ML20205P643
| ML20205P643 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 04/09/1999 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20205P618 | List: |
| References | |
| PROC-990409, NUDOCS 9904200261 | |
| Download: ML20205P643 (11) | |
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Proposed Technical Requirement Manual Pages 9904200261 990409 PDR ADOCK 05000313 P PDR I
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TABLE OF CONTENTS l I
i USE AND APPLICATIONS I I
SECTION PAGE 1.0.1 Introduction.............................................................................. 1.0 1 1
1.0.2 TRMFormat.............................................................................. 1.0-1 )
1.0.3 Regulatory Status And Requirements............ ..... . . . . . . . . . . . . . . . . . . . 1.0-1 g 1.0.4 C h a n g e s To T h e TR M .. . ... . . . . .. . .. .. ... .. .. ... ... . . .. ..... . . . ........ .. ......... 1.0-2 1.0.5 N RC Reporting Of TRM Revisions....... . .. ... ....... .... ..... .. .......... 1.0-2 l t
1.0.6 TS A p plic a bility To Th e TR M ... ..................... ............... ..................... 1.0-2 LIMITING CONDITIONS FOR OPERATION 3.5 INSTRUMENTATION 3.5.1 Operational instrumentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5-1 J
3.7 AUXILIARY ELECTRICAL SYSTEMS i 3.7.1 S wit c h y a rd D C S o u rc e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7-1 3.7.2 Switchya rd Battery Cell Pa ra meters ..... .......................... .. ............. 3.7-2 SURVEILLANCE REQUIREMENTS 4.1 OPERATION AL IN STRU M ENTATION ITEM S ......................................... 4.1 -1 4.6 AUXILIARY ELECTRICAL SYSTEMS 4.6.1 Switc hya rd D C S o u rce s a n d B atte ries.............. ....... ......... ............. 4.6-1
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' l 3.7 AUXILIARY ELECTRICAL SYSTEMS LIMITING CONDITION FOR OPERATION 3.7.1 Switchyard DC Sources Applicability Applies to the auxiliary electrical power system.
Objectives To specify conditions of operation for the 125 VDC Switchyard Distribution System.
Requirements 3.7.1.1 At least 2 of 3 DC control power sources to the 125VDC switchyard distribution system shall be operable when the unit is above the cold shutdown condition.
3.7.1.2 With two control power sources from the plant to the switchyard inoperable, restore one control poNer source to operable status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
l 3.7.1.3 With two control power sources from the plant to the switchyard inoperable l and unable to satisfy the requirement of TRM 3.7.1.2, or with three control power sources from the plant to the switchyard inoperable, initiate a condition report to document the inoperability and determine any limitations for continued operation of the plant.
BASES The ANO switchyard consists of a 500 kV yard and a 161 kV yard connected by a 600 MVA autotransformer bank with a 22 kV tertiary winding. The control power for the 500 kV and 161 kV switchyard breakers can be supplied from three sources: 1) the 125 volt DC battery located in the switchyard control building; 2) the battery charger located in the switchyard control building; and 3) the ANO 1 DC bus "D41." The battery and battery charger operate in parallel continuously. The ANO-1 DC bus may be connected to the switchyard DC bus by a manual throwaver switch. The switchyard DC bus is a non-1E power supply and is described in the ANO-1 Safety Analysis Report (SAR)
Section 8.2.1.3.
References SAR, Section 8.2.1.3 ANO-1 TRM 3.7-1 Rev.1
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- l 3.7 AUXILIARY ELECTRICAL SYSTEMS LIMITING CONDITION FOR OPERATION 3.7.2 Switchyard Battery Cell Parameters Applicability l
Applies to the auxiliary electrical power system.
Objectives To specify conditions of operation for the 125VDC Switchyard Battery.
Requirements 3.7.2.1 Battery cell parameters shall be within limits when the DC control power sources to the 125VDC switchyard distribution system are required to be operable.
3.7.2.2 With one or more battery cell parameters not within TRM Table 4.6.1-1 Category A or B limits:
A. Within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, verify pilot cell electrolyte level and float voltage meet l TRM Table 4.6.1-1 Category C limits,
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B. Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and once per 7 days thereafter, verify battery cell parameters meet TRM Table 4.6.1-1 Category C limits, and C. Within 31 days, restore battery cell parameters to TRM Table 4.6.1-1 Category A and B limits.
3.7.2.3 With one or more battery cell parameters not within TRM Table 4.6.1-1 Category A or B limits and unable to satisfy the actions or allowable times of TRM 3.7.2.2.A,3.7.2.2.B, or 3.7.2.2.C, declare the battery inoperable and perform the required action of TRM 3.7.1.2 or TRM 3.7.1.3, as appropriate.
3.7.2.4 With battery electrolyte temperature of representative cells not within the limits of TRM 4.6.1.6, or with one or more battery cell parameters not within TRM Table 4.6.1-1 Category C limits, declare the battery inoperable and perform the required action of TRM 3.7.1.2 or TRM 3.7.1.3, as appropriate.
BASES Battery cell parameters must remain within acceptable limits to ensure availability of the required DC power. Cell parameter limits are conservatively established, allowing continued DC electrical system function even with TRM Table 4.6.1-1 Category A and B l limits not met.
l ANO-1 TRM 3.7 2 Rev. 1 l
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i With onn or more calls not within limits (i.e., TRM Tabla 4.6.1-1 Category A limits not mat, or Category B limits not met, or Category A and B limits not met) but within the TRM Table 4.6.1-1 Category C limits, the battery is degraded but still has sufficient capacity to perform its intended function. Therefore, the battery is not required to be considered inoperable solely as a result of Category A or B limits not met. The pilot cell electrolyte level and float voltage are required to be verified to meet the TRM Table 4.6.1-1 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 /> (TRM 3.7.2.2.A). These checks will provide a quick representative status of the remainder of the taattery cells. Verification that the TRM Table 4.6.1-1 Category C limits are met (TRM 3.7.2.2.8) providcs assurance that during the time needed to restore the parameters to within the Category A and B limits, the battery will still be capable of performing its intended function. This verification is repeated at 7 day intervals until the parameters are restored to within Category A and B limits. This periodic verification is consistent with the increased potential to exceed these battery parameter limits during these conditions.
With one or more battery cell parameters outside the TRM Table 4.6.1-1 Category C limit for any connected cell, sufficient capacity to supply the maximum expected load requirement is not assured. Therefore, the battery must be immediately declared inoperable and the corresponding DC control power source to the 125VDC switchyard distribution system must be declared inoperable.
Additiona!!y, other potentially extreme conditions, such as average electrolyte I temperature of representative cells falling below 60*F or battery terminal voltage below the limit are also cause for immediately declaring the associated DC control power j source to the 125VDC switchyard distribution system inoperable. '
References SAR, Section 8.2.1.3 ANO-1 TRM 3.7-3 Rev.1
s 4.1 AUXILIARY ELECTRICAL SYSTEMS SURVEILLANCE REQUIREMENTS 4.6.1 Switchyard DC Sources and Batteries l
l Applicability Applies to the periodic testing and surveillance requirements of the 125 VDC Switchyard Distribution System to ensure it will respond properly when required.
Requirements 4.6.1.1 Verify battery terminal voltage is 2124.7 V on float charge once each 7 days.
4.6.1.2 Verify battery capacity is adequate to supply, and maintain in operable status, the required emergency loads for the design duty cycle when subjected to either a battery service test or a modified performance discharge test once every 18 months.
4.6.1. 3 Verify battery capacity is 2 80% of the manufacturers rating when subjected to a performance discharge test or a modified performance discharge test once every 60 months, once every 24 months when battery has reached 85%
of the service life with capacity 2100% of the manufacturers rating and showing no degradation, and once every 12 months when battery shows degradation or has reached 85% of the service life and capacity is < 100% of the manufacturer's rating.
4.6.1. 4 Connect and load the battery charger to its 125 VDC distribution system for at least 30 minutes during every quarter.
4.6.1.5 Verify battery pilot cell parameters meet TRM Table 4.6.1-1 Category A limits once per 7 days.
4.6.1.6 Verify average electrolyte temperature of representative cells is 2 60*F once per 92 days.
4.6.1.7 Verify battery cell parameters meet TRM Table 4.6.1-1 Category B limits once per 92 days and once within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a battery discharge to < 110 V and once within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a battery overcharge to > 150 V.
ANO-1 TRM 4.6-1 Rev. O
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TRM Tabla 4.6.1-1 !
Battery Cell Surveillance Requirements i
CATEGORY A: CATEGORY B: CATEGORY C: i LIMITS FOR EACH LIMITS FOR EACH ALLOWABLE LIMITS j DESIGNATED CONNECTED CELL FOR EACH PARAMETER PILOT CELL CONNECTED CELL
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! l l Electrolyte Level > Minimum level > Minimum level Above top of plates, )
indication mark, and indication mark, and and not overflowing !
s 1/4 inch above s 1/4 inch above I maximum level maximum level j indication mark (*) indication mark '
Float Voltage 2 2.13 V 2 2.13 V > 2.07 V Specific Gravity" 2 1.195 2 1.190 Not more than 0.020 .
below average )
AND connected cells A l
Average of all AND !
connected cells i
> 1.195 Average of all connected cells 1 2 1.190 1
(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.
(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.
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ANO-1 TRM 4.6 2 Rev. O
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The TRM 4.6.1.1 verification of battery terminal voltage while on float charge 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 battery charger is supplying the continuous charge required to overcome the internallosses of a battery and maintain the battery in a fully charged state. The voltage requirements are based on the nominal design voltage of the battery (2.15 V per cell average) and are consistent with the battery vendor allowable minimum volts per celllimits. The inability to meet this requirement constitutes an inoperable battery.
The TRM 4.6.1.2 battery service test is a special test of the 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. A performance discharge test or a modified performance discharge test may be performed in lieu of a service test. The inability to meet this requirement constitutes an inoperable battery.
The modified performance discharge test is a simulated duty cycle consisting of just two rates; the one minute rate published for the battery or the largest current load of the duty cycle, followed by the test rate employed for the performance test, both of which envelope the duty cycle of the battery. Since the ampere-hours removed by a rated one minute discharge represents a very small portion of the battery capacity, the test rate can be changed to that for the performance 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 voltage specified in the battery service test for the duration of time equal to that of the service test.
A modified performance discharge test is a test of the battery capacity and its ability to provide a high rate, short duration load (usually the highest rate of the duty cycle). This will often confirm the battery's ability to meet the critical period of the load duty cycle, in addition to determining its percentage of rated capacity. Initial conditions for the modified performance discharge test should be identical to those specified for a service test and the test discharge rate must envelope the duty cycle of the service test if the modified performance discharge test is performed in lieu of a service test.
The TRM 4.6.1.3 battery performance discharge test is a test of constant current capacity of a battery after having been in service, to detect any change in the capacity determined by the acceptance test. The test is intended to determine overall battery degradation due to age and usage. The inability to meet this requirement constitutes an inoperable battery.
Either the battery performance discharge test or the modified performance discharge test, described above, is acceptable for satisfying TRM 4.6.1.3; however, only the modified performance discharge test may be used to satisfy TRM 4.61 ' while satisfying the requirements of TRM 4.6.1.2 at the same time.
The acceptance criteria for this surveillance are consistent with IEEE-450. This reference recommends that the battery be replaced if its capacity is below 80% of the ANO-1 TRM 4.6-3 Rev. O
.j manufacturar's rating. A capacity of 80% shows that the battery rato of dsterioration is increasing, even if there is ample capacity to meet the load requirements.
The frequency for this test is normally 60 months. If the battery shows signs off degradation, or if the battery has reached 85% of its service life and capacity is < 100%
of the manufacturer's rating, the frequency is reduced to 12 months. However, if the battery shows no degradation but has reached 85% of its service life, the frequency is only reduced to 24 months for batteries that retain 2100% of the manufacturer's ratings.
Degradation is indicated, according to IEEE-450, when the battery capacity drops by more than 10% relative to its capacity on the previous performance test or when it is 210% below the manufacturer's rating.
l TRM 4.6.1.4 requires that each required battery charger be capable of supplying the connected loads while maintaining the battery fully charged.
TRM 4.6.1.5 verifies that the TRM Table 4.6.1-1 Category A battery cell parameters are consistent with vendor recommendations and IEEE-450, which recommend regular battery inspections (at least once per month) includi.ig voltage, specific gravity, and !
electrolyte level of pilot cells. I The TRM 4.6.1.6 verification that the average temperature of representative cells is 2 60oF is consistent with a recommendation of IEEE-450, which states that the temperature of electrolytes in representative cells (~10% of all connected cells) should be determined on a quarterly basis. Lower than normal temperatures act to inhibit or reduce battery capacity. This surveillance ensures that the operating temperatures remain within an acceptable operating range. This limit is based on manufacturer recommendations.
TRM 4.6.1.7 verifies that the TRM Table 4.6.1-1 Category B battery cell parameters are l consistent with vendor recommendations and IEEE-450, which recommend regular battery inspections (at least once per quarter) including voltage, specific gravity, and electrolyte level of each connected cell. In addition, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a battery discharge to < 110 V or a battery overcharge to > 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 s 110 V, do not constitute a battery discharge provided battery terminal voltage and float current return to pre-transient values. This inspection is also consistent with IEEE-450, 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.
TRM Table 4.6.1-1 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 cellin 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, with the extra 1/4 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 TRM ANO-1 TRM 4.6-4 Rev. O
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g l Tabla 4.6.1-1 parmits the electrolyte level to be above the specified maximum level during equalizing chargo, 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 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 2 2.13 V per cell. This value is based on the battery vendor allowable minimum cell voltage and on a recommendation of IEEE-450, 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 21.195. This value is characteristic of a charged cell with adequate capacity. According to IEEE-450, the specific gravity readings are based on a temperature of 77'F (25'C).
The specific gravity readings are corrected for actual electrolyte temperature. For each 3*F (1.67'C) above 77'F (25'C),1 point (0.001) is added to the reading; 1 point is subtracted for each 3*F below 77*F. The specific gravity of the electrolyte in a cell increases with a loss of water due to electrolysis or evaporation.
l Category B defines the normal parameter limits for each connected cell. The term
" connected cell" excludes any battery cell that is 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 cellis 21.190 with the average of all connected cells > 1.195. 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 parameteris 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 is based on IEEE-450, 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 limits of average specific gravity 21.190 is based on manufacturer recommendations. 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.
Footnotes (b) and (c) to TRM Table 4.6.1-1 are applicable to Category A, B, and C specific gravity. Footnote (b) to TRM Table 4.6.1-1 requires the above mentioned correction for ANO-1 TRM 4.6-5 Rev. O
elactrolyta tempsraturo. This current provides, in gansral, an indication of overall battery condition. The value of 2 amps used in footnote (c)is the nominal value for float current established by the battery vendor as representing a fully charged battery with an j allowance for overall battery condition.
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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.
Footnote (c) to TRM Table 4.6.1-1 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. j Following a minor battery recharge (such as equalizing charge that does not follow a i deep discharge) specific gravity gradients are not significant, and confirming measurements may be made in less than 7 days.
References None ANO-1 TRM 4.6-6 Rev. O