Event Notification Report for December 20, 2011

PART 21 - UF6 ACCUMULATOR TANK HAD THROUGH WALL CRACKS THAT CAUSED LEAKAGE

The following information was received via facsimile:

"On October 26, 2011, the discovery of two (2) defects (cracks) was identified on the north head of the Building C-310A side accumulator vessel. The accumulator is a tank used to provide a storage volume for liquid Uranium Hexafluoride (UF6) during the product withdrawal process, and it can hold up to 20,000 pounds of UF6 liquid. The defects in the 48" UF6 side accumulator allowed a small release of material which produced a process gas leak detection alarm on October 21, 2011

"Investigation to determine the cause of the cracks has revealed that the base metal contained stress defects which allowed multiple cracks to form with some of the cracks penetrating through the outer wall causing the vessel to leak. These cracks were a result of fabrication deficiencies and not the use of the vessel. There are nine (9) similar basic components used in Buildings C-310 and C-315. However, the other nine (9) vessels were not manufactured by Westerman Companies, the firm which designed and fabricated the defective vessel.

"The C-310A side accumulator has been repaired by cutting out the area of the defect extending into the unaffected areas of the base metal in accordance with ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. USEC held a meeting with a representative of Westerman Companies on November 22. 2011, to discuss the defect."

UNPLANNED CONTAMINATION DUE TO MEDICAL TRANSPORT OFFSITE

"An employee was complaining of chest pains this morning about 0830 CST. The plant nurse evaluated the employee and concurred with a decision to transport the employee to a regional hospital. The employee was transferred to a regional hospital while wearing his plant clothing. Contamination was present on the employees clothing. There was 2,250 dpm on a small area on the back pocket. The coveralls were collected and placed in a plastic bag at the hospital. The gurney, ambulance, and hospital facility was surveyed and no contamination was detected.

"The employee's plant clothing was returned to the plant for disposal."

Contamination was from uranium ore concentrates.

PART 21 - CAPACITY FAILURE OF PRESSURE RELIEF VALVE

The following information was received via facsimile:

"A potential issue exists involving Dresser's pressure relief device model 1982. The Part 21 investigation was initiated because of a nameplate capacity failure during National Board certification testing. The Dresser model 1982 pressure relief device is used for system overpressure protection. Dresser's engineering and quality assurance departments are currently working to identify the root cause of this capacity failure and to determine if the equipment is being used in safety related applications subject to 10 CFR Part 21. Should it be determined that the equipment at issue is being used in safety related applications, a notification will be provided in accordance with the requirements of 10 CFR Part 21."

* * * UPDATE AT 1431 EST ON 1/9/12 FROM PHILIP WALTZ TO HUFFMAN VIA FACSIMILE * * *

The following is a summary of an interim report on this issue:

"During the investigation process of 10 CFR Part 21, File No. 2011-02, in accordance with 10 CFR Part 21, GE Dresser has not been able to obtain the required flow capacity and does not have the required information regarding the system to determine the required flow capacity of the valve in question.

"We have completed a Transfer of Information in accordance with 10 CFR Part 21.21 (b) to Entertech and Exelon to assist in the determination of Part 21 reportability.

"The Transfer of Information letter [below] has been sent to Enertech and Exelon.

"GE Dresser supplied a pressure relief valve dedicated as ASME Section VIII Safety Related to Enertech, which was then sold to Exelon and installed at the Dresden Nuclear Power Station, Unit 2. As a result of an investigation of the effect of outlet piping on the flow capacity of similar pressure relief valves it was noted that the pressure relief valve installed at Dresden, Unit 2 may not relieve its ASME certified flow capacity when installed with outlet piping. In order to determine if a reportable condition exists, the flow capacity provided by a pressure relief valve to prevent the protected system from exceeding a pressure 10% greater than systems design pressure is required. GE Dresser has not been able to obtain the required flow capacity and does not have the required information regarding the system to determine the required flow capacity. As such GE Dresser cannot determine if the identified deviation from technical requirements would create a reportable condition within the requirements of 10CFR Part 21. GE Dresser provides this Transfer of Information, in accordance with 10 CFR Part 21.21(b) to Enertech and Exelon to assist in the determination of Part 21 reportability."

NRC R3DO (Orth) and R4DO (Lantz) have been notified. The NRC Part 21 Group has been sent a copy of this interim report.

* * * RETRACTION AT 1315 ON 3/19/2012 FROM WILLIAM ALEXANDER TO MARK ABRAMOVITZ * * *

The following report was received via fax:

"During the investigation process of 10 CFR Part 21 File No. 2011-02, in accordance with 10CFR Part 21, GE Dresser was not able to obtain the required flow capacity and did not have the required information regarding the system to determine the required flow capacity of the valve in question.

"We completed a Transfer of Information in accordance with 10CFR Part 21.21(b) to Enertech and Exelon to assist in the determination of Part 21 reportability. This information was attached to our previous Transfer of Information letter.

"We have received updated information from Entertech and Exelon. Upon receiving 10CFR Part 21 notification from Dresser, Dresden Design Engineering performed an evaluation and has concluded that their system will produce a flow, for this valve, much less than the minimum flow valve determined by test of a representative valve. Upon receipt of system flow capacity from Dresden, GE Dresser's Engineering department has confirmed the valve in question will operate according to Dresden requirements.

"The above information clears the one valve which was in question for this 10 CFR Part 21 reportable.

"GE Dresser is filing this retraction letter to state we do not have a reportable issue involving a pressure relief device type 1982 valve and therefore closing our 10CFR Part 21 File No. 2011-02."

Notified the R3DO (Kunowski) and Part-21 Group (e-mail).