ML20217N295

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Rev 0 to 1-OM-17.2, Resetting Protective Device/Restoring Power
ML20217N295
Person / Time
Site: Millstone Dominion icon.png
Issue date: 08/22/1997
From: Latz D
NORTHEAST NUCLEAR ENERGY CO.
To:
Shared Package
ML20217N155 List:
References
1-OM-17.2, NUDOCS 9708260100
Download: ML20217N295 (4)
v • d • e


Text

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3' 1-0M 17.2, Rov.0 Page 1 of 4 Millstone Unit One O OPERATIONS MANUAL SECTION 17.2

" RESETTING PROTECTIVE DEVICES / RESTORING POWER" Sponsor: D.R. Latz [/22h7 Effective Date TABLE OF CONTENTS PAGE NUMBER PURPOSE 00 1 2.0 GENERAL 2

2 3.0 RESETTINGIREPLACING PROTECTIVE DEVICES 2 4.0 RESTORING POWER TO A BUS / PANEL 3 5.0 RELAYS 4 6.0 REPORTING AND DOCUMENTING RELAY TARGETS 4 Approved by:

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MP1 Operations Manager O) t s

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1' 1-oM 17.2 Rev. 0 Pags 2 of 4 ,

1.0 - PURPOSE O)

L 1.1 To define Management expectations regarding identifying, reporting, documenting, and resetting protetive devices.

1.2 If a conflict exists between information in this OM Section and an approved procedure, the specific approved procedure shall take precedence.

2.0 GENERAL 2.1 A protective device is any one of the following:

1. Fuse
2. Relay -
3. Thermal circu.. breaker
4. Magnetic circo;t breaker S. Circuit breaker designed to " TRIP" due to protective relaying 2.2 Shift Management shall attempt to identify and isolate the cause of actuation prior to:

f-- 1. Fuse replacement, or

( 2. Re-closure of a circuit breaker, or

3. Closure of the alternate power supply circuit breaker, as applicable.

2.3:- Shift Management shall be notified prior to, and approve the following:

1. Replacing a blown fuse.
2. Resetting a relay target.
3. Rectosing a tripped circuit breaker.

- 2.4 When a protective device actuates, Shift Management shall review the affected equipment for operability.

3.0 RESETTINGlREPLACING PROTECTIVE DEVICES 3.1 IF the power source involves logic or ECCSIRPS components, Shift Management should assure a technical review, using prints, is performed to identify and/or-prevent inadvertent actuation's prior to resetting the device or replacing the fuse.

3.2 A 4160v breaker relay target shall not be reset until the breaker and its associated equipment have been inspected and/or relay activation dispositioned.

A- 3.3 Breakers that trip on magnetics shall not be reset and subsequent reclosure attempted without an appropriate investigation.

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, 1-OM-17.2, Rev. 0 Page 3 of 4 (l

V 3.4 Breakers which trip on thermals may be reset if the cause of the trip is thought to

_ be known and not in effect at the time of reset (e.g. a motor operated valve circuit breaker trips during the opening cycle and the cause is believed to be a hl0h differential pressure condition across the valve which has subsequently been corrected).

3.5 When a circuit breaker has tripped due to protective relaying and RESET is not performed prior to the end of the current shift, Shift Management shall ensure that this item is properly turned over.

3.6 If a protective device trips or blows fuses a second time, then additional closure or fuse replacement should not be attempted. Submit a TR and red tag to the Shift Manager until dispositioned.

3.7 in the event an electrical fault trip lockout should occur to equipment, the .j equipment should not be restarted (via reset of 86 lockout relay) until a detailed j investigation has been performed by NUSCO Generation Test and a review by A

~

Engineering.

3.8 Shift Management shall ensure that the actuation is documented and corrective actions initiated.

/m Q 4.0 - RESTORING POWER TO A BUS / PANEL 4.1 in the absence of an approved procedure the following guidelines should be applied prior to restoring power to a bus / panel.

NOTE: The re-energization of power to these circuits may cause equipment controlled by these circuits to operate as designed. For a particular circuit this could be for a

. pump to start or stop, for a valve to open or close, or for equipment to initiate or isolate.

4.2 Prior to re-energizing an electrical distribution bus or panel that unexpectedly de-energizes, Shift Management should: ,

1. Determine the cause of the trip.
2. Strip the bus of all of its loads.
3. Coordinate a controlled restoration of the associated loads IAW applicable procedure.

- 4.3 When restoring power tc a panel, Shift Management should ensure a technical review is performed on any associated Engineered Safeguard Feature (ESF) component or logic circuit to identify and/or prevent unplanned ESF actuation's.

NOTE: If control power is not available to an electrical bus, all automatic functions are disabled (i.e. overcurrert trips, LOCA starts, etc.) and a load shed will NOT occur on a subsequent loss of a bus.

1.OM-17 2. Rev_0 Page 4 of 4 9 4.4 If control power is not available to an electrical bus, Shift Management should determine if load breakers should be opened locally to strip the bus.

5.0 RELAYS 5.1 After a trip, each relay panel associated with the tripped equipment should be examined for activated relay targets.

5.2 Conventional protective relay targets are usually electromechanical devices which drop a red flag when the relay operates.

5.2.1 The targets (red flags) can be seen through the glass cover of the relays.

5.2.2 All relays with targets showing should be identified by the panel tag or by the relay nameplate (relay type, model, or style).

5.2.3 Any target unit designation such as "T" or " Time", "1" or " Inst.", and "Z" should also be identified.

5.2.4 If there are more than one relay of the same type, the relays with dropped h targets should be identified by " phase" or at least by their position on the panel.

5.3 Auxiliary relay targets are often operated by several protective relays with different functions.

5.3.1 The operation of all hand-reset lockout relays and of self-resetting auxiliary relays equipped with targets shall be identified.

5.3.2 The targets of the protective relays which operated the auxiliary tripping relay shall also be identified.

6.0 REPORTING AND DOCUMENTING RELAY TARGETS 6.1 Relay targets shall be reported to the applicable Shift Manager / Unit Supervisor and logged in the Narrative Log.

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