Optimized calculation model of ¹⁶N radiation sources in primary coolant of PWR

As the coolant is the main activated product passing through each activation region in the reactor vessel, the neutron in the region will activate the oxygen in water into activated product, such as ¹⁶ N. ¹⁶N is the main product, and it is the most important radiation sources in the primary side. A ¹⁶N radiation sources model is established based on conventional method and primary coolant flow direction, dividing the core area into activation regions and reflection regions. To prove the validity of the calculation model, the integrative calculation of ^l6N radiation sources in the primary coolant was completed. The coolant typical ¹⁶N model equilibrium radiation sources were analyzed. It finds out that the radiation sources are maximum at the core outlet, and are reduced along with the coolant. The study result shows that the optimized calculation model gives more accurate calculation for the ¹⁶N sources. (authors)