Re: Japanese dose readings - for real?

[Brian Rees <brees@lanl.gov>]

Andy,  as usual, good points.  There is the potential to deliver 3.1 mSv IN
AN HOUR, neutron,  from a criticality at 2 km, the rub being that it's in
ms or even us (milli seconds or micro seconds).  Since it appears that the
assembly is pulsing (not unexpected), dose rates will rapidly peak, and
fall off as the solution heats, looses reactivity, shuts down, and fission
product decay predominates.  When the solution cools, it can reassemble and
burst again.  The 10x background at 2 km also sounds reasonable, that'd
work out to ~ 400 R/hr at 1m using 1/r2 thumb rule.  

It's hard to tell what they're using to measure levels, and that could fuzz
the real picture considerably,  time will tell...

(my own opinion)

Brian Rees
Los Alamos National Laboratory 
Los Alamos Critical Experiments Facility
Operational Health Physics
brees@lanl.gov


At 02:23 PM 9/30/99 -0500, you wrote:
>>As of late Thursday night, 3.1 millisievert
>>of neutrons per hour, or about 15,000
>>times the normal level of radiation, was
>>detected two kilometers (1.2 miles) from
>>the accident site,'' an Ibaraki Prefecture
>>official told Reuters. 
>
>----------------
>
>Does anybody know who measured this dose, if they were using appropriate
>instruments, if they were reading their instruments correctly, and if they
>knew what they were doing?  If we don't know these things then, in my
>opinion, this is just a rumor that may or may not reflect reality.  I would
>think that dose readings this high should be verified by competent personnel
>before they are accepted.
>
>Andy
>
>Andrew Karam, CHP              (716) 275-1473 (voice)
>Radiation Safety Officer          (716) 275-3781 (office)
>University of Rochester           (716) 256-0365 (fax)
>601 Elmwood Ave. Box HPH   Rochester, NY  14642
>
>Andrew_Karam@URMC.Rochester.edu
>http://Intranet.urmc.rochester.edu/RadiationSafety
>************************************************************************
>The RADSAFE Frequently Asked Questions list, archives and subscription
>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html