Cover Sheet for a Hanford Historical Document Released for Public Availability

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Cover Sheet for a Hanford Historical Document Released for Public Availability"

Transcription

1 Cover Sheet for a Hanford Historical Document Released for Public Availability Released 1995 Prepared for the US Department of Energy under Contract DEAC0676Rt Pacific Northwest Laboratory Operated for the US Department of Energy by Battelle Memorial Institute

2 DlSCLAIMER Portions of this document may be illegible in electronic image products Images are produced from the best available original document

3 * ' HW30999 I '; 6 $\ TECHNOLOGY H A N F I N A L REPORT PRODUCTION TEST RECOVERY OF AMERICIUM BY G V P A C K E R P L ;' ' I TECHNICAL SECTION E N G I N E E R I N G DEPARTMENT 0 3 t o z r: M A R C H 2,1964 t HANFORD ATOMIC PRODUCTS OPERATION RICH L A N D W A S H I N G T O N

4 HW30999 Technology Hanford Processes FINAL REPORT PRODUCTION TEST RECOVERY O F AMERICIUM ~~ G V Packer Plant P r o ces ses Unit Se par at ions Te chnology SubSe ction March 2, 1954 HANFORD ATOMIC PRODUCTS OPERATION RICHLAND, WASHINGTON Operated for the Atomic Energy Commission by the General Electric Company under Contract # W31109Eng52

5 2 HW Technology Hanford Processes I: INTERNAL DISTRIBUTION COPY NUMBER 1 0 H Greager W I( Woods 2 A B Greninger 3 F W Albaugh 4 V R Cooper 5 0 F, Hill 6 W H Reas 7 A E Smith G V Packer 8 E R Irish 9 I? W Woodfield 10 W N Mobley 0 F Beaulieu 11 L M Knights J W Jordan 12 J E Maider T W Hauff 13 C A Priode 14 R S, Bell V R Chapman 15 C T Groswith 16 H A Moulthrop L M Meeker 17 V D Donihee 18 A H Bushev H R Schmidt " File 20 Yellow Copy EXTERNAL DISTRIBUTION COPY NUMBER 21 Armed F o r c e s S p e c A Weapons Project, W Atomic Energy Commission, Washington 24 Chicago Patent Group dupont Company, Augusta 29 dupont Company, Wilmington 30 Hanford Operations Office 31 Hailford Operations Office: Attn J I Knolls Atomic Power Laboratory 35 Patent Branch I W a shingt on 36 U SAF He adqu a r t er s Technical Information Service, Oak Ridge ~,:,e

6 81L 3 HW30999 FINAL REPORT PRODUCTION TEST RECOVERY O F AMERICIUM I INTRODUCTION In response to the need for isolating small quantities of americium for employment in r e s e a r c h studies, principally at laboratories not connected with the Hanford Atomic Products Operation, a y o g r a m was formulated (I) (2) to accomplish this a t minimum cost and disturbance to plutonium production, This report describes the operatims employed and the results obtained in the isolation of americium from aged plutonium nitrate solution utilizing the Isolation Building process equipment 11 OBJECTIVE The objective of the production test was to establish a process for isolating americium from aged plutonium using existing equipment ID SUMMARY A method for isolating Am241 from a mixture of plutonium isotopes using a peroxide precipitation nearly identical to that used to separate plutonium from lanthanum was developed for use in Hanford Atomic Products 'I Oileration plant equipment A total of 98 milligrams of Am241 w e r e isolated from about 1600 g r a m s ~f aged p!ii:on!uix (as plztoniun nitrate) and YO50 milligrams of Am241 were isolated from about 6 4 Kg of aged plutonium (as metal scrap) using the isolation building equipment Based on radiochemical analyses the yield ranged from 92 to 104 per cent The use of filter sticks to separate plutonium peroxide from the supernatant gives an acceptable concentration in the supernatant without further concentratim When the w a s h solution is added to the content is increased slightly, however, the supernatant the total concentration is reduced excessively, it ~

7 4 HW30999 lv EXPERIMENTAL The r a w material for this production test was about 1600 grams of plutonium a s dried plutonium nitrate aged 079 y e a r s to 106 y e a r s and 6400 grams of plutonium a s metal s c r a p accumulated in storage between 1949 and 1953 The concentrated and aged plutonium nitrate was flushed from the sample cans and processed in two can batches through a plutonium peroxide precipitation in the second cycxe precipitator tank The supernatant solution (including the wash supernatant) containing the Am241 w a s transferred to the supernatant collection tank where the excess hydrogen peroxide was thermally decomposed The supernatant solutions of the 079 year aged plutonium were transferred to a glass lined evaporator in the Purification Building, concentrated from 91 to 13 l i t e r s and loaded into the shipping containers Americium was isolated from the 106 year aged plutonium in the s a m e manner except that the supernatant solution was not concentrated since it could be contained in the shipping vessel The plutonium portions (peroxide cakes) were processed through the treatment which follows the normal second peroxide cycle, j j j i 1I i The excess metal from samples taken in the fabrication building has been stored since 1949 pending recovery of the plutonium In the spring of 1953 an americium recovery program w a s incorporated with the' recovery of this aged metal using the plutonium peroxide precipitation process The feed solution was prepared by dissolving the plutonium metel in hot nitric acid (?O PPI cent) and hydrufluoric acid (002X) and diluting with distilled water to the desired hydrogenion concentration (2 OM) Instead of decanting off the supernatant solution, the peroxide s l u r r y was filtered through the sintered stainless steel filters, which facilitated the removal of a greater volume fraction of solution from the cake than was possible by decanting

8 , _:_, 5:;y & i Z' It was advantageous, for this reason, to collect only the original americium rich filtrate and exclude the wash filtrate solution, thereby eliminating 241 the need for concentration of the solution containing the Am V DISCUSSION The extent of the batch recovery of americium from plutonium depends primarily upon the mechanical ability to transfer the solutions from one v e s s e l t o another without holdup and upon thorough washing of the plutonium peroxide precipitate within chemical conditions compatible with low plutonium l o s s e s t o the supernatant solution The problem of solution holdup was solved by following each transfer with flushes employing dilute nitric acid It is not practical to remove all of the soluble americium by copiously washing the plutoaium peroxide cake since this would dilute the americium excessively and result in solution volumes g r e a t e r than those which can be economically concentrated Based upon the relative solubility of the americium and the d e s i r e to keep the plutonium concentration and final combined supernatant volume low the normal t h r e e washes of plutonium peroxide cake ( 5 0 Kg each of 60 per cent nitric acid) w e r e used for the first Am241 isolation runs The combined supernatantwash solution w a s concentiated in a glass lined evaporator A s u m m a r y of the Am241 isolation and concentration f r o m the first eight cans (aged 079 years) of material processed is given in Tables I and The analytical r e s u l t s of these runs are presented in Tables III and IV? I to show the typical solution eorrcentraticrna and signincant impurities Additional Am241 w a s isolated from two sample cans of material aged y e a r s The americiuma4' bearing supernatant solution was not concentrated because the solution volume w a s l e s s than the capacity of the shipping container This run is summarized in Table V,:, 2 :& <+ *, ;4 <;:?$? :,? :%,?% *ex : :z'a,,,,'~ LO? 1

9 EI HW Twenty typical americium byproduct runs made during the 1953 plutonium recovery program are listed in Table VIII These returned 64Kg of plutonium to the process and recovered 005% grams of A m (81 per cent yield of the Am241 radiochemicaliy determined to be in the starting solutions) The amounts of Am241 indicated in Tables I and V approrimated the amounts which w e r e calculated to be present based on the age of the plutonium arid the pile exposure history of the original uranium metal W h e n uranium is discharged f r o m a Hanford pile it contains some of the isotope Pu241 which is formed by a combination of nuclear reactions during the pile exposure The amount is related t o the MWD/T as shown in Figure I 721utro11ixn241 (142 y e a r halflife) decays to A m by emitting a betaparticle Thus when the uranium metal is s t o r e d days before it is processed for plutonium isolation, 1 13 per cent is removed w i t h the of the Pu241 decays The daughter isotope waste and fission product solutions of the separations process, therefore, the plutonium that w a s s e t aside for this production t e s t initially contained about 9 9 p e r cent of the Pu241 present in the uranium metal at the time of pile discharge Figure 11 shows the relationship of Ama4' growth per g r a m of Pu241(present at start of aging) to the age of the plutonium since the last chemical separation, based on the halflives 142 and 470 y e a r s of pu241 and Amz4', respectively '

10 7 Calculating the amount of Am 241 present in aged plutonium is illustrated below for the first run (see Tables I, IIf, and VI): Amount of plutonium in starting solution Pile exposure of original uranium Ratio: (from Figure I) 2 41 Amount of Pu Age of plutonium since last chemical separation Ratio: Am241/pU241 (from Figure II) Caiculated amowit of Am 241 Amount of Am241 in the starting scllution by 1adiochemicai assay 348 g r a m s 394 MWD/Ton g r a m s l g r a m 079 years = 95 mon 0038 grams/gram 0,038x0466x1000 =I?, 207 m g The actual amounts of Am241 are compared to the calculated a m in Table VI The actual values were used to backcalculate Pu weight r a t i o s for comparison t o the curve of Figure I The P u ratio for the first run based on the Am241 radiochemically determined to be the starting solution was computed as shown below: 079 years f 95 mo Age of process starting solution 0038 gramslgram Ratio: Am241/Pu241 (from Mgure II) mg = g m s Amount of Am241 in the s t a r t i n g solution Amount of P u241 hmnrint n t r nliitqciim fi, I"& at,mf&g fi~luaon Ratio: Pua4'/Pu File exposure of original u r d u m Ratio: Pu241 /Pu (from Figure I) 0020?~0,038= oqame 05&/348 = gr 394 m / t m These and the calculations for the other four runs are given in Table v 11 W & G V Packer GVP:ms

11 8 HW30999 VI REFERENCES I HW16038, "Americium Separation from Plant Solutionsu, 0 F Hill to F W Albaugh, February 15, 1950, 2 HW17518, "Discussions on Americium Processesn, M J SzulinSki and G V Packer to File, April 13, HW2 91 I 9, "Laboratory Study of Americium Recovery Processes, C F, Callis to File, October 1, mv17990, "Production Test Recovery of Americiumm, M Szulinski t o File, June 2, HW26584, mtheisotopic Content and Specific Activity of m e Produced Plutoniumw, by E M Kinderman, H R Schmidt G J Alkire, A, ChethamStrode, androy KO, January 12, 1953

12 TABLE I AMERICIUM MATERIAL BALANCE, ISOLATION BUILDING Am241 Total Weight, Metal Aged Original+Wash History Starting Supernatant Run No MWD/Ton Solution Solution ,394 Total ,? (1) The final combined solution of mg Concentrated M a t e r i a l Plutonium Balance Cake Solution Per Cent 3, OC! m Am241 Lost In Cake Solution, Isolate, P e r Cent Per Cent 12' T33 contained approximately 3 grams of plutonium TAnLE II AMERICIUM MATERIAL BALANCE, PURIFICATION BUILDING Input, mgbefore Concentration (Combined analysis) 761 After Concentration (for offsite) After Concentration (for onsite) Total Material Balance, Per cent I9 Unaccounted for loss, Per cent _ output, mg TTT

13 HW TABLE I11 AMERICIUM RECOVERY ANALYTICAL RESULTS, ISOLATION BUILDING FIRST EIGHT SAMPLE CANS Am, g x Starting Pu, 4542 Solution H, g Fe, g/ Sp Gr 1112 Volume, l i t e r s x 196 x 3778 I x Run No fh "/' Supernatant Am* Pu, g 1 Solution(l) Fe, g/1 Sp Gr Volume, l i t e r s x Concentrated Am, g / l x Plutonium Pu, g/ Cake Fe, g/ Solution Sp Gr 1673 Volume, l i t e r s x ?L x (1) The supernatant solutions of runs 1 and 2 were combined and sampled; likewise, the supernatant solutions of runs 3 and 4 were combined and sampled

14 11;G& TABLE IV % AhlERICIUM RECOVERY ANALYTICAL RESULTS, PURIFICATION BUILDm6' =?: 54 FIRST EJGHT SAMPLE CANS 3 * s 1 :$ Combined Supernatant Solution SB e for e Con c ent r at ion) 0836 Sp G r Volume, liters I o SDectrochemical Ca, Cr, La, Na, Ni, ppm of ppm of ppm of ppm of ppm of ' Pu 3 x 10; Pu 5 x lo4 Combined Supernat ant Solution (After Concentration) C he mi c a1 Am,g/J Pu, g l l Fe, gfl Pu 2 x lo3 Pu 5 x l o 3 Sp Gr Pu 1 x 10 Volume, liters

15 $, 0 i 1 TABLE V AMERIC1UM MATERIAL BALANCE, ISOLATION BUILDING Am241 'Lost 241 Total Weight, m Metal OriginakWash Conceni sate Material In Cake Am Balance Solution, Isolated aistory Starting Supernatant Plutonium MWD/Ton Solution Solution Cake Sclution Per Cent Per Cent Per Cent g a_ Run No $ T A B L E VI AM241 CALCULATED TOBE IN TKE STARTING SOLUTIONS L MWD/Ton =, grams P u ~ ~ ~ / P u (Pu241J ') Wt Ratio grams (1) Obtained frcm Figure I (2) 0btainedfrom Figure ' Age, months Wt a w N I

16 TABLE VI1 PI,UTONIUM241 CONTENT O F PLUTONXUM DERIVED FROM PILE IRRADIATED URANIUM AT THE TIME OF LAST CHEMICAL SEPARATION A g e of Process Starting Run Solution No Months Wt,&itio 241 Am /Pu from Figure Am241 in Process Starting Solution, Grams pu241 Present At Start of , Aging Total Pu Isotopes In Process Starting Solution, g m s BackFig I calculated WtZ4fiatio W34Patio MWD/ Pu /pu Pu / P u Ton (Ref 5) I c1 w I

17 1953 Run No 0 (2) Z535Z Z Z z 5 3 o 5 z 2 a Total, 20 runs (3) (4) (5) a _ (6) (7) , (1) Starting solution volume, liters (2) (3) (4) (5) (6) (7) (8) (9) fl Starting solution grams Starting solution A r n S i i total mg (radiochemkal andyafa) Starting solution Am total mg (calculated from history data) Peroxide supernatant solution volume, liters Peroxide supernatant solution Pu grams Peroxide supernatant solution Am total mg Peroxide supernatant solution p e r cent P u Peroxide supernatant solution per cent Am recovered Wl Mt

18 FIGURE I PLUTONIUM241 CONTENT O F PLUTONIUM DERIVED FROM PILEIRRADIATED URANIUM A T T H E TIME O F LAST CHEMICAL SEPARATION ! NOTES 1 C u r v e i s b a s e d o n data i n r e f e r e n c e ( 5 ) 2 Values taken f r o m Table V I I 0 3 S i n c e the last c h e m i c a l s e p a r a t i o n o c c u r r e d d a y s a f t e r p i l e d i s c h a r g e, t h e Pu241/ P u r a t i o h e r e i s about 99 p e r c e n t of the r a t i o a t t i m e of d i s c h a r g e I MWDITON

19 16 FIGURE I1 GRAhIS OF AMERICIUM241 A F T E R AGING A S S X I A T E D WITH O N S GRAM O F PLUTONiUM241 AT S T A R T OF AGING ' z 4; c: * NOTES 002 i halflife = years halflife = 470 years