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DECISION
(on the appointment of examination)
May 18, 1959. city of Sverdlovsk The prosecutor criminalist of the Prosecutor's Office of the Sverdlovsk region Ivanov having examined the criminal case on the death of
students of the Ural Polytechnic Institute and taking into account that to determine the reasons for the death of tourists it is necessary
to make radiological studies and solve the issue of radioactive contamination of tourists' clothing, guided by Articles 63 and 171 of the Code of Criminal Procedure of the RSFSR ,
IT WAS RESOLVED:
to assign physical and technical expertise in the present case to resolve the following issues:
1. Is there a radioactive contamination of clothing and parts of corpses of dead tourists.
The expertise of the expertise is entrusted to the Chief Radiologist of Sverdlovsk Levashov.
At the disposal of the expert, to present all the clothes of Zolotarev, Dubinina, Kolevatova and Thibault Brignol, as well as part of their corpses.
Prosecutor criminalist
Junior Counselor of Justice (SIGNATURE) / Ivanov /
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Subscription
Given this subscription is that I am warned of the responsibility under articles 92 and 95 of the Criminal Code of the RSFSR
(Signature of Levashov)
18.V.1959g
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Reference!
In the examination report, all objects of investigation are numbered from No. 1 to No. 4
those:
No. 1 Kolevatov
No. 2 Zolotarev
No. 3 Thibault Brignoles
No. 4 of Dubinin
As in acts of autopsy
Ivanov
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Conclusion
Samples of solid biosubstrates and clothing, which were sent to the radiological laboratory of the Sverdlovskaya Gorshenepidstadt, were examined for the content of radioactive substances, and dosimetric measurements of clothes were carried out on the Tiss device, which revealed an overestimation of the natural background for 200-300 imp / min Further, with radiometric measurements without ashing in a lead cottage with cassette counters STS-6 in the number of 4 pieces, maximum contamination was established in some sections of deshdy:
1) a brown sweater from No. 4 -9900 rpm with 150 cm2.
2) the bottom of the bloomer from No. 1 - 5000 rasp / min with 150 cm2
3) belt of sweaters from No. 1 - 5600 rpm with 150 cm2
Table 2 shows the contamination of different types of clothing (see on the back).
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Table number 2
Contamination of clothes
Recalculation was carried out on the B-2 installation in a lead house with a cassette counter STS-6 in the number of 4 pieces.
Conversion factor of the installation B-2 k = 8,9
background in lead house (before flushing) 90 pulses / min
background in lead house (after washing) 100 pulses / min
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Experimental washing of clothes showed that the contamination is removed, the percentage of washing ranges from 30% to 60% (washing clothes was done in running cold water for 3 hours).
When determining the type of radiation, it is established that the activity takes place due to beta particles . Alpha particles and gamma quanta were not
detected.
The absence of appropriate instruments and conditions in the laboratory made it impossible to perform radiochemical and spectrometric analysis to determine the chemical structure of the emitter and its radiation energy.
Radiometric measurements of solid biosubstrates were carried out in a B-2 facility (No. 2554) in a lead house with a BFA-25 meter. The
unit was tested using a strontium preparation with the following activity:
1) 7,000 rpm
2) 2000 rpm
The results of sample measurements from No. 1,2,3,4 are summarized in Table No. 1 (see on the back)
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Table №1
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-
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Conversion factor of installation = 5,5
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The results of the measurements from the control samples are summarized in Table No. 3 (see below)
Table No. 3
Control samples
Control samples were obtained from the forensic medical expert of Dr. Renaissance. The samples of the tissues of a person who died in the accident of a
motor vehicle in the city of Sverdlovsk, also showed the presence of a natural radiological element of potassium-40 in approximately the same
amounts as in Table 1.
Thus, the results of the studies in Tables 1 and 3 do not exceed the averaged data on the content of radioactive substances in human organs and can be attributed to
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naturally-radioactive Potassium-40. Radiation by type refers to the Beta- particles; Alpha particles and gamma quanta were not detected.
CONCLUSIONS:
1) The solid biosubstrates studied contain radioactive substances within the natural content determined by
potassium-40.
2) The individual samples of clothing examined contain several inflated quantities of radioactive substances or radioactive
material, which is a beta emitter.
3) Detected radioactive substances or radioactive substances when washing clothing samples tend to flush, i.e. are caused not by a neutron flux and induced radioactivity, but by radioactive contamination with beta particles.
Chief radiologist of the city
27.V.1959 (Signed) / Levashov /
The investigations were carried out in the radiological laboratory from 18 / V-59 to 25 / V- (it is not visible on the scan, note).
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ADDITIONAL QUESTIONS TO EXPERTS:
1. Should there be (can it be) increased contamination of clothing with radioactive substances under normal conditions, i.e. without being in a radioactive contaminated environment or place?
Answer: It should not be perfect.
2. Was there any contamination of the objects you are researching?
Answer: As stated in the conclusion, contamination of radioactive substances / substance / beta emitters of selected samples of clothes of the samples sent is contaminated. For example, the notch from No. 4 - brown sweater at the time of the study had 9.900 decays of beta particles per minute at 150 cm2, and after washing / for 3 hours, we / he gave 5,200 decays per minute of beta- particles from 150 sq. cm.
For example, according to the sanitary rules in our country, the contamination in the beta particles from 150 square centimeters per minute should not exceed the purification / washing / 5.000 decays, and after cleaning / washing / there should be a natural background, e. as much as it gives cosmic radiation to all people and all objects in a given locality. This is the norm for workers with radioactive substances.
Cutting from No. 1 - the sweater belt shows up to a wash of 5.600 decays, and after washing - 2.700. The bottom of the bloomer from No. 1 shows 5,000 decays before washing and 2.600 after washing. In your data it is indicated that all these objects were in the flowing water for a long time before the study, i.e. have already been washed.
3. Is it possible to consider that this clothing is contaminated with radioactive dust?
Answer: Yes, clothes are contaminated or radioactive dust dropped from the atmosphere, or this garment has been exposed to contamination when working with radioactive substances, or on contact. This pollution exceeds, as I have already indicated, the norm for persons working with radioactive substances.
4. What do you think, what could be the degree of contamination of individual objects, if you take into account that prior to research they had been in the running water for about 15 days.
Answer: It can be assumed that the contamination of individual garments was many times greater, but here one must take into account that clothes could be washed unevenly, that is, with varying degrees of intensity.
Expert Levashov
Chief radiologist of the city of Levashov (Signed) 05/29/1959 (date on the unknown public of the scan from Bujanov's textual text - note)
Topic: Expert opinion (Radioactivity results and questioning) (Read 15922 times)