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A past operability review determined that HVAC System Mechanical Water Chiller (X11X0001A) had been non-functional during the month of July 2013 due to a vulnerability with component operation resulting in a low oil level condition. The event impacts the operability requirements of the Chilled Water (VU) System and the area room coolers the system supports per TS 3/4.7.9, "Area Temperature Monitoring.

On September 25, 2013, XHX0001A tripped on low oil level following surveillance testing. The "Circuit 2 Low Oil Level" fault occurred due to the compressor oil level dropping below the low oil level indicator switch set point for 60 seconds which initiates shutdown of the component. The cause was low superheat, causing liquid floodback to the compressor and a low evaporator heat load that was insufficient to promote proper oil return in the evaporator. The chiller unit was intermittently operated as the only chiller on the "A" VU train in July 2013. Due to this vulnerable condition the non-functional chiller impacted the operability of the "A" train components served by the "A" train VU system.

On April 9, 2015, the station determined this event was reportable and is being submitted in accordance with 10 CFR 50.73(a)(2)(i)(B).

On December 2, 2009, during a review of the post-fire safe shutdown analysis, it was noted that conditions existed whereby the requirements of the Hope Creek (HC) fire protection program (BTP CMEB 9.5-1) for the required degree of separation for redundant safe shutdown trains were not met. Contrary to the Updated Final Safety Analysis Report (UFSAR) Section 9A, a postulated fire in either of the reactor building fire areas (RB1 or RB2) could have tripped, and prevented the start of both chilled water pumps, thus causing a loss of HVAC to several areas. The loss of the HVAC system is due to a logic system interrelationship that the post-fire safe shutdown analysis does not specifically address. This is a condition that has existed since the initial post-fire safe shutdown analysis was performed.

In accordance with the example provided in NUREG 1022 (Rev. 2), this event is reportable under 10CFR50.73(a)(2)(ii)(B) as an unanalyzed condition that significantly degraded plant safety. An 8-hour NRC ENS notification was made in accordance with 10CFR50.72(b)(3)(ii)(B) on 12/02/09 (event number 45536).

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At the time, HC was at 100% power. Carreotive actions were initiated to establish immediate compensatory - fire watches until the fire response procedures were revised. The post-fire safe shutdown analysis is being revised to identify the manual actions needed to address the logic interrelationships.

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On April 22, 2008, the CD481 1 E Safety Related Inverter Main Power input fuse failed. This failure combined with the `D' Emergency Diesel Generator being in a maintenance outage caused both trains of the Control Room Emergency Filtration (CREF) system to be INOPERABLE. This constituted an entry into Technical Specification (TS) 3.0.3. and a loss of the control room emergency filtration function in the event of a Loss of Offsite Power (LOOP).

An eight-hour notification was made for this event under the provisions of 10CFR50.72(b)(3)(v)(D).

A prompt investigation and an equipment apparent cause evaluation were conducted. The apparent cause of this event was a spurious misfire of Silicon Controlled Rectifiers (SCR's) in the inverter or static switch section. This caused a 1/2 cycle (or less) short circuit failure of the main input 600-amp DC fuse.

Corrective actions included replacing the blown fuse in CD-481 and checking the voltage output for stability before restoring to normal power.

On May 20, 2004, a Technical Specification Action Statement (TSAS) was entered due to degraded performance of the BK400 chiller, a component of the Control Room Emergency Filtration system (CREF). The TSAS was exited later the same day following repair of the chiller. Prior to May 20, 2004, the BK400 chiller had been out of service between May 9 and May 15 for maintenance. A portion of the maintenance activity was the replacement of the guide vane pivot arm. While trouble shooting the problem on May 20, 2004, it was discovered that the chiller guide vane pivot arm was slipping on the drive shaft. Based on this information, the BK400 chiller was determined to not have been capable of performing its design function when it was returned to service on May 15, 2004. Therefore, the BK400 chiller was inoperable from May 9 to May 20 which exceeds the 7 day allowed outage time of TS 3.7.2 Action a.

The cause of the slippage was determined to be setscrews that were not fully engaged. The immediate corrective action was to "dimple" the shaft and tighten the setscrews.

This event is being reported in accordance with 10CFR50.73 (a) (2) (i) (B).

On January 12, 2004, at 1015 hours during the performance of 18-month Technical Specification calibration of the 'C' channel Reactor Building Exhaust (RBE) radiation monitor, the 'A' channel RBE radiation monitor actuated resulting in an actuation of the Primary Containment Isolation System (PCIS). The actuation of PCIS caused the isolation of the Primary Containment Instrument Gas (PCIG) supply to the inboard Main Steam Isolation Valves (MSIVs). Prior to restoration of the PCIG system, the 'D' and 'B' inboard MSIVs began to drift closed. Anticipating the receipt of an automatic scram, the Reactor Operator (RO) manually scrammed the reactor by placing the mode switch to the shutdown position at 1048 hours. Shortly after the scram, the 'A' and 'C' MSIVs began to drift closed. At 1051, PCIG was restored and the inboard MSIVs returned to the open position. The inboard MSIVs never went fully closed which ensured that the main condenser remained available throughout the event for reactor heat removal. Following the manual scram, a low reactor water level scram signal was received (Level 3, +12.5 inches) as expected. At 2123 hours, a second invalid actuation of the PCIS occurred due to equipment related problems.

The cause of the PCIS actuation that led to the manual scram is attributed to a loose LEMO connector on the 'A' channel RBE radiation monitor that allowed intermittent contact when a nearby conduit was used as a hand hold to gain access to the 'C' channel RBE radiation monitor for surveillance testing. The apparent cause of the second invalid PCIS actuation is attributed to faulty Bailey cards associated with the RBE high radiation input to PCIS. The corrective actions associated with this event consist of procedure enhancements, emphasizing standards with maintenance personnel, re- evaluation of the scheduling of surveillance testing, and the repair/replacement of equipment.

This event is being reported in accordance with 10CFR50.73(a)(2)(iv)(A).

On January 21, 2004, while reviewing corrective action and maintenance records, it was determined that a violation of Technical Specification (TS) 3.7.2, Control Room Emergency Filtration system (CREF) (VI) had occurred. The discovery was based on conclusions reached regarding past maintenance activities and performance documentation. TS 3.7.2, requires that two independent CREF subsystems to be operable. With one subsystem inoperable the inoperable unit must be made operable within 7 days.

On September 10 and 11, 2003 maintenance was performed on the BK400 chiller due to erratic behavior of the chiller. The unit was placed back in service and continued to operate until September 19, 2003 at which time it was placed in standby due to system realignment. On October 2, the BK400 was required to start. Shortly following the call to start, the chiller tripped on low evaporator refrigerant pressure. Corrective maintenance performed on October 3, 2003 found that the float arm had become disengaged. The chiller was repaired and returned to service.

Operability screening conducted at that time did not identify the chiller as potentially inoperative for more than 7 days.

There were no safety consequences associated with this event because one CREF subsystem was operable at all times. Also, during the period of assumed inoperability of the subsystem there were no radiological releases which would have required operation of the standby CREF to protect personnel in the control room envelope.

This event is being reported in accordance with 10CFR50.73 (a) (2) (i) (B).