# Thermal Hydraulics: Solving a PWR Problem

• soha
In summary, the conversation discusses a problem in a Nuclear thermal hydraulics course involving a PWR operating at 1893MW and 193 fuel assemblies with 204 UO2 fuel rods each. The equation provided has 200MeV and 180MeV as deposited and recoverable energies per fission, and extrapolated values for radius and height. The question asks for the location of the rod with maximum heat generation and the maximum heat generation rate per unit volume in that rod. The conversation also discusses the need for an equation and assumptions for axial and radial power shapes, and the occurrence of maximum values at r and z = 0. The center of the core is identified as the location of maximum heat generation and the use of
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 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??

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

This is the given eqn

#### Attachments

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

when r and z = 0

soha said:
when r and z = 0
Which is where in the core?

Astronuc said:
Which is where in the core?
The center of the core

soha said:
The center of the core
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.

## 1. What is thermal hydraulics?

Thermal hydraulics is a branch of science that deals with the study of the behavior of fluids (liquids and gases) in relation to heat transfer. It involves understanding the movement of fluids, the transfer of heat between fluids and surrounding surfaces, and the effects of this heat transfer on the fluid's temperature and flow.

## 2. What is a PWR?

A PWR (Pressurized Water Reactor) is a type of nuclear reactor that uses water as both a coolant and a moderator. The water is heated by nuclear reactions and then pumped through the reactor core to remove heat and generate steam, which is then used to power turbines and produce electricity.

## 3. What is a PWR problem?

A PWR problem refers to any issue or malfunction that affects the operation of a PWR nuclear reactor. This could include problems with the reactor's cooling system, control rods, or other components that could lead to a decrease in efficiency or potential safety hazards.

## 4. How are PWR problems solved using thermal hydraulics?

Thermal hydraulics plays a crucial role in addressing PWR problems by helping to understand and analyze the behavior of the reactor's cooling system and other fluids. Through computer modeling and simulations, thermal hydraulics can predict how the reactor will respond to different scenarios and help engineers develop solutions to address any potential issues.

## 5. What are some common PWR problems that thermal hydraulics can help solve?

Some common PWR problems that thermal hydraulics can help solve include design and operational issues, such as optimizing the cooling system to improve efficiency, identifying and addressing potential safety hazards, and predicting and preventing equipment failures. Thermal hydraulics can also aid in the design of new PWR systems and the development of advanced reactor technologies.

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