Video 1: Energy Geotechnics
So, let us talk about the energy which is the requirement for everybody in today’sworld, let me take you through a bit of the conceptual thinking first, I mean everybodyknows that energy is required and there are school of energy and energy sciences is veryfamous, in fact we have a school of energy also.Energy is the term which is multi-disciplinary, clear so a good name given to this is energygeotechnics.There is a journal also by Divya on energy geotechnique; international journal, so everybodyknows that there is a big demand for energy in the days to come, so everybody says saveenergy but you must be realise that in today’s society is clear, everything is energy based,so many mobiles, so many gadgets, laptops, so many tablets, so many electronic devicesto be charged every day morning.And we are talking about energy saving, what a paradox, check it out on the net that howmuch energy is required to sustain the society in another 20 years and what is going to helpyou in your sustenance, very soon you will realise 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 on where I am going to bring energy; people talk about hydro thermal;sorry, hydroelectric, people talk about solar, people talk about wind, people talk aboutyou know wave energy and so on, very insignificant quantity of the energy can be generated bythese devices at a very high expenditure.So, this also talks about you know, the fossil fuels are getting exhausted and their predictions,by what time the hydrocarbons will vanish, what time the coal will vanish, so the questionis what should we do beyond that, what are the consequences to the environment becauseof these fuels and this is there I hope you will realise that geotechnical engineers haveto 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 geotechnicalengineering, what we must be realising is that these are something very, very utopianbut yes, now people have started working and there are few guys who have gained lot ofknowledge and taken enough lead in these subjects now.Now, what happens is because of the complicated nature and extreme complex composition ofthe geomaterials.It becomes very difficult to understand you know what type of behaviour this materialswill exhibit, when you talk in terms of the energy geo technics, so all these conceptshave to be recast, they have to be re-understood, they have to be developed and masters is theright time when you know it is our job like people like us should train people like youto 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 betweenthe frozen state of the geo material which not many people study in undergraduate andeven post graduates unfortunately in our country but you will realise that these are the goldmines so, once you understand this subjects better, your you know, manoeuvrability becomesmuch more in your profession otherwise, you remain pertain to the old thoughts.So, energy geotechniques is the one which is the link between the frozen, ground andthe methane hydrate bearing sediments which are deciding a specifically.I do not know, how many you aware of carbon sequestration “Professor – student conversationstarts” To capture the carbon and yes, you are right, carbon captures, yes, you are right,I do not know the application, then you know everything, if you know that how to stealthe carbon from the environment.And pumped into the geo environment that is sequestration, alright, capturing somethingfrom somewhere and pushing it into another matrix.yes, want to say something in your words; like you capture and you sometimes store inthe sea, sequester.you call it blue carbon like other carbon, like this, okay, so for your help, I havea link, so it will talk about this sequestration process and where we are as a country, wellthis is a job mostly which was done by the guys who are in mining.“Professor – student conversation ends” So, they used to talk about methane gas sequestrationand geo technical engineers become very interested in this, why?Because there is a fluid phase and porous media is coal or porous media could be thesoils.So, if you see this paper; a coupled thermo hydro mechanical simulation for carbon-di-oxidesequestration, you can learn what is happening in this context, these are the guys who aredoing lot of work in this area.There is another one which is I think would be useful for you, this is another paper onfinite element model for simulation of carbon-di-oxide sequestration, alright, this was the volume1, issue number 3, I just to give you an idea about what is happening in the world in today'scontext, so the material in which the sequestration is taking place is the porous system, clear,it could be rocks, it could be soils, it could be coal, it could be resins, whatever.And then you are pumping in the gaseous phase or fluid phase, this is another interestingpaper; carbon sequestration potential of South Wales coal field, I think I was talking aboutthis.What is research gate?“Professor – student conversation starts” It is a platform for many research scholars,where they share ideas or they share queries, yeah, 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 researchscholars, very good, I am quite happy.“Professor – student conversation ends.”This is what the sequestration is in simple words, you know if you look at here, whatis happening is that most of the industries are emitting carbon-di-oxide in the environment,if I can capture it somehow and if I can pump into the deep aquifers, where you have methanegas, alright, so it is just like reverse of pumping out test which you did in hydraulics,you have this is pumping in test.But rather than water being injected, what I will do is; I will inject carbon-di-oxideso, carbon-di-oxide is heavier or methane is heavier, correct, so CO2 and CH4, so thatmeans lots of difference, alright, understood.So, you are flushing lighter gas by injecting heavier gas, clear, must have the whole heartand that is what the carbon-di-oxide sequestration is, read a bit more about it those of youare interested.So, here if you can see that they are inject wells sorry, they create wells and throughone of the wells, they will inject carbon-di-oxide and whatever methane is present in the aquifersparticularly, coal seams, they will flush it out from the other end, they can use itfor, so I am saved of mining because mining has 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 do deal with these type of situations in this course; environmentalgeomechanics.You know people are trying to talk about whether the nation should be depending upon the fossilfuel or they should go nuclear; I will come across something of this sort, whether treatiesare being signed by different countries, where you know government's fate might also dependupon the type of decisions which are taken in the country, check it on it, lot of informationis available.NPT; non-proliferation treaty, why we should go nuclear alright, and why they are not satisfiedwith the conventional processes, thermal; what is thermal; incinerate coal, run turbinesby steam which you do by boiling water and then run turbines and generate electricity,lot of consequences you produce enormous amount of fly ash.Big question is where to dump it, where to throw it, how to stop its movement into theatmosphere, air, volumes, so if you are incinerating let us say, certain amount of coal, equalamount of the fly ash gets generated or more than that, the calorific value of the coalis less, many a times, if the coal is of good quality, clear.Mining has own issues, several problems so, based on why do not we go for let us say somethingwhich is more sophisticated is the question which is the in the national debate.So, many are opposing this thing which party you will be belonging to, you want to opposenuclear power or you want to promote this nuclear power.“Professor – student conversation starts” You want to promote, okay, why?It has less disadvantage compared to thermal, okay what comes to your mind, what type ofless disadvantage it has?The wastage; as you said the fly ash; those problem will not be there in nuclear wasteThere 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 createa discussion on this, so many people have opposed you know that country should not gonuclear and we will talk about this.“Professor – student conversation ends.”Citing it is dangerous and difficult in disposing the radioactive waste, yeah that is true.So, here we talk about quantity versus not safety, intensity but nuclear power is saferthan most of energy sources and is needed if the world hopes to radically decrease itscarbon 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; this type of technology are supposed to be clean technologies, socheck it out on net what is mean by clean technologies however, suppose you know, thisis what the conventional thing is discussion, suppose if use uranium and suppose if I usecarbon, what is the risk associated with this, what are the volumes associated with thisyou know and this is where the energy geotechnics become very intense for people like us, whohave been dealing with both the sectors.I mean I deal with atomic sectors, l deal with the thermal power sectors and I understandwhat are the issues so, the question is if I use uranium and I use carbon, what is goingto happen?So, the situation is something like this, I mean the nuclear power uses uranium andcarbon is used by thermal power, this is how you can compare the 2, any guess what is what?Lack carbon and yes, it’s a ring in the finger, this is what has been is compared.So, the logic is you know, the volume of high-level vitrified waste which you generate for consumptionof nuclear power by a family of entire life is this, it is a reverse as what you are sayingand the volume of waste, if actinide which is present is also separated from the highlevel waste, so this is a comparison and the whole discussion was that when I incineratetons of coal, at what cost; by damaging the environment so much, by damaging the agriculturallands, clear.By creating so many other types of environmental issues, displacing people from one place toanother place because when you are doing mining, you have to acquire the land, you have todisplace the guys, alright.So, all these are the issues however, when you are adopting to the nuclear power now,this is what is going to happen, so the volumes are going to be extremely less but then whatis the other side of the story?Volumes are less but intensity of the waste in terms of concentration and radiation isextremely high.So, what a technology is does, he or she compares, x1 parameter, x2 parameter, x3, x4 parameterand let us optimise them, you understand, so this how the optimisation comes in thepicture.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 the geotechnical engineer you arerealising this from today’s discussion, is this part okay, how much you can contribute,you never imagine, how these atomic reactors will be run?“Professor – student conversation starts.”Sir, I was thinking like, it will be having more merits and at the same time, it is goingto 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 forth, correct, bigquestion, sir, even if we go for nuclear power plants, there will be issues related withthe mining of uranium and; the volumes are important, so from one mine, I can sustainwell for another 100 years of the lights, the amount of uranium which is present andcarbon; you must have heard about uranium enrichment also, know, in your 10th, +2 physicsyou must have done, I am sure.How do enrich the ores, it is a big technology.
Video 2: Contaminant-Geomaterial Interactions
So let us talk about now contaminant geomaterial interactions.Interaction part I think I have explained quite a lot and contaminants are also clearto you, anything which is unwanted, undesirable clear, which you never expected in the systemand what is our system; is geomaterials, alright or bi, sorry micro bio geosphere, if you rememberI sometime back I coined this term.So, in this system if any contaminant comes, it is not a good situation but suppose ifit 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 becausethe more and more furnaces I run, the more and more coal I was using tandoors for thatmatter you know, any type of oven, the more and more ash you are generating and you hadan 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 gettingplayed unfortunately, in this case you cannot do this because there are few watch dogs,who are watching what is happening in your country, this is being observed by internationalagencies.So, one of the options is that you would take this atomic waste contained it in canisters,canisters are normally made up of lead, you know because leads are retarders of atomicactivity; radioactivity.So, these canisters contain toxic waste which is nuclear in nature and normally, they arestored on the surface with special measures and they are covered, so this is the compactedgeomaterial and on this, I can grow the vegetation and there could be water level, good scenario,this is what is known as surface disposal, provided the activity of the toxic waste istolerable, so most of the waste which is coming out of the R&D units, our gloves, you knowthe scientist who are associated with the atomic waste; atomic activities.Surgeons, doctors who are giving therapies of different types by using different typesof isotopes, different type of medicines, weaponries, clear, irradiations of differenttype of crops; potato, onion, you must have notice, nowadays onions and potatoes do notgerminate, even if you keep them in your kitchen for several months why?During our days, a we were kids and you are of your age, you just buy it today and tomorrowit is used to germinate.What do they do, what magic they have done?Something interesting they have done, is it not, you agree, so there are facilities wherethe truckloads of the agricultural produce go and there irradiate it, 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 unitswere the activities 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 andhence 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 a stag like this on the ground, earth quake comes, there couldbe wear and tear of the canister itself and inside, the activities kept, so what is goingto happen; everything will become a part of the geoenvironment, it will spill over.So, whenever nuclear establishments have met with a disaster which was a recent one whichmankind is unable to forget?What happened there?Yes, a beautiful combination of the 2 thing which I have been discussing, clear, so itis a natural disaster influencing atomic establishment.Chennai, Kalpakkam, so read what happened there, you know is becoming a big issue, howto safeguard your establishments, you need millions of what; litres of water from thesea to run a reactor.So, you cannot put it in mainland, clear one advantage and disadvantage, second; now, disadvantageis Tsunamis, when they come, yes you are very right, what happened in Japan so?Clear, what happen in Chernobyl, clear, so these are the issues, in Kerala what is happening,what industries there at Chavira beach; so the bigger problem is not the titanium; titaniumcannot be mined like this, it is thorium.So, look at the beauty of the nature, why Kerala is so precious for the guys who areassociated with the atomic industry?The nature does magic, the sand which comes on the beach contains lot of activity in theraw form and this is processed in the Indian Rare Earth Limited, so they collect sand,it is blackish colour sand.Now, next time when you are there, please go and visit this site, alright and you saythat you are from IIT Bombay, you know the whole story and you like to see what is happeningthere.So, they do farming of sand, each time wave comes, it deposits, I do not want to losethis know, otherwise what will happen, it will go back, so they do literally scrapingof the top layer of the soil from the beach, they process it, they keep it aside, nextbatch comes but now, what is going to happen because of this?Yes, suppose, this process goes on, on and on and on, you are not returning anythingto the sea, what is going to happen?Beach erosion, that is what is happening, in most of the areas nearby, ride throughwall through the entire belt of Malabar belt and this tremendous problem with the countryis facing hope you are realising now the issues, each city has its own issues, ground waterand we will talk about why industrialisation could not be done, why atomic industry isflourishing and issues related to geoenvironmental aspects.So, the question here is that what type of geo materials should be utilised, so the questionmark here is that what type of geomaterials I should be using, from where they will come,so selection of geomaterial is a question mark, what properties this material shouldbe having?They should be protecting this unit against the rains, compacting them itself is a bigchallenge because the buried units are there inside and these buried units are quite active.So, you cannot just say I am compacting it, okay the properties which are required, nothingshould come out of it in any liquid phase, gaseous phase, okay, water table should notfluctuate so much that everything becomes wet, forget about the instability which youcan 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 shouldgo above the ground for disposal.Or I should go beneath the ground, clear, which one is better, no unique answer, I meanI will sometimes use this, I will sometimes choose this, I might make a trench over here,few tons of meters deep, I will design a good engineered back filled on the top of this,I will keep the toxic wet canister and burry it, make it perfectly sealed, so that evenif water table fluctuates, nothing should permeate into an out of it.Now, this is normally done for near surface disposal, there are lot of facilities in countrieswhich have been created known as NSDF; near surface disposal facilities, your most ofthe 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 ofmeter 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 themfrom the top because of the impact, they do not get crushed or burst and then use theback fill.Now, this is what is known as a deep geological disposal.A geotechnical engineers studies all these 3 situations, you know we are discussing bya leachate and I gave you an example about the landfill.The landfills are exposed to the environment, rains come the water interacts with the wastematrix and takes out the heavy metals; the same thing is going to happen here, if youare not careful.So, what I am showing with the red arrows is that the activity may leach out if youare not very careful, if the disposal system and the back fills and the compacted geomaterialsare not been designed properly.And when I say design, this is the material which has to be worthy of tolerating all theattributes of the waste, high-temperature, disintegration, radioactivity, chemical concentrationand so on, clear, it should not get altered for years together, so this is undesirablesituation.Now, the question is how would you check this?All these things are studied under the realm of post disposal, so this is the big word,you know post disposal or near surface disposal, people call it old disposal of atomic waste.And this is where geo technical engineers will play very, very important role, now Iam sure you will realise once this type of situation occurs, the geomaterial contaminatedtraction is going to takes place, the attributes of the waste which are going to come out fromthis unit are going to interact with the geomaterial which could be soil, which could be mineraland hence the interaction is going to take place.This opens up lot of revenue's for geotechnical engineers, you know and what are these revenues?First of all, site selection, what type of soil I should be using, where I should bedumping this waste, what type of geological formations which are worthy of locating ordepositing or throwing my waste, alright, we call this as worthiness of the candidaterepository, selection of the site becomes very, very important.If India has to become a nuclear measure, we should be having more and more disposalsites, clear and that depends upon the attributes of the waste which we are generating, selectionof geomaterial itself which are normally termed as barriers, covers, protective layers andso on, from where this type of soil will come, how would you place them, how would you makecovers out of it, so that nothing goes out of it, no radiations go out of it, water doesnot come into the system and so on.Post closure response; having done all these things you know, disposal, how the waste isgoing to interact with the geomaterial, it is a very big question and truly speaking,these processes are going to occur over several 10’s and 100’s of years, so when you aredesigning these type of systems, time becomes very important.Remember in the last lecture, I was talking about the environmental impact analysis hasto be done in 2 domains that is time domain and distance domain.So, x, y, z, t becomes my motive, so if at all this type of leakage take place, how thegeo environment is getting affected up to what distance, up to what time, another waywould be after this much time, how much would be the impact, so this is how most of theestablishments are designed, clear and then comes the monitoring.Once I have disposed of everything, how would I monitor whether the system is behaving alrightor not.So, if you understand all these steps, this is a very complicated thing but very, veryintricate but very you know evolving and it is basically, it catching the attraction ofseveral guys nowadays and this is where we talk about THMC; thermo hydro mechanical chemicalinteractions.I think I have already given you enough feedback about what is the thermal effect, the wastemight be at elevated temperature, how the hydraulics of the waste is going to come inthe picture at elevated temperature.How the mechanical property are going to change, compressibility, shear strength, consolidationand so on because of chemical interaction, the second one is THMC and B also I have addedto this, biological, so this is what is the coupling and interaction which is the orderof the day, everybody is trying to master this and I hope you can understand why thissubject will becoming more important because this has a strategic importance, this hascommercial importance and so on.
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