|
|
| |
|
| |
|
Development and Application Technology on NAA
|
| |
Reactor Neutron Activation
Analysis |
| |
 |
|
|
Principle |
| |
|
|
Neutron Activation Analysis is a
representative and the most sensitive method of nuclear analytical
techniques used for qualitative and quantitative analysis. Like the
above described figure, while unknown sample is irradiated by neutrons
in nuclear reactor, the target nuclides(stable nuclides) in sample
undergo neutron capture reactions and are converted to radioactive
nuclides(unstable nuclides) emitting beta particles and gamma-rays.
Elemental content in sample can be determined by the measurement of
prompt gamma-rays emitted from the exited compound nucleus during
neutron irradiation or of delayed gamma-rays from the radioactive
nuclides created after irradiation. The former is called PGAA, the
latter is INAA. Since the number of characteristic gamma-ray emitted
per unit time from the interesting nuclides created by nuclear
reaction is proportional to neutron flux and the amount of stable
isotope, elemental content in the sample can be obtained if the
neutron flux of irradiation hole and the nuclear characteristics of
interesting nuclides are estimated.
|
|
|
Characteristics and
Advantages of NAA/PGAA |
| |
|
|
High Sensitivity : the level of 10-7μg(refer to sensitivity chart)
|
| |
Non-destructive analysis : additional contamination can be
avoided and minimized by no
chemical pre-treatment.
|
| |
Simultaneous multi-elemental analysis : 30 ~ 40 elements by single
measurement
(Na ~ U)
|
| |
Absolute method : physical parameters for quantification are
well defined and can be
easily obtained by literature and experiment
|
| |
Free of analytical blank. Linearity in the range of whole
concentration
|
| |
Little matrix interference. In the non-ideal case, correction is
possible
|
| |
While the chemical analysis are based on electromagnetic
characteristics, NAA is, in
principle, independent analytical method which relies on
nuclear properties
|
| |
Estimation and formulation of measurement uncertainty sources
are clear
|
| |
In PGAA, the same samples are reusable for NAA, because the
radioactivity in the
samples after measurement is negligible
|
| |
In PGAA, prompt analysis, especially for light elements, is
possible
|
| |
In PGAA, when the gamma-rays are measured, the statistical
uncertainty due to the
variation of decay of nuclides and dead time is negligible during
measurement
|
|
|
|
| |
|
Sensitivities of INAA/PGAA |
 |
 |
| |
| The Status of Utlization
and Analytical Service of NAA in HANARO |
|
|
|
| |
|
Implementation of
International Cooperative Projects |
| |
UNDP/RCA/IAEA Project |
|
|
- Air Pollution and Its Trends (RAS/97/030/A/01/18) |
|
|
- Quality Assurance and Quality Control of Nuclear Analytical
Techniques
(RAS/97/030;RAS/8082;RAS/0713) |
|
MEXT/JAERI Project : Forum for Nuclear Cooperation in Asia (FNCA) |
|
|
- Utilization of Research Reactor |
|
Korea-Japan Cooperation Project |
|
|
- Development of Neutron Activation Analysis Supporting System |
|
Korea-Chile Technical Cooperation |
| |
|
|
| |
|
|
)
)
