05000446/FIN-2015003-03
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Finding | |
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| Description | Unit 2 Train B Safety Injection System Inoperable for Longer Than Allowed by Technical Specifications and Notice of Enforcement Discretion 15-4-02 Introduction. The inspectors opened an unresolved item associated with a potential noncompliance with Technical Specification 3.5.2 that occurred on July 10, 2015. Notice of Enforcement Discretion 15-4-02 was granted by the NRC staff agreeing not to enforce compliance with the technical specification completion time for an additional 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />. On July 7, 2015, a potential through wall leak from pipe segment SI-2-070 in the Unit 2, train B Safety Injection (SI) pump room was discovered during routine system walkdowns by a licensee engineer. Approximately 1-2 cups of boric acid accumulation was identified on the floor underneath valve 2SI-0055 (SIP 2-02 Suction Test Connection). The pipe insulation was removed to identify the source of the leakage, which was determined to be from a socket weld connection between the six inch suction piping for SI Pump 2-02 and the 34 inch vent piping to 2SI-0055. At 1:04 p.m. on July 7, 2015, the licensee declared unit 2, train B, Emergency Core Cooling System (ECCS) inoperable and entered Technical Specification 3.5.2, Condition B, for one or more [ECCS] trains inoperable for reasons other than one inoperable centrifugal charging pump, and at least 100 percent of the ECCS flow equivalent to a single operable ECCS train available. Required Action B.1 of Technical Specification 3.5.2 required restoration of the train(s) to an operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Further, Technical Specification 3.5.2 required that if Required Action B.1 could not be met within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, unit 2 would be required to enter Technical Specification 3.5.2 Condition C, Required Actions C.1 and C.2, and be in Mode 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 4 in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The licensees initial assessment determined the likely cause of the socket weld failure to be vibration induced fatigue failure. An attempted repair utilizing ASME Code Case N-666 was conducted on July 8, 2015. During the welding activity a small pinhole leak A-16 developed in the vent piping. The licensee then initiated alternate repair activities including a freeze seal on the affected piping, installation of a new vent line and valve (to facilitate post-repair filling and venting of the SI piping), and repair of the affected weld. The licensee requested a notice of enforcement discretion and an additional 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> to restore safety injection pump 2-02, such that the completion time of Required Action B.1 would expire at 2:04 p.m. on July 11, 2015. A notice of enforcement discretion was granted by the NRC staff at 9:20 a.m. on July 10, 2015. Consistent with NRC policy, the NRC agreed not to enforce compliance with the specific technical specifications in this instance, but will further review the cause(s) that created the apparent need for enforcement discretion to determine if there is a performance deficiency, if the issue is more than minor, or if there is a violation of requirements. This issue will be tracked as an unresolved item. (URI 05000446/2015003-03, Notice of Enforcement Discretion 15-4-02 for One Inoperable Train of Emergency Core Cooling Systems) |
| Site: | Comanche Peak  |
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| Report | IR 05000446/2015003 Section 4OA3 |
| Date counted | Sep 30, 2015 (2015Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | J Drake J Groom J Josey J Reynoso R Kumanab Dionneg Guerra J Groom J Josey J O'Donnell J Watkins L Carson M Bloodgood P Hernandez R Kumana S Hedger |
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Finding - Comanche Peak - IR 05000446/2015003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Comanche Peak) @ 2015Q3
Self-Identified List (Comanche Peak)
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