Dear list

The measurements of dust from a filter of an appartment block near the spot where the EL-AL Boeing has been crashed the measurements gave 0,0006 per cent uranium236.

http://www.web-light.nl/VISIE/du-gooioord2000.html

With regards--
Hans de Jonge
e-mail <hansdejonge@xs4all.nl>

url http://www.web-light.nl/VISIE/index1.html     (Nederlands)
url http://www.web-light.nl/VISIE/ud_main.html   (English)

Dear Mr. de Jonge,

Isotopic measurement of depleted uranium used in Iraq or in the El-Al plane by mass spectroscopy showed the abundance of U-234 = 0.0008, U-235 = 0.2015, U-236 = 0.003 and U-238 = 99.7947  atom per cent (measurements reported by Len Dietz). In quoting the abundance of U-236 = 0.0006 +/-, one standard deviation? is not given. If this measurement has been performed by a single sector mass spectrometer (like a multi-collector Finnigan MAT Mass spectrometer) at times has memory effects. I have encountered many measurements that show U-234 and U-236 abundances quoted with fair accuracy as indicated by the computer associated with the spectrometer, yet the measurements are not that accurate. In one set of measurements, the abundance of U-236  is given higher than 0.003 per cent in some specimens. You can see that pure DU mixed with natural uranium will give less than 0.003 per cent as abundance. You see, in natural uranium the abundance of U-236 is zero.

There are three types of DU with varying abundances of U-235. I recall that hangar dust tsken from the area where the remains of El-Al airplane were stored, had almost pure DU of the above isotopic composition. Perhaps, we can get a better idea if you let us have the isotopic abundances of all uranium isotopes with errors quoted as one sigma or 2 sigmas.

Hans, we have been trying to standardize methods for measuring DU content in specimens. There are a lot of difficulties in getting accurate measurements. One has to exercise great care at every step in the methodology.

Regards,
Hari Sharma

Dear Hari Sharma,

If the U-236 is really present in the balance weights of the EL-AL Boeing this can
be measured easily in the hangar dust with 13.2 ppm uranium. In 1998 as far as it
was concerned by me there was no awareness of measuring U-236, so I have not asked
Pat Horan to measure it.
I will send her a new sample from the hangar dust  to measure U-236.
I am also convinced the measurement should be accurate and careful. If the results
are there I will put it on the du-list.

With regards,

Hans de Jonge