MEASUREMENT OF N16 ACTIVITY AT NUCLEAR POWER PLANTS
The aim of the N16 activity measurement at nuclear power plant is the monitoring of potential steam generator leakage. The measurement is based on the determination of the activity concentration of radionuclide N16 (nitrogen 16) in a hot steam in the steam pipe.
Radionuclide N16 is the result of neutrons and protons reaction occurring on oxygen atoms (in water molecules) in the reactor core. As the number of oxygen atoms in the core is constant and the neutron flux is directly proportional to reactor power, the calculation of N16 activity concentration in the primary
coolant at the reactor core outlet is possible.
Since the radionuclide N16 has short half-life (7,13 sec.), it is necessary to perform corrections on its activity decrease along the transport from the reactor core to the point of steam generator leakage, via steam generator secondary side and steam pipe up to the point of measurement. Necessary technological data (main circulation pump operation, steam generator power etc.) are entered in the computation program due to this correction.
|
