Our Guy in Russia: The Road to Chernobyl (Channel 4, 9pm)

What is it about Guy Martin that makes him so watchable?

That's actually a pretty simple question to answer - it's the fact he's so down to Earth. Martin has no airs and graces; what you see is what you get. Even his official website claims that if you called on him at his home in Kirmington, East Yorkshire, you would meet exactly the same Guy who pops up on our screens - and in an age of superslick presentation and over-scripted soundbites, that's very refreshing indeed.

He's a sort of accidental TV star too, giving viewers the impression that they, too, could follow in his footsteps.

Born in Grimsby in 1981 - and named after Wing Commander Guy Gibson, leader of the Dambusters, who had been stationed nearby during the Second World War - and began racing motorcycles seriously at the age of 17 and has had 17 podium finishes at Isle of Man TT events.

Racing is in his blood - his father Ian also enjoyed success on the Isle of Man, but supplemented his income as a lorry mechanic; his son would eventually follow in his footsteps. As Martin has been obsessed with engines since he was 12, it was a natural step.

His move into TV began in 2009 when he was filmed for an ITV4 programme about that year's TT race. Additional footage was shown to a BBC executive who was so impressed that he signed him to present 2011's The Boat That Guy Built, which focused on his love for engineering rather than adrenalin-driven sport.

These days he's a regular face on Channel 4 thanks to such programmes as How Britain Worked, Speed with Guy Martin and now Our Guy in Russia.

This week's episode of his travelogue, however, sees Martin leave Russia and journey to one of its neighbours, Ukraine. He wants to see the true horror of Chernobyl, site of the biggest nuclear disaster in history, and where record-breaking engineering solutions are being used to make the area safe, 32 years after the local power station exploded.

Martin receives special training in avoiding contamination before being allowed in the Earth's most radioactive place - a restricted exclusion zone of 1,000 square miles which contains, at its centre, the breached reactor, now entombed in a 36,000 tonne shelter.

Amazingly, during a radiation survey, he discovers that levels are so high, he can only stay for 20 seconds without endangering himself.

Martin also meets a surviving 'liquidator', one of a group of volunteers who, in the immediate aftermath of the disaster, helped with the clean-up while wearing makeshift protective clothing made from lead, while a grandmother who returned to her home against all advice and the security guards desperately trying to stop thieves stealing scrap metal from the area tell of their experiences.

All their stories a jaw-droppingly amazing - and for once, the presenter himself may be left lost for words.

Lorry Ladies (BBC1, Regions Vary)

Angela Rippon is a trailblazer. Back in the 1970s, she became the first woman to regularly present the news for the BBC. As a result, her fame transcended her day job and she popped up on numerous other programmes, even showing off her previously unknown dance talents to great effect alongside Eric and Ernie on the 1976 Morecambe and Wise Christmas Show. Now she's meeting fellow trailblazers, albeit of a different kind. Female lorry drivers aren't exactly unheard of, but those she interviews during a trip to Northern Ireland have taken the profession to a new level. Here they talk about their passion for the open road and why, after a long week behind the wheel, like nothing better than attending truck festivals across the country.

Nadiya's Family Favourites (BBC2, 8pm)

Former Great British Bake Off winner Nadiya Hussain demonstrates dishes for those times when it seems there is nothing in the house to eat, using leftovers and kitchen cupboard staples to make fruit salad fattoush, ginger rice with spicy chickpeas, avocado pasta with peas and mint, and carrot cake pakoras with a cream cheese dip. Meanwhile, her quest to find the best home-made pasta in Britain takes her to Derby, and her love of all things spicy lands her in a herb garden with spice expert Roopa.

The Bermuda Triangle Enigma: Fallen from the Sky (C5, 9pm)

If you were planning a programme about mysterious, unexplained events, who would you get to present it? Perhaps Professor Brian Cox or someone else of that ilk. Channel 5, however, are clearly opting for a more lowbrow approach to the subject because it's Rick Edwards and Ortis Deley who are taking charge of this three-part documentary. They want to know more about the Bermuda Triangle, a place that, legend suggests, is the centre for a series bizarre events. Are conspiracy theorists right, is there really something strange happening there, or are they all just bound together by coincidence? Deley hopes to find out in Florida, where he investigates the disappearance of five naval aircraft in 1945, while Edwards dives beneath Bermuda's waves to see if the wreck of a 1963 US Air Force plane holds any clues.