the radiophotoluminescence property of some materials makes it possible to use them for dosimetry purposes. the silver activated metaphoshate glass 1 as an rpl dosimeter when exposed to x. or y radiations , forms fluorescent centers with long lived states ( metastate ). the silver ions (ag+) in unirradiated state produces vacancies when energy is supplied by irradiation the release of electrons...

The flux and the spectrum of reactor antineutrinos depend not only on the current reactor state, which is specified by the power level and the isotope composition of the nuclear fuel used, but also on the preceding evolution of the fuel. The spectrum of antineutrinos produced in the beta decay of fission products and other radioactive nuclei accumulated in the reactor core begin to evolve towar...

So far 22 criticality accidents have been reported (McLaughlin et al., 2000) including JCO accident in Japan. All cases took place with fuel solution or slurry except one case of metal fuel. It was not clear that what was actually happening during those criticality accidents except the JCO accident, for which a fission power profile was reproduced from a gammaray monitoring data (Tonoike et al....

In the normal operation of nuclear reactors, kinetic behavior neutron population in core is driven by so-called delayed neutrons (DN). The DN yield per fission, their average lifetime and groups’ abundances are main physical parameters used to predict reactor its reactivity. overall uncertainty associated reactivity predictions, which linked directly safety margins, thus closely dependent on a ...

Reactor noise, caused both by the probabilistic nature of the fission chains and external reactivity noises, is one of the basic topics in nuclear science and engineering, both in theory and practice. Classical approaches to modeling this noise and neutron count distribution in the detection system rely on the stochastic transport equation for the probability generating function and on transfer...

Small modular reactors (SMRs) are those nuclear fission reactors with electrical output powers of less than 300 MWe. Due to its inherent safety features, the modular high temperature gas-cooled reactor (MHTGR) has been seen as one of the best candidates for building SMR-based nuclear plants with high safety-level and economical competitive power. Power-level control is crucial in providing grid...

Since its discovery 75 years ago fission has been at the forefront of nuclear science and engineering research. Although the fission process is being used worldwide to generate safe reliable power, there are several aspects of the fission process which are still not well known. One such parameter of the fission process is the prompt fission neutron spectrum (PFNS). Although the average number o...

1. Definition of Catalytic Properties 1.1. Conversion 1.2. Selectivity 1.3. Yield 1.4. Catalyst Deactivation and Sustainability 2. Reactor Types 2.1. Batch Reactor 2.2. Perfectly Mixed Flow Reactor 2.3. Plug Flow Reactor 3. Intrinsic Kinetics 3.1. External Mass and Heat Transport Limitations 3.2. Internal Mass and Heat Transport Limitations 3.3. Flow Pattern Ideality 4. Specific Reactor Types 4...

Intrinsic neutron noise experiments offer a non-invasive manner to measure the prompt decay constant or reactivity of fissile systems. Using fluctuations in density fission chains, one can infer kinetics parameters via correlation analysis such as Rossi-alpha method. The models allowing for interpretation these measurements typically rely on assumption system behaving according point kinetics. ...