Nuclear fuel fabrication facilities often require quick characterization of plutonium bearing samples which may contain high concentrations of plutonium. Plutonium bearing samples generate alpha tracks on SSNTDs having very high density due to the high specific activity of plutonium often resulting in crowded tracks. Assessment of nuclear track density of SSNTDs with crowded tracks is very challenging and difficulty level increases with increase in plutonium concentration in the sample. A novel method to estimate densities of crowded alpha tracks and also computing the alpha fluence values for samples having very high plutonium concentration was developed using UV–Vis spectral features of the irradiated polymer. Structural modifications of the polymer were also investigated for samples with low, high and very high concentrations of plutonium.