- Email: [email protected]
I.A.E.A. seminar on the practical applications of short-lived radioisotopes produced in small research reactors
KEPORT I.A.E.A. OF
OF MEETING
SEMINAR ON ‘I‘HE PRAC’I’ICAL AI’PL1CA7’10NS SHORT-LIVED RADIOISOTOPES PRODUCED IN SMALL RESEARCH REAC’I’ORS \-ic,rrlln.
5-!) .So\,c~n!,~,r
lO(jl)
I.A.E.A.
seminar on short-liaed ,-adioisotoi,es
i.e. complete apparatus for a given chemical proThis would promote the use of radioisotopes cedure. with still shorter half-lives than in common use at the present. The Scottish Reactor Centre was described in another paper, where projects involving short-lived radioisotopes were also outlined (A. WARD-U.K.). The production programme and some details for the production procedures for short-lived radioisotopes at the Hahn-Mcitner Institut was also reviewed (F. E‘Er.Is-Federal Republic of Grrmanyj. Br-82 is a tracer used widely in industry; expericnces with the irradiation of ammonium bromide were presented (K. HEYDoRNPl>cnmark). In some cases irradiation cans had ruptured and therefore the radiation decomposition of ammonium bromide had been studied under different conditions. It had for instance.. been found that hydrogen formation varied linearly with the total dose up to several thousand Afrad. In t\co papers, the production of .I‘c- 132 and I- 132 by cstractiotl from irradiated uranium \vas described (B. S.rrttNNoN-BovY-Bclgilml and AI. BARRACFWVAGox*I
333
short-lived tracers: studies of the transport of solids; determination of residence timr hold-back and blocked volume in reaction vessels; mapping of flow in receivers for sewage or waste water; flow-rate tagging for identification purposes; measurcmcnts; “weighing” ; studies of non-metallic inclusions and surface defects. Many of these investigations are not yet made on a routine basis, and in the discussion the question was raised whether the tcchniqurs will be devclopcd for routine use. This is being studied by sex-cral groups and it was pointed out that small reactors: situated in heavily industrialized areas, as lvcll as nrtltron gcncrators, radioactivr nrutron for tracer sources, and “COUX” have potentialities production. Scvcral of thr applications mrntioned above \vvcrc illustrated in othrr paprrs, presenting specific uses in difxcrent branches of industry. Process units have been studied for rvaluation of the details in their performance. In the lightweight concrete industry, powder-mixing studies were Wportcd (13. G. l’ORSBERc:+SWeden!. In general, racliotraccr tcchniqurs facilitate mixing studies as tedious anal>-tical procedures can be replaced by rapid activity mCasurcmcnts. It Teas emphasized that a statistical trcntmrnt of the activity data enables an accurate dctrrmination of the optimum mixing time in batctl mixers to be made. This \vas illustrntcd by results from investigations of three difliirent designs of concrctc mixers. 0ther types of process units in the chemical industry have also bcrn investigated. In gas-liquid reactors the \.olume of the liquid as well as the liquid flow rate undrr different conditions havr been measurcxl: in the latter case labclled polypropylene balls proved uscablc as “tracers”. klaterial transport has bccm mapped in a rotary kiln usrd for pyrite roasting (K. l’ROIri~r;F~C;crmany). ‘1’11~rcctifjcation process for zinc, by means of distillation, has brcn invrstigatcd in detail (K. .\KI~.llhlAN l'ohntt I. 't‘tlcCOllCCIl~I2tiOns ofimpuritirs will1 clifferrllt boiling points tC:u-(2, Fe-.59 and (M-1 15 I and of zinc (Zn-69m~ 1,rre mrasurrd at variotls points in the column. The rcxults contirmcd the validity of the tticorics for Lllc proc’css but also indicntcd ho\v thr design should bc c.hangcd to givr a bcttrr product. Flow studies and How-rate measurcmcrlts on gases or liquids wcrc rcportcd also in other palxrs iJ. S. \~.\T.I. .\ustralia. G. Cor:~.rors and .J. ~~!IZI:RISFKmCcI. Smaller-scale vclltilation studirs~Pe.g. in houscS Aa\c bran made with Xe-I 33 as a tracer. Largr-scale vc.ntilationP in open air- is studied with Cu-64 as copper oxid<, powder; air samples are filtcrrd and the amount of tracer mcasurrd on tllc filter (\TATT~. ‘This technique offers possibilities for studit of’ air movemrnt in clouds and has also
I.A.E.A.
seminar on short-lived radioisotopes
performed for identification purposes, i.e. comparison between a sample of unknown origin and samples of known origin. In criminology this has potential value and a case was quoted where grease and oil found on a street could be related to a certain car. As this type of identification is assumed to be used as an evidence in court, considerable attention is paid to the accuracy of the identification. It was pointed out that industrial products from different manufacturers show great diffrrcncrs in their “fingerprints” found by activation analysis. This paper provoked the most intensive discussion of the seminar, with several questions about details of the operation of the TRIG11 reactor, including a general discussion about fast rabbits for very shortlived tracer-work, and about specific applications, for instance oxygen determination. ‘Two paprrs dealt with determination of impurities in beryllium (C. ENceL~~AxN-France and C. A. BAKER~~U.K. 1. Non-destructive as well as chemical methods wcrc described. The spectrum-subtraction method was claimed to give an accuracy of 10 per cent. Impurities have been studied in diamonds by (K. Loos -Congoj. means of activation analysis In the same paper the use of autoradiography as an analytical procedure was described. Fast radiochemical mrthods for the determination of impurities in aluminium, zirconium and iron have been developed (I’. ALBEKr-France). The scnsi tivity limits were given for the determination of cprtain impurities by means of instrumental activation analysis. and also for methods in\rolving chemical separations after or before neutron irradiation. Niobium and tantalum have been drtrrmined in ores and wastes (C. K. Kn+Republic of Korea) and sodium in solution and in silica-alumina gels
(I’.
Br;ssn%k.~Francc)
.
Various equipment used in an activation analysis programme was described (D. GIBIXXV+LJ.K.). Several applications were discussed in some detail, e.g. determinations of rubidium, calcium, selenium and cobalt, by means of short-lived isotopes. Formulae have been developed for the evaluation of activity data obtained by means of coincidence techniques (M. A. Dx-Netherlands).
C:ICFPOLOTTI-
Italy,. of strontium Apfllicntions in Of the two production iodine- 132 (H. SORANTIN--:\ustria
in rat papers and
M.
in this .\NBAR-
335
Israel). In the latter, a method for the determination of the rate of thyroxine deiodination in humans was also given. An electrochemical technique has been developed to label albumin and other compounds with Br-82 (U. ROSA-Italy). Formulae were given for the intracellular conThese have centration of sodium and potassium. been tested using tracer methods !K. IT.UIAK.~-
Japan).
metabolic technique (R. four freeze-cutting, P-therapy
autoradiography a frozrn was Republic Germany). freeze-drying, freeze-grinding compared. loaded have used PxRQuxN-Franc?). use
,\Nn.4R--Israel). Studies in bone physiology showed that F-follows calcium. As another examplr, fluoroborate ions were found to accumulate in the thyroid gland. The browning of fruits and vegetables had initiated studies of the mechanism of enzymes, with CL-64 as a tracer (J. C. A2~~~~~~,JR.-U.S..k~. It was found that a dissociable bond exists bctwren the enzyme and copper and gives the enzymatic action of copper oxidase. The isotopic exchange of potassium in an illite had been studied in detail (hf. E. SUMMER -Xetherlands.) This included studies of the influence of other ions, among which NH,+ showed a strong blocking of the entry of K-42 into the lattice. This seminar was the first international gathering dealing with the applications of Jhort-liwd radioisotopes. aZs with all international meetings it scrlretl the exchange of information bet\vcen a dual purpose: sophisticatrd isotope users, and the promotion of thra isotopr applications in less developed industries and countries. The immediate benefits of this seminal srem to apply mainly to the former and from this point of view the semmar must be concludrd to have bern well worth-while. However, the versatility of
336
K@Od
sllort-livccl radioisotopes as tracers and as a tool in activation analysis became obvious from the pa*xw I-cad at the suninar, and the prorrcdings of the wminar shoulcl 1~~11)to svrvc also thv latlcr purposes. It seems highly dcsirablr that cormtrivs with small IxxYwCh rc~aCiors ant1 also. br instancr~. heavilx intl~~strinlizcd arcw in tl!c vicinitv of suc11 rcarwrs
OF MEETING
SEMINAR ON ‘I‘HE PRAC’I’ICAL AI’PL1CA7’10NS SHORT-LIVED RADIOISOTOPES PRODUCED IN SMALL RESEARCH REAC’I’ORS \-ic,rrlln.
5-!) .So\,c~n!,~,r
lO(jl)
I.A.E.A.
seminar on short-liaed ,-adioisotoi,es
i.e. complete apparatus for a given chemical proThis would promote the use of radioisotopes cedure. with still shorter half-lives than in common use at the present. The Scottish Reactor Centre was described in another paper, where projects involving short-lived radioisotopes were also outlined (A. WARD-U.K.). The production programme and some details for the production procedures for short-lived radioisotopes at the Hahn-Mcitner Institut was also reviewed (F. E‘Er.Is-Federal Republic of Grrmanyj. Br-82 is a tracer used widely in industry; expericnces with the irradiation of ammonium bromide were presented (K. HEYDoRNPl>cnmark). In some cases irradiation cans had ruptured and therefore the radiation decomposition of ammonium bromide had been studied under different conditions. It had for instance.. been found that hydrogen formation varied linearly with the total dose up to several thousand Afrad. In t\co papers, the production of .I‘c- 132 and I- 132 by cstractiotl from irradiated uranium \vas described (B. S.rrttNNoN-BovY-Bclgilml and AI. BARRACFWVAGox*I
333
short-lived tracers: studies of the transport of solids; determination of residence timr hold-back and blocked volume in reaction vessels; mapping of flow in receivers for sewage or waste water; flow-rate tagging for identification purposes; measurcmcnts; “weighing” ; studies of non-metallic inclusions and surface defects. Many of these investigations are not yet made on a routine basis, and in the discussion the question was raised whether the tcchniqurs will be devclopcd for routine use. This is being studied by sex-cral groups and it was pointed out that small reactors: situated in heavily industrialized areas, as lvcll as nrtltron gcncrators, radioactivr nrutron for tracer sources, and “COUX” have potentialities production. Scvcral of thr applications mrntioned above \vvcrc illustrated in othrr paprrs, presenting specific uses in difxcrent branches of industry. Process units have been studied for rvaluation of the details in their performance. In the lightweight concrete industry, powder-mixing studies were Wportcd (13. G. l’ORSBERc:+SWeden!. In general, racliotraccr tcchniqurs facilitate mixing studies as tedious anal>-tical procedures can be replaced by rapid activity mCasurcmcnts. It Teas emphasized that a statistical trcntmrnt of the activity data enables an accurate dctrrmination of the optimum mixing time in batctl mixers to be made. This \vas illustrntcd by results from investigations of three difliirent designs of concrctc mixers. 0ther types of process units in the chemical industry have also bcrn investigated. In gas-liquid reactors the \.olume of the liquid as well as the liquid flow rate undrr different conditions havr been measurcxl: in the latter case labclled polypropylene balls proved uscablc as “tracers”. klaterial transport has bccm mapped in a rotary kiln usrd for pyrite roasting (K. l’ROIri~r;F~C;crmany). ‘1’11~rcctifjcation process for zinc, by means of distillation, has brcn invrstigatcd in detail (K. .\KI~.llhlAN l'ohntt I. 't‘tlcCOllCCIl~I2tiOns ofimpuritirs will1 clifferrllt boiling points tC:u-(2, Fe-.59 and (M-1 15 I and of zinc (Zn-69m~ 1,rre mrasurrd at variotls points in the column. The rcxults contirmcd the validity of the tticorics for Lllc proc’css but also indicntcd ho\v thr design should bc c.hangcd to givr a bcttrr product. Flow studies and How-rate measurcmcrlts on gases or liquids wcrc rcportcd also in other palxrs iJ. S. \~.\T.I. .\ustralia. G. Cor:~.rors and .J. ~~!IZI:RISFKmCcI. Smaller-scale vclltilation studirs~Pe.g. in houscS Aa\c bran made with Xe-I 33 as a tracer. Largr-scale vc.ntilationP in open air- is studied with Cu-64 as copper oxid<, powder; air samples are filtcrrd and the amount of tracer mcasurrd on tllc filter (\TATT~. ‘This technique offers possibilities for studit of’ air movemrnt in clouds and has also
I.A.E.A.
seminar on short-lived radioisotopes
performed for identification purposes, i.e. comparison between a sample of unknown origin and samples of known origin. In criminology this has potential value and a case was quoted where grease and oil found on a street could be related to a certain car. As this type of identification is assumed to be used as an evidence in court, considerable attention is paid to the accuracy of the identification. It was pointed out that industrial products from different manufacturers show great diffrrcncrs in their “fingerprints” found by activation analysis. This paper provoked the most intensive discussion of the seminar, with several questions about details of the operation of the TRIG11 reactor, including a general discussion about fast rabbits for very shortlived tracer-work, and about specific applications, for instance oxygen determination. ‘Two paprrs dealt with determination of impurities in beryllium (C. ENceL~~AxN-France and C. A. BAKER~~U.K. 1. Non-destructive as well as chemical methods wcrc described. The spectrum-subtraction method was claimed to give an accuracy of 10 per cent. Impurities have been studied in diamonds by (K. Loos -Congoj. means of activation analysis In the same paper the use of autoradiography as an analytical procedure was described. Fast radiochemical mrthods for the determination of impurities in aluminium, zirconium and iron have been developed (I’. ALBEKr-France). The scnsi tivity limits were given for the determination of cprtain impurities by means of instrumental activation analysis. and also for methods in\rolving chemical separations after or before neutron irradiation. Niobium and tantalum have been drtrrmined in ores and wastes (C. K. Kn+Republic of Korea) and sodium in solution and in silica-alumina gels
(I’.
Br;ssn%k.~Francc)
.
Various equipment used in an activation analysis programme was described (D. GIBIXXV+LJ.K.). Several applications were discussed in some detail, e.g. determinations of rubidium, calcium, selenium and cobalt, by means of short-lived isotopes. Formulae have been developed for the evaluation of activity data obtained by means of coincidence techniques (M. A. Dx-Netherlands).
C:ICFPOLOTTI-
Italy,. of strontium Apfllicntions in Of the two production iodine- 132 (H. SORANTIN--:\ustria
in rat papers and
M.
in this .\NBAR-
335
Israel). In the latter, a method for the determination of the rate of thyroxine deiodination in humans was also given. An electrochemical technique has been developed to label albumin and other compounds with Br-82 (U. ROSA-Italy). Formulae were given for the intracellular conThese have centration of sodium and potassium. been tested using tracer methods !K. IT.UIAK.~-
Japan).
metabolic technique (R. four freeze-cutting, P-therapy
autoradiography a frozrn was Republic Germany). freeze-drying, freeze-grinding compared. loaded have used PxRQuxN-Franc?). use
,\Nn.4R--Israel). Studies in bone physiology showed that F-follows calcium. As another examplr, fluoroborate ions were found to accumulate in the thyroid gland. The browning of fruits and vegetables had initiated studies of the mechanism of enzymes, with CL-64 as a tracer (J. C. A2~~~~~~,JR.-U.S..k~. It was found that a dissociable bond exists bctwren the enzyme and copper and gives the enzymatic action of copper oxidase. The isotopic exchange of potassium in an illite had been studied in detail (hf. E. SUMMER -Xetherlands.) This included studies of the influence of other ions, among which NH,+ showed a strong blocking of the entry of K-42 into the lattice. This seminar was the first international gathering dealing with the applications of Jhort-liwd radioisotopes. aZs with all international meetings it scrlretl the exchange of information bet\vcen a dual purpose: sophisticatrd isotope users, and the promotion of thra isotopr applications in less developed industries and countries. The immediate benefits of this seminal srem to apply mainly to the former and from this point of view the semmar must be concludrd to have bern well worth-while. However, the versatility of
336
K@Od
sllort-livccl radioisotopes as tracers and as a tool in activation analysis became obvious from the pa*xw I-cad at the suninar, and the prorrcdings of the wminar shoulcl 1~~11)to svrvc also thv latlcr purposes. It seems highly dcsirablr that cormtrivs with small IxxYwCh rc~aCiors ant1 also. br instancr~. heavilx intl~~strinlizcd arcw in tl!c vicinitv of suc11 rcarwrs