Diagrams decoding. 

The moving of control rods in the last 4 minutes is not less interesting than the change of power to understand the course of emergency process. After all, the cause of change of power is the reactivity which is strictly controlled by control rods. But the rods moving, as well as the reactor power, were practically not registered by DREG, and they are known only from diagrams recorded by CRU instruments with driving speed of 60 mm/h. Such accuracy of registration on time is sufficient for slow processes to that as process of power downfall to the level of 200 MW at 0 : 30. But in any way it is not enough for the description of physical processes in the reactor in last 4 minutes.
Nevertheless in the report of the Soviet experts for was presented a moving diagram of control rods AR1, AR2 and AR3 in a range of time from 1:18:30 till 1:23:50 (see picture 17). It obviously arose from the recorded diagrams decoding , that was executed in the Kurchatov Institute. Unfortunately, the primary information in the form of a copy of these diagrams (that looking at them to estimate possibility and reliability of such decoding) has not remained at least at the authors of this site disposal. But we can arrive on the contrary, represent these IAEs pictures in natural scale of the initial diagram and look how it will turn out. Thus it is necessary to consider that the images received thus are much more accurate, than natural, they are much more contrast also a thickness of a line on them essentially less (on picture 24 thickness of a line is 20 sec on time, and in nature it is not less than 30).


For descriptive reasons together with these images on the same picture are presented images of decoding of diagrams in a range of time from 0:30 to 1:19, executed in WNIIAES. This decoding do not contain details of movement of rods (which cannot be precisely interpreted because of the low resolution on time) and represent registration points, connected by straight lines. Two of such registration points are known from listings of the operation routine [PRIZMA], and they are precisely adhered on time 0:39:03 and 1:22:37.
On IAEs diagram area too it is possible to pick out registration points. In the beginning of this range of time [AR] rods move upwards, then time most part they are at a stop and then in the end of a range move direct down to landing on BLS (bottom limit switch). Obviously these registration points are represented on the diagram Pic. 17, as points of DREG registration.
In the report of experts for IAEA avoided tremendous force fact. From 1:19:57 till 1:23:11 , i.e. almost during all range of time shown on the diagram, [AR] has been disconnected on malfunction. Not to tell about this at all is impossible, it would be direct forgery. Therefore it is marked in the report on the picture of diagram at the moment of time 1:23:11 "malfunction of [AR] is removed". And it is no more words when it has arisen, what consisted of, how many lasted, total silence in general.
As a result, there was a diagram "with tarnished reputation", looking at which (in natural scale), the only thing that it is possible to tell, is that in the beginning (before occurrence of a signal of malfunction) rods go upwards, obviously compensating negative reactivity, and in the end (when malfunction has already been removed) are moving downwards, as it is visible on SCRAM signal from the button, till landing on bottom limit switch. And became this diagram (in a kind of Pic. 17) a source of the primary information on movement of the rods, incontestably testifying to occurrence in the reactor of the great positive reactivity (with which CSS does not cope) long before any pushing of SCRAM button.

The desire of all researchers of Chernobyl accident to learn what occurred last minutes of the reactor existence has appeared so strong and the authority of the Soviet experts writing the report for IAEA was so great that nobody has asked a question whence the diagram of [AR] rods moving undertook in the report, whether and so all was actually. The diagram drawn on the picture 17 has got a settled status of the primary information. Even A.S.Djatlov seeing all the eyes but writing the book 5 years later, has not called in it in question this picture.