05000483/FIN-2017001-01
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Finding | |
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| Title | Enforcement Action EA-17-050, Enforcement Discretion for Tornado-Generated Missile Protection Noncompliances |
| Description | Appendix A to 10 CFR Part 50, General Design Criteria for Nuclear Power Plants, Criterion 2, Design Bases for Protection Against Natural Phenomena, states, in part, that structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena, such as tornadoes. Criterion 4, Environmental and Dynamic Effects Design Basis, states, in part, that structures, systems and components important to safety shall be appropriately protected against dynamic effects including missiles which may result from events and conditions outside the nuclear power unit. As part of their response to Regulatory Issue Summary 2015-06, Tornado Missile Protection, the licensee performed a review of protection against tornado-generated missiles required by the current licensing basis. During the review, on March 13, 2017, the licensee identified a portion of the diesel generator fuel oil system that could be susceptible to tornado missiles. The licensee identified a low-probability scenario where one or more tornado-generated missiles could impact the emergency fuel oil truck connection lines on the south wall of the diesel generator building. The two non-safety-related connection lines are each connected to the safety-related normal fuel oil transfer lines via a tee connection and a normally closed isolation valve. Direct impact by a tornado-generated missile parallel to either trains connection line could impart a load on the tee connection to the normal fuel oil line that had not been evaluated. Failure of the tee connection would result in the associated diesel generator being incapable of performing its safety function. Relevant Enforcement Discretion Policy On June 10, 2015, the NRC issued Enforcement Guidance Memorandum (EGM) 15-002, Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance (Adams Accession Number ML15111A269). The EGM referenced a bounding generic risk analysis performed by the NRC staff that concluded that tornado missile vulnerabilities pose a low risk significance to operating nuclear plants. Because of this, the EGM described the conditions under which the NRC staff may exercise enforcement discretion for noncompliance with the current licensing basis for tornado-generated missile protection. Specifically, if the licensee could not meet the technical specification required actions within the required completion time, the EGM allows the staff to exercise enforcement discretion provided the licensee implements initial compensatory measures prior to the expiration of the time allowed by the limiting condition for operation. The compensatory actions should provide additional protection such that the likelihood of tornado missile effects are lessened. The EGM then requires the licensee to implement more comprehensive compensatory measures within 60 days of issue discovery. The compensatory measures must remain in place until permanent repairs are completed, or until the NRC dispositions the non-compliance in accordance with a method acceptable to the NRC such that discretion is no longer needed. In addition, the issue must be entered into the licensees corrective action program. Because EGM 15-002 listed Callaway as a Group A plant, enforcement discretion will expire on June 10, 2018. Because the EGM did not provide for enforcement discretion for any related underlying technical violations; any associated underlying technical violations will be assessed through the enforcement process. Licensee Actions The licensee declared both diesel generators inoperable, complied with the applicable technical specification action statements, initiated a condition report, invoked the enforcement discretion guidance, implemented prompt compensatory measures, and returned the systems, structures, and components to an operable status. The licensee instituted compensatory measures intended to reduce the likelihood of tornado missile effects. These included verifying that guidance was in place for severe weather procedures, abnormal and emergency operating procedures, and procedures dedicated to the Diverse and Flexible Coping Strategy (FLEX), that training on these procedures was current, and that a heightened level of awareness of the vulnerability was established. As an additional compensatory measure, the licensee placed concrete blocks adjacent to the piping penetrations to provide a greater level of protection from tornado generated missiles. NRC Actions The inspectors review addressed the material issues in the plant, and whether the measures were implemented in accordance with the guidance in EGM 15-002. The inspectors also evaluated whether the measures as implemented would function as intended and were properly controlled. The inspectors verified through inspection that the EGM 15-002 criteria were met in each case. Therefore, the staff determined that it was appropriate to exercise enforcement discretion and not take enforcement action for the required actions of Technical Specification 3.8.1, AC Sources Operating, provided the non-compliances are resolved by June 10, 2018 (EA-17-050). The inspectors did not fully review the underlying circumstances that resulted in the technical specification violations. As stated in EGM 15-002, violations of other requirements which may have contributed to the technical specification violations will be evaluated independently of EGM implementation. The inspectors will verify restoration of compliance and assess the underlying circumstances during future inspection activities. |
| Site: | Callaway  |
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| Report | IR 05000483/2017001 Section 1R15 |
| Date counted | Mar 31, 2017 (2017Q1) |
| Type: | Violation: Severity level Enforcement Discretion |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | D Proulx E Simpson E Uribe J O 'Donnell L Carson M Langelier M Phalen M Stafford N Greene R Kumana T Hartma |
| Violation of: | 10 CFR 50 Appendix A GDC 4 |
| INPO aspect | |
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Finding - Callaway - IR 05000483/2017001 | |||||||||||||||
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Finding List (Callaway) @ 2017Q1
Self-Identified List (Callaway)
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