Event Notification Report for November 15, 2005

REPORTABLE INCIDENT DUE TO DEVIATION FROM TECHNICAL SPECIFICATION REQUIREMENTS

"At 1216 CST, on 11-15-05 the C-333, Unit 4, Cell 8, Process Gas Leak Detection (PGLD) system was declared inoperable by the Plant Shift Superintendent (PSS) in order to perform maintenance. Due to the inoperability of the system, a [Technical Specification Requirement] TSR required continuous smoke watch was put into place according to LCO 2.4.4.1. At 1330 CST a Tornado Warning was issued by the National Weather Service (NWS) for the area affecting the plant and surrounding area that remained in affect until 1400 CST. Based on the NWS warning, radar indications, and visual observations from on-site spotters, the PSS ordered the activation of the plants Take Cover Signal and [Public Address] PA announcements were made instructing the plant population to shelter in their designated 'take cover areas'. Upon activation of the Take Cover Signal, the individual performing the TSR required smoke watch at C-333, Unit 4, Cell 8, discontinued the smoke watch and reported to the 'take cover area' as required by plant emergency procedures. At this time, the PSS entered TSR 1.6.4, 'Conditions Outside TSR' due to discontinuing the TSR required smoke watch. TSR 1.6.4 requires that in an emergency, if a situation develops that is not addressed by the TSR, operations personnel should use their training and expertise to take actions to correct or mitigate the situation. In compliance with the TSR, the PSS instructed the Cascade Coordinator to reduce the operating pressure in the area affected by the Unit 4, Cell 8, PGLD outage, which would place the equipment in a non-applicable TSR mode of operation. Operating pressures were being reduced when the National Weather Service lifted the Tornado Warning at 1400 CST. At this time, the PSS lifted the Take Cover order and the TSR required smoke watch was put back into place at Unit 4, Cell 8 at 1405 CST. At this time the plant came into compliance with TSR LCO 2.4.4.1 and exited TSR 1.6.4.

"This event is being reported under the requirements of TSR 1.6.4, 'If emergency action is taken, both a verbal and written notification shall be made in accordance with 10 CFR 76.120'."

The NRC Senior Resident Inspector has been notified of this event.

INVALID PRIMARY CONTAINMENT ISOLATION SYSTEM (PCIS) ACTUATION

"This 60-day telephone notification is being made under reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) to describe an invalid actuation of general containment isolation signals affecting more than one system.

"On November 15, 2005, while operating at 100% thermal power, at 08:05 hours CST, Browns Ferry Unit 2 incurred an inadvertent, invalid actuation of the PCIS Group 6 logic. One reactor zone ventilation exhaust radiation monitor (the B channel) was indicating downscale due to a pre-existing maintenance issue, and, during activities to formally place the channel in a tripped status in accordance with the applicable Technical Specifications, the PCIS logic fuse for the opposite (A channel) radiation monitor was inadvertently removed rather than the fuse for the B channel. The PCIS logic responded as designed to the condition of both radiation monitors being downscale, and a Group 6 logic actuation resulted. The actuation was invalid because it resulted from an error related to an equipment tagging activity; there were no actual plant conditions which required the associated equipment actuations/isolations to occur.

"The following equipment actuations/isolations occurred: Unit 2 Group 6
* Initiation of the Standby Gas Treatment System
* Initiation of Control Room Emergency Ventilation
* Isolation of the following equipment:
* reactor zone and refuel zone normal ventilation systems
* drywell-torus differential pressure compressor
* drywell-torus Hydrogen/Oxygen analyzers
* drywell radiation continuous air particulate monitor

"All equipment responded in accordance with the plant design. There were no safety consequences or impacts on the health and safety of the public. The event was entered into TVA's corrective action program for resolution."


The NRC senior resident inspector has been notified.

PART 21 NOTIFICATION - SAFETY LIMIT MINIMUM CRITICAL POWER RATIO CALCULATION

"(i) Name and address of the individual informing the Commission:
Jerald S. Holm, Framatome ANP, 2101 Horn Rapids Road, Richland, WA 99354

"(ii) Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect:
The Safety Limit Minimum Critical Power Ratio (SLMCPR) for Susquehanna Unit 1 Cycle 14.

"(iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect:
Framatome ANP

"(iv) Nature of the defect or failure to comply and the safety hazard which is created or could be created by such a defect or failure to comply:
The mean bow and standard deviation from recent channel measurements during a Susquehanna Unit 1 Cycle 14 (SQ1C14) mid-cycle outage exceed the values in the current database used in licensing analyses for Susquehanna Unit 1.

"The majority of data acquired at Susquehanna Unit 1 during the mid-cycle outage were in the exposure range of 35 to 45 MWd/kgU. In that range, the new measurements exceed both the mean and the standard deviation of bow from the existing database. Preliminary results from the measurements indicate that the mean from the new data is approximately 60% higher and the standard deviation is approximately 50% higher.

"The SLMCPR Technical Specification limit for Susquehanna Unit 1 Cycle 14 was too low (by about .01) when calculated with the channel bow values from the Framatome ANP channel bow database, since channel bows measured for Cycle 14 exceeded those in the channel bow database. Therefore a safety limit could have been violated.

"(v) The date on which the information of such a defect or failure to comply was obtained:
This issue was determined to be a deviation on November 15, 2005.

"(vi) In the case of a basic component which fails to comply, the number and the location of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulations in this part:
Susquehanna Unit 1 Cycle 14.

"The other plants supported by Framatome ANP analyses, or using Framatome ANP supplied channels, are not impacted.

"(vii) The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for this action; and the length of time that has been or will be taken to complete the action:
A new SLMCPR for the remainder of the Susquehanna Unit 1 Cycle 14 (denoted Cycle 14a) operation has been provided by Framatome ANP which bounds channel bow experienced during Susquehanna Unit 1 Cycle 14.

"Susquehanna Unit 1 also applied a conservative interim CPR penalty (.04) during Cycle 14 operation when slow settling of the control blades was encountered.

"(viii) Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees:
In order to assure that other plants are not impacted in the future by unanticipated channel bow, recommended surveillance actions will be provided in January 2006 to all customers using Framatome ANP channels.