Blast from the Past

In article ,
Pat Flannery wrote:
result in: http://www.wps.com/archives/wxvax7.e...ages/ktntb.gif
Note the railway tracks for scale, and the flying sparkling stuff- which
given that uranium is pyrophoric, I assume are the uranium pellets from
the reactor's fuel elements.

Nope. Kiwi's fuel, like that in most reactors, was uranium oxide, already
oxidized as far as it will go. Uranium metal melts at too low a
temperature for solid-core nuclear rockets.

Aren't these things supposed to melt down? This looks like an SRB
exploding.

The KIWI-TNT test was the result of really drastic measures to produce an
absolute-worst-case energy release, leading to massive overpressurization
of the casing (by vaporizing graphite!) and a "nuclear boiler explosion".

Previous tests had included things like loading a mock reactor onto a
rocket sled and slamming it into a concrete wall to find out how much its
core would compress in a worst-case pad accident, but prediction and
experiment disagreed annoyingly badly. So they wanted to find out what
would happen if things went bad in a way *well beyond* anything actually
plausible.

The normal drives for the control drums (Kiwi's equivalent of control
rods) rotated the drums at 45deg/s maximum. They were replaced by
pyrotechnic actuators that slammed them around at 4000deg/s in exact
synchronization. Total neutron yield was about 1/3 of that predicted,
total explosive yield equivalent to around 250lb of black powder (the
correct comparison -- the explosion was too slow to correspond to a high
explosive like TNT, despite the test's name).

I'll bet this was one fun clean-up job.

Not actually all that bad. Lots of isotopes, but almost all with very
short half-lives. Cleanup started about a week afterward, not to reduce
hazards (which were already small) but to analyze the explosion in detail.
They found essentially all of the casing and about half the total mass of
the fuel elements (the rest vaporized or burned).
--
No, the devil isn't in the details. | Henry Spencer
The devil is in the *assumptions*. |

In article , I wrote:
The KIWI-TNT test was the result of really drastic measures to produce an
absolute-worst-case energy release...

Addendum: anyone wanting to know more about either the technical history
or the political history of nuclear rockets needs a copy of James Dewar's
"To the end of the solar system -- the story of the nuclear rocket".
--
No, the devil isn't in the details. | Henry Spencer
The devil is in the *assumptions*. |

Henry Spencer wrote:

Addendum: anyone wanting to know more about either the technical history
or the political history of nuclear rockets needs a copy of James Dewar's
"To the end of the solar system -- the story of the nuclear rocket".

No kidding. It does a wonderful job of explaining how (and why!) the
1950's turned into the 1970's. Warning: It's not a pretty story.

--
Dave Michelson

On Fri, 19 Aug 2005 05:57:15 GMT, Dave Michelson
wrote:

Henry Spencer wrote:

Addendum: anyone wanting to know more about either the technical history
or the political history of nuclear rockets needs a copy of James Dewar's
"To the end of the solar system -- the story of the nuclear rocket".

No kidding. It does a wonderful job of explaining how (and why!) the
1950's turned into the 1970's. Warning: It's not a pretty story.

....How much actually gets blamed on the treehugging hippie radical
perverts, and how much gets blamed on Nixon and political bull****
games?

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

On Fri, 19 Aug 2005 00:38:50 GMT, (Henry Spencer)
wrote:

Previous tests had included things like loading a mock reactor onto a
rocket sled and slamming it into a concrete wall to find out how much its
core would compress in a worst-case pad accident, but prediction and
experiment disagreed annoyingly badly.

....Awww, don't leave us hanging on *that* one, Henry! What were the
values for each?

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

Henry Spencer wrote:



Addendum: anyone wanting to know more about either the technical history
or the political history of nuclear rockets needs a copy of James Dewar's
"To the end of the solar system -- the story of the nuclear rocket".


Since you obviously know all about this test* I've got some questions.
This report:
http://www.gwu.edu/~nsarchiv/radiati...b_l/br6l1k.txt
....states that LH2 wasn't used to fill the interior of the reactor
during the test- what was used instead?
(if it's in there, I didn't see it.)
Why do all the burning graphite particles seen flying from the explosion
seem to be of approximately the same size- is this related to how the
reactor's interior was constructed (i.e.- were the graphite/uranium fuel
elements a series of small units that are here being seen as they fly
burning out of the reactor fairly intact?)
Did the images of the interior of the reactor taken by the mirror
mounted over the exit nozzle during the test ever get released, or were
they classified to hide the exact physical configuration of the
reactor's interior?
Was the test itself classified at the time it occurred?

* Which didn't come as a surprise somehow. ;-)

Pat

In article ,
OM om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org wrote:
"To the end of the solar system -- the story of the nuclear rocket".
No kidding. It does a wonderful job of explaining how (and why!) the
1950's turned into the 1970's. Warning: It's not a pretty story.

...How much actually gets blamed on the treehugging hippie radical
perverts, and how much gets blamed on Nixon and political bull****
games?

The treehugging etc.'s didn't really figure into it. They were just
starting to be influential as the nuclear-rocket effort was already
winding down.

The political problems actually started under LBJ, or more precisely they
began to manifest themselves strongly under him.

Under JFK, it actually had been official Administration policy that the US
was committed to opening up the solar system (not just the Moon). Even
JFK was trying to backpedal on this toward the end, as the budget
implications began to show up; Webb had to keep reminding him that an
ambitious, ongoing program *was* official policy.

One of LBJ's earliest space-policy decisions was to postpone plans for a
nuclear-rocket flight test, pending a firm requirement for it. This
sounds minor, but in fact it was a major policy reversal: the ongoing
program *did* have a firm requirement for nuclear propulsion to enable
large-scale deep-space operations. Now everything beyond Apollo was
officially uncertain.

(LBJ was having to put together a federal budget for the first time, and
with an eye on the 1964 elections, he wanted to keep it below $100G.)

Ground technology work continued. The long-term future was less clear
than it had been, but there was still reason to hope. The axe really fell
in the budget debates of summer 1967, with the Congressional mood
noticeably altered by considerable turnover in the 1966 elections. NASA
lost almost all its long-term plans that summer; that was the year when
Slayton recruited a new batch of scientist-astronauts in spring, and then
when they reported for duty in fall, had to tell them that they would not
fly any time soon.

The summer 1968 budget hammered the point home. No, 1967 hadn't been a
temporary aberration. Webb reluctantly terminated long-lead funding for
further Saturn Vs. If memory serves, Dewar says that Webb's surprise
resignation that fall was the result of a final unsuccessful attempt to
convince LBJ to give post-Apollo space plans a higher budget priority.
Now there definitely wasn't a need for nuclear rockets.

The project survived a few years longer, but its political power base was
dwindling -- not least because its long-time champion, Senator Anderson,
was old and unwell -- and it finally died when one of Nixon's flunkies
decided that it was no longer worth the trouble. (Under LBJ, such
decisions were debated in front of the president; under Nixon, not only
was he not consulted, he wasn't even told afterward.) The cancellation of
the SST -- a project Nixon loved -- was, in part, Anderson's revenge.
--
No, the devil isn't in the details. | Henry Spencer
The devil is in the *assumptions*. |

(Henry Spencer) wrote:

The summer 1968 budget hammered the point home. No, 1967 hadn't been a
temporary aberration.

It's worth remembering that there was a near-catastrophic run on gold
in early 1968, with many of the good and great in global finance
worried about an imminent crash. It was the first lurch towards
Nixon's decision to go off gold in 1971. Wilbur Mills made it clear to
LBJ that guns + butter (butter including any space spending beyond the
Apollo already paid for, as well as expansion of Great Society
programs) was no longer an option.

Pop history remembers the Tet Offensive and New Hampshire primary as
driving LBJ's decision not to run again -- but I think the possibility
of being remembered as Herbert Hoover #2 rather than FDR #2 must have
concentrated his mind, too.

-Monte

On Sat, 20 Aug 2005 12:26:51 GMT, Monte Davis wrote:

(Henry Spencer) wrote:

The summer 1968 budget hammered the point home. No, 1967 hadn't been a
temporary aberration.

It's worth remembering that there was a near-catastrophic run on gold
in early 1968, with many of the good and great in global finance
worried about an imminent crash.

I wasn't too old at the time, so I'm only going by foggy memories here. Did that
run on gold have anything to do with De Gaulle's insistence that the US pay back
its supposed debt to France in gold?

It was the first lurch towardsNixon's decision to go off gold in 1971. Wilbur Mills
made it clear to LBJ that guns + butter (butter including any space spending beyond
the Apollo already paid for, as well as expansion of Great Society programs) was no
longer an option.

Once he got himself regularly serviced by a ho, did he mellow a bit? It sucks that
he ran Ways and Means...

Pop history remembers the Tet Offensive and New Hampshire primary as
driving LBJ's decision not to run again -- but I think the possibility
of being remembered as Herbert Hoover #2 rather than FDR #2 must have
concentrated his mind, too.

I think the unpopularity of the war weighed far more heavily on his mind than
the state of the economy. The economy didn't become a big issue until a
few years later. Nixon responded with his nearly wartime-like "phases" of
economic control. Ford opted for "WIN" (Whip Inflation Now) buttons. It was
a wash

Dale

In article ,
Pat Flannery wrote:
...states that LH2 wasn't used to fill the interior of the reactor
during the test- what was used instead?

Just air, I think -- might have been purge gas (probably helium) instead.
The test was deliberate gross abuse of the reactor to see what it would
do, so they wanted to stack the deck in every way possible.

Why do all the burning graphite particles seen flying from the explosion
seem to be of approximately the same size- is this related to how the
reactor's interior was constructed (i.e.- were the graphite/uranium fuel
elements a series of small units that are here being seen as they fly
burning out of the reactor fairly intact?)

No, there wasn't any fine structure like that in the construction, if I
recall correctly... but there may have been in the materials. I'd guess
that's the grain size of the graphite you're looking at.

Did the images of the interior of the reactor taken by the mirror
mounted over the exit nozzle during the test ever get released, or were
they classified to hide the exact physical configuration of the
reactor's interior?

No info -- haven't seen that level of detail.

Was the test itself classified at the time it occurred?

Not the fact of its existence or the broad outlines of what it was about.
Some of the technical details may have been classified for a while, ditto
detailed results -- quite a bit of leading-edge rocketry work was lightly
classified at the time, and the nuclear aspect would have encouraged that.
--
No, the devil isn't in the details. | Henry Spencer
The devil is in the *assumptions*. |