31 Key - 99Mo / 213Bi
Molybdenum - 99
Bismuth - 213
99Mo is currently used in NMR as the detection drug.  Currently only 1 reactor in Canada produces the whole North American supply of 99Mo.  This reactor is currently scheduled to close in 2015.  A standard Molten salt Reactor can be built with the option of producing 99Tc the precursor for 99Mo.
225Ac (10 Day Half-Life) / 213Bi (45 Min Half-Life)
Used in Dispersed Cancer Treatments (Leukemia, Pancreatic Cancers and Stomach Carcinoma)
Sequential Cytarabine and α-Particle Immunotherapy with Bismuth-213–Lintuzumab (HuM195) for Acute Myeloid Leukemia 
One decay away from stable isotope
Alpha Emitter + Antibody = Effective Cancer Fighting Agent
AC / Bi Generator - ITG 225Ac/213Bi Alpha Generator
“225Ac and 213Bi are currently derived from purified Th-229 extracted from 233U at ORNL. The only practical way at present is to derive these isotopes from the natural decay of 229Th. 229Th is produced by the natural decay of 233U. 225Ac is the product being shipped to medical facilities. 213Bi is separated from the 225Ac at the hospital and combined with the targeting agent.
“213Bi appears to be very potent, so only a very minute quantity may be needed to treat a patient…on the order of a billionth of a gram.”