Text

Proposed Tech Specs 4.8.2.3.2 Re Enforcement Discretion
	ML18100A563
Person / Time
Site:	Salem
Issue date:	08/24/1993
From:	; Public Service Enterprise Group
To:	;
Shared Package
ML18100A562	List: ML18100A561; ML18100A563;
References
	NUDOCS 9309010082
	Download: ML18100A563 (30)
	v • d • e

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NLR-N93142 ATTACHMENT A I.

TECHNICAL SPECIFICATION SURVEILLANCE REQUIREMENT 4.8.2.3.2 (B)

( 1)

APPLICABILITY: MODES 1,2,3,4 Surveillance requires that:

At least once per 92 days verify that the voltage of each connected cell is greater than or equal to 2.13 volts under float charge and has not decreased more*

than 0.27 volts from the value observed during the original acceptance test.

II.

SUMMARY

OF CURRENT SITUATION The specified quarterly surveillance was conducted on August 19, 1993.

At that time, one cell (no.47) of a sixty cell battery had a voltage below the required value of 2.13 volts.

The associated battery was declared inoperable and the appropriate Technical Specification Action Statement (TSAS) was entered.

The affected cell was placed on an individual charger (as specified in plant procedures) to restore cell voltage.

Approximately (4) hours later, the individual cell charger was removed and the cell was placed on float charge.

The cell voltage was verified greater than 2.13 volts and the TSAS was terminated.

PSE&G consulted the battery vendor (C&D) to discuss this situation.

The vendor concluded that one cell could have a degraded charge and recommended that we continue with the individual cell charge for a period of several days.

The individual cell charger was reinstalled and hourly cell voltage readings were taken.

Plant personnel continued to evaluate the cell and battery status with respect to Technical Specification operability.

Battery design capability with the remaining 59 cells was confirmed and documented in an Engineering Evaluation (Attachment B).

However, there was concern with Technical Specification compliance regarding the statement that all connected cells remain at or above 2.13 volts.

Jumpering out the degraded cell would have resolved the problem, however, this action requires disconnecting the entire battery from the bus/battery charger while completing the single cell jumpering.

During this period when the battery charger is supplying the DC bus without the normal battery load, a loss of battery charger or excessive output fluctuations (charger is not designed to operate independent of the battery) could result in a plant trip.

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9309010082 930824 PDR ADOCK 05000272 P

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fluctuations (charger is not designed to operate independent of the battery) could result in a plant trip.

A conference call was conducted on August 23, to discuss PSE&G actions and the possibility of requesting Enforcement Discretion should the individual cell voltage drop below 2.13 volts.

PSE&G had disconnected the individual cell charger and increased float voltage to 135 volts (allowable range is 132-135 volts).

This action was maintaining cell voltage above 2.13 volts while on the float charge.

Affected cell voltage readings were recorded through the night.

At 7:04 AM on August 24, the affected cell voltage dropped below the 2.13 volt limit and the associated TSAS was entered.

Since the arrival of the new replacement cell was imminent, jumpering the degraded cell could result in a plant trip, and compliance with the existing TSAS would require a plant shutdown, a decision was made to seek Enforcement Discretion.

PSE&G conducted a conference call with NRC Regional and NRR representatives to formally request Enforcement Discretion for a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period beginning at 9:04 AM on August 24, 1993.

III. JUSTIFICATION AND EVALUATION OF THE SAFETY SIGNIFICANCE AND POTENTIAL CONSEQUENCES OF THE REQUEST PSE&G evaluated whether the remaining 59 cells could meet the design limits of the 125 volt battery.

Assuming that the remaining lC 125 VDC battery cells meet the specific gravity and cell voltage requirements, with a normal float voltage of 2.13 volts per cell, 2.13 times 59 cells yields 125.67 volts which meets the Technical Specifications requirements for the overall battery.

The minimum voltage required at vital equipment terminals for a design basis 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months discharge rate is 105 volts.

When the full battery design (60 cells) is considered, 4 loads do not pass the 105 volt criteria.

These loads have been previously justified and accepted through Engineering Evaluations.

For a lC 125 VDC loading of 749 amps (0-1 minute) and 337 amps (1-120 minutes), the minimum battery terminal voltage at the end of the battery load cycle will be 1.88 volts per cell.

Therefore, voltage drop calculations were analyzed at 110.92 volts (l.88 volts per cell x 59 cells).

When 59 cells are considered, three additional loads fall below the 105 volt criteria.

Two of these loads are non-lE (500 KV circuit switcher 1T60 and the oscillograph).

The third load is the solenoids associated with 11 & 12 feedwater control and feedwater control bypass valves.

These feedwater solenoid valves are not required to be energized during an accident response.

l,

2.

fluctuations (charger is not designed to operate independent of the battery) could result in a plant trip.

A conference call was conducted on August 23, to discuss PSE&G actions and the possibility of requesting Enforcement Discretion should the individual cell voltage drop below 2.13 volts.

PSE&G had disconnected t~e individual cell charger and increased float voltage to 135 volts (allowable range is 132-135 volts).