Evaluation of some research reactor parameters in Modified Irradiation Site of NIRR-1.

Abstract

The evaluation of I0 ( ) and Q0 ( ) for Gold, Cupper, Thorium, Uranium and Potassium in Modified Irradiation Site of Nigeria Nuclear Reactor-1 (NIRR-1) was done using Instrumental Neutron Activation Analysis (INAA) and off-line gamma ray spectrometric technique. It was found that before the Cd-lined installation i.e. modification of the large irradiation site (A-3) of NIRR-1, the deviation parameter ( ) was positive with a value of 0.024±0.002 indicating high neutron thermalization. However, after the Cd-line installation, the -parameter was found to be negative with a value of -0.9274 ± 0.016 indicating poor thermalization and as a consequence achieved the purposed of the modification. Further correction for Q0 to Q0 ( ) and I0 to I0 ( ) for the nuclides; Au, Cu, Th, U, and K in the modified large outer irradiation channel A-3 were done. Before Cdlined installation the Q0 ( ) values for Au was 15.05, for Cu was 0.88, for Th was 10.05, for U was 0.86 and for K was 90.37. However, after the Cd installation the Q0 ( ) values for Au increased to 139.64, for Cu increased to 4681.32, for Th increased to16661.89, for U increased to 6141.55 and for K it increased to 133177.92. Also, before Cd-lined installation (BF), I0 ( ) values for Au and Cu were 1485.410, 3.870 and after Cd-lined installation they increased to 13782.47 and 18631.64 respectively.