Fig. 1. Schematics of R/B and λ of fission products in the primary loops

Fig. 2. Relation between A(¹³⁴Cs)/A(¹³⁷Cs) and fuel burnup

Fig. 3. Trend of measured fission product in the primary loops in PWR

Fig. 4. Relation of R/B and λ for iodine at the 14^th day of operation

Fig. 5. Relation of R/B and λ for iodine and noble gas at the 30^th day of operation

Fig. 6. Relation of R/B and λ for iodine and noble gas at the 308^th day of operation

Fig. 7. Distribution of burnup of fuel assemblies with different batches