All Things Nuclear

Not necessarily senseless. If a low-yield nuke is bad because it reduces the threshold to nuclear war, then the article itself mentions that America already has about 1000 such nukes. Adding a few more will not fundamentally change the picture in any way.

Then why create these new nukes? There's obviously an official explanation, which you can read here [1]:

"to address the conclusion that potential adversaries, like Russia, believe that employment of low-yield nuclear weapons will give them an advantage over the United States and its allies and partners. This supplemental capability strengthens deterrence and provides the United States a prompt, more survivable low-yield strategic weapon; supports our commitment to extended deterrence; and demonstrates to potential adversaries that there is no advantage to limited nuclear employment because the United States can credibly and decisively respond to any threat scenario."

But why are the new nukes necessary if the US already has 1000 low-yield nukes? The prior low-yields available were 0.3, 1.5, 5 and 10 kT TNT [2]. It appears that the new nuke, W76-2 has a yield that fits in the gap between 5 and 10kt (the exact yield is classified). More importantly though, the existing low-yield warheads are either gravity bombs (B61) or air-launched cruise missiles (AGM-86B). Launching them is a headache. Shifting these nukes from one military base to another is a headache. Just making the preparations necessary to launch these nukes…

The Union of Concerned Scientists has posted a great blog series "Role of Regulation in Nuclear Plant Safety." It's written by Dave Lochbaum, a degreed nuclear engineer who worked at American nuclear plants for 17 years. I think it's a better overview of NRC action and plant safety than any one incident. I've collected all the links here.

Series introduction: https://allthingsnuclear.org/dlochbaum/role-of-nuclear-regulation-intro

Flooding at Nine Mile Point: Regulation and Nuclear Power Safety #1 https://allthingsnuclear.org/dlochbaum/flooding-at-nine-mile-point

Three Mile Island Intruder: #2 https://allthingsnuclear.org/dlochbaum/three-mile-island-intruder

Empty Pipe Dreams at Palo Verde: #3 https://allthingsnuclear.org/dlochbaum/empty-pipe-dreams-at-palo-verde

Yankee Rowe and Reactor Vessel Safety: #4 https://allthingsnuclear.org/dlochbaum/yankee-rowe-and-reactor-vessel-safety

Flooding at a Florida Nuclear Plant: #5 https://allthingsnuclear.org/dlochbaum/flooding-at-a-florida-nuclear-plant

Containment Design Flaw at DC Cook Nuclear Plant: #6 https://allthingsnuclear.org/dlochbaum/containment-flaw-at-dc-cook

Pipe Rupture at Surry Nuclear Plant Kills Four Workers: #7 https://allthingsnuclear.org/dlochbaum/pipe-rupture-at-surry

Anticipated Transient Without Scram: #8 https://allthingsnuclear.org/dlochbaum/anticipated-transient-without-scram

Naughty and Nice Nuclear Nappers: #9 https://allthingsnuclear.org/dlochbaum/naughty-and-nice-nuclear-nappers

Breaking…

No country is going to risk that for two reasons in the current global context.

First, everyone will assume the payload is nuclear. Once the launch is detected, literally no one is going to even consider for a single moment that the missile might have a conventional payload. All actions, responses, and threat assessments are going to treat it as a nuke. If you're going to launch ICBMs at people, you might as well mount a nuke to it because the rest of the nuclear club is going to respond as if you had.

Second, the alert was for Hawaii. Given their isolation (they're over 7,500km from Korea), that means the missile is an ICBM. The Hwasong-15[0] can carry an estimated ~1,000kg payload, though it's unknown if it could do so for its full range.[1] That's tiny for a warhead. Mounting it on an ICBM, even if your country doesn't get blown to hell after launch, would just be a waste of money. The same goes for SLBMs as well. The only exception would be for precision strikes, but that's not really relevant to NK.

0. https://en.wikipedia.org/wiki/Hwasong-15

1. http://allthingsnuclear.org/dwright/nk-longest-missile-test-yet

What is the Secret Agreement between the United States and China on Taiwan?

https://allthingsnuclear.org/gkulacki/what-is-the-secret-agreement-between-the-us-and-china-on-taiwan

Nixon's Trip to China, The National Security Archive, Declassified, 2003:

https://nsarchive2.gwu.edu/NSAEBB/NSAEBB106/

Record of Historic Richard Nixon-Zhou Enlai Talks in February 1972 Now Declassified, ~. [See listed documents linked individually, for ex: https://nsarchive2.gwu.edu/nsa/publications/DOC_readers/kissinger/nixzhou/11-01.htm]

https://nsarchive2.gwu.edu/nsa/publications/DOC_readers/kissinger/nixzhou/

The One China Policy: What Would Nixon Do? (2017)

https://thediplomat.com/2017/01/the-one-china-policy-what-would-nixon-do/

Asia After Viet Nam, Richard Nixon, 1967 (pdf)

https://cdn.nixonlibrary.org/01/wp-content/uploads/2017/01/11113807/Asia-After-Viet-Nam.pdf

As far as the steam is concerned this puts my mind at a rest.
Quote from http://allthingsnuclear.org/post/3792741638/containment-at-fukushima
"In this situation, the vented air would be routed through a high-efficiency particulate air (HEPA) filter, charcoal beds, and another HEPA filter to remove as much radioactivity as possible before being released from a very tall stack to dilute the flow as much as possible."

When you say the contaminated water can be kept in the containment, does that mean that they are basically flooding the containment with seawater? My impression was that the there is still a need for cooling (i.e. cool water in, hot water out) in case of a total melt down.

Since the link to the source of the first table in that blog post does not work:

http://www.iaea.org/Publications/Magazines/Bulletin/Bull411/41104991518.pdf
(pdf, Wilson &al. IAEA Bulletin 41/1 1999)

Additionally, I recall that there are some problems with the estimate. For example it assumes that there are no more major accidents after Chernobyl. And he uses the WHO study, which may underestimate cancer fatalities by an order of magnitude. For a nice discussion of the problems of studies of Chernobyl see:

http://allthingsnuclear.org/how-many-cancers-did-chernobyl-really-cause-updated/