05000293/LER-2017-002

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LER-2017-002, Isolation of HPCI
Event date: 03-27-2017
Report date: 05-25-2017
Reporting criterion: 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
2932017002R00 - NRC Website
LER 17-002-00 for Pilgrim Regarding Isolation of HPCI
ML17163A179
Person / Time
Site: Pilgrim Entergy icon.png
Issue date: 05/25/2017
From: Perkins E P
Entergy Nuclear Operations
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML17163A179 (6)


comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

Pilgrim Nuclear Power Station 05000- 293 2017 - 00 - 002

BACKGROUND

The High Pressure Coolant Injection (HPCI) System is provided to ensure that the reactor core is adequately cooled to limit fuel clad temperature in the event of a small break in the nuclear system and loss of coolant which does not result in rapid depressurization of the reactor vessel. The HPCI System permits the reactor to be shut down while maintaining sufficient reactor vessel water inventory until the reactor vessel is depressurized. HPCI continues to operate until reactor vessel pressure is below the pressure at which Low Pressure Coolant Injection or Core Spray systems would maintain core cooling.

EVENT DESCRIPTION

On March 27, 2017, at 1825 [EDT], with the reactor at 100 percent core thermal power and steady state conditions, the HPCI System was declared inoperable and Technical Specifications (TS) Limiting Condition for Operation (LCO) Action Statement (AS) 3.5.C.2 was entered. Pilgrim Nuclear Power Station (PNPS) personnel were performing planned testing of the Reactor Core Isolation Cooling (RCIC) System per TS Table 4.2.B.

During the test, it has been determined that plant personnel heated the wrong temperature switch causing the HPCI system to isolate.

CAUSE OF THE EVENT

The Direct Cause of the event was the application of heat to a HPCI temperature switch. The system responded as designed and the HPCI primary containment isolation valves closed making HPCI unavailable.

The Root Cause of this event is two Nuclear Controls Technicians decided to deviate from procedure requirements while performing procedure 8.M.2-2.6.3 Attachment 1, RCIC Steam Line High Temperature Instrument Functional Test.

CORRECTIVE ACTIONS

The corrective action to preclude repetition documents that both individuals' qualifications have been removed and their site access restricted.

Specific disciplinary actions have been taken with the individuals involved pursuant to the requirements of 10 CFR 73.56(c).

comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

2017 - 00

SAFETY CONSEQUENCES

There are no consequences to the general safety of the public, nuclear safety, industrial safety and radiological safety from this event. The isolation of HPCI has been evaluated and it has been determined that the individuals involved were not following procedure requirements for performing testing. The loss of safety function created by isolating the HPCI System lasted for only thirty three minutes during this evolution.

No additional actions to reduce the consequence are necessary.

REPORTABILITY

This report is submitted in accordance with 10 CFR 50.73(a)(2)(v)(D), any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.

PREVIOUS EVENTS

A review of Pilgrim Station License Event Reports (LERs) for the past 10 years was performed. The focus of the review was LERs that involved loss of HPCI system function. The following LERs were reviewed:

These LER events do not identify any similar failure mechanisms to that described in this LER.

REFERENCES:

CR-PNP-2017-2622 - 002