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| Start date | Title | Description | Topic | |
|---|---|---|---|---|
| ENS 54018 | 22 April 2019 15:30:00 | En Revision Imported Date 5/1/2019 | EN Revision Text: CONTRACT SUPERVISOR TESTED POSITIVE ON A RANDOM FITNESS-FOR-DUTY TEST A contract supervisor tested positive for drugs on a random fitness-for-duty test. The contractor's access to the facility has been revoked and his badge was confiscated. Additionally, the supervisor failed a follow-up test administered the previous day (see EN #54017).
On April 16, 2019, an individual was selected for a follow-up drug test. The same individual was selected again on April 17, 2019 for a random drug test. The results for both tests were ruled by the Medical Review Officer (MRO) on the same day and ruled positive for the same drug on April 22, 2019. These FFD violations were reported to the NRC on April 22, 2019, as EN #54017 and EN #54018, respectively. As allowed by 10 CFR 26.185(o), the MRO further reviewed the quantitation of the drug in both tests and determined that no further drug use had occurred since the first positive test. Therefore, the MRO concluded that this should be considered one FFD violation, and EN #54018 is being retracted. No changes are needed to EN #54017. The NRC Resident Inspector has been notified of this retraction. Notified R2DO (Heisserer) and FFD Group (email). | |
| ENS 43564 | 13 August 2007 19:22:00 | Potential Hot Short Issue with Containment Spray Sump Suction Valves | A condition is being reported as a conservative measure regarding a situation involving potential fire induced circuit failures on associated circuits. Plant Vogtle is considered to be in compliance with its current fire protection licensing basis, Branch Technical Position CMEB 9.5.1 as endorsed by UFSAR Appendix 9B, however, this condition is being reported as the generic industry issues associated with multiple spurious circuit failures have not been resolved to date. A potential hot short issue exists involving Containment Spray Sump Suction valves 1(2)HV-9002A, 1(2)HV- 9003A, 1(2)HV-9002B, and 1(2)HV-9003B. If a fire were to occur in a location where the control circuit cables for those valves run in the same electrical raceway, a credible condition exists where either flowpath could spuriously open which would cause the Refueling Water Storage Tank (RWST) to drain down to the containment sumps. The fire zones where associated cables are located were placed under a compensatory hourly fire watch until compensatory measures were established. As an interim corrective action, operator manual actions have been specified and incorporated into plant procedures to deenergize and verify closed one valve in the series flowpath upon determination that a credible fire exists. These manual actions are in accordance with RIS 2006-10 for plants which are licensed to operate after January 1, 1979. Southern Nuclear will determine long term corrective actions for this condition. The effects of a fire sufficient to cause a spurious operation of multiple valves is not expected to be immediate and thus will allow sufficient time to perform the manual actions. The licensee notified the NRC Resident Inspector.
An eight hour report (EN#43564) per 10CFR50.72(b)(3)(ii)(B) was conservatively reported based on a fire-induced hot short issue (multiple-spurious) which could result in the spurious opening of Containment Spray Sump Suction valves 1(2)HV-9002A, 1(2)HV-9003A, 1(2)HV-9002B, and 1(2)HV-9003B. HV-9002 and HV-9003 are two valves in series between the containment emergency sump and the containment spray pumps. If a fire were to occur in a location where the control circuit cables for those valves run in the same electrical raceway, it is postulated a condition may exist where either flowpath could spuriously open which would cause the Refueling Water Storage Tank (RWST) to drain down to the containment sumps. The VEGP design basis defines a spurious control signal action/inaction as being caused by a single hot short, open circuit, or short-to-ground for a single component. Since all three conditions are postulated, the assumption that all adverse conditions will happen to the subject component(s) yields a conservative evaluation. Where a hi/low pressure interlace (fire-induced LOCA) is involved, an unlimited number of spurious control signal actions/inactions are postulated. Calculations have been reviewed to ensure these design criteria have been met. At this time, there is no definitive new guidance (Generic Letter, etc.) by the NRC on how licensees are to handle analysis of multiple spurious shorts. The status and history of misunderstanding and confusion relative to the regulatory and design requirements is well documented in NRC EGM 98-002 Rev. 2 and EGM 07- 004. The NRC staff and the industry are currently working to resolve questions raised by the industry about the adequacy of the existing staff guidance concerning fire-induced circuit failures and the consistency of staff interpretations of both the guidance and the underlying regulatory requirements. In summary, VEGP is in conformance with the current design basis. However, as defense-in-depth, actions have been taken that include implementation of hourly fire watches in the affected zones until procedural guidance for performance of manual actions were added to the Annunciator Response Procedures for the Fire Alarm Computer. The manual actions consist of opening the breakers for one of the emergency sump-to containment spray pumps suction isolation valves and then verifying the valves are closed. Based on the above discussion, SNC is retracting EN#43564. The licensee will notify the NRC Resident Inspector. Notified R2DO (Ogle). | Hot Short Operator Manual Action Hourly Fire Watch |
| ENS 42942 | 28 October 2006 16:23:00 | Specified System Actuation | During plant cooldown/depressurization in Mode 3, an Over Temperature (OT) Delta Temperature reactor trip signal was generated. The reactor Trip Breakers opened as designed (all rods were previously inserted). Additionally, a low Tavg/P-4 Feedwater Isolation Signal was generated and all Bypass Feedwater Regulation Valves closed (open for long-cycle recirculation operation). No Feedwater Isolation Valves were open at the time. All systems performed as designed. Actual loop Delta T's (Th - Tc) never exceeded 3.3 degrees F, well below the calculated OT Delta T setpoint. But plant Delta T calculations are based on narrow range Th and Tc instruments with scaling to low limits. When actual plant temperature was lowered to the lower limits of each instrument, calculated Delta T increased to the OT Delta T setpoint causing the reactor trip signal. Existing procedure guidance did not adequately ensure that the reactor trip breakers are open prior to initiating a partial plant cooldown. The plant was stabilized. The long-cycle recirculation was re-established and plant cooldown/depressurization was recommenced, as originally planned to 340 degrees F and 925 psig. The licensee notified the NRC Resident Inspector.
Alvin W. Vogtle, Unit 1, Operating License no. NPF-68, Event Notification #42942 is retracted. The event reported in the notification which occurred during the Unit 1 cooldown in Mode 3 was not representative of the conditions under which the Over Temperature Delta Temperature (OTDT) setpoint is intended to operate. The setpoint is intended to provide protection while the reactor is in Modes 1 and 2. As the cooldown progressed from Normal Operating Pressure and Temperature (NOPT), eventually the Reactor Coolant System (RCS) hot and cold leg temperature indications reached the low end of their ranges or scales. Further reductions of temperature resulted in artificial indications of core power (delta-T) that cannot be relied upon as a valid input to the OTDT protective function. The actuation of the Reactor Protection System (RPS) is not considered to be a valid actuation. As such, this is not reportable under 10 CFR 50.72(b)(3)(iv)(A). The Unit 1 Feedwater Isolation caused from the OTDT reactor trip is not a function is listed in 10 CFR 50.72(b) (3)(iv)(B) as a system whose actuation is required to be reported under 10 CFR 50.72(b)(3)(iv)(A). The licensee notified the NRC Resident Inspector. |