 So, let us talk about the energy which is the requirement for everybody in today's world. Let me take you through a bit of the conceptual thinking first, I mean everybody knows that energy is required and there are school of energy and energy sciences is very famous, in fact we have a school of energy also you know, energy is a term which is multidisciplinary, clear. So, a good name given to this is energy geotechnics, there is a journal also by the way on energy geotechnics international journal. So, everybody knows that there is a big demand for energy in the days to come, alright, see everybody says save energy but you must be realizing that today society is clear, everything is energy based, so many mobiles, so many gadgets, laptops, so many tablets, so many electronic devices to be charged every day morning and we are talking about energy saving, what a paradox. Check it out on the net that how much energy is required to sustain the society in another 20 years and what is going to help you in your sustenance, very soon you will realize that mining of coal is a big curse, so and what do you produce out of it, we will discuss, alright. So, the question is from where I am going to bring energy, people talk about hydro therm sorry hydroelectric, people talk about solar, people talk about wind, people talk about you know wave energy and so on, very insignificant quantity of the energy can be generated by these devices at a very high expenditure, so this also talks about you know the fossil fuels are getting exhausted and their predictions that by what time the hydrocarbons will vanish, what time the coal will vanish, so the question is what should we do beyond that, what are the consequence to the environment because of these fuels and this is where I hope you will realize that geotechnical engineers have to play a very important role in the energy geotechnics, particularly nuclear energy, renewable resources, fossil fuels alright. So, this subject earlier you know never used to be discussed in the realm of geotechnical engineering, what you must be realizing is that these are something very very utopian, but yes now people have started working and there are few guys who have gained lot of knowledge and taken enough lead in these subjects now. Now what happens is because of the complicated nature and extreme complex composition of the geomaterials, it becomes very difficult to understand you know what type of behavior these materials will exhibit when you talk in terms of the energy geotechnics, so all these concepts have to be recast, they have to be re-understood, they have to be developed and masters is the right time when you know it is our job that people like us should train people like you to think ahead of what has already been done. Now this is a good example of now I am talking about the hydrates, what you are talking about from the very first lecture, you know what is the link between the frozen state of the geomaterial which not many people study in undergraduate and even post graduates unfortunately in our country, but you will realize that these are the gold mines, so once you understand these subjects better your you know manoeuvrability becomes much more in your profession, otherwise you remain curtailed to the old thoughts. So energy geotechnics is the one which is the link between the frozen ground and the methane hydrate bearing sediments which I will be citing specifically, I do not know how many of you are aware of carbon sequestration? Carbon sequestration meaning to capture the carbon and Yes you are right, carbon capture is yes you are right. I do not know the application then you know everything, if you know that how to steal the carbon from the environment and pump it into the geoenvironment that is sequestration alright, capturing something from somewhere and pushing it into another matrix, yes, want to say something in your words? Like you capture and you sometimes store in the sea, you call it blue carbon like other carbon like this. Okay, so for your help I have a link, so it will talk about the sequestration process and where we are as a country, well this is a job mostly which was done by the guys who were in the mining, so they used to talk about methane gas sequestration and geotechnical engineers became very interested in this, why? Because there is a fluid phase and porous media is cold or porous media could be the soils, so if you see this paper, a coupled thermo hydromechanical simulation for carbon dioxide sequestration you can learn what is happening in this context, these are the guys who are doing a lot of work in this area, there is another one which is I think would be useful for you, this is another paper on finite element model for simulation of carbon dioxide sequestration alright, this was the volume 1 issue number 3, just to give you an idea about what is happening in the world in today's context, so the material in which the sequestration is taking place is a porous system, it could be rocks, it could be soils, it could be coal, it could be resins or whatever and then you are pumping in the gaseous phase or fluid phase, this is another interesting paper, carbon sequestration potential of South Wales coal field, I think I was talking about this, what is research gate? It is a platform for many research scholars where they share ideas or they share queries in research gate. Correct, what is the advantage of this? You can like know the contemporary issues and you can solve the queries of other research scholars. Very good, I am quite happy, this is what the sequestration is in simple words, you know if you look at here what is happening is that most of the industries are emitting carbon dioxide in environment, if I can capture it somehow and if I can pump into the deep aquifers where you have methane gas alright, so it is just like reverse of pumping out test which you did in hydraulics, here this is a pumping in test but rather than water being injected what I will do is I will inject carbon dioxide, so carbon dioxide is heavier or methane is heavier, correct, so CO2 and CH4, so that makes lot of difference alright understood, so you are flushing lighter gas by injecting heavier gas, clear, master the whole art and that is what the carbon dioxide sequestration is, read a bit more about it, those of you are interested, so here if you can see that they inject wells, sorry they create wells and through one of the wells they will inject carbon dioxide and whatever methane is present in the aquifers particularly coal seams they will flush it out from the other end they can use it for, so I am saved of mining because mining has a lot of problems, so the whole mechanics of this process if you have to study this becomes very intricate, so I will try to touch upon how to deal with these type of situations in this course, environmental mechanics, you know people are trying to talk about whether the nation should be depending upon the fossil fuel or they should go nuclear, have you come across something of this sort where the treaties are being signed by different countries where you know governments fate might also depend upon the type of decisions which are being taken in the country, so check it on net, lot of information is available, NPT, non-proliferation treaty, why we should go nuclear, alright and why we are not satisfied with the conventional processes, thermal, what is thermal, incinerate coal, run turbines by steam which you do by boiling water and then run turbines and generate electricity, lot of consequences, you produce enormous amount of flash, big question is where to dump it, where to throw it, how to stop its movement into the atmosphere, air, volumes, so if you are incinerating let us say certain amount of coal equal amount of the fly ash generated or more than that, the calorific value of the coal is less many times if the coal is of good quality, clear, mining has own issues, several problems, so why do not we go for let us say something which is more sophisticated is the question which is the international debate, so many are opposing this thing, which party you will be belonging to, you want to oppose nuclear power or you want to promote this nuclear power, you want to promote, okay, why? It has less disadvantages compared to thermal, okay, what comes to your mind, what type of less disadvantages it has, the wastage as you said like fly ash, those problems will not be there in nuclear waste, there will be some other problems then, it is quite dangerous, it will yield more, yeah you are quite close to the correct answer, let me answer the question and let me create a discussion on this, so many people have opposed you know that country should not go nuclear and we will talk about this, citing its dangerous and difficulty in disposing the radioactive waste, yeah that is true, so here we talk about quantity versus, quantity versus not safety intensity, but nuclear power is safer than most of the energy sources and is needed if the world hopes to radically decrease its carbon emissions, so present day the biggest problem is carbon emissions, you produce cement carbon emissions, you produce steel carbon emissions, clear, you construct buildings carbon emissions, alright, so this is where these type of technologies are supposed to be clean technologies, so check it out on net what is meant by clean technologies, However suppose you know this is what the conventional thing is, discussion, suppose if I use uranium and suppose if I use carbon, what is the risk associated with this, what are the volumes associated with this, you know and this is where the energy geotechnics become very intense for people like us who have been dealing with both the sectors, I mean I deal with atomic sector, I deal with the thermal power sector and I understand what are the issues, so the question is if I use uranium and if I use carbon, what is going to happen, so the situation is something like this, I mean that nuclear power uses uranium and the carbon is used by thermal power, this is how you can compare the two and you guess what is what, carbon and yes, it is a ring in the finger, this is what is being compared, so the logic is you know the volume of high level vitrified waste which you generate for consumption of nuclear power by a family of entire life is this, it is reverse what you are saying and the volume of waste if actinite which is present is also separated from the high level waste, so this is a comparison and that whole discussion was that when I incinerate tons of coal at what cost, by damaging the environment so much, by damaging the agricultural lands clear, by creating so many other types of environmental issues, displacing people from one place to another place because when you are doing mining, you have to acquire the land, you have to displace the guys, alright, so all these are the issues, however when you are adopting to the nuclear power, you know this is what is going to happen, so the volumes are going to be extremely less but then what is the other side of the story, volumes are less but intensity of the waste in terms of concentration and radiation is extremely high, so what a technologist does, he or she compares, x1 parameter, x2 parameter, x3, x4 parameter and that is optimize them, you understand, so this is how the optimization comes in the picture, what I should be following, x1, x2, x3, x4 and what type of equation I am going to generate, how the economy of the country will get influenced, what is your role in the economy of the country, hope as a geotechnical engineer you are realizing this from today's discussion, is this part okay, how much you can contribute, you never imagine, how these atomic reactors will be run, so I was thinking like it will be having more merits and on the same merits but at the same time it is going to have like as you said the intensity will be more so related disadvantages also, so like how do we like fix that, this is the one that we have to go for, so correct, great question. Sir even if we go for nuclear power plants, are the issues related with the mining of uranium and all that. The volumes are important, the volumes are important, so from one mine I can sustain maybe for another 100 years of the life. The amount of uranium which is present in carbon. You must have heard about uranium enrichment also, no, in your 10 plus 2 physics you must have done, I am sure, how do you enrich the ores, it is a big technology, start quantifying things now, until now it was too much of abstract thinking, is it not, so let us talk about now contaminant geomaterial interactions. Interaction part I think I have explained quite a lot and contaminants are also clear to you, anything which is unwanted, undesirable, clear, which you never expected in the system and what is our system, is geomaterials alright or bio sorry, micro bio geosphere, if you remember I sometime back I coined this term, so in this system if any contaminant comes, it is not a good situation, but suppose if it comes I am helpless, I want to understand how the interactions are going to take place, so the first question which was asked is how would you dispose the nuclear waste, because the more and more furnaces I run, the more and more coal I was using, the lures for that matter, you know, any type of oven, the more and more ash you were generating and you had an idea, my ash I will dispose in your home, next door, is this correct, that is what happens, their ash comes to your courtyard, so we will throw it there, they will throw it here, this is how the game was being played, unfortunately in this case you cannot do this, because there are few wash dogs who are watching what is happening in your country, this is being observed by international agencies, so one of the options is that you take this atomic waste, contain it in canisters, canisters are normally made up of lead, you know, because lead are retarders of atomic activity, radioactive lead, so these canisters contain toxic waste which is nuclear in nature and normally they are stored on the surface with special measures and they are covered, so this is the compacted geomaterial and on this I can grow the vegetation and there could be water table, good scenario, this is what is known as surface disposal, provided the activity of the toxic waste is tolerable, so most of the waste which is coming out of the R&D units, our globes, you know, the scientists who are associated with atomic waste, atomic activities, surgeons, doctors who are giving therapies of different type by using different type of isotopes, different type of medicines, weaponrys, clear? Irradiations of different type of crops, potato, onion, you must have noticed, nowadays onions and potatoes do not germinate, even if you keep them in your kitchen for several months, why? During our days when you were kids and when you were of your age, you just buy today and tomorrow it used to germinate, so what do they do, what magic they have done, something interesting they have done, is it not, you agree? So there are facilities where the truck loads of the agricultural produce go and they are irradiated, read about this, very interesting way to create a profession for yourself. Another good example is, you know, so these are the applications of, you know, the units where the activity is being used for different purposes, is known as surface disposal, so all these type of waste which comes out of such units is within tolerable limits and hence, it can be contained and buried in a geomaterial. Then the question is what type of geomaterial I should be using and why? Suppose if I keep it stacked like this on the ground, earthquake comes, there could be the wear and tear of the canister itself and inside the activity is kept, so what is going to happen? Everything will become a part of the geo environment, it will spill over. So whenever nuclear establishments have met with a disaster, which was the recent one, which mankind is unable to forget, no question, what happened there? Yes, the beautiful combination of the two things which we have been discussing, clear? So it is a natural disaster, influencing atomic establishment. So read what happened there, you know, it is becoming a big issue, how to safeguard your establishments, you need millions of what liters of water from the sea to run a reactor, so you cannot put it in mainland, clear? One advantage disadvantage, second now disadvantage is tsunamis. When they come, yes, you are very right, what happened in Japan? Fukushima, clear? What happened in Chernobyl, clear? So these are the issues in Kerala, what is happening? What industry is there at Chawarabhich? So the biggest problem is not the titanium, titanium cannot be mined like this, it is thorium. So look at the beauty of the nature, why Kerala is so precious for the guys who are associated with the atomic industry? The nature does magic, the sand which comes on the beach contains lot of activity in the raw form and this is process in the Indian bare earth limited. So they collect sand, it is blackish colored sand. Now next time when you are there, please go and visit this site, all right? And you say that you are from IIT Bombay and you know the whole story and you like to see what is happening there. So they do forming of sand, each time wave comes, it deposits, I do not want to lose this, no? Otherwise what will happen? It will go back, so they do literally scraping of the top layer of the soil from the beach, they process it, they keep it aside, next batch comes. But now what is going to happen because of this? Yes, suppose if this process goes on, on and on and on, you are not returning anything to the sea, what is going to happen? Beach erosion, that is what is happening in most of the areas nearby. So I drove all through the entire belt of Malabar belt and this tremendous problem with the country is facing. Hope you are realizing now the issues. Each city has its own issues, groundwater and we will talk about why industrialization could not be done, why atomic industry is flourishing and issues related to geo-environmental aspects. So the question here is that what type of geomaterials should be utilized? So the question mark here is that what type of geomaterials I should be using, from where they will come? So selection of geomaterial itself is a question mark. What properties these materials should be having? They should be protecting this unit against the rains, compacting them itself is a big challenge because the buried units are there inside and these buried units are quite active. So you cannot just say I am compacting it. The properties which are required, nothing should come out of it, in any liquid phase, gaseous phase. Water table should not fluctuate so much that everything becomes wet. Forget about the instability which you can take care of. Vegetation should be done because plants ultimately provide a cover. Look at the second situation, yesterday I was asking this question whether I should go above the ground for disposal or I should go beneath the ground, clear? Which one is better? No unique answer. I mean, I will sometimes choose this, I will sometimes choose this. I might make a trench over here, few tens of meters deep. I will design a good engineered backfill on the top of this, I will keep the toxic wet canister and buried, make it perfectly sealed so that even if water table fluctuates, nothing should permeate into and out of it. Now this is normally done for near surface disposal. There are lot of facilities in country which have been created known as NSDF, near surface disposal facilities where most of the geotechnical engineers are working right now. They are giving solutions. The third one is deep disposal. You go quite deep inside the ground. This is hundreds of meter deep and where you encounter the rock mass and in this rock mass you keep the canisters and make sure that when you are dropping them from top because of the impact they do not get crushed or burst and then use the backfill. Now this is what is known as a deep geological disposal. A geotechnical engineer studies all these three situations. You know we were discussing about the leachate and I gave you an example about the landfill. The landfills are exposed to the environment, rains come, the water interacts with the waste matrix and takes out the heavy metals. The same thing is going to happen here if you are not careful. So what I am showing with the red arrows is that the activity may leach out if you are not very careful. If the disposal systems and the backfills and the compacted geomaterials have not been designed properly and when I say design this is the material which has to be worthy of tolerating all the attributes of the waste, high temperature, disintegration, radioactivity, chemical concentration and so on. It should not get altered for years together. So this is undesirable situation. Now the question is how would you check this? All these things are studied under the realm of post disposal. So this is a big word. You know post disposal or near surface disposal people call it or disposal of atomic waste and this is where geotechnical engineers play a very, very important role. Now I am sure you will realize once this type of situation occurs the geomaterial contaminant interaction is going to take place. The attributes of the waste which are going to come out from this unit are going to interact with the geomaterial which could be soil, which could be mineral and hence that interaction is going to take place. This opens up a lot of avenues for geotechnical engineers. And what are these avenues? First of all side selection, what type of soil I should be using, where I should be dumping these ways, what type of geological formations which are worthy of locating or depositing or throwing my waste. We call this as worthiness of the candidate repository. Selection of the site becomes very, very important. If India has to become a nuclear major, we should be having more and more disposal sites. And that depends upon the attributes of the waste which you are generating. Selection of geomaterial itself, which are normally termed as barriers, covers, protective layers and so on. From where this type of soil will come, how would you place them, how would you make covers out of it so that nothing goes out of it, no radiation go out of it, water does not come into the system and so on. Post closure response, having done all these things, you know disposal, how the waste is going to interact with the geomaterials is a very big question. And truly speaking these processes are going to occur over several tens and hundreds of years. So, when you are designing these type of systems, time becomes very important. Remember in the last lecture, I was talking about the environmental impact analysis has to be done in two domains that is time domain and distance domain. So, x, y, z, comma t becomes my motive. So, if at all these type of leakage take place, how the geo environment is getting affected up to what distance, up to what time, another way would be after this much time, how much would be the impact. So, this is how most of the establishments are designed, and then comes the monitoring. Once I have disposed of everything, how would I monitor, whether the system is behaving alright or not. So, if you understand all these steps, this is a very complicated thing, but very, very intricate, but very, you know, evolving and it is basically catching the attraction of several guys nowadays. And this is where we talk about THMC, thermo, hydro, mechanical, chemical interactions. I think I have already given you enough feedback about what is the thermal effect, the waste might be at elevated temperature, how hydraulics of the waste is going to come in the picture at elevated temperature, how the mechanical properties are going to change, compressibility, shear strength, consolidation and so on, because of chemical interaction. The second one is THMC and B also I have added to this biological. So, this is what is the coupling and interaction, which is the order of the day, everybody is trying to master this. And I hope you can understand why this subject is becoming more important, because this has strategic importance, this has commercial importance and so on.