The most striking thing about any plane journey is the number of people who bless themselves as the aircraft takes off and the gasps of horror that follow whenever it shudders through a spot of turbulence.
Sellafield has a similar effect on a first-time visitor. Nuclear fuel may be more environmentally friendly than coal and oil in many ways, and it may be more than 40 years since there has been a really serious accident at Sellafield. BNFL also goes to extraordinary lengths to protect visitors from harm. Yet when you don the protective clothing and the radiation detector at the plant door, you can't help feeling slightly terrified.
Aesthetically, Sellafield is not what you might expect of hightech industries. While there are parts of the plant where "every speck of dust is accounted for", much of the complex is more reminiscent of a rusting shipyard than a place where "science never sleeps".
While proud of their work and eager to explain what they do, many workers appear bored and much of their work is dull and repetitive.
The most unnerving aspect of a plant tour is the constant "tick, tock" of the radiation monitor. Your guide warns you at the start that if the metronome rhythm ceases and the tone changes to that of the NATO warning siren "you'd better run" because that signals "a criticality incident". Little wonder some locals refer to the plant as "the bomb".
After about half an hour of the tour of the THORP (reprocessing) part of the complex, the guide says, "are you afraid?"
Having just spotted a printed notice that warned workers that a "frigged out" switch was causing a control mechanism to respond sluggishly, I wasn't exactly filled with confidence. The sign concluded: "If in doubt, stop".
Sellafield has a history of safety breaches. Since the most serious scares in the 1970s and 1980s BNFL says pollution from Sellafield has been dramatically reduced.
Emission levels are just 1 per cent of what they were in the 1970s, the company claims.
Yet one of the most bizarre safety scares occurred just two years ago. Two sisters who ran a pigeon farm at their home in Seascale had to cull all but a dozen of their 700 birds.
The pigeons had a habit of nesting and sheltering in the disused chimneys of Sellafield, and then coming to feed in Jane and Barrie Robinson's garden. However, when the birds were tested they were found to be radioactive. When one died it had to be classified as nuclear waste.
Six inches of soil were dug up from the Robinsons' garden and dumped in a nearby nuclear waste tip because of contamination by radioactive pigeon droppings.
While other more serious accidents have contaminated the Cumbrian coast or exposed BNFL employees to unacceptable levels of radiations, the most recent sca re in the mixed oxide fuel (MOX) plant has potentially the most far-reaching implications yet for the long-term prospects of reprocessing continuing at Sellafield.
The waste generated is stored at Sellafield for eventual return to its country of origin. The MOX fuel comes out at the end of the process in pellet form.
It was a manual re-check of the diameter of a sample of those pellets that the workers at the MOX plant were caught skipping, causing a crisis of confidence among foreign customers. While BNFL says skipping the check was inexcusable, the company sees the issue as one of quality control rather than safety, as there are five other direct or indirect checks of the diameter of the pellets.
The convenor of the GMB union at the plant, Mr John Kane, said: "The process that the individuals were undertaking was a four-stage process. With previous customers it had been a three-stage process and they'd been used to working that way.
"As a union, we can't condone what happened. But there was no malice on the part of the individuals involved in this and there was no safety issue."
While management and staff are at one on most safety issues, there is one on which they disagree. BNFL has been shedding staff in preparation for partial privatisation and Mr Kane says this has implications for safety.
"BNFL want to say to the outside world, `we're a lean fit organisation'. I believe the company made a mistake by purely going for a head count. I think the structure should have been in place first to meet the business needs. I believe we got rid of far too many [staff] far too early."
He says the workers at the MOX demonstration plant "were really pushed. They wouldn't have compromised safety but they saw that [skipping the extra diameter check] as a way of having more time to spend on other roles they have to carry out within the plant". Mr Arthur Roberts, the deputy head of the Sellafield site, says the question of staffing levels is something BNFL must address.
"This is hopefully an isolated incident where individuals for whatever reason chose not to do something and I couldn't condone that for a minute."