NEUTRONIC MODELLING OF THE FFTF CONTROL ROD WORTH MEASUREMENTS WITH DIFFUSION CODES E. Nikitin, E. Fridman, K. Mikityuk, S. Radman and C. Fiorina EPJ Web Conf., 247 (2021) 10017 Published online: 22 February 2021 DOI: 10.1051/epjconf/202124710017