Officials with the reliability council confirmed that the mention of potential cascading power failures in the region was a significant warning.

The reliability council for the Texas Interconnection is:

The engineers already voted at an April session to endorse a proposal by the reliability council for a spacecraft to watch for incoming particles.

But Mr. Heckman and officials of the reliability council say it is not clear where the money would come from.

A spokeswoman for Mr. Abraham said the primary source for the number was the statement issued by the reliability council.

Ms. Vancko said the reliability council's statement referred to the total populations of six electrical-distribution regions affected by the blackout.

These control areas in turn operate under 10 "reliability councils," established by the utilities in the wake of the 1965 blackout in the Northeast.

Utilities now operate under voluntary guidelines developed by the reliability council, which in practice means no one has to comply.

The reliability council said it would "take firm actions" to improve compliance with its rules, including sending out inspection teams.

In the past, regional committees of the reliability council met to review rule violations, but did not report them to headquarters.