A Year of Radioisotopes O n t h e a n n i v e r s a r y o f t h e first s a l e o f r a d i o i s o t o p e s t h e A t o m i c Energy C o m m i s s i o n reviews t h e work t h a t has been accomp l i s h e d >vith t h e s e t o o l s a n d o u t l i n e s t h e s h a p e o f t h i n g s t o c o m e
J\. TOTAL of 1,092 shipments of more t h a n 100 différent radioisotopes have traveled a distance of 1,£80,000 miles since the first sale of carbon 14 was made j u s t a year a g o . On the occasion of this first anniversary, falling on Aug. 2, the Atomic Energ3 r Commission, has summarized the activities of the Clinton Laboratory in the field of radioisotopes produced from the chain reacting pile. A t the same time, it has issued its semiannual report to t h e Congress. Highlights of interest to the chemical industry follow: Production Largest single activity is the production of fissionable materials—U 2 3 5 a t Oak Ridge and plutonium at t h e Hanford Engineering Works. Carbide and Carbon Chemicals Corp. has operated the gaseous diffusion p l a n t since its erection and on M a y 5 took over operation of the electromagnetic separation plant from TennesseeE a s t m a n Corp., effecting a considerable reduction in overhead expense. General Electric continues as the contractor a t Hanford. A n expansion program is in progress to construct additional chemical processing plants. Work on isotopes has been under the over-all direction of Charles A. Thomas of Monsanto Chemical Corp. Actual production for sale and distribution is the job of L. B. Emlet, 1. B. Whitney, and H. E. Bedcil. F r o m 60 elements some 100 varieties of radioisotopes have been made. T h e y are produced in several ways, i.e., inserting small amounts of elements into t h e chain-reacting pile, or by " t r a n s mutation." This -latter is effected b y t h e emission of a proton by the nucleus after t h e capture of a neutron. Carbon 14 is produced in this way b \ r the bomb a r d m e n t in t h e pile of the nitrogen atoms in calcium nitrate. Individual projects are broken down a s follows: Weldon Brown, formerly of t h e University of Chicago, directs production of organic chemical compounds containing radioactive carbon. Methanol containing the C 14 atom, will soon become available for research. Waldo E . Cohn, formerly of H a r v a r d Medical School, is in charge of P 3 2 , i m p o r t a n t in medical a n d biological research. L. D. Norris is working to establish the r a t e of atomic disintegration of isotopes. R. T . Overman and W. C . Peacock are establishing decay schemes which indicate the manner in which t h e substances disintegrate. Separation of 2202
isotopes from parent target materials is u n d e r A. F . R u p p . W. A. Rodger supervises development of phosphorus a n d carbon radioisotopes from laboratory scale to production scale. For example, cost of carbon 14 is now S50 a millicurie. T h e same q u a n t i t y of cyclotron-produced C 1 4 would have cost SI million. Shipment
of
Radioisotopes
A radioisotope is shipped to a purchaser in a wooden box inside which is a lead shield up to 0.5 inch thick. Inside t h e shield is a stainless steel cylinder containing a glass bottle which bears the isotope. Packages are checked to determine t h e a m o u n t of radiation a t the surface a n d m u s t be repacked with a thicker shield if t h e radiation is above tolerance Largest shipment was that of 23 g r a m s of C o 6 0 to the National Bureau of S t a n d ards. T h e weight of the cobalt was e q u a l to t h a t of a 50-cent piece. T h e package t h e bureau received weighed 1,600 lb. Expediting shipment is vital since halflives m a y be as short as 2.7 days for radiogold or 12.4 hours for radioactive potassium. Such elements are shipped b\ r air on lines t h a t are willing to accept such cargo. Purchasers receive film badges similar to those worn by workers a t t h e Clinton Laboratories so they can check on t h e amount of radiation exposure. Answering objections of airline c o m panies which fear the radioactive cargoes will affect instruments, the laboratories h a v e established t h a t a package normally e m i t s the same amount of radiation as t h e dial of a luminescent watch. Industrial
Uses for
Isotopes
A t t h e Massachusetts I n s t i t u t e of Technology, which has received a g r e a t e r v a r i e t y of isotopes t h a n other i n s t i t u tional customers, John T. Burwell, J r . is working with steel made radioactive in t h e Clinton pile to learn what h a p p e n s t o m e t a l during friction and wear. The m e t h o d enables detection of as little a s one hundred-billionth of an ounce of m e t a l transferred from surface to surface b y friction. T h e petroleum industry has a l r e a d y developed to a high degree methods using radioisotopes in oil well logging. M e t a l lurgists a r e studying aging of ferrous materials, thermionic activity of filaments, a n d absorption of gases in metals with isotopes. T h e steel industry is using t h e m in developing a controlled m e t h o d for removing sulfur from iron when t h e iron is separated from the slag. C H E M I C A L
Reaction efficiencies in the petroleum cracking process can be studied when longchain hydrocarbons are tagged and can be traced through all reactions and side reactions. New types of studies of catalytic action were made possible. Biological researchers have found t h a t radiosulfur can be incorporated into crystalline penicillin when it is grown on media containing the sulfur. Application of radioisotopes in fundamental research is their most important use. Studies of the thin layers of molecules and ions which attach themselves to glass or metal surfaces m a y yield information of use in t h e fields of catalytic action, electroplating, mirror formation, and detergent action. Radioactive chlorine, bromine, and iodine a r e being used to study exchange reactions of these elements with molecules containing t h e same elements. J o h n E- Willard of the D e p a r t m e n t of Chemistry a t the University of Wisconsin where these latter investigations are under way, has received the greatest variety of isotopes shipped to any individual. Radioactive potassium, rubidium, and calcium are being used in studies of the chemistry of soil a n d the storage of potash in the soil. Training
Programs
T h e Commission, through assignment of space a n d technical services a t Oak Ridge, is continuing to assist the training of special groups of Service personnel in nuclear physics. I t is assisting studies of the possibility of applying nuclear energy to propulsion of aircraft, a combination project of the Army Air Forces a n d the Fairchild Engine and Airplane Corp. It is giving help to the N a v y in connection with exploration of application of nuclear energy to propulsion of ships. Dissemination
of
Information
D u r i n g the past y e a r approximately 1,200 scientific papers were declassified by the Commission. In its report t o the Congress the A E C points out t h e necessity for a balance between control a n d dissemination of information, a s well a s the importance of n o t going to extremes for t h e sake^ of security. I n the words of the report, it m u s t "strive t o inspire talented men to enter t h e new field a n d give them t h e information they need in order to proceed." Budget
and
Personnel
T o t a l allocations of §644,916,353 were m a d e to t h e Commission since N o v . 13, 1946 from M a n h a t t a n Project funds. Out of these allocations $40 million have been restored to t h e surplus of the treasury. T h e Commission's payroll numbers 4,133, with half this personnel a t Oak Ridge, less t h a n 200 in Washington. T o t a l employment, including employees of contractors, was 41,513 o n May 3 1 . AND
ENGINEERING
NEWS
