Dakota67,
I'm glad you've pulled back on the tone of your initial post, I don't think the message here is that the RAF is deliberately turning a blind eye to risks that put the lives of their colleagues in danger.
From what I have read / heard there is a propensity for the aircraft to suffer fuel leaks in operation (partially due to a requirement of certain couplings to be aligned within 1° and the difficulty in inspecting this in the fleet). This seems to be a question of robustness, not of dispatch/ aircraft release. There is also the requirement for the aircraft (all aircraft) to be resistant to ignition should a fuel leak occur: This falls strongly into the industry efforts that no single problem should cause risk to any aircraft.
On all aircraft there are several potential ignition sources, either electrical or thermal, and engineering efforts are made to mitigate them, that is to say to reduce the risk to zero. Some are obvious, some less so (lest we forget TWA Flight 800, rest their souls). It seems that when the retrofit / upgrade of the Nimrod from MR1 to MR2 occurred a new ignition source was added in an area not immediately adjacent to the problematic pipework. This new source were the systems air conditioning pipes that were incorrectly / insufficiently lagged. This system has since been de-commissioned and the RAF is re-evaluating all the other (mainly electrical) ignition sources.
So what we have is a potential ignition source that had been identified but had been considered of insufficient risk for immediate action. For me this is an example of not so joined up thinking that is very similar to the thought process that gave a "go to launch" for an o-ring outside it's operational limit that happened to be installed in a solid rocket booster that happened to be strapped to a shuttle that happened to be strapped to several very unlucky NASA astronauts.
Groups of very interested, very intelligent, very well meaning people are capable of arriving at life threatening events by way of a series of small, seemingly unimportant, poorly judged decisions.
Not defending, not criticising and in no way based on any information that hasn't been communicated publicly, these thoughts are my personal opinion. If I am factually incorrect please correct me. My opinions should not be taken to be representative of fact or opinion from anyone I am connected with professionally. Is that a big enough disclaimer?
As a PS, there was in interesting discussion on BBC Radio 4 on this subject between Jimmy Jones (one of the Nimrod's original Flight Engineers and adviser to the victims' legal team) and Air Marshal Sir Barry Thornton (responsible for RAF Maintenance). It was pod casted here: BBC PODCAST (http://downloads.bbc.co.uk/podcasts/radio4/today/today_20080524-1024.mp3)
I'm a conscientious man... when I throw rocks at seabirds I leave no tern unstoned. (Ogden Nash)
Et nom de dieu! C'est triste Orly la dimanche (Jacques Brel)