Those improvements will be subject to prior approval by the reliability council and the Federal Energy Regulatory Commission.
The Sealing Reliability Council of the Pressure Vessel Research Council (PVRC) is carrying out a survey of flat face flange designs.
Utilities now operate under voluntary guidelines developed by the reliability council, which in practice means no one has to comply.
A spokeswoman for Mr. Abraham said the primary source for the number was the statement issued by the reliability council.
The North American Electricity Reliability Council, the group responsible for grid reliability, has a big investigation under way.
The reliability council, also called NERC, assembled the record for its own investigation and for a task force created by the Department of Energy and the Canadian Ministry of Natural Resources.
"That should not have resulted in any overload of any other piece of equipment on the system," said Howard F. Illian, a consultant who has worked for the reliability council.
The assessment by the reliability council, issued in May, would have been seen by virtually all controllers of the grid nationwide, said Mary Lynn Webster, a spokeswoman for the Midwest Independent System Operator.
Officials with the reliability council confirmed that the mention of potential cascading power failures in the region was a significant warning.
But a surplus of energy could have caused a transmission line to fail, said Robert Blohm, an energy consultant who serves on a committee advising the reliability council.
