ML051240085

Technical Specification Pages Amendments 223 & 218, Allowing for Replacement of Existing Batteries

ML051240085
Person / Time
Site:	Catawba
Issue date:	04/27/2005
From:	Sean Peters NRC/NRR/DLPM/LPD2
To:	Jamil D Duke Energy Corp
Peters S, NRR/DLPM, 415-1842
References
TAC MC3823, TAC MC3824
Download: ML051240085 (18)

Text

DC Sources - Operating 3.8.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. A and/or D channel of D.1 Enter applicable Immediately DC electrical power Condition(s) and Required subsystem inoperable. Action(s) of LCO 3.8.9, "Distribution Systems-AND Operating", for the associated train of DC Associated train of DG electrical power distribution DC electrical power subsystem made subsystem inoperable. inoperable.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify DC channel and DG battery terminal voltage is 7 days

> 125 V on float charge.

SR 3.8.4.2 Verify DG nickel cadmium battery cell voltage > 1.36 V 7 days I on float charge.

SR 3.8.4.3 Verify no visible corrosion at the DC channel and DG 92 days battery terminals and connectors.

OR (For the DC channel and DG batteries utilizing lead acid cells only) Verify battery connection resistance of these I items is < 1.5 E-4 ohm.

(continued)

Catawba Units 1 and 2 3.8.4-2 Amendment Nos. 223, 218

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.4 Verify DC channel and DG battery cells, cell plates, and 18 months racks show no visual indication of physical damage or abnormal deterioration that could degrade battery performance.

SR 3.8.4.5 Remove visible terminal corrosion, verify DC channel and 18 months DG battery cell to cell and terminal connections are clean and tight, and are coated with anti-corrosion material.

SR 3.8.4.6 Verify DC channel and DG lead acid battery connection 18 months I resistance is < 1.5 E4 ohm.

SR 3.8.4.7 Verify each DC channel battery charger supplies 18 months

> 200 amps and the DG battery charger supplies > 75 amps with each charger at > 125 V for > 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

SR 3.8.4.8 ----- NOTES

1. The modified performance discharge test in SR 3.8.4.9 may be performed in lieu of the service test in SR 3.8.4.8.

2. This Surveillance shall not be performed for the DG batteries in MODE 1, 2, 3, or 4.

Verify DC channel and DG battery capacity is adequate 18 months to supply, and maintain in OPERABLE status, the required emergency loads for the design duty cycle when subjected to a battery service test.

(continued)

Catawba Units 1 and 2 3.8.4-3 Amendment Nos. 223, 218

Battery Cell Parameters 3.8.6 3.8 ELECTRICAL POWER SYSTEMS 3.8.6 Battery Cell Parameters LCO 3.8.6 a. Battery cell parameters for the channels of DC batteries shall be within the limits of Table 3.8.6-1;

b. Battery cell parameters for the Diesel Generator (DG) Train A and Train B betteries utilizing lead acid cells shall be within the limits of Table 3.8.6-1; and

c. Battery cell parameters for the DG Train A and Train B batteries utilizing nickel cadmium cells shall be within the limits of temperature, level, and voltage.

APPLICABILITY: When associated DC electrical power subsystems are required to be OPERABLE.

Catawba Units 1 and 2 3.8.6-1 Amendment Nos.223, 218

Battery Cell Parameters 3.8.6 ACTIONS LItrT.C

" I t-- ----

Separate Condition entry is allowed for each battery.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or more batteries A.1 Verify pilot cells electrolyte 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (channel(s) of DC level and float voltage batteries, DG batteries meet Table 3.8.6-1 utilizing lead acid cells, Category C limits.

or both) with one or more battery cell AND parameters not within Category A or B limits. A.2 Verify battery cell 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> parameters meet Table 3.8.6-1 Category C AND limits.

Once per 7 days thereafter AND A.3 Restore battery cell 31 days parameters to Category A and B limits of Table 3.8.6-1.

(continued)

Catawba Units 1 and 2 3.8.6-2 Amendment Nos. 223, 218

Battery Cell Parameters 3.8.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and B.1 Declare associated battery Immediately associated Completion inoperable.

Time of Condition A not met. AND OR B.2 ----- NOTE-------

Only applicable for One or more batteries inoperable DG batteries.

(channel(s) of DC batteries, DG batteries, or both) with average Enter applicable Immediately electrolyte temperature Condition(s) and Required of the representative Action(s) of LCO 3.8.1, cells < 600 F. 'AC Sources - Operating",

or LCO 3.8.2, "AC Sources OR - Shutdown" for the associated DG made One or more batteries inoperable.

(channel(s) of DC batteries, DG batteries utilizing lead acid cells, or both) with one or more battery cell parameters not within Category C values.

C. One or more DG C.1 Enter applicable Immediately batteries utilizing nickel Condition(s) and Required cadmium cells with Action(s) of LCO 3.8.1, electrolyte level not at or "AC Sources - Operating",

above the low mark and or LCO 3.8.2, "AC Sources not at or below the high - Shutdown" for the mark. associated DG made inoperable.

OR One or more DG batteries utilizing nickel cadmium cells with two or more connected cells

< 1.36 V.

Catawba Units I and 2 3.8.6-3 Amendment Nos. 223, 218

Battery Cell Parameters 3.8.6 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6.1 Verify battery cell parameters of the channels of DC and 7 days DG batteries utilizing lead acid cells meet Table 3.8.6-1 Category A limits.

SR 3.8.6.2 Verify electrolyte level of DG batteries utilizing nickel 7 days cadmium cells is at or above low mark and at or below high mark.

SR 3.8.6.3 Verify battery cell parameters of the channels of DC and 92 days DG batteries utilizing lead acid cells meet Table 3.8.6-1 Category B limits. AND I

Once within 7 days after a battery discharge

< 110V AND Once within 7 days after a battery overcharge

> 150V SR 3.8.6.4 Verify average electrolyte temperature for the channels 92 days of DC and DG batteries of representative cells is > 60 0F.

Catawba Units 1 and 2 3.8.6-4 Amendment Nos. 223, 218

Battery Cell Parameters 3.8.6 Table 3.8.6-1 (page 1 of 1)

Battery Cell Parameters Requirements CATEGORY A: CATEGORY C:

LIMITS FOR EACH CATEGORY B: ALLOWABLE DESIGNATED LIMITS FOR EACH LIMITS FOR EACH PARAMETER PILOT CELL CONNECTED CELL CONNECTED CELL Electrolyte Level > Minimum level > Minimum level Above top of plates, indication mark, and indication mark, and and not overflowing

<% inch above < % inch above maximum level maximum level indication mark(a) indication mark(a)

Float Voltage > 2.13 V > 2.13 V > 2.07 V Specific Gravity(b)(c) > 1.200 > 1.195 Not more than 0.020 below average of all AND connected cells or

> 1.195 Average of all connected cells AND

> 1.205 Average of all connected cells

> 1.195 (a) It is acceptable for the electrolyte level to temporarily increase above the specified maximum during equalizing charges provided it is not overflowing.

(b) Corrected for electrolyte temperature and level. Level correction is not required, however, when battery charging is c 2 amps when on float charge.

(c) A battery charging current of < 2 amps when on float charge is acceptable for meeting specific gravity limits following a battery recharge, for a maximum of 7 days. When charging current is used to satisfy specific gravity requirements, specific gravity of each connected cell shall be measured prior to expiration of the 7 day allowance.

Catawba Units 1 and 2 3.8.6-5 Amendment Nos.223, 218

DC Sources-Operating B 3.8.4 BASES ACTIONS (continued) the loss of the channel DC power and the associated DG DC power, the load center power for the train is inoperable and the Condition(s) and Required Action(s) for the Distribution Systems must be entered immediately.

SURVEILLANCE SR 3.8.4.1 REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps to ensure the effectiveness of the charging system and the ability of the batteries to perform their intended function. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery (or battery cell) and maintain the battery (or a battery cell) in a fully charged state. The voltage requirements are based on the nominal design voltage of the battery and are consistent with the initial voltages assumed in the battery sizing calculations. The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).

SR 3.8.4.2 Verifying battery individual cell voltage while on float charge for the DG batteries utilizing nickel cadmium cells ensures each cell is capable of supporting their intended function. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery (or battery cell) and maintain the battery (or a battery cell) in a fully charged state. The battery cell voltage limit of >

1.36 V is consistent with the nominal design voltage of the battery and is based on the manufacturer's recommended minimum float charge voltage for a fully charged cell with adequate capacity. The battery is designed and sized with a capacity margin sufficient t6 allow up-to one cell to be fully degraded with a voltage < 1.36 V assuming that no cells are jumpered out. The battery sizing calculations account for a degraded cell by assuming the degraded cell undergoes a worst-case polarity reversal during a design discharge. For this surveillance, a minimum of two cells shall be tested every seven days. The cells selected for testing shall be rotated on a monthly basis. The 7 day Frequency is consistent with the manufacturer's recommendations.

Catawba Units 1 and 2 B 3.8.4-5 Revision No. 3

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE REQUIREMENTS (continued) -

SR 3.8.4.3 For the DC channel and DG batteries utilizing lead acid cells, visual inspection to detect corrosion of the battery terminals and connections, or measurement of the resistance of each intercell, interrack, intertier, and terminal connection, provides an indication of physical damage or abnormal deterioration that could potentially degrade battery performance. The presence of visible corrosion does not necessarily represent a failure of this SR, provided an evaluation determines that the visible corrosion does not affect the OPERABILITY of the battery.

For the DG batteries utilizing nickel cadmium cells, visual inspection to detect corrosion of the battery terminals and connections provides an indication of physical damage or abnormal deterioration that could potentially degrade battery performance. The presence of visible corrosion does not necessarily represent a failure of this SR, provided an evaluation determines that the visible corrosion does not affect the OPERABILITY of the battery.

The Surveillance Frequency for these inspections, which can detect conditions that can cause power losses due to resistance heating, is 92 days. This Frequency is considered acceptable based on operating experience related to detecting corrosion trends.

SR 3.8.4.4 For the DC channel batteries, visual inspection of the battery cells, cell plates, and battery racks provides an indication of physical damage or abnormal deterioration that could potentially degrade battery performance. The presence of physical damage or deterioration does not necessarily represent a failure of this SR, provided an evaluation determines that the physical damage or deterioration does not affect the OPERABILITY of the battery (its ability to perform its design function).

For the DG batteries, visual inspection of the battery cells, cell plates, and battery racks provides an indication of physical damage or abnormal deterioration that could potentially degrade battery performance. Since the DG nickel cadmium battery cell jars are not transparent, a direct visual inspection of the cell plates cannot be performed. Instead, the cell plates are inspected for physical damage and abnormal deterioration by:

1) visually inspecting the jar sides of each cell for excessive bowing and/or deformation, and 2) visually inspecting the electrolyte of each cell for abnormal appearance.

Catawba Units I and 2 B 3.8.4-6 Revision No. 4

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE REQUIREMENTS (continued)

Operating experience has shown that these components usually pass the SR when performed at the 18 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

SR 3.8.4.5 and SR 3.8.4.6 Visual inspection and resistance measurements of intercell, interrack, intertier, and terminal connections provide an indication of physical damage or abnormal deterioration that could indicate degraded battery condition. The anticorrosion material, as recommended by the manufacturer for the batteries, is used to help ensure good electrical connections and to reduce terminal deterioration. The visual inspection for corrosion is not intended to require removal of and inspection under each terminal connection. The removal of visible corrosion is a preventive maintenance SR. The presence of visible corrosion does not necessarily represent a failure of this SR provided visible corrosion is removed during performance of SR 3.8.4.5.

For the DG batteries utilizing nickel cadmium cells, the cell-to-cell terminal pole screws should be set from 14 to 15 foot-pounds of torque.

Operating experience has shown that these components usually pass the SR when performed at the 18 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

SR 3.8.4.7 This SR requires that each battery charger for the DC channel be capable of supplying at least 200 amps and at least 75 amps for the DG chargers. All chargers shall be tested at a voltage of at least 125 V for 2 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. These requirements are based on the design capacity of the chargers (Ref. 4). According to Regulatory Guide 1.32 (Ref. 10), the battery charger supply is required to be based on the largest combined demands of the various steady state loads and the charging capacity to restore the battery from the design minimum charge state to the fully charged state, irrespective of the status of the unit during these demand occurrences. The minimum required amperes and duration ensures that these requirements can be satisfied.

The Surveillance Frequency is acceptable, given the unit conditions required to perform the test and the other administrative controls existing to ensure adequate charger performance during these 18 month intervals. In addition, this Frequency is intended to be consistent with expected fuel cycle lengths.

Catawba Units 1 and 2 B 3.8.4-7 Revision No. 7

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.8.4.8 A battery service test is a special test of battery capability, as found, to satisfy the design requirements (battery duty cycle) of the DC electrical power system. The discharge rate and test length should correspond to the design duty cycle requirements as specified in Reference 4. The DC channel batteries are tested to supply a current > 522.14 amps for the first minute, then > 267.71 amps for the next 9 minutes, > 376.15 amps for the next 10 minutes, and > 281.94 amps for the next 100 minutes.

Terminal voltage is required to remain > 110.4 volts during this test. The DG batteries utilizing nickel cadmium cells are tested to supply a current

Ž 218.5 amps for the first minute, then Ž 42.5 amps for the next 10 minutes, then > 121.8 amps for the next minute, then > 42.5 amps for the remaining 108 minutes. Terminal voltage is required to remain 2 105 volts during this test. The DG batteries utilizing lead acid cells are tested to supply a current > 228.0 amps for the first minute, then > 37.75 amps for the next 10 minutes, then > 127.1 amps for the next minute, then >

37.75 amps for the remaining 108 minutes. Terminal voltage is required to remain > 105 volts during this test.

Except for performing SR 3.8.4.8 for the DC channel batteries with the unit on line, the Surveillance Frequency of 18 months is consistent with the recommendations of Regulatory Guide 1.32 (Ref. 10), which states that the battery service test should be performed during refueling operations or at some other outage, with intervals between tests, not to exceed 18 months.

This SR is modified by two Notes. Note 1 allows the performance of a modified performance discharge test in lieu of a service test.

The modified performance discharge test is a performance discharge test that is augmented to include the high-rate, short duration discharge loads (during the first minute and 11-to-12 minute discharge periods) of the service test. The duty cycle of the modified performance test must fully envelope the duty cycle of the service test if the modified performance discharge test is to be used in lieu of the service test. Since the ampere-hours removed by the high-rate, short duration discharge periods of the service test represents a very small portion of the battery capacity, the test rate can be changed to that for the modified performance discharge test without compromising the results of the performance discharge test.

The battery terminal voltage for the modified performance discharge test should remain above the minimum battery terminal voltage specified in the battery service test for the duration of time equal to that of the service test.

Catawba Units 1 and 2 B 3.8.4-8 Revision No. 5

Battery Cell Parameters B 3.8.6 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.6 Battery Cell Parameters BASES BACKGROUND This LCO delineates the limits on electrolyte temperature, level, float voltage, and specific gravity for the channels of DC power source I batteries. The LCO also addresses the trains of DC for the Diesel Generator battery limits for both lead acid and nickel cadmium cells. A I discussion of these batteries and their OPERABILITY requirements is provided in the Bases for LCO 3.8.4, "DC Sources-Operating," and LCO 3.8.5, "DC Sources-Shutdown."

APPLICABLE The initial conditions of Design Basis Accident (DBA) and transient SAFETY ANALYSES analyses in the UFSAR, Chapter 6 (Ref. 1) and Chapter 15 (Ref. 2),

assume Engineered Safety Feature systems are OPERABLE. The DC electrical power system provides normal and emergency DC electrical power for the diesel generators, emergency auxiliaries, and control and switching during all MODES of operation.

The OPERABILITY of the DC subsystems is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the unit. This includes maintaining at least one train of DC sources OPERABLE during accident conditions, in the event of:

a. An assumed loss of all offsite AC power or all onsite AC power, and

b. A worst case single failure.

Battery cell parameters satisfy Criterion 3 of 10 CFR 50.36 (Ref. 3).

LCO Battery cell parameters must remain within acceptable limits to ensure availability of the required DC power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence or a postulated DBA. Electrolyte limits are conservatively established, allowing continued DC electrical system function even with Category A and B limits not met.

Catawba Units I and 2 B 3.8.6-1 Revision No. 2

Battery Cell Parameters B 3.8.6 BASES APPLICABILITY The battery cell parameters are required solely for the support of the associated DC electrical power subsystems. Therefore, battery electrolyte is only required when the DC power source is required to be OPERABLE. Refer to the Applicability discussion in Bases for LCO 3.8.4 and LCO 3.8.5.

ACTIONS A.1, A.2. and A.3 With one or more cells in one or more batteries (DC batteries, DG batteries utilizing lead acid cells, or both) not within limits (i.e., Category A limits not met, Category B limits not met, or Category A and B limits not met) but within the Category C limits specified in Table 3.8.6-1 in the accompanying LCO, the battery is degraded but there is still sufficient capacity to perform the intended function. Therefore, the affected battery is not required to be considered inoperable solely as a result of Category A or B limits not met and operation is permitted for a limited period.

The pilot cell electrolyte level and float voltage are required to be verified to meet the Category C limits within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (Required Action A.1). This check will provide a quick indication of the status of the remainder of the battery cells. One hour provides time to inspect the electrolyte level and to confirm the float voltage of the pilot cells. One hour is considered a reasonable amount of time to perform the required verification.

Verification that the Category C limits are met (Required Action A.2) provides assurance that during the time needed to restore the parameters to the Category A and B limits, the battery is still capable of performing its intended function. A period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is allowed to complete the initial verification because specific gravity measurements must be obtained for each connected cell. Taking into consideration both the time required to perform the required verification and the assurance that the battery cell parameters are not severely degraded, this time is considered reasonable. The verification is repeated at 7 day intervals until the parameters are restored to Category A or B limits. This periodic verification is consistent with the normal Frequency of pilot cell Surveillances.

Continued operation is only permitted for 31 days before battery cell parameters must be restored to within Category A and B limits. With the consideration that, while battery capacity is degraded, sufficient capacity exists to perform the intended function and to allow time to fully restore the battery cell parameters to normal limits, this time is acceptable prior to declaring the battery inoperable.

Catawba Units 1 and 2 B 3.8.6-2 Revision No. 1

Battery Cell Parameters B 3.8.6 BASES ACTIONS (continued) ,

B.1 and B.2 With one or more batteries (DC batteries, DG batteries utilizing lead acid cells, or both) with one or more battery cell parameters outside the Category C limit for any connected cell, sufficient capacity to supply the maximum expected load requirement is not assured and the corresponding DC electrical power subsystem must be declared inoperable. Additionally, other potentially extreme conditions, such as not completing the Required Actions of Condition A within the required Completion Time or average electrolyte temperature of representative cells (applicable to DC batteries and both types of DG batteries) falling below 60 0F, are also cause for immediately declaring the associated DC electrical power subsystem inoperable per Required Action B.1.

In addition, Required Action B.2 mandates that the appropriate LCO(s) must then be entered for the DG supported by the inoperable DC subsystem. If the plant is in MODES 1 through 4, LCO 3.8.1, "AC Sources - Operating" is required to be entered. If the DG is required to support equipment during MODES 5 or 6 or movement of irradiated fuel assemblies, regardless of operating mode, LCO 3.8.2, "AC Sources -

Shutdown," is the appropriate LCO.

Required Action B.2 is modified by a Note indicating that it is only applicable for inoperable DG batteries.

C.1 With one or more DG batteries utilizing nickel cadmium cells with one or more battery cell(s) not within the limits of level, sufficient capacity to supply the required load for the DG is not assumed and the corresponding DC electrical power subsystem must be declared inoperable immediately. With one or more DG batteries utilizing nickel cadmium cells with two or more battery cells not within limits of voltage, sufficient capacity to supply the required load for the DG is not assumed and the corresponding DC electrical power subsystem must be declared inoperable immediately. Appropriate LCO(s) must then be entered for the DG supported by the inoperable DC subsystem. If the plant is in MODES 1 through 4, LCO 3.8.1, "AC Sources-Operating" is required to be entered.

If the DG is required to support equipment during MODES 5 or 6 or movement of irradiated fuel assemblies, regardless of operating mode, LCO 3.8.2, "AC Sources-Shutdown," is the appropriate LCO.

Catawba Units I and 2 B 3.8.6-3 Revision No. 2

Battery Cell Parameters B 3.8.6 BASES SURVEILLANCE SR 3.8.6.1 -

REQUIREMENTS This SR verifies that Category A battery cell parameters are consistent with IEEE-450 (Ref. 4), which recommends regular battery inspections (at least one per month) including voltage, specific gravity, and electrolyte temperature of pilot cells. This SR is applicable to both DC batteries and DG batteries utilizing lead acid cells.

SR 3.8.6.2 This SR verifies the DG nickel cadmium battery cell parameter of level via regular battery inspection (at least once every 7 days). The electrolyte level is monitored in order to maintain battery performance and effectiveness. The 7 day Frequency has been shown acceptable through operating experience.

SR 3.8.6.3 The quarterly inspection of the channels of DC and DG batteries utilizing l lead acid cells for specific gravity and voltage is consistent with IEEE-450 l (Ref. 4). In addition, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of a battery discharge < 110 V or a battery overcharge > 150 V, the battery must be demonstrated to meet Category B limits. Transients, such as motor starting transients, which may momentarily cause battery voltage to drop to < 110 V, do not constitute a battery discharge provided the battery terminal voltage and float current return to pre-transient values. This inspection is also consistent with IEEE-450 (Ref. 4), which recommends special inspections following a severe discharge or overcharge, to ensure that no significant degradation of the battery occurs as a consequence of such discharge or overcharge.

SR 3.8.6.4 This Surveillance verification that the average temperature of representative cells is 2 600F, is consistent with a recommendation of IEEE-450 (Ref. 4), that states that the temperature of electrolytes in representative cells should be determined on a quarterly basis.

Lower than normal temperatures act to inhibit or reduce battery capacity.

This SR ensures that the operating temperatures remain within an acceptable operating range. This limit is based on manufacturer recommendations.

Catawba Units 1 and 2 B 3.8.6-4 Revision No. 2

Battery Cell Parameters B 3.8.6 BASES SURVEILLANCE REQUIREMENTS (continued) -

The term "representative cells" replaces the fixed number of "six connected cells", consistent with the recommendations of IEEE-450 (Ref.

4) to provide a general guidance to the number of cells adequate to monitor the temperature of the battery cells as an indicator of satisfactory performance. For some cases, the number of cells may be less than six, in other conditions, the number may be more.

Table 3.8.6-1 This table delineates the limits on electrolyte level, float voltage, and specific gravity for three different categories. The meaning of each category is discussed below.

Category A defines the normal parameter limit for each designated pilot cell in each battery. The cells selected as pilot cells are those whose temperature, voltage, and electrolyte specific gravity approximate the state of charge of the entire battery.

The Category A limits specified for electrolyte level are based on manufacturer recommendations and are consistent with the guidance in IEEE-450 (Ref. 4), with the extra % inch allowance above the high water level indication for operating margin to account for temperatures and charge effects. In addition to this allowance, footnote a to Table 3.8.6-1 permits the electrolyte level to be above the specified maximum level during equalizing charge, provided it is not overflowing. These limits ensure that the plates suffer no physical damage, and that adequate electron transfer capability is maintained in the event of transient conditions. IEEE-450 (Ref. 4) recommends that electrolyte level readings should be made only after the battery has been at float charge for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

The Category A limit specified for float voltage is Ž 2.13 V per cell. This value is based on the recommendations of IEEE-450 (Ref. 4), which states that prolonged operation of cells < 2.13 V can reduce the life expectancy of cells. The Category A limit specified for specific gravity for each pilot cell is 2 1.200 (0.015 below the manufacturer fully charged nominal specific gravity or a battery charging current that had stabilized at a low value). This value is characteristic of a charged cell with adequate capacity. According to IEEE-450 (Ref. 4), the specific gravity readings are based on a temperature of 77 0F (250 C).

Catawba Units 1 and 2 B 3.8.6-5 Revision No. 1

Battery Cell Parameters B 3.8.6 BASES SURVEILLANCE REQUIREMENTS (continued)

The specific gravity readings are corrected for actual electrolyte temperature and level. For each 30F (1.67 0C) above 770F (250C), 1 point (0.001) is added to the reading; 1 point is subtracted for each 30 F below 770 F. The specific gravity of the electrolyte in a cell increases with a loss of water due to electrolysis or evaporation.

Category B defines the normal parameter limits for each connected cell.

The term "connected cell" excludes any battery cell that may be jumpered out.

The Category B limits specified for electrolyte level and float voltage are the same as those specified for Category A and have been discussed above. The Category B limit specified for specific gravity for each connected cell is > 1.195 (0.020 below the manufacturer fully charged, nominal specific gravity) with the average of all connected cells Ž 1.205 (0.010 below the manufacturer fully charged, nominal specific gravity).

These values are based on manufacturer's recommendations. The minimum specific gravity value required for each cell ensures that the effects of a highly charged or newly installed cell will not mask overall degradation of the battery.

Category C defines the limits for each connected cell. These values, although reduced, provide assurance that sufficient capacity exists to perform the intended function and maintain a margin of safety. When any battery parameter is outside the Category C limits, the assurance of sufficient capacity described above no longer exists, and the battery must be declared inoperable.

The Category C limits specified for electrolyte level (above the top of the plates and not overflowing) ensure that the plates suffer no physical damage and maintain adequate electron transfer capability. The Category C limits for float voltage are based on IEEE-450 (Ref. 4), which states that a cell voltage of 2.07 V or below, under float conditions and not caused by elevated temperature of the cell, indicates internal cell problems and may require cell replacement.

The Category C limit of average specific gravity 2 1.195 is based on manufacturer recommendations (0.020 below the manufacturer recommended fully charged, nominal specific gravity). In addition to that limit, it is required that the specific gravity for each connected cell must be no less than 0.020 below the average of all connected cells. This limit ensures that the effect of a highly charged or new cell does not mask overall degradation of the battery.

Catawba Units 1 and 2 B 3.8.6-6 Revision No. I

Battery Cell Parameters B 3.8.6 BASES SURVEILLANCE REQUIREMENTS (continued)

The footnotes to Table 3.8.6-1 are applicable to Category A, B, and C specific gravity. Footnote (b) to Table 3.8.6-1 requires the above mentioned correction for electrolyte level and temperature, with the exception that level correction is not required when battery charging current is < 2 amps on float charge. This current provides, in general, an indication of overall battery condition.

Because of specific gravity gradients that are produced during the recharging process, delays of several days may occur while waiting for the specific gravity to stabilize. A stabilized charger current is an acceptable alternative to specific gravity measurement for determining the state of charge. This phenomenon is discussed in IEEE-450 (Ref. 4).

Footnote (c) to Table 3.8.6-1 allows the float charge current to be used as an alternate to specific gravity for up to 7 days following a battery recharge. Within 7 days, each connected cell's specific gravity must be measured to confirm the state of charge. Following a minor battery recharge (such as equalizing charge that does not follow a deep discharge) specific gravity gradients are not significant, and confirming measurements may be made in less than 7 days.

The value of 2 amps used in footnote (b) and (c) is the nominal value for float current established by the battery vendor as representing a fully charged battery with an allowance for overall battery condition.

REFERENCES 1. UFSAR, Chapter 6.

2. UFSAR, Chapter 15.

3. 10 CFR 50.36, Technical Specifications, (c)(2)(ii).

4. IEEE-450-1980.

Catawba Units 1 and 2 B 3.8.6-7 Revision No. 1