All Things NuclearAll Things Nuclear https://allthingsnuclear.org Insights on Science and Security Mon, 22 Jan 2018 18:12:42 +0000 en-US hourly 1 https://allthingsnuclear.org/wp-content/uploads/2016/01/cropped-favicon-32x32.png All Things Nuclear https://allthingsnuclear.org 32 32 Benny Hill Explains the NRC Approach to Nuclear Safety https://allthingsnuclear.org/dlochbaum/benny-hill-and-nuclear-safety https://allthingsnuclear.org/dlochbaum/benny-hill-and-nuclear-safety#comments Tue, 16 Jan 2018 11:00:17 +0000 https://allthingsnuclear.org/?p=15291 The Nuclear Regulatory Commission’s safety regulations require that nuclear reactors be designed to protect the public from postulated accidents, such as the rupture of pipes that would limit the flow of cooling water to the reactor. These regulations include General Design Criteria 34 and 35 in Appendix A to 10 CFR Part 50. Read More

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The Nuclear Regulatory Commission’s safety regulations require that nuclear reactors be designed to protect the public from postulated accidents, such as the rupture of pipes that would limit the flow of cooling water to the reactor. These regulations include General Design Criteria 34 and 35 in Appendix A to 10 CFR Part 50.

Emergency diesel generators (EDGs) are important safety systems since they provide electricity to emergency equipment if outside power is cut off to the plant—another postulated accident. This electricity, for example, would allow pumps to continue to send cooling water to the reactor vessel to prevent overheating damage to the core. So the NRC has requirements that limit how long a reactor can continue operating without one of its two EDGs under different conditions. The shortest period is 3 days while the longest period is 14 days.

An All Things Nuclear commentary in July 2017 described how the NRC allowed the Unit 3 reactor at the Palo Verde nuclear plant in Arizona to operate for up to 62 days with one of its EDGs broken, but had denied the Unit 1 reactor at the DC Cook nuclear plant in Michigan permission to operate for up to 65 days with one of its two EDGs broken. It was easy to understand why the NRC denied the request for DC Cook Unit 1 (i.e., 65 days is more than the 14-day safety limit). It was not easy to understand why the NRC granted the request for Palo Verde Unit 3 (i.e., 62 days is also more than the 14-day safety limit).

The NRC also granted a request on November 26, 2017, for the Unit 1 and 2 reactors at the Brunswick nuclear plant in North Carolina to operate for up to 30 days with one EDG broken.

NRC Inspection Findings and Sanctions 2001-2016

UCS examined times between 2001 and 2016 when NRC inspectors identified violations of federal safety regulations and the sanctions imposed by the agency for these safety violations. The purpose of this exercise was to understand the NRC’s position on EDGs and the safety implications of an EDG being inoperable.

As shown in Figure 1, NRC inspectors recorded 12,610 findings over this 16-year period, an average of 788 findings each year. The NRC characterized the safety significance of its findings using a green, white, yellow and red color-code with green representing findings having low safety significance and red assigned to findings with high safety significance. The NRC determined that fewer than 2% of its findings (242 in all) warranted a white, yellow, or red finding (“greater-than-green”).

Fig. 1 (Source: Union of Concerned Scientists)

NRC Greater-than-Green Inspection Findings and Sanctions 2001-2016

UCS reviewed ALL the greater-than-green findings issued by the NRC between 2001 and 2016 to determine what safety problems most concerned the agency over those years. Figure 2 shows the greater-than-green findings issued by the NRC binned by the applicable safety system or process. Emergency planning violations accounted for 22% of the greater-than-green findings over this period—the greatest single category. Other categories are shown in increasing percentages clockwise around the pie chart.

The 32 EDG greater-than-green findings between 2001 and 2016 constituted the second highest tally of such findings over this 16-year period—an average of two greater-than-green EDG findings per year. The NRC issued one Yellow and 31 White findings for EDG violations.

Fig. 2 (Source: Union of Concerned Scientists)

NRC Greater-than-Green EDG Inspection Findings and Sanctions 2001-2016

UCS reviewed all enforcement letters issued by the NRC for all 32 EDG greater-than-green findings to determine what parameters—particularly the length of time the EDG was unavailable—factored into the NRC concluding the findings had elevated safety implications. Several of the greater-than-green findings issued by the NRC involved EDGs being unavailable for less than the 62 days that the NRC permitted Palo Verde Unit 3 to continue operating with an EDG broken. For example:

  • The NRC issued a Yellow finding on August 3. 2007, because Kewuanee (WI) operated for 50 days with one EDG impaired by a fuel oil leak.
  • The NRC issued a White finding on September 19, 2013, because HB Robinson (SC) operated for 36 days with inadequate engine cooling for an EDG.
  • The NRC issued a White finding on June 2, 2004, because Brunswick (NC) operated for 30 days with an impaired jacket water cooling system for one EDG.
  • The NRC issued a White finding on April 15, 2005, because Fort Calhoun (NE) operated for 29 days for approximately 29 days with an inoperable EDG.
  • The NRC issued a White finding on December 7, 2010, because HB Robinson (SC) operated for 26 days with an impaired output breaker on one EDG.
  • The NRC issued a White finding on March 28, 2014, because Waterford (LA) operated for 25 days with inadequate ventilation for one EDG.
  • The NRC issued a White finding on December 18, 2013, because Duane Arnold (IA) operated for 22 days with inadequate lubricating oil cooling for one EDG.
  • The NRC issued a White finding on February 29, 2008, because Comanche Peak (TX) operated for 20 days with one EDG inoperable.
  • The NRC issued a White finding on December 7, 2007, because Fort Calhoun (NE) operated for 14 days with one EDG inoperable.
  • The NRC issued a White finding on April 20, 2007, because Brunswick (NC) operated for 9 days with an impaired lubricating oil system for one EDG.
  • The NRC issued a White finding on August 17, 2007, because Cooper (NE) operated for 5 days with a defective circuit card in the control system for one EDG.

NRC’s Cognitive Dissonance

The NRC issued 32 greater-than-green findings between 2001 and 2016 because inoperable or impaired EDGs increased the chances that an accident could endanger the public and the environment. As the list above illustrates, many of the NRC’s findings involved EDGs being disabled for 29 days or less.

Yet in 2017, the NRC intentionally permitted Palo Verde and Brunswick to continue operating for up to 62 and 30 days respectively.

If operating a nuclear reactor for 5, 9, 14, 20, 22, 26, or 29 days with an impaired EDG constitutes a violation of federal safety regulations warranting a rare greater-than-green finding based on the associated elevated risk to public health and safety, how can operating a reactor for 30 or 62 days NOT expose the public to elevated, and undue, risk?

Benny Hill to the Rescue

Fig. 3 (Source: www.alchetron.com)

Benny Hill was a British comedian who hosted a long-running television show between 1969 and 1989. On one of his shows, Benny observed that: “The odds against there being a bomb on a plane are a million to one, and against two bombs a million times a million to one.” Hence, Benny suggested that to be protected against being blown out of the sky: “Next time you fly, cut the odds and take a bomb” with you.

NRC’s allowing Palo Verde and Brunswick to operate for over 29 days with a broken EDG essentially takes Benny’s advice to take a bomb on board an airplane. Deliberately taking a risk significantly reduces the random risk.

But Benny’s suggestion was intended as a joke, not as prudent (or even imprudent) public policy.

So, while I’ll posthumously (him, not me) thank Benny Hill for much amusing entertainment, I’ll thank the NRC not to follow his advice and to refrain from exposing more communities to undue, elevated risk from nuclear power reactors operating for extended periods with broken EDGs.

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Lost in Space? The Zuma Satellite https://allthingsnuclear.org/lgrego/lost-in-space-the-zuma-satellite https://allthingsnuclear.org/lgrego/lost-in-space-the-zuma-satellite#comments Sat, 13 Jan 2018 11:00:25 +0000 https://allthingsnuclear.org/?p=15272 Many people awaited last Sunday’s Falcon 9 launch from Cape Canaveral of a highly classified US payload. The launch had been delayed for weeks, speculation as to the satellite’s purpose was rampant, and successfully delivering national security satellites to orbit is an important part of SpaceX’s business. Read More

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Many people awaited last Sunday’s Falcon 9 launch from Cape Canaveral of a highly classified US payload. The launch had been delayed for weeks, speculation as to the satellite’s purpose was rampant, and successfully delivering national security satellites to orbit is an important part of SpaceX’s business.

The launch, however, remains shrouded in mystery.

Shortly after the launch, Bloomberg reported that the satellite was lost, due to US Strategic Command saying they were not tracking any objects. The Wall Street Journal suggested that Congress was being briefed on a failure, and that it was due to a failure of the satellite to separate from the final stage, and so both were deorbited together.

A Verge story notes that neither SpaceX (the launcher) nor Northrop Grumman (the contractor who built the satellite) declared that the mission was a success after launch. SpaceX’s president said that the Falcon 9 “did everything correctly” and that they did not have a failure that requires investigation. Northrop Grumman stated that it does not comment on classified missions. Northrop Grumman provided the equipment that connects the satellite to the final rocket stage and that is eventually meant to separate them. So SpaceX’s claim that nothing went wrong with its end could be still be consistent with an overall failed mission.

What could the Zuma satellite be?

The Zuma satellite (USA280) is curious. It’s a classified satellite and so there’s no public description of its purpose. Satellite watchers usually pick up some clues about the purpose of a classified satellite by who made it and what orbit it is put in. For example, spy satellites that are imaging the ground in visible light often use sun synchronous orbits (close to a polar orbit) so that they can see the earth at a constant sun angle, which is helpful in detecting changes. Signals intelligence satellites tend to be at around 63 degrees inclination (the angle the orbit makes with respect to the equator).

Because there was no pre-launch announcement of orbital parameters, nor does the Space Track catalog provide them (it never does for such classified missions), we don’t know what orbit it was meant to go in exactly, but you can tell the approximate inclination by where the hazard zones are from its launch.

Marco Langbroek created this image of the Zuma launch hazard zone (in red in Fig. 1) for his blog:

Fig. 1 (Source: Marco Langbroek

This indicates that the satellite was launched in an orbit that was inclined around 50 degrees to the equator, similar to the International Space Station. Not many satellites use low earth orbits with 50 degree inclinations, except for satellites that were launched from the space station and so end up there. (See for yourself by sorting the satellites in the UCS Satellite Database.)

One other recent classified satellite, USA 276, was launched in that type of orbit, and it was launched in a similar direction as Zuma. That satellite was launched not only in the same orbital inclination as the ISS but also the same orbital plane. It was subsequently observed by the amateur observing community as having made a close approach to the ISS when it was performing docking maneuvers. Marco has a fascinating analysis in The Space Review about it.

What happened to it?

Zuma (USA 280) is still listed as a payload on orbit by the US space surveillance system (Fig. 2), as of this writing (January 12). So something made it into orbit and went around at least once. The object is listed as a payload and not as launch debris, indicating it is the satellite.

Fig. 2 (Source: Screen capture from Space Track)

Marco’s blog also reports sighting of the re-entry of an object that seems to square with the predicted time for the (intentional) de-orbit of the Falcon 9’s final stage, so that appears to no longer be in space. This is consistent with the successful placing into orbit of the satellite and the disposal of the last stage. (That’s good space “hygiene.”)

So there are a few possibilities:

  1. The Zuma satellite failed to separate from the final stage, and returned to earth along with the final stage and no satellite is in orbit. If this is the case, eventually the Space Track catalog will be updated and USA 280 will be removed. But this seems unlikely, since the satellite is still catalogued as being in orbit four days after launch. Edit: Jonathan McDowell makes two important points in his Jan 17 Space Report that I missed. One, a successful mission would likely have had two entries in the Space Track catalog—the payload as well as the final stage, which was scheduled to complete an orbit before being de-orbited. And two, that the catalog entries for classified national security satellites are not as a rule updated when those satellites become defunct or de-orbit. So the continued presence of the USA 280 entry doesn’t necessarily indicate anything except that an object from this launch made it into orbit, at least briefly.
  2. The satellite is in orbit. Indications this is the case would be that it remains in the catalog, and that amateur observers on the ground get a view of it. These observers use binoculars and telescopes to see satellites in reflected sunlight, and they are quite skilled at hunting satellites. However, they won’t get a chance to weigh in for a couple of weeks as the satellite won’t be optically visible in the regions of the northern hemisphere where most of them are. It’s possible that in the interim, the satellite will maneuver to another orbit, so finding it after a couple of weeks will be difficult.

Whether the satellite is functioning as intended would be difficult to tell, at least at first. If satellite watchers manage to see it and determine its orbital parameters over a period of time, they may be able to see whether it performs any maneuvers. An on-orbit maneuver is a positive sign that the satellite is at least alive, although doesn’t say whether it’s performing as designed. The lack of such maneuvers, especially if the satellite is in a relatively low orbit and would ordinarily need to compensate for atmospheric drag, can indicate that it is not functioning. Radars should be able to track the satellite, so presumably countries with space surveillance-capable radars, such as China and Russia, know quite a bit more about this already.

  1. While there is some precedent for using a launch failure as a cover story for a stealthy satellite (Misty), it’s hard to keep a satellite reliably hidden. (Note that the US has much more invested in space surveillance than other actors, so this would be even more difficult for countries other than the US.)

There are things that you can do to make it harder to see a satellite. You can minimize its radar reflectivity so that Russian and Chinese radars would have a harder time seeing it. You can minimize how reflective it is in the sunlight so that ground-based optical observers would have a hard time seeing it, too. Or you might make the satellite’s orbit unpredictable by maneuvering, so trackers must perform a time-consuming search for it each time they want to see it.

You’d probably need to do all these things at the same time to have hope of being stealthy for a significant period of time, and these techniques put a lot of constraints on the satellite itself. And one cannot credibly hope to stay stealthy indefinitely.

What’s curious about Zuma is that the bits of information don’t yet add up to a coherent story. There’s more information to come which may help—stay tuned!

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The Trump’s Adminstration’s Dangerous New Nuclear Policy https://allthingsnuclear.org/syoung/the-trumps-adminstrations-dangerous-new-nuclear-policy https://allthingsnuclear.org/syoung/the-trumps-adminstrations-dangerous-new-nuclear-policy#comments Fri, 12 Jan 2018 20:37:19 +0000 https://allthingsnuclear.org/?p=15270 Last night the Huffington Post released a draft version of the Trump administration’s Nuclear Posture Review, a deeply dangerous document that makes nuclear war more likely. UCS has a press statement on the draft, and below is a compilation of some additional quick thoughts on the draft, with more to come. Read More

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Last night the Huffington Post released a draft version of the Trump administration’s Nuclear Posture Review, a deeply dangerous document that makes nuclear war more likely. UCS has a press statement on the draft, and below is a compilation of some additional quick thoughts on the draft, with more to come.

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The Trident II D5 missile

The Trump NPR calls for a new, low-yield warhead for the Trident submarine-launched missile. The NPR premises the need for that warhead on the idea that the following systems will not be able to penetrate enemy air defenses to attack enemy targets:

  1. US dual-capable aircraft—including the new F35A stealthy fighter aircraft—armed with gravity bombs, including the new, high precision, low-yield B61-12;
  2. The dual-capable aircraft of allied countries in Europe that currently host US nuclear weapons;
  3. US B-2 stealth bombers armed gravity bombs, including the new B61-12;
  4. US B-52 bombers armed with air-launch cruise missiles and the future long-range standoff (LRSO) cruise missile, and
  5. the future B-21 “Raider” stealth bomber armed with gravity bombs and cruise missiles.

Seriously?

If that is the case, why are we spending hundreds of billions of dollars to deploy new stealthy nuclear-capable fighter aircraft and bombers, new gravity bombs, and new cruise missiles? The NPR calls for an unrealistic spending spree that is not justified by security needs.

+ + + + +

The Trump NPR significantly reduces the threshold for the use of nuclear weapons by explicitly listing a wide array of non-nuclear attacks on the United States that could constitute grounds for a US nuclear response, including attacks on civilians, infrastructure, nuclear forces, command and control, and early warning systems.

This is a dramatic change from the Obama administration’s nuclear policy, which explicitly sought to limit the roles and purposes of US nuclear weapons. It also reverses the trend of every administration since the end of the Cold War, Republican and Democratic alike. The Obama NPR set as a goal declaring that the sole purpose of US nuclear weapons is to deter a nuclear attack on the United States, its military forces, and its allies. It wanted to make nuclear war less likely. This document explicitly rejects that goal and in doing so makes nuclear use more likely.

The NPR also calls for tighter integration of nuclear and conventional forces. That deliberately blurs the line between the two and eliminates a clear nuclear fire break.

+ + + + +

The Trump NPR reverses the plan to retire the B83, a gravity bomb with a massive 1.2 megaton yield—by far the largest in the current US stockpile. Because the military had little use for this Cold War behemoth, the Obama administration had pledged to retire the B83 as soon as confidence was gained in the new B61-12 bomb, as a way to build support in Congress the for new B61. This document says it will keep the B83 “until a suitable replacement is identified.” That could be the B61-12, but there is no commitment to it.

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This document returns to the tired and inaccurate concept of “gaps” in US capabilities that ostensibly require new weapons systems to fill. President Kennedy campaigned on the idea of a “missile gap” when in fact it was the United States that had many more missiles than the Soviet Union. The document points to the “gap” in low-yield options that drive the need for new systems. But there is no “gap.” The US has multiple systems on multiple platforms able to deliver low-yield weapons.

+ + + + +

The document argues that Russia and China are modernizing their nuclear arsenals, and the United States is not. That is utter hogwash. The United States has been modernizing its forces consistently for the last several decades, but it has done so without building new systems. It has upgraded and improved the systems it already has. For example, a decade ago the United States still had submarines armed with Trident C4 missiles, which were not very accurate. Now, not only does every submarine carry the D5 missile, accurate enough to attack hardened targets, but those missiles are being updated, with newly built motors and improved guidance systems making them even more accurate. The W76-1 warheads on those missiles have also been improved, further increasing the ability to hold hardened targets at risk. And that system comprises the bulk of the US nuclear stockpile.

It’s also important to recognize that China’s nuclear arsenal remains tiny in comparison to the US arsenal. The United States has more than 1500 strategic warheads on three types of delivery systems. China has well fewer than 100 warheads on missiles capable of reaching the United States, and the warheads are not even mated to the missiles. They are fully de-alerted. There is zero comparison to US forces.

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Japan’s Role in the North Korea Nuclear Crisis https://allthingsnuclear.org/gkulacki/japans-role-in-the-north-korea-nuclear-crisis https://allthingsnuclear.org/gkulacki/japans-role-in-the-north-korea-nuclear-crisis#respond Thu, 11 Jan 2018 12:01:21 +0000 https://allthingsnuclear.org/?p=15239

Japanese Prime Minister Yukio Hatoyama (second from left) consults with US President Barack Obama during a 2010 summit on nuclear security.

During a recent trip to Japan I had the opportunity to discuss Japan’s role in the current North Korean nuclear crisis with Yukio Hatoyama, a former prime minister. Read More

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Japanese Prime Minister Yukio Hatoyama (second from left) consults with US President Barack Obama during a 2010 summit on nuclear security.

During a recent trip to Japan I had the opportunity to discuss Japan’s role in the current North Korean nuclear crisis with Yukio Hatoyama, a former prime minister. He led the Democratic Party of Japan (DPJ) to victory in September 2009, becoming the only Japanese politician to defeat the ruling Liberal Democratic Party (LDP) at the polls since end of the Second World War. 

The DPJ campaigned on wresting political and economic power away from an unelected bureaucracy and returning it to Japan’s elected representatives. Mr. Hatoyama’s perceived inability to deliver on that promise led to a loss of public support and his resignation as the leader of the DPJ in June of 2010. His party held on to power until they were defeated in September 2012 by a chastened LDP led by the current prime minister, Shinzo Abe.

Hatoyama is concerned about Abe’s approach to the North Korea nuclear crisis. He believes the current Japanese prime minister is providing unwise and provocative encouragement to US President Donald Trump’s threats to launch a pre-emptive military attack. Hatoyama is not alone in that assessment. Most of the Japanese I spoke with during my stay in Japan feel their government should be encouraging dialogue rather than cheerleading for pre-emptive US strikes that could ignite a wider war and invite North Korean retaliation against US military bases in Japan.

Yukio Hatoyama comes from a storied political family, and one of the wealthiest in the country. His father, Ichirō, served as foreign minister from 1976-77 under Prime Minister Takeo Fukuda. His grandfather, also named Ichirō, served three terms as prime minister from December 1954 through December 1956.

Although he retired from electoral politics in 2010, Mr. Hatoyama continues to promote what he believes may be his most important political legacy: the creation of an East Asian regional institution comparable to the European Union. His controversial efforts to advance the idea during his term in office troubled US Japan hands, who worried an Asian version of the EU would undermine the US-Japan relationship, especially since Hatoyama believes greater Japanese cooperation with China is an essential prerequisite for success.

UCS came to know Mr. Hatoyama through colleagues in the Japanese nuclear disarmament community. They were encouraged by his strong support for President Obama’s effort to reduce the role of nuclear weapons in US national security policy, including US security policy in Asia. Together with our non-governmental counterparts in Japan, UCS continues to work with Japanese legislators, the broad majority of whom, from all political parties, support responsible nuclear reductions.

We hope to bring more of their voices to the US debate about US nuclear weapons policy as President Trump’s Nuclear Posture Review unfolds later this year.

Our interview with Mr. Hatoyama was conducted in his Tokyo office on November 21, 2017. An audio file of the interview is available upon request.


 

UCS: Today we have the honor of speaking with Yukio Hatoyama, the former Prime Minister of Japan and the current Director of the East Asia Community Institute. Mr. Prime Minister thank you for taking the time to speak with us today.

I suppose we should start with the question of North Korea. How do you think about the way the United States and Japan are responding to what North Korea is doing?

Hatoyama: In regards to the North Korean development of nuclear missiles of course it is a reality that this is indeed a threat and in that sense countries around the world should be cooperating together and it may be necessary also to impose sanctions as is being done now. However, the final purpose for these sanctions should always be how to bring North Korea to the dialogue table.

Unfortunately, in Japan Prime Minister Abe has said that the time now for dialogue has finished, but I believe this is incorrect.

And, of course, when we consider why it is that North Korea has gone ahead to develop its missiles and nuclear weapons as well we need to recognize that fact that while there is a ceasefire agreement in place between the United States and North Korea, the war is not yet over, it’s still just in a state of ceasefire.

When we think about how North Korea is looking to create its own situation as well, it also sees the United States’ nuclear weapons and missiles – that are being maintained – being possessed – as well. And this is also leading it to seek its own nuclear and missile development program.

If we consider that North Korea is looking at its possession of these weapons as a tool for dialogue I think this really shows even more how the fact that dialogue now is more necessary than ever.

UCS: So, you think they are using it to start a dialogue with the United States?

Hatoyama: Yes, I do think so. And I believe it is necessary for us to recognize the fact that while North Korea knows that if they were to launch a nuclear weapon or missile towards the United States their own country, in turn, would be obliterated. They are aware of this. And, therefore, I don’t believe it’s likely they would actually make such an attack.

Therefore, I think instead we should understand their actions as looking at a way to try and seek negotiations with the United States which would allow them to have a more equal position between the two countries.

UCS: One of the things that members of Congress and the critics of the Trump administration’s policy towards North Korea have been discussing is the possibility of an accidental war… because of the rhetoric about the time for dialog being over… sending a signal to North Korea that military action is what happens when the time for dialogue is over.

Do you think Prime Minister Abe’s repeating that phrase about dialogue – the time for dialogue being over – is increasing the risk of an accidental miscalculation that could lead to a war with North Korea?

Hatoyama: Of course, from the part of President Trump, looking at how he mentioned having to consider all possibilities, including attacking through use of force. That is something which perhaps as a president should be considered.

However, this use of force cannot be the first option. That cannot be what is first gone to, whether it includes accidental use or not. Of course, if there were to be an accidental use of weapons by the United States on North Korea, North Korea would retaliate, in turn, against Seoul, against South Korea and against Japan. Of course, this would not be in the interest… not be good for Japan.

Now that Prime Minister Abe is repeatedly saying that the time for dialogue is over, the more he says this – the more he repeats this – the more the risk is increased as well. And this is also not in the interest of Japan.

UCS: A related issue in the United States is China’s role in this whole problem. A lot of American officials and the American media are highly critical of China because they don’t think they’re doing enough. What do you think about that?

Hatoyama: I believe that rather than looking at…criticizing China in terms of its role … or what role it is or is not playing … the fundamental issue at stake here is an issue between the United States and North Korea. China, Japan and South Korea are therefore not central players in this but have the role of looking at how they can cooperate together between these countries to create the conditions and space for negotiations between the United States and North Korea as the two key players in this issue.

Of course, China and these other countries they themselves do not desire a war to break out. While some may be criticizing China for being too generous or too kind towards North Korea, rather we should be looking at how to have more cooperation between China, Japan and South Korea in order to bring the United States and North Korea to the negotiations table.

UCS: Well the main issue is that people in the United States want them to cut off oil and food. Do you think that’s a good idea?

Hatoyama: I believe that cooperation in the direction of sanctions is to an extent necessary. However, we also need to recognize that if North Korea is pushed too far into a corner then it’s unclear what actions they might take, and what means they might take to do this.

When we also consider Japan’s history as having been on the receiving side of economic sanctions – which actually contributed to Japan’s path towards waging the wrong war in the past century as well, this is something that we need to learn from history and recognize that strict sanctions can… well, do not necessarily always lead to positive results. They can actually lead to such negative results as well.

China is saying it will to an extent cooperate as part of the international community on the increase or strengthening of sanctions. We also need to make sure that this is not done in order to, well, let the people of North Korea completely starve. On the contrary, we need to look at what the purpose of this is.

UCS: Well I know our time here today is limited so I have just one final related question, and we’ll just keep the focus on North Korea. And that is the domestic political aspects of the North Korea question in Japan. I was invited to listen from the gallery to Prime Minister Abe’s speech to the Diet last week. North Korea seemed to be a prominent part of the speech. He conveyed the idea that this was an important issue in the last election. Was it? And do you think there is anything that the opposition, in Japan, can do to sort of change the Japanese view of the North Korea question.

Hatoyama: Unfortunately, in the recent election Prime Minister Abe was re-elected by bringing this idea of the threat of North Korea to the fore, and saying this is why we need a stable government in place. This was used to convince the people to vote in favor for him in this past election.

I believe that whether it’s President Trump or any American president, the policy of Japan, which is now being put forward by Prime Minister Abe, following the United States administration fully in its policies is not going to be the way to resolve any kind of issue including the issue of North Korea as well.

When we look at the policy…or Prime Minister Abe stating that the time for dialogue is over.. we’re merely following US policy in regard to North Korea. This is not the way to be able to resolve this issue. Rather, Japan needs to be looking at how it can play a role in bringing the United States and North Korea to the negotiations table, and aim in this direction. This is the direction in which the government should be aiming and the opposition parties should also be pushing the government towards this and encouraging this as well.

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An Ounce of Prevention…is Worth a Kiloton of Cure https://allthingsnuclear.org/dwright/an-ounce-of-prevention https://allthingsnuclear.org/dwright/an-ounce-of-prevention#comments Mon, 08 Jan 2018 18:14:38 +0000 http://allthingsnuclear.org/?p=15228 As part of its ongoing online training system, the Centers for Disease Control and Prevention (CDC) has scheduled a webinar later this month titled “Public Health Response to a Nuclear Detonation.”

The description of the webinar on the CDC website says: “While a nuclear detonation is unlikely, it would have devastating results and there would be limited time to take critical protection steps. Read More

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As part of its ongoing online training system, the Centers for Disease Control and Prevention (CDC) has scheduled a webinar later this month titled “Public Health Response to a Nuclear Detonation.”

The description of the webinar on the CDC website says: “While a nuclear detonation is unlikely, it would have devastating results and there would be limited time to take critical protection steps. Despite the fear surrounding such an event, planning and preparation can lessen deaths and illness.”

(Source: CTBTO)

On the one hand

This makes some sense. With global stockpiles of more than 15,000 nuclear weapons in the hands of nine countries around the world, thinking through the consequences of their use is the responsible thing for the CDC to do instead of pretending the world will make it through another few decades without someone detonating a nuclear weapon.

Nuclear use is a particular concern now given the flare-up of tension between North Korea and the United States and the bombastic threats by Kim Jong-un and President Trump (not to mention their recent boasts about their “nuclear buttons”).

Perhaps even more likely is a nuclear war by accident. The United States keeps hundreds of missile-based nuclear warheads on hair-trigger alert with the option of launching them very quickly if early warning sensors report a Russian attack. Russia is believed to do the same. But technical and human mistakes over the past decades have led to a surprising number of cases in which one or the other country thought an attack was underway and started the process to launch a nuclear retaliation. How long until one of those mistakes doesn’t get caught in time?

The use of nuclear weapons could have horrific results. Many US and Russian warheads have explosive yields 20 to 40 times  larger than those of the warheads that destroyed Hiroshima and Nagasaki in 1945.

Because North Korean missiles are not very accurate, it would need to aim its nuclear weapons at large targets, namely big cities. While the United States does not intentionally target cities, many of its warheads are aimed at military or industrial targets that are in or near major population centers. The same is true for Russian targets in the United States.

In addition, a nuclear detonation could have world-wide consequences. Studies have shown that even a relatively limited nuclear exchange between India and Pakistan for example, could eject so much soot into the atmosphere that there would be significant global cooling for a decade. This “limited” nuclear winter could lead to widespread starvation and disease.

So, on the other hand…

A key message of the CDC briefing will hopefully be that the role public health professionals can play following a nuclear attack is relatively small, and the only real option is to prevent the use of nuclear weapons in the first place. This is a case where an ounce of prevention is worth much more than a kiloton of cure.

Given that reality, there are several steps the United States should take to reduce the risk of nuclear use, including:

  1. Pursuing diplomacy with North Korea, with the immediate goal of reducing tensions and the risk of military attacks, and a longer term goal of reducing Pyongyang’s nuclear arsenal. Secretary of State Rex Tillerson has made clear repeatedly that he would like to do this. President Trump should get out of his way and let him.
  2. Eliminating the option of launching nuclear weapons on warning of an attack and taking all missiles off hair-trigger alert.
  3. Changing US policy so that the only purpose of US nuclear weapons is to deter, and if necessary respond to, the use of nuclear weapons by other countries. Under this policy, the United States would pledge to not use nuclear weapons first.
  4. Scaling back the $1.2 trillion plan to rebuild the entire US nuclear arsenal over the next 30 years.
  5. Starting negotiations on deeper nuclear cuts with Russia and taking steps toward a verifiable agreement among nuclear-armed states to eliminate their nuclear arsenals.
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New Update of the UCS Satellite Database https://allthingsnuclear.org/lgrego/ucs-satellite-database-update-8-31-17 https://allthingsnuclear.org/lgrego/ucs-satellite-database-update-8-31-17#respond Sat, 06 Jan 2018 16:33:47 +0000 http://allthingsnuclear.org/?p=15225 A newly updated version of the UCS satellite database was released this fall, including launches through the end of the summer. The total number of operating satellites is now 1,738.

The changes to this version of the database include: the addition of 321satellites, the deletion of 35 satellites, and, as always, the addition of and corrections to some satellite data. Read More

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A newly updated version of the UCS satellite database was released this fall, including launches through the end of the summer. The total number of operating satellites is now 1,738.

The changes to this version of the database include: the addition of 321satellites, the deletion of 35 satellites, and, as always, the addition of and corrections to some satellite data.

The number of active satellites has historically grown modestly over time, since the newly-launched satellites are balanced by those that are de-orbited or have become inactive. But this quarter, 321 new satellites were added to the database, a record by far. While sheer numbers are growing, it’s also important to keep in perspective that much of this growth is in small satellites. For example, nearly half of the new satellites were Planet Labs’ Doves, part of a constellation of small satellites designed to provide constant, timely imagery of the earth’s surface. Dozens of others were Spire’s Lemur small satellites, providing commercial weather and ship-tracking services. Also launched were 20 new Iridium NEXT low earth orbit communications satellites. These satellites, at 860 kg launch mass, weigh as much as 86 Lemur satellites or 215 Doves.

In any case, it seems clear that the growth in numbers of satellites won’t be as slow as it used to be, and may accelerate quite a bit in the future. In 2016, commercial companies filed for a U.S. Federal Communications Commission license for 8,731 non-geostationary communications satellites, including 4,425 for SpaceX, nearly 3,000 for Boeing, and 720 for OneWeb.

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China in Focus #20: A Chinese Communist Christmas https://allthingsnuclear.org/gkulacki/china-in-focus-20-a-chinese-communist-christmas https://allthingsnuclear.org/gkulacki/china-in-focus-20-a-chinese-communist-christmas#respond Mon, 18 Dec 2017 09:05:58 +0000 http://allthingsnuclear.org/?p=15182  

There is no war on Christmas here. The word—all nine letters of it—is everywhere. Communist Party Chairman Xi Jinping may be reprising classic communist iconography in bookshops and on the telly, but in the shopping malls, where an awful lot of Chinese people seem to spend an awful lot of their time, the signs of the season are everywhere. Read More

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There is no war on Christmas here. The word—all nine letters of it—is everywhere. Communist Party Chairman Xi Jinping may be reprising classic communist iconography in bookshops and on the telly, but in the shopping malls, where an awful lot of Chinese people seem to spend an awful lot of their time, the signs of the season are everywhere.

It is hard to be afraid of a country and a culture that has so wholeheartedly embraced one of my favorite holidays. Its religious roots are probably a mystery to most. Nothing is harder to explain to Chinese family and friends than Christianity, especially after I tell them I was raised a Catholic, which is considered an entirely different religion here. Nevertheless, the general sense that Christmas is a celebration of unity, peace, family, friends and charity seems well understood. “It’s like Chinese New Year for Westerners.” Amen comrade.

It wasn’t always this way. When I first came to China in 1984 the toughest emotional moment of entire experience was making the mistake of trying to sing “I’ll be Home for Christmas” to the foreign student assembly. We did our best to make a day of it, but there was not a Christmas creature stirring anywhere outside our dorm. Decades of anti-Western Chinese Communist Party (CCP) propaganda had wiped almost every vestige of the holy day from “mainland” China’s collective memory.

It is interesting how quickly Christmas came back and how pervasive it has become. US China pundit Bill Bishop recently published a cynical missive championing the proposition that Americans should finally surrender the “fantasy” that China could ever become “more like us.” I read it while listening to Nat King Cole’s rendition of “O Holy Night” playing in a Shanghai Starbucks. After all the time I’ve spent here I’ve come to wonder whether Chinese and Americans were ever really all that different to begin with. Cultural differences are very real, but so are the universal human values – like love and family – that cultures embody. Christmas, if left undisturbed by political authority, seems to appeal to everyone.

To be sure, the mass marketing of global corporations plays a major role, larger than that of any organized church (Sorry @Pontifex). But that does not make the phenomenon any less real. Commerce has always been the carrier of culture. Governments can respond to global commercial and cultural trends in a variety of ways. Given Chairman Xi’s exceptional attempt to micromanage the evolution of modern Chinese culture, especially his unrelenting efforts to mediate its contact with the outside world, the ubiquity of Christmas in Xi’s China is a welcome sign.

It doesn’t prove anything, of course. But it does suggest that left to our own devices us ordinary people, enjoying the same coffee, cakes and carols this holiday season, whether we’re in, or from, Baltimore or Beijing, may not be as different as our pundits and politicians tell us we are.

Defending what we imagine to be “our” cultures from the supposed predations of “other” cultures seems to be a hallmark of what might be called post-globalization politics. The late US political theorist Samuel Huntington described it as a “clash of civilizations.” The idea that the United States is losing a global battle for cultural supremacy seems to be what animates political figures like Steve Bannon, Mike Flynn, President Trump and many of the voters who’ve rallied to their warnings about the rise of China and the decline of Western civilization.

The Chinese communist embrace of Christmas is an interesting refutation of Huntington’s “us” or “them” depiction of how culture operates in the interconnected world wrought by global commerce and its technologies. Christmas is no longer “ours.” It’s “theirs” too. Perhaps that’s because the essential cultural content is universal.

I had a related experience with Mozart in Vienna this summer. My wife, who is Chinese, was chatting with a hawker selling tickets to a concert in the Musikverein, or the 金色大厅, as the Chinese call it. The young man, a violinist, made his pitch in respectable Chinese. He also noted that Chinese attendance at performances of western classical music was underwriting the lives of a lot of young musicians in the city. Sure enough, the 金色大厅was chock full of Chinese tourists, whose enthusiasm for the music lifted the spirits of everyone else in the room, performers included. Is Mozart a product of “Western” culture that needs to be protected from a rising China? Or has a rising China’s embrace given new life to old art that belongs to us all?

Globalization has its problems. Rising economic inequality is the most pressing. Our political leaders should focus on that, rather than fretting about the future of human culture, which, if Christmas in communist China is any indication, we can sort out better by ourselves.

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Pressuring China on North Korea Could Be a Mistake https://allthingsnuclear.org/gkulacki/pressuring-china-on-north-korea-could-be-a-mistake https://allthingsnuclear.org/gkulacki/pressuring-china-on-north-korea-could-be-a-mistake#comments Mon, 11 Dec 2017 12:00:27 +0000 http://allthingsnuclear.org/?p=15124

The Trump administration is intentionally putting China in very tough spot. It is attempting to make the Chinese leadership believe it must choose between a preemptive US attack on North Korea or agreeing to US requests to strangle North Korea’s economy with even tougher sanctions, including cutting off North Korea’s oil supply at the beginning of winter. Read More

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The Trump administration is intentionally putting China in very tough spot. It is attempting to make the Chinese leadership believe it must choose between a preemptive US attack on North Korea or agreeing to US requests to strangle North Korea’s economy with even tougher sanctions, including cutting off North Korea’s oil supply at the beginning of winter. That may seem like clever diplomacy to some. But it’s a high stakes game of poker that the United States could lose.

The problem with the Trump administration’s strategy – if it is a strategy – is that from China’s point of view both choices lead to war.

China’s Bad Hand

Chinese arms control analysts do not believe North Korea is willing to give up its nuclear weapons program. Moreover, they think the uptick in threatening US language and military posturing have led the North Koreans to accelerate their efforts to develop a credible nuclear deterrent. In their view, the Trump administration’s policy of “maximum pressure” is pushing North Korea farther away from the negotiating table, not towards it.

Chinese scholars do not believe the Chinese leadership can influence North Korean decisions about security. One of the most often repeated laments I’ve heard from Chinese colleagues during this visit is that Americans don’t understand that China is not North Korea’s ally. North Korea does not trust China. It never has. Chinese historians are quick to point out that even during the Korean War in the 1950s the North Korean leadership resisted Chinese military intervention. And because North Korea does not trust China, the Hermit Kingdom’s nuclear weapons program is the only credible security guarantee it’s got. It is also the only bargaining chip the North Koreans can use to encourage the United States to negotiate, and then honor, a permanent peace treaty.

Chinese military experts do not believe US preemption will succeed. They think the North Korean leadership, and the nuclear weapons program, will survive a surgical strike. In their view, only a massive US attack, accompanied by a ground invasion, has a chance of permanently disarming the North Koreans. Moreover, Chinese military analysts believe that any US attack, no matter how limited, will precipitate North Korean retaliation. That will invite additional US attacks and begin a downward spiral of military activity that will be very hard to stop once it starts.

What does China believe? The Chinese government has stated, on multiple occasions, that severe sanctions, like cutting off oil and food supplies, will “destabilize” the peninsula. That’s the diplomatic way of saying it will lead to war. Chinese analysts do not rule out the possibility that North Korea might decide to punish China for capitulating to the United States. A Chinese military response to any North Korean attack against China risks inviting unwanted US military involvement. Alternatively, a North Korean military attack against South Korea or Japan would compel US military action. Either way, Chinese experts believe the same pattern of escalating attacks and retaliation will ensue.

So, if the Trump administration isn’t bluffing about preemption, and the Chinese leadership believes preemption and sanctions both lead to war, the only real choice China faces is how it should respond to this no-win situation.

Possible Chinese Responses

Like most people faced with impossible choices, China’s leaders will probably try to put things off as long as they can. They will try to give the Trump administration a little more on sanctions and hope that’s enough to keep things quiet a bit longer. At some point, however, when sanctions begin to have a meaningful effect on North Korea, China’s leaders will likely conclude they cannot apply additional pressure without triggering a North Korean military provocation.

Some of the Chinese experts advising President Xi think that time has already come. They are the ones behind the Global Times editorial that threatened Chinese military intervention if the United States fires the first shot. These Chinese hard-liners are now trying to bring Russia on board with discussions about a joint statement warning the Trump administration against a preemptive attack on North Korea. They do not believe the United States is willing to risk a war with China and Russia to attempt a preemptive strike against North Korea that has a low probability of success.

Other Chinese experts don’t want the leadership to take such a huge step backwards and revert to a Cold War-style relationship with the United States. They agree there is no reason to expect North Korea to freeze or dismantle its nuclear weapons program, and that tightened sanctions and increased pressure only strengthen North Korean resolve. Nevertheless, they would rather work with the United States than against it. A tiny minority of those experts would even like the Chinese leadership to consider cooperating with the United States on military action against North Korea.

Likely Outcomes

The chance of that happening is probably quite small. Chinese cooperation in US military action against North Korea would invite North Korean retaliation against China. And China’s leaders have good reason to doubt whether there will be any meaningful reciprocation from the Trump administration in exchange for taking such a huge risk. Chinese military and foreign policy analysts presume the United States will still see China as a rising economic and military threat. Moreover, the Trump administration’s notorious unpredictability would make any US promise unreliable.

Because the choice the United States is presenting to China is so unpalatable, the most likely Chinese response will be to wait out the storm and hope Trump is bluffing. US efforts to ratchet up inflammatory rhetoric and military exercises are unlikely to alter Chinese thinking. Chinese leaders have been confronting US threats and enduring US military posturing for decades. Moreover, there is a tendency in traditional Chinese military culture to believe that preparations for actual military moves are concealed, while advertised preparations, like anchoring a nuclear submarine in South Korea, or practicing air strikes, are for show. Mainstream Chinese interpretations of post-1949 US-China relations reinforce that tendency. From China’s point of view, the Trump administration’s threat to start a war with North Korea looks like a bluff.

If the Trump administration is bluffing, and the Chinese government manages to keep its cool, what happens then? Will China look like the wiser party? Will Japan and South Korea lose faith in Trump’s judgment? It is possible that instead of backing China into a corner, President Trump may find himself trapped in a situation where he feels he has to attack North Korea just to preserve his credibility in Asia.

It would not be the first time a US president fell into this trap. President Eisenhower got stuck in the same conundrum during the Taiwan Straights Crisis of 1954-55. The Joint Chiefs argued the United States had to attack China, and risk nuclear war with the Soviet Union, to preserve US credibility in the region. But Ike was a general too, understood the nature of war, and chose to subordinate concerns about credibility to caution and wait. He chose wisely. How President Trump would respond is a question worth pondering before pushing the strategy of “maximum pressure” to the breaking point.

 

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Reentry of North Korea’s Hwasong-15 Missile https://allthingsnuclear.org/dwright/reentry-of-hwasong-15 https://allthingsnuclear.org/dwright/reentry-of-hwasong-15#comments Thu, 07 Dec 2017 19:53:50 +0000 http://allthingsnuclear.org/?p=15130 Photos of the Hwasong-15 missile North Korea launched on its November 29 test suggest it is considerably more capable than the long-range missiles it tested in July. This missile’s length and diameter appear to be larger by about 10 percent than July’s Hwasong-14. Read More

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Photos of the Hwasong-15 missile North Korea launched on its November 29 test suggest it is considerably more capable than the long-range missiles it tested in July. This missile’s length and diameter appear to be larger by about 10 percent than July’s Hwasong-14. It has a significantly larger second stage and a new engine in the first stage that appears to be much more powerful.

While we are still working through the details, this strongly implies that North Korea could use this missile to carry a nuclear warhead to cities throughout the United States. A final possible barrier people are discussing is whether Pyongyang has been able to develop a reentry vehicle that can successfully carry a warhead through the atmosphere to its target, while protecting the warhead from the very high stresses and heat of reentry.

Here are my general conclusions, which I discuss below:

  1. North Korea has not yet demonstrated a working reentry vehicle (RV) on a trajectory that its missiles would fly if used against the United States.
  2. However, there doesn’t appear to be a technical barrier to building a working RV, and doing so is not likely to be a significant challenge compared to what North Korea has already accomplished in its missile program.
  3. From its lofted tests, North Korea can learn significant information needed for this development, if it is able to collect this information.
  4. While the United States put very significant resources into developing sophisticated RVs and heatshields, as well as extensive monitoring equipment to test them, that effort was to develop highly accurate missiles, and is not indicative of the effort required by North Korea to develop an adequate RV to deliver a nuclear weapon to a city.

The Hwasong-15 RV

When the photos appeared after North Korea’s November 29 missile launch, I was particularly interested to see the shape of the front of the missile, which gives information about the reentry vehicle (RV). The RV contains the warhead and protects it on its way to the ground. It appears the Hwasong-15 is carrying an RV that is considerably wider and blunter than that on the Hwasong-14 (Fig. 1).

Fig. 1. The RVs for the Hwasong-14 (left) and Hwasong-15 (right), roughly to scale. (Source: KCNA)

This fact has several implications. A blunter RV can clearly accommodate a larger diameter warhead, and the warhead can sit farther forward toward the nose of the RV. This moves the center of mass forward and makes the RV more stable during reentry. (This drawing shows how the cylindrical nuclear weapon in the US Titan RV, which was roughly the same size and shape, although much heavier, than the Hwasong-15 RV may be.)

A blunter nose on the Hwasong-15 RV also helps protect it from high atmospheric forces and heating during reentry. Here’s why:

As the RV enters the atmosphere, drag due to the air acts as a braking force to slow it down, and that braking force puts stress on the warhead. At the same time, much of the kinetic energy the RV loses as it slows down shows up as heating of the air around the RV. Some of that heat is transferred from the air to the RV, and therefore heats up the warhead. If the stress and/or heating are too great they can damage the RV and the warhead inside it.

A blunter RV has higher drag and slows down in the thin upper parts of the atmosphere more than does a slender RV, which continues at high speed into the thick lower parts of the atmosphere. This results in significantly less intense stress and heating on the blunter RV. In addition to that, a blunt nose creates a broad shock wave in front of the RV that also helps keep the hot air from transferring its heat to the RV.

Fig. 2. This shows two low-drag RVs being placed on a Minuteman III missile, which can carry three RVs. (Source: US Air Force).

A rough estimate shows that if the RVs had the same mass and flew on the same trajectory, the peak atmospheric forces and heating experienced by an RV similar in shape to the Hwasong-14 nosecone in Fig. 1 would be roughly four or more times as great as that experienced by a blunter Hwasong-15 RV; those on a modern US RV, like that on the Minuteman III missile (Fig. 2), might be 20 times as large as on the Hwasong-15 RV.

The tradeoff of having a blunt warhead is that when the RV travels more slowly through the atmosphere it reduces its accuracy. In order to get very high accuracy with its missiles, the United States spent a tremendous amount of effort developing highly sophisticated heatshields that could withstand the heating experienced by a slender, low-drag RV.

For North Korea, the decrease in accuracy due to a blunt RV is not particularly important. The accuracy of its long-range missiles will likely be tens of kilometers. That means that it would not use its missiles to strike small military targets, but would instead strike large targets like cities. For a large target like that, the reduction in accuracy due to a blunt RV is not significant.

What could North Korea learn from its recent test?

Press stories report US officials as saying that the reentry vehicle on North Korea’s November 29 test “had problems” and “likely broke up” during reentry. If true, this implies that the RV used on this flight could not withstand the strong drag forces as the RV reached low altitudes.

It’s worth noting that the drag forces on the RV during reentry on the lofted trajectory would be more than twice as great as they would be on a standard trajectory of 13,000 km range flown by the same missile (Fig. 3). This is because on the flatter trajectory, the RV flies through a longer path of thin air and therefore slows down more gently than on the lofted trajectory. It is therefore possible the RV might survive if flown on a standard trajectory, but North Korea has not yet demonstrated that it would.

However, given the estimated capability of the Hwasong-15 missile, North Korea appears to have the option of strengthening the RV, which would increase its mass somewhat, and still be able to deliver a warhead to long distances.

Fig. 3. This figure shows the atmospheric forces on the RV with altitude as it reenters, for the highly lofted test on November 29 (black curve) compared to the same missile flying a 13,000 km standard  trajectory (a minimum-energy trajectory, MET). The horizontal axis plots the product of the atmospheric density and square of the RV speed along its trajectory, which is proportional to the drag force on the RV. The calculations in all these figures assume a ballistic coefficient of the RV of 100 lb/ft2 (5 kN/m2). Increasing the ballistic coefficient will increase the magnitude of the forces and move the peaks to somewhat lower altitudes, but the comparative size of the curves will remain similar.

The situation is similar with heating of the RV. The last three columns of Fig. 4 compare several measures of the heating experienced by the RV on the lofted November 29 test to what would be experienced by the same RV on a 13,000 km-range missile on a standard trajectory (MET).

Fig. 4. A comparison of RV forces and heating on the November 29 test and on a 13,000 km-range trajectory, assuming both missiles have the same RV and payload. A discussion of these quantities is given in the “Details” section below.

These estimates show that the maximum heating experienced on the lofted trajectory would be about twice that on a standard trajectory, but that total heat absorbed by the RV on the two trajectories would be roughly the same. Because the heating occurs earlier on the RV on the standard trajectory than on the lofted trajectory, that heat has about 130 seconds to diffuse through the insulation of the RV to the warhead, while the heat on the lofted trajectory diffuses for about 80 seconds (Fig. 5). This somewhat longer time for “heat soak” can increase the amount of heat reaching the warhead, but North Korea would put insulation around the warhead inside the RV, and the heat transfer through insulators that North Korea should have access to is low enough that this time difference is probably not significant.

Fig. 5: This figure shows how the heating rate of the RV surface varies with time before impact on the lofted and standard trajectory. The areas under the curves are proportional to the total heat absorbed by the RV, and is only about 20% larger for the MET. The vertical axis plots the product of the atmospheric density and the cube of the RV speed along its trajectory, which is proportional to the heating rate on the RV.

Fig. 6 shows heating on the two trajectories with altitude.

Fig. 6. This figure shows the heating of the RV with altitude as it reenters.

These results show that if North Korea were able to demonstrate that its RV could survive the peak drag forces and heating on a lofted trajectory, it should also be able to survive those on a standard trajectory. As noted above, the estimated capability of the Hwasong-15 missile suggests North Korea would be able to increase the structural strength of the RV and its heat shielding and still be able to deliver a warhead to long distances.

There is still some question about what information North Korea may actually be getting from its tests. One advantage of testing on highly lofted trajectories that fall in the Sea of Japan is that the RV can presumably radio back data to antennae in North Korea for most of the flight. However, because of the curvature of the Earth, an antenna on the ground in North Korea would not be able to receive signals once the RV dropped below about 80 km altitude at a distance of 1000 km. To be able to track the missile down to low altitudes it would likely need a boat or plane in the vicinity of the reentry point.

Some details

The rate of heat transfer per area (q) is roughly proportional to ρV3, where ρ is the atmospheric density and V is the velocity of the RV through the atmosphere. Since longer range missiles reenter at higher speeds, the heating rate increases rapidly with missile range. The total heat absorbed (Q) is the integral of q over time during reentry. Similarly, forces due to atmospheric drag are proportional to ρV2, and also increase rapidly with missile range.

The calculations above assume a ballistic coefficient of the RV equal to 100 lb/ft2 (5 kN/m2). The ballistic coefficient β = W/CdA (where W is the weight of the RV, Cd is its drag coefficient, and A is its cross-sectional area perpendicular to the air flow) is the combination of parameters that determines how atmospheric drag reduces the RV’s speed during reentry. The drag and heating values in the tables roughly scale with β. A large value of β means less atmospheric drag so the RV travels through the atmosphere at higher speed. That increases the accuracy of the missile but also increases the heating. The United States worked for many years to develop RVs with special coatings that allowed them to have high β and therefore high accuracy, but could also withstand the heating under these conditions.

Based on the shape of the front of the Hwasong-15, I estimate that the drag coefficient Cd of its RV is 0.35-0.4. That value gives β in the range of 100-150 lb/ft2 (5-7 kN/m2) for an RV mass of 500-750 kg. The drag coefficient of an RV similar in shape to the front of the Hwasong-14 is about 0.15.

Updated 12/8/17.

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Did Pilots See North Korea’s Missile Fail during Reentry? https://allthingsnuclear.org/dwright/did-pilots-see-nk-missile-fail https://allthingsnuclear.org/dwright/did-pilots-see-nk-missile-fail#respond Tue, 05 Dec 2017 16:07:56 +0000 http://allthingsnuclear.org/?p=15114 News reports say that a Cathay Airlines flight crew on November 29 reported seeing North Korea’s missile “blow up and fall apart” during its recent flight test. Since reports also refer to this as happening during “reentry,” they have suggested problems with North Korea’s reentry technology. Read More

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News reports say that a Cathay Airlines flight crew on November 29 reported seeing North Korea’s missile “blow up and fall apart” during its recent flight test. Since reports also refer to this as happening during “reentry,” they have suggested problems with North Korea’s reentry technology.

But the details suggest the crew instead saw the missile early in flight, and probably did not see an explosion.

One report of the sighting by the Cathay CX893 crew gives the time as about 2:18 am Hong Kong time, which is 3:18 am Japan time (18:18 UTC). According to the Pentagon, the launch occurred at 3:17 am Japanese time (18:17 UTC), which would put the Cathay sighting shortly after the launch of the missile from a location near Pyongyang, North Korea.

Since the missile flew for more than 50 minutes, it would not have reentered until after 4 am Japanese time. Given the timing, it seems likely the crew might have seen the first stage burn out and separate from the rest of the missile. This would have happened a few minutes after launch, so is roughly consistent with the 3:18 time.

The New York Times posted a map that shows the track of flight CX893. It shows that the flight was over northern Japan at 6:18 pm UTC (Fig. 1) and the pilots would have had a good view of the launch. By the time reentry occurred around 7:11 pm UTC, the plane would have been over mid-Japan and reentry would have occurred somewhat behind them (Fig. 1).

Fig. 1. Maps showing the location of flight CX893 shortly after launch of North Korea’s missile near the red dot on the left map, and at the time of reentry of North Korea’s missile, which took place near the red dot on the right map. (Source: NYT with UCS addition)

Burnout of the first stage would have taken place at an altitude about 100 km higher than the plane, but at a lateral distance of some 1,600 km from the plane. As a result, it would have only been about 4 degrees above horizontal to their view—so it would not have appeared particularly high to them. Ignition of the second stage rocket engine and separation of the first stage may have looked like an explosion that caused the missile to fall apart.

There are also reports of two Korean pilots apparently seeing a “flash” about an hour after the missile’s launch, which would be consistent with the warhead heating up during reentry, since the missile flew for 53-54 minutes. Neither reported seeing an explosion, according to the stories.

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