Semantic search

Jump to navigation Jump to search
 Entered dateEvent description
ENS 406393 April 2004 14:10:00

This is an 8-hour notification being made to report that a valid ESF Auxiliary Feed actuation occurred. Salem Unit 1 is in mode 5 with RHR providing shutdown cooling. '11' Aux Feed Pump was in service to fill '13' and '14' steam generators for wet lay-up conditions. Actual levels were low in both '13' and '14' steam generators but jumpers were installed on steam generator narrow range level channel III and IV to prevent an ESF actuation. On 4/03/04 at 1050 AM, a breaker effecting reactor protection system channel III was cleared and tagged as part of preparations to remove 1C 4KV vital bus from service. The actual low level in '13' and '14' steam generators along with the power loss to channel III caused 2 out of 3 logic to be satisfied and initiated an AFW actuation. '11' Auxiliary Feed Pump remained running. '12' Auxiliary Feed Pump auto started. '13' Auxiliary Feedwater Pump was removed from service prior to the actuation and did not start. The '13' and '14' steam generators continued to fill. '11' and '12" Auxiliary Feed Valves (11AF21 and 12AF21) were closed and no level rise was observed. The breaker was restored and reactor protection system channel III was placed back in service. All auto start signals cleared after power was restored and the '12' Aux Feed Pump was stopped at 1101. There were no unusual or unexpected plant response from the actuation. All safety systems and equipment performed as expected. Entry into mode 6 is expected this afternoon and progress of the refueling outage is expected to continue. There were no personnel injured. The licensee will inform the Lower Alloways Creek Township (LAC) and has informed the NRC Resident Inspector.

  • * * RETRACTION ON 05/05/04 AT 1252 EDT FROM S. SAUER TO A. COSTA * * *

On April 3, 2004 at 1410 PSEG made an 8 hour notification to report a valid ESF actuation of the auxiliary feedwater system (Event Number 40639). At the time of the report 11 Auxiliary feedwater pump was in service to fill the 13 and 14 steam generators for wet lay-up. The levels on those generators were low (as previous plant condition had demanded) and the jumpers had been installed in the level detectors to prevent the automatic start of the auxiliary feedwater pumps. 12 auxiliary feedwater pump was out of service. The steam driven auxiliary feedwater pump was tagged out of service. Core heat removal was being provided by the Residual Heat Removal System. On April 3, with the steam generator level being carried below the low level setpoint, in accordance with procedures, as a result of other activities associated with the refueling outage the installed jumpers were removed causing the auto start of the 12 pump. Subsequent investigation Into this event and further review of NUREG 1022 has determined that the condition described above is not reportable under the requirements of 10CFR50.72(b)(3)(iv) or 50.73(a)(2)(iv). As stated In NUREG 1022 the intent of reporting under this paragraph is '..to report actuations of systems that mitigate the consequences of significant events .. The Staff does not consider this to include single component actuation because single components of complex systems, by themselves usually do not mitigate the consequences of significant events.' Furthermore valid signals are defined as ' those signals that are Initiated in response to actual plant conditions .. Satisfying the requirements for initiation of a safety function of the system.' (emphasis added on safety function). In this particular event the required Safety Function to maintain the core cooled and decay heat removal was being accomplished by the Residual Heat Removal System and it remained unaffected throughout this event. The plant was in a condition where the steam generators in conjunction with the Auxiliary Feedwater System were not part of the ultimate heat sink or a principal means to remove decay heat. The Auxiliary Feedwater System was only functional and available to provide a means to place the steam generators in wet lay-up in support of outage activities. The 11 pump was already in service providing for this non-safety related function. Thus the auto start of the 12 pump was not as a result of a valid signal for a significant event that required initiation of a mitigating function; e.g. an ESF actuation. Therefore this event was not reportable under 10CFR50.72 or 50.73, as per the guidance provided in NUREG 1022. The licensee notified the NRC Resident Inspector. Notified R1DO(Della Greca).