Manmade: All commercially used promethium is created in nuclear reactors. Traditional production of promethium-147 is from processing uranium fission products with high-activity and a yield of 2.25%. Although high-levels of radioactive waste are generated during the processing, this process is the primary method of production for commercial quantities. An alternate method of producing promethium-147 uses a High Flux Isotope Reactor (HFIR). In this process, enriched neodymium-146 is irradiated in the HFIR to create neodymium-147 in the peripheral target positions which decay to promethium-147. The yield from the HFIR process is lower than that from uranium fission but will provide promethium-147 in useful quantities of 500 to 1000 curies for research and development (Knapp, Mirzadeh, and Boll, 2007).
1 Extremely small trace amounts of promethium have been identified in the uranium mineral pitchblende.
Beaudry and Bernard J. and Karl A. Gschneidner, Jr., 1978, Preparation and Basic Properties of the Rare Earth Metals: chapter 2 in Handbook of the Physics and Chemistry of Rare Earths-Volume 1:Metals, (Gschneidner, Jr. and Eyring, editors), North-Holland, New York, p. 173-232.
Belli, P., R. Bernabei, F. Cappella, R. Cerulli, C.J. Dai, F.A. Danevich, A. d'Angelo, A. Incicchitti, V.V. Kobychev, S.S. Nagorny, S. Nisi, F. Nozzoli, D. Prosperi, V.I. Tretyak, S.S. Yurchenko , 2007, Search for a decay of natural europium: Nuclear Physics, v. A, no. 789, p. 15-29.
Chikalla, T.D., C E. McNeilly, and E.P. Roberts, 1972, Polymorphic Modifications of Pm2O3: Journal of the American Ceramic Society, v. 55, no. 8, p. 428.
Knapp, F.F. (Russ), Saed Mirzadeh, and Rose Boll, 2007, ORNL Nuclear medicine program develops efficient method for separation of promethium-147 from reactor-produced neodymium-147: Isotope News, U.S. Department of Energy, Spring/Summer 2007, v. 1, issue 1, p. 5-7.
Marinsky, Jacob A., Lawrence E. Glendenin, and Charles D. Coryell, 1947, The chemical identification of radioisotopes of neodymium and element 61: Journal of the American Chemical Society, v. 69, p. 2781-2785.
Weeks, Mary E., and Henry M. Leicester, 1968, Discovery of the Elements (7th ed.): Easton, Pennsylvania, Journal of Chemical Education, 896 p.
Weigel, Fritz., 1963, Darstellung von metallischen promethium: Angewandte Chemie, May 21, v. 75, issue 10, p. 451.
Wheelwright, Earl J., 1969, Preparation of promethium-147 metal and determination of the density and melting points: Journal of Physical Chemistry, September, v. 78, no. 9, p. 2867-2871.