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  Thermal hydraulics modelling of low-pressure, light water-cooled Small Modular Reactors

   Department of Mechanical, Aerospace and Civil Engineering

   Applications accepted all year round  Competition Funded PhD Project (Students Worldwide)

About the Project

The Low-Pressure Water Reactor (LPWR) is a 300MW(e) pool-type water-cooled Small Modular Reactor (SMR) design in which the nuclear core is located at the bottom of a deep underground shaft instead of inside a pressure vessel. The operating pressure of the LPWR is close to atmospheric in contrast to the pressures 70 atmospheres or above that apply to current water-cooled power reactor designs. Pool reactors have been used in the past for research or for radioisotope production purposes but have not previously been proposed for electrical power generation. The LPWR design is unique in being a pool reactor whose only purpose is commercial electrical power generation.

The main advantage of the LPWR over current high-pressure water reactor designs is that no circumstances exist in which there could be a rapid loss of coolant from the reactor shaft and therefore the nuclear fuel cannot overheat or melt even in the most extreme fault conditions. Much of the high capital and construction costs of current water-cooled reactor types are due to need for complex safety features and equipment to prevent core overheating in hypothetical accidents such as pressure circuit failure. In the LPWR the probability of the core overheating in such accidents is negligibly small, offering the possibility of simplified construction, reduced construction and maintenance costs and easier public and regulatory acceptance.

In this project you will develop a numerical simulation framework to model the thermal-hydraulics behaviour of the LPWR at system level. The LPWR core operates in two-phase flow conditions with vapour generation and buoyancy effects, which may cause flow instabilities to occur. There is a requirement to predict and understand such flow behaviour in order to develop a design assessment of the LPWR, which is a real challenge in that flow instabilities are notoriously difficult to model at system level. It is therefore vital to devise and validate a robust simulation methodology capable of addressing the instabilities of the LPWR and apply it to find strategies for achieving a stable core flow in normal operation. Via pioneering predictive methods for LPWR thermal hydraulics, this project will potentially enable significant advancements in civil nuclear power generation: it also envisages close collaboration with industry partners and the possibility to seek additional funding from industry for knowledge transfer and further collaboration.


Applicants should have, or expect to achieve, at least a 2.1 honours degree or a master’s in a relevant science or engineering related discipline.

Before you apply

We strongly recommend that you contact the supervisor for this project before you apply.

How to apply

To be considered for this project you’ll need to complete a formal application through our online application portal.

When applying, you’ll need to specify the full name of this project, the name of your supervisor, how you’re planning on funding your research, details of your previous study, and names and contact details of two referees.

Your application will not be processed without all of the required documents submitted at the time of application, and we cannot accept responsibility for late or missed deadlines. Incomplete applications will not be considered.

If you have any questions about making an application, please contact our admissions team by emailing .

Equality, diversity and inclusion is fundamental to the success of The University of Manchester, and is at the heart of all of our activities. We know that diversity strengthens our research community, leading to enhanced research creativity, productivity and quality, and societal and economic impact.

We actively encourage applicants from diverse career paths and backgrounds and from all sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation and transgender status.

We also support applications from those returning from a career break or other roles. We consider offering flexible study arrangements (including part-time: 50%, 60% or 80%, depending on the project/funder).


At Manchester we offer a range of scholarships, studentships and awards at university, faculty and department level, to support both UK and overseas postgraduate researchers.

For more information, visit our funding page or search our funding database for specific scholarships, studentships and awards you may be eligible for.

This project is also eligible for the Osborne Reynolds top-up Scholarship which provides an additional £1500 per year top-up to other funding sources for outstanding candidates. Successful applicants will be automatically considered for this top-up.

Please note that we are now accepting nominations for the Dean's Doctoral Scholarship for September 2024.

Computer Science (8) Engineering (12) Mathematics (25) Physics (29)

Funding Notes

At Manchester we offer a range of scholarships, studentships and awards at university, faculty and department level, to support both UK and overseas postgraduate researchers. Please see the project description for more details.

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