| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
08/01/2005 - 08/02/2005 ** EVENT NUMBERS ** |
 | !!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!! | | Power Reactor | Event Number: 41783 | Facility: PALO VERDE
Region: 4 State: AZ
Unit: [ ] [ ] [3]
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: DAN MARKS
HQ OPS Officer: JEFF ROTTON | Notification Date: 06/17/2005
Notification Time: 18:39 [ET]
Event Date: 06/17/2005
Event Time: 11:00 [MST]
Last Update Date: 08/01/2005 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(A) - DEGRADED CONDITION
21.21 - UNSPECIFIED PARAGRAPH
| Person (Organization):
JACK WHITTEN (R4)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 3 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown | Event Text POTENTIAL DEGRADED CONDITION DUE TO PRESSURIZER HEATER ELEMENT NON-CONFORMANCE
"The following event description is based on information currently available. If through subsequent reviews of this event, additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
"On June 15, 2005, Palo Verde Nuclear Generating Station was informed by Framatome that Thermocoax pressurizer heater elements provided for, and installed in Unit 3, were in non-conformance with specifications. Specifically, the active heating portion of the element was approximately 8 inches lower than design. The result of this error is that the active (heating) portion of the element extended into the nozzle area of the pressurizer heater sleeve and the heating effect on the pressurizer sleeve exceeded design, and possibly code-allowable temperature.
"Unit 3 operators entered Technical Requirements Manual LCO 3.4.103, Structural Integrity, Condition A for a ASME Code Class 1 component not conforming with requirements. The pressurizer can not be isolated and RCS temperature was already more than 50 degrees F above the minimum temperature required by NDT consideration when the condition was discovered. TLCO 3.0.100.3 is not applicable in Mode 5 and Technical Specification 3.4.9, Pressurizer, is not applicable in Mode 5. The RCS is in Mode 5 at approximately 190 degrees F and 350 psia.
"Engineering personnel are evaluating the code acceptability and potential for significant degradation resulting from the temperatures experienced by the pressurizer heater sleeves. On June 17, 2005, at approximately 11:00 AM MST, Palo Verde was informed that based on x-ray results of a PVNGS failed Thermocoax heater that revealed the active portion of the heater is longer than previously assumed, the metal temperatures exceeded ASME code allowable values. Stress levels are still under evaluation.
"This report is conservatively being placed per 10CFR50.72(b)(3)(ii)(A) based on the potential that the RCS pressure boundary may be seriously degraded, and 10CFR21(d)(3)(i) based on a defect in the pressurizer heater, a basic component, that may affect its safety function necessary to assure the integrity of the reactor coolant pressure boundary.
"An investigation of this condition will be conducted in accordance with the PVNGS corrective action program."
The Thermocoax heater elements were installed in November 2004, when all heaters in the Unit 3 pressurizer were replaced. Due to the increased failure rate all Thermocoax heater elements have been replaced in the last 30 days with General Electric style pressurizer heater elements that were used previously.
The heaters, which were also provided to SONGS 2&3 and Waterford 3, had a design variance (480 VAC single phase instead of 480 VAC 3-phase) which made them unique to Palo Verde. The impact of this variance is currently being evaluated.
The licensee notified the NRC Resident Inspector.
* * * UPDATE ON 8/1/05 AT 1143 EDT FROM R. BUZZARD TO P. SNYDER * * *
The licensee is retracting this event based on the following:
"This is a retraction of ENS 41783, placed with the Headquarter Operations Center on 06/17/2005 at 1839 EDT.
"On June 15, 2005, Palo Verde Nuclear Generating Station was informed by Framatome that the Thermocoax pressurizer heaters provided for, and installed in Unit 3, were in non-conformance with the applicable design specification. Specifically, the heating section of the heater was manufactured approximately 8 inches longer than cited in the specification. The result of this error was that the heating section extended into the pressurizer lower head.
"Engineering analysis concluded that the pressurizer lower head exceeded design and ASME Code allowable temperatures. This condition was reported on June 17, 2005 (ENS 41783).
"Further Engineering analysis concluded that the RCS pressure boundary (pressurizer lower head) was not significantly degraded. APS has requested NRC approval for a relief request (reference letter to the NRC dated June 19, 2005). The proposed alternative discussed in this relief request provided an acceptable level of quality and safety since no significant creep effects were introduced into the Unit 3 pressurizer lower head as a result of the design non-conformance. Therefore, APS has requested that the proposed alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(i). The NRC provided verbal approval for Unit 3 to continue operation.
"Based on the above information the "Degraded Operation" ENS notification made on June 17, is being retracted.
"The heater supplier, FRAMATOME ANP, INC, reported the defect in accordance with10CFR Part 21 on July 22, 2005 (ENS 41864)."
The licensee has retracted both the 10CFR Part 50.72(b)(3)(ii)(A) degraded condition notification and their 10 CFR Part 21 notification. Retraction of the 10 CFR Part 21 notification is based on the fact that the vendor reported the same condition.
The licensee notified the NRC Resident Inspector of the retraction. Notified R4DO (D. Powers). |
| Power Reactor | Event Number: 41885 | Facility: POINT BEACH
Region: 3 State: WI
Unit: [1] [2] [ ]
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: JAMES E. SCHLEIF
HQ OPS Officer: PETE SNYDER | Notification Date: 08/02/2005
Notification Time: 01:25 [ET]
Event Date: 08/01/2005
Event Time: 20:00 [CDT]
Last Update Date: 08/02/2005 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
| Person (Organization):
MONTE PHILLIPS (R3)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | Y | 100 | Power Operation | 100 | Power Operation | | 2 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text POTENTIALLY INOPERABLE SAFETY INJECTION PUMPS
"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 hour 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. | |