[ RadSafe ] Regarding Greenpeace calculation of doses fromFukushima

[Victor Anderson]

Good Evening,

I have reviewed the calculation.  It is poorly done and not accurate.
HOTSPOT is code designed to give quick approximations to several different
situations.  Fires, explosions, and general releases are among them.  The
code will also provide estimations on nuclear weapons effects.  HOTSPOT does
have the ability to "adjust" output to match measurements by changing source
term values, stability classes, wind, particle deposition and so forth.
Like all Gaussian model codes, HOTSPOT cannot truly predict airborne
radioactive materials concentrations, inhalation doses, deposition, and so
forth.

For starters, the author of the Greenpeace calculation does not truly state
the inputs to the HOTSPOT code.  What model was used? What about factors
such as damage ratio, airborne fraction, plume rise and so forth?  In the
setup page for HOTSPOT there are number of factors that must be selected
such complex or simple geometry, terrain, Dose Conversion Library, etc.  The
results of the Greenpeace calculation are given in effective dose.  HOTSPOT
provides dose results in TEDE using either FGR-11 or FGR-13 guidance.  For
deterministic effects, HOTSPOT provides results in units of either
rad-equivalent or Grey-equivalent.  HOTSPOT does not provide doses for
children.

I ran the problem using what little information is in the paper.  The
results do not match the Greenpeace results.  HOTSPOT yields a maximum TEDE
dose of about 2.5E-7 SV at about 3 km downwind for the 40 PBq release.  I
can run the other case, but frankly it is just not worth the time.

It appears the calculation is a politically motivated work designed to cast
doubt on the WHO calculation and give the reader a strong impression that
things were worse than reported.  The usual anti-nuclear propaganda.

Victor

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of John Ahlquist
Sent: Thursday, March 14, 2013 11:16 AM
To: Radsafe
Subject: Re: [ RadSafe ] Regarding Greenpeace calculation of doses
fromFukushima

In my day I found HotSpot to be very useful for an emergency situation.  You
got 
a quick estimate to guide your actions which is useful in case of a small 
accident, an explosion involving rad materials, etc.  It can provide a
useful 
and quick [several minutes] preliminary answer while NARAC is getting into 
action.  However the HotSpot link itself says

"The HotSpot atmospheric dispersion models are designed for near-surface 
releases, short-range (less than 10 km) dispersion, and short-term (less
than 24 
hours) release durations in unobstructed terrain and simple meteorological 
conditions. These models provide a fast and usually conservative means for 
estimation of the radiation effects associated with the atmospheric release
of 
radioactive materials."
It is not designed for long term releases from multiple sources over complex

terrain with complex meteorology.  It is not appropriate for what GreenPeace
was 
trying to do.  One would have to check their assumptions, too, because the 
results can be significantly influenced by input assumptions.  

John Ahlquist

Date: Wed, 13 Mar 2013 18:35:17 +0000
From: "Dixon, John E. (CDC/ONDIEH/NCEH)" <gyf7 at cdc.gov>
Subject: Re: [ RadSafe ] Regarding Greenpeace calculation of doses
    from    Fukushima
To: "'The International Radiation Protection (Health Physics) Mailing
    List'"    <radsafe at health.phys.iit.edu>
Message-ID:
    <443B252CFD74854783FFA866594EA93E24384AFF at EMBX-CHAM4.cdc.gov>
Content-Type: text/plain; charset="us-ascii"

The use of the HOTSPOT code would not be appropriate for estimation of doses

(aka, health effects) from the releases that occurred from the Fukushima 
reactors. The dispersion patterns were far to complex. For example, the wind

patterns were not in just one direction, but all directions (360 degrees) 
because Japan is an island.

I would also not give Greenpeace much credence on this subject.

I would consult NARAC directly and find out which models (LaGrange based)
they 
were asked to run for the kind of information which you seek.

Regards,
John E. Dixon, CHP

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu]
 On Behalf Of Victor Anderson
Sent: Tuesday, March 12, 2013 9:57 PM
To: Mattias.Lantz at physics.uu.se; 'The International Radiation Protection
(Health 
Physics) MailingList'
Subject: Re: [ RadSafe ] Regarding Greenpeace calculation of doses from 
Fukushima

Yes,

I have used it a lot.  What do you need to know?

Victor

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Lantzelot
Sent: Monday, March 11, 2013 7:22 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: [ RadSafe ] Regarding Greenpeace calculation of doses from
Fukushima

Is there anybody on the RADSAFE list that has experience with the use of the

Hotspot code? ( https://narac.llnl.gov/HotSpot/HotSpot.html)

As probably known to most of you Greenpeace grabs whatever media attention
they 
can get (succeeding remarkably well in some countries), claiming that the
recent 
WHO health effects study on Fukushima is covering up the true dose rates.
Once 
again they refer to "independent nuclear expert" Oda Becker, her report
after 
using Hotspot is here:
http://www.greenpeace.org/international/Global/international/briefings/nucle
ar/2013/2012_OdaBecker.pdf