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[First page is blank except for the following notation:]

"IX.1"

Applications of

Nuclear Physics

Atomic Energy Agency

Al-Qa'qa' Facility

Muthanna Facility

Table of Contents

1. Introduction and Conclusions
2. Biological Effects of Ionised Radiation
3. Mathematical Estimations
4. Radioactive Effectiveness of the Charge
5. Scientific Field Experiments

A. First Experiment
B. Second Experiment
C. Third Experiment

Attachments:

1. Attachment nr. 1: Details of the radiation experiment and preparation of the charge
2. Attachment nr. 2: Methods and mathematical calculations
3. Attachment nr. 3: Second field experiment
4. Attachment nr. 4: Third field experiment
5. Attachment nr. 5:Specifications of the Qa'qa 28bomb
6. Attachment nr. 6: Neutron calculations of the radiation
7. Attachment nr. 7: Opinion of the Air Force Command

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TOP SECRET

Introduction and Conclusions: The purpose of this report is to study the possibility of using the vertical channels of the Tammuz reactor to irradiate quantities of the raw materials of zirconium (containing zirconium, hafnium, uranium, and iron in different proportions) --Attachment nr. 1-- to be used as charges [of target material] in aerial bombs weighing approximately 1,000 KG each to give known weapons additional effectiveness by contaminating the areas in which these bombs are used through spreading radioactive material in a wide pattern in the air.

In order to define this effect and estimate the benefit of using it, a number of experiments were performed and theoretical calculations were made — Attachment nr. 2 . In addition, the necessary industrial facilities were established, with complete cooperation between the Atomic Energy Agency and the Al-Qa'qa' and Al-Muthanna Facilities of the Military Industrial Commission.

We paid special attention to safety considerations and to safeguarding the reactor, since the operations diverged from traditional methods, and we took precautions against the dangers of radiation to the people who handle the charge after it is irradiated and until it is dropped on the enemy.

Theoretical calculations show that it is possible to irradiate a charge containing 2.4 KG of zirconium in some of the vertical columns in the reactor so that the charge will have a biological effect during an irradiation period ranging from 7 to 15 hours. After that, this quantity of zirconium was actually irradiated. An attempt was made to manufacture a charge weighing 3 KG. Upon success, the irradiated material will be greater by the same amount as when decision is made to make use of all the vertical channels in the reactor. There are between 15 and 17 and the number can be expanded up to 20 since some changes need to be made to the reactor reservoir. It was confirmed through the experiment that the Al-Qa'qa' facility can produce charges with the exact specifications, and the charges can be put into the reactor channels without any great effect on the reactor itself.

Lead containers were designed to transport the charge so there would be no ill effect on the workers manufacturing the bomb during the during the assembly operation or on the team entrusted with carrying and releasing it. The lead container (with the irradiated zirconium charge inside it) was placed inside the bomb surrounded on all sides by high-explosive material "T.N.T.". Models of the containers were made, and it was confirmed through tests that the containers would not affect the bursting of the bomb or the scattering of the irradiated material in the area of the explosion. Aerial field tests of the bomb were also performed, with complete success.

Attachment nr. 5 contains design specifications for the Qa'qa' 28 bomb.

A series of calculations was made to estimate the best circumstances for explosion, to produce maximum effect in the explosion area. It was clear from these tests that the optimum situation would be to produce an aerial explosion at a height of 10 to 40 meters, since it would be expected that the irradiated material would fall in an approximately 350-meter diameter circle, producing a clear biological effect on anyone in the area during the explosion or up to a week afterward. It was evident from the experiment performed on the ground that there was an acceptable congruence between the theoretical calculations and the actual results.

Calculated estimates were made (Attachment nr. 2) on a number of the bombs effective in a set target occupying 12 square kilometers. These calculations used
estimation methods based on realistic assumptions in order to hit the enemy with a dose of radiation amounting to 2 Sievert = 200 REM = 200 RAD. This is the dose of the fourth stage referred to in Table A, which has been shown to inflict a number of symptoms of illness, with death expected to follow within two to six weeks although recovery is possible. The required charge to cover one square kilometer is 71 charges, or five irradiation batches at 17 charges per batch.

Other calculations were made to achieve the same injury rate with a wind speed of 2 M/second. The results showed that there would be a need for 1670 charges, i. e. 84 irradiation batches at a rate of 1- 2 days per batch.

To inflict losses by external exposure to the falling irradiated material, our calculations show that large numbers of charges are reeded to produce the same effect. However, if we think of the second stage effects of Table A (nausea, other symptoms), approximately 9 batches are needed.

Closed bombs will cause compound effects, some resulting from direct radiation from the irradiated material falling to earth and others from the irradiated material floating in the air. This material will enter the body through the respiratory system and may also enter the digestive system through polluted food or water, or enter the body through wounds. The overall effect will be the total of all these things.

Zirconium was chosen as a charge because it is used primarily in bombs as an incendiary material and therefore adds nothing new to ''the line of work". Zirconium 95 has a somewhat short half-life of 75.5 days, which helps to dissipate the effect of the bomb after several weeks so that it is difficult to track, analyze, or recognize it after that period. This gives sufficient time for the desired biological effects to take place, especially when there are multiple bombings. It would also be possible for our units to go to the bombed area without great danger after this period has expired.

The weapon will weaken enemy units from the standpoint of health and inflict losses that would be difficult to explain, possibly producing a psychological effect. Suggested uses are:

• Areas where troops are expected to be massed
• Industrial centers
• Airports
• Railroad stations
• Fortified defense areas where the enemy is holding firm
• Bridges and troop crossings
• Any other areas the command decrees

Attachment 5 shows detailed schematics of the final design of the Al-Qa'qa' 28 bomb.

The calculations in Table nr. 1 of Attachment nr. 6 indicate that the zirconium is acceptable in terms of the security of the reactor.

The contents of this report clearly show that the joint efforts of the Atomic Energy Agency and the Military Industrial Commission have resulted in the capability of manufacturing a bomb containing zirconium irradiated for a period of 12-24 hours. The bursting of this bomb will cause the usual effects of the traditional bomb and will add a biological effect which will strike the enemy in the first degree with regard to external exposure, and the degree increases with internal exposure (inhalation). It is clear from our calculations that hitting a point with 33 bombs will lead to the deaths of all personnel within a ten-meter radius of the center, given normal weather conditions. The cause of death will be exposure to radiation.

The principal limitations are:

A. One batch of 17 charges can be irradiated in a day. The radioactive strength/danger lessens (cools) after 4 days. After that, it must be used in bombs and dropped on a target without delay because the effectiveness of the irradiation decreases with time. The period between irradiation and use cannot exceed one week. Note that once the modifications to the reactor reservoir are completed, it will be possible to irradiate 20 charges in each batch.
B. Weather conditions should include as little wind as possible and normal conditions to ensure optimum distribution of the irradiated material in the air and on the ground. This is one limitation, because different weather conditions will greatly decrease the effectiveness of the biological factor to the limits of the first or second stage, and the effects will not appear until after a very long time has passed.
C. All of the work in its entirety must be in accordance with the IAEA guidelines so that none of the workers makes a mistake which will expose him to radiation.
D. Because of the lack of technical awareness this work must be done in strict secrecy, even with regard to those doing the work, so as not to give rise to psychological feelings leading to hesitation because of a fear of radiation. Those in charge must be completely aware of their roles.
E. It must be certain that the bomb will explode by installing more than one fuse to detonate it so that if it does not explode in the air it will explode on the ground.
F. If the enemy were to carry out a specialist physical analysis of the of the dust/soil shortly after the explosion then it would be possible for him to arrive at the nature of the radio-active material the degree of its affect etc.
G. It may be possible for radiation measuring equipments in satellites to record the effects of strong explosions when a concentrated strike is attained at one time.

3. The biological effects of ionised radiation (Table A)

Ionised radiation has known biological effects on man, they are somatic when they appear on a person exposed to radiation and genetic when they appear on future generations. When the dose to which a person has been exposed excedes a certain value rated as O.1 sievert = 10 rem = 10 rad approximately then it is probable that active effects of radiation will appear, this value depends on the nature of the person exposed and the conditions of exposure, it is not likely that clear effects would appear when the dosage is less than this value.

Example of the exposure referred to above are: -effects on the skin, breaking of the lens of the eye, effects on bone marrow cells which cause blood disorders and sterility problems.

When the dosage is more than this value then the effects are in co-relation to the amount of the dosage, the more the dosage increases the more serious are the effects.

Here are physical effects which appear afterwards such as cancer of the lung and luekemia and certain other malignant dieases.

In the event of low dosage with no defined rate of exposure, then the principle of protection against radiation is based on the fact that there is no safe dosage of radiation, and that it is necesary to keep the rate of exposure to the minimum. Certain examples have been given when the whole body has been exposed to dosage at the following rates:-

100 rad = 1gray and there will be nausea and vomitting, if the dosage is more then the bone marrow will be effected.
25 rad = 0.25 gray may cause sterility for three years.
10 rad = 0.1 gray may cause temporary sterility for one year.

Physical effects are one of the important factors in war.

Probable ways of exposure

External exposure: Mainly from gamma rays and partly from beta particles.

Internal exposure: As a consequence of inhalation and swallowing radioactive materials and contamination of wounds.

3. Calculated assessments.

The container of the radioactive material is pulverized and airborne which effectively spreads its contents of Zirconium dependent upon wind speed and direction.

We presume that the explosion can take place in two instances, the first on the earth's surface and the second 30 metres above the surface of the earth.

Attachment Nr. 2 gives details of the calculated assessments to bring about the required effects.

TABLE A
Probable effects of seious radioactive dosage on the whole body

1 sievert = 100 rems = 100 rads (approximately)

Examples

If the concentration of Zirconium in the air = 200 micro-curies/cubic metre

1becquerel = 27.03 x 10^-12 curies

= 27.03 x 10^-6 micro-curies

200 micro-curies/cubic metre = 200/ 27.3 x 10^-6 becquerel/cubic metre

=7.4 x 10^6 becquerel/cubic metre

lf we know that the amount a normal man breathes = 1.3 cubic metre/hour
In one day = 1.3 x 24 = 28.8 cubic metres

The amount of radiation inhaled in a day =7.4 x 10^6 x 28.8

= 213.12 x 10^6 becquerel/day

The factor for converting into the Zirconium equivalent = 4.09 x 10^-9

• Dosage = 4.09 x 10^-9 x 213.12 x 10^6

= 871.66 x l0^-3 sievert/day

= 0.871 sievert/day

We have learnt that the rate of radioactivity of a radioactive charge is 10% after the first week after the period of radiation has ended and in the case of the fourth week after the radiation the radioactivity will have reduced by about 30% of the initial levels.

4. The radioactive effectiveness of the charge.

The radioactivity.

A sample has been prepared to test the actual explosion in the first place and to observe qualities of the physical values during radiation.

1. Weight of the sample 2.400 grammes [sic]
2. Radiation tube nr (16) horizontal in reactor 14 July
3. Period of irradiation 14 hours.
4. Neutron bombardment in the region of 10^12 neutrons/sq cm/sec
5. Temperature on the surface of the sample 58 deg Centigrade
6. Power of the reactor 4.5 MW

After irradiation the sample was introduced to the hot cells for study, its physical condition was very good it was then placed into a lead container.

On Sat 22/8/1987 the level of radiation to the irradiated sample was measured from outside the lead container by touch and from various distances from the end of sample as shown in the diagram. The diagram shows the variations in the radioactive dosage in the sample, as there are 0.1 milli roentgen/hour opposite the top part of the sample, it then rises gradually as we approach the lower part
until it reaches a maximum of 2.5 milli roentgen/hour in the second third, then gradually reduces to 0.2 milli roentgen/hour at the bottom of the sample but the level of exposure for the sample outside the container is given at attachment (1) as it gives the above reading to the value of 25 roentgen/hour by contact and the highest reading by the above method is 0.20 roentgen/hour and the lowest reading is 2.5 roentgen/hour.

0.1 mR/hr
0.1 mR/hr
0.1 mR/hr
0.25 mR/hr
0.7 mR/hr
1.5 mR/hr
2.5 mR/hr
1.8 mR/hr
0.5 mR/hr
0.2 mR/hr

Note.

The details of this test are given in attachment (1)

5. Practical field tests

The field tests aimed for the following:-

a. The first test.

This test was carried out in al-Haswa range on Tuesday 18/8/1987, to check whether it was possible to smash the lead cover of an irradiated charge.

The test succeeded and the blast wave was very strong and the radius of its noted effect was more than 300 metres, and from a test the establishment carried out it was considered that the blast's killing effect was 200 metres from the centre of the explosion.

b. The second test (attachment Nr 2)

This test was carried out in the Western Desert on Thursday 27/8/1987. This test aimed mainly to find out how irradiated matter spread.

This test also included the preparation of the bomb and its delivery to the proposed location and then to carry out field reconnaisance of the area.

The operation demanded personal protective material to ensure the safety of the personnel measuring the level of radiation after the explosion, the wind speed was very high when the test was carried out - more than 8 metres/second. Levels of radiation were measured directly after the test, and rings of radiation were established around the site of the explosion and a programme was started for the contaminated earth.

Immediate readings showed that the level of radiation near the site of the explosion was more than the permitted limit for personnel operating in the radiation fields, also the results of the soil analysis indicated that it was 290 times that allowed for foodstuffs.

It was, however, not possible to measure the airborne part of the cloud which the wind took a long way. This was because there was basically very little irradiated material.

c. The third field test (attachment Nr 4)

This test was carried out in the Western Desert (aircraft firing range) on Monday 14/12/1987.

This test aimed to check the suitability of this weapon for use by aircraft and this was done in two stages. The first was the firing of a [possibly "projectile"] to check on the detonation mechanism and the second the actuality of there being a radioactive charge and using timed fuses to explode it on the surface.

Aircraft payload was one bomb in every case.

The cloud from the explosion rose more than 30 metres above the surface of the earth it was then dispersed by the wind, wind strength was in the region of 2 metres per second. The particles falling down near the centre of the explosion indicated that the two bombs had fallen within 15 metres of each other and the increased level of radiation began as we were still approaching the centre of the explosion at a distance of more than 80 metres.

The highest levels of radiation showed that, at a distance of some 10 metres from the centre, they were in excess of 3 milli rad/hour, this is the highest permissable level for those operating in radioactive fields.

The radioactivity on the contaminated soil, however, reached (7297) which is more than the maximum permissable for food.

The methods of calculation referred to in attachment (2) are unmeasured assessments for which there is no previous parallel and it differs from known estimates for cases of the spreading of radiation after nuclear explosions.

One of the assumptions pointed to the possibility of death occuring after two weeks for people inhaling irradiated material for two minutes and carried by (710) charges if the wind speed was one metre per second, on the assumption that they are within an area measuring 12 square kilometres, but there is a probability that 100% of personnel 150 metres from the target would die if 23 bombs fell on the target.

The incidence of casualties as a result of external exposure requires a large number of charges on the target, the amount required is as high as 8330 charges.

The difference between the two incances is attributable to the requirements for external exposure being greater than those for internal exposure, one must consider both of the effects on the enemy.

Attachment Nr. 7 refers to the opinion of Air Force Command concerning the success of loading and dropping the bombs with certain proposals concerning their requirements.

6. Preparations for formal production

The preparation for production is formal in the reactor, but in order to check on the maximum capabilities for full exploitation of the vertical tubes in the reactor (there are 20) calculations were made which indicate that the operation to irradiate 20 tubes in the heart of the reactor does not pose any danger because of the reaction or the temperature.

Certain modifications were also carried out on the reactor tank, and some cages were made out of special aluminium for cooling in the tank, and vertical tubes and lead containers to receive the irradiated charges.

Then the charges are actually irradiated and taken out from the tank of the reactor straight into the lead containers once, securely to the loading place in complete secrecy.

According to our estimates this test will take two weeks; then it will be possible to give a full and definitive description of all the operations.

ATTACHMENT A

Details of the irradiation tests and adjustments to the charge.

The test
A zirconium container sample operation was carried out from the evening of Saturday 15/8/1987 to the morning of Sunday 16/8/1987.

The production stages and sample inspection foltow:-
1. Production

a. The container was made from three separate bits of pure aluminium as in diagram (1).
b. Pressing and welding of section 3 with section 2 in diagram I and the two sections were examined by exerting pressure on them.
c. Filling and loading the container with 50 gr of zirconium oxide (ZrO) and pressurizing it inside the container io eliminate the presence of any air in it.
d. Insert pieces of compressed zirconium previously prepared to a length of 10 cm each into the container then compress it a second time
e. Weld section 1 to section 2.
f. Carry out a thermal test on the parts which had been joined together.
g. Fix a group from the thermo couples as in diagram 2 as follows:-

• Middle of the sample at a distance of 30 cm from the lower end Tc-l.
• Middle of the heart of the reator at a distance of 32.5 cm from the lower end Tc-2.
• At the end of the upper sample Tc-3 to measure the temperature of the water inside.
• At the lower end of the sample Tc-4 to measure the temperaure of the water outside.

Diagram 7
[diagram]
Cross section showing distribution of temperature in the sample and covers irradiated in tube Nr 16

Diagram 8
[diagram]
Cross section showing distribution of temperature in the sample and covers irradiated in tube Nr 16

Diagram 9
Cross section showing distribution of temperature in sample and covers irradiated in tube Nr 20

Diagram 9
[diagram]

Attachment NR 2
Methods and mathematical calculations

Method of calculating dosage rate.

1. External exposure to Gamma rays
The dosage rate is calculated in Rad/hour with an accuracy of +/- 20% according to the following equation:-

"exposure rate (R/h) = 6 x C (Curie) x E(Me V)

Taking that the source is a radioactive point ranging in power from 0.07 to 4 million electron volts, or a more accurate way of calculating the rate of dosage is to use the constant of Gamma :-

D ( R/h = (Rhm/Ci) A(Ci)

r^2 (m^2)

2 Internal exposure (inhalation)
Dosage suffered = Average amount of air inhaled

x Concentration of the radioactive material
x Conversion factor of the radioactive matter.

3. Calculations for the concentrations of air inhaled

We note from table 2 that in average conditions the highest concentration is 38 Micro curies per cubic metrc at a distance of 590 metres from the centre of the explosion.

The highest level permissable for bodily damage ''MPBB"

for Zirconium = 20 Milli curies

The highest permissable concentration in the air for the workers is:-

3 x 10 Milli curies per cubic cm

= 3x10^-2 Milli curies per cubic metre

38___ = 13 x 10^2 = 1300 times more than the maximum permissable
3 x 10^-2

This number scientifically represents the limit which it is not pemissable to excede for workers in the radioactive fields on health grounds .

4. What is needed for internal exposure by inhalation

a. First method

What is required is the sievert dosage of the fourth stage in table O page 4 which causes death after two weeks = 200 Rems for the period of one minute in the air

The dosage suffered = average amount of air inhaled x effectiveness of the matter x conversion factor

2. Sievert = 1.2 cubic metre/hour x becquerel (effectiveness) x 4.09 x 10^-9
Sievert/becquerel

(becquerel) effectiveness =
_ _____3 Sievert_____._
(1.2/60) cubic metre/minute x 4.09 x 10^-9 Sievert/becquerel

when 1 Sievert = 27.02 x 10^-12 Curie

= _______3_________
0.02 x 4.09 x 10^-9

= 24.45 x 10^9 becquerel

= 24.45 x 10^9 x 27 x 10^-12

= 660 x 10^-3

= 0.66 Curies per cubic metre will cause the fourth stage for every minute

When the one charge = 390 milli curies/Kgm
and the weight of the charge = 2.4Kgm
therefore effectiveness of each charge = 936 milli curies
=0.936 Curies

The one charge (0.936/0.66) = 1.42 metres for the occurrence of fourth stage casualties per one cubic metre per one minute

speed of wind 1 m/sec = 60 m/min
Dimensions of the rectangle 2 km x 6 km = 12 square km

6000 = 100 minutes to cover the distance
60

To get the required concentration on the path of 6 Km we need .100 = 70.42
1.42
= 71 charges approximately for one line

We assume that one bomb after exploding will adopt a conical path and the conical paths for a number of bombs exploding on one line will blend into each other when the distance between one and another is 200 metres on the width of a target of 2 Km

This means that the number required is (2000/200) = 10 one [comment:- possibly means units] to cover the width of the target.

lf the total number required is = 10 x 71= 710charges

(710) charges equals (71/20) = 35.5

= 36 loads of radiation at the rate of 20 charges per batch.

b. Second method

Table Nr A, settled conditions at a distance of 300 metres from the centre of the explosion, wind speed 1 m/sec the concentration equals 5100 micro curies/cubic metre.

= 370 x 10^-6 Curies/cubic metre = 370 x 10^-6 x 3.7 x 10^10 becquerel/cubic metre

= 1369 x 10^4 becquerel/cubic metre

Rate of human inhalation = 1.2 cubic metres/hour

Using the calculations given in Table A it is possible to select the most favourable and ideal atmospheric conditions and distances to achieve the optimum effects.

It clearly appears that when the bomb is exploded on the surface then the radioactive concentration at a distance of 150 metres from the center of the explosion when the wind speed is 2 m/sec is 20,000 micro curies/cubic metre but this concentration reduces as we move away from the centre.

20 x 10^3 micro curies/cubic metre = 20 x 10^-3 Curies/cubic metre

= 0.02 Curies/cubic metre

When the casualties of the fourth stage for every minute of inhalation = 0.66 Curies/cubic metre.

therefore the one charge causes (0.02/0.66) = 2 x 10^-2 / 66 x 10^-2

= 0.03 times the incidence of casualties at stage four at a distance of 150 metres from the target.

This number represents the probability of personnel casualties with the symptoms of the fourth stage from one charge if they were at a distance of 150 metres from the centre of the explosion in these conditions.

If we wanted a 100 % probability then 33 bombs or approximately 2 radioactive batches are needed.

5. External exposure caused by surface contamination.

Table Nr 3 explains the distribution of the matter on the surface of the earth (micro curies/cubic metre) under various atmospheric conditions when the explosion is on the surface.

The maximum concentration at a distance of 150 metres from the centre of the explosion is 40 thousand micro curies/cubic metre when conditions are settled and wind speed is 1 m/sec in order that the following equation can be applied for the dosage rate (roentgen/hour) at a distance of 1foot

= 6 effectiveness (Curie) x power (million electron volts)

=6 x 40 x 10^3 x 10^-6 x 0.7

= 6 x 40 x 7 x 10^3 x 10^-7

= 1780 x 10

= 168 x 10^-3 rad/hour

If the personnel remain for a period of 40 days then the dosage

= 168 x 10^-3 x 40 x 24

= 161.28 rad for every square metre
If we know the area it is required to contaminate = 12 square Km

= 12 x 10^6 square metres
2 Sievert = 200 rad approximately

representing (161.28/200) = 0.8064

The one charge which will cause casualties of the fourth stage
The number of charges depends on the area to be contaminated.

The bomb is not the direct source of the radiation covering an area of ground, it is the contamination of the surface and the food stuffs on and their consumption which cause the internal damage

6. Activity required to cover an area of ground (external effects)

In order to calculate the activity required to cover a rectangle of ground with an area of 12 square Km and to cause a dosage of external exposure which would cause stage two casualties in table A, that is to say 25-100 Rem.

Let us assume that the dose for every square metre is 25 Rad.

Rate of activity (Curies) =
______25 Rad_____
6 x 0.7 (million electron volt)

= 5.95 Curie for one hour

Let us assume that the duration of the stay is 40 days
The active -required equals (5.95/40 x 24) = 6 milli curies per square metre

to cover an area of 12 sq Km = 12 x 10^6 square metres

We need 6 x 12 x 10^6 =72 x 10^6 milli curies

but the proportion which will be covered by the falling particles will be 1/16 of the total area

this means that we need (72/16) x 10^6 =4.5 x 10^6 milli curies

When the initial irradiation is 390 milli curie/Kgm and the secondary irraiation is 1170 milli curie/Kgm
=1.17 Curie/Kgm

and the one charge = 2.4 Kgm
or 2.4 x 1.17 = 2.8 Curies
and the irradiation load is 20 charges
or each load = 20 x 2.8 =56 Curies

6 4
therefore the number of loads required = 450 x 10^4/5.6 x 10^4

= 80.356 irradiation loads to inflict the required external effects.

b. Another example to calculate external exposure as a consequence of a radioactive charge when measuring the rate of radioactive dosage resulting from a charge with a reading of 25 Rad/hrs

When we assume that the source is a point - 30 Rad/hrs
If this charge fell on an area measuring one square metre and period of exposure was 40 days,

30 x 24 x 40 = 2880 rad for the full dose
when the fourth stage dose is 200 Rad

Therefore the number of doses which the charge will cause for this period of time within the area of one square metre

= 28800 = 144 times at fourth stage scale.
200

When the required area = 12 sq Km = 12 x 10^6

So the number of charges =(12 x 10^6/144) =8.33 x 10^6 =8330 charges

This requires (8330/20) = 417 irradiation loads

7. The relationship between concentrations in the air or on the surface with the distances from the centre of the explosion in various atmospheric conditions and at various altitudes.

a. The three explanatory drawings attached to table Nr A show the relationship between the concentrations in the air (micro Curies/cubic metre) with the distances from the point of explosion when at altitude zero from the surface of the earth. It also shows the relationship {with} the three atmospheric conditions (unsettled, moderate, settled)

The greatest concentrations occur at a distance of 200 metres from the point of the explosion then fall off rapidly ever quicker as the distance increases. The highest level of concentration permissable in the air for workers in the radioactive fields is:-

3 x 10^-8 micro curies/cc

= 3 x 10^-2 micro curies/cubic metre

All the calculations given in Table A are much more than this concentration.
If a man standing at a distance of 2 Kms in the direction of the wind in unsettled atmospheric conditions breathed in and the wind speed was 4 m/sec we would find that he had received a dose of

(0.6/3 x 10^-2) = (0.2/ 10^-2) = 2 x 10^-1 x 10^2

=3 x 10

= 20 times the maximum amount allowed

The concentration of 0.6 micro curies per cubic metre referred to above is considererd to be very slight.

Now we have a high concentration calculated to reach 20,000 micro curie/cubic metre when conditions are settled and wind speed is averaging 2 m/sec at a distance of 150 metres from the centre of the explosion on the surface this means that the dosage equals

(20,000/ 2 x 10^-3) = 1x 10 more than the highest levels allowed

Table Nr 1, distribution of concentration (micro curies/cubic metre) in the air under various atmospheric conditions if the altitude of the source is:-

Graph
Actual altitude of the source = 0 metres from the surface of the earth

Weather - unsettlkd

Graph

Actual altitude of source = 0 metre from surface of the earth
weather moderate

Graph
Actual altitude of source = 0 metres from the surface of the earth

Weather settled

b. The three explanatory graphs attached to to table nr 2 represent the relationship between the concentration in the air (micro curies/cubic metre) and the distance from the point of the explosion when it is at an altitude of 30 metres from the earth's suface and also shows the relationship of the three types of atmospheric conditions (unsettled, moderate and settled)

The highest level of concentration is at a distance of 570 metres then decreases gradually.
All the calculations given in table Nr. 2 are much greater than the highest concentration permitted in the air this is 3 x 10^-2 micro curies/cubic metre.

Table Nr 2, distribution of concentration (micro curie/cubic mitre in the air under various atmospheric conditions if actual altitude of clouds is 30 metres