Reduced moderation water reactor

Reduced Moderation Water Reactor (RMWR) is a type of nuclear reactor that is designed to operate with a lower degree of neutron moderation than conventional water reactors. This design feature allows the RMWR to achieve a higher conversion ratio and potentially extend the nuclear fuel cycle.

Design and Operation

The Reduced Moderation Water Reactor operates on the principle of reduced neutron moderation. In a conventional water reactor, water serves as both the coolant and the neutron moderator. The moderation of neutrons is a process that slows down the high-energy neutrons produced in nuclear fission, increasing the likelihood of further fission events and sustaining the nuclear chain reaction.

In an RMWR, the moderation of neutrons is intentionally reduced. This is achieved by designing the reactor core in such a way that the ratio of water to fuel is lower than in conventional water reactors. The reduced moderation increases the average energy of the neutrons in the reactor, which in turn increases the conversion ratio of the reactor.

The conversion ratio is a measure of the number of new fissile atoms produced for each fissile atom consumed in the reactor. A higher conversion ratio means that the reactor produces more new fuel than it consumes, potentially extending the nuclear fuel cycle and reducing the amount of nuclear waste produced.

Advantages and Challenges

The main advantage of the RMWR design is its potential for a more efficient use of nuclear fuel. By achieving a higher conversion ratio, the RMWR could extend the nuclear fuel cycle and reduce the amount of nuclear waste produced. This could have significant economic and environmental benefits.

However, the RMWR design also presents several challenges. The higher average neutron energy in the reactor could increase the risk of radiation damage to the reactor materials. In addition, the reduced moderation could make the reactor more sensitive to changes in the physics of the reactor core, potentially making the reactor more difficult to control.

Development and Future Prospects

The concept of the Reduced Moderation Water Reactor was first proposed in the late 20th century as a potential way to improve the efficiency of the nuclear fuel cycle. Since then, several research and development projects have been undertaken to explore the feasibility of the RMWR design.

While no RMWRs have been built to date, the concept remains an active area of research in the field of nuclear engineering. Future developments in reactor design and materials science could potentially overcome the challenges associated with the RMWR and make it a viable option for future nuclear power generation.

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