Secret MoD manual acknowledges risks posed by Trident missile fuel

Information from a Royal Navy whistleblower has confirmed that the dangers from an accident involving a Trident nuclear weapon are more serious than the Ministry of Defence has said publicly.

William McNeilly, a submarine engineering technician who has published a damning account of faulty equipment and poor safety practice during a patrol on HMS Vanguard, on the the Royal Navy's Trident submarines, has quoted material from a top secret Ministry of Defence safety manual which outlines a number of accident scenarios which could cause a nuclear warhead to catch fire or release radioactive material.

The information is from MoD's instruction document 'CB8890: The instructions for the safety and security of the Trident II D5 strategic weapon system' – a key set of guidelines on which Royal Navy personnel doing 'hands on' work with Trident missiles and warheads are required to sit a proficiency exam.

McNeilly's account gives the following direct quotes from the CB8890 manual, which says he filmed on board HMS Vanguard using a smart phone:


Paragraph 0214 – If the HE [high explosive] charge is exposed to excessive heat without burning, it may become more sensitive and could cook to (non-nuclear) detonation, releasing radioactive materials and aerosols over a wide area.

Paragraph 0215 – If RB [re-entry body] containment is breached, several radioactive and/or toxic materials may be exposed to the atmosphere. These include plutonium, uranium, lithium compounds, tritium gas and beryllium. If mixed with water, fumes or toxic gases will be generated. When installed in a Trident II D5 missile, RBs clustered around the Third Stage Rocket Motor are at risk from a rocket motor propellant fire.

Paragraph 0216 – The RB could become physically damaged due to collision or fire in peacetime and in war could be subjected to splinter attack or the effects of detonation from enemy projectiles. This type of damage could also result from a successful terrorist attack.

Paragraph 0217 – An accident or enemy action may cause rupture of the RB, burning or possible detonation of the HE and release of radioactive contamination. 

Paragraph 0219 – The chief potential hazard associated with a live missile is the accidental ignition of the first, second or third stage rocket motor propellant. If this were to happen in the missile tube with the muzzle hatch shut and locked, the pressure hull and bulkheads of the MC [missile compartment] would burst within a matter of seconds. In addition the missile contains a number of subsidiary propulsive and ordnance items that could cause damage to the missile and/or release toxic gases into the MC if initiated prematurely. In some cases, this could also result in ignition or detonation of one of the rocket motors.


The excerpts confirm a particular safety concern about the Trident D5 missile which have been highlighted by independent analysts but downplayed by the MoD.  They acknowledge that warheads loaded onto a missile are at risk from a fire involving rocket motor propellant.  The missile's third stage rocket motor poses a particular threat because it is in close proximity to the warheads and not physically separated from them.

This issue was raised as a concern in 1990 in the USA by the Drell Report – a report to the US House Armed Services Committee from a panel of experts under Dr Sidney Drell on the safety of US nuclear weapons.  Following Drell's report a similar review took place in the UK chaired by Professor Sir Ron Oxburgh, at the time MOD's Chief Scientific Adviser.  In contrast to the Drell panel, Oxburgh found no evidence to suggest that in-service or planned UK weapons required any significant redesign. Specifically discussing the Trident system, the working group concluded that Trident safety levels would be "comparable to and in some ways higher than those associated with the Polaris system", glossing over the third stage rocket motor issue.

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