The most infamous locations on earth. Until 2011, few people had heard of the fukushima eui kyung shin Nuclear Plant in north east japan. Then, the largest earthquake in japanese history japan. Then, the largest earthquake injapanese history changed everything. The resulting tsunami killed more than 20,000 people. And the 14 killed more than 20,000 people. And the 1a metre wave overwhelmed fukushimas flood defences. Ironically, it was the power stations cooling system that was flooded and when it shut down, the radioactive fuel rods began to overheat and not 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 radio fuel remains somewhere inside these buildings. Humans cant 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 today we have been given rare access to the site to help us understand just how hard the job is. Translation you have to work out how to decommission the reactor and remove the fuel, we have to survey the interior, only then will be no what kind of tools and machines we need to develop. Probably the most important thing, it tells me how much radiation ive been exposed to. The Tokyo Electric Power co 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 robot s 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 the explosions. As you can imagine, its really hot inside this. Its a confusing jumble of walkways and machinery and its difficult to appreciate that somewhere in here is a seven story high tank of water called the primary containment vessel, the pcv. And now, its time to go right underneath the reactor. While they think what happens after the meltdown is that the molten fuel just burns through the bottom of the pcv and came down here on the what is known as the pedestal. That is where they think the fuel is now. Its difficult enough getting around this place on foot. Now, imagine trying to promote 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 suffer 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 need something that could fit through an existing Service Hatch, that is the reason why we made small robots. This is scorpions, its mission was to hunt for fuel in this is scorpions, its mission was to hunt forfuel in unit this is scorpions, its mission was to hunt for fuel in unit two. This is scorpions, its mission was to hunt forfuel in unit two. Now, time is of the essence for any fukushima robot. Time is of the essence for any fu kushima robot. The 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 ex six and in unit two, they were hoping to send the scorpion robot down this ramp, to fill the molten fuel at the bottom but it got caught halfway down and never made it so they didnt get any footage or evidence of where the fuel was. In unit three the water is much higher. So they had to think of another way to get a robot in the know what was going on. That is where the fish came in. Actually, thatis where the fish came in. Actually, that is where it came in. Built to fit through this 15 centimetre pot, the fish is a tiny underwater robot with five propellers, two cameras, and four human operator. 100 kilometres away fukushima into shimas yokohama rhd centre, i came face to face with the start of the investigation. After two months of practice in a duplicate of the flooded pedestal, injuly this year the fish was successful in finding molten clumps of material that could be fuelled debris on the pedestal in unit three. 0ne be fuelled debris on the pedestal in unit three. One of the reasons there is 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 cannot 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 disloyal and stopping anything from seeping through. It sounds completely nuts. But what else would you do . That is an ice wall underground having been criticised in the early stages, it 110w criticised in the early stages, it now seems techco are working hard to make fukushima now seems techco are working hard to make fu kushima safe. Now seems techco are working hard to make fukushima safe. Its rebuilt and reinforced working areas, field disloyal and concrete and reduced radiation levels. In our four aunty visibly received the radiation dose equivalent to four dental x rays but there is such a long way to go. Decommissioning the site could take 40 decommissioning the site could take a0 yea rs. Decommissioning the site could take a0 years. And it may cost y8 trillion. 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 ducks. Backs. For the last leg of the japan trip, i wanted to show you something ofa trip, i wanted to show you something of a japanese tradition happening deepin of a japanese tradition happening deep in the countryside, far away from the blade runner streets of tokyo. Its sunday morning and that this high school in a small town of tendo, dozens of people have gathered for a sumo match. That robot sumo, of course. I have gathered to watch eight regional heat of a National Competition 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 robot to get the other one out of the ring twice and if it hasnt happened within three minutes, the winner is the first to one point although if the robot flips or stops working, then the match is over. 0r flips or stops working, then the match is over. Or maybe they will give them some extra time if it is really fu n. Give them some extra time if it is really fun. You get the idea. They cant even put him across the floor, how is this going to work . The rings are made of steel and the sumo robots have really strong magnets to simulate the mass of real sumo wrestlers to give them the best chance of not being flipped. But the fa ct chance of not being flipped. But the fact that the umpires need to wear shin guards probably tells you that this doesnt always work. Here we go its quick. And the reason is that once the robots are left alone, these matches are taking place entirely autonomously. These machines are attempting to outthink and a the job machines are attempting to outthink and a thejob in the blink of an eye. Someone who knows how best to game but little advantages is 17 year old amani mori. Her dad came second in the very first robot school competition. Last year she came third. The inflation micro trying hard to beat my father s record, it is what i am aiming to do. He had a big influence on me. Tactics include having a black robot which is harderfor your opponents senses to see, the operator can also select a particular preprogrammed strategy for each bout. Yes, the programming needs to be superior to win but i think having the best robot is the best feature. Here she goes. Im no expert but that doesnt smell good but in the second round, amane moris 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 fang twiggy back off before attacking but the timing was off. Robot went too early. Of course we all lose over the years this competition has given thousands of stu d e nts 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 elses smashed ups. What an exhilarating way to end this trip to japan. Now, you will find loads of extra photos from our journey you will find loads of extra photos from ourjourney on twitter and we also live on facebook. Thank you for watching and we will see you soon. Hello. Welcome to newswatch with me, samira ahmed. This weeks special report about heroin abuse made for hard hitting viewing, but was it right for it to lead and dominate the news at ten . And this crash in london last saturday turned out not to be a terrorist attack, as was first feared. So was the news channel right to spend 1. 5 hours non stop reporting on it . First, recent news reports have featured allegations of sexual abuse in areas such as politics, sport, and broadcasting, and now, its hollywood that faces the unwelcome headlines in the person of harvey weinstein. The film producer, who denies the charges, has been accused of a number of assaults and of rape, and bbc news has covered the case extensively all week. With allegations of abuse against Sir Edward Heath and cyril smith also in the news this week. Neville dalton felt hazel murie wanted to know and graham stew begged on wednesday, bbc news ran a report about the introduction across the uk of universal credit a new benefits system which has been criticised for the impact it has on claimants. Social Affairs CorrespondentMichael Buchanan met one woman whos still waiting for payment eight months after first claiming. Whats been the worst part for you . Not being able to see my son. I cant sit and watch this for much longer. Its horrific. Its come to a point where my own child doesnt even know who i am. And all shes asking for is £54 a week. Derek hart was concerned that coverage of the implementation of universal credit gave what he called a biased picture