NRC Identifies Several Apparent Violations at Maine Yankee Following Three Investigations; Issues Demand for Information to Consultants Yankee Atomic & Duke Engineering

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No. 97-184

December 19, 1997


The staff of the Nuclear Regulatory Commission has notified the Maine Yankee Atomic Power Co. of several apparent violations of agency requirements following three investigations at the Maine Yankee nuclear power plant that formerly operated in Wiscasset, Maine. Some of the violations could lead to escalated enforcement, including civil penalties.

In addition, NRC has issued a Demand for Information, calling on the utility's technical consultants to demonstrate why the agency should continue to have confidence in their work.

The NRC investigations at Maine Yankee concerned (1) allegations made by an anonymous source two years ago about the adequacy of the facility's emergency core cooling system; (2) the plant's submittal to the NRC of inaccurate information regarding the capacity of the plant's atmospheric steam dump valves; and (3) falsification of records involving the electrical testing of equipment important to safety.

"Based on the extensiveness of the investigations, NRC does not consider that further information is necessary to make an informed enforcement decision," NRC Region I Administrator Hubert J. Miller said in a letter sent to Maine Yankee Atomic Power Co. However, he said, the NRC will not take enforcement action until Maine Yankee has an opportunity to either respond to the alleged violations within 30 days, or request a -decisional enforcement conference.

The Maine Yankee plant was shut down for repairs last December. On August 6, Maine Yankee's Board of Directors voted to permanently shut the plant.

With respect to the first item, the NRC's Office of Investigations concluded that between June 1990 and May 1993, Maine Yankee Atomic Power relied on an inadequate computer analysis to demonstrate the adequacy of its emergency core cooling system. As a result of limitations in the computer modeling, the NRC staff said, it could not determine whether the emergency core cooling system was capable of handling the most severe postulated accident that might have occurred at the plant. After a liminary inspection and meetings with the licensee, NRC ordered Maine Yankee to limit power output to a level at which the adequacy of the emergency core cooling system had been demonstrated.

"These apparent violations collectively resent a potentially significant lack of attention or carelessness toward licensed responsibilities and a failure to conduct adequate oversight of a vendor, resulting in the use of services of a defective or indeterminate quality," Mr. Miller said.

Investigators also concluded that in a 1986 submittal, the company "willfully provided inaccurate information" to the NRC regarding the capacity of the facility's atmospheric steam dump valves. The valves are used to vent steam from the plant during certain accident scenarios.

NRC investigators also concluded that in August 1996, two electrical engineers working at Maine Yankee falsified records of electrical testing of some plant safety-related equipment. Specifically, NRC investigators determined that the electrical engineers failed to conduct an electrical test as written in an approved work order, initialed the test record to give the appearance that the test had been satisfactorily conducted as written, and failed to note the change in the test method that was actually implemented.

In a related action, a Demand for Information has been sent to Maine Yankee's technical consultants, the Yankee Atomic Electric Company (acquired earlier this month by Duke Engineering & Services Co. of Charlotte, North Carolina) to obtain information NRC considers necessary to determine whether they should continue to provide engineering analyses, and in particular loss-of-coolant accident analyses, to NRC power reactor licensees. The Demand for Information, signed by Samuel J. Collins, Director of the NRC's Office of Nuclear Reactor Regulation, gives the companies 30 days in which to respond, under oath or affirmation.

Copies of the letters to Maine Yankee Atomic Power Co. and to Yankee Atomic/Duke are available from the NRC Public Document Room and have been placed on the NRC Homepage at http:\\.

Issuance of this letter to Maine Yankee does not mean the NRC has made a final determination that a violation has occurred or that enforcement action will be taken. Rather, the purpose is to discuss the apparent violations, their causes and safety significance; and to provide the licensee with an opportunity to point out any errors concerning the investigations.

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