Event Notification Report for June 30, 2014

AGREEMENT STATE REPORT - LOST OR STOLEN NUCLEAR DENSITY GAUGE

The following report was received from the Commonwealth of Pennsylvania via facsimile:

"Notifications: The Department's [Pennsylvania Department of Environmental Protection and Bureau of Radiation Protection] Southwest Office received a phone call on July 1, 2014 regarding a lost nuclear density gauge. This event is reportable per 10 CFR 20.2201(a)(1)(i).

"Event Description: The nuclear density gauge in question was last used on Friday, June 27th, at a job site in Mt. Lebanon, PA. The employee who used the gauge, reported returning the gauge (in its case) to the licensee's storage area that afternoon. That same employee reported, at close of business on Monday June 30th, that 'the case was now empty.' An inspection by the licensee [revealed] the case and lock were both intact inside the locked storage area. There were no signs of forced entry and nothing else was missing. The employee has been questioned multiple times and maintains that the gauge was returned to the storage area in the case on Friday, June 27th. The licensee also went back to [search] the job site in Mt. Lebanon, but did not find the gauge.

"Gauge Model: Troxler 3411B, Serial # 5434, containing 9 mCi Cs-137 and 44 mCi Am-241 sources.

"Cause of the Event: Unknown at this time.

"Actions: The local police are being notified and the licensee is offering a reward for the return of the gauge. The Department issued a press release on July 1, 2014, with a photo of the Troxler gauge and noting the reward. The Department's Southwest Regional Office will conduct an reactive inspection. More information will be provided upon receipt."

PA Report #: PA140014

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.

PLANNED MAINTENANCE ON TECHNICAL SUPPORT CENTER VENTILATION

"At 0730 EDT on Monday, June 30, 2014, the Cook Nuclear Plant (CNP) Technical Support Center (TSC) charcoal filtration system was removed from service for scheduled maintenance. Under certain accident conditions, the TSC may become unavailable due to the inability of the charcoal filtration system to maintain a habitable atmosphere. Compensatory measures exist to relocate TSC personnel to the unaffected unit's control room if necessary. TSC ventilation system maintenance and post maintenance testing is scheduled to be completed by 1500 EDT on Monday, June 30.

"The licensee has notified the NRC Resident Inspector."

* * * UPDATE FROM JAMES SHAW TO VINCE KLCO AT 1327 EDT ON 6/30/14 * * *

The charcoal filtration system was restored to service at 1245 EDT on 6/30/2014.

The licensee will notify the NRC Resident Inspector.

Notified the R3DO (McCraw).

STACK HIGH RANGE RADIATION MONITOR OUT OF SERVICE FOR PLANNED MAINTENANCE

The Unit 2 stack high range radiation monitor was removed from service at 1310 EDT for planned maintenance. The monitor was returned to service at 1420 EDT after the completion of maintenance.

The licensee notified the NRC Resident Inspector, the Connecticut Department of Energy and Environmental Protection, and Waterford city of this event.

NON-LICENSED CONTRACT SUPERVISOR TESTED POSITIVE FOR ALCOHOL ON A RANDOM FITNESS-FOR-DUTY TEST

A non-licensed contract supervisor tested positive for alcohol on a random fitness for duty test. The supervisor's access to the facility has been terminated. The licensee has notified the NRC Resident Inspectors.

DISCOVERY OF AN AFTER-THE-FACT UNUSUAL EVENT

"This is a one hour report for the discovery of a condition that briefly met the emergency action level (EAL) for an Unusual Event but did not warrant declaration of an emergency classification. A detailed review of the conditions that existed during a thunderstorm that took place today revealed that the backup 50 meter wind speed briefly indicated 95.5 mph, which exceeds the HU 1.3 criteria of 95 mph. The primary 50 meter wind speed indicator did not exceed 89 mph. Operators in the control room did not observe wind speed exceed 80 mph on SPDS. This event is a one hour report based on the guidance in NUREG-1022 for a condition that met an emergency plan EAL and the basis for the emergency classification no longer existed at the time of discovery."

The NRC Resident Inspector has been informed.

UNANALYZED CONDITION THAT COULD HAVE RESULTED IN AN INCREASED MAXIMUM FLOOD LEVEL

"On June 27, 2014, TVA identified in a reanalyzed hydrologic analysis for Sequoyah Nuclear Plant (SQN) a deviation from the current hydrologic analysis. The flooding analysis in Section 2.4.3 of the SQN UFSAR assumes that the Watts Bar West Saddle Dike fails completely and instantaneously at approximately 1.5 feet of overtopping during a Peak Maximum Flood [PMF]. This assumption exists in the original design basis analysis and the revised analysis which supports SQN-TS-12-02, "Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis".

"The results of recent studies of the West Saddle Dike, conducted as part of the Fukushima Order 2.1 flooding review, indicate that the complete and instantaneous failure of the Watts Bar West Saddle Dike may not be a valid assumption. If the dike does not fail, analyses performed using the codes and methods consistent with those used in original plant design show that the east floodwall of the Watts Bar Dam would overtop. As a result of this overtopping, the east floodwall is assumed to fail. Based on this assumption and analysis, failure of the east floodwall of the Watts Bar Dam would result in an increase in the flood level at the SQN Plant Site. The current licensing basis PMF level for SQN is 719.6 feet as stated in Section 2.4.2.2 of the SQN UFSAR. In addition, it should be noted that by letter dated August 10, 2012, as supplemented by letters dated April 5, 2013 and January 16, 2014, TVA proposed a revised PMF level of 722.0 feet. Introducing non failure of the Watts Bar West Saddle Dike indicated a potential increase of approximately 1.5 feet over the revised PMF level.

"TVA performed additional analysis using current industry standard for flooding analysis. Specifically, TVA modeled the condition using the United States Army Corps of Engineers Hydrologic Engineering Center River Analysis System (HEC-RAS) tool. TVA's analysis of the condition using HEC-RAS determined that all required safety equipment for SQN would not be impacted and are considered operable based on a Prompt Determination of Operability completed on June 30, 2014.

"This report addresses a condition as described in 10 CFR 50.72 (b)(3)(ii)(B). TVA is making this report consistent with the guidance of NUREG-1022 regarding the application of engineering judgment to the evaluation of reportability of an unanalyzed condition.

"The NRC Resident Inspector has been notified of this condition."

* * * RETRACTION AT 1441 EDT ON 8/21/2014 FROM MATT LEENERTS TO MARK ABRAMOVITZ * * *

"On June 30, 2014, SQN reported (Event 50244) that during a re-analysis conducted as part of the Fukushima Order 2.1 flooding review, a probable maximum flood (PMF) design assumption that the Watts Bar Dam west saddle dike fails completely and instantaneously at approximately 1.5 feet of overtopping, was determined to be a non-conservative flood model assumption (i.e., invalid). As a result, TVA postulated that Watts Bar Dam's east floodwall would fail, increasing the site flood level at Sequoyah Nuclear Plant (SQN) by 1.5 feet; a condition that was beyond the current licensing basis.

"Through subsequent analysis, TVA has demonstrated that although the west saddle dike may not completely and instantaneously fail during a PMF (as previously assumed), the consequential increase in reservoir levels does not result in a failure of the Watts Bar Dam east floodwall and would not result in an increase in the flood level at SQN.

"Therefore, the previously reported 10 CFR 50.72(b)(3)(ii)(B) event is being retracted.

"The NRC Resident Inspector has been informed of this event retraction."

Notified the R2DO (Hickey).

UNANALYZED CONDITION THAT COULD HAVE RESULTED IN AN INCREASED MAXIMUM FLOOD LEVEL

"On June 27, 2014, TVA identified in a reanalyzed hydrologic analysis for Watts Bar Nuclear Plant (WBN) a deviation from the current hydrologic analysis. The flooding analysis in Section 2.4.3 of the WBN UFSAR assumes that the Watts Bar West Saddle Dike fails completely and instantaneously at approximately 1.5 feet of overtopping during a Peak Maximum Flood [PMF]. This assumption exists in the original design basis analysis and the revised analysis which supports WBN-UFSAR-12-01 (Application to Revise Watts Bar Nuclear Plant Unit 1 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis).

"The results of recent studies of the West Saddle Dike, conducted as part of the Fukushima Order 2.1 flooding review, indicate that the complete and instantaneous failure of the Watts Bar West Saddle Dike may not be a valid assumption. If the dike does not fail, analyses performed using the codes and methods consistent with those used in original plant design show that the east floodwall of the Watts Bar Dam would overtop. As a result of this overtopping, the east floodwall is assumed to fail. Based on this assumption and analysis, failure of the east floodwall of the Watts Bar Dam would result in an increase in the flood level at the WBN Plant Site. The current licensing basis PMF level for WBN is 734.9 feet as stated in Section 2.4.3.5 of the WBN UFSAR. In addition, it should be noted that by letter dated July 19, 2012, TVA proposed a revised PMF level of 739.2 feet. Introducing non failure of the Watts Bar West Saddle Dike indicated a potential increase of approximately 1.7 feet over the revised PMF level.

"TVA performed additional analysis using current industry standard for flooding analysis. Specifically, TVA modeled the condition using the United States Army Corps of Engineers Hydrologic Engineering Center River Analysis System (HEC-RAS) tool. TVA's analysis of the condition using HEC-RAS determined that all required safety equipment for WBN would not be impacted and are considered operable based on a Prompt Determination of Operability completed on June 30, 2014.

"This report addresses a condition as described in 10 CFR 50.72 (b)(3)(ii)(B). TVA is making this report consistent with the guidance of NUREG-1022 regarding the application of engineering judgment to the evaluation of reportability of an unanalyzed condition.

"The NRC Resident Inspector has been notified of this condition."

* * * RETRACTION AT 1705 EDT ON 8/21/2014 FROM MATTHEW ROBERTSON TO MARK ABRAMOVITZ * * *

"On June 30, 2014, TVA reported (Event 50245) that during a re-analysis conducted as part of the Fukushima Order 2.1 flooding review, a probable maximum flood (PMF) design assumption that the Watts Bar Dam west saddle dike fails completely and instantaneously at approximately 1.5 feet of overtopping, was determined to be a non-conservative flood model assumption (i.e., invalid). As a result, TVA postulated that Watts Bar Dam's east floodwall would fail, increasing the site flood level at Watts Bar Nuclear Plant (WBN) by 1.7 feet; a condition that was beyond the current licensing basis.

"Through subsequent analysis, TVA has demonstrated that although the west saddle dike may not completely and instantaneously fail during a PMF (as previously assumed), the consequential increase in reservoir levels does not result in a failure of the Watts Bar Dam east floodwall and would not result in an increase in the flood level at WBN.

"Therefore, the previously reported 10 CFR 50.72(b)(3)(ii)(B) event is being retracted.

"The NRC resident Inspector has been informed of this event retraction."

Notified the R2DO (Hickey).

AUTO-START OF STANDBY DIESEL GENERATORS DUE TO A GRID DISTURBANCE

"This report is being made under 10CFR50.72(b)(3)(iv)(A), 'Any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section' due to an auto start of 'A' and 'B' Standby Diesel Generators. At 1913 CDT, a grid disturbance during a local thunderstorm caused a valid bus undervoltage condition that resulted in the auto start of both the 'A' and 'B' Standby Diesel Generators. The 'A' and 'B' Standby Diesel Generator supply breakers did not close onto their respective buses as they remained powered by their normal power supply, the 1X003 Startup Transformer, during and after the event. NextEra Duane Arnold personnel inspections revealed no issues with breakers in the switchyard. ITC (Iowa Transmission Company) reported a fault on a 161 Kv line in the NextEra Duane Arnold vicinity. Offsite power remained operable during and following the event.

"As designed the 'A' and 'B' Emergency Service Water systems auto started when the diesel generators auto started. The Emergency Service Water systems and both Standby Diesel Generators have been returned to standby/readiness condition. All ECCS [Emergency Core Cooling System] systems were available before the event and have remained available following the event."

The licensee notified the NRC Resident Inspector.