Submitted by delores on Fri, 07/10/2009 - 10:00.
Author and researcher Anna Tilman shares this understanding of the medical isotope crisis due to the failure of the reactor at Chalk River
Much ado is being made out about the shortage of medical isotopes as a result of the shutdown of Atomic Energy of Canada Limited (AECL)’s Chalk River’s 52-year old National Research Universal (NRU) reactor due to “leaks” of radioactive tritium-laced heavy water. This is the second shutdown in just 6 months at this facility which is on the shores of the Ottawa River about 185 kilometres from Ottawa.
At the time of the second reported leakage in May 2009, expectations were that the reactor would get back on track within a few months. It is now apparent that the reactor will not be functional for at least a year, and even so, if at all.
While there are many isotopes used in nuclear medicine, the critical isotope in question is technetium - 99m (Tc-99m), a short-lived decay product of Molybdenum-99 (Mo-99), and the current workhorse of radioisotopes in nuclear medicine used internally for imaging soft tissues. The short half-lives of these radioisotopes make timing a critical issue. While M0-99 has a half-life of 66 hours, the half-life of Tc-99m is only 6 hours. In just 24 hours, only about 6% of the initial amount of Tc-99m remains, the rest having decayed to other elements.