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| Entered date | Event description | |
|---|---|---|
| ENS 52231 | 9 September 2016 20:01:00 | At 1739 (EDT) on Friday September 9, 2016 the Massachusetts Department of Environmental Protection and the Plymouth Massachusetts Fire Department were notified of a Hydrogen release in accordance with plant procedures and 310CMR40.300, Massachusetts Contingency Plan Notification for Oil and Hazardous Material; Identification and Listing of Oil and Hazardous Material, due to a release of hydrogen gas to the environment exceeding the reportable quantity of ten pounds. The Massachusetts DEP Tracking Number is RTN4-26311. The release was from the generator hydrogen cooling system. There was no plant damage. Hydrogen system pressure has been restored to the normal operating band with the Main Generator secured and is stable. The cause of the event is under investigation. This event posed no danger to the health and safety of plant personnel or members of the general public. The NRC Resident Inspector has been notified.
The Plymouth Massachusetts Fire Department was notified on Monday, September 12, 2016, at 1411 EDT. This clarifies information applicable to the local notification as identified in the original notification. Notified R1DO(Noggle) and NSIR (Stapleton) via email. |
| ENS 50771 | 27 January 2015 16:56:00 | On Tuesday, January 27, 2015, at 0948 EST, with the Reactor Mode Select Switch (RMSS) in the Shutdown position and Pilgrim Nuclear Power Station (PNPS) at 0% core thermal power, the High Pressure Coolant Injection (HPCI) system was isolated by the main control room operating crew and declared INOPERABLE. HPCI had been in service for reactor pressure control following the automatic reactor scram experienced during winter storm 'Juno' reported in EN# 50769. It appears there was a malfunction of the HPCI turbine gland seal condenser blower or associated condensate pump. Reactor pressure control was transitioned to the safety relief valves and the reactor cooldown was continued. The plant is stable. The Emergency Diesel Generators are powering the safety related 4KV buses and reactor water level is being maintained by the Reactor Core Isolation Cooling (RCIC) system. HPCI is required to be OPERABLE in accordance with Technical Specification 3.5.C.1. Since HPCI is a single train system, the INOPERABILITY is reportable in accordance with 10CFR50.72(b)(3)(v)(D). The cause of the HPCI malfunction is not known at this time and troubleshooting continues. This event had no impact on the health and/or safety of the public. The USNRC Senior Resident Inspector has been notified. Shutdown cooling is in service. |
| ENS 50356 | 12 August 2014 10:32:00 | At 0238 hours (EDT) on Tuesday, August 12, 2014, with Pilgrim Station at 100 percent power in the Run Mode with reactor coolant pressure at approximately 1025 psig and the High Pressure Coolant Injection (HPCI) System previously removed from service for maintenance, a condition with the potential to impact the operability of the HPCI System was discovered. The HPCI System was being operated in accordance with plant procedures to complete post maintenance test requirements. Upon HPCI initiation, the indicated flow on HPCI Flow Indicator FI-2340-1-1 was 0 Gallons Per Minute (GPM) with the flow controller in the manual mode. The indicated flow on HPCI Flow Indicator Fl-2340-1-1 remained at 0 GPM throughout the duration of the surveillance. Alternate flow indication indicated the expected HPCI flow rate. The flow controller in manual was capable of controlling at the demanded HPCI turbine speed. The HPCI turbine speed was manually varied with a corresponding change in the HPCI flow computer point reading. Activities to restore the flow indicator capability are in progress. The plant is in a safe condition and plant personnel are investigating the cause of the flow indicator issue. The NRC Resident Inspector has been informed of this notification. This notification is being made in accordance with 10 CFR 50.72(b)(3)(v)(B) and 10 CFR 50.72(b)(3)(v)(D). The licensee will be notifying the state.
Subsequent investigation determined that HPCI Flow Instrument SQRT-2340-10 output signal was 0 mA and did not change in response to the actual HPCI flow rate. With the SQRT-2340-10 output signal at 0 mA, the HPCI Flow controller would demand maximum HPCI injection flow in the AUTOMATIC control mode. Circuitry within the control system limits the maximum HPCI flow to 5250 GPM at a turbine speed of 4165 RPM. Engineering analysis has concluded that the HPCI pump operating limits (net positive suction head and low pressure suction trip) would not be exceeded in a maximum HPCI flow state. Therefore, the HPCI System was operable and capable of performing its residual heat removal and accident mitigation functions. Therefore, the initial 50.72(b)(3)(v)(B) and 10CFR50.72(b)(3)(v)(D) report is being retracted. The (NRC) Resident Inspector has been informed of this notification retraction. Notified the R1DO (Krohn). |
| ENS 49013 | 9 May 2013 00:51:00 | On May 8, 2013 at 1700 hours with the reactor in a Cold Shutdown condition and the Reactor Mode Select Switch in Refuel, the main control room annunciator system became inoperable during a preplanned activity to repair the associated 120VAC/125 VDC instrument power supply transfer switching scheme. The reactor cavity is flooded, the fuel pool gates are removed, shutdown cooling is in service and reactor vessel reassembly activities are in progress. The appropriate abnormal procedure was entered and compensatory actions including periodic monitoring of bus voltages and field annunciator panels were implemented for systems in service at the time of the loss. Station risk is green and all key safety functions are green. Troubleshooting is in progress however, return to service time has not been determined. This notification is being made in accordance with 10 CFR 50.72(b)(3)(xiii). The USNRC Resident Inspector has been notified. This event has no impact on the health and safety of the public. |
| ENS 48923 | 15 April 2013 02:01:00 | On Sunday, April 14, 2013 at 2217 hours, with the Pilgrim Nuclear Power Station (PNPS) Reactor Mode Select Switch (RMSS) in Start-up, the turbine generator previously removed from service, and the reactor sub-critical on Intermediate Range Monitors Range 2 and lowering, a manual reactor scram was inserted due to reactor pressure lowering beyond established control bands. At the time of the manual reactor scram PNPS was conducting a planned reactor shutdown to commence refueling outage (RFO) -19. All control rods fully inserted and Primary Containment Isolation System Group II (Reactor Building) and Group VI (Reactor Water Cleanup System) actuations occurred as designed due to the expected reactor water level shrink associated with the scram signal. All plant systems responded as designed. Off-site power was unaffected and was supplied by the start-up transformer (normal power supply for refuel and reactor shutdown operations). The Main Steam Isolation Valves (MSIV) were manually closed to terminate the reactor pressure reduction and the High Pressure Coolant Injection (HPCI) system was manually started in the reactor pressure control mode. The Reactor Protection System (RPS) was reset as were the reactor building and reactor water clean-up system isolation signals. Currently, the plant cooldown is continuing with the HPCI system in pressure control and reactor water level being maintained within normal bands with the condensate and feedwater system. The cause of the lowering reactor pressure has not been determined and remains under review. This event had no impact on the health and/or safety of the public. This 8-hour notification is being made in accordance with 10 CFR 50.72 (b)(3)(iv)(A). The NRC Senior Resident Inspector has been notified. The licensee will also be notifying state authorities. |
| ENS 48078 | 8 July 2012 17:50:00 | On July 8, 2012, at 1627 (EDT) hours and the reactor at 100% core thermal power, the following informational statement was issued by Entergy Nuclear regarding the status of the ongoing labor action at the site: UWUA Local 369 Pilgrim Station Workers Ratify New Contract. UWUA Local 369 Pilgrim Station union members voted today to ratify a new, four-year bargaining union contract which is effective May 16, 2012. 'The new contract, which came to fruition as a result of a lot of hard work on both sides, reflects our commitment to our employees, is acceptable to our union workers and preserves union interests,' said Pilgrim Site Vice President, Robert Smith. 'We look forward to our employees returning to work, which has been our goal throughout this process,' he continued. While specific details of the agreement are not being disclosed, the new four-year contract represents a substantial commitment to employees in the form of guaranteed wage increases, a comprehensive benefits package including premium health care plan options, a Company-matching 401(k) savings program, a defined benefits pension plan and a union incentive plan. 'We now turn our attention to the transition/turnover process and have initiated our Reintegration Plan which is a deliberate process to ensure the qualifications, training and other site requirements of returning employees are current and meet all NRC or procedural requirements. As employees are reintegrated, we will be phasing out our alternate staffing/contingency plan and expect to have all of our union employees back to work this week,' said Smith. The licensee notified the Massachusetts Emergency Management Agency and the NRC Resident Inspector. |
| ENS 46083 | 9 July 2010 15:55:00 | Entergy Pilgrim Station has twelve groundwater monitoring wells used to sample for tritium and other radioactive nuclides in accordance with the Nuclear Energy Institute's (NEI) voluntary Groundwater Protection Initiative (GPI). One of the wells, MW-205, located in the vicinity of the Condensate Storage Tanks (CST) indicated an elevated level of tritium, however well below the limits established by the NEI Groundwater Protection Initiative, the Nuclear Regulatory Commission's (NRC) limits for liquid effluent release and the Environmental Protection Agency's (EPA) limits for tritium in drinking or non-drinking water wells. The latest sample taken on June 21, 2010, returned a test result of 11,072 picocuries per liter of tritium. To date, tritium is the only isotope detected in the samples collected at the site. This information has been communicated to federal, state and local stakeholders and a press advisory is expected to be issued by the Massachusetts Department of Public Health (MDPH). On that basis and the anticipated interest to the general public this notification is being made. This event has no impact on the health and/or safety of the public. The NRC Resident Inspector is on-site and has been notified.
Entergy Pilgrim Station has received the results of its most recent weekly tritium sample taken on July 7, 2010 for groundwater monitoring well, MW-205. The sample results have shown an increase in the tritium concentration to 25,552 picocuries per liter (pCi/L) from the previous sample taken on June 30, 2010 which had a test result of 8,477 pCi/L. The latest results remain below any regulatory reporting requirements and the Environmental Protection Agency's (EPA) limits for tritium in non-drinking water wells. This information has been communicated to federal, state and local stakeholders. There remains no threat to drinking water sources and no impact on the health and/or safety of the public. The NRC Resident Inspector is on-site and has been notified of this update. This is an update to the 4-hour non-emergency notification made in accordance with 50.72(b)(2)(xi) on July 9, 2010 at 1555 hours. Notified R1DO (Doerflein). |
| ENS 44672 | 20 November 2008 21:21:00 | The High Pressure Coolant Injection (HPCI) system was declared inoperable on 11/20/08 at 1657 EST due to a Group 4 isolation signal generated during scheduled surveillance testing in accordance with PNPS (Pilgrim Nuclear Power Station) Procedure 8.M.2-2.5.3, Attachment 1. The HPCI testing was stopped to determine the cause of the isolation which was not part of the planned evolution. HPCI isolation was reset and HPCI was restored to standby lineup at 1804 EST. This event is an eight-hour notification. Efforts are ongoing to determine the cause of the error during testing. This event had no adverse effect to the health and/or safety of the public. The licensee has notified the NRC Resident Inspector of this event. This notification is being made in accordance with 10 CFR 50.72(b)(3)(v)(D) due to the loss of a single train system required to mitigate the consequences of an accident. |