India Nuclear News and Discussion 4 July 2011

[Cyrano]

A summary of recent orders

Vicky ji, is it prudent to collate and post such info even if the pieces are in public domain I wonder. N is one areas lot of forces have ganged up against us in the past, sabotaged, took lives of our scientists etc. Reposting press articles, official reports etc. is fine but do we need to go beyond ?

[Vicky]

A summary of recent orders

Vicky ji, is it prudent to collate and post such info even if the pieces are in public domain I wonder. N is one areas lot of forces have ganged up against us in the past, sabotaged, took lives of our scientists etc. Reposting press articles, official reports etc. is fine but do we need to go beyond ?

All of it is publicly documented tender PO award data from NPCIL's public website. Nothing secret or confidential here.

It's just collation of public data into a readable form since the incompetent media doesn't care or understand it.

Security through obscurity doesn't protect anyone in such issues. Most of the time govt just uses it as an excuse to escape scrutiny. Any determined enemy has more avenues to reach their objectives irrespective of security through obscurity.

Conflating transparency with security is counterproductive

[Vicky]

Hearing that the AHWR design is fully complete and BARC/NPCIL have applied to AERB for Construction consent for the first unit at Tarapur.


As per the 2017 plan this was supposed to be complete by December 2020 but this was delayed due to slow down in experiments due to covid.
One of the reasons that the design took so much time was because the fuel fabrication was too unsafe for operators even while hotcells were being utilised and forced BARC to chnage the fuel loading design to make the fuel fabrication safer.
This required the revalidation of all physics parameters.

The fuelling machine prototype, the coolant pumps have all completed five years of validation testing.

The designs for all components including reactor building, turbine building and associated buildings are complete.

C&I, Physics database have also been completed and signed off.

AERB is conducting the final Consenting design review.

NPCIL is awaiting PMO and FinMin clearance to start publishing tenders.

Real Construction start likely from Mid-2022. Commissioning by 2025-27. If they receive PMO and FinMin approval

[Anoop]

This news of AHWR is SO welcome!! I remember reading about Bhabha's vision for the 3 stage cycle in high school, more than 3 decades ago. Godspeed, BARC.

[Vicky]

This news of AHWR is SO welcome!! I remember reading about Bhabha's vision for the 3 stage cycle in high school, more than 3 decades ago. Godspeed, BARC.

This design could have started construction in 2012 itself but once the design went to AERB the regulator threw salt at the engineer's faces saying that they designed a stinker of an unsafe and unproven plant and were sent back to the drawing board saying that AERB won't sign off anything that hasn't been validated experimentally. Then BARC built many new experimental facilities like the AHWR Thermal Hydraulic Test Facility, AHWR Coolant pump test facility, Fuelling machine test facility, and also had to test more regimes in the AHWR Critical Facility.

Initial BARC's plan was to start construction of a half designed plant while they will design the rest of the plant. They didn't even design the production scale fuel fabrication and reprocessing equipment yet in 2011. Their plan was to validate only some regimes in the AHWR Critical Facility and validate the rest of the regimes in the production plant like the old school engineers used to do in the 1960s. Also the original design had a negative void coefficient in some regimes and not all, AERB asked them to go for a negative void coefficient in almost all regimes to future proof the design.

This rethink actually was necessary and prevented BARC from wasting time and money building a stinker. It also helped find serious design problems that could have backfired.

Most of these problems are now resolved, all regimes validated. Prototype fuel fabrication facilities established and validated.

Also AHWR will be useless to prove its design if PFBR doesn't start-up soon. The fuel for AHWR can only be available in sufficient quantities after PFBR operates for around 2 years, the PFBR spent fuel has to spend another year in a spent fuel pool cooling down and the highly fissile isotopes fission away so that the fuel becomes safe enough to reprocess. The cooled spent will take another 2 years to safely reprocess. 5 years from stable PFBR start-up is required to make one AHWR core. This problem was faced even during testing, FBTR wasn't able to supply enough fuel to power the AHWR Critical Facility to complete design validation experiments on schedule. FBTR was offline for a few years for upgrades too.

[Tanaji]

Thanks… what is the difference between PFBR and FBTR that you have mentioned? Both are fast breeder reactors used for producing Pu239. As per this:

http://www.igcar.gov.in/rfg/fbtrintro.html

The FBTR is a test bed, but then isn’t the PFBR as well given that it’s a prototype?

Another question is as per this
https://en.m.wikipedia.org/wiki/Prototy ... er_Reactor
The PFBR is used for Breeding of 233U for AHWR-300. I thought PFBR were generating 239PU for use in AHWR? Hence the name fast breeder as they generate more 239PU than what is used as fuel…

[Amber G.]

Among other things - FBTR uses mixed carbide fuel, PFBR will utilize a 30 percent plutonium oxide and 70 percent uranium oxide mixed fuel - (More details in any standard reference).

[Anoop]

Thank you, Vicky, for these details. One of my family members was called out of retirement from NPCL to assist with the commissioning of the PFBR, and told me that work was going on at a fast pace for the same. He is in the mechanical engineering stream, not nuclear physics. Now I can see why this is critical; didn't realize the delay in using the spent fuel from one to the other. Much obliged for the easy to understand explanation.

[Vicky]

Thanks… what is the difference between PFBR and FBTR that you have mentioned? Both are fast breeder reactors used for producing Pu239. As per this:

http://www.igcar.gov.in/rfg/fbtrintro.html

The FBTR is a test bed, but then isn’t the PFBR as well given that it’s a prototype?

Another question is as per this
https://en.m.wikipedia.org/wiki/Prototy ... er_Reactor
The PFBR is used for Breeding of 233U for AHWR-300. I thought PFBR were generating 239PU for use in AHWR? Hence the name fast breeder as they generate more 239PU than what is used as fuel…

FBTR is a research reactor built to validate breeder physics and figure out optimum fuel loadings etc. PFBR is a full scale operational plant but it is just called a Prototype because it's a first of a kind for India.

PFBR will manufacture U233 for AHWR and also breed Pu239 both for other FBRs and AHWR.

PFBR has two core rings and a blanket- the inner cores will make U233 from a mix of U235 and Pu. The outer blanket breeds Pu239 from Natural Uranium.

The AHWR also needs two types of fuel to work - Th232/U233 mix and a Th232/Pu239 mix. Both MOX variants are mixed to get the optimum Throium utilisation as Thorium is inherently non fissile while maintaining a safe negative void coefficient.

Fuel in PFBR - Pu239/U235/Natural Uranium mix in the inner cores. Natural Uranium/Depleted uranium blanket on the circumference.

Fuel in AHWR - Each fuel rod will have a mix of pins of Th232/U233 and Th232/Pu239

PFBR Core Layout -

Core 1 is 20.7% PuO2 in mix with spent UO2 made from spent PHWR fuel.

Core 2 is 27% PuO2 in mix with spent UO2 made from spent PHWR fuel.

The Blanket is Depleted Uranium (Mainly U238).

Core 1 and Core 2 areas make U233 from Pu239
The Blanket breeds more Pu239 from U238

For more info on PFBR: https://doi.org/10.1016%2Fj.nucengdes.2012.11.011

For more info on AHWR: https://www-pub.iaea.org/MTCD/publicati ... 0Kumar.pdf

2.2. 233U in self-sustaining configuration

One of the major objectives is to operate AHWR in the closed fuel cycle. The 233U burns and is bred in
situ in the cluster. It is possible only if system is self-sustaining in 233U. With irradiation, the 233U
content would deplete in the inner (Th,233U)MOX pins and would gradually build-up in the outer (Th,
Pu)MOX pins due to conversion from thorium. The production of 233U in the outer pins is however
not sufficient to compensate for the burn up of 233U in the inner pins. An alternate cluster is designed
for this purpose. The alternate cluster as shown in FIG.1 is basically same as the standard cluster
except that the 12 fuel pins in the alternate cluster contain 4.0 wt% plutonium in place of 3.0 wt%
233U used in the standard cluster [11]. Reactor is fuelled with both the clusters in equal proportion. It is
now possible to achieve the self-sustaining characteristics of 233U with the annual plutonium
consumption increasing by about 50 kg to 175 kg. The uranium from the discharged fuel would
contain other isotopes of uranium like 234U, 235U and 236U. But unlike the problem associated with the
recycling of MOX in PWRs, the situation here is simple as the rate of build-up of higher isotopes and
their absorption cross-section is much lower. The even higher isotopes do absorb neutrons but their
reactivity load is compensated by 235U. And it is possible to operate AHWR in successive cycles by
employing the same enrichment of 233U.

2.3. Plutonium as top up fuel

The usage and location of the plutonium in the cluster is important from the basic design objective of
minimising the plutonium requirement. This is done by locating the plutonium pins in the outermost
ring of the cluster, where it faces the highly thermalized flux. The plutonium used as top up fuel comes
from the spent fuel of PHWRs. It has about 75% fissile plutonium. By virtue of being placed in the
region of higher thermal flux, the plutonium leads to high fuel burn up. It however depletes at a faster
rate that result in strong burn up dependence of some safety parameters such as void reactivity
coefficient.

[Vicky]

Thank you, Vicky, for these details. One of my family members was called out of retirement from NPCL to assist with the commissioning of the PFBR, and told me that work was going on at a fast pace for the same. He is in the mechanical engineering stream, not nuclear physics. Now I can see why this is critical; didn't realize the delay in using the spent fuel from one to the other. Much obliged for the easy to understand explanation.

The reason for PFBR delays is a mystery though. If you ask them they either shut their mouth or beat around the bush quoting long resolved problems.

The initial issues in 2015 commissioning were high torque in LRP and SRP which required replacement of LRP and SRP. Then they said there were vibrations in the pumps, new pumps were designed and replaced by 2018.

Now they are saying they are replacing the gaurd pipe nitrogen circuit, but why? Is what they don't answer.

The problems they quote don't seem to need years to resolve making us question their credibility.

All I know is that the fuel was moved closer to the facility in 2020 to get ready for loading but now they are saying the replacement of guard pipe nitrogen circuit will take time and they are planning fuel loading in mid-2022

[Vicky]

NPCIL has again extended the tender deadline for GHAVP-1&2 Nuclear Island by 1 month. New DL is 30-Dec-2021 from the previous 18-Nov-2021. Further delays for unknown reasons. This is the last pending major tender for GHAVP-1&2.

This is the 5th deadline extension. Original deadline was 27-July-2021.

[Vicky]

A summary of recent updates:

GHAVP-1&2 IPHWR-700: Nuclear Island construction tender window closed on 31-Dec with no extension. Will likely hear about award in a month. As usual, L&T will likely win based on experience. BHEL and Tata Projects participated too.

68% Physical progress of the Construction of Phase -1 of Rehabilitation & Resettlement colony at Mahi Banswara Atomic Power Project : NPCIL as on 10 Dec 2021. Tentative completion date : June-2022

86% progress on construction of Rehabilitation dwelling units for Chutka MP Atomic Power Plant : NPCIL as on 10 Dec 2021. Tentative completion date : March-2022

[Vips]

India's nuclear arsenal recently went up the sophistication curve.

In the final months of 2021, India conducted two major missile tests. The first was the Shaurya hypersonic weapon test, which was conducted in October. The second was the Agni-P missile test conducted on Christmas Eve. Both missile tests indicate that India is on course to fielding a more sophisticated nuclear arsenal with greater diversity of delivery systems. These developments have triggered a flurry of analyses ranging from satisfaction over improvements in the Indian arsenal’s level of readiness to dangerous prognostications about what these missile developments might mean for strategic stability, especially between India and Pakistan.

Let us begin with what Shaurya and Agni-P imply for the state of readiness of India’s arsenal. These two missiles highlight the importance of expanding the repertoire of our nuclear-capable missile forces. India also tested a hypersonic weapon that is estimated to travel at a speed of Mach 5 and designed to dodge missile defences. Hypersonic weapons such as Shaurya are likely to be highly effective in taking out enemy early radars, static military installations such as airbases and command and control (C&C) facilities, although Shaurya may require a few additional tests to establish the credibility of its operational capabilities.

The Agni-P missile is believed to be capable of delivering multiple independent re-entry vehicles (MIRVs) or multiple warheads against a single target. This creates an opportunity for India to strengthen nuclear deterrence through ambiguity. Several analysts have inferred that Agni-P and Shaurya together represent a shift in India’s no-first-use policy. However, officially there is no evidence to suggest a change; India’s declaratory doctrine has remained steadfastly committed to no-first-use even as the country’s operational posture in the form of higher readiness levels undergoes a shift. The latter part is increasingly manifesting itself in the form of the ‘canisterization’ of India’s missiles, not only for longer range missiles such as intermediate range ballistic missiles (IRBMs), but also for the Agni-P, which is a short-range ballistic missile (SRBM).

Canistering missiles enables more rapid deployment, as warheads could already be mated with missiles and placed in climate-controlled tubes, preventing damage, for launch on short notice. Further, canisterized missile capabilities give India counter-force strike options, especially against Pakistan, according to some analysts who fear an intensification of strategic instability emerging from India’s missile progress.

Thus, because of India’s putative MIRV-based and canisterized ballistic missile forces, one school of thought holds that India could launch a pre-emptive strike against Pakistan’s nuclear facilities in the heat of a crisis. This view conveniently overlooks the fact that Pakistan has a larger nuclear arsenal than India’s and Rawalpindi’s refusal to adopt a no-first-use policy, despite past entreaties to do so. Pakistan also pursues an asymmetric escalation posture that involves the development and deployment of tactical nuclear weapons, but most critically early use of atomic weapons in a conflict with India, leaving us exposed to stand-off missile attacks. Moreover, it is misleading to argue that India’s canisterized and MIRV capabilities sow “strategic instability" when it is more the result of Pakistan’s pursuit of an offensive posture that involves the tactical use of nuclear weapons against a potential Indian conventional attack.

Indeed, the Pakistani presumption that the tactical and strategic use of atomic weapons can be kept separate is the primary source of instability. New Delhi has generally rejected the notion that decoupling the tactical and strategic use of atomic weapons is possible or sustainable because there can be no real distinction between counter-value and counter-force strikes involving such weapons, at least against Pakistan. Also, India’s pursuit of higher readiness levels in the form of Agni-P and Shaurya is only par for the course in that it is a justifiable insurance against a risk-prone adversary such as Pakistan. Although India has a stated no-first-use policy, combining it with a higher degree of operational readiness of its nuclear tipped-missile forces is also about pursuing nuclear deterrence, though through ambiguity, as it sows uncertainty and induces caution in India’s two nuclear adversaries, China and Pakistan. If anything, it complicates the first strike options of Beijing and Rawalpindi.

Beyond Pakistan, the advances in India’s missile capabilities are geared to deterring the People’s Republic of China. The latter has significantly superior capabilities than India. Beijing has deployed its Dong-Feng (DF)-26 IRBMs in the Xinjiang region of Western China. India’s Shaurya hypersonic weapon is equally a response China’s DF-17 Hypersonic Glide Vehicle (HGV) with a range of 1,800-2,500km, which Beijing is believed to have been fielding since at least 2019. Notwithstanding the caveat that New Delhi has generally rejected distinctions between counter-value and counter-force targets and tactical and strategic capabilities, Indian counter-force strike options are more plausible against China than Pakistan simply because a large number of the former’s land-based nuclear forces are more distant from population centres. Pakistan is acutely vulnerable to strategic interdiction due to its narrow geography as opposed to the geographic and strategic depth China enjoys. In any case, Beijing’s’s submarine-based nuclear capabilities give it a near invulnerable second-strike capacity, making India’s counter-force strikes against Chinese nuclear targets difficult. Thus, India’s hypersonic and canisterized Agni SRBM and IRBM capabilities are equally about preserving strategic deterrence and enhancing regional strategic stability.

[vera_k]

The reason for PFBR delays is a mystery though. If you ask them they either shut their mouth or beat around the bush quoting long resolved problems.

Is it plausible that the reactor is currently dedicated to military purposes? There's significant demand for weapons grade plutonium given recent testing.

[Varoon Shekhar]

^^
Nice article by Harsh Pant and co, but when did India test Shaurya in 2021? The last test was in Sept/2020. Unless it was a very discreet test that was announced later. Agni-1P was launched on Dec 18th. Technicalities, but..

[Amber G.]

Just for fun: A historic photograph with giants - Can you identify who, when where?

Maha hint: Rightfully called for starting the whole nuclear thingie - and dream for the ambitious three stage nuclear program.

(We do have PHWR, FBR -- Thorium Based Reactors (Not yet in true sense) from that work)

[Y I Patel]

Homi Bhabhi, JRD Tata, maybe Vikram Sarabhai? Don’t know the gent JRD is shaking hands with

[Suraj]

I'm guessing the person on the left is Neils Bohr - mainly from the jaw shape.

The one on the right looks like Zhou Enlai from the eyebrows, but clearly it can't be him.

[Amber G.]

Great work!
Yes, the person JRD shaking hands with is Niels Bohr. Here are some other pictures of him for perspective around the same time:

or (Can you identify the scientist who is carrying a person in the arms .. here?)

and a little earlier - quite famous:


---
The original picture, I posted in previous post is around 1960 - Taken in TIFR.
The people are: L-R Niels Bohr, Homi Bhabha, JRD Tata, and Homi Bhabha's brother Jamshed Bhabha. Jamshed Bhabha - probably not as famous as his brother was an accomplished artist - With paintings, architecture and theater connected connected with TIFR and other institutes.

Check out -
Nuclear Science to Performing Arts: How the Legendary Bhabha Brothers Shaped India

Niels Bohr - No other scientist in the history of physics has even come close to number of Nobels or great scientists this giant cultivated. He was one of Bhabha's guru - but virtually every great physicist (from Heisenberg to Pauli to Bose and most Indian Scientists of that era) spent time at his institute or learnt nuclear physics from him.

He was a great asset to India - in teaching the scientists and making trips to India to help... Father of modern nuclear physics in true sense...

TIFR - still remains to be a premier institute in India.

[Amber G.]

Okay - two more pictures from archive -

1) Who? When? Where?
(Without these giants - India's nuclear program (and science/technical/space program) would not have taken place.


2) Who? When? Where? How?
Another historic picture - IMO this resulted into one of most beneficial meeting ( How?)


(Who is probably easy to answer , but when, where and how are interesting for India's science/technical/space program)

[Hiten]

updates about Nuclear Battery development by BARC

https://www.spansen.com/2022/03/barc-ma ... ssion.html

[Vips]

BHEL dispatches nuclear steam generator to NPCIL for Rajasthan project.

State-owned BHEL has dispatched its 42nd nuclear steam generator to NPCIL for installation at a 700 MWe unit in Rajasthan Atomic Power Project. The steam generator was flagged off from BHEL's Trichy plant in the presence of senior officials of BHEL and NPCIL.

"Bharat Heavy Electricals Ltd (BHEL) has achieved a major milestone with the despatch of its 42nd nuclear steam generator to Nuclear Power Corporation of India Ltd (NPCIL)," a company statement said.

BHEL has been catering to the nation's nuclear programme since 1976 by way of design, manufacture, testing and supply of critical nuclear components like reactor headers, steam generators, steam turbine generators, among others.

The first stage of the indigenous nuclear power programme of the country has attained maturity with 18 operating Pressurised Heavy Water Reactors (PHWRs).

As many as 12 PHWRs accounting for 74 per cent of the indigenous nuclear power capacity are equipped with BHEL supplied steam turbine generator sets.

[Vips]

Beginning 2023, India to start building nuclear power plants in fleet mode.

With the first pour of concrete for a 700 MW atomic power plant in Karnataka's Kaiga scheduled in 2023, India is set to put in motion construction activities for 10 'fleet mode' nuclear reactors over the next three years.

The first pour of concrete (FPC) signals the beginning of construction of nuclear power reactors from the pre-project stage which includes excavation activities at the project site.

“The FPC of Kaiga units 5&6 is expected in 2023; FPC of Gorakhpur Haryana Anu Vidyut Praiyonjan units 3 & 4 and Mahi Banswara Rajasthan Atomic Power Projects units 1 to 4 is expected in 2024; and that of Chutka Madhya Pradesh Atomic Power Project units 1 & 2 in 2025,” officials of the Department of Atomic Energy (DAE) told the Parliamentary panel on science and technology.

The Centre had approved construction of 10 indigenously developed pressurised heavy water reactors (PHWR) of 700 MW each in June 2017. The ten PHWRs will be built at a cost of Rs 1.05 lakh crore.

It was for the first time that the government had approved building 10 nuclear power reactors in one go with an aim to reduce costs and speed up construction time.

Bulk procurement was underway for the fleet mode projects with purchase orders placed for forgings for steam generators, SS 304L lattice tubes and plates for end shields, pressuriser forgings, bleed condensers forgings, incoloy-800 tubes for 40 steam generators, reactor headers, DAE officials said.

Engineering, procurement and construction package for turbine island has been awarded for Gorakhpur units three and four and Kaiga units five and six, they added.

Under the fleet mode, a nuclear power plant is expected to be built over a period of five years from the first pour of concrete.

Currently, India operates 22 reactors with a total capacity of 6780 MW in operation. One 700 MW reactor at Kakrapar in Gujarat was connected to the grid on January 10 last year, but it is yet to start commercial operations.

The PHWRs, which use natural uranium as fuel and heavy water as moderator, have emerged as the mainstay of India's nuclear power programme.

India's first pair of PHWRs of 220 MW each were set up at Rawatbhata in Rajasthan in the 1960s with Canadian support. The second reactor had to be built with significant domestic components as Canada withdrew support following India's peaceful nuclear tests in 1974. As many as 14 PHWRS of 220 MW each with standardised design and improved safety measures were built by India over the years.

Indian engineers further improvised the design to increase the power generation capacity to 540 MWe, and two such reactors were made operational at Tarapur in Maharashtra. Further optimisations were carried out to upgrade the capacity to 700 MWe.

[kit]

How difficult is it to scale up the design from 700 to say 1400 MW reactor ., would this need a new design altogether ? wont there be more economies in building bigger reactors ?

[Cyrano]

The new trend is to build a battery of smaller modular reactors these days as evinced by the future plans of France and others.

[Vips]

How difficult is it to scale up the design from 700 to say 1400 MW reactor ., would this need a new design altogether ? wont there be more economies in building bigger reactors ?

IIRC, the next scaling up planned/being done is to 980 MW.

[Sanatanan]

How difficult is it to scale up the design from 700 to say 1400 MW reactor ., would this need a new design altogether ? wont there be more economies in building bigger reactors ?

Since the question refers to 700 MWe, I presume it is about India-developed- designed-and-built 700 MWe PHWRs. This is a fairly verbose response, hope the reader won't mind.

PHWR reactors use Natural-U as fuel and Heavy water (D2O) as Moderator and as Coolant. There are approximately 400 Numbers of tubular 'Channels' (called Coolant Channels) containing 12 Numbers of 1 Metre long Natural-U fuel bundles. Between 2 Coolant Channels there is D2O Moderator. Optimisation of the centre distance between the Coolant Channels, called ‘Coolant Channel Pitch’ is mainly determined by Reactor Physics considerations and plays an important part in maintaining Neutron economy, a vital requirement for Natural-U reactors, especially for our country. So, if 700MWe is to be upgraded to 1400 MWe, then a greater number of Channels (at approximately the same pitch) would need to be incorporated in the design. However, there are practical engineering and manufacturing limitations of incorporating in the design, a correspondingly larger Reactor Vessel (called Calandria), apart from other engineering considerations of associated Civil Structures and plant design of other systems. I believe, even Canadians have not gone beyond 900 MWe CANDU-s. So, in my view, upgrading 700 MWe design to 1400 MWe NPP is not likely to be feasible as of now. Nor do I think such upgrading will necessarily be useful. It may be better to construct multiple numbers of standardised 700 MWe Units (in Fleet Mode, as proposed now) at the same site, rather than build larger Units. “quantity-based” cost advantage is likely to accrue in place of "size-based" cost advantage. Also, with bigger Units. cost of even a temporary shutdown (say for mandatory periodic Regulatory Inspection) from the Grid is likely to be higher, compared to multiple smaller sized Units, all of which are less likely to get into a shut down mode simultaneously.

An alternative to increasing the number of Channels in a PHWR concept discussed in the paragraph above, could be to increase the enrichment of the Fuel Bundles. While this may or may not let us go up to as much as 1400 MWe power output level with lesser increase in the number of Coolant Chanels needed, some increase in power output above 700 MWe might be possible. But design of enriched Uranium PHWR may be a different “kettle of fish”, what with different safety considerations and other Reactor Physics & engineering issues. I would not go this way. I shall continue to be a vegetarian, not eating "fish"

A third alternative may be to jettison PHWR concept altogether and go in for LWR design, which would again require fairly high level of enrichment. (But this would not fall under the "upgrade existing design" category !) Again, I would not opt this approach, although world over, those who can afford to waste Neutrons (at the expense of Neutron economy that a PHWR offers), have adopted this concept. We need all the Neutrons we can garner, for converting Th-232 to U-233, which is like to subsequently become the life line to meet our energy requirements for base-load power generation.

In other words, in my view, briefly put, use of enriched uranium in thermal neutron spectrum reactors such as PHWRs, LWRs and SMRs etc are not suited for our country for land-based nuclear power generation. (Ok for submarine nuclear propulsion reactors which are likely to be smaller in number as well as much smaller in power output size.)

Iamge 1 : PHWR schematic

[ http://www.nucleartourist.com/images/candu-7a.jpg ]


Image 2 : Schematic of Calandria Vessel Assembly of India's PHWR

[ https://d3i71xaburhd42.cloudfront.net/7 ... ure1-1.png ]

Image 3: Calandria Vessel of a CANDU (PHWR) Reactor

[ http://www.nucleartourist.com/images/candu14a.jpg ]

[SSridhar]

Thank you Sanatanan. Very well explained.

[kit]

How difficult is it to scale up the design from 700 to say 1400 MW reactor ., would this need a new design altogether ? wont there be more economies in building bigger reactors ?

Since the question refers to 700 MWe, I presume it is about India-developed- designed-and-built 700 MWe PHWRs. This is a fairly verbose response, hope the reader won't mind.

Good explanation ! .. thanks very much ., i was wondering since every major country has gone for higher capacity reactors in the past so why stick with 700 mw !! .. so is there a sweet spot for PHWR for capacity upgrade in the Indian context ? also how does this fit into the Thorium cycle .. we are yet to see full scale implementation of the FBR

[vera_k]

Primordial helium

This article mentions helium can be produced as a result of tritium decay. Wonder if this is something that's commercially viable with the quantities of tritium extracted from the PHWRs.

[Amber G.]

^^^ FWIW - There are two kinds (isotopes) of helium. Most abundant is He4 (Two proton+ Two neutrons) which mostly comes from radioactive decay from Uranium/Thorium stored inside earth's crust (and extracted from underground wells/caves etc) This is the kind which is used in balloons etc..

He3 (Two protons + a single neutron) is the one which is (generally) produced by tritium extract. He3 (which is 25% lighter than ordinary and also has lower melting point) has many uses in science and technology.

(Basically, from a physics point of view -- the quantum mechanical effects on helium-3 and helium-4 are significantly different because with two protons, two neutrons, and two electrons, helium-4 has an overall spin of zero, making it a boson, but with one fewer neutron, helium-3 has an overall spin of one half, making it a fermion.

Helium-3 is also a non-radioactive isotope but offers remarkable advantages -- its fusion with deuterium is more efficient than deuterium-tritium and does not release neutrons but protons, which can be easily contained thanks to their positive charge

He3 has lot of other applications - eg in low temperature physics - and thus have some commercial applications in many places)

Hope this helps.

[Amber G.]

^^^ Interestingly, with Chandrayaan India has lot of interest in Hel-3. He-3 is extremely rare on Earth but it is 100 million times more abundant on the Moon. Mining of He3 could be practical in not too distance in future. There are many non-energy applications of He-3. One such application for India is security aspect monitoring possible terorristan originated dirty bombs. (its ability to detect neutrons coming from Pu from dirty bombs etc)

[Amber G.]

Centre gives in-principle nod to 5 sites for N-plants; efforts

[Sanatanan]

India announces 3rd negative arms import list,
Rajnath cites Huawei & warns against security
breaches
http://timesofindia.indiatimes.com/arti ... aign=cppst

In above article there is a reference to "anti-radiation missiles". Curious to learn what might it be. Would be grateful for Gyan regarding this. Thanks
Sanatanan
08/04/2022
=========

[Tanaji]

The radiation being referred to is electro magnetic radiation as opposed to alpha, beta and gamma particle radiation. The former is what a radar, a phone etc emits , the latter is what we term radioactive elements such as uranium, plutonium emit.

An anti radiation missile is thus one that detects large electro magnetic radiators such as radars and targets itself on that.

[Sanatanan]

The radiation being referred to is electro magnetic radiation as opposed to alpha, beta and gamma particle radiation. The former is what a radar, a phone etc emits , the latter is what we term radioactive elements such as uranium, plutonium emit.

An anti radiation missile is thus one that detects large electro magnetic radiators such as radars and targets itself on that.

Thank you very much for the clarification.

Sanatanan

[Haridas]

Also AHWR will be useless to prove its design if PFBR doesn't start-up soon. The fuel for AHWR can only be available in sufficient quantities after PFBR operates for around 2 years, the PFBR spent fuel has to spend another year in a spent fuel pool cooling down and the highly fissile isotopes fission away so that the fuel becomes safe enough to reprocess. The cooled spent will take another 2 years to safely reprocess. 5 years from stable PFBR start-up is required to make one AHWR core. This problem was faced even during testing, FBTR wasn't able to supply enough fuel to power the AHWR Critical Facility to complete design validation experiments on schedule. FBTR was offline for a few years for upgrades too.

All these years India has stockpile of U233 from Thorium in the outer ring of PHWR.
So AHWR fuel cycle has slack builtin.

Secondly India can import medium enriched fuel to cover for neutron deficit. The neutron corossection of U233 is similar to U235.

[Hiten]

.
NPCIL Halts Commissioning Of IPHWR-700 At Kakrapar & Other Indian Nuclear Updates

Power generation has stopped at the first IPHWR-700 Reactor, Unit #3 of KAPS since no later than November 2021. NPCIL has also halted it's further commissioning activities. The GoI's Ministry of Statistics and Programme Implementation conveyed this in it's latest Project Summary Report, updated till March-end 2022. About the KAPP #3, it informed that,

The unit has generated about 402 MUs infirm power.
Required modifications/improvements based on commissioning feedback are in progress. This will be followed by further power raise and balance commissioning activities, with progressive regulatory clearances.
Incidentally, in it's earlier Report on November 2021 also, the power generated was stated as 402 MU.

via https://www.spansen.com/2022/04/npcil-h ... rapar.html

[kit]

Since the question refers to 700 MWe, I presume it is about India-developed- designed-and-built 700 MWe PHWRs. This is a fairly verbose response, hope the reader won't mind.

Good explanation ! .. thanks very much ., i was wondering since every major country has gone for higher capacity reactors in the past so why stick with 700 mw !! .. so is there a sweet spot for PHWR for capacity upgrade in the Indian context ? also how does this fit into the Thorium cycle .. we are yet to see full scale implementation of the FBR

https://www.spansen.com/2022/04/npcil-h ... rapar.html

23 Indian Power Reactors are, today, connected to the National Grid. In comparison, Sweden, operating only 6 Reactors generates the same amount. Alternately, South Korea, running 24 Reactors, outputs 23.09 Gwe, that is more than 3 times that of India. This is due to the fact that Indian Reactors are, primarily, of it's own design, small in capacity, that it's designers are incrementally evolving to larger-size builds - 220 & 540 MW-e PHWR. Sweden's 6 Reactors, a mix of PWR & BWR, on the other hand, each have an output of around 1000 MWe

[Hiten]

RAPS-7 will now go critical only in 2023, delayed by at least 1 more year.

In this petition, NPCIL had sought extension to draw power beyond June 2022, till when it currently has permission. This, ostensibly, points to prior plans of completing RAPS-7 by June 2022. It makes the case for drawing power for another year, till June 2023, to complete balance work & commence power generation.

via https://www.spansen.com/2022/04/raps-7- ... clear.html