Plans and Hazards Analysis for the First Hanford Iodine-131 Field Release Test (Cover Sheet Route Slip)

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HANFORD ATOMIC PRODUCTS OPERATION - RICHLAND.WASHINGTON I SIGNATURE AND DAT EF I LES ROUTE TO BE USED ON UNCLASSIFIED AND OFFICIAL USE ONLY DOCUMENTS.

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PLANS AND I S ANALYSIS FOR THE FIRST HANFORD I13l FIELD RELEASE TEST Physics and Instruments Laboratory RICH LAND. WASHINGTON This report was prepared for use within General Electric Company in the course of work under Atomic Energy Commission Contract AT(45-1) - 1350, and any views or opinions exprersed in the report ore those of the author only. This report i s subject to revision upon collection of additional data. This report was prepared as an account of Government sponsored work. Neither the United Stoles, nor the Commission, nor any person acting on beholf of ihe Commission: Makes any warranty or representation, expressed or implied, with respect to the accuracy, conipleteness, or usefulness of the information contoined in this report, or that the use of any information, apparotus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes a r j liabilities with respect to the use of, or for damoges resulting from the use of any information, apparatus, method, or process disclosed in this report. As used i 4 the above, “person acting on beholf of the Commission” includes any employee or contractor of the commission, or employee of such controctor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepores, disseminates, or provides access to, any information pursuant to his employment or contract with the Commission, or his ernploynient with

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PLANS AND HAZARDS ANALYSIS FOR THE FIRST HANFORD 1131 FIELD RELEASE TEST The determination of the dispersion and subsequent behavior o f 1'3' released tothe atmosphere i s important inthe determination of the possible hazards which can exist as the result of releases of significant quantities of iodine from atmospheric bomb testing or from accidental releases from nuclear establishments. I Hanford Laboratories has long been involved in investigation of 1131 as part of the Environmental Monitoring, Biological and Chemical Laboratory i n g personnel from Radioecology, Atmospheric Physics, Radiological Chemistry, Chemical Effluents Technology, Environmental Studies and Evaluation, and diffusion grid operated by At.mospheric Physics personnel. tai ned from this experiment with carefully selected meteorological conditions should provide increased understanding of the details of the interac - tions involved that cannot be separated i n observations made during the varying conditions encountered when fallout or nuclear plant produced iodine i s present inthe atmosphere. This planned experiment isa cooperative endeavor util iz - Experiment will be conducted on the atmospheric The following sections give plans for the experiment and estimates of the expected results. tion and Operational Procedure. The appendix contains the makeup ofthe Test Organiza-

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The Hanford Stable Grid is located near the Meteorology Tower near and 12800 meters distant from the source release point. Samplers are located along arcs 200, 800, 1600, 3200, The four innermost arcs are each equipped with five towers t o enable the vertical distribution t o be measured also. "he experiment will be conducted during moderately stable night-time conditions with surface wind speeds inthe range from 0.5 to3 meters/sec. Two 150 rnc sources have been ordered from Oak Ridge for delivery at Hanford on July 22. Each source will consist of 10-15 mg of elemental iodine sealed ina two-inch long glass ampoule 8 am outside diameter. A direct calibration will be performed with a lar-geometry gamma counter which has been calibrated for 1131. Accuracy expected i s canservat iv ely + 5 percent. into the release fixture and shield. After calibration each source ampoule will be loaded The release fixture consists of two l/h-inch stainless steel ball valves joined by a short length of 9/16-inch thin-wall stainless steel tubing. A nipple for am air supply and an outlet nipple are provided. release fixture i s mounted in a lead shield consisting of two 2" x 4" X 8" lead bricks milled out t o receive the ball-valve assembly. The shield will be placed in a plastic bag and mounted at a suitable elevation with the outlet nipple pointing downwind. An air hose will be

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connected tothe inlet nipple. (Air o r helium will be used t o sublime the iodine. ) The gas t o be used w i l l be passed through a rotameter and membrane filter before entering the ball-valve assembly. release, the ball valves will be opened and the release gas adjusted tothe On signal to start the The 9/16" thin wall tube will be compressed with the 1/2" bolt and pressure foot t o crush the ampoule. The release will proceed until the iodine is exhausted from the tube. During release the source will be monitored by a recording count rate meter which is fed by a GMtube located i n Any residual iodine will be washed from the assembly and an ali quo t of the washings assayed for 1131. The second source will be standby i n case additional iodine-131 is needed due t o delay or other causes. If not used in the test, it will be used as a cross check of the calibration. Special air samplers each consisting of a membrane filter backed up by a four-inch thick bed of silver plated copper turnings, a charcoal impregnated filter paper and a 1.5-inch bed of activated charcoal will be operated at 608 locations in the sampling grid. provides the capability to identify the fractions of 1131 associated with particulate, elemental iodine and other possible chemical forms which might This sampler design be formed after release from the source. A few other air samplers will be operated in the field after the experiment to detect any release of iodine from contaminated soil and vegetation.

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Vegetation and Soil Sampling Seven vegetation plots measuring 5 by 20 feet have been placed end t o end along the 200-meter arc of the field grid. and a pasture mixture of various grasses. Each plot is planted with rye This arrangement of vegetative cover is designed t o simulate an irrigated farming area. width will be narrow at this distance and because of limited sample counting facilities only three plots of the seven will be used for sampling and The sampling program is designed t o provide data on (a)the biological decay rate of atmospheric 1131 deposited on standing plant material, (b) the degree of stratification of deposited I13l throughout the vegetative layer, deposition on wet and dry soil. plant morphology, different plant species and art if i cli al plants will be used t o determine i f various materials have similar or different affinities for atmospheric Il3l. Three uniformly contaminated plots will be selected for sampling immedi at ely following release. Five samples will be taken from each plot on the dates shown in the table. plastic containers and stored in a refrigerator until they can be counted. Green plant materials will be placed i n 500 ml 1, 2,3, 4, 5,8 Total rye plant to study biological 1, 4 Rye plants cut at 5different heights t o 150 1, 2, 4, 8 Harvest low growing plants(plant stature) 60 1, 4, 8 S o i l samples (wet and dry) 50 determine stratification of deposited 1131.

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Type of Sample Deposition on sage brush vs. plant canopy 1, 2, 4, a, 16 Cheat g r a s s upwind, downwind. Samples t o determine total deposition on vegetable and soil. Effectiveness of various washing solution t o remove 1131 from leaves. In addition to these special plots at the 200 meter arc other vegetation such as cheat grass and sage brush and soil samples will be obtained at various locations near air samplers for determining deposition velocity at various other distances. There will also be an attempt t o measure vegetation contamination a t the plant boundaries and while calculations indicate this might be possible the presence of other Il3’ from normal plant emissions could easily obscure the experimental plume deposits at such distances. The experimental vegetation plots are too small to allow for measurements of uptake i n grazing animals but there will be a measure of thyroid uptake due to in hal at ign ’ in three experimental dogs which will be placed on the 200 meter Detailed predictions of the finer structure of the expected distribution cannot, of course, be made at this time. Observations of atmospheric behavior

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such as the extent of the inversion, wind fluctuations in speed and direction will be made cont.inuously both before and during the actual release. the release is completed these data will be used to predict in detail the shape and magnitude of the expected distribution and will be used i n programming the cr der of p;ckup of the various samples t o minimize chances of cross Using experience Gbtained from previous test runs made with releases of fluorescent pigments during similar weather conditions the is ople th s of expected exposures within the experimental grid have been estimated and are given i n Figure 1. The estimates of exposure are given in units of milli - curie seconds per m3, collected on the silver plated copper. largely on the charcoal with only minimal amounts associated with part icu - lateE inthe membrane filter. Vegetation and Soil "he major portion o f t h e iodine, about 80$, should be The remainder i s expected t o be Separate is ople th s for the expected ground and vegetation contamination have not, been constructed but can be obtained by multiplying the exposure values by 0,007 ( a deposition velocity of 0.7 cm/sec). The determination of the fr act lo nation of this total deposit between the ground and the vegetar.ic.nwill vary considerably, being largely on vegetation where the vegetation cover is faf rly thick and correspondingly less where the cover is thin. Animal Thyroids- 5The beagle dogs are expected t o breathe ata rate of about 8 x 10m3/sec and t.he deposition i n t,he thyroid to amount t o l5$ of the amount t o be lf4c sez/m3, the maximum thyroid burden inthe dogs i s expected t o Since the center line exposure atthe 200 meter arc i s expected

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or 1.2 nc, a quantity which should be measurable. The expected airborne exposures t o iodine (Fig. I) are based on an assumed release of 0,l curies with a wind speed of 1.3 m/sec. For purposes of estimating hazards it i s desirableto assume somewhat more pessimistic conditions. Since the source may contain more than the quantity ordered, the source strength will be assumed t o be 0.15 curies. The wind speed during the release might be a factor of three less than previously assumed so that the possible exposures could be approximately five times higher than ing rate fora standard man as 3.47 x m3/sec and an uptake inthe thyroid of 0.23, the possible thyroid burdens o f men exposed along the Using these higher exposure values and assuming the breathcenter line of the plume have been calculated and are given inthe followThe point of nearest approach tothe experiment site for persons not connected with the experiment isthe road which runs north and south between the Meteorology site and 200 West and this is about 800 meters from the release point and i n what i s expected t o be the upwind direction. The possible thyroid burden at this distance is only 4 nc and could occur Only i f there were a complete reversal in wind direction. The continuous per-

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missible thyroid burden for occupational exposures is given b y the I C R P as even if it did occur. So this highly unlikely exposure could not be considered hazardous

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Test Control Group The following persons will comprise the "est Control Group atthe * Chairman ofthe Control Group during test. (@onset Hut) approximately 1000 feet west of the Meteorology Tower. All personnel will sign the log at this point and change to field clothing as prescribed by RMO. NO private cars will be permitted beyond this RMO check station. can be made from 6 2 2 - ~with t h e Test Conductor a t 6 2 2 - ~for admission beyond this point. Vehicular traffic beyond this point will be controlled. Except for the source, all equipment will be i n place by T-10 hours. Entry to grid area arter this time will be for equipment startup or plating perishable samplers in the field except as approved by the Technical

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OPERATIONAL PROCEDURE - WORD IODINE RELEASE - 1963 Tentatively, the plans areto begin a release of iodine at 0200 F". The following count-dawn may be adjusted by "holding" o r "jumping" t h e count. All times refer to Pacific Daylight Time. Simpson will obtain tentative forecast. forecast is favorable, Hungate and Ludwick will be informed Inthe event the Background values from above will be phoned toC. L. Simpson (2-7778, 2-7716 ). Updated forecast obtained. Conference call between APO and C.C. Camertsfelder t o reach decision on Inthe event of a decision to go, APO notifies all group representatives as follows: Forecast obtained by Simpson. and proceeds t o Laboratory. Cline takes background sample log. APO field personnel be prepared t o begin work at this time; stand-by at Hut for signal to dispatch to field. are responsible f o r checking out through RMO and Test Conductor on activities that carry them from their assembly point. Cline notifies S hp son via phone the results of background Start mast and B&W equipment. APO directed to field, begin starting engines. Source source reported t o Simpson. Report of arrival of ..___NOTE: A t T-1.0 Hr., all people except those directly concerned with the release will not be permitted inthe area around the source and between the source and the 200 meter arc. will follow existing arc roads. All traffic from the field

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Cline waters dirt samples, dogs in field, Rising adjusts chamber at 200 meters. Start a r c 3 mast, wind component meter. All personnel in field return to hutment and login. Control group assembles at 6 2 2 - ~ . RMO notifies Simpson that all personriel are accounted for Iodine release, tower equipment on speed run. Source returned to 200-W - Call (2-7778) (2-7716) on c m p l e - APO personnel t o 200 meter arc to pick up all samples (ground and tower) on RMO approval. Monitors t o 800 meter arc. APO personnel t o 800 meter arc to pick up all samples on RMO RMO personnel t o 1600 meter arc,all meteorological support instruments at source returned t o slow speeds. Cline t o sample vegetation, Ludwick t o sample vegetation on advice of RPO, Rising also to 200 meters. APO personnel t o 1600 meter arc to collect samples on RMO Cline begin plant stature studies.

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RMO t o 3200 meter arc. APO personnel t o 3200 meter a r c on approval of …