05000237/FIN-2018001-01
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Finding | |
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| Title | Enforcement Action: EA18016: Unanalyzed Condition for Tornado Missiles |
| Description | On June 10, 2015, the NRC issued Regulatory Issue Summary (RIS) 201506, Tornado Missile Protection (ML15020A419), focusing on the requirements regarding tornado generated missile protection and required compliance with the facility-specific licensing basis. The RIS also provided examples of noncompliance that had been identified through different mechanisms and referenced Enforcement Guidance Memorandum (EGM) 15002, Enforcement Discretion For Tornado Generated Missile Protection Non-Compliance, which was also issued on June 10, 2015 (ML15111A269) and revised on February 7, 2017 (ML16355A286). The discretion applied to Technical Specification (TS) limiting condition for operations (LCOs) that would require a reactor shutdown or mode change if the licensee could not meet the required actions within the TS completion time due to structures, system, and components (SSCs) declared inoperable because of tornado generated missile issues. The EGM stated that a bounding risk analysis performed for this issue concluded that tornado missile scenarios do not represent an immediate safety concern because their risk is within the LIC504, Integrated Risk-Informed Decision-Making Process for Emergent Issues, risk acceptance guidelines. In the case of Dresden Station, the EGM provided for enforcement discretion of up to three years from the original date of issuance of the EGM. The EGM allowed the licensee to re-establish operability when the licensee implemented, prior to the expiration of the time mandated by the affected LCOs, initial compensatory measures that provided additional protection such that the likelihood of tornado missile effects were lessened followed by more comprehensive compensatory measures within 60 days of issue discovery. The enforcement discretion was also conditional to the comprehensive measures remaining 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. Section 3.5 of the Dresden Power Station Updated Final Safety Analysis Report (UFSAR) states in part that SSCs important to safety shall be adequately protected against missiles generated by various causes, including natural phenomena. On February 12, 2018, the licensee initiated IR 04103159, identifying a nonconforming condition of Section 3.5. Specifically, the vent lines for the U2, U2/3, and U3 emergency diesel generator (EDG) fuel oil tanks were not adequately protected from tornado-generated missiles. The licensee declared fuel oil tanks and their associated EDGs inoperable, and promptly implemented compensatory measures designed to reduce the likelihood of tornado-generated missile effects. The condition was reported to the NRC as Event Notice (EN) 53204 as an unanalyzed condition and potential loss of safety function. Corrective Action(s): The licensee documented the inoperability of the SSCs in the Corrective Action Program (CAP) and in the control room operating log. In addition, the affected TS LCO conditions applicable in the mode of operation at the time of discovery were documented in the control room operating log. The shift manager notified the NRC resident inspector of implementation of EGM 15002, and documented the implementation of the compensatory measures to establish the SSCs operable but nonconforming prior to expiration of the LCO required action. The licensees immediate compensatory measures included: Verifying that procedures were in place and training was current for performing actions in response to a tornado event. Verifying that procedures were in place and training was current to respond to a tornado watch, such as: (1) actions to be taken relating to tornado missile hazards; (2) potential restoration of equipment important to maintaining safe shutdown conditions that is unavailable at the time of the tornado watch; (3) warning and protection strategies for personnel; and (4) damage assessment and restorative actions for equipment that may be damaged during a tornado. Establishing a heightened level of station awareness and preparedness relative to identified tornado missile vulnerabilities. The licensees longer term compensatory measure was to modify DOA001002, Tornado Warning Severe Winds procedure to include actions for damage assessment and restorative actions for systems with a vulnerability to damage from tornado missiles. Corrective Action Reference: IR 04103159 |
| Site: | Dresden  |
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| Report | IR 05000237/2018001 Section 1R15 |
| Date counted | Mar 31, 2018 (2018Q1) |
| Type: | URI: Severity level Enforcement Discretion |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | D Szwarc N Feliz-Adorno J Mancuso M Garza T Go C Phillips L Smith J Cameron |
| INPO aspect | |
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Finding - Dresden - IR 05000237/2018001 | |||||||||||||||||||||
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Finding List (Dresden) @ 2018Q1
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