India Nuclear News and Discussion 4 July 2011

[Amber G.]

^^^ Of course!(and delivery is free)- Dr. A. Sivathanu Pillai, (the founder, former CEO, and Managing Director of BrahMos Aerospace)
 
"Sir, for Pakistan, it's a free delivery item."

[Amber G.]

I posting a reply from the other dhaga here in the next post. For convenience and clarity, I am xposting it here.

My take:
From a purely strategic standpoint, India gains little by conducting another live test. The deterrent is credible, and the political costs are high. Nuclear tests today are more about signaling than design validation.

(India’s arsenal is already credible and survivable, with tested warheads and delivery systems. Another test might slightly improve confidence in new designs, but India doesn’t strictly need a test to maintain deterrence.)

(Alternatives: accelerate subcritical tests, refine delivery systems, or expand surveillance/command readiness — all without exploding a bomb.

Couldn't disagree more

1) If US tests, it will be stupid on our part not to. Political costs will be minimal, because we can be sure that China & Russia will
2) With innumerable tests, the US itself is not confident of just running simulations. We have barely enough data points and not nearly as sophisticated a simulation mechanism
3) Our H-bomb most likely underperformed. We need to not only retest it but also should test a mega-tonnage weapon. You cannot simulate your way out of a low-yield, likely-failed, single test while your desired yield in today's time is 100X
4) Yields --> warhead designs --> missile dimensions --> SSBN dimensions. We cannot afford to build SSBNs without having predictable thermonuclear yields in MIRV configuration

[SSridhar]

I largely agree with Prem Kumar.

There is always room for improvement in nuke designs that need to be tested physically, just as we do for missiles, fighters, naval assets etc. And, there cannot be a better opportunity than when others, who have signed the CTBT are themselves doing so. Of course, the US has not ratified it. But, we have not even signed it!

However, we should be careful wrt timing. A wait-and-watch approach as to how it all unfolds. Just as we did in 1998. Then, we waited until we had been completely pushed against the wall leaving us with no other option. But, for this potential second round of testing, we may not need to wait that long because of the changed/ever-changing circumstances.

[Mort Walker]

Amber G: Absolutely! — once they find a bomber that can carry a 100'sx 27-ton device, plus a few tons of depleted uranium tamper and lithium deuteride, without melting midair, and logistics team that doesn’t mind vaporizing the cockpit.

Plus, there’s the charming side-effect of atmospheric optics for decades — sunsets your city will never forget..

The Russian Poseidon nuclear torpedo is the revival of the Tsar Bomba. Of course initially with 2MT warhead, but the idea is to scale it up to 100MT.

As far as testing goes, the US & Russia have data going back to the late 1940s with over 1,700 tests. Subcritical tests are needed to understand how shaped charges and metallurgy works, refined delivery systems are also needed, and nuclear command/surveillance are also required. On top of that additional testing of enhanced radiation devices are needed along with higher yield warheads. The US used initially cryogenic cooled Li6-Deuterium and it's not clear what the USSR used, but Li7-D or other isotopes were later implemented. Whatever the case, India does NOT have enough data on fast neutron interaction with the 1998 Shakti tests. Considerable more work is needed. I would note that some data could from the neutron flow in the PFBR. Perhaps a new tamper design with other isotopes can yield a "Tsar Bomba" that is considerably lower weight.

[Amber G.]

^^^Thanks — I welcome the push. A few counters to think about before concluding that a live test is the obvious next move.

1) “If US tests, it will be stupid on our part not to — political costs minimal.”
Trump’s statement is a tweet, not policy - There’s no official U.S. decision to resume nuclear testing. So reacting to a tweet as if it’s a confirmed global restart might be premature.

Political costs are anything but minimal. After Pokhran-II India faced sanctions, diplomatic friction and strategic isolation for a period — costs that mattered to India’s economy and global diplomacy. That isn’t guaranteed to be neutralized simply because “China & Russia will.” Signalling parity is one thing; buying sanctions and supply-chain constraints is another.

2) “The US itself doesn’t trust simulations — innumerable tests show that.”
Not quite. The U.S. stopped explosive tests in 1992 precisely because stewardship programs (labs + supercomputers + subcritical experiments) gave sufficient confidence. The NNSA and national labs routinely combine high-fidelity physics codes, material science, archived test data and subcritical data to validate stockpiles. Yes, uncertainty remains — but that’s why we ought to invest in diagnostics, subcriticals and re-entry/flight tests, not atmospheric / underground blasts. The right question is: do we lack the specific data points required for the designs India needs today, or do we lack the capability to generate those points via non-explosive means? The answer is the former — solvable without a live test.

3) “Our H-bomb underperformed; must retest and test a megaton.”
That’s a heavy and testable claim. If { BIG if} India truly has evidence that an existing warhead is unreliable at yield, the technical fix path is: targeted diagnostics, material studies, subcritical experiments (to probe primaries), warhead redesign, and incremental flight testing of re-entry vehicles and fuzing. A megaton-class test is politically and technically overkill unless India is explicitly pursuing very large strategic yields (which it does not). Also, the technical marginal benefit of a single full-yield test is less than proponents imagine: one data point is noisy, hard to interpret alone, and can raise more questions than it answers.

“Yields → warhead → missile → SSBN. We can’t build SSBNs without predictable thermonuclear yields.”
Engineering an SSBN fleet is vast and costly; it doesn’t require detonating a device in the desert. What does matter for SLBM/SSBN work is integration testing: flight trials, cold launches, buoyant trials, MIRV separation tests, re-entry vehicle aerodynamics and hardening. Those are engineering and flight tests — already doable. For yield predictability you combine archived data, subcriticals and simulations. If your concern is MIRVing thermonuclear secondaries at precise yields, then a program of targeted subcritical work plus improved modelling and repeated flight/warhead separation trials gives far more practical returns than a politically explosive one-off.

My take earlier was on more on technical ground, and I understand that a live test is not a pure technical decision — it is political, economic, legal and strategic. Even if it provides some physics data, it also resets norms and invites counter-reactions. India’s strategic choices should therefore weigh the marginal technical gain of a detonation against the certain diplomatic and economic costs, and the alternatives (subcriticals, accelerated modelling, flight testing, improved survivability & command systems) are many and effective.

Testing may answers some physics questions for curious people but restraint answers a strategic one. Let’s be sure which question we’re trying to solve.

The survivable triad (land, air, sea) and credible (even fission only ) designs provide stability. The next frontier isn’t a bigger yield — it’s accuracy, command systems, and readiness.

=Amber G. A Trump tweet shouldn’t set off a seismic wave in the Thar Desert. (May be a 200 page BRF dhaga may be okay ).. Let’s wait for policy, not noise.

[Mort Walker]

1. Trump's tweets are the start of change of strategic thinking. India should be ready, but I agree not immediately after the US tests. It is assumed that the US will withdraw from the IUSCNA (123 Agreement) should India publicly speak out against US actions. So, all the pieces will have to be ready.

2. It's not the data, the science is solid. What isn't are the all engineering data for manufacturing. A crude analogy is that we know how Bernoulli's equation works for aircraft lift, therefore we don't need to test any aircraft designs and can easily build them.

3. A range of tests are needed to determine neutron flow for fusion-fission-fusion. I respectfully disagree with you on this.

4. People like the MAGAtards who are now in government & more will enter by 2030, need a swift kick in the pants reminder, "Don't Tread on Me". Yes, you are correct it is a political decision.

[Amber G.]

There is an article by Manoj Joshi .. also discussing how a potential shift in US nuclear policy—specifically President Trump's announcement about resuming nuclear weapons testing—presents a crucial opportunity for India to reassess and address a "known flaw" in its nuclear arsenal..ityadi.... Sharing:

Opportunity for India in US shift in nuclear policy

[Mort Walker]

There is an article by Manoj Joshi .. also discussing how a potential shift in US nuclear policy—specifically President Trump's announcement about resuming nuclear weapons testing—presents a crucial opportunity for India to reassess and address a "known flaw" in its nuclear arsenal..ityadi.... Sharing:

Opportunity for India in US shift in nuclear policy

Thanks. For others here this would probably be the time to revisit Robert Serber's "Los Alamos Primer" to get an initial understanding.

[Amber G.]

There is always room for improvement in nuke designs that need to be tested physically, just as we do for missiles, fighters, naval assets etc. And, there cannot be a better opportunity than when others, who have signed the CTBT are themselves doing so. Of course, the US has not ratified it. But, we have not even signed it!
..

Thanks.. and yes. True — there’s always room for refinement. But every design improvement doesn’t need a desert tremor. Modern diagnostics and subcritical work can do a lot quietly, just as we test missiles, fighters and naval platforms — the right kind of testing, without massive destruction. The key, as you said, is timing — and knowing when a signal helps more than it hurts.

[uddu]

There is always room for improvement in nuke designs that need to be tested physically, just as we do for missiles, fighters, naval assets etc. And, there cannot be a better opportunity than when others, who have signed the CTBT are themselves doing so. Of course, the US has not ratified it. But, we have not even signed it!
..

Thanks.. and yes. True — there’s always room for refinement. But every design improvement doesn’t need a desert tremor. Modern diagnostics and subcritical work can do a lot quietly, just as we test missiles, fighters and naval platforms — the right kind of testing, without massive destruction. The key, as you said, is timing — and knowing when a signal helps more than it hurts.

You are stating as if we have done 100s of such tests and every now and then its our hobby to do so. And for massive destruction we did not drop it on Nagasaki and Hiroshima. And for the Nuke tests, we must be doing it once they do it. Else we will be watching the U.S and China dominate with Nuke tests every now and then, while we be holding the Peace trophy to be awarded to Trump or Xi of whoever wins the Global Nuke Hegemon trophy.

[A_Gupta]

One strategic reason to test is to provoke Pakistan to test so that a clearer picture of Pakistan's nuke situation emerges.