# Thermal hydraulics

1. May 31, 2015

### soha

Hi guys,

I'm a starter in Nuclear thermal hydraulics course, and I'm having a hard time in solving this problem:

1. Consider a PWR operating at the thermal power of 1893MW. It contains 193 fuel assemblies, each consisting of 204 UO2 fuel rods 1cm in diameter. Using the equation

http://file:///C:\Users\Koki\AppData\Local\Temp\msohtmlclip1\01\clip_image002.png [Broken]

With 200MeV and 180MeV deposited and recoverable energies per fission respectively, and extrapolated radius of 170.2cm and extrapolated height of 365.76cm. Determine the location of the rod with maximum heat generation then calculate the maximum heat generation rate per unit volume in that rod.

can anyone help??

Last edited by a moderator: May 7, 2017
2. May 31, 2015

### Astronuc

Staff Emeritus
One needs to provide an equation. What axial and radial power shapes does one assume for the core?

3. May 31, 2015

### soha

This is the given eqn

#### Attached Files:

• ###### eqn.jpg
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4. May 31, 2015

### Astronuc

Staff Emeritus
OK, so where do the maximum values occur for a cosine ( cos (x) ) and Jo ( Jo(r/R) ) Bessel's function?

5. May 31, 2015

### soha

when r and z = 0

6. May 31, 2015

### Astronuc

Staff Emeritus
Which is where in the core?

7. May 31, 2015

### soha

The center of the core

8. May 31, 2015

### Astronuc

Staff Emeritus
Correct, or half-way up from the bottom of the core along the central axis.

One should able to apply the equation with z and r = 0 to find the local power.

What is the lattice for an assembly with 204 fuel rods? How many guide/thimble tubes? Assume one central tube for instrumentation.