Event Notification Report for March 26, 2018

TEMPORARY LOSS OF CONTROL ROOM ENVELOPE BOUNDARY

"At 1058 Eastern Daylight Time (EDT) on March 26, 2018, a Main Control Room (MCR) alarm was received for low control room positive pressure.

"At 1100 EDT, a Control Room Envelope (CRE) door was found ajar and immediately closed. Technical Specification 3.7.10, Control Room Emergency Ventilation System (CREVS), was declared not met for both trains and Condition B entered.

"At 1100 EDT on March 26, 2018, the alarm cleared, CREVS was declared operable and LCO [Limiting Condition for Operation] 3.7.10, Condition B was exited.

"The safety function of the CRE boundary is to ensure the in-leakage of unfiltered air into the CRE will not exceed the in-leakage assumed in the licensing basis analysis of Design Basis Accident (DBA) consequences to CRE occupants. From 1058 EDT to 1100 EDT, WBN [Watts Bar Nuclear] was unable to validate that CREVS could fulfill its required Safety Function.

"This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D)."

The NRC Resident Inspector has been notified.

AGREEMENT STATE REPORT - STOLEN MOISTURE-DENSITY GAUGE

The following is an excerpt from a report received from the State of Nevada:

"At 1000 PDT on March 26, 2018, the State of Nevada Radiation Control Program was informed by Aztech Materials and Testing, LLC, that a Humboldt, Model 5001EZ, Serial Number 3491, containing 10 mCi of cesium-137 and 40 mCi americium-241:beryllium, was stolen from the licensee's vehicle. The gauge was secured with two locks in the back of a pickup truck. The State is following the incident and working with local authorities to develop a press release. Local law enforcement and the FBI have been notified. Follow-up information will be provided to NRC on the recovery of the stolen gauge and entered into NMED (Nuclear Material Events Database)."


* * * UPDATE FROM JOHN FOLLETTE TO DONALD NORWOOD AT 1730 EDT ON 3/28/2018 * * *

The following information was received via E-mail:

"The State of Nevada Radiation Control Program has been informed by the Las Vegas Metropolitan Police Department that the stolen portable nuclear gauge has been recovered. Below is the notification:

"'All items were recovered in a stolen vehicle (abandoned, no suspects located). Patrol officers will be releasing the items back to Aztech.'

"The NMED report will also be updated."

Notified R4DO (Gaddy). Notified via E-mail ILTAB (Whitney) and NMSS Events Notification.

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

TEMPORARY LOSS OF CONTROL ROOM ENVELOPE BOUNDARY

"At 1839 Eastern Daylight Time (EDT) on March 26, 2018, a Main Control Room (MCR) alarm was received for low control room positive pressure.

"At 1840 EDT, a Control Room Envelope (CRE) door was found ajar and immediately closed. Technical Specification 3.7.10, Control Room Emergency Ventilation System (CREVS), was declared not met for both trains and Condition B entered.

"At 1840 EDT on March 26, 2018, the alarm cleared, CREVS was declared operable and LCO [Limiting Condition for Operation] 3.7.10, Condition B was exited.

"The safety function of the CRE boundary is to ensure the in-leakage of unfiltered air into the CRE will not exceed the in-leakage assumed in the licensing basis analysis of Design Basis Accident (DBA) consequences to CRE occupants. From 1839 EDT to 1840 EDT, WBN [Watts Bar Nuclear] was unable to validate that CREVS could fulfill its required Safety Function.

"This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D)."

A watch has been posted at the door to prevent recurrence.

The NRC Resident Inspector has been notified.

TECHNICAL SPECIFICATIONS REQUIRED SHUTDOWN DUE TO INOPERABLE MAIN STEAM ISOLATION VALVE

"On March 25, 2018 at 1833 CDT, while at 100 percent power, Farley Unit 1 (FNP-1) conservatively declared a single Main Steam Isolation Valve (MSIV) inoperable on the 1C Steam Generator line due to indication of Steam Generator pressure rise with a corresponding reduction in flow of that loop. FNP-1 began a reactor shutdown at 0400 CDT on March 26, 2018 to establish plant conditions to support testing the affected main steam line MSIVs while in the required action time of Technical Specification 3.7.2. At 1338 CDT on March 26, 2018, testing confirmed that the single MSIV was inoperable and that valve disassembly will be required. The duration of the valve repair would exceed the required action time of Technical Specification 3.7.2. This report is being made in accordance with 10 CFR 50.72(b)(2)(i), as a plant shutdown required by technical specifications.

"The licensee has notified the NRC Resident Inspector."

* * * UPDATE FROM DOUGLAS HOBSON TO KEN MOTT AT 0202 EDT ON 5/16/18 * * *

"This EN [event notification] is being updated to clarify the reporting criteria as 'Voluntary'. Farley Technical Specification 3.7.2 allows continuous operation in MODE 2 with an INOPERABLE MSIV as long as the other MSIV in the affected Main Steam Line is closed. The initiation of the shutdown was performed as a prudent action to repair and restore OPERABILITY of the affected MSIV and was not a requirement of the Farley Technical Specifications."

The licensee notified the NRC Resident Inspector.

The R2DO (Masters) was notified.