Event Notification Report for September 15, 2016

AGREEMENT STATE REPORT - FIXED GAUGE SHUTTER STUCK IN OPEN POSITION

The following information was received by the Commonwealth of Massachusetts:

"The licensee called the Agency [Massachusetts Radiation Control Program] to report a fixed fill level gauge stuck in the open position. The gauge is a Berthold LB7400 Series gauge, Model LB7440, and contains a 150 mCi Cs-137 source [S/N:1476].

"The gauge is mounted to a liquid holding tank which was emptied and was scheduled for routine cleaning. Before cleaning of the tank could begin, the gauge shutter was attempted to be put into the closed position. When attempting to close the shutter, the handle broke off and left the gauge stuck in the open position. Cleaning was not able to be performed and no one was able to enter the tank. The gauge remains in the installed position and is in an inaccessible area with safety controls in place to prevent access. The manufacturer was contacted and will be servicing the gauge 09/27/16 thru 09/28/16 by either repairing or replacing the shielding as necessary.

"The Agency continues to investigate and considers this event to be open.

"Manufacturer of gauge notified and will respond to assess the device; repair or replacement as necessary."

AGREEMENT STATE REPORT - LOST TRITIUM SIGN

The following report was received from the State of Texas via email:

"On September 15, 2016, the Agency [Texas Department of State Health Services] was notified by an Operation Specialist (OS) at the Chevron corporate office in Houston, Texas, that during an inventory of a storage room in their building, an 'EXIT' sign containing 7 curies of tritium was not located. The sign was manufactured by Isolite in October of 2002. The OS stated they have search the building and interview all their personnel who had accessed the room since the last inventory. He stated that it is possible that the sign may have been disposed of in their waste, but he does not believe that happened. Additional information will be provided as it is received in accordance with SA-300."

Texas Incident: I-9429

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

POTENTIAL UNANALYZED CONDITION BASED ON IDENTIFIED NON-CONFORMING CONDITIONS

"During performance of an extent of condition evaluation of protection for Technical Specification (TS) equipment from the damaging effects of tornadoes, Arkansas Nuclear One, Unit 1, identified non-conforming conditions in the plant design such that specific TS equipment on Unit 1 is considered not [to] be adequately protected from tornado missiles. The reportable condition is postulated by tornado missiles entering vital switchgear rooms 99 and 100 and striking vital switchgears in the rooms. A tornado could generate multiple missiles capable of striking the Unit 1 vital switchgear and rendering both safety related AC electrical trains inoperable.

"This condition is reportable per 10 CFR 50.72(b)(3)(ii)(B) for any event or condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety, and per 10 CFR 50.72(b)(3)(v) for any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to (A) safe shutdown capability, (B) residual heat removal capability, or (D) accident mitigation.

"This condition was identified as part of an on-going extent of condition review of potential tornado missile related site impacts. Licensee Event Report (LER) 50-313/2016-002-00 was recently submitted addressing previously identified tornado missile vulnerabilities at the Unit 1 plant.

"Enforcement discretion per Enforcement Guidance Memorandum EGM 15-002 has been implemented and required actions taken. Corrective actions will be documented in a follow-on licensee event report.

"The licensee has notified the NRC Resident Inspector."

POTENTIAL DEGRADATION OF ECCS PUMP PRESSURE INDICATORS

"During a review of commercial grade dedication records for a Unit 1 [Emergency Core Cooling System ECCS] Centrifugal Charging Pump discharge pressure gauge, it was identified that the process side of the diaphragm seal utilizes a Teflon (PTFE) gasket. Further review found Teflon (PTFE) to be installed in the pressure gauge seal assembly for all four of the Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2.

"Teflon (PTFE) is a restricted material normally prohibited from use in contact with reactor coolant or in radiation environments. Teflon (PTFE) is not radiation tolerant and significantly degrades in a radiation environment. The Teflon (PTFE) used in these pressure gauges could fail during a LOCA [Loss of Coolant Accident] which could cause the [ECCS] Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2 to be inoperable, and exceed system leakage limits. Excessive leakage from systems which would contain post-LOCA recirculation fluid would challenge onsite and offsite dose estimates and in-plant post-accident accessibility. This represents an unanalyzed condition.

"Currently, the pressure gauges for all four of the [ECCS] Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2 have been isolated until this issue can be further evaluated. Luminant Power believes that the Teflon (PTFE) has existed in the pressure gauges since initial plant licensing. Luminant Power is currently investigating the extent of the condition and repair techniques.

"The NRC Resident Inspector has been notified."

* * * RETRACTION AT 1634 EST ON 11/14/16 FROM DANNY BRADFORD TO JEFF HERRERA * * *

"On 09/16/2016, Comanche Peak reported an ENS Report (no. 52244) related to the identification of teflon-containing pressure-seal assemblies installed on the suction and discharge sides of the centrifugal charging pumps and on the suction side of the positive displacement pump. The technical concern was the potential for the teflon-containing assemblies to leak if subjected to post-LOCA recirculation fluid and associated radiation levels.

"Subsequent investigations by Engineering have determined: (1) the centrifugal charging pumps were operable for all postulated non-LOCA design bases events which required their operation and (2) for postulated LOCA scenarios which would involve radiation levels sufficient as to call into question the ability of the teflon-containing assemblies to maintain system pressure boundary, the ECCS function would be fulfilled in the event one or all of the charging pumps had to be removed from service (due to system leakage) and limiting (control room) doses would have remained below applicable regulatory limits.

"Based on the above, the condition described in ENS report no. 52244 is not considered to be an un-analyzed condition as described in10 CFR 50.72(b)(3)(ii)(B), nor is it considered to be a condition which could have led to a potential uncontrolled radiation release per 10CFR 50.72(b)(3)(v)(C), nor is it considered to be a condition which could have prevented fulfillment of a safety function under 10 CFR 50.72.(b)(3)(v)(D).

"The NRC Resident Inspector has been notified."

Notified the R4DO (Azua).