(NEWSER) - Trouble at nuclear reactors that produce two-thirds of the world’s medical isotopes have created massive testing delays in the US, the Philadelphia Inquirer reports. The isotopes, created in Canada and the Netherlands, are used for presurgery stress tests and to locate some cancers; doctors are limping along with older, less effective ones. The Canadian reactor is offline indefinitely because of a leak, and the iffy Dutch one is scheduled for 6 months of maintenance next year. More»