Rolls-Royce PWR
Encyclopedia
The Rolls-Royce
pressurised water reactor (PWR) series has powered British nuclear submarine
s since the Valiant class
, commissioned in 1966. The first British nuclear submarine, HMS Dreadnought
, was powered by a Westinghouse S5W reactor
.
The first British naval reactor, the PWR1, utilising a core
based on a Westinghouse design (though built entirely by Rolls-Royce) and a larger reactor assembly of purely British design went critical
in 1965. Technology transfers under the 1958 US-UK Mutual Defence Agreement
eventually made Rolls-Royce entirely self-sufficient in reactor design in exchange for a "considerable amount" of information regarding submarine design and quietening techniques being passed on to the USA.
Rolls Royce and Associates at Derby
became the centre for design and manufacture of the reactors. The Ministry of Defence
's Vulcan Naval Reactor Test Establishment, at Dounreay
, tested each reactor prior to its installation in nuclear submarines.
designed to power the Royal Navy
's submarines. The PWR2 was developed for the Vanguard-class
Trident missile
submarines and is a development of the PWR1. The first PWR2 reactor was completed in 1985 with testing beginning in August 1987 at the Vulcan Naval Reactor Test Establishment.
The latest design of the PWR2 is the "Core H", which removes the need for refuelling, allowing a submarine to avoid two reactor refits in its service life. HMS Vanguard will be fitted with the new core during its refit, followed by its three sister ships. The s will have this full-life core installed. As they were developed for SSBN
s, the reactors are considerably larger than those of current British SSNs. The diameter of Astute class hulls have therefore been increased to accommodate the PWR2.
Rolls-Royce Marine Power Operations Ltd
claim that the Core H PWR2 can deliver six times the power of the original PWR1 and last four times as long.
request. The Regulator identified two major areas where UK practice fell significantly short of comparable good practice, loss-of-coolant accident and control of submarine depth following emergency reactor shutdown. For the British replacement of the Trident system
the option of developing a PWR3 plant based on current US design was under consideration, and in March 2011 Defence Secretary Liam Fox
indicated this was the preferred option "because those reactors give us a better safety outlook".
In May 2011 the Ministry of Defence
announced that the US design had been selected for the PWR3, at a cost of about £3 billion.
Rolls-Royce plc
Rolls-Royce Group plc is a global power systems company headquartered in the City of Westminster, London, United Kingdom. It is the world’s second-largest maker of aircraft engines , and also has major businesses in the marine propulsion and energy sectors. Through its defence-related activities...
pressurised water reactor (PWR) series has powered British nuclear submarine
Nuclear submarine
A nuclear submarine is a submarine powered by a nuclear reactor . The performance advantages of nuclear submarines over "conventional" submarines are considerable: nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for...
s since the Valiant class
Valiant class submarine
The Valiant class were a class of nuclear-powered fleet submarines in service with the Royal Navy from the mid 1960s until 1994. They were the first fully British nuclear fleet submarine; the earlier used an American nuclear reactor...
, commissioned in 1966. The first British nuclear submarine, HMS Dreadnought
HMS Dreadnought (S101)
The seventh HMS Dreadnought was the United Kingdom's first nuclear-powered submarine, built by Vickers Armstrongs at Barrow-in-Furness. Launched by Queen Elizabeth II on Trafalgar Day 1960 and commissioned into service with the Royal Navy in April 1963, she continued in service until 1980...
, was powered by a Westinghouse S5W reactor
S5W reactor
The S5W reactor is a nuclear reactor used by the United States Navy to provide electricity generation and propulsion on warships. The S5W designation stands for:* S = Submarine platform* 5 = Fifth generation core designed by the contractor...
.
PWR1
Nuclear reactor core
A nuclear reactor core is the portion of a nuclear reactor containing the nuclear fuel components where the nuclear reactions take place.- Description :...
based on a Westinghouse design (though built entirely by Rolls-Royce) and a larger reactor assembly of purely British design went critical
Critical mass
A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The...
in 1965. Technology transfers under the 1958 US-UK Mutual Defence Agreement
1958 US-UK Mutual Defence Agreement
The 1958 US–UK Mutual Defence Agreement is a bilateral treaty between the United States and the United Kingdom on nuclear weapons cooperation.It was signed after the UK successfully tested its first hydrogen bomb during Operation Grapple. While the U.S...
eventually made Rolls-Royce entirely self-sufficient in reactor design in exchange for a "considerable amount" of information regarding submarine design and quietening techniques being passed on to the USA.
Rolls Royce and Associates at Derby
Derby
Derby , is a city and unitary authority in the East Midlands region of England. It lies upon the banks of the River Derwent and is located in the south of the ceremonial county of Derbyshire. In the 2001 census, the population of the city was 233,700, whilst that of the Derby Urban Area was 229,407...
became the centre for design and manufacture of the reactors. The Ministry of Defence
Ministry of Defence (United Kingdom)
The Ministry of Defence is the United Kingdom government department responsible for implementation of government defence policy and is the headquarters of the British Armed Forces....
's Vulcan Naval Reactor Test Establishment, at Dounreay
Dounreay
Dounreay is the site of several nuclear research establishments located on the north coast of Caithness, in the Highland area of Scotland...
, tested each reactor prior to its installation in nuclear submarines.
PWR1 submarines
- Core 1
- 2 Valiant classValiant class submarineThe Valiant class were a class of nuclear-powered fleet submarines in service with the Royal Navy from the mid 1960s until 1994. They were the first fully British nuclear fleet submarine; the earlier used an American nuclear reactor...
- 4 Resolution classResolution class submarineThe Resolution-class submarine armed with the Polaris missile was the United Kingdom's primary nuclear deterrent from the late 1960s to 1994, when they were replaced by the Vanguard-class submarine carrying the Trident II.-Background:...
- 2 Valiant class
- Core 2
- 3 Churchill classChurchill class submarineThe three Improved Valiant class submarines, sometimes known as the Churchill class, were nuclear powered fleet submarines which served with the Royal Navy from the 1970s until the early 1990s...
- 3 Churchill class
- Core 3
- 6 Swiftsure classSwiftsure class submarineThe Swiftsure class were a class of nuclear-powered fleet submarines in service with the Royal Navy from the early 1970s until 2010....
- 7 Trafalgar classTrafalgar class submarineThe Trafalgar class is a class of nuclear-powered fleet submarines in service with the Royal Navy. They are a direct follow on from the Swiftsure class and were, until the introduction of the Astute class, the Royal Navy's most advanced nuclear fleet submarines.Seven boats were built and...
- 6 Swiftsure class
PWR2
PWR2 is the latest nuclear reactorNuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
designed to power the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
's submarines. The PWR2 was developed for the Vanguard-class
Vanguard class submarine
The Vanguard class are the Royal Navy's current nuclear ballistic missile submarines , each armed with up to 16 Trident II Submarine-launched ballistic missiles...
Trident missile
Trident missile
The Trident missile is a submarine-launched ballistic missile equipped with multiple independently-targetable reentry vehicles . The Fleet Ballistic Missile is armed with nuclear warheads and is launched from nuclear-powered ballistic missile submarines . Trident missiles are carried by fourteen...
submarines and is a development of the PWR1. The first PWR2 reactor was completed in 1985 with testing beginning in August 1987 at the Vulcan Naval Reactor Test Establishment.
The latest design of the PWR2 is the "Core H", which removes the need for refuelling, allowing a submarine to avoid two reactor refits in its service life. HMS Vanguard will be fitted with the new core during its refit, followed by its three sister ships. The s will have this full-life core installed. As they were developed for SSBN
Ballistic missile submarine
A ballistic missile submarine is a submarine equipped to launch ballistic missiles .-Description:Ballistic missile submarines are larger than any other type of submarine, in order to accommodate SLBMs such as the Russian R-29 or the American Trident...
s, the reactors are considerably larger than those of current British SSNs. The diameter of Astute class hulls have therefore been increased to accommodate the PWR2.
Rolls-Royce Marine Power Operations Ltd
Rolls-Royce Marine Power Operations Ltd
Rolls-Royce Marine Power Operations Limited, a subsidiary of Rolls-Royce plc, operates three nuclear licensed sites, two of which are at Raynesway in Derby, UK....
claim that the Core H PWR2 can deliver six times the power of the original PWR1 and last four times as long.
PWR2 submarines
- 4 Vanguard classVanguard class submarineThe Vanguard class are the Royal Navy's current nuclear ballistic missile submarines , each armed with up to 16 Trident II Submarine-launched ballistic missiles...
- 4 Astute classAstute class submarineThe Astute-class is the latest class of nuclear-powered fleet submarines in service with the Royal Navy. The class sets a new standard for the Royal Navy in terms of weapons load, communication facilities and stealth. The boats are being constructed by BAE Systems Submarine Solutions at...
PWR3 options
In March 2011 a safety assessment of the PWR2 design, by the Defence Nuclear Safety Regulator in November 2009, was released under a Freedom of InformationFreedom of Information Act 2000
The Freedom of Information Act 2000 is an Act of Parliament of the Parliament of the United Kingdom that creates a public "right of access" to information held by public authorities. It is the implementation of freedom of information legislation in the United Kingdom on a national level...
request. The Regulator identified two major areas where UK practice fell significantly short of comparable good practice, loss-of-coolant accident and control of submarine depth following emergency reactor shutdown. For the British replacement of the Trident system
British replacement of the Trident system
The British replacement of Trident is a proposal to replace the existing Vanguard class of four Trident ballistic-missile armed submarines with a new class designed to continue a nuclear deterrent after the current boats reach the end of their service lives...
the option of developing a PWR3 plant based on current US design was under consideration, and in March 2011 Defence Secretary Liam Fox
Liam Fox
Liam Fox MP is a British Conservative politician, Member of Parliament for North Somerset, and former Secretary of State for Defence....
indicated this was the preferred option "because those reactors give us a better safety outlook".
In May 2011 the Ministry of Defence
Ministry of Defence (United Kingdom)
The Ministry of Defence is the United Kingdom government department responsible for implementation of government defence policy and is the headquarters of the British Armed Forces....
announced that the US design had been selected for the PWR3, at a cost of about £3 billion.