Event Notification Report for November 17, 2017

PART 21 - CHAPMAN GATE VALVE WEAK LINK ANALYSIS DEFECT

The following information was excerpted from a facsimile received from Crane Nuclear:

"This letter provides notification of a defect in a Weak Link Analysis provided to the Tennessee Valley Authority (TVA) by Crane-Aloyco, Inc. (CAI), a Crane Nuclear, Inc. (CNI) predecessor business unit, for a Chapman Gate Valve, Figure L900, Item # 18, Drawing CC05307, Revision B for the Browns Ferry Nuclear (BFN) plant.

"The subject valve was originally procured from Crane Chapman in 1968. In 1988, TVA requested Crane to supply a Weak Leak Analysis for the original valve. A Weak Link Analysis (OTC-258 Rev.0) was developed by CAI, which identified a maximum thrust capacity of approximately 112,000 lbf.

"In November 2017, Crane Nuclear, Inc. developed a new Weak Link Analysis for the valve. Crane Nuclear, Inc. provided the new Weak Link Analysis (WL-103 Rev. 0) to TVA on November 17th, 2017. Crane Nuclear. Inc. identified in the new Weak Link Analysis a maximum thrust capacity of approximately 96,000 lbf.

"CNI is reviewing our records to determine if the maximum thrust rating in any other Weak Link Analyses provided by CNI for gate valve designs with an SMB-4T or SMB-5T actuator exceeds the rating for the thrust bearings.

"Should you have any questions regarding this matter, please contact me, Joyce Hamman, Director, Safety & Quality at (678) 451-2280, Burt Anderson, Site Leader, at (630) 226-4990, or Samson Kay, Engineering Manager at (630) 226-4983."

AGREEMENT STATE REPORT - STOLEN MOISTURE DENSITY GAUGE

The following information was received from the State of California via email:

"On 11/17/17, the RSO [Radiation Safety Officer] contacted RHB [CA Radiologic Health Branch] to report a stolen moisture density gauge. The stolen gauge is a CPN Model MC-1DR, S/N MD90209216, containing 10 mCi of Cs-137 and 50 mCi of Am-241. The user had taken the gauge home and left it secured in the back of his truck. The truck was parked at his residence . . .. According to the user, most likely between midnight and 5 AM of 11/17/17, the chain locking the gauge to the truck bed was removed and the case was dragged behind a building where the locks on the box were broken and the gauge was removed. The box was recovered without the gauge. [The] RSO had notified San Jose Police Department of this incident (Event # P173210429). RHB will be following up on this investigation.

"5010 NUMBER (Date Notified): 111717"

THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

AGREEMENT STATE REPORT - MEDICAL UNDERDOSE

Eye plaque brachytherapy was being performed using I-125 seeds with a prescribed dose of 85 Gray. After the dose, the Iso-dose curve was noted to be different from the brachytherapy plan i.e. the dose was deeper than expected. Investigation revealed that a new model plaque was used which differed from the previous model. This resulted in an underdose with 65 Gray actually administered.

Oregon Report: 17-0073

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.