[ RadSafe ] Re: Fw: Someone just responded to your comment

[John Jacobus]

Don,
Read what I said.  I do not think about the LNT when I
make decisions.  I follow good work practices.  

I do not understand your first example, but if you
want an answer, I would not change the work practices
to save the dose.  Did you?

As for the second example, we do a lot of work with
P-32.  The $100 shielding can by you a lot of savings
as the shielding last about 15 years.

If you are looking for remote radiation detectors, try
a Primalert. 
http://www.elimpex.com/products/radiation-therapy/primerli.pdf
 It will save you dose and time.  

Sounds like you are thinking about ALARA and not LNT.

--- "Mercado, Don" <don.mercado at lmco.com> wrote:

> John Jacobus wrote: 
> 
> >Don,
> >I do not base my judgement on the LNT or what I
> think
> >about it.  I consider what is actions are need to
> get
> >the work done and keep down radiation exposures.
> 
> Then you DO think about LNT. You balance getting the
> necessity of
> getting the work done with the time/expense of
> keeping exposures down.
> If it extends the work time by 16 hours by changing
> the work procedure
> to reduce exposures by 100 mrem, would you do it or
> not? How about 3
> hours? One hour? Ten minutes? If you are a fan of
> LNT, yes, you do. If
> you are not, no you don't.
> 
> >I thought that is what ALARA is all about.
> 
> ALARA is a concept that allows HP professionals to
> use their judgment.
> It's the "R" in ALARA that we are talking about.
> What is "Reasonable"
> has a cost associated with it. What does $XXX buy
> you?
> 
> >If spending $100 for shielding, that is a good
> >investment as the material could be used again.
> 
> What are the associated costs of that "$100 for
> shielding"? Design time,
> ordering time, waiting for delivery time,
> installation costs and time,
> etc. That shielding costs more than $100. That $100
> really doesn't buy
> you much protection at all if that's all you are
> going to *really*
> spend. How much additional health/harm prevention
> does that $100 get
> you? Non-LNT fan: none. LNT fan: Nothing
> quantifiable. So what's the
> point in spending the money?
> 
> >If having a worker receive some radiation exposure
> in
> >completing a job, that is what their job is.  The
> >issue I think is whether or not anything can be
> done
> >to reduce exposure.  
> 
> The issue is whether it is "reasonable" to do
> something to reduce the
> exposure.
> 
> >By the way, on the first nuclear powered
> submarines,
> >e.g, USS Nautilus SSN-571, etc., there was a 20
> second stay-time for
> crew members as they went aft over >the reactor.
> There was no shielded
> tunnel over the reactor compartment. 
> 
> Spacecraft designers want to know how much radiation
> their parts are
> being exposed to when we x-ray them. Because of the
> circumstances, we
> can't use a shielded room. We have to x-ray them as
> installed on the
> spacecraft. To get the numbers the designers want, I
> start way back from
> the machine, stand in the primary beam and walk
> toward it with a survey
> instrument until I find the 100 mR/hr distance and
> then do inverse
> square calcs. Takes me all of about 2 minutes in the
> beam. Big deal.
> Doesn't even show up on my dosimeter. To test to see
> if interior room
> warning lights, emergency shut down switches, etc.
> work in a shielded
> room installation I go into the room, close the
> door, have the operator
> turn on the x-ray, confirm that it is running with
> my survey meter, and
> hit the switch, and confirm that it is shut down. 15
> seconds. Again, it
> doesn't even show up on my dosimeter. It is
> "reasonable" to have the
> operator set the machine to low kVp and mA to reduce
> exposure to me. It
> is not reasonable to install a remote operating
> system to test the shut
> down switches or a video camera to see if the light
> is working.  
> 
> >To tell you the truth, the only time I think about
> the
> >LNT is when I get messages from this list server. 
> Do
> >you think about the LNT a lot?
> 
> Yes I do. There's a situation at least once a week
> where I have to think
> of what is "reasonable". Being reasonable costs
> money. LNT is a big
> factor in costs of operations.
> 


+++++++++++++++++++
"Every now and then a man's mind is stretched by a new idea and never shrinks back to its original proportion." -- Oliver Wendell Holmes, Jr.

-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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