Question

Homework-9

Due:

Q) A fuel plate is fabricated from 0.3 cm thick 1.5% enriched uranium. The cladding is 0.25 mm 304 stainless steel. The coolant saturation temperature is 260 ^oC. The average thermal neutron flux is 2.5 X 10¹⁴ neutrons/cm² /s. The surface temperature of the clad is 350 ^oC.

Assume any missing data to answer the following questions:.

1) Write an expression of the heat generated per unit volume

2 What is the heat flux at the surface of the fuel?   

3) What is the temperature at the fuel-clad interface?

4) What is the maximum fuel temperature, and where?

5) What is the minimum fuel temperature, and where?

6) How much heat (in joules) is transported to the coolant in one second and one hour?

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Homework- 10

Q1) A spherical metal ball of radius r₀  is heated in an oven to a temperature of 600 ⁰F throughout and is then taken out of the oven and allowed to cool in ambient air at T_∞ = 78 ^oF. The thermal conductivity of the ball material is K = 8.3 Btu/h.ft.R, and the average convection heat transfer coefficient on the outer surface of the ball   is h= 4.5 Btu/h.ft².R. The emissivity of the outer surface of the ball is   ε = 0.6, and the average temperature of the surrounding surfaces is T_surr = 525 R. Assume the ball is cooled uniformly from the entire outer surface, answer the following questions:

a. write the heat conduction differential equation of the problem,

b. write the initial condition of the problem

c, write the boundary conditions for the cooling process of the ball.

Q2) Heat is generated in a spherical radioactive material, with constant thermal conductivity k = 25 W/m K, at a non-constant rate of  qʹʺ = 45 /( πr/R_o ) W/cm³ . The radius of the sphere is R_o = 1.5 cm. Heat is dissipated to the surrounding medium at 25 ^oC with a heat transfer coefficient of 120 W/m² K. Calculate the surface temperature of the material and the total rate of heat dissipated to the surrounding. Assume 1D steady state operation.

[Please submit the answer using text so I can just copy and paste it, thank you]

Answer 1