In a nuclear reactor fuel assembly with triangular lattice, water flows upward at pressure

of $77$ bar with inlet subcooling of $12C.$ The fuel assembly has height of $3\mathrm{.}55m,$ fuel rod

diameter of $9\mathrm{.}6mm,$ and fuel lattice pitch of $12\mathrm{.}3mm.$ The fuel assembly has uniform

heat flux of $0\mathrm{.}28M\frac{W}{m^{{?}^{{?}^{?}}}}2,$ and the water flow mass flux is $1,800k\frac{g}{m^{{?}^{{?}^{?}}}}2.s.$

Determine the major locations $($Onset of nucleate boiling, Onset of significant void, and

bulk saturation point$).$

Calculate the axial void fraction distribution $($Plot the distribution using numerical tools,

or manually by selecting typical locations to give void fraction values$).$

Justify the methods and models you used in each step.