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August 13, 2008

Indian Point Worst Case Nuclear Accident Scenario is not Credible


There was a 2004 study that posited a worst case nuclear accident scenario. This is related to a previous analysis of the deaths per TWH from different energy sources.

It assumes super-terrorists making a successful attack on the Indian Point nuclear reactor with a plane and then assume that optimal weather and optimal everything else for maximum casualties.

I do not believe the starting point of the scenario. Successful hijacking of a plane post 9-11. Since 9-11 pilots do not come out of the cockpit no matter how many passengers or crew are killed. If you are worried about terrorists doing this then do not secure all of the rich targets in the USA or other places but kill terrorists like Al Qaeda which is being done. There have been no major terrorist operations of this scale and the public and the system are ready to resist this scenario. Also, a simple defense is to setup about 10-15 story poles with sparse cabling so that any jet would run into that and be destroyed before hitting any of the nuclear containment structures. The netting or cabling would be like somewhat larger versions of the netting over a golf driving range or baseball backstops.



The report considered an attack on the Biblis B PWR by a small jet (Airbus A320) or medium-sized jet (Airbus A300) travelling at speeds from 225 to 394 miles per hour, where the peak speed of 394 mph was determined through the use of simulators. GRS concluded that for an event in which the jet did not penetrate the containment, but the resulting vibrations caused a primary coolant leak, and the control room was destroyed by debris and fire (a condition similar to a station blackout), then control of the sequence of events would be “ uncertain.” Biblis B was designed for protection against the crash of a 1960s-era Starfighter jet and as a result is equipped, like most German reactors, with a double containment. In contrast, Indian Point 2 and 3, while of the same 1970s vintage as Biblis B, were not designed to be resistant to airplane crashes, and do not have double containments.



I do not believe the radiations deaths figures that are quoted or the resultant cancer deaths.

the $2 trillion is based on the 99.9 percentile case of a BS scenario. 95% was $1 trillion.

Nuclear plant security is adequate

Anti-Radiation drugs far (5000 times ) better than potassium iodide are being developed.

Spalling concrete with material going deeper into the floor concrete and the ground does not create the bad scenarios that are postulated.

Indian Point is safe.

Indian Point will stay open.

The full independent Indian Point safety report is here.

Pg 127-133 are the relevant part for the airplane strike scenario.

Visual inspection of the concrete for signs of cracking and spalling are required by the American Society of Mechanical Engineers (ASME) Section 11 IWL Code and are performed regularly. The structural integrity of the buildings and its leak tightness are regularly verified by testing. The buildings were pressurized to 54 pounds per square inch (psi) (115 percent of the accident rating) – Unit 2 was tested in March 1971 and Unit 3 in January 1975. Integrated leak rate tests are performed periodically to pressurize the containment buildings to 47 psig and measure total leakage. During these tests, the building expands several inches and the concrete is therefore expected to experience minor cracking due to the physical growth of the structure. Visual inspections are performed during and following the test to observe for unexpected cracking or spalling of the concrete. The last tests were performed on Unit 2 in 2006 and on Unit 3 in 2005 with no structural concerns identified.


Numerous tests and analyses by research organizations conclude that the large commercial aircraft and turbojet engines in use today would not penetrate a containment structure like that at IPEC, even on a direct hit at 350 mph. Structural integrity and leak tightness of the buildings would be maintained. Furthermore, the energy of impact would be absorbed by the structure, causing only minor movement, and would not dislodge or damage equipment on the interior of the building.

In order for terrorists to hijack and then succeed in crashing an aircraft into the IPEC facility, there would need to be a collective failure of all of the barriers – regulatory, procedural, institutional and societal – which stand in the way of such an event. These include:

- Multiple terrorists would have been able to avoid detection by federal, state
and local law enforcement agencies to plan a coordinated attack, to acquire
the weapons they need to take over the aircraft, and to penetrate airport
security.
- The terrorists would have to successfully wrest control of the aircraft from
its crew and successfully resist the opposition of one or more sky marshals,
if aboard, and of perhaps 100 determined passengers. (Evidence from
United Flight 93, the apprehension of shoe‐bomber Richard Reid, and the
widespread recognition that the pre‐ 9/11 tactic of passive acceptance by
airline passengers of hostile acts in the air strongly suggests that this is
unlikely.)
- Federal Aviation Administration (FAA) Air Traffic Controllers, who
continually monitor the adherence of aircraft to authorized flight patterns,
would have to have been ineffective in detecting the airspace violation and
mobilizing the interdiction capabilities now in place.
- The terrorist hijackers would then have to successfully maneuver and
control their large aircraft near the ground at a high rate of speed, in the
difficult terrain surrounding IPEC, and score a direct hit on a target (an IPEC
reactor containment or fuel pool) that is tiny by comparison with the World
Trade Center. This would be an extraordinary feat of airmanship.

The walls of the IPEC containment buildings are constructed of reinforced
concrete of thicknesses varying from 3½ to 4½ feet. This concrete is
reinforced with layers of large (most are 2¼ inches in diameter) welded
steel bars. The critical areas of the containment building are located at the
lowest level of the building where the concrete walls are the thickest. The
wall surfaces are all curved, adding substantial strength in comparison to
flat surfaces. The buildings are completely lined, on their interior surfaces,
with welded steel sheets. They are airtight and leak resistant, and are
regularly inspected and pressure tested.

Given structural design and configuration of the IPEC containment buildings and fuel
storage facilities, the redundancy and separation of accident mitigation systems, the
design and redundancy in fire protection, the capability of on‐site firefighting and
emergency response, and the availability of off‐site support systems, the Panel concludes that the probability of a large aircraft part striking the buildings with nuclear fuel inside and causing a significant release of radioactivity is extremely low, to the point of being non‐credible.

5 comments:

22a-rbZD.007 said...

First off, a word needs to be said about human capabilities.
There are definite limitations to what people can accomplish, even terrorists.
The failed World Trade Center bombing in 1993 proved this. If it is
possible to admire those engaged in evil, however, we must admire the
determination of the perpetrators, and the flash of inspiration they had,
that airliners were easy to take,
and that airliners could do what a bomb could not.

In a twisted, sickening way, that was their "greatest moment",
when they used what to us was a happy thing, a convenience we use to go on vacation,
and for business travel, as an instrument of Jihad.
When we look at the other "accomplishments" of such people, nowhere do
we see a level of success, a level of killing, even close to the 9-11 total.

You see, without the airliners, these people are only 1/100 as capable.

Yes, they might take a cruise liner, because ships have not been hardened
like our planes have, (and I truly hope they do not), but in any other
situation, terrorist actions, although apalling,
do not , can not ,rise to the level of an act of nature,
like a hurricane, or a flood.


When left vague, as a general proposition, terrorist threats, especially
terrorist threats to Indian Point, can assume any proportion in one's mind.
It is not only possible, but very easy to imagine some unspecified attack,
whose aftermath is a huge cloud of toxic material raining down on our
beloved Hudson Valley.

This would be unnacceptable in the extreme, the sum of all fears.
However, when studied one by one, in detail, each proposed terror attack
fails to rise to the level required to create the imagined scenario above.

The limiting factors come from two sources.
One source is the human real-world limitations of the attackers.
(not being gods, they have limited choices)
The second source, is from the almost unintentional "Over-Design"
of Indian Point, as it exists, today.

The regulators at NRC, being somewhat familiar with the 2 limitations
above, can appear rather smug, amazingly unruffled, and maddeningly
unresponsive to those who are NOT casually familiar with the limitations.
It is a culture split, between confident insiders, and worried outsiders,
and they are delinquent for not proactively bridging the divide.
They are not accustomed to such questioning, so prefer to not answer.


NEI is a nuclear industry group, a reputable, credible industry group.
They commissioned a Finite Element Analysis to be run on the containment
structures of Nuclear plants, when impacted by a fully loaded 767 plane.
Four Engineering firms at the top of the engineering industry were
actually tasked with the analysis.(this was not a gathering of papers, like some of the "analyses" run by activist groups, who draw conclusions on a large scale from
generally available information - see appendix "A")
In a Finite Element Analysis, accepted Strength of Materials values
are used as a starting point. These values, the hardness of 3000 pound concrete,
the shear value of 304 stainless steel, etc, are known, peer checked,
and cannot be forged, misused, or faked.
The analysis uses very accurate computer modeling to subject the
materials to stress forces, until they break, or until the force is dissipated.
Every bridge, every tunnel, every structure built today uses these same algorithms,
so their accuracy is long proven, many times over.
The unfortunate misuse of this math, to allow the MINIMUM material
to be used in the World Trade Center, is a dirty little secret of the
Civil Engineering world, and contributed to the 2600 unfortunate
deaths in NY on 9/11/01. HOWEVER... the opposite use of the math
was used in designing the containment. It was vastly over-designed.

NEI's contractors' computer runs demonstrated that, with the materials
used in airplane construction directly stressing the materials used in
dome construction, the airplane was destroyed, and the dome was left intact.
There was no collusion, there was no room for "fudging", the reputations
of non-nuclear Civil Engineering firms with no stake in Indian Point
were on the line, most of their business comes from elsewhere other than NEI,
and the analysis proved that the airplane scenario failed against
Indian Point's dome. This leaves the dome intact, not falling down,
with no killing cloud raining down on the Hudson.

This is the best judgement our society knows how to make,
concerning an airliner attack on Indian Point.

With the airliner denied to them, our imagined terrorists must now use
some other method to create the toxic cloud above the Hudson, and
each of these methods is only 1/100 as effective , as we said before.
(let us assume a captured ocean liner has no place in this discussion).

Let us use a truck bomb, as in Oklahoma City.
Mr. Macveigh's truck was parked at the sidewalk, at the front entrance
of the MacMurrah building. It collapsed the lower front side of the building,
but the upper front side and the back side were left intact,
as were buildings across the street. Explosive force dissipates mathematically
as the square of the distance from the blast, which means it tapers off
VERY RAPIDLY with even small increases in distance.

The possible avenues of approach to Indian Point for any truck ,
are so constrained, that the truck scenario is denied to terrorists.
Trucks are diverted, at the entrance, to a secure inspection area
half a mile from the dome, and over the breast of a hill, or berm,
and inspected in detail, with mirrors & sniffing equipment.
If such a truck did explode, the hillside would divert the blast upward
harmlessly into midair. The Square-of-distance physics must be kept in mind,
for at all possible approaches to the dome,
any truck blast would be reduced by a factor of 100,000, or 1,000,000.
Barriers, fences, and other impediments I am not at liberty to discuss
completely prevent any approach by a truck, even a series of trucks,
with each one blowing up the next barrier in turn.
Even inspected trucks are kept far way from vital equipment,
so deception by a familiar trucker would not gain any advantage.
Suffice it to say, your truck bomb has been considered, and mitigated.



We must therefore move on to a small plane, laden with explosives
for our next detailed consideration. Unfortunately, some physics
must be brought into the discussion here. The World Trade Center
was rectangular, which meant as each plane hit at dead center,
the impacted steel was rotated inward and sheared off, having
no masonry capsule to buffer or dissipate the pushing force
of the quickly evaporating plane. This is known as an orthogonal
torsion force, or "moment", and is the strongest force in play
in overturning buildings.
With the dome, these forces cannot arise. Here is why.
The dome, being circular, is an arch in 3 dimensions.
This means that a hit , even at dead center, does not produce
the torsion moment, but instead is resolved into a compression force
dissipating outward in all directions along reinforcing steel
which presents its END to the impact, not its SIDE, as in WTC.
Moreover, the dome steel is totally encapsulated in 3000 pound concrete,
as WTC's steel was not. This inertial buffering reduces pushing forces
before they ever reach the steel. WTC was denied this protection.
The concrete also is a highly efficient thermal barrier, preventing
fire damage to the steel. This is not a spray-on barrier as in WTC.
This is a heavy totally encasing block, around the steel, 4 feet thick.

Now consider the wrecking crews who topple buildings with dynamite.
They have found that naked explosives will not break columns.
Naked explosive blows itself OFF of the target, so the wreckers
have devised sturdy clamp-on devices to hold the explosive tight
against the column, shaping the charge inward, cutting the steel.
Without the shaping, nothing happens but a fireworks display.
With a small plane hitting the dome, even at dead center,
its explosives would not be "held" against the target, and would
simply blow outwards,in an innefective fireworks display.
What forces did arise, would be absorbed by the circular
concrete-encased dome steel, causing a rocking motion,
but no damage.

Now let us consider an airliner hitting the spent fuel pool.
Because of surrounding structures, and geography,
An airliner physically cannot fly the angled vectors
required to hit the spent fuel pool. The plane would
break apart in midair in trying.

Let us then consider a small plane flying into the spent fuel pool.
First, the fuel pool cannot be seen from the air. It hides very
neatly among other structures, and is protected from a straight-on
flight path. Therefore any pilot would require two things to fly
a small plane into this target. 1) exceptional piloting skills,
not attainable by the likes of Mohammed Atta, and
2) detailed insider information as to just where an overhead exposure
existed on the fuel pool (if any).
But..let us concede both these advantages. Water is the most resilient
impact barrier known, and is used to stop bullets in ballistic tests,
and to stop rocket sleds in NASA tests. The fuel pool is SOLID WATER,
encased in stainless steel, encased in concrete, buried in earth.
Any impact forces would hit the solid mass of the fuel pool
and dissipate harmlessly. Yes, the roof of the fuel pool could be damaged.
No, the amount of explosive fitting in a small plane could not
dissipate all the water in the pool, or even a significant portion of it.
Remember, this is AFTER we concede unlikely flying skills,
and unlikely precise information. Any water lost would be easily
and quickly pumped back in, by any one of a dozen means, (see Appendix "C")
even down to a firehose from the Hudson River.
Remember, no hot steam, or live processes are present at the fuel pool,
so just hitting it really does nothing at all, except destroy the plane.
Hitting it is impossible, or very nearly so.

Let us consider Mr Foster Zeh's scenario, of an intruder carrying a satchel
charge across all our fences, past all our guards, to the spent fuel pool.
A human can carry, at most about 150 pounds.
We see our special forces soldiers bowed down under 150 pound packs,
Just barely walking.
They do not climb barbed wire fences with these packs on.
Let us halve it, to 75 pounds. At 75 pounds, it is still hard to walk,
next to impossible to run, and a 75 pound pack carrier still will not
climb a fence, cut ribbon wire, and evade Foster Zeh's bullets at the same time.
Let us cut it again, to 30 pounds. Maybe this man can run & climb.
Can he run and climb four, or six, successive 12 foot high
fences topped with ribbon wire? Let us use a tag-team of terrorists,
each one sacrificing himself by blowing up himself & his 30 pound pack
just to make a hole in the outer fence, which the next team can use.
Ah, but there's a rub. Because they have to use the hole,
the whereabouts of the next team are exactly pinpointed,
and they are easily shot. Let us not forget that Indian Point has in place
detection schemes, video, electronic, & otherwise,
alerting a central CAS team of any approach to our fences, from inside or outside,
and hardened watchtowers with armed guards, as well as bulletproof
shooting stations at undisclosed locations both near the fences and at other
locations, setting up “killing fields” of crossfire.
But let us again give a miraculous boost to our terrorist,
and parachute him in, with his 30 pound pack, already inside all fences.
The interior of the Indian Point campus is now subdivided in to a byzantine
arrangement of man traps & cul-de-sacs, where a parachuter would set off
motion detectors by his presence, and by trying to move from compartment
to compartment. The relay tag-team method can't work here, so each parachutist
has to climb his own fence to get out of his trap. He will have to choose
one target for his explosion, and if he doesnt have an engineer's knowlege
coupled with an olympic parachute champion's abilities,
he cannot do real harm. (see Appendix "B")
MacVeigh's truck bomb weighed 10,000 pounds, this intruder carries 30 pounds.
He can cause distress, he can shut down the plant, but he cannot release
the toxic cloud blanketing the region for miles, which is your biggest fear,
and which prompted James Lee Witt's team to use the phrase:
“Could not protect the public from a fast breaking massive release”

Let us couple the parachutist with an insider, and allow them to enter the
control room, where they capture the controls, or blow them up.
The process plant at Indian Point can be controlled from a second system of
"Alternate Safe Shutdown" control rooms, sprinkled throughout the mechanical
areas of the plant. Therefore the controls at the control room are not essential
to shutting the plant down, and their capture, although troubling,
would not lead to disaster.
Operators in the alternate shut down rooms would simply shut the plant.



I know that if you have perservered to this point, you are now fatigued,
a bit overloaded with detail, and it is just this fatigue, this overload,
which I contend is what makes the vision of a huge toxic release over the Hudson
seem possible.

Who but the most technical, the most priveleged insider ,would know of
all the mitigations in place, making any release impossible, even a
terrorist-caused release?

This is what NRC knows, this is what makes their attitude seem retrograde.
It is not dereliction of duty that causes their silence,
it is the doing of their duty, their duty to not publicize security information.
To ask for all this to be discussed in public is perhaps unwise,
would you not say, seeing as most of the radioactivity
and ALL of the radioactive substances will remain in a shut-down Indian Point.

The reason FEMA and NRC think a massive release is already mitigated
is that a vigilant cadre of dedicated people man all the mitigations in
a running , online Indian Point. Only in the case of a shut-down Indian Point
does the Massive Quick Release Scenario touted by Mr. Witt become possible,
as those mitigating it move on to other plants leaving only an untrustworthy
Wackenhut type crew behind.

It is at this point that the sum of all your fears becomes a feasible reality.
Therefore my information for you today is this:

In pushing for the close of Indian Point,
you are enabling the worst case scenario,
making the evacuation plan useless.

With Indian Point running,
the worst case is prevented,
and the plan is adequate.





The few scenarios presented do not Exhaust the subject, but a longer letter would certainly exhaust any reader, So I have added Appendices “A”, “B”, & “C”, attached below, to Somewhat amplify what was said above, should you care to dig deeper.




Appendix "A":
Why slanting of results is impossible from a Finite Element Analysis.

The "analysis" as run by NEI’s four contractors, was not a call for an opinion.
Nor was it a call for a position paper.

Anti Nuclear activist groups like NCI have done dozens of so-called "analyses"
which really amounted to a reshuffling of some already published facts and
figures,with an activist agenda as their motive, and a "spin" built in,
so it is no surprise when these rather sloppy recompilations of prior work
give the results desired. They are mainly verbal exercises,
subject to interpretation at every stage,
and therefore can be easily misused.

Do not let anyone mislead you that Finite Element Analysis suffers from any
interpretive pitfalls as do NCI's position papers.

FEA is set in stone.

The computers and the computer programs used in FEA exercises are
preloaded, in the very program code, far below user level,
with the correct constants for steel hardness, accelleration of gravity,
coefficients of friction, bending moduli ,tensile strengths, shear points,
and a dozen other physical realities which are not reprogrammable,
because these factors never change in the real world.

When someone says "Oh, NEI just faked the results"
they are speaking from a mindset of political report writing,
or soft sciences like Social Science,
where constants and results may vary, and so may be faked.

Neither NEI nor its contractors created the FEA programs.

These programs are standard fare, provided to Engineering Firms
by a small group of programming firms specializing in this craft.

For NEI's contractors to have come up with a slanted,
or a false favorable result, would have meant
that they must have searched out the original programmers,
asked that a new,temporary (illegal) version of the FEA software be crafted,
allowing wrong equations to be used,or wrong constants,
then they must have run the new dishonest software
just long enough to get favorable results,
and must have then reprogrammed their computers with honest code
immediately afterwards,
to ensure that they could carry on Civil Engineering contract work for other clients,
who do not desire false favorable results,and who would suffer criminal penalties
were their structures to be found to be wrongly designed.
It is ludicrous to suggest that the program creators,if they could be reached,
would have any inclination to participate in such a crime,
since 99.9% of their business is non-nuclear.
It is also ludicrous to think that such a faked set of software
could be created,seeing as the software itself was actually accumulated over decades,
from established Civil Engineering practice.
No alternate, dishonest "devil's" Civil Engineering background exists
from which to craft these supposed skewed equations,so the evil genius
who could make them up, from scratch, for NEI, would have had to be an
Einstein and a Mephistopheles rolled into one super intellect.
This person does not exist, the programs are un-fakable,
the Engineering firms would have had no means to obtain
any results other than the true scientific result obtained.


Any person who chooses to suspect such results is beyond reach,
in a space where anything could be true, outside of science,
outside of this universe,
in a region of paranoia and desire so great, as to destroy honesty,
humanity, and good sense. This is the world of Witchcraft. I beg you,
do not subject the residents of the Hudson Valley
to public policy based on Witchcraft.

If we accept that the best analysis preserves the dome,
then Mr. Witt's Massive Rapid Release recedes into the realm of conjecture.
This both corroborates and explains Richard Meserve’s contention
That terrorist attack is contained within the envelope of existing mitigations.
Only an empty plant, a shut-down plant, is vulnerable
In the way which permits the worst case to occur.

But more is to be said about the dome--see Appendix "B"



Appendix "B"
Why the dome is not the main mitigation

The relation between the DOME, the PROCESS, & the CORE, is a very technical
subject, and because it takes some effort to learn, activists have granted themselves
the license to mix up the realities until the most frightening scenario was produced.
They have made it appear that things could happen, which cannot happen.

These mixed, erronious references were taken at face value by the Witt group,
thus creating the conundrum you and FEMA face today.

In normal operation, IPEC workers often enter the dome while under power.
You see,the dome is NOT filled with a soup of radiation, straining to get out.
The dome is, in fact, filled with very clean air,
a little warmer than outside air, and that is the end of it.
If Entergy decided to have a demonstration, where a 60 foot temporary hole
was made in the dome, no discernable change would happen,
and no radiation would come out.
We see immediately that all scenarios involving the smaller terrorist
Capabilities (less than an airliner) are now denied the ability
to produce the worst case toxic cloud raining down on the Hudson.
(for fuel pool, see Appendix "C")
Hurting the dome would shut down the plant, but that is all.

Deep within the dome, inside other concrete structures the size of buildings,
is the PROCESS.
The process is a set of pipes holding hot water. To let the process
out into the atmosphere, a terrorist would not only have to breach the dome,
he would then have to climb through the hole he just made, let himself down
inside by ropes, and start to search for a vulnerable, visible, unprotected
spot on the process, where he could place his 30 pound charge. Spots
where the process is naked, visible, and unprotected are very few, and
I myself have spent hours searching inside the dome, blueprint in hand,
unable to discern the process pipe I am to work on. The area inside the dome
is not an open maze of pipes as one sees in an oil refinery. When building our
process, the designers placed concrete missile shields (huge thick walls)
throughout the entire dome, to keep a break in one pipe from shooting
a debris chunk or "missile" into a second pipe. The process is embedded,
well hidden, and well protected inside the dome.

Now as to what can not come out from the process.
The process is just hot water. It contains no uranium, no cesium,
no plutonium, no americium, it is simple hot water, that is all.
The worst case massive cloud of toxic material cannot emerge from the process.
For that, one must expose the CORE.

The CORE is buried in a 12ft thick reinforced concrete pad in the Reactor Pit,
inside a 6 inch thick steel vessel, deep behind multiple structures,
and would require any attacker to use a series of "bunker-buster" bombs,
one after the other, in order to remove successively the dome,
the crane wall, the rod shield, the missile shields, the reactor pit,
and the reactor vessel in order to expose the core, as in Chernobyl.

In the 1991 Gulf War, American planes were sent, with all our best
technology, to destroy an Iraqi nuclear installation similar to,
but less hardened than our core.
It took many American warplanes, in multiple sorties over a period
of three days to finally destroy this installation.
(radiation was released on day #3, but did minimum harm).
This is the level of capability required, in order to finally produce
James Lee Witt's "Massive Quick Release" of radiation.

As far as I know, no group, agency, or nation has the wherewithall to
place successive waves of warplanes with "Smart Bombs" over
the Hudson River, and keep them there three days,
as was required in Iraq in 1991.

Appendix "C"
A Fuel Pool Fire Cannot Occur Unless IP is Closed

Before the Unit 2 R15 outage in 2002, our reactor engineers asked
that an additional safety margin be added to our Unit 2 fuel pool
during refueling operations. They wanted a "very cool pool".
One IPEC's senior Engineers spearheaded this effort, and a second, temporary additional
source of cooling water was provided by the simple expedient of
pipes & fire hoses pumping extra water from another source into the pool.
It was easy. In this same way, whatever mythical terror action
is applied to the pool, removing water, or stopping normal water
can be mitigated in very simple fashion, in ways we have already
used, with equipment which is still onsite, by the same crew who
set it up in 2002.

The many dire scenarios regarding our spent fuel pool only
take on a fearful aspect were they to happen WITHOUT
That engineer and his crew around,
that is to say, in a closed Indian Point.

If the plant is closed, without a full crew, and terror occurs,
Perhaps Foster Zeh and Wackenhut could improvise something,
but I trust Mr. Curry infinitely more.

22a-rbZD.007 said...

The usage of the worst case, as a limiting outer boundary, is a disused calculational technique, which became obsolete along with the sliderule. Sliderules computed only 3 significant figures, and so a case by vase iterative comparison, changing initial conditions for each run, was not feasible.( as it is today, digitally).

Where numerical iterations could not go, crude dimensional analysis was used as a stopgap.

Thus the wost case became marginally useful.

Here is the usage:

All other factors are frozen, or postulated as removed from the scenario, to provide a fictional clear field upon which to dimensionally estimate the worst case.

Therefore, it is postulated that all humans who could mitigate an accident are not present.
It is postulated that all physical mitigations are also removed. This includes containment buildings, missile shields, equipment hatches, automated spray or shutdown machinery, control rods, makeup coolant water, and the reactor vessel itself.

Thus the worst case scenario, is by definition "not credible".

The worst case run begins with an unshielded, unmoderated source term lying in the open air, with no surrounding vessel, no cooling water, no containment, and allows it to heat via its own internal reactivity , until it vaporizes freely into the open air, spreading on the prevailing wind currents. It is postulated that no one intervenes in any way, so that the reaction continues until spent, however long that might be.

The resultant circle of impact is then said to be the bounding outer limit of any more detailed calculations, which are then embarked upon on a long term basis, to derive the expected, or credible set of results.

To use the Worst Case, without the detailed iterated followup would be a metericious half use of the method. The worst case gives no credible result, but merely limits the outer boundary of the followup (realistic) calculational iterations.With today's digital iterative runs available, no current researcher would use the method.

Edwin Lyman , however, did just that, resurrecting half of the worst case method, 40 years after it had been declared not credible, and 30 years after NRC warned against its further use.He omitted the back half, where realistic calculated results are compiled, and did just the worst case, presenting it to the world as a "scientific result"

This is deception and scientific chicanery of the first order.

Lyman deserves jail time for what he perpetrated.

He created false advertising, for an advocacy group, and allowed the public to misapprehend it as "science".

Cyril R said...

Of course the terrorists won't use a soft shell against a hard target. They'd use armor penetrating home made stuff. Like a sabot plane - a (hyjacked)carrier plane with something heavy and solid as cargo. Say, a large number of heavy construction beams. Easy to get (not suspicious), and huge penetrating power.

A quick back on the envelope kinetics calculation tells me this would penetrate any known nuclear containment building and core. I'll grant you though, it's tricky with such a relatively small target.

Icreasing the containment wall's thickness by a large multiple would solve this, but would be very costly.

bw said...

It would be very suspicious to load a plane with girders. No one flies steel girders in planes.

Offense can always be increased to a level beyond a defense or around a defense. German Army versus Maginot line. Allied forces vs the Atlantic wall. Etc... or bullets vs bullet proof vests. Increasing caliber. You have a hand off to killing the terrorists who would try such actions. Intelligence agencies to identify them.

Notice that since 2001 the US has not had a foreign attack on US soil. Fighting them over there in Afghanistan or attracting them to Iraq has some benefit. The terrorists are not some fictional or hypothetical super-beings. They are real people and a finite number.

A few million nazis killed and now Germany is a productive and peaceful place. Japan had kamakazi pilots and fervent warriors. Japan is now a peace loving country. Decisive military victories with a good post war plan can work.

There just needs to be a proper mix of defense against threats and active elimination of threats. the US has tens of thousands of very important targets. Making each of them into a manmade Cheyenne mountain would make no sense. At a certain point you have driven the chances of a particular scenario too low and the higher risk becomes infiltration and sabotage or something else.

Cyril R said...

I agree that a carrier plane full of steel girders is unlikely, but not impossible either. They could use other solid heavy objects, not steel girders per se.

For example, tungsten heavy objects (cylinders, rods, girders, or other) would be perfect. Other heavy machinery or loads are sometimes hauled by plane, the terrorists might use anything they can get their hands on, anything heavy solid, robust and BIG would do. Now, that requires a lot of information and intelligence on the terrorists' side. But, intelligence agencies cannot guarantee full control of all airplanes. Really.

One solution would be to build nuclear plants underground.