The development of accelerator driven sub-critical systems (ADSS) require significant amount of new nuclear data in extended energy regions as well as for a variety of new materials. This paper reviews these perspectives in the Indian context.

Nuclear data requirements for accelerator driven sub-critical systems — A roadmap in the Indian context

The nuclear data of the major actinide fuel materials

AbstractThe probability table method, developed for Monte Carlo calculations in the region of unresolved neutron resonances, is demonstrated to be of general use in neutron transport studies since the Boltzmann equation involved can be derived and solved by analogy to multigroup methods. Since the resulting equations can be cast into a form identical to that of the multigroup equations, they can be solved by existing multigroup transport codes. From a set of probability tables and spatially independent, unshielded, neutron cross sections, the method yields correct selfshielding effects, such as equivalent, spatially dependent, multigroup cross sections. Extension of the method and the use of probability tables outside the unresolved region are discussed.

Application of the probability table method to multigroup calculations.

Verification of the accuracy of Doppler broadened, self-shielded multigroup cross sections for fast power reactor applications

Using two different approaches, the self shielding factors were generated for 239Pu, 235Pu, Fe and Na and compared with available experimental values. The first method uses J⋆ formalism of Hwang which employs ψ and χ approximations and additional approximations in the formulation and numerical evaluation of the J⋆ integrals. The other method which uses Cullen’s codes avoids these approximations. The present comparison studies support the recent investigations performed at Kalpakkam towards the objective of evolving a correct method of calculation of self shielding factors in the resonance region. The results show that at lower background dilutions there is a wide dispersion among the values of self shielding factors calculated by two different methods and those obtained experimentally. At higher dilutions the values of self shielding factors calculated by both the methods converge towards experimental values satisfactorily.

Comparisons of calculated self shielding factors with measured values.

On the need for changing the ENDF/B convention for the representation of cross-sections in the unresolved resonance region of fertile and fissile nuclei

S. Ganesan

Papers

On the need for changing the ENDF/B convention for the representation of cross-sections in the unresolved resonance region of fertile and fissile nuclei