i've worn plenty of protective suits in my time, but they have always been to protect the environment from my body. this time, it's different. i've come to one of the most infamous locations on earth. until 2011, few people had heard of the fukushima daiichi nuclear power plant, in north—eastjapan. then, the largest earthquake in japanese history changed everything. the resulting tsunami killed more than 20,000 people and the iii—metre wave overwhelmed fukushima's flood defences. ironically, it was the power station's cooling system that was flooded, and when it shut down, the radioactive fuel rods began to overheat and melt down. they reacted with the steam around them, filling units one, two,

three and four with hydrogen gas, which then exploded. 6.5 years on, the melted radioactive fuel remains somewhere inside these buildings. humans can't go anywhere near that fuel, and so robots are being used first to try and find it, and eventually to remove it. and today, we have been given rare access to the site to help us understand just how hard thatjob is. translation: in order to work out how to decommission the reactor and remove the fuel, we have to survey and understand the state of the interior. only then will be know what kind of tools and machines we need to develop. probably the most important thing that i'm going to carry for a long time — dosimeter. it tells me how much radiation i've been exposed to.

the tokyo electric power company, tepco, is keen to show us — and, i guess, the world — just how much of the radioactive debris has now been removed and how it is now possible to walk around most of the site without too much protective clothing. but to really understand the challenge the robots face in finding and removing the melted radioactive fuel, we do need to suit up. we are going inside unit five, which is identical to the units which were wrecked by the explosions. as you can imagine, it's really hot inside these suits. it's a confusing jumble of walkways and machinery, and it's difficult to appreciate that somewhere in here is a seven—storey—high tank of water called the primary containment vessel - the pcv. and now, it's time to go right underneath the reactor. wow! they think what happens

after the meltdowns is that the molten fueljust burned through the bottom of the pcv and came down here, onto the what's known as the pedestal. that is where they think the fuel is now. it's difficult enough getting around this place on foot. now, imagine trying to remote control a robot through this after the whole place has been mangled by an explosion. oh, yes — and do it in the dark. each of the reactors suffered different damage. some are still full of water, some are dry, and so toshiba has built a special robot for each one. as important as how they move about is how they get in in the first place. translation: we needed something that could fit through an existing service hatch — that is the reason why we made small robots. this is scorpion.

its mission was to hunt for fuel in unit two. now, time is of the essence for any fukushima robot. the radiation will eventually damage and disable its cameras, rendering it useless. but the entire mission can also be upset by something far more basic. this is service hatch x6 and in unit two, they were hoping to send the scorpion robot down this ramp, to film the molten fuel at the bottom, but it got caught halfway down and never made it, so they didn't get any footage or any evidence of where the fuel was. in unit three, the water's much higher. so they had to think of another way to get a robot in to film what was going on. and that's where the mini sunfish came in. well, actually, that's where the mini sunfish came in. built to fit through this is—centimetre pipe, mini sunfish is a tiny underwater robot with five propellers, two cameras, and four human operators.

300km away from fukushima, in toshiba's yokohama r&d centre, i came face—to—face with the star of the investigation. after two months of practice in a duplicate of the flooded pedestal, injuly this year, mini sunfish was successful in finding molten clumps of material that could be fuel debris on the pedestal in unit three. one of the reasons there's so much water in the reactor buildings is because ground water is leaking in and it needs to be pumped out. the problem is, it can't be pumped out into the sea. so, how do you stop groundwater from leaking in in the first place? well, you build an ice wall. pipes of coolant have been inserted 30 metres into the ground and they are gradually freezing the soil and stopping anything from seeping through. it sounds completely nuts.

but how else would you do it? that is an ice wall! underground! having been criticised in the early stages, it now seems tepco is working hard to make fukushima safe. it's rebuilt and reinforced working areas, sealed the soil in concrete, and reduced radiation levels. in ourfour—hour visit, we received the radiation dose equivalent to four dental x—rays, but there is such a long way to go. decommissioning the site could take a0 years. and it may cost eight trillion yen. the human cost is more difficult to quantify. the exclusion zone has left many people homeless, unable to stop nature from reclaiming their post—apocalyptic ghost towns. they cannot go back until the radioactive fuel is recovered. those little robots have a lot

riding on their tiny backs. for the last leg of ourjapan trip, i wanted to show you something of a japanese tradition happening deep in the countryside, far away from the blade runner streets of tokyo. it's sunday morning and at this high school in the small town of tendo, dozens of pupils have gathered for a sumo match. that's robot sumo, of course. yep, today, i've come to watch a regional heat of a national competition which is now in its 25th year. and with several spots up for grabs in the final, nothing is being left to chance. the winner is the first bot to get the other one out of the ring twice. if that hasn't happened within three minutes, then the winner is the first to one point. although, if a bot flips or if it stops working, then the match is over.

or maybe they'll give them some extra time if it's really fun. you'll get the idea. they can't even push him across the floor. how is this going to work? the rings are made of steel and the sumo bots have really strong magnets to simulate the mass of real sumo wrestlers, to give them the best chance of not being flipped. but the fact that the umpires need to wear shin guards probably tells you that this doesn't always work. here we go! yeah, it's quick, and the reason is that once the bots are left alone, these matches are taking place entirely autonomously. these machines are attempting to out—think and out—sense each other in the blink of an eye. someone who knows how best to gain those little advantages

is 17—year—old amane mori. her dad came second in the very first school robot sumo competition. last year, she came third. translation: i'm trying hard to beat my father's record, that's what i'm aiming to do. he had a big influence on me. tactics include having a black bot, which is harderfor your opponent's sensors to see. the operator can also select a particular pre—programmed strategy for each bout. yes, the programming needs to be superior to win, but i think having the best blade is the most important feature. here she goes. i'm no expert, but that didn't smell good! but in the second round, amane's expertise starts to show. as the day goes on,

she conquers all before her. until, just before the final, she crashes out. there is a strategy called feint, where you back off before attacking, but the timing was off. the bot just went too early. of course, win or lose, over the years, this competition has given thousands of students invaluable experience of robotics and programming. and of course, when you do get knocked out, you can still enjoy everyone else's smash—ups! wow, what an exhilarating way to end this trip to japan! now, you'll find loads of extra photos from ourjourney on twitter @bbcclick. we also live on facebook. thanks very much for watching and we'll see you soon. things set to get livelier in parts

of uk on monday and the met office hasissued of uk on monday and the met office has issued an amber be prepared warning for strong winds, potentially disruptive across parts of northern ireland in the second pa rt of northern ireland in the second part of the day. all of course due to what is currently hurricane 0phelia, still a way to the south, but notice a stream of cloud into the northern half of the country, producing rain in parts of northern ireland, southern scotland and it turns wet here overnight and the rain pushes north. away from that, it is dry with strengthening winds in the south—west later, mild away from the north of scotland,

temperatures in the teens to start the day. this is it. the remnants of hurricane 0phelia, the longer a hurricane but still a significant storm is that bush is in the southern parts of ireland on monday, which feels the worst effects. all around these areas, the winds strengthened. rain in scotland, but when strengthening, 70 mph in the west cornwall and 70—80 around the irish sea. monday afternoon into the monday evening rush hour, the strongest winds around the irish sea coast and 70, potentially 80 mph and big disruption to ferry services and damage potentially. the rest of uk com pletely damage potentially. the rest of uk completely different. the winds from the east of scotland, chilly with outbreaks of rain. blustery for england and wales but nothing significant away from the western coasts and temperatures could hit the low to mid 20s gusty winds and the low to mid 20s gusty winds and the evening rush—hour. when with around the irish sea and the strongest winds more confined to

northern ireland, southern scotland and northern england were into tuesday, there could be problems. monday, particularly from the afternoon, through monday night, into tuesday morning, disruption as possible and even damage as well. keep up—to—date with the latest weather warnings on mine. 0n tuesday, the winds gradually ease, it stays wet. in london and wales, largely dry with sunny spells before splashes of rain in the south later. nowhere near as warm as monday afternoon across england and wales but pleasant enough in the sunshine. 0vernight rain from the south works in the northern england on wednesday and then in the summer scotland. krumins here, it was a bit warmer further south. goodbye for now. —— cooler here. this is bbc news. the headlines at seven: two more women come forward accusing producer harvey weinstein of rape. british actress lysette anthony says he attacked her in her home in the 1980s. a warning of steep rises in food prices if we leave the eu without a trade deal.

ministers insist the uk would succeed come what may. patients in england who go to see their doctor or attend a hospital appointment may be asked to declare their sexual orientation. also in the next hour — austria's exit polls put the conservative party in the lead. but 31—year—old sebastian kurz may have to go into a coalition with the anti—immigration far right party who've made big gains in the election.