From: yodaiken@chelm.cs.umass.edu (victor yodaiken)
Newsgroups: sci.energy
Subject: Re: Nuke Stupidity Rebuttal
Date: 27 Sep 92 19:55:35 GMT
Organization: University of Massachusetts, Amherst

In article <1992Sep26.070724.15965@nuchat.sccsi.com> kevin@nuchat.sccsi.com (Kevin Brown) writes:
>In article <53930@dime.cs.umass.edu> yodaiken@chelm.cs.umass.edu (victor yodaiken) writes:
>>In article <1992Sep24.205410.7405@nuchat.sccsi.com> kevin@nuchat.sccsi.com (Kevin Brown) writes:
>[...]
>>>While this may be true, I was under the impression that the only types
>>>of severe failure that would be of any concern at all involve breaches
>>>of containment.  I would think that this would simplify the problem
>>>space considerably.
>>
>>Not really, small failures can add up to big failures. For example,
>>suppose that a backup power system fails during a SCRAM, the loss
>>of a battery or the improper care of a diesel or the misinstallation
>>of lightning surge protectors .... could all impact on probabilities
>>of big failures.
>
>Okay.  Well, let's suppose that the things you're talking about happen.
>What sort of "big failure" are we talking here?
>
>My point is this:  I don't see how the kind of scenario you're so concerned
>with can occur without some kind of release of highly radioactive material
>from the reactor.  And as far as I know (this could be sheer ignorance on
>my part, of course), the only way such a release can occur is when the
>containment is breached.  After all, the *job* of the containment is to
>prevent such a release, yes?

Well, that's the big question isn't it? What if a TMI style
screwup happens at an older plant and when they finally start 
cooling it the reactor vessel splits open due to the loss of 
ductility associated with nuclear radiation, suppose that the
plant has a weaker containment dome than did TMI (which was 
especially strengthened due to the nearby airport), suppose that a
venting valve from containment is stuck open, or that there is a
lightening strike and the operators lose instrument power, or that
someone panics and opens a venting pipe or that the turbine cracks and
sends a large metal fragment through the containment wall  ...., suppose
its a BWR plant and the rods won't withdraw, and the cladding catches fire
or that a fuel barge tips over on the cooling water intake or  .... 

Is the probability of all this equivalent to the probability of a meteor
strike? If so, what's the evidence?

>>>Yes, we *do* pay more attention to accidents with terrible consequences
>>>than those with minor consequences.  I do not question that this is so.
>>>I question that this is wise.
>
>I wanted to reiterate this.
>
>We humans have a fascination with the spectacular or the unusual.  That
>we have a tendency to emphasize such things in no way indicates that we
>should base our decisions on those tendencies.  For some reason, however,
>you seem unable to keep yourself from doing just that, at least with
>respect to nuclear power.  Why is it that you seem inconsistent in this
>regard?  Why is it that your decisions with respect to transportation
>(to name one example) are not similarly based primarily on the spectacular?

We have to make decisions about what we think are credible scenarios and
what we think are worthwhile risks. 


>>>As for your car, what *I'm* saying is that you're probably better off
>>>using the reliability of your headlight system than the reliability of
>>>your brakes as the prime determining factor in the decision of what
>>>form of transportation to use (note, however, that *neither* is probably
>>>a good factor to use in the decision.  It's a relative thing).
>>
>>Did you learn to drive in Boston? 
>
>No.  I learned to drive in Houston.  Is there a significant difference?
>

Unfortunately no. Driving in either town is suicidal.

>By the way, I have experienced electrical system failure that took the
>headlights with it before.  The danger such a failure presents should not
>be underestimated.  It is quite possible that the danger is very close to
>the danger presented by a brake system failure.

Look, you have your risk aversion strategies and I have mine. We are
both given a choice of a broken down car to get from A to B. I
pick the car with working brakes, missing one headlight, and you pick the
car with both headlights and no brakes. I'll even give you a head start,
since I don't want to be anywhere near you on the road.

>
>>>Interesting stuff.  I would ask, then: what is the proper metric to use for
>>>deciding which risk model to use (note: there may not be a good or simple
>>>answer to this one, in which case references would be appreciated)?
>>
>>Look at the EPRI book previously referenced. Also see Brittle Power by
>>Lovins for another view of risk. 
>
>Okay.  These are views, though, correct?  Are they considered definitive?
>
>If not, then please direct me to something that *is* considered definitive
>(by the scientific community).  If no such thing exists, then I must
>conclude that there *is* no single proper metric to use.

The EPRI work reflects the mainstream of the scientific community, there is
no definitive work in this relatively new and contentious field.

>>>>deaths over 3 days embedded in 10 death free years.
>>>>I disagree. Who's being objective?
>>>
>>>Whether or not these are "equivalent" depends on how you're measuring them.
>>>In terms of the numbers alone, they are quite obviously equivalent.  Dead
>>>is dead, no matter how it's concentrated.
>>
>>Right, but we can easily tag on other numbers which expose the difference.
>>Suppose that there are 100 people living in my village and that we
>>chose between the risk of losing 20 people in one disaster and losing
>>20 people over 10 years. Clearly, the village itself may not be able to
>>survive a sudden loss of 1/5 of the population, but it may be able to
>>cope with a longer term loss. 
>
>Change the data the model has to work with, and you change the model.  What
>you've done above is provide additional information to work with.  So, with
>the additional information, I agree that the two cases (losing 20 people in
>one disaster, with no deaths during  the remaiing time and losing 20 people
>over a period of 10 years) are not equivalent.

So, expected deaths from fossil induced lung diseases cannot be directly
compared to expected deaths from a nuclear melt-down without some 
additional explanation.

>If you're trying to say that our decisions must account for the specific
>circumstances surrounding them, you'll get no argument from me.  However,
>the discussion of nuclear power versus coal power has thus far been one
>without such detail.  It has thus far been about the "general case".  As
>such, there is no such detail of the type you provide above, and as such
>the models will necessarily seem somewhat simplistic.

I have not been arguing that nuclear is worse than coal, I've been arguing
that simplistic justifications of nuclear will not fly.

>>The real world is very complex, and we cannot
>>hope to capture it all in any formula. 
>
>Ah, but this was not my intent.  Rather, my intent is to capture the basic
>essence of the real world, and to do so with as little reliance on my own
>value set as possible.

Of course your value set determines what, in this issue, you find to be
essential.

>>Your choice to value what your
>>model can calculate over the subjective, but real, phenonemna which your
>>model ignores, is not an objective choice.
>
>Come again?  You think it's not an objective decision to place less
>significance on that which you cannot determine objectively?

Yes, there is no objective reason to prefer what can be easily
quantified over what cannot be easily quantified. The importance of
real phenomena does not correlate well with the ease with which we can
construct mathematical models of them. 

>This may be.  Ultimately, the desire to attempt to model the real world as
>accurately as possible is a value judgement.  However, I would argue that
>at the very least it is a *useful* value judgement (which, one may argue,
>is in itself a subjective term).

We ask about the relative advantages of N vs. F. You capture some of the 
relative advantages via a formula which I suggest ignores some key
criteria. For you to insist on ignoring those criteria is not a sign of
objectivity.

>
>[on risk]
>>>>There is no analytical model which will allow us to make an unbiased and
>>>>objective judgement.
>>>
>>>THANK YOU.  You have put into words something that I have observed to be
>>>the case for quite some time.
>>>
>>>Since the danger ("risk") presented by each type of plant cannot be assessed
>>>in an unbiased and objective fashion, but the benefits and costs *can* be
>>>assessed in an objective and unbiased fashion (reasoning: we have large
>>>amounts of data on the amount of power produced by each type of plant, the
>>>operating expenses for each, the building costs for each, and the pollutants
>>>produced by each), and since the real world doesn't give a damn about how we
>>>feel about things, I argue that we would be better off, in real-world terms,
>>>making the decision *primarily* based on the objective cost/benefit
>>
>>Presumably, we make decisions in order to make ourselves happy, not
>>to maximize some arbitrary indicator. The "real world" may not give
>>a damn about how we feel, but  we do (or should). We invent 
>>mathematical models of the world to help us understand it, and to
>>help us understand the consequences of our decisions. We do not, or
>>should not, come to believe that these models should dictate our
>>decisions.
>
>
>Right.  But note that this doesn't contradict what I'm saying.
>
>That we care about our own happiness is precisely why we attempt to model
>the real world, just as you say.  The object is to control our own actions
>such that the feedback we receive from the real world maximizes our
>happiness.  The assumption is that the more accurate our models are, the
>closer we can get to this maximum (i.e., the happier we'll be).  Inasmuch
>as the models we use are basically our best guess about how the real world
>actually works, it seems obvious to me that if you care so much about our
>happiness, you'll rely on those models as the primary determining factor
>in your decisions (reasoning: the models predict real world behavior based
>on the decisions you make.  While no model is 100% accurate, most are
>better than chance.  Not using them is, I would argue, equivalent to relying
>on chance.  You might get lucky, but you probably won't).

This is not a correct assumption. As a simple example, suppose, that
I argue that the reliability of computer programs can be acertained
by dividing the number of lines of code by the number of variables. You
object, and argue that such subjective considerations as one's faith in 
the  diligence of the programmers and the novelty of the methods used are
critical indicators. Am I being more objective, more accurate, more
scientific than you are?

>Yes, it *is* the best we can do for many issues.  The problem is that, at
>least with respect to the issue of nuclear power, it *isn't* the best we
>can do.  In the case of nuclear power as an alternative to coal power, we
>have behavioral models and cost/benefit models which have real-world data
>to support them, and that means that, if we choose to base our decision on
>them, we can do better than chance in getting the results we want.  Basing
>our decision purely on subjective judgements, however, is effectively the
>same thing as relying on chance to make the decision.

Of course, even accepting your argument, we still have to decide which of the
conflicting cost/benefit analysis we wish to accept. 


-- 


yodaiken@chelm.cs.umass.edu