Bernstein says he and his colleagues are testing alternative detectors made of water or solid plastic. The mineral oil–based detector is relatively difficult to deploy, he says, and might pose a safety risk to IAEA inspectors from the 1,2,4-trimethylbenzene, which is toxic and flammable [see note below].
Another challenge might be the need to place the detector underground, which not all nuclear facilities may have space for, says Juan Collar, a physicist the University of Chicago who works on neutrino detection. Monteith notes that Brazil plans to test aboveground detectors.
And other, more experimental detectors might be easier to place in a reactor. Collar and Bernstein are both part of teams attempting to observe a different type of interaction between protons and antineutrinos that would require more sensitive detectors but would occur 100 to 1,000 times more frequently than in existing technologies, Collar says, allowing for smaller devices.
Correction (5/9/08): The original article implied that 1,2,4-trimethylbenzene would be in close proximity to the reactor core, which is not the case.