ENS 41885
ENS Event | |
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01:00 Aug 2, 2005 | |
Title | Potentially Inoperable Safety Injection Pumps |
Event Description | As part of an ongoing calculation review project, design data is being evaluated on safety related motors. On 07/15/2005 at 2245, design data was accepted for 1P-15A Safety Injection motor. This data determined that during a design basis accident with degraded safeguards bus voltage, the 1P-15A Safety Injection Pump could trip and lockout on over current prior to the safeguards bus stripping on under voltage. The Safety Injection Pump lockout would then prevent an auto start of the Safety Injection Pump during Emergency Diesel Generator load sequencing. 1P-15A Safety Injection Pump was declared out of service at that time. No other safety related motors were affected by this data.
The 1P-15A Safety Injection Pump time over current set point was adjusted, based on the revised motor data, returning 1P-15A to service on July 17 at 2230. 2P-15A Safety Injection Pump time over current set point was also conservatively reset. On 08/01/2005 at 2000, additional design motor data was accepted, which impacted the time over current set point for 1P-15B and 2P-15B Safety lnjection motors. Review of this data determined that a similar potential exists that during a design basis accident with degraded safeguards bus voltage, 1P-15B or 2P-15B Safety Injection Pump could trip and lockout on over current prior to the respective safeguards bus stripping on under voltage. The Safety Injection Pump lockout would then prevent an auto start of the Safety Injection Pump during Emergency Diesel Generator load sequencing. 1P-15B and 2P-15B Safety Injection Pumps have been declared out of service as a result of accepting this new data. Based on the combined effect of all received design motor data, a condition existed prior to 07/15/2005, which could have impacted the design function of Unit 1 or Unit 2 Safety Injection Pumps during a design basis accident with degraded safeguards bus voltage. Both Unit 1 and both Unit 2 Safety Injection Pumps had the potential for this effect to prevent auto start on the Emergency Diesel Generator Loading Sequence per design. Therefore, this condition is being reported under 10 CFR 50.72(b)(3)(v)(D) due to the potential to prevent fulfillment of a safety function to mitigate an accident. Previous corrective action has been completed for Unit 1 and Unit 2 P-15A Safety Injection motors therefore, they remain Operable and capable of fulfilling design safety function. The licensee is currently in a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Tech. Spec. LCO 3.5.2 (A) action statement for ECCS train B on both Units. Repairs are expected to take six to eight hours. Safety Injection train A equipment is being protected by administrative requirements put in place by the licensee. Operations personnel have been briefed of the potential impacts. The licensee notified the NRC Resident Inspector. |
Where | |
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Point Beach Wisconsin (NRC Region 3) | |
Reporting | |
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
LER: | 05000266/LER-2005-003 05000266/LER-2005-004 |
Time - Person (Reporting Time:+0.42 h0.0175 days <br />0.0025 weeks <br />5.75316e-4 months <br />) | |
Opened: | James E. Schleif 01:25 Aug 2, 2005 |
NRC Officer: | Pete Snyder |
Last Updated: | Aug 2, 2005 |
41885 - NRC Website
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Unit 1 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
Unit 2 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |