CHAPTER FIVE
TRANSITION TO NUCLEAR
September 1973
Prime Minister – Still Edward Heath
The UK joins the European Union
Top of the Pops – ‘Daydream’ – David Cassidy
Average UK House price – £9,942
New OED words – UNIX, date-rape, petro-dollar
I was to stay with HMS Orpheus until she de-commissioned in August 1973 and then it was time to ‘go nuclear’ but first I was to do the specialist submarine Navigation course at the navigation school – HMS Dryad (on top of Portsdown Hill). This was a relatively short course (two months) but very intensive. There were six of us on the course and it culminated on-board a frigate in which, over the next four days, we sailed round and round the Isle of Wight each taking it in turns to be the navigator. We had to work out all the tidal streams and currents well in advance and then proceed to pre-determined buoys or anchorages with precision and exact timing. Very useful skills for a submariner.
I then went off to the Royal Naval College at Greenwich to do the nuclear course – principally to learn, in some detail, how a pressurised water reactor (PWR) worked together with all the necessary supporting systems. The PWR was of course the power source in each of the nuclear submarines. Greenwich was rather an odd place to have the nuclear school; however, I guess it was an available and convenient location at the time. We particularly enjoyed the Monday to Friday, 9 till 5 routines – and dining in the great Painted Hall was a joy. I wonder how many of the good citizens of Greenwich realised that one of the buildings housed a low power nuclear reactor (called ‘Jason’). It was a pretty testing course for those who did not have a scientific or mathematical bent – and there was an exam at the end but I am not sure if anyone ever failed.
How the PWR works.
The pressurised water reactor was the power source for UK nuclear submarines. I thus go on to describe, in as simple terms as I can, how the PWR works because I think many readers will be interested – but if you are not interested then please skip to the next section.
The fuel for a pressurised water nuclear reactor was uranium. Uranium is a very dense metal (70% denser than lead) and it occurs naturally in two forms – the most common form (99.3%) being U238 so called because its nucleus contains 92 protons and 146 neutrons (92 + 146 = 238). But there is another variant uranium (U235 – 0.7%) that has just 143 neutrons in the nucleus. This variant is unstable and has the tendency to ‘throw off’ the occasional neutron. If that migrant neutron were to hit another nucleus then that nucleus would split into two lesser elements (krypton and barium) and in so doing some ‘binding energy’ would be released in the form of heat – this process is known as fission. The fission process also gives rise to gamma radiation – which is not good for humans. ‘Gamma’ radiation is a ‘non-particulate’ radiation i.e. a sort of radio-wave/microwave type radiation. In strong doses, like sunshine and the consequent sunburn, it can kill you.
In order to build a fission reactor, the uranium fuel has to be ‘enriched’ so that it has a much higher percentage of the unstable U235; and this enrichment takes place in specially designed centrifuges. The enriched uranium is then formed into ‘rods’ that are coated with corrosion resistant metal called zirconium. These fuel rods are then placed inside the reactor vessel. In order to give the migrant neutrons (the ones that are periodically ‘thrown off’) the best chance of hitting another nucleus and causing fission they have to be slowed down by a ‘moderator’; and in the case of the pressurised water reactor this moderator is water – hence the name. The fission process has to be controlled and thus, interspersed amongst the fuel rods, are ‘control rods’ and these are made of another metal – hafnium. Hafnium has the property of absorbing migrant neutrons and so, with the control rods fully inserted, the reactor is inert. In order to begin the reaction, the hafnium control rods are slowly and carefully withdrawn from the reactor pressure vessel until fission begins. As soon as fission begins heat is generated and this is ‘captured’ by a primary coolant – i.e. the water (that also acts as the moderator). The water is pumped through the reactor pressure vessel and out into a pipe-work ‘loop’ by primary coolant pumps and, on its way, it passes through a ‘steam generator’ which does exactly as it says on the tin – it generates steam; as the ‘loop’ curls its way through the steam generator it acts in exactly the same way as the elements in your kettle. The steam is drawn off and in so doing it cools the water in the loops. In a submarine, the whole of the aforesaid system is contained within a reactor compartment – an immensely strong sealed compartment lined with ‘boronated’ polythene blocks that absorb the gamma radiation.
A simple diagram and dimensions needed
The steam drawn off is used to drive two main engines that are linked together by a gear box to a single propeller shaft. The steam also drives two turbo generators that produce electricity for the multitude of other systems within the submarine. So, the nuclear reactor is basically a ‘kettle’ that generates heat which in turn generates steam and everything else ‘downstream’ is steam driven. However, in order to get the necessary power required by a submarine, the system operates at very high temperatures and pressures – the primary loop operates at about 450 degrees C and 750 psi. Notwithstanding these temperatures and pressures, the propulsion system and electricity generating system were basic steam driven devices. Not a lot different from a Victorian railway engine. If Thomas Newcomen or James Watt were shown round the propulsion and generating systems of a nuclear submarine then, although they would have been in awe of the engineering standards, they would have understood the principles. However, they would have no understanding whatsoever, of the heat-generating reactor. The ‘atomic’ theory began to evolve in the early 19th century but it was not until the turn of the 20th century that clearer understanding began.
The beauty of the PWR is that is entirely self-regulating. If the submarine wants to go faster then the propulsion panel operator opens the throttles to allow more steam into the engines. As more steam is drawn off then the cooling effect on the primary loop, as it passes through the steam generators increases – the colder (and hence denser) water is then more effective as a moderator and so fission in the reactor increases and more heat is generated and vice versa – you don’t have to touch a thing! As time goes by more and more of the U 235 in the fuel rods is expended and to compensate for this the hafnium control rods are gradually withdrawn further. But this is a gradual process – the earlier reactors could power the submarines for about four years before re-fuelling was necessary. Later reactors increased this to 10 to 12 years. Just as an aside, for safety reasons, the hafnium control rods (the safety police) were held in place within the reactor vessel by very powerful mechanical springs – to withdraw the rods they had to be actively driven out and held out against the force of the springs by electric motors. If there were to be an electrical failure then the rods would immediately be plunged down by the springs and the reactor would shut down. This safety feature, and a number of others, could be over-ridden by a ‘battle short’ switch – more on this later.
In the UK, the reactors were built by Rolls Royce and Associates. On commissioning, each submarine was presented with a ‘Spirit of Ecstasy’ (the flying lady on the bonnet of Rolls Royce cars) . The car versions were made of chromium plated steel – but the submarine versions were made of hafnium! Hafnium was more expensive than gold.
The pressurised water reactor proved to be an incredibly reliable and resilient power source. We were all given a very deep and detailed understanding of this during our Greenwich Course. We went on to go to sea in submarines powered by a PWR, often in very dangerous places and in situations where loss of power could prove terminal to the crew. But we had complete faith in the technology and had no qualms about it at all.
It was often very irritating to come across the many opponents to nuclear power, particularly in the early years of the 70s. Many of these opponents had no technical understanding of nuclear science and technology. I should point out that the science behind a nuclear power generator and a nuclear bomb is entirely different but these people could not discern the difference. A nuclear power generator cannot become a ‘bomb’ – fact, full stop. I will explain more about bombs later in this book. In some ways it is the ignorance and intransigence of these people that has brought about much of today’s carbon crisis.
The development of nuclear submarines
The first fission ‘nuclear’ reactor was built by a team, led by Fermi, in Chicago, USA, in 1942 and the science and technology gained through this project led to the creation of a number of designs for electrical power generating reactors. As I have already said but I will repeat it – the technology behind a fission reactor designed to generate power is very different to that of a fission ‘bomb’. I will not go into detail but please understand that there is no comparison at all – the technology divides and proceeds down two separate paths. A pressurised water fission reactor generating electric power cannot be turned into a bomb!
The first ‘pressurised water’ Nuclear reactor was developed in the late 1940’s specifically for the purpose of providing power to a nuclear submarine. The first ‘nuclear’ powered submarine was the USS Nautilus, launched in 1952 and commissioned in 1954 and went to sea for the first time in 1955. The first Commanding Officer was Commander Eugene P Wilkinson who famously signalled on 17th January 1955 ‘underway on nuclear power’. Remarkably, Nautilus remained in commission until 1980 and she is now on display as a ‘museum’ piece in the US Naval Base in New London.
Since 1954 submarine technology began to move ahead at a furious pace spurred on by a growing arms race with the Soviet Union. The first Soviet nuclear submarine was the ‘Hotel’ Class (Hotel being the NATO designator given to the first of this class). The first of class (soviet designated number K 19) was commissioned in 1960 and went to sea, for the first time in 1961. However, the history of this submarine was frightening – she had been built in a hurry as a determined attempt to catch up with the US and the design and build standards were appalling by western standards. Ten civilian construction workers died during build as a result of fires and other accidents. Early in her commission K 19 suffered a complete loss of ‘cooling’ to the reactor core and , because of corner-cutting and design ‘haste’, there was no back up. To avoid what inevitably would have led to core-meltdown the engineering team managed to construct a make-shift cooling system but at great cost to human life from gamma radiation exposure. Eight crew members died within three weeks of the accident and a further 14 died over the ensuing 2 years.
To add insult to injury K19 later collided with a US spy submarine (the USS Gato) in the Barents Sea and was severely damaged although she was able to return to port for repair. USS Gato was relatively undamaged and continued her patrol.
Then in 1972, whilst on patrol off the western seaboard of the United States a serious fire broke out onboard K19 (thought to be the outcome of a high-pressure hydraulic system pipe burst). The submarine was forced to surface and most of the crew were evacuated to safety on board another Soviet conventional submarine. K19 refused offers of assistance from the US Navy and it was then a further 40 days before the situation was brought under control and the K19 was towed back to …. For repair.
This whole event was the subject of a movie – K19 the Widowmaker- starring Harrison Ford and Liam Neelson
Remarkably, K19 remained in commission until 1990 and was sent to scrap in 1994. The Soviet millionaire Vladimir Romanov (who had served on K19 as a conscript) bought a section of the hull with the intention of bringing it back to Moscow and turning into a meeting place . Romanov’s vision never came into being, although he did go on to buy the Heart of Midlothian Football Club in Edinburgh which in turn ‘Mad Vlad’ nearly drove into administration.
At the time of writing Vladimir Romanov is broke and has been charged with bank fraud. He lives in the hull section of K19 which he bought and this lies in a village called Nikulskaya some 450 miles north of Moscow.
I mention the sorry tale of K19 because it epitomises the requirements to keep a submarine safe. Every submariner sets out to ensure that the number of dives always equals the number of surfaces and to achieve this requires;
- The best possible submarine design
- The best and most appropriate materials
- Skilled and diligent construction
- Testing at every stage
- Thorough crew training at every level and every stage
- Due diligence and care in every action
- Internal and external communication
- Teamwork
Take any one of these away and your submarine is standing into danger. In the case of K19, numbers one through five were lacking – I cannot comment on six through eight but I suspect that they too were lacking.
We were (and still are) very fortunate that through close co-operation with the US Navy, the due diligence exercised by the UK Chief Polaris Executive (later Chief of Strategic Systems Executive) combined with the Sea Training Organisation and our Squadron System of management the Royal Navy ticked all the above boxes.
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