ML20092J591

Safety Evaluation Supporting Amends 177 & 158 to Licenses DPR-70 & DPR-75,respectively

ML20092J591
Person / Time
Site:	Salem
Issue date:	09/19/1995
From:	NRC (Affiliation Not Assigned)
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NUDOCS 9509220240
Download: ML20092J591 (9)

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• h UNITED STATES E

NUCLEAR REGULATORY COMMISSION 4

5 WASHINGTON, D.C. 20066 4001

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION

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RELATED TO AMENDMENT NOS. 177 AND 158 TO FACILITY OPERATING 1

LICENSE NOS. DPR-70 AND DPR-75 i

3 PUBLIC SERVICE ELECTRIC & GAS COMPANY i

PHILADELPHIA ELECTRIC COMPANY i

i DELMARVA POWER AND LIGHT COMPANY

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ATLANTIC CITY ELECTRIC COMPANY l

j SALEM NUCLEAR GENERATING STATION. UNIT NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311 l

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1.0 INTRODUCTION

i-1 By letter dated January 21, 1994, as supplemented June 28 and, September 13, 1994, and April 4,1995, the Public Service Electric & Gas Company (the l'

licensee) submitted a request for changes to the Salen Nuclear Generating Station, Unit Nos. I and 2, Technical Specifications (TS). The requested t

changes would revise TS 3.8.2.3, "125-Volt D.C. DISTRIBUTION - OPERATING".

l The June 28 and September 13, 1994, and April 4, 1995, letters provided clarifying information that did not change the initial proposed no significant hazards consideration determination, nor go beyond the scope of the Federal Reaister notice.

i The proposed changes include the addition of a table giving the specific battery cell parameters and revision of the limiting condition for operation (LCO) and surveillance requirement (SR) in accordance with the recommendation in NUREG-1431, " Westinghouse Owner's Group Improved Standard Technical i

Specifications" (WOG STS). The licensee also proposes a revision to eliminate the differences between the Salem Unit 1 TS and the Salem Unit 2 TS, thus j

bringing both TS into agreement.

With the use of battery cell parameters as recommended in the WOG STS, the licensee believes that it can establish overall battery acceptability and F

i-provide the flexibility needed to address changes in individual battery cell performance over the battery's life, while ensuring that overall battery

- performance meets or exceeds minimum design requirements.

It also provides

. additional SRs to allow for improved monitoring of battery capabilities and

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1 2.0 EVALUATION I

The staff.has reviewed the proposed changes in TS 3.8.2.3 and the b'attery cell 4

parameter requirements shown in Table 4.8.2.3-1.

The staff's evaluation of i

each proposed.TS amendment for Sales units 1 and 2-is as follows:.

l 2.1 Mod'ification-of LCO 3.8.2.3 for Unit l

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Under current LCO 3.8.2.3 for Unit 1, each of three dc: trains, which consists 2

of 125-V de bus, battery, and at least one full battery capacity charger, must be energized and operable for normal plant operation.

Each dc bus can be powered by two battery chargers:. the primary charger from the 230-V ac vital system within the same train, and the backup charger from a different 230-V ac-

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vital, system train.

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'In proposed LCO 3.8.2.3, specific battery chargers are identified for each p

- train (i.e., lAl for. train IA,181.for train 18, and 101 for train IC) for Unit 1; the licensee believes that this will eliminate the ambiguity in the I

currant LCO phrase "at least one full capacity charger" and also will prevent L

the plant from operating indefinitely with a de bus on the backup battery charger.

'Since the primary battery chargers already have'been identified as 2Al for

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train 2A, 2B1 for train 2B, and 2C1 for train 2C in a similar LCO for Unit 2,

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the staff concurs with the licensee's rationale that proposed LCO 3.8.2.3 for Unit I will automatically limit plant operation with the backup battery l_.

. charger and finds it to be more restrictive. This change brings both units' LCO into agreement. On this basis, the staff concludes the licensee's

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proposed LCO 3.8.2.3 for Unit 1 is acceptable.

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. 2.2 Modification of Action Statement (AS) 3.8.2.3.a for Unit 2 Current AS.3.8.2.3.a for Unit 2 reads "With one 125-volt D.C. bus inoperable or not eneraized, restore the inoperable bus to OPERABLE and eneraized status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or..."

To make the AS consistent with that for Unit 1, the i

licensee proposes to delete the above underlined wording from AS 3.8.2.3.a for i

i Unit 2.

Since a similar AS (i.e., AS 3.8.4.A) in the UOG STS does not contain the above wording and the deletion brings the ass for'both units'into agreement, the proposed change to AS 3.8.2.3.a for Unit 2 is acceptable.

I 2.3 Modification of AS 3.8.2.3.b for Units 1 and 2 l,

h The licensee proposes to modify AS 3.8.2.3.b as follows: (1) for Unit 1, by changing " battery and/or charger" to " battery charger" and limiting the use of-l the backup battery charger to 7 days by adding an appropriate j

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I' clause "0R connect the backup charger for no more than 7 days OR...," and (2) for Unit 2, by changing AS 3.8.2.3.c to AS 3.8.2.3.b by removing current AS l

3.8.2.3.b.

The'125-V de power system provides motive and control power to valves,

. instrumentation, emergency diesel. generators, and many other components and systems during all phases of plant operation. At Sales, any de component 1-(e.g., de bus, battery, and battery charger) is vulnerable to a single failure i

l when a dc bus is on the backup charger that could prevent the de system from i

i performing its intended safety function. The staff was concerned about this 3

single failure vulnerability during the Unit 2 licensing stage and raised many 3-questions about the independence and redundancy of the backup battery charger.

j In Supplement 4 of the Salem Unit 2 safety evaluation report (NUREG-0517), the staff agreed to allow the use of the backup battery charger for 7 days per AS 3.8.2.3.c of the TS.

In the current amendment request, the licensee asks that l

l the same provision be extended for Unit 1 because the de and ac power l

" distribution systems at Salem Units 1 and 2 are identical.

In addition, the j

licensee asks that the battery inoperability provision for Units 1 and 2 in AS 3.8.2.3.b be addressed separately in other parts of the TS.

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The staff concurs with the licensee that the proposed changes bring the TS for both units into agreement, that is (1) for Unit 1, limiting the use of the backup battery charger to 7 days in AS 3.8.2.3.b, and changing the wording in AS 3.8.2.3.b; and (2) for Unit 2, changing AS 3.8.2.3.c to AS 3.8.2.3.b by i

removing the current AS 3.8.2.3.b.

The staff concludes that the proposed changes are acceptable.

2.4 Addition of Table 4.8.2.3-1. " Battery Cell Parameter Reauirements." for i-Units I and 2 i

Since battery cell parameters must be within acceptable limits to ensure that i

i the required de power is available to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence or a postulated design basis accident, the licensee proposes to add Table 4.8.2.3-1, " Battery Cell Parameters Requirements," for both units. The table gives the limits for electrolyte level, float voltage, and specific gravity for three different categories: Category A which defines the normal parameter limits for each designated pilot cell in each battery; Category B, which defines the normal parameter limits for each connected cell; and Category C, which defines the l

allowable limits for each connected cell.

The staff has reviewed each parameter value proposed for electrolyte level, i

floating voltage, and specific gravity for all three categories and the i

associated footnotes in Table 4.8.2.3-1 and compared them with those of Table

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3.8.6-1 in the WOG STS and finds them to be identical except for the following:

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The floating voltage in Category C is greater than or equal to 2,07 V rather than greater than 2.07 V.

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The specific gravity values for all three categories are lower by five points (0.005).

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The battery charging current when on float charge shown in footnotes b and c is 3 amps rather than 2 amps.

Although cell voltage is not by itself an indication of the state of charge of 1

i the battery, Appendix C (Section C1. Low-Voltage Cells) of IEEE Std 450-1993, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," states that prolonged i

i operation of cells below 2.13 V can reduce the life expectancy of cells and a j-cell voltage of 2.07 Y or below under float conditions will indicate internal cell problems and may require cell replacement. Thus, the float voltage level should be greater than 2.07 V.

By letter dated June 28, 1994, the licensee agreed to revise the float voltage level to greater than 2.07 V.

During a teleconference on May 11, 1994, the staff expressed concern about the i

low specific gravity values for each category and the high battery charging i

current. The licensee contends that the values in Table 3.8.6-1 of the WOG STS for specific gravity and for floating charge current are bracketed values i

that require plant specific information and that they were furnished by the battery manufacturer (C&D) as typical' values for the batteries installed at i

Salem (LC/LCR-33 with 1.215 specific gravity cells).

l By letter dated September 13, 1994, the licensee submitted its supporting i

document for the above parameters obtained from the battery manufacturer, in i

i which it stated that the reduced specific gravity values by five points in

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each category would not affect operability unless the battery design and aging 1

margins were compromised. The basis for the licensee's recommendation is that i

a fully charged battery with all cells having a measured specific gravity of i

1.190 (licensee's proposed value) will have approximately 93 percent of the

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performance capability, while the same battery with 1.195 (WOG STS value) specific gravity will have approximately 94 percent. The manufacturer also stated that 1.190 specific gravity in all cells, nominal floating voltages, 4

and a charging current less than 3 amps would indicate that the battery has sufficient capacity to meet its design loads.

Regarding the staff's concern i

whether the batteries at Salem have enough design and aging margins, the licensee confirmed that its batteries are sized based on the basis of IEEE Std j

485-1983 with appropriate margins (i.e., 145 percent battery capacity) to meet their required duty cycles.

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Considering the. licensee's confirmation of its battery margins and.

supplemental information provided by the battery manufacturer, the staff finds L

that the battery cell parameters proposed by the licensee are comparable with i

the parameters shown in Table-3 8.6-1 of the WOG STS. Therefore, addition of j

-Table 4.8.2.3-ILin the TS for Units 1 and 2 is acceptable.

2.5 Addition of ass 3.8.2.3.c. d. e. and f for Units 1 and 2 l

With the addition of Table *4.8.2.3-1, which gives battery cell parameter i

requirements, the licensee proposes to address battery inoperability for both j

units.in ass 3.8.2.3c, d, e, and f as follows:

2.5.1 AS 3.8.2.3.c With one or more 125-volt D.C. batteries with one or more battery cell j

parameters not within the Category A or B limits of Table 4.8.2.3-1:

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Verify within I hour, that the electrolyte level and float voltage for the' pilot cell meets Table 4.8.2.3-1 Category C limits; I

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Verify within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, that battery cell parameters of all connected cells meet Table 4.8.2.3-1 Category C limits; 3.

Restore battery cell parameters to Category A and B limits of Table 4.8.2.3-1 within 31 days; and 9

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If any of the above listed requirements cannot be met, comply with l

' the requirements of AS 3.8.2.3.f.

2.5.2 AS 3.8.2.3.d With one or more 125-volt D.C. batteries with one or more battery cell parameters not within Table 4.8.2.3-1 Category C values, comply with the requirements of AS 3.8.2.3.f.

2.5.3 AS 3.8.2.3.e With average electrolyte temperature of representative cells less than 65 'F, comply with the requirements of AS 3.8.2.3.f.

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2.5.4 AS 3.8.2.3.f

. Restore the battery to OPERABLE status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> OR be in at least HOT

. STANDBY.within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> AND COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

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The staff has reviewed ass (i.e.,3.8.6.A and B) in the battery cell parameter

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' section of the WOG STS that are similar to the ass proposed by the licensee.

.The staff finds that proposed ass 3.8.2.3.c, d, e, and f are consistent with i

ass 3.8.6.A and B of the WOG STS in determining the operability of the battery I

except for the difference in temperature in AS 3.8.2.3.e.

Proposed AS j

3.8.2.3.e requires the average temperature of representative cells to be less than 65 *F; the similar AS (i.e., 3.8.6.B) in the WOG STS requires a temperature of less than 60 *F.

With battery temperature below 65 *F, the j

licensee contends that the capacity to supply the maximum expected load requirement is not ensured, thus making the corresponding de electrical power j

subsystem inoperable. Since 65 *F is more limiting and restrictive than 60 j

• F, the staff finds 65 'F to be acceptable. The staff concludes that proposed j

ass 3.8.2.3.c, d, e, and f are acceptable.

i 2.6 Modification of Surveillance Reouirement (SR) 4.8.2.3.2.a for Units 1 and 2.

j As'a part of weekly (i.e., 7 day) battery surveillance, there are four SR provisions (i.e., SR 4.8.2.3.2.a.1-4).

The licensee proposes to delete the i

first three of the four existing SR provisions (i.e., SR 4.8.2.3.2.a.1-3) and i

to replace them with SR 4.8.2.3.2.a.1 and to change SR 4.8.2.3.2.a.4 to SR 4.8.2.3.2.a.2.

With the addition of the new battery cell parameter requirements table, proposed SR 4.8.2.3.2.a.1 states that "The parameters in i

the Table 4.8.2.3-1 meet Category A limits." while SR 4.8.2.3.2.a.2 remains the same.

1 The staff has compared the proposed SR provisions with similar provisions in the WOG STS and finds that proposed SRs 4.8.2.3.2.a.1 and 4.8.2.3.2.a.2 are i

identical to SRs of the WOG STS, respectively. Therefore, proposed SRs 4.8.2.3.2.a.1 and 4.8.2.3.2.a.2 are acceptable.

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l 2.7 Modification of SR 4.8.2.3.2.b for Units 1 and 2 i

i The licensee proposes to replace SR 4.8.2.3.2.b.1-3 with SR 4.8.2.3.2.b, which l

states, "At least 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 i

discharge < 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 > 150 V t

by verifying that the parameters in Table 4.8.2.3-1 meet the Category B l

limits." The staff has compared proposed SR 4.8.2.3.2.b with SR 3.8.6.2 in the WOG STS and finds it to be identical. The staff concludes that the modification of SR 4.8.2.3.2.b for Units 1 and 2 is acceptable.

4 2.8 Addition of SRs 4.8.2.3.2.c.1 and 2 for Units 1 and 2

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The licensee proposes to add two more battery SRs, 4.8.2.3.2.c.1 and 2:

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SR 4.8.2.3.2.c.1

.SR 4.8.2.3.2.c.1 is being added to verify that-there-is no visible corros%n L

at battery terminals and connectors.or to verify connection resistance v!. lues i

for inter-cell, inter-rack, inter-tier, terminal, and total battery connections. This SR can indicate physical damage or abnormal deterir4ation i

that could potentially degrade battery performance. The licensee st Ges that

.the specific resistance value limits in the SR are based on not ercueding the ceiling values established by the manufacturer.

Because proposed SR 4.8.2.3.2.c.1 format agrees with SR 3.8.4.2 in the WOG STS j"

and this surveillance can detect conditions that can cause power losses due to 1

resistive heating, the staff finds that the proposed SR 4.8.2.3.2.c.1 is i

. acceptable.

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l2.8.2 SR 4.8.2.3.2.c.2 f

. SR 4.8.2.3.2.c.2 is being added to verify that the average electrolyte l

ll' temperature of representative cells'is above 65 'F, instead of 60 'F as r

prescribed in SR 3.8.6.3 of the WOG STS. The licensee states that the 65 'F limit is based on the minimum temperature to ensure that the required loads will have adequate terminal voltage under the station blackout (580) coping time calculations. Since lower than' normal temperature inhibits or reduces j

battery capacity, the licensee believes that the higher temperature proposed i

in the SR will ensure that the operating temperature remains within an i'

acceptable operating range.

1 she staff finds that the licensee's proposed change (i.e., 65 "F) is more 4

restrictive than the manufacturer's recommended temperature of 60 'F.

j Proposed SR 4.8.2.3.2.c.2 is, therefore, acceptable.

2.9 Modification of SRs 4.8.2.3.2.d.l. 2. 3.and 4 for Units 1 and 2

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With the addition of SRs 4.8.2.3.2.c.1 and 2, the licensee finds it necessary to change three SRs 4.8.2.3.2.c.1, 2, and 3 to SRs 4.8.2.3.2.d.1, 2, and 3, and to change SR 4.8.2.3.2.c.4 to SR 4.8.2.3.2.e.

In addition, it proposes to reduce the surveillance frequency from 18 months to 12 months.

The licensee r

contends that the proposed 12 month testing frequency is consistent with the guidance of IEEE Std 450-1987. Specific SR changes requested are as follows:

1.

The current SR 4.8.2.3.2.c.) should be changed to SR 4.8.2.3.2.d.l.

2.

The current SR 4.8.2.3.2.c.2, which states, "The cell-to-cell and terniinal connections are clean, tight, and coated with anti-corrosion i

material'." should be modified to state " Remove visible terminal i

corrosion and verify cell-to-cell and terminal connections are coated with anti-corrosion. material." The change is the removal of the words

" clean and tight". SR 4.8.2.3.2.c.2 should be changed to SR

'4'.8.2.3.2.d.2.

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The current SR 4.8.2.3.2.c.3, which requires that only the resistance of each cell-to-cell and terminal connection be measured, should be expanded to include resistances for inter-cell, inter-rack, inter-e tier, field cable, and total battery connections.

SR 4.8.2.3.2.c.3 should be changed to SR 4.8.2.3.2.d.3.

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The currer' SR 4.8.2.3.2.c.4 should be changed to SR 4.8.2.3.2.e.

The staff has reviewed the following proposed changes: (1) changing i

the surveillance frequency from 18 months to 12 months, (2) removing the words " clean and tight," and (3) expanding resistance measurements of various additional connections and components.

In addition, the staff compared the proposed SR provisions with the guidance given in IEEE standards on batteries and manufacturer's recommendations, and finds the following:

1.

IEEE Std 450-1987 recommends that these inspections be performed on a 1

yearly basis instead of every 18 months. The proposed (12 month) testing frequency is consistent with this guidance.

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The reason for the removal of the requirement to verify that the terminal connections are clean and tight from SR 4.8.2.3.2.c.3 is to i

prevent overtightening of battery connections and removing the a

i requirement is recommended by IEEE Std P1106, "IEEE Recommended Practice for Installation, Maintenance, Testing, and Replacement of Vented Nickel-Cadmium Batteries for Stationary Applications."

In addition, the licensee believes that cleanness and tightness can be i

verified by measuring the resistance connections. The words j

" cleanness and tightness," therefore, are not necessary.

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The resistance limits shown in SR 4.8.2.3.2.c.3 are based on the ceiling values provided by the battery manufacturer to ensure that the battery connection resistance does not exceed an established maximum value.

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On the basis of the above findings, the staff concludes that the licensee's proposed changes are consistent with the SR provisions recommended in the WOG i

STS, the IEEE standards and manufacturer's recommendations, and are, therefore, acceptable.

2.10 Chanae SR 4.8.2.3.2.d to SR 4.8.2.3.2.f and SR 4.8.2.3.2.e to SR 4.8.2.3.2.a for Units 1 and 2 i

As a result of the renumbering of SRs in various sections of the TS, the licensee finds it necessary to change SRs 4.8.2.3.2.d and 4.8.2.3.2.e to SRs 4.8.2.3.2.f and 4.8.2.3.2.g.

Since this change does not involve any changes l

in content, the staff finds it to be acceptable.

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2.11 edditions of SRs 4.8.2.3.2.h and 4.8.2.3.2.1 for Units 1 and 2 2.11.1 SR 4.8.2.3.2.h The licensee proposes to add SR 4.8.2.3.2.h, which states, "At least once per 12 months, during shutdown; if the battery shows signs of degra'dation OR has reached 85% of the service life with a capacity less than 100% of manufacturers rating, by verifying that the battery is at least 80% of the manufacturer's rating when subjected to a performance discharge test.

Degradation is indicated when the battery capacity drops more than 10% of the rated capacity from its capacity on the previous performance test, or is below 90% of the manufacturer's rating."

i The staff has reviewed a similar provision (i.e., SR 3.8.4.8) in the WOG STS, which requires that the performance discharge test be conducted every 12 months if the battery shows degradation or has reached 85 percent of its expected life. According to IEEE Std-450, the battery has degraded if its capacity has dropped more that 10 percent relative to its capacity on the previous performance test or when it is below the manufacturer's rating. On this basis, the staff finds that proposed SR 4.8.2.3.2.h is consistent with the recommendations of the WOG STS and IEEE Std-450 and, therefore, its addition is acceptable.

2.11.2 SR 4.8.2.3.2.1 The licensee also proposes to add SR 4.8.2.3.2.1, which states, "At least once per 24 months, during shutdown, if the battery has reached 85% of the service life with capacity greater than or equal to 100% of manufacturers rating, by verifying that the battery capacity is at least 80% of the manufacturer's rating when subjected to a performance discharge test."

Although this provision is not yet in the WOG STS, it is in accordance with the latest (1993) version of IEEE Std-450 recommendation. Also, in the EELB's memorandum dated June 16, 1993, from C. H. Berlinger to C. I. Grimes, EELB concurred with the Technical Specification Branch on the addition of the above TS provision in the future WOG STS as it may help to lengthen the life of batteries while still providing a timely warning of approaching end of battery life. Therefore, the staff concludes that the addition of SR 4.8.2.3.2.1 is acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the New Jersey State official was notified of the proposed issuance of the amendments.

The State official had no comments.

- 4. 0. ENYlRQltElilALCQlLilDEBaIl0E

- The amendments change a requirement with respect to installation or use of a

- facility component-located within the restricted area as defined in 10 CFR Part-20 and change the Surveillance Requirements. The NRC staff has determined that.the amendments-involve no significant increase in the amounts,

- and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational-radiation-expo'sure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and.there has-been no public comment on such finding (59FR22012). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be x

prepared in connection with the issuance of the amendments.

' 5~.0 CONCLUSION The Commission has concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted-in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common 4

defense and security or to the health and safety of the public-.

j Principal Contributor:

P. Kang Date: September 19,.1995 i

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