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PostPosted: Oct 10, 2009 8:00 pm 
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According to Nucleonics Week, India is going to build ten 700-MWe PHWRs (CANDU 6 size). They already have two 540 MWe PHWRs (Pickering sized), and they are presumably coming to the end of the construction of their 220 MWe size PHWRs (Douglas Point clones).
These reactors are not simply copies of AECL reactors - the Indians have put in significant development of their own (the 220 MWe units have improved containments, for example).

Quote:
Npcil now plans to build 10 700-MW PHWRs - four at
Kumharia, two at Bargi, and two each at existing plant sites,
Rajasthan and Kakrapar. Npcil on September 10 awarded a
contract to Mumbai-based equipment maker Larsen &
Toubro to design, manufacture and supply steam generators
for 700-MW PHWRs to be built as Rajasthan-7 and -8. In
March, the same company was awarded an order for steam
generators for Kakrapar-3 and -4


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PostPosted: Oct 10, 2009 8:52 pm 
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jaro wrote:
According to Nucleonics Week, India is going to build ten 700-MWe PHWRs (CANDU 6 size). They already have two 540 MWe PHWRs (Pickering sized), and they are presumably coming to the end of the construction of their 220 MWe size PHWRs (Douglas Point clones).
These reactors are not simply copies of AECL reactors - the Indians have put in significant development of their own (the 220 MWe units have improved containments, for example).

Quote:
Npcil now plans to build 10 700-MW PHWRs - four at
Kumharia, two at Bargi, and two each at existing plant sites,
Rajasthan and Kakrapar. Npcil on September 10 awarded a
contract to Mumbai-based equipment maker Larsen &
Toubro to design, manufacture and supply steam generators
for 700-MW PHWRs to be built as Rajasthan-7 and -8. In
March, the same company was awarded an order for steam
generators for Kakrapar-3 and -4




Jaro, I missed you. Welcome back. …Yes, I am a glutton for abuse.

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PostPosted: Oct 10, 2009 11:08 pm 
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From my limited understanding of AEC site, 700 MWe PHWR has the same number of tubes as 540 MW one. It just works hotter and 30% additional heat is transferred by partially boiling heavy water.
Logical (or illogical) conclusion:- Would it be possible to use supercritical steam or CO2 as coolant/heat transfer medium to transfer this amount of heat?


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PostPosted: Oct 11, 2009 12:09 am 
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jaro wrote:
.... they are presumably coming to the end of the construction of their 220 MWe size PHWRs (Douglas Point clones).


Maybe domestically, but this will be their primary export model. A proposal for reactor sales to Kazakhstan is already on the anvil, and Indonesia, Vietnam, the Philippines and Thailand have started informal talks with NPCIL.

Remind me again how much international interest there is in the ACR1000?


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PostPosted: Dec 29, 2009 2:59 am 
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About novel coolants, I always thought that the CANDU-OCR never got a fair shake. This was a CANDU that used a low-pressure organic coolant, and had the misfortune to be developed after the CANDU PWR was selected for production.

One was actually built and operated for 20 years, the WR-1. It gave good service. There were real advantages: The coolant was very predictable, the thermal efficiency was good (34%), the low pressure reduced sealing problems and ballooning. The coolant couldn't boil, so it prevented "dry out". I think there were also few or no corrosion problems, because nobody noticed or mentions them.

The one noticeable problem was that the coolant slowly degraded because of radiation.

Molten salts have many of the same advantages, and resist radiation better.

If these advantages could be combined with natural circulation, the result might improve safety as well as availability, compared to a pressurized water reactor.


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PostPosted: Dec 29, 2009 3:52 am 
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Talking of coolants, I have also thought a lot on the subject. I have also referred to the fluorocarbon Krytox in this context. Like the material referred to in WR-1, the stability of the fluorocarbons may also be limited to certain temperatures after which it could de-polymerize even though it is claimed to have better thermal and radiolytic stability in the product literature. However salt BeF2 is stable and highly soluble in water. A solution of this salt could substantially reduce the vapor pressures at various temperatures. The neutron absorption cross-section of the salt is likely to be less than that of the water. The solution could prove to be a better coolant for thermal reactors.


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PostPosted: Dec 29, 2009 2:23 pm 
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yes but the big negative in my mind is the coolant is flammable. I assume its much like a sodium cooled reactor if you keep the air out you would be okay.

http://www.unene.ca/un804-2006/Textbook ... %20add.pdf

The INL built a wax cooled reactor but never turned it on. Experimental Organic Cooled Reactor ....EOCR

Its legendary around the INL because the wax was excessed and some guy bought the tons of wax for a song and sold it to some shoe shine company for a good profit.


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PostPosted: Dec 29, 2009 10:31 pm 
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In the 1960s, William Lear was said to have an organic working fluid to be used instead of water for steam engines and steam cars; he called it learium. I seem to recall that it's life was limited because it gradually decomposed at the temperatures used.


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PostPosted: Feb 12, 2010 1:23 pm 
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The perfluorocarbon suggested by me is not flammable. It is a poorer moderator than heavy water but would reduce operating pressures in tubes. Other coolant I can think of is a concentrated solution of BeF2 in water. With a higher boiling point, it would also reduce operating pressure. I have also suggested a thorium fuel for PHWR but the concerned people feel handicapped by paucity of fissile feed.


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PostPosted: Feb 12, 2010 4:26 pm 
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jagdish wrote:
The perfluorocarbon suggested by me is not flammable. It is a poorer moderator than heavy water but would reduce operating pressures in tubes. Other coolant I can think of is a concentrated solution of BeF2 in water. With a higher boiling point, it would also reduce operating pressure. I have also suggested a thorium fuel for PHWR but the concerned people feel handicapped by paucity of fissile feed.


Quote:
the concerned people feel handicapped by paucity of fissile feed.


I have been very interested in your opinions as a window into the Indian value system that shapes the technical tradeoff evaluation process prevalent in your country and more broadly in the Asian countries in general.

It seems to me that a major factor in making decisions about civilian nuclear power is a general feeling of impoverishment in fissile feed availability. Clearly this situation has been exacerbated by long standing and dogged nuclear non-proliferation policies in play in the West.

When faced with such restrictions, it is a natural human response to “work around” the obstruction through other means and methods.

In the national interest of India, a promising workaround is to produce U233 through thorium based fusion/fission hybrid technology.

India is very rich in thorium and poor in uranium, so why the interest is fast uranium breeder technology especially in the light of the restrictive policies that have been propagated in the West especially by the United States. The US will strongly resist the spread of dual use uranium enrichment technology throughout the world into the foreseeable future.

Independent control of a countries energy production capacity is a prerequisite for national sovereignty.

And yet India and other Asian countries have wasted billions of valuable research and development rupees by joining the ill conceived fusion development partnership. The ITER project is clearly going nowhere slowly.

I will closely watch with interest how your opinions and predispositions evolve as a representative reflection of India’s seemingly illogical approach to nuclear development.

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PostPosted: Feb 13, 2010 3:08 am 
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jagdish wrote:
Talking of coolants, I have also thought a lot on the subject. I have also referred to the fluorocarbon Krytox in this context. Like the material referred to in WR-1, the stability of the fluorocarbons may also be limited to certain temperatures after which it could de-polymerize even though it is claimed to have better thermal and radiolytic stability in the product literature. However salt BeF2 is stable and highly soluble in water. A solution of this salt could substantially reduce the vapor pressures at various temperatures. The neutron absorption cross-section of the salt is likely to be less than that of the water. The solution could prove to be a better coolant for thermal reactors.


That Krytox idea is actually quite interesting. I've worked with that stuff for years in the lab and never quite got around to thinking about it as a coolant for reactors.

I would imagine, but do not know, that in a radiation field in the presence of water it would ultimately decompose into HF and various carbon oxides. As you say, it may depolymerize at some temperature as well.

I'm not sure I ever heated it to temperatures greater than 300C though, although truth be told, I have done some very sloppy things in the laboratory.


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PostPosted: Feb 13, 2010 3:08 am 
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jagdish wrote:
Talking of coolants, I have also thought a lot on the subject. I have also referred to the fluorocarbon Krytox in this context. Like the material referred to in WR-1, the stability of the fluorocarbons may also be limited to certain temperatures after which it could de-polymerize even though it is claimed to have better thermal and radiolytic stability in the product literature. However salt BeF2 is stable and highly soluble in water. A solution of this salt could substantially reduce the vapor pressures at various temperatures. The neutron absorption cross-section of the salt is likely to be less than that of the water. The solution could prove to be a better coolant for thermal reactors.


That Krytox idea is actually quite interesting. I've worked with that stuff for years in the lab and never quite got around to thinking about it as a coolant for reactors.

I would imagine, but do not know, that in a radiation field in the presence of water it would ultimately decompose into HF and various carbon oxides. As you say, it may depolymerize at some temperature as well.

I'm not sure I ever heated it to temperatures greater than 300C though, although truth be told, I have done some very sloppy things in the laboratory.


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PostPosted: Feb 13, 2010 6:43 am 
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Axil wrote
India is very rich in thorium and poor in uranium, so why the interest is fast uranium breeder technology especially in the light of the restrictive policies that have been propagated in the West especially by the United States. The US will strongly resist the spread of dual use uranium enrichment technology throughout the world into the foreseeable future.
The interest in fast breeders is really in the hope of "breeding" enough fissile feed for thorium while producing nuclear power. In a fast reactor, you can burn all the unspent uranium from thermal reactors and also the Transuranics. Even India has a lot of "spent" fuel with unspent U238. The aim to extract all the reactor grade plutonium and build up on stocks. Metallic fuel is the next step in development with higher neutron energy and conversion/breeding ratios. Even the higher cost of fast reactor power is a lower cost than Purchase of French reactors, for example. The main attraction is recovery of reactor grade plutonium on reprocessing. Once sufficient fissile matter is in stock, it contributes to energy security.
Current estimates are a pessimistic 30-40 years of fast reactors before thorium power can be put on a commercial scale. I have been nagging them on two points. One is to reduce risks of sodium fire. The other is simultaneous development of fast reactors (second stage of plan) and third stage (Thorium fuel). My personal agenda in participation in these discussions is to get more ideas on both these aspects so that I could convince them.


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PostPosted: Feb 15, 2010 4:18 pm 
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NNadir wrote:
jagdish wrote:
Talking of coolants, I have also thought a lot on the subject. I have also referred to the fluorocarbon Krytox in this context. Like the material referred to in WR-1, the stability of the fluorocarbons may also be limited to certain temperatures after which it could de-polymerize even though it is claimed to have better thermal and radiolytic stability in the product literature. However salt BeF2 is stable and highly soluble in water. A solution of this salt could substantially reduce the vapor pressures at various temperatures. The neutron absorption cross-section of the salt is likely to be less than that of the water. The solution could prove to be a better coolant for thermal reactors.


That Krytox idea is actually quite interesting. I've worked with that stuff for years in the lab and never quite got around to thinking about it as a coolant for reactors.

I would imagine, but do not know, that in a radiation field in the presence of water it would ultimately decompose into HF and various carbon oxides. As you say, it may depolymerize at some temperature as well.

I'm not sure I ever heated it to temperatures greater than 300C though, although truth be told, I have done some very sloppy things in the laboratory.


The Krytox is used for high temperature pumps lubrication as well. Contact with water has to be avoided, even if there is no reaction to the fluorocarbon, but evidently, this is the case for the LFTR as well, and generally, most types of outside contamination in the primary coolant of a nuclear power plant gets bad very quickly.


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PostPosted: Feb 16, 2010 6:53 am 
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Guys,

Same question I asked in another post! Are these PHWR/AHWRs competitive against the LWRs? Or, are these primarily to make U232 for the 3rd stage?

This has significance from the view that now India has access to high quality uranium ores from Namibia, Kazakhstan, etc. and the possibility of buying all the uranium it needs for commercial use. Under this scenario I don't see the point where India would invest in a technology which is not competitive in price.

PHWR are going to be under IAEA safeguards right? Anyways these can't be used for breeding fuel for warheads either!


- Nitin


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