India Nuclear News And Discussion

somnath · Post by **somnath** » 25 Mar 2011 17:25

^^^Amit,

The question isnt about a "game" to gauging India's (or Pak's) actual bomb numbers...NPAs might have their dogmas, but to assume that they would would try and get India's numbers by forcing out some unintended confessions is stretching credulity...

FMCT, like CTBT, can "enter into force" only when all members sign up...Even if one member doesnt, entry into force cannot take place (which is preciely what happened with CTBT, when India refused to sign up, initially)...On FMCT, at least optically Pak is the only nation publicly holding out against it...From a US NP agenda perspective, if they can convince Pak to sign up on a deal, FMCT moves forward...Therefore, inspired estimates that projects a more muscular view of Pak's arsenal makes for a better diplomatic cover to pressurise Pak...

Most of these guys have been in the game too long to think that such estimates would cause any of the real principals to divulge things that they dont want to divulge, whichever side of the fence they sit on...

chaanakya · Post by **chaanakya** » 25 Mar 2011 17:43

somnath wrote:(which is preciely what happened with CTBT, when India refused to sign up, initially)

When did India sign CTBT?

ramana · Post by **ramana** » 25 Mar 2011 21:35

somnath wrote:Ramana-ji,

Thanks for the schematics..But question is - how does the PWR design cool the core once the coolant is drained? What "floods" the containment vessel?.....

I assume you ment PHWR. In a nuke reactor the only things that break from normal operations are the connecting pipes due to thermal fatigue. In particular the welds which have a stress concentration/dissimilar metals etc.

In the PHWR the vessel is below the pipes that connect to it. So if they break it still has its coolant and core doesn't get exposed.

In LWRs if there is pipe break the reactor vessel drains exposing the core and has a need for continuous coolant flow which could fail due to other reasons: failures: power, pump etc.

negi · Post by **negi** » 25 Mar 2011 23:36

I think all these schematics are 'CONCEPTUAL' in nature i.e. the physical design would vary from Generation to generation and even across Manufacturers. For instance what stops anyone from designing a PWR where the primary coolant pipes are above the fuel rods ? The reactor in Japan was a BWR it was not even a PWR so obviously in that case question of a ruptured coolant pipe flooding the reactor does not even arise (for the water is already in vapor state).

ramana · Post by **ramana** » 25 Mar 2011 23:42

Certification costs.

sivabala · Post by **sivabala** » 26 Mar 2011 00:03

somnath wrote:Ramana-ji,

Thanks for the schematics..But question is - how does the PWR design cool the core once the coolant is drained? What "floods" the containment vessel?\

Main reason for the stability of the PHWR in comparison to BLWR is the core has less active material in PHWR.

The reason for having less active material in PHWR is HW does not absorb neutron whereas LW absorbs neutrons leading to a decrease in neutron availability. To increase the neutron availability more active material is used in BLWR. Therefore, total neutrons required per kW of electricity generated is higher in BLWR. So the PHWR core, which requires comparatively less neutrons, operates at lesser temperature. Hence a core meltdown is relatively difficult to achieve in PHWR.

The objective of moderator is to slow down the thermal neutrons to activate the sterile U238 and sustain the chain reaction. In PHWR, in the absence of HW the neutrons simply escape. Hence the chain reaction cannot be sustained other than increasing the temperature by certain degrees. Whereas in BLWR, the active material has 5% U235, which will release more neutrons. Now in the event of lack of coolant to remove the waste heat, the chain reaction will melt the core and bring more active material closer that may accelerate the chain reaction.

JE Menon · Post by **JE Menon** » 26 Mar 2011 01:38

Pakistan is increasing its arsenal of nukes as quickly as it can not because of India (or not only because of India), but because it wants to increase the level of uncertainty among other powers which may be considering the prospects of intervention under one set of circumstances or another.

NRao · Post by **NRao** » 26 Mar 2011 02:31

JE Menon wrote:Pakistan is increasing its arsenal of nukes as quickly as it can not because of India (or not only because of India), but because it wants to increase the level of uncertainty among other powers which may be considering the prospects of intervention under one set of circumstances or another.

My sense too. Using India as a boogie it is fast becoming a NK. A card that Libya gave away. And, a card that China will use to bargain with others. Insane NK and TSP, orbiting China, will help China pull fast ones.

Amber G. · Post by **Amber G.** » 26 Mar 2011 05:04

X-post ( my rough guide to radiation numbers - putting it in perspective)
Let me summarize.. if you like you can keep it as a reference.

It is NOT the last word... The numbers in wiki or your favorite sources may and will differ.. and they may differ by a lot.

But these are the number(s) I will use, if I have to make a decision for my family, regarding radiation danger vs other danger in emergency situation. .. (Jump out of window/run or stay and take my chances)

Take it FWIW, and I humbly request folks here, not to take a pot-shot at me (OTOH if the potshots are at the numbers, thats welcome). There are, IMO no "right" numbers. All units are in mSV. Take these numbers as a guide and a rough guide only.

- Whole-body dose of 1000 mSV (or less) , you probably won’t notice.
(Body will repair most of the damage without ever making you sick)

- Larger doses are worse.

- 2000 mSV - (You’ll get sick, (or may even die). it is called "radiation poisoning" most of your hair
will fall out, nausea and listless. etc ... You may have seen this if you have seen some one undergoing radiation therapy. (usually to kill a cancer). You take this chance if risk justifies the benefit.

- 3000 mSV - Chances of death are about 50%, unless you get blood transfusion etc.
(Many references give 4500 mSV as Ld50 dose)

- 10,000 mSV will kill you within hours.. even medical treatment is unlikely to help.

Of course, amount of time, part of the body, your general health, age, and above all LUCK can and will change this.

Less than 1000mSV there are virtually no symptoms at all
Hope this is helpful..

BTW for gamma rays - To get 1 mSV of radiation, your body must be exposed to approximately 1,000,000,000 gamma rays. ( Just, in case you are listening to these Giger counter clicks)

Also for reference 1mSV = 100 mRem = 10,000 banana equivalent dose.

(Again - by no means the above means that doses less than 1000mSV is safe (or will not cause cancer).. it is just we can't say positively (in statistical way) that it will - we go on side of caution.. normal safe level, even for nuclear plant workers, are in the range of 50 mSV. )

somnath · Post by **somnath** » 26 Mar 2011 11:22

ramana wrote:In the PHWR the vessel is below the pipes that connect to it. So if they break it still has its coolant and core doesn't get exposed.

In LWRs if there is pipe break the reactor vessel drains exposing the core and has a need for continuous coolant flow which could fail due to other reasons: failures: power, pump etc.

Ramanai-ji, the presence of heavy water is one of the "design" safety features in a PHWR..But in case of a LOCA, in absence of any "intervention" the moderator that covers the core will soon heat up as well fairly soon...Which is why Indian PHWRs have an ECCS (emergency core cooling system) - which has various pumps and motors "externally" to kick in when a LOCA happens (refer to the article I posted above)...

Aa similar ECCS system is built into all LWRs as well - where the light water supply apparently is built "on top" of the reactor dome..In theory, a LOCA incident in an LWR should have the ECCS kicking in and flood the core with light water, pretty similar to what is designed in a PHWR...

Interesting studies of both PHWR and LWR ECCS operations here...
http://www.engineeringletters.com/issue ... 8_3_11.pdf
http://article.nuclear.or.kr/jknsfile/v38/JK0380697.pdf

somnath · Post by **somnath** » 26 Mar 2011 11:56

chaanakya wrote:
somnath wrote:(which is preciely what happened with CTBT, when India refused to sign up, initially)
When did India sign CTBT?

It hasnt..What I referred to was the 1997 CTBT conference, which broke up primarily because one country (India) publicly refused to sign up...

Sanatanan · Post by **Sanatanan** » 26 Mar 2011 14:29

ramana wrote: I assume you ment PHWR. In a nuke reactor the only things that break from normal operations are the connecting pipes due to thermal fatigue. In particular the welds which have a stress concentration/dissimilar metals etc.

In the PHWR the vessel is below the pipes that connect to it. So if they break it still has its coolant and core doesn't get exposed.

In LWRs if there is pipe break the reactor vessel drains exposing the core and has a need for continuous coolant flow which could fail due to other reasons: failures: power, pump etc.

Ramana Sir,

The schematics you had recently posted succinctly bringout the essentials of heat removal schemes in different reactor concepts. Thank you for the same.

I believe, we got into the present discussion in this thread about comparative LOCA scenarios between PHWR and EPR and BWR in the context of the Fukushima incident where there was a LOCA created due to absence of "shutdown cooling" (failure to remove the decay heat from the reactor core). I do not know whether there were any breakages/ruptures in the pipes that supply water (low pressure?) to cool the core(s) at Fukushima hours after the fission chain reactions in the reactor(s) had been stopped.

In this respect, may I request you to please give your views on the following two areas? I have not been very successful so far in finding answers to these points from the internet (I hope to keep trying, including reference to the two links posted by somnath-ji two posts ago which I had not seen earlier).

1) A basic comparison of the shutdown cooling requirements and methods adopted (in a general way, not necessarily delving into specifics) between a PHWR and an EPR and a BWR. In other words, in a situation when on-site as well as off-site electric and back up diesel power have been lost, how does one establish a path for transferring the decay heat from the core to the ultimate heat sink (sea water in the case of the coastal plant such as Fukushima, or, atmospheric air via the cooling tower in the case of an inland plant such as Narora)? Surely, the amount of "decay heat" in the core has a considerable influence on the Operator's ability to safely remove it? How long can an npp, particularly one having having higher decay power density in the core even in the shutdown condition, survive [meaning, not resulting in unacceptable / unmanageable release of radiation to the environment], without external energy input? Can plant designs [Nat U PHWR Vs Enriched U EPR/BWR] be compared on this "aspect of merit", if such a thing exists?

2) Specific to Fukushima, during the 1 hour between the reactor trip triggered by the earthquake instrumentation, and the arrival of the tsunami wave(s), did they not have a warning of the impending disaster? After elapse of 1 hour, immediately when the diesel-engine-driven pumps failed, could they have dumped the steam remaining in the (BWR) reactor vessel on to the turbine (which would have been separated from the electric grid by that time) and thus use the sea water circulating in the turbine condenser tubes as a means to remove the reactor core heat? This might have enabled depressurising the reactor earlier than they actually did and thus enabled earlier injection of low pressure water to remove the decay heat. Did more than one npp at Fukushima any share any common safety related system(s)? Were the npps at Fukushima operating with defective fuel elements in the core, thereby leaking fission products in to the coolant, even before the earth quake event?

I would be very thankful for your response.

abhishek_sharma · Post by **abhishek_sharma** » 27 Mar 2011 12:35

Can Nuclear Reactors Survive Blackouts?

http://news.sciencemag.org/scienceinsid ... ar-re.html

Readers ask: Are there any commercial nuclear plants that, when deprived of all electric power for a day, don't self-destruct and blow radiation?

Science answers: All of the most up-to-date designs of reactors, the so-called Generation III+, claim to be able to handle power outages, which are the main problem at Fukushima, some for up to 3 days. They do this by circulating cooling water via convection, rather than pumps, and top up the coolant with tanks positioned above the reactor, so gravity does the pumping work.

Some rely on pumps powered by steam from the reactor. All of them have multiple layers of automatic safety systems and their operators claim that they can theoretically walk away from them and the reactors will remain safe. All would require backup generators to keep control and instrumentation running, or at least batteries. It is impossible to make any such complex systems 100% safe from accidents, of course, but modern machines would cope with a Fukushima-style accident much more reliably.

Tamang · Post by **Tamang** » 27 Mar 2011 18:23

Fast breeder reactors are the least safe - SA Aiyar

The Indian nuclear establishment has long viewed FBRs as a great prize because these are indigenously engineered and can use India’s huge thorium reserves , eliminating dependence on uranium. Problem: conventional reactors are cooled by light or heavy water , but FBRs are cooled by liquid sodium, which is inherently dangerous. Liquid sodium reacts explosively with both air and water. Hence, even a tiny leak of sodium coolant can cause a fire. Fukushima shows that the unexpected can always happen despite precautions. When Fukushima overheated, the Japanese pumped in sea water and bombarded the reactors with water cannon to bring down temperatures. But such use of water would be impossible in any accident at an FBR—the water would react explosively with the sodium coolant. So, the real lesson of Fukushima is that FBRs are inherently risky. FBRs have long been touted as a patriotic feat of self-sufficiency . But they now need the closest scrutiny for safety by an independent agency. Scientists MV Ramanna and Ashwin Kumar say that Indian FBRs are dangerous for other reasons. First, the containment dome is not as strong as in other reactors. Second, they have a positive coolant void coefficient. Both these features bring down the very high costs of FBRs, which so far have proved to be financial disasters globally. But such costcutting comes at a price in safety.

GuruPrabhu · Post by **GuruPrabhu** » 27 Mar 2011 18:53

Tamang wrote: FBRs have long been touted as a patriotic feat of self-sufficiency . But they now need the closest scrutiny for safety by an independent agency. Scientists MV Ramanna and Ashwin Kumar say that Indian FBRs are dangerous for other reasons. First, the containment dome is not as strong as in other reactors. Second, they have a positive coolant void coefficient. Both these features bring down the very high costs of FBRs, which so far have proved to be financial disasters globally. But such costcutting comes at a price in safety.

I was wondering how long it would take the NPA brigade to use Japan accident to bash India. Looks like MVR won the race. Others will follow. Get your popcorn ready.

Does he know the plans for the FBR? If not, how can he critique it? Does he think that Indians are so silly that they will fight a sodium fire with water? Jai Ho!

But, the agenda becomes very clear here:

But they now need the closest scrutiny for safety by an independent agency.

Aah! Very clever. Use Japan to force IAEA inspections of FBRs. Kya kamaal hai!

GuruPrabhu · Post by **GuruPrabhu** » 27 Mar 2011 19:13

From the comments section:

What are you on? Fukushima happened because the tsunami knocked out the *outside* electric generators required to actively pump in cooling water. The weakness of this 40 year old design has already been fixed in 3rd gen designs, which are passive safety (electricity needed to operate, not cool) using gravity (i.e. pump-less) by keeping the coolant on top within the main body - whose integrity held. This is quite separate to the actual coolant like liquid sodium. The Japanese engineers who made these blunders are being laughed at by everyone unlike Indians who think "if Japanese messed it up we will". The other arguments and have to do with evolving technology elsewhere. You've been pretty irresponsible by trying to crowbar Fukushima into this debate in an effort to scare us off FBRs. The impressively named "International Panel on Fissile Materials" is a 5 years old body with a non-proliferation ideology and chaired by a JNU person and funded by a private American initiative. These are the same people who wouldn't have let us develop nuclear weapons if we had waited for their permission.

Sanatanan · Post by **Sanatanan** » 27 Mar 2011 20:25

Tamang wrote:Fast breeder reactors are the least safe - SA Aiyar

from the above article:

[quote]Risks at other reactor sites have been exaggerated. Jaitapur has some seismic risk, but far less than in reactor sites in Japan and Korea that withstood many earthquakes. Indian coastal reactors survived the 2004 tsunami, which hit the Tamil Nadu coast very hard. That lends some credibility to the government’s claims of safety on this count. The French-designed EPR reactor is said by critics to be not proven. Only one such reactor is still at the commissioning stage in Finland, after huge cost and time overruns. However, by definition every new technological advance is “unproven” and that can hardly be a reason for never going forward with new technology. Some critics of the “unproven” Jaitapur design say nothing about similarly unproven indigenous advances. Indian scientists have constantly innovated new and untested technologies and it would be silly to veto them all as unsafe. [/quote]

In the overall context of the entire anti-FBR article (citing known anti-Indian-nuclear commentatos), the above quoted paragraph singling out Jaitapur and the "French designed EPR", to sing its paeans, seems anomalous and also seems motivated.

Also, from the comments section of the article:

[quote]Dr K S Parthasarathy says:

March 27,2011 at 09:05 AM IST

Shri Swaminathan Iyer got carried away by the conclusions of M V Ramana and Ashwin Kumar.I recall that IGCAR scientists have convincing answers to those points. Mr Swaminathan should have verified whether his fears are true by discussing his doubts with the scientists in IGCAR. Fast reactors are not becoming popular now because many feel that it is uneconomic.Scientists in IGCAR contest this argument. Mr Iyer should not have judged FBRs and arrived at patently wrong conclusions without spending a few minutes with FBR designers or read appropriate technical literature. Admittedly these are highly complex matters; but he can seek guidance to arrive at his own conclusions. I respect Mr Iyer.I am writing this more in anguish than with anger realizing that such a respected economist got carried away so easily. I wish that the discerning public may distinguish corn from the chaff. Lack of carrying out home work can be damaging whether it is economics or nuclear technology. Dr.K S Parthasarathy[/quote]

PS: Have edited the post text to correctly place the [/quote] tag

joshvajohn · Post by **joshvajohn** » 28 Mar 2011 00:28

Kudankulam Nuclear Power Plant: A Threat To South India
http://www.countercurrents.org/vtp270311.htm

India NPP to be quake, tsunami-proof
http://english.ruvr.ru/2011/03/18/47598554.html

Voices Against Kudankulam Project
http://www.yentha.com/news/view/1/2759

'Kudankulam reactors are safe'
http://www.sify.com/news/kudankulam-rea ... adaih.html

Kudankulam reactor commissioning in April
http://www.thehindu.com/news/national/a ... 515150.ece

Closure of Kudankulam nuclear plant sought
http://expressbuzz.com/cities/thiruvana ... 59238.html

Rather than arguing against Nucler power, one may have to ask the questions such as how far it is safe in such eventualities of natural disasters. I see Kudankulam is just open to the sea. It is essential to build a reasonble green wall (with tall trees) or high cemeted walls upto 100 meters high so that such disasters can be prevented in the context of tsunami or flood or water raising from the sea. This could apply to Kalpakkam too. The Kalpakkan struggled with the previous Tsunami. Before people campaign against nuclear units it is esesntial that the government comes up with some plans for protecting these nuclear power centres and also people around them.

http://www.dinamalar.com/video_Inner.as ... 411&cat=32

GuruPrabhu · Post by **GuruPrabhu** » 28 Mar 2011 01:15

joshvajohn wrote: It is essential to build a reasonble green wall (with tall trees) or high cemeted walls upto 100 meters high so that such disasters can be prevented in the context of tsunami or flood or water raising from the sea.

Hi johvajohn,

Is this your suggestion or from one of the links that you posted? Assuming it is yours, let us build on it:

1. Thanks for calculating the height to be 100 m. Now, we need to calculate the thickness of this wall. An earthquake that generates a 100 m high tsunami must pack quite a punch. How do we ensure that the earthquake doesn't bring down the wall? How do we calculate the total force that this wall has to withstand to reflect a 100 m tall tsunami?

2. Trees are a wonderful idea. Please identify the species and let us figure out the growth rate for them to reach 100 m tall.

3. I would also like to propose 50 km tall chimneys for coal-fired plants so that the radioactive ash is sent to the outer atmosphere. Would you support this suggestion?

Vipul · Post by **Vipul** » 28 Mar 2011 01:32

BARC develops a Spent Fuel Chopper for PHWRs.

Bhabha Atomic Research Centre has developed a novel Spent Fuel Chopper (SFC) for the Pressurised Heavy Water Reactor (PHWR) fuel which will help in improving the utilisation/recycling of spent fuel.

"The indigenous development of the spent fuel chopper based on new gang chopping concept will significantly improve the capacity of head-end process of reprocessing," Scientists from Technology Development Division (TDD) and Nuclear Recycle Board said.

The first SFC, designed and manufactured as per the new concept, has undergone cold commission in Reprocessing plant in Tarapur and hot commissioning is in progress, Shaji Karunakaran and KNS Nair of BARC, and D A S Rao of the Nuclear Recycle Board said.

"It was seen that the shorter length of PHWR fuel (compared to Light water reactor or Boiling water reactor fuel) can be utilised to our advantage by adopting the concept of gang chopping," they said.

The new SFC has been designed to receive and handle a batch of 10 fuel bundles from a 220 MW PHWR, they said.

India has adopted a closed fuel cycle strategy and top priority is given to reprocessing of spent fuel as it enables recovery of materials that can be recycled.

India currently has 18 PHWRs and two reprocessing plants --one at Tarapur in Maharashtra and the other in Kalpakkam in Tamil Nadu.

negi · Post by **negi** » 28 Mar 2011 04:38

Guruprabhu, MVR has long been vocal against our FBR, you can google up a paper/article by him where he claims as to how unsafe our FBR design is (if I am not wrong I had posted it here a year back).

FYI

The safety inadequacies of India's fast breeder reactor

NRao · Post by **NRao** » 28 Mar 2011 06:17

Apologies if this has been posted earlier:

March 26, 2011 :: In expansion mode

S.K. Jain is confident that “we will be in a position to convince the people about the safety of Indian nuclear power plants”. “There is no cause for worry, be it about the indigenous nuclear power programme or the reactors to be imported,” he said. He said a Japan-type situation would not arise in India. He pointed out that the east coast was 1,300 km away from the Sunda Arc (tectonic plate boundary) and the west coast was 900 km away from the Makaran fault. When a powerful earthquake struck Bhuj in Gujarat on January 26, 2001, the reactors at Kakrapara in Surat district continued to operate safely. During the 2004 tsunami, the two reactors at Kalpakkam shut down safely and were brought back on line in four days.

The mean sea level (MSL) at Kalpakkam is 6.096 metres and the high tide level is 6.705 m. The tsunami water level in 2004 was 10.496 m. “The finished floor level of the nuclear island buildings of the PFBR site is 15.700 m, that is, they were 5.024 m clear of the tsunami water level in 2004. This means we have a high safety margin,” said Prabhat Kumar, Project Director, PFBR.

At Kudankulam, too, tsunami protection has been factored in. “We have a shore protection bund at an elevation of 7.5 metres above the MSL,” said M. Kasinath Balaji, Site Director, Kudankulam Nuclear Power Project. “The zero level (that is, the grade level) of all our buildings starts from 7.5 m above the MSL. We have a separate building called the safety building, which is flood-proof and has four diesel generator sets to provide alternative power supply [in case of a station blackout],” he said.

“The kind of decisions we have taken and the amount of money we have spent to safeguard our nuclear power plants is unparalleled,” said Baldev Raj, Director, Indira Gandhi Centre for Atomic Research, Kalpakkam, which is the home of India's FBR programme.

What happened at Fakushima Daiichi was that while the six reactor buildings there withstood the jolt of the earthquake, it was the unprecedented flooding by the tsunami that knocked out power supply from the grid to the units, inundated the backup DG sets and ruined the battery power sets. Besides, no mobile electricity-generating systems were available. The sea water mixed with the storage [light] water in the units. The plant personnel could not decide whether to use the sea water to cool the reactor core. Before mobile power-generation sets could be arranged, the fuel rods heated up because pumps could not pump coolant water to cool the fuel rods. Hydrogen started forming when the zirconium sheaths around the fuel assemblies reacted with air and it combined explosively with oxygen.

S.K. Jain said: “Yet, all the safety systems in those reactors worked. Even the shutdown systems, which are required to shut down the reactors in a few seconds, worked satisfactorily. All the safety systems worked as per design. The nuclear fission reactor in the units also stopped. So, as far as the design of the reactors at Fukushima Daiichi and their technology are concerned, there is nothing wrong.”

He said the strength of the Indian reactors lay in their passive heat removal system. The PFBR and the Generation 3I + VVER-1000 imported reactors at Kudankulam and the other reactors to be imported will have a passive heat removal system. In the case of Kudankulam, it is located at 43 m above the elevation level. It works on the principle of natural convection, without needing any electricity. There is an additional storage tank of water inside the containment building in case a LOCA [Loss of Coolant Accident] occurs. In the most unlikely event of a core-melt, the Kudankulam reactors have a feature called the core-melt catcher, which is a huge tank of water into which the fuel will fall in case of a severe accident.

Hydrogen accumulation will not take place in the reactor building at Kudankulam. Hydrogen recombiners are provided so that hydrogen and oxygen will combine to form water. This precludes the possibility of accumulation of an explosive quantity of hydrogen in the containment.

“I am convinced that there is no alternative to nuclear electricity in India both in the short term [about 10 to 15 years] and in the long term [40 to 50 years],” S.K. Jain said. He denied that the electricity to be generated from the imported reactors to be built in India would be expensive. “I will buy the reactors on my own terms,” he asserted. “The reactors should be technically acceptable to me and to our regulatory body, the Atomic Energy Regulatory Board. We will vet these reactors' designs to suit our requirements,” he said. “I cannot purchase expensive power. Otherwise, my company will become bankrupt.”

somnath · Post by **somnath** » 28 Mar 2011 06:32

Swami Aiyar should not be taken at any value for comments on nuclear affairs - his comments on the economy too are usually riddled with errors! This article of course seems to be a pure paraphrasing of MV Ramana's article...It would have been good to have the original piece in Science and Global Security - but its a "paid" affair..It would be useful o study the Indian PFBR design though in light of the claims made...Basically, two major claims are being made by MVR:

1. Defence-in-depth is weak - the containment building is "weaker" than comparable LWR/PHWR.
2. Positive void coefficient coolant..

One of the imperative points that come out from this debate (shorn of the noise on "trees", "857,000 killed" et al!) is the necessity for having an independent regultor...In spearate contexts, we have seen how the absence of a strong regulator wrecks havoc on the system - see telecom as an example...AERB should be made independent of the AEC..the manufacturer cannot be a regulator, as simple as that...

good news is that hot air is getting dispelled rapidly

..Especially all the rubbish about LWRs being "riskier" than PHWRs...

NRao · Post by **NRao** » 28 Mar 2011 06:41

I like the way these guys collect data points from all over the world then based on extrapolation predict Indian failures.

He should work it the other way around. Collect data points from India then extrapolate and pontificate to the rest to go Indian!!

somnath · Post by **somnath** » 28 Mar 2011 06:56

^^^NRao-ji, thats not fair entirely...A reactor design is a reactor design..For example, if th EPR design has certain design compromises, it would be so regardless of whether it is in finland or Jaitapur..the issue is when people start talking based on incomplete facts...

Amber G. · Post by **Amber G.** » 28 Mar 2011 07:19

Meanwhile in China:

Nuclear construction milestones at Haiyang 2

somnath · Post by **somnath** » 28 Mar 2011 11:30

Reaction of IGCAR to MV Ramana's original article in Science and Global Security, the one that Swami Aiyar took his inspiration from..

http://www.princeton.edu/sgs/publicatio ... editor.pdf

arun · Post by **arun** » 28 Mar 2011 20:14

Forbes on the Jaitapur Nuclear Power Plant that NPCIL is proposing to establish in Maharashtra:

A Perspective on the Nuclear Uproar in India

ramana · Post by **ramana** » 28 Mar 2011 23:28

Vipul wrote:BARC develops a Spent Fuel Chopper for PHWRs.

Bhabha Atomic Research Centre has developed a novel Spent Fuel Chopper (SFC) for the Pressurised Heavy Water Reactor (PHWR) fuel which will help in improving the utilisation/recycling of spent fuel.

"The indigenous development of the spent fuel chopper based on new gang chopping concept will significantly improve the capacity of head-end process of reprocessing," Scientists from Technology Development Division (TDD) and Nuclear Recycle Board said.

The first SFC, designed and manufactured as per the new concept, has undergone cold commission in Reprocessing plant in Tarapur and hot commissioning is in progress, Shaji Karunakaran and KNS Nair of BARC, and D A S Rao of the Nuclear Recycle Board said.

"It was seen that the shorter length of PHWR fuel (compared to Light water reactor or Boiling water reactor fuel) can be utilised to our advantage by adopting the concept of gang chopping," they said.

The new SFC has been designed to receive and handle a batch of 10 fuel bundles from a 220 MW PHWR, they said.

India has adopted a closed fuel cycle strategy and top priority is given to reprocessing of spent fuel as it enables recovery of materials that can be recycled.

India currently has 18 PHWRs and two reprocessing plants --one at Tarapur in Maharashtra and the other in Kalpakkam in Tamil Nadu.

GuruPrabhu, Is this pulverization based on ultrasonic technology like kidney stones are blasted with UT?

GuruPrabhu · Post by **GuruPrabhu** » 29 Mar 2011 01:02

It appears to be another shear system, except that it has increased capacity. Here is the BARC pub on it:

http://www.barc.ernet.in/publications/n ... 111209.pdf

abhishek_sharma · Post by **abhishek_sharma** » 29 Mar 2011 08:06

Current Designs Address Safety Problems in Fukushima Reactors

http://www.sciencemag.org/content/331/6024/1506.full

Despite the severity of the accident at the Fukushima I plant, nuclear reactor designers don't expect the same type of backlash against the nuclear industry as occurred a generation ago after Three Mile Island and Chernobyl. Their confidence rests on the fact that the reactors being built or planned today are quite different—and they say much safer—than those that are still smoldering in Japan.

Andrew Sherry, director of the Dalton Nuclear Institute at the University of Manchester, U.K., likens the differences to those between a car built during the 1960s and a car built today. Crumple zones, safety cages, three-point seat belts, and multiple airbags allow passengers today to walk away from a head-on crash almost unharmed, he says; not so in a 1960s car.

The Fukushima I reactors are very old reactor designs, direct copies of “the hairy edge of the first commercial plants in the U.S.” in the 1960s, says nuclear engineer Tony Roulstone of the University of Cambridge in the U.K. The new machines, using so-called Generation III+ designs, “have the benefit of 50 years of design evolution and operational practice,” Sherry says. Modern reactors have multiple layers of defense, use natural forces such as gravity and convection to move cooling water rather than rely on pumps, and employ automatic valves that kick in extra measures if necessary. Their manufacturers claim the reactors can be left for days and not overheat. “You can walk away from [such a reactor]. It's designed to cope with decay heat,” Sherry says.

The principles for designing a safe reactor haven't changed, however. “The essence of the safety case for any nuclear reactor,” says nuclear engineer Barry Marsden of the University of Manchester in the U.K., “is first to shut [the fission reaction] down and, second, to cool the fuel.” As at Three Mile Island, the three operating reactors at Fukushima (three were offline for refueling or repairs) executed the first of these tasks automatically following the earthquake. In boiling water reactors (BWRs) of the type used there, neutron-absorbing control rods are pushed upward from below the core to between the fuel rods, killing the fission chain reaction. This still requires power, however. In some modern reactors, the rods are held above the core with electromagnets so that a power outage will release them and gravity will do the rest.

But stopping the chain reaction doesn't neutralize heat production in the core. The radioactive decay of the fuel and fission products keeps generating as much as 7% of the full thermal capacity of the reactor, and cooling water must be actively pumped through the core to prevent overheating. “With a complete loss of power, decay heat did the rest” at Fukushima, Roulstone says.

The reactor designers of the 1960s considered a limited number of accident scenarios and devised systems to deal with each one. “Three Mile Island and Chernobyl changed the way people looked at safety,” Roulstone says. People realized that accidents can be complicated, have multiple causes, and that operators could do more harm than good. The lesson from those disasters: Expect the unexpected and prepare for the worst. “You have to accept there will be events that will overwhelm your systems,” says nuclear engineer Michael Golay of the Massachusetts Institute of Technology in Cambridge.

The design philosophy for reactors now is “defense in depth.” That approach requires duplicate systems and different technologies that can't, or shouldn't, all fail together. In the case of power supply, that might mean having more than one connection to the grid, an oversupply of diesel generators in different places, and batteries as a backup, along with possibly a flywheel system.

Loss of power, the main ongoing problem in Fukushima, is one of the most studied scenarios in the industry, Roulstone says, because in some designs, no power leads to an inability to keep the coolant moving and shifting heat out of the reactor. Consequently, all Generation III+ designs emphasize moving coolant with gravity and convection, driving pumps with steam, activating valves with DC battery power or no power at all, and keeping humans out of the loop.

One Gen III+ contender dispenses with pumps altogether to circulate the coolant. An updated BWR design known as the Economic Simplified BWR, for which GE-Hitachi is currently seeking regulatory approval, required extensive modeling to ensure that convection alone could move enough heat out of the reactor vessel. Other safety measures include automatic pressure-release valves, a large “suppression tank” to which steam can escape when pressure gets high, and water reservoirs above the reactor to top up the coolant—via gravity—if its level drops too low.

Hands-off cooling. GE-Hitachi's Economic Simplified BWR features depressurization valves (at the top of the pressure vessel), upper pools to top up the core cooling water by gravity, and lower pools to condense steam from the core.
CREDIT: COURTESY OF NEI

Westinghouse's AP1000 strives to make its systems as simple as possible by cutting down on piping, cables, and valves to reduce the possibility of problems. China is building the first four of this Gen III+ design, which uses convection to shift heat out of the reactor vessel into a massive tank of cooling water nearby. Decay heat is managed naturally without the need even for diesel generators. “It buys a grace period, giving operators some time to manage the situation,” Sherry says.

Golay hopes that Fukushima will spur designers to think harder about the problem of storing spent fuel. Modern reactor designs don't keep fuel in an elevated pool above the reactor like BWRs do but move it into a separate earthquake-proof building. No country has faced up to the spent-fuel problem and created centralized storage away from reactors or a long-term underground repository. “Maybe now attitudes will change,” he says.

Roulstone says the days may be numbered for old BWRs like those at Fukushima. But he thinks the imperatives of peak oil and climate change will keep nuclear in the mix of future energy sources: “I think people will face up to [the problems] and bite the bullet.”

Sanatanan · Post by **Sanatanan** » 29 Mar 2011 19:46

It is safe to go ahead with Jaitapur nuclear project

The DY Patil University (DYPU) of Kolhapur is associated with the Jaitapur Nuclear Power Project (JNPP). The department of atomic energy (DAE) and the Board of Research In Nuclear Sciences (BRNS) have awarded three projects to the varsity to carry out studies on baseline levels of radioactivity and assessment of radiation due to natural causes and fallout of radioactivity around JNPP up to a distance of 30 km from the site. The varsity’s vice chancellor and well-known physicist, Dr SH Pawar,explains to DNA why the Jaitapur project is safe notwithstanding the recent earthquake and tsunami in Japan that led to meltdown in some of the nuclear power reactors of that country.

. . .

Is there any latest research for controlling radiation leaks?
The US-based Radiation Shield Technologies (RST) has got the patent for Radiation Detectable and Protective Articles. This company has developed a protective material against all types of chemical, biological and radiological incidents. This material is a radiopaque nano-polymeric compound. The thin films can be prepared from such material which can block radiation. Scientists in India need to focus their research on creating such types of nanomaterial and technologies which can block radiation.

To me, this too seems to be some kind of "paid news". I believe gamma shielding requires high density materials such as lead, or even U-238. Will thin films of "nano-polymeric compound" be "radiopaque" ("radio-opaque"?) against gamma rays? Must do some more reading.

Amber G. · Post by **Amber G.** » 30 Mar 2011 04:22

You are right about lead for gamma shielding. Thin films, if I understand, what they are talking about, of "nano-polymeric compound, may be radio-opaque for, alpha-rays, cell phone radiation (

), or may be low energy medical x-ray, but not for higher energy photons ...( in practical sense at present any way..).

Amber G. · Post by **Amber G.** » 01 Apr 2011 01:30

Highly recommended for everyone who takes future of Bharat seriously.
Ignorance about Nuclear Power is Killing Us
And do check out Prof Cohen's page - Many things we discussed in these forum
http://www.phyast.pitt.edu/~blc/

You may like to check out Prof Cohen (in wiki) This is his Vita:
Vita

IMO, 90%+ scientific experts (eg, you go to a good university and ask who is their best prof) will agree with this view point.

Amber G. · Post by **Amber G.** » 01 Apr 2011 01:34

While googling for caffine and Plutonium, found this.

Promise you, this is worth reading for every person.
http://www.nucleartownhall.com/blog/tag/ralph-nader/

Amber G. · Post by **Amber G.** » 01 Apr 2011 03:16

(New) Poll - Re: Nuclear Power Support in USA
Wonder what the numbers are in India?

Sanatanan · Post by **Sanatanan** » 01 Apr 2011 06:55

Hindu, Front Page, )1 April, 2011
French Nuclear Safety Authority cannot rule out moratorium on Flamanville reactor

[quote]Paris: French Nuclear Safety Authority (ASN) president Andre-Claude Lacoste said on Wednesday that he “could not rule out” a moratorium on the third generation EPR nuclear reactor under construction at Flamanville in Normandy, northern France

“If the question of a moratorium is raised, and we have raised it, then it will be on the construction of Flamanville 3,” he said. The reactor has cost over € 5 billion to build and has run into delays and cost over-runs. Mr. Lacoste said the reactor, whose engineering works were led by the French electricity giant EDF, was “very compromised.”

This should be of interest to the Indian government since the Nuclear Power Corporation of India has entered into a framework agreement to purchase six identical reactors for the nuclear park in Jaitapur, Maharashtra, at a minimum estimated cost of €15 billion.

. . .

However, Areva appears to have developed cold feet following the ASN's declarations.

For, despite attempts to brush aside the ASN statements as “nothing extraordinary,” the company's shares were suspended from trading on the stock markets before bourses opened on Thursday.

. . .[/quote]

Sanatanan · Post by **Sanatanan** » 01 Apr 2011 07:42

Made-in-India reactors easier to regulate, says Jairam Ramesh

[quote]NEW DELHI: India's nuclear power growth must come from home-made heavy water reactors rather than foreign reactors using a variety of technologies in order to avoid Fukushima-style meltdowns, according to Environment Minister Jairam Ramesh.

In a letter to Prime Minister Manmohan Singh last week, Mr. Ramesh communicated the concerns of his Ministry regarding the safety of nuclear power as well as the public perception of that safety.

He argues that Indian regulators have expertise in Indian-made reactors and recommends that it is best to stick to what they know best.

. . .

. . .

Mr. Ramesh recommends that India must standardise its reactors, opting for the current 700 MW heavy water reactor and upgrading it to a 1,000 MW capacity as this is the type of reactor that Indian regulators have expertise in. With India's own uranium reserves doubling in the last five years, this would also be the most viable option. {1000 MWe in a standard/conventional PHWR may be difficult, unless some form of enrichment is used in the fuel. For me, sticking to Nat U is best. Big - here meaning, large MWe output capacity - is not always beautiful, nor the only most economical solution}. . .

Mr. Ramesh suggests that at multiple reactor sites such as Jaitapur — where six reactors will produce a total of 10,000 MW — each reactor must be given its own stand-alone support system rather than the current shared system. {I think that in India's standardised 220 MWe PHWR design as well as in 540 MWe PHWR, AERB codal requirements stipulate that no safety system shall be shared between two (or more) reactors at a site. I recollect reading some years ago that even in Tarapur 1 & 2 (BWRs), back-fitting was carried out, a few years ago, to make available redundant safety systems and ensure that each unit has is own dedicated redundant safety systems. In Pickering CANDUs, 4 reactors share a common "Vacuum building" an important safety system}

. . .
[/quote]
Edited to add "dedicated".

somnath · Post by **somnath** » 01 Apr 2011 07:59

Sanatana-ji,

Interesting developments...

Not sure how the economics of a "small sized PHWR" can be better than that of a large sized LWR...Any calculations?

The point on "expertise" is a bit rich though...By that logic, tomorrow if there is a breakthrough in nuke tech by Areva (the EPR is supposed to one such, but keep that aside), we will not implement it becuase of lack of familiarity? And are we planning to close down the Tarapur complex then, given that we should stick to PHWRs only?

Jairam Ramesh is a smart guy (I have personally had some interactions with him, long back

)...But somehow this whole "expertise" business seems to have been brought up as an afterthought by a few marquees of our commentariat - Brahma Chellaney in particular..Neither Srikumar Bannerjee, nor Kakodkar, nor indeed any of the known "rebels" (Santhanam, Gopalakrishnan) have articulated this point...And as a concept, sounds amazingly "unscientific", if I may..stretching that, we should never be trying out super-critical boiler tech, after al we have only done sub-critical boilers(under license production

) till now..

arnab · Post by **arnab** » 01 Apr 2011 08:23

I think in every country, the relevant regulators have started their CYA procedures