Well, INSAG-7 is 148 pages that I will not read in full, as Chernobyl is not my primary interest. But I did find this in it:
5.2.2. Departure from test procedures
It is not disputed that the test was initiated at a power level (200 MW(th)), well below that prescribed in the test procedures. Some of the recent comments addressed to INSAG boil down to an argument that this was acceptable because nothing in normal procedures forbade it. However, the facts are that:
— the test procedure was altered on an ad hoc basis;
— the reason for this was the operators’ inability to achieve the prescribed test power level;
— this was the case because of reactor conditions that arose owing to the previous operation at half power and the subsequent reduction to very low power levels;
— as a result, when the test was initiated the disposition of the control rods, the power distribution in the core and the thermal-hydraulic conditions were such as to render the reactor highly unstable. When the reactor power could not be restored to the intended level of 700 MW(th), the operating staff did not stop and think, but on the spot they modified the test conditions to match their view at that moment of the prevailing conditions. Well planned procedures are very important when tests are to take place at a nuclear plant. These procedures should be strictly followed. Where in the process it is found that the initial procedures are defective or they will not work as planned, tests should cease while a carefully preplanned process is followed to evaluate any changes contemplated.
5.2.3. Other deficiencies in safety culture
The foregoing discussion is in many ways an indication of lack of safety culture. Criticism of lack of safety culture was a major component of INSAG-1, and the present review does not diminish that charge. Two examples already mentioned are worthy of emphasis, since they bear on the particular instincts required in reactor operation. The reactor was operated with boiling of the coolant water in the core and at the same time with little or no subccoling at the pump intakes and at the core inlet. Such a mode of operation in itself could have led to a destructive accident of the kind that did ultimately occur, in view of the characteristics of positive reactivity feedback of the RBMK reactor. Failure to recognize the need to avoid such a situation points to the flaws in operating a nuclear power plant without a thorough and searching safety analysis, and with a staff untutored in the findings of such a safety analysis and not steeped in safety culture. This last remark is especially pertinent to the second point, which concerns operation of the reactor with almost all control and safety rods withdrawn to positions where they would be ineffective in achieving a quick reduction in reactivity if 19 shutdown were suddenly needed. Awareness of the necessity of avoiding such a situation should be second nature to any responsible operating staff and to any designers responsible for the elaboration of operating instructions for the plant.
Sound like HBO’s Chernobyl only erred in making it seem like only Dyatlov was negligent that night, as opposed to everyone in the room. But even without that, the series does show the big takeaway was that the USSR as a whole was negligent.
Well, INSAG-7 is 148 pages that I will not read in full, as Chernobyl is not my primary interest. But I did find this in it:
Sound like HBO’s Chernobyl only erred in making it seem like only Dyatlov was negligent that night, as opposed to everyone in the room. But even without that, the series does show the big takeaway was that the USSR as a whole was negligent.