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Re: dave's answer to one of your questions





Again, this is hardly any secret. This scenario is analyzed in the NRC's

Response Technical Manual (RTM-96, Vol. 1, Rev 4; March 1996). Section D of

this document is Spent fuel Pool Damage and Consequence Assessment. One of

the accidents analyzed is a Zircaloy cladding fire.



The most conservative estimates of the dose at one mile are 30 rem TABD

(acute bone dose) and 80 rem thyroid (Fig. D-2 BWR/PWR spent fuel pool

release event tree for a Zircaloy fire in one 3-month-old batch of fuel).

It should be noted that for the events analyzed, the highest thyroid dose

at one mile is 100 rem (Fig. D-4 BWR/PWR spent fuel pool release event tree

for a gap release from 15 1-year-old batches of fuel).



Other info:



1-h ground level release, D stability, wind speed 4 mph, no rain.



TABD includes 1 h of inhalation, 1 h of cloudshine, and 24 h of groundshine

to an adult performing normal activities.



Thyroid dose includes 1 h of inhalation exposure to an adult



Code used: RASCAL 2.1





                                                                                                                            

                    Norman Cohen                                                                                            

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                    owner-radsafe@list.vand       Subject:     dave's answer to one of your questions                       

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                    11/19/01 05:06 PM                                                                                       

                    Please respond to                                                                                       

                    Norman Cohen                                                                                            

                                                                                                                            

                                                                                                                            











Dave Lochbaum wrote:



> Hello Norm:

>

> The NRC's report from October 2000 documented that a spent fuel pool with

a partial water draindown can lead to a

> spent fuel fire. The zirconium cladding (i.e., the metal tubes that

contain the fuel pellets)

> can reach its ignition temperature in the presence of air when there's

inadequate cooling. The resulting fire leads

> to loss of integrity of the metal tubes, allowing the radioactive

material inside the tubes to be

> released. The radioactive gases and small particles can escape the fuel

handling building and reach the atmosphere.

> Due to its decay, iodine-131 is not much of a concern in this scenario.

But cesium-137

> poses a concern due to its longer half-life (about 30 years as opposed to

8 days).

>

> Take care,

>

> Dave

>

> >>> Norman Cohen <ncohen12@home.com> 11/19/01 09:40AM >>>

> Dave,

> Can you explain furtrher your comments about the fuel catching fire and

> being dispersed into the atmosphere.

> Norm

>

> Don Mercado wrote:

>

> > http://www.pbs.org/newshour/bb/terrorism/july-dec01/nuclear_11-02.html

> >

> >







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