ML19308C178
| ML19308C178 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/30/1979 |
| From: | Doyle B NRC - NRC THREE MILE ISLAND TASK FORCE |
| To: | Chipman G NRC - NRC THREE MILE ISLAND TASK FORCE |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001210514 | |
| Download: ML19308C178 (1) | |
Text
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>SKFGo UNITED STATES 8
NUCLEAR 3EGULATORY COMMISSION g
g nC WASHINGTON, D. C. 20555 k..... f July 30, 1979 MEMORANDUM FOR: Gordon Chipman FROM:
Bernard C. Doyle
SUBJECT:
CONTROL ROOM DESIGN LAYOUT
Reference:
Your memorandum July 24, 1979 In the referenced memorandum, you asked me to comment on the ways in which the control room design or layout may have contributed to the Ull-2 accident. W e following comments on the control room layout are very preliminary and based on a short visit to Bil where less than an hour was spent in the control room. The following are my comments:
1.
%e open position of the EMOV was not recognized by the CR Operator for two hours after it had opened due to high RCS pressure even though that pressure dropped below the rescating pressure 13 seconds after it had opened. The operators could have been lulled into a false analysis due to the indication that the electrical power was applied to move the valve to the closed position.
The actual position of the valve should have been indicated.
2.
The operators did not recognize that the emergency feedwater block s
valves were in the closed position for eight minutes after the feedwater pumps tripped. The indication was not immediately evident to the operators that the valves were closed.
Low 1cvel in the OTSB and de-creasing pressures alerted the operators to examine their pancis for cause. They discovered the closed valves during this examination. The indication that the valves were closed should have attracted the cperators to that fact.
3.
There was no indication in the control room as to the level of the RCS. Such an indication would have shown that the level was decreasing and that the core was going to be uncovered. This would have shown the need for llPI.
I realize that this is very brief and that the location of switches, meters and warnings may have played a part. The one visit, particularly with little information at that time as to what had occurred, did not equip me to observe such details.
I believe that another visit to the D1I-2 CR would be beneficial.
"h Bernard C. Doyle, Consultant NRC/DiI Special Inquiry Group l
cc:
E. K. Cornell R. C. DeYoung 8 001210 k