PURPOSE
Determination of the amount of fissile materials (uranium and plutonium isotopes) in various samples and products
using nondestructive analysis (without opening the casing or packing).
APPLICATION
Measurement of the concentration of nuclear materials in products and waste; inventory use at facilities where nuclear materials
are produced, used, or stored.
OPERATION
The counter operation is based on measurement of the intensity and analysis of time correlations of the neutron radiation from
samples placed in the measuring chamber surrounded with highly efficient proportional neutron counters.
Counter control, data acquisition, and processing of results are carried out remotely with the computer connected to the counter
through an electronic module.
There are four operation modes:
- Passive mode of counting the total number of neutrons emitted by the sample,
which provides the highest sensitivity in measurement of spontaneously fissioning
isotopes.
- Passive mode of counting coincidence multiplicity in a given time window,
which allows discrimination between neutrons from spontaneous fission and
neutron from the (α,η) reaction.
- Active mode of counting multiplicity of spontaneous fission neutron coincidences
in bombardment of samples with thermal neutrons from an external neutron source,
which is used to determine the U -235 content of low-enriched uranium.
- Active mode of counting coincidence multiplicity in bombardment of samples
with fast neutrons from an external neutron source, which is used to determine
the U -235 content of highly enriched uranium.
TECHNICAL DATA
| Measuring chamber dimensions, mm |
diameter |
200 |
height |
200 |
| Fission neutron detection efficiency, % |
25 |
| Maximum detectable coincidence multiplicity |
16 |
| Sensitivity to Pu -240 in passive mode of total counting,
mg |
1 |
| Sensitivity to U -235 in active mode with thermal neutrons,
g |
1 |
| Power supply, V |
220 |
| Overall dimensions, mm |
1000 x 700 x 700 |
| Weight, kg |
150 |
|
