Reactors using heavy water as their moderator have a number of advantages due to their improved neutron economy.

In conceptual terms, CVTR is very similar to the CANDU reactor design that was being pursued by Atomic Energy of Canada Limited around the same time.

CVTR is otherwise similar in most respects, and about the same size and power as the 22 MWe CANDU prototype which entered service in 1962.

The water is held under pressure in order to increase its boiling point, which makes the turbines more efficient.

For one, the water not only acts as the cooling fluid, but also as the neutron moderator, which means its control is vital to the operation of the system as a whole.

Additionally, the water tends to pick up radioactivity from the reactor's operation, which leads to safety concerns and maintenance overhead.

The major advantage to the light water design concept is that it is simple and similar to existing systems in many ways.

This is enough of an effect that there are not enough neutrons of the right energy to maintain the chain reaction in natural uranium fuel.

This requires such designs to use enriched uranium to offset this effect, which increases the price of fuel.

Using natural uranium in a reactor would offer the advantage of lowered fuel costs and better availability as the supply is not dependent on the enrichment cycle.

The entire interior of the containment building was lined with an airtight layer of welded steel plates 1/2" or 1/4" thick, depending on location.

[2] The site for the CVTR was approved by the Atomic Energy Commission’s Advisory Committee on Reactor Safeguards in January 1959.

[2] Staff: Following decommissioning of the CVTR, the facility was used for conducting large scale tests to provide experimental information on the response of containment structures to severe events.