The New Scientist report that:
"YOU might think nuclear weapons have been carefully designed not to go off by accident. Yet more than 1700 of them have design flaws that could conceivably cause multiple warheads to explode one after another - an effect known as "popcorning" - according to a UK Ministry of Defence safety manual.
A typical Trident nuclear missile contains from three to six warheads, and a US submarine might carry up to 24 missiles. Weapons builders aim to prevent accidental explosions of warheads by designing them to be "single-point safe". This means that a sudden knock at a single point - say if it were dropped from a crane while being unloaded from a submarine - should not detonate the plutonium core.
However, a nuclear-weapons safety manual drawn up by the MoD's internal nuclear-weapons regulator argues that this standard single-point design might not be enough to prevent popcorning. The document was declassified last month.
The manual says that warheads should be capable of resisting multiple simultaneous impacts. This "would contribute to the prevention of popcorning and should be a design objective".
It also recommends replacing the highly sensitive explosive that surrounds the warheads' plutonium cores. A single knock may not detonate the core, but could set off this explosive. Less-sensitive explosives are available, but they are heavier and bulkier than those currently in use, so the warheads would have to be redesigned.
The effects of a popcorning accident would be dire. According to the manual, in the worst-case scenario, people a kilometre away would receive a radiation dose of 100 sieverts - that's 16 times the lethal dose. The seriousness of the accident would depend on the pattern of warhead explosions, though."
Read the rest and start worrying, or not!
No comments:
Post a Comment