Nuclides specification

Although following similar nuclear reaction schemes, nuclear analytical methods (NAMs) comprise bulk analysing capability (neutron and photon activation analysis, NAA and PAA, respectively), as well as detection power in near-surface regions of solids (ion-beam analysis, IB A). NAMs aiming at the determination of elements are based on the interaction of nuclear particles with atomic nuclei. They are nuclide specific in most cases. As the electronic shell of the atom does not participate in the principal physical process, the chemical bonding status of the element is of no relevance. The general scheme of a nuclear interaction is ... 

Many countries have more or less elaborate monitoring networks. Long after the Chernobyl accident several countries installed or extended automatic networks, obviously owing to political and public pressures. It is to be hoped that monitoring on a discontinuous and nuclide-specific basis, which is necessary for assessing the contamination of the environment, food, and the public, will not be neglected in favour of costly automatic networks (which in the case of a severe accident may provide a quick warning, but no information on isotopic composition, chemical form, and contamination of the food chain). 

A more detailed investigation of commercially available filter materials on another air-dust sampler which maintains flow rates of more than 850 m /h over the whole sampling period recently revealed nuclide-specific collection efficiencies of more than 95% for one single filter layer (Arnold et al., 1994). 

Monitoring and observation Monitoring of contamination observation of nuclear plant observation of nuclear weapons, military disaster procedures radioactivity in the environment (gamma dose rate, nuclide-specific activity measurement)... 

Gyromagnetic ratio, y. Syn. magne-togyric ratio. A nuclide-specific proportionality constant relating how fast spins will process (in radians. sec ) per unit of applied magnetic field (inT). 

From the average effluents data UNSCEAR determined the collective doses for a model site based on nuclide specific dose-conversion coefficients, which were calculated applying a simple dispersion model, nuclide specific transport parameters, and population density data of 400 km for 1-50 km, 20 km for 50-2,000 km. The normalized collective effective doses... 

In some countries, the radioactivity limits for releasing the stones have become nuclide specific. This will require the use of a multi-channel analyser as well as a system for determining the beta emissions from the stones. 

The nuclide specific clearance levels shown in Table 1 are the lowest values from all the metals studied. Regulatory control can be relinquished if activity concentrations are below these levels, whoi applied as set out below ... 

The nuclide specific clearance levels in Table 1 apply to metal components, equipment or... 

Activity in released nuclide specific analysis, total alpha and total beta On-hne equipment and/or sampling Practice, emergency... 

Aerosol activity in air Filter sampling nuclide specific exposure Practice, emergency. 

Activity in rain chemical form nuclide specific analysis Sampling in rain collector nuclide Practice, emergency... 

Activity in soil planchet sampling and nuclide specific analysis In situ gamma spectrometry field Practice, emergency. 

Activity in foodstuffs Field sampling nuclide specific Practice, emergency. 

Radioactive isotopes of an element have similar environmental and toxicological behavior to the non-radioactive isotopes. If they are introduced into the body by inhalation ingestion, the chemical properties of the element will determine its ultimate destination in the body. For example, it is well known that strontium and radium are chemically similar to Ca and tend to deposit on bone surfaces and bone marrow with that element tritium ( H) becomes incorporated into water molecules and is distributed throughout the body. The main difference between radioactive and nonradioactive isotopes is that the radionuclides emit one or more types of radiation as they decay to more stable forms. The type and energy level of the emitted radiation is nuclide-specific. 

---