A 2D DNA lattice as an ultrasensitive detector for beta radiations.

There is growing demand for the development of efficient ultrasensitive radiation detectors to monitor the doses administered to individuals during therapeutic nuclear medicine which is often based on radiopharmaceuticals, especially those involving beta emitters. Recently biological materials are used in sensors in the nanobio disciplines due to their abilities to detect specific target materials or sites. Artificially designed two-dimensional (2D) DNA lattices grown on a substrate were analyzed after exposure to pure beta emitters, (90)Sr-(90)Y.

Development of optical monitor of alpha radiations based on CR-39.

Fukushima accident has highlighted the need to intensify efforts to develop sensitive detectors to monitor the release of alpha emitting radionuclides in the environment caused by the meltdown of the discharged spent fuel. Conventionally, proportional counting, scintillation counting and alpha spectrometry are employed to assay the alpha emitting radionuclides but these techniques are difficult to be configured for online operations. Solid State Nuclear Track Detectors (SSNTDs) offer an alternative off line sensitive technique to measure alpha emitters as well as fissile radionuclides at ultra-trace level in the environment.

A novel nanometric DNA thin film as a sensor for alpha radiation.

The unexpected nuclear accidents have provided a challenge for scientists and engineers to develop sensitive detectors, especially for alpha radiation. Due to the high linear energy transfer value, sensors designed to detect such radiation require placement in close proximity to the radiation source. Here we report the morphological changes and optical responses of artificially designed DNA thin films in response to exposure to alpha radiation as observed by an atomic force microscope, a Raman and a reflectance spectroscopes.

Determination of alpha activity in organic solvents using CR-39.

Solid State Nuclear Track Detector (SSNTD) like CR-39 offers a unique opportunity to measure alpha radiations in a complex matrix like high level nuclear waste due to its sensitivity to only alpha radiations in the presence of intense beta-gamma radiation field. There is however a concern about the lower sensitivity of SSNTD when the radiation source is present in solution vis-à-vis solid medium. The sensitivity of CR-39 toward detection of alpha particles homogenously distributed in n-hexane, n-dodecane and n-octanol has been investigated and was found to be better than that obtained in 3 M HNO3.

A novel approach for preferential recovery of Sr from (Sr, Th)O2.

Quantitative leaching of Sr from homogeneous and calcined (Th,Sr) O(2) in dilute perchloric acid medium suggests the possibility of reducing the hazardousness of discharged nuclear fuel by separation of (90)Sr, a prominent fission product at dissolution stage itself rather than the conventional approach of its recovery from high level nuclear waste. Apart from mitigating the radiotoxicity of the nuclear waste, recovered (90)Sr can be employed as a compact heat source and as parent radionuclide for (90)Y (used in therapy radiopharmaceuticals), provided it can be made available at desired high purity. Leaching behavior of few other fission products was also investigated to quantify their contamination in leached Sr.