Operational considerations for commercial nuclear propulsion

 September 6, 2021

Known to most as a senior London arbitrator, Michael Allen’s first career before becoming a lawyer was as an engineer officer on British nuclear submarines. Below, he poses plenty of questions about crew onboard the next generation of nuclear-powered ships.

There is increasing activity towards the advent of commercial nuclear propulsion, focussing on the molten salt reactor (MSR) instead of the pressurised water reactor (PWR).

Seagoing experience for the past 70 years or so, commencing with USS Nautilus, has been with PWRs. As a result of the close co-operation between Lord Mountbatten and Admiral Rickover, the Royal Navy’s first nuclear submarine, HMS Dreadnought, was launched on Trafalgar day, October 21 1960. Dreadnought was in fact an American Skipjack class design with a British front end and a US reactor and machinery configuration. Going aft, there was a sign “Checkpoint Charlie, you are now entering the American sector”.

The design and build of full size MSRs may prove to be easier than providing fully trained operators

Thereafter, the Royal Navy built nuclear submarines to a national design but RN/USN exchanges, not only technical but also operational, had been an essential part of gaining PWR experience.

At its very simplest, the reactor is the heat source which boils the water which generates the steam which propels the turbines which drive the vessel and the generators which provide electrical power. Of course, it is very much more complex than that and, for commercial shipping, revolutionary, not evolutionary. It is therefore essential that the watchkeepers fully understand the plant they are looking after but they will have no previous experience to draw on.

There are advantages of MSRs over PWRs, lower pressure, higher temperature, primary pump flow rate control, less risk of meltdown but the training of PWR operators gives some insight into what may be required for MSRs. This has been broadly divided between the theoretical and the practical.

The theoretical has generally taken place by way of post graduate academic study of nuclear physics for officers and similar courses for senior ratings. Whilst the MSR differs from the PWR, presumably such theoretical nuclear physics education will have to be provided. For example, will operators need a thorough understanding of molten salt treatment similar to that required for reactor water chemistry in a PWR?

The practical training may be a more difficult issue to address.

There are numerous operating issues which simply cannot be rehearsed and practiced at sea. Accordingly, simulator training plays a major role in, as far as possible, ensuring safety, very much in the same way as it does in the aircraft industry. It is important for effective simulator training that the participants feel that they are sitting in the real thing, such as a cockpit or a submarine manoeuvring room, even though they are firmly on the ground.

Whilst the theoretical study will most likely be a one off, simulator training should continue ashore for as long as the watchkeepers are employed. This is particularly important given the potential monotony of watchkeeping when the vessel is on passage at a steady speed with very little happening. The unexpected will occur and watchkeepers have to react instantly and correctly. Emergency operating procedures have to be second nature.

Nuclear propulsion training and operation is a different matter for armed services than for commercial operators but safety is fundamental for both. Not only would shipowners be entering a new era, so would their insurers, both H&M and P&I, as well as classification societies and flag states. Every party needs to be confident that crews have been trained as thoroughly as possible. This raises more issues; where will the first crews be recruited from and who will have the necessary operational experience to train them? Will they seek a higher rate of pay than currently on offer? Will the operational training have to take place on the first vessel built and how long will that take? Will commercial operators invest in simulator training? Will it be required by their insurers as a condition precedent for cover? Will there be a requirement for regular third party (flag, class) inspection of watchkeepers to ensure that they are and remain fully trained? Will it be necessary to have a modified form of training for the Master and bridge watchkeepers to fully understand what is going on below?

The design and build of full size MSRs may prove to be easier than providing fully trained operators.