-6 0715 Route 3 mi. 3 - 6.2 x 10-6 0725 Route 3 mi. 3 400 3.7 x 10-5 0735 200 yd. SE stack 500 6.9 x 10-6 0740 100 yd SE stack - 4.4 x 10-6 0745 200 yd SW stack - 4.6 x 10-6 0745 1 mi. SE 200 W Gate 650 1.4 x 10-5 0745 1/2 mi. S.W. Gate 1000 1.6 x 10-5 As is apparent from the data above, considerable difficulty was encountered with contaminated instruments after about midnight. Immediately one man was sent down Route 4S to Richland. He reported readings of 1000-1500 c/m on a portable Geiger Counter all the way in, but a later check indicated about that much contamination on his instrument. Follow-up surveys between 0000 and 0600 gave background readings in this region. - 63 - HW-17381 IX. Biological Monitoring A. Botany Potted plants of wheat and winter peas were placed at five different stations throughout the area on the afternoon of December 2, 1949. These plants were left exposed until 1:00 p.m. on December 3. The stations selected were in the 614 Buildings throughout the Hanford Area to allow protection to the plants in case of freezing weather during the period of exposure to the gases. At Station #1, which was the 614 Building located at the center of the north fence in 200 West Area, one of each type of plant was placed inside of the building and one of each type of plant was placed outside of the building. The same procedure was followed for Station #2, 200 East Area west Center, Station #3, 100-B Area southeast, Station #4, 100-F Area southwest, and Station #5, North Richland north. The plants were as they had been growing in the greenhouse at the Botany Laboratory at 100-F Area except for the wheat plants, which were placed at Stations #1 and #2. The soil of these plants was covered with a lawyer of paraffin to separate the soil from the atmosphere. After the plants had been exposed to the radioactive gases, they were brought back to the Botany Laboratory. Samples were immediately taken from the plants and on gram portions counted directly on the first shelf of a mica window counter. Plants which were placed outside of the building at Station #1 and #2 accumulated the most activity. The average activity in microcuries per kilogram for the aerial portions of these plants were as follows: Station #1 Station #2 Winter peas 1.0 Winter peas 2.1 Wheat 1.7 Wheat 2.2 - 64 - HW-17381 The samples of those plants which were placed inside the building at Station #1 and #2 had average activity of less than 0.1 microcuries per kilogram for the serial portions of the plants. Samples from the plants placed both inside and outside at Station #3, #4 and #5 had average activities of less than 0.01 microcuries per kilogram. The counting results of the roots of the wheat plants places outside the building at Station #1 showed the average activity to e 0.02 microcuries per kilogram. For the roots of wheat plants outside at Station #2, the average activity was 0.05 microcuries per kilogram. B. Zoology As a followup on the special dissolving of December 2, considerable emphasis was placed upon the collection of birds (principally fowl) and mammals from arbitrary locations on and near the reservation. A total of 68 animals were assayed for iodine131 in the thyroids. Levels detected in birds and mammals are given in Table 22: Table 22 Summary of Activity in Birds and Mammals BIRDS MAMMALS Location Number Maximum Average Number Maximum Average uc/kg uc/kg uc/kg uc/kg 100-B to 100-D 5 110 47 0 - - 100-H to 100-F 5 9 5 2 44 30 Hanford 7 33 15 3 30 24 300 Area 2 1.4 1.3 0 - - N. Slope of Rattlesnake* 10 270 87 12 300 160 200 N 1 9 9 0 - - Benton City to Prosser 4 26 12 0 - - *Includes specimens from Benson and Snively Ranches and from Rattlesnake Springs. Seven mallard ducks from Lacrosse and one from Kennewick were also assayed. - 65 - HW-17381 The highest levels detected were from specimens collected about three weeks following the dissolving. Since 4 uc/kg approximates the tolerance for I131 in tissue, it may be concluded that nearly every specimen of wildlife within the project boundary will have received in December and January thyroid irradiation varying from tolerance to 80 times tolerance daily. - 66 - HW-17381 I. Discussion The weather conditions at the time chose for this run were rather poor in that the atmosphere was unstable and winds shifted direction badly. Probably the most significant information in evaluating the results is the radio sound measurements made at Richland from these plots, it may be seen that in spite of the inversions occurring close to the ground, the upper atmosphere was very unstable with a lapse rate approaching the dry antibatic rate during the period of evolution. Under these conditions, it is difficult to compare the actual results with the theoretical values of Sutton's since the gases were emitted into an inversion close to the ground with some or all of the fumes escaping into the unstable upper atmosphere. For purposes of comparison, we have chosen to consider the dilution as occurring according to the efficient quoted for the large lapse condition. Establishment of theoretical values of the concentration at any given location at a given time is made difficult by the shifting wind directions and speeds and the failure of the sampling technique to give a good I-131 evolution curve. An examination of the wind data indicates that the early portion of the fumes would travel east and north. Somewhat between 0100 and 0400 on 12/3 the wind shifted so that the fumes would tend in a more southerly direction toward Richland. The evolution curves indicate that the xenon peaked at about 2200-0300 on 12/3 while the bulk of the iodine traveled in a southerly direction after 0300-0400 on 12/3. The speeds varied widely from 10-20 mph at the start to 1-5 mph at 12/3. Since the data is inadequate to estimate the travel on an hour to hour basis, an average speed of 6-7 mph was chosen. The scrubber, constant air monitor, and counting rate meter data indicate that the I-131 passed over the 300 Area, Richland, - 67 - HW-17381 Benton City area on 12/3 with the maximum about noon. Wind speeds near the ground at this time near Richland were 5-7 mph with speeds as low as 1-2 mph at the 622 Building. This activity, then, could have been that from the end of the dissolving between about 044 and 0800 on 12/3. The best concentration data obtained in this region were from the scrubber taken from 1200-1400 on 12/3 and the constant air monitor at 300 Area. These instruments indicated concentrations of 1.6 - 3.5 x 10 -7 uc/1 on the scruber and a maximum three hour concentration of 10-6 uc/1 at 300 Area. The factor of three difference in these readings is probably due to the differences in calibrations of the two instruments. The values are a factor of 2-5 lower than would be estimated from the Sutton equations for an evolution rate of 0.05 curies/sec and a wind velocity of 5 mph with unstable air conditions. This would appear to be an adequate check considering the lack of information on the location of the axis of the cloud and the unknown form of dilution. The plot of the conductivity from the aerial survey on the morning of 12/3 shows two peaks, one close to the project between Richland and Connell and the other at Ritzville. Two suppositions may be advanced concerning these peaks. (1) The "highs" represent the two peak output concentrations of gases from the dissolving operation. The one farthest from the reservation could well be the Xe-133 while the I-1331 is just leaving the project. (2) Assuming that the above is true, the gentle shift of winds from the northwest and west to southerly and northeasterly caused the iodine to veer to the north during the morning and afternoon of 3 December, depositing contamination found on the vegetation near Odessa. These theories are substantiated by the following facts: (1) The peak farthest from Hanford during the morning is approximately 70 miles from the dissolving stack. These readings were made from 0915 to 0840 hours - 68 - HW-17381 or at a mean time of 0827. A mean wind of 6.5 from the WSW would place this peak at the stack at approximately 2148 hours on the 2nd which is reasonably close to the true value. The iodine peak was estimated to be at 0200 on the 3rd. For a rough estimate, the same wind speed can be used to place the iodine maximum at 33 miles from the stack at measuring time (0700 3 December). This checks with the position of the second "high" on the morning flight. (2) No I-133 was found on the filters east of the flight between Lind and Riparie. This could be the boundary between the two highly concentrated clouds. (3) Movement of both of these "highs" northward simultaneously would place the xenon at Davenport and deposti the iodine near Odessa. Therefore, if no iodine was present to any extent east of Lind, the scrubber had to collect what it did on the Richland, Lind, Riparia, Lind, Odessa survey. In this case the amount of airflow through the scrubber could be reduced by a factor of 2-2.5 and the iodine concentration raised by the same factor and falls in line with the figures obtained from the filters. If we can rely on the agreement of the two methods of samplying, (filters and scrubber) then an approximate calibration for the conductivity appar atus can be made. On page 48, the flight legs between Connell-Lind-Riparia, where the iodine was detected, show a mean value of 12 divisions above background for the conductivity. Assuming that 1/3 of the roading (or 4 divisions) was caused by the radioactive iodine, we have: 1.4 x 10-8 = 0.35 x 10-8 4 or 3.5 x 10-9 uc/liter/div from this value, the highest concentration encountered on the two-day operation was 1 x 10-7 uc/liter at Davenport (100 miles). According to Sutton's estimate of this concentration with an estimated evaluation rate at the peak of 0.6-1.5 curies/second and a large lapse condition, the concentration should be on the order of 1-2 x 10-6 uc/1, a value 10-20 times the one obtained. - 69 - HW-17381 Considering the number of assumptions involved in the calculation and the calibration of the equipment, this could be considered within the error of the measurement. The above calibration is correct to the order of magnitude only but serves to show the increase in sensititivy of the vibrating condenser monitron over the electrometer tube circuit for which F. J. Davis gives sensitivity of between 10-8 and 10-7 uc/liter/division. The large deposition on vegetation to the south of the stack, then, undoubtedly occurred from the gases leaving the stack after 0200-0400 on 12/3. An interesting comparison with the theoretical values may be comparing the Sutton values to the air concentrations from the deposition rates estimated in Section VIII. If we assume that the average exposure time in the 100-500 muc/kg region between Kiona and The Dallas was 20 hours, then the concentration must have been 1-5 x 10-8 uc/a. Sutton's values for a large lapse condition would indicate 5 x 10-8 to 3 x 10-7 uc/1, assuming a wind speed of 5.5 mph and an evolutation rate of 0.05 curies/sec. Although no conclusive statements as to the validity of Sutton's treatment when applied to these distances may be made because of the uncertainties in the meteorological constants involved, it does appear that the coefficients as used give reasonable values if the primary assumption that the gases diluted in the unstable upper atmosphere is correct. From experience gained from this test, two facts are evident concerning use of the aircraft for tracking such activities: (1). If at all possible, a running plot should be kept in flight to determin regions of highest activity while in flight. Knowledge of the existence of areas of concentrated activity is of little use when the information is brought to light days after the data is taken. Values plotted every thirty or forty minutes (or at lesser time intervals if required) with bacground subtracted will enable the operator to sketch in lines of equal intensity and furnish the pilot with a flight patch which would either remain in the concentration for a longer sampling period or find even higher values. - 70 - HW-17381 (2). The services of two or more aircraft could greatly increase the amount of monitoring coverage for a given period of time. Working as a team at the same or different altitudes, the progress of a cloud could be traced both laterally and vertically. During this run the aircraft surveyed an area in one day which took two weeks to cover by surface vehicles. The degree of accuracy was very close. Under the worst possible meteorological conditions for such a test, the airborne instruments detected the radioactive gases at a distance better than 100 miles from the stack. Under favorable conditions, it was estimtaed that with the same concentrations this distance could have been increased by up to a factor of ten.