Text

Revs Made to BSEP TS Bases Between 980605 & 990507,IAW TS 5.5.10.d
	ML20206R793
Person / Time
Site:	Brunswick
Issue date:	05/17/1999
From:	; CAROLINA POWER & LIGHT CO.
To:	;
Shared Package
ML20206R791	List: BSEP-99-0080, Forwards Revs Made to TS Bases Between 980605 & 990507 Without Prior NRC Approval; ML20206R793;
References
	NUDOCS 9905200201
	Download: ML20206R793 (200)
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l ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 AND 50-324 LICENSE NOS. DPR-71 AND DPR-62 SUBMITTAL OF TECHNICAL SPECIFICATION BASES CHANGES l

Summary List of Revisions l l

Technical Specification 5.5.10. " Technical Specifications (TS) Bases Control Program," Item d I requires changes made to the Bases, implemented without prior NRC approval, to be provided to j the NRC on a frequency consistent with 10 CFR 50.71(e). The following table summarizes the changes made to the TS Bases for the Brunswick Steam Electric Plant (BSEP), Unit Nos. I and 2 between June 5,1998, and May 7,1999.

BSEP TS Bases Revisions !

June 5,1998, to May 7,1999

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Unit 1 - Rev. I 7/21/98 Single Loop Operation Multiplier Restriction Unit 2 - Rev.1 Revision i for Units I and 2 modified B 3.4.1 to describe single loop operation multiplier restrictions imposed in the Core Operating Limits Report to maintain the loss-of-coolant accident peak clad temperature limit below the two loop operation limit.

Unit 1 - Rev. 2 7/23/98 SRM/IRM Overlap Methodology Unit 2 - Rev. 2 i Revision 2 for Units I and 2 modified B3.3.1.1 to change the acceptance i criteria associated with the Source Range Monitor (SRM)/ Intermediate Range Monitor (IRM) overlap surveillance (SR 3.3.1.1.6) to be more consistent with IRM instrumentation design.

Unit 1 - Rev. 3 9/14/98 Description of Suppression Chamber Water Unit 2 - Rev. 3 Temperature /Drywell Temperature Instrumentation Revision 3 for Units 1 and 2 modified B 3.3.3.1 to clarify the number of temperature sensors and system design associated with Functions 4 (i.e.,

Suppression Chamber Water Temperature) and 7 (i.e., Drywell Temperature) of ITS Table 3.3.3.1-1, " Post Accident Monitoring Instrumentation."

9905200201 990517 PDR ADOCK 05000324 P PDR El-1

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BSEP TS Bases Revisions June 5,1998, to May 7,1999 s .w ,-m .

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Unit 1 - Rev. 4 2/10/99 HPC1/RCIC Steam Line low Pressure Unit 2 - Rev. 4 Revision 4 for Units I and 2 modified the bases for Functions 3.c,4.c (i.e.,

HPCI and RCIC Steam Supply Line Pressure - Low) of TS Table 3.3.6.1-1 to accurately reflect the basis for these functions.

Unit 1 - Rev. 5 4/22/99 Group 8 Isolation On Reactor Water Level - Low Level 1 Unit 2 - Rev. 5 Revision 5 for Units 1 and 2 modified the B 3.3.6.1.2.a. to include Group 8 in list of primary containment isolation valves isolated by Reactor Vessel Water Level - Low Level 1.

Unit 1 - Rev. 6 4/27/99 Bases Change For Amendments 205 and 235 Unit 2 - Rev. 6 Revision 6 for Units I and 2 modified B 3.8.1 and B 3.8.7 to reflect changes made by Amendments 205 and 235, " Extension Of Allowed Outage Time For Balance Of Plant And Emergency Electrical Buses,"

dated 4/15/99. The entire B 3.8 section was re-paginated as a result.

Unit 1 - Rev. 7 5/6/99 TS 3.8.7, Condition C Entry Condition Unit 2 - Rev. 7 Revision 7 for Units I and 2 modified B 3.8.7 to provide clarification of the applicability of entry into TS 3.8.7, Condition C.

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F ENCLOSURE 2 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 AND 50-324 LICENSE NOS. DPR-71 AND DPR-62 SUBMFITAL OF TECHNICAL SPECIFICATION B ASES CHANGES l

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Bases Page Replacement Instructions i

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N/A Title Page - Revision 7 N/A LOEP 1, Revision 7 N/A LOEP 2, Revision 3 N/A LOEP 3, Revision 5 N/A LOEP 4 Revision 3 B 3.3-30, Revision 0 B 3.3-30, Revision 2 l

B 3.3-77 through B.3.3-85, Revision 0 B 3.3-77 through B.3.3-85 Revision 3 B 3.3-153, Revision 0 B 3.3-153 Revision 5 B 3.3-156, Revision 0 B 3.3-156 Revision 4 Bases Unit 1 - B 3.4 - B 3.10 -

Remove Insert N/A LOEP 1 Revision 7 1

N/A LOEP 2, Revision 3 N/A LOEP 3, Revision 6 N/A LOEP 4, Revision 7 l

N/A LOEP 5, Revision 6 Table of Contents, Page ii, Revision o Table of Contents, Page ii, Revision 7 B 3.4-3 through B 3.4-6, Revision 0 B 3.4-3 through B 3.4-6, Revision 1 B 3.8-6 through B 3.8-84, Revision 0 B 3.8-6 through B 3.8-78, Revision 6 N/A B 3.8-79 through B 3.8-91, Revision 7 E2-1

I Bases Unit 2 - B 2.0 '- B 3.3 Remove Insert N/A Title Page - Revision 7 N/A LOEP 1, Revision 7 N/A LOEP 2, Revision 3 I N/A LOEP 3, Revision 5 N/A LOEP 4, Revision 4 i B 3.3-30, Revision 0 B 3.3-30, Revision 2 l

B 3.3-77 through B.3.3-85, Revision 0 B 3.3-77 through B.3.3-85 Revision 3 j B 3.3-154, Revision 0 B 3.3-154 Revision 5 B 3.3-157, Revision 0 B 3.3-157 Revision 4 Bases Unit 2 - B 3.4 - B 3.10 Remove Insert N/A LOEP 1, Revision 7 N/A LOEP 2, Revision 3 N/A LOEP 3 Revision 6 N/A LOEP 4, Revision 7 N/A LOEP 5, Revision 6 Table of Contents, Page ii, Revision 0 Table of Contents, Page ii, Revision 7 B 3.4-3 through B 3.4-6, Revision 0 B 3.4-3 through B 3.4-6, Revision 1 B 3.8-6 through B 3.8-84, Revision 0 B 3.8-6 through B 3.8-78, Revision 6 N/A B 3.8-79 through B 3.8-91, Revision 7 l

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ENCLOSURE 3 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 AND 50-324 LICENSE NOS. DPR-71 AND DPR-62 SUBMITTAL OF TECHNICAL SPECIFICATION BASES CHANGES Unit 1 and Unit 2 Replacement Bases Pages I

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Bases Unit 1 - B 2.0 - B 3.3 Replacement Pages l

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BASES TO THE FACILITY OPERATING LICENSE DPR-71 TECHNICAL SPECIFICATIONS FOR BRUNSWICK STEAM ELECTRIC PLANT UNIT 1 CAROLINA POWER & LIGHT COMPANY i REVISION 7 5

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Title Page 7 8 3.1-7 0 l B 3.1-8 0 List of Effective Pages - Book i B 3.1-9 0 B 3.1-10 0 L0EP-1 7 8 3.1-11 0 i L0EP-2 3 8 3.1-12 0 LOEP-3 5 B 3.1-13 0 L0EP-4 3 8 3.1-14 0 B 3.1-15 0 i 0 B 3.1-16 0 ii 0 B 3.1-17 0 ,

B 3.1-18 0 l B 2.0-1 0 8 3.1-19 0 l B 2.0-2 0 0 3.1-20 0 B 2.0-3 0 B 3.1-21 0 B 2.0 4 0 0 3.1-22 0 l B 2.0-5 0 0 3.1-23 0 B 2.0-6 0 8 3.1-24 0 8 2.0-7 0 8 3.1-25 0 B 2.0-8 0 0 3.1-26 0

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B 3.0-2 0 B 3.1-29 0 i B 3.0-3 0 0 3.1-30 0 B 3.0-4 0 B 3.1-31 0 l B 3.0-5 0 6 2.1-32 0 B 3.0-6 0 8 3.1-33 0 B 3.0-7 0 B 3.1-34 0 B 3.0-8 0 8 3.1-35 0 B 3.0-9 0 B 3.1-36 0 B 3.0-10 0 B 3.1-37 0 B 3.0-11 0 B 3.1-38 0 B 3.0-12 0 B 3.1-39 0 8 3.0-13 0 8 3.1-40 0 8 3.0 14 0 B 3.1-41 0 8 3.0-15 0 B 3.1-42 0 B 3.1-43 0 B 3.1-1 0 B 3.1-44 0 8 3.1-2 0 B 3.1-45 0 0 3.1-3 0 B 3.1-46 0 8 3.1-4 0 B 3.1-47 0 l B 3.1-5 0 B 3.1-48 0 l B 3.1 0 1^

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LIST OF. EFFECTIVE-PAGES - BASES (continued)

Paae No. Revision No. Pace No. Revision No.

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0 B 3.3-32 0 8 3.2-5 0 B 3.3-33 0 B 3.2-6 0 B 3.3-34 0 B 3.2-7 0 8 3.3-35 0 B 3.2-8 0 B 3.3-36 0 ,

B 3.2-9 0 B 3.3-37 0 B 3.2-10 0 B 3.3-38 0 B 3.2-11 0 B 3.3-39 0 B 3.2-12 0 B 3.3-40 0 B 3.2-13 0 8 3.3-41 0 B 3.2-14 0 B 3.3-42 0 i B 3.2-15 0 B 3.3-43 0 l B 3.2-16 0 B 3.3-44 0 B 3.3-45 0 B 3.3-1 0 B 3.3-46 0 B 3.3-2 0 B 3.3-47 0 B 3.3-3 0 B 3.3-48 0 B 3.3-4 0 B 3.3-49 0 8 3.3-5 0 B 3.3-50 0 B 3.3-6 0' B 3.3-51 0 B 3.3-7 0 B 3.3-52 0 B 3.3-8 0 B 3.3-53 0 B 3.3-9 0 B 3.3-54 0 8 3.3-10 0 B 3.3-55 0 B 3.3-11 0 8 3.3-56 0 B 3.3-12 0 B 3.3-57 0 l

8 3.3-13 0 8 3.3-58 0 B 3.3-14 0 B 3.3-59 0 B 3.3-15 0 8 3.3-60 0 B 3.3-16 0 B 3.3-61 0 B 3.3-17 O B 3.3-62 0 B 3.3-18 0 8 3.3-63 0 B 3.3-19 0 B 3.3-64 0 B 3.3-20 0 B 3.3-65 0 B 3.3-21 0 B 3.3-66 0 B 3.3-22 0 B 3.3-67 0 B 3.3-23 0 B 3.3-68 0 B 3.3-24 0 B 3.3-69 0 B 3.3 0 B 3.3-70 0 B 3.3-26 0 8 3.3-71 ,

O B 3.3-27 0 B 3.3-72 0 B 3.3-28 0 (continued)

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LIST OF EFFECTIVE PAGES - BASES (continued)

Pace No. Revision No. Pace No. Revision No.

B 3.3-73 0 B 3.3-115 0 8 3.3-74 0 B 3.3-116 0 B 3.3-75 0 B 3.3-117 0 B 3.3-76 0 8 3.3-118 0 B 3.3-77 3 8 3.3-119 0 B 3.3-78 3 8 3.3-120 0 8 3.3-79 3 B 3.3-121 0 B 3.3-80 3 8 3.3-122 0 B 3.3-81 3 B 3.3-123 0 B 3.3-82 3 8 3.3-124 0 B 3.3-83 3 8 3.3-125 0 B 3.3-84 3 B 3.3-126 0 B 3.3-85 3 8 3.3-127 0 0 3.3-86 0 B 3.3-128 0 8 3.3-B7 0 B 3.3-129 0 B 3.3-88 0 B 3.3-130 0 B 3.3-89 0 B 3.3-131 0 B 3.3-90 0 B 3.3-132 0 8 3.3-91 0 8 3.3-133 0 B 3.3-92 0 B 3.3-134 0 B 3.3-93 0 B 3.3-135 0 B 3.3-94 0 B 3.3-136 0 B 3.3-95 0 B 3.3-137 0 B 3.3-96 0 B 3.3-138 0 B 3.3-97 0 B 3.3-139 0 l

B 3.3-98 0 B 3.3-140 0 B 3.3-99 0 8 3.3-141 0 B 3.3-100 0 B 3.3-142 0 B 3.3-101 0 B 3.3-143 0 B 3.3-102 0 8 3.3-144 0 8 3.3-103 0 B 3.3-145 0 8 3.3-104 0 8 3.3-146 0 B 3.3-105 0 B 3.3-147 0 B 3.3-106 0 B 3.3-148 0 B 3.3-107 0 B 3.3-149 0 B 3.3-108 0 B 3.3-150 0 B 3.3-109 0 8 3.3-151 0 B 3.3-110 0 B 3.3-152 0 B 3.3-111 0 8 3.3-153 5 l B 3.3-112 0 B 3.3-154 0 B 3.3-113 0 B 3.3-155 0 B 3.3-114 0 8 3.3-156 4 (continued)

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l LIST OF EFFECTIVE PAGES - BASES (continued)

Paae No. Revision No. Paae No. Revision No.

B 3.3-157 0 8 3.3-199 0-B 3.3-158 0 B 3.3-200 0 B 3.3-159 0 B 3.3-201 0 B 3.3-160 - 0 B 3.3-202 0 B 3.3-161 0 B 3.3-203 0 B 3.3-162 0 8 3.3-204 0 B 3.3-163 0 B 3.3-205 0 8 3.3-164 0 B 3.3-206 0 B 3.3-165 0 B 3.3-207 0 8 3.3-166 0 B 3.3-208 0 B 3.3-167' 0 8 3.3-209 0 B 3.3-168 0 B 3.3-210 0 B 3.3-169 0 B 3.3-211 0 ;

B 3.3-170 0 B 3.3-212 0 i B 3.3-171 0 1 8 3.3-172 0 B 3.3-173 0 B 3.3-174 0 B 3.3-175 0 B 3.3-176 0 B 3.3-177 0 B 3.3-178 0 B 3.3-179 0 B 3.3-180 0 l' B 3.3-181 0 B 3.3-182 0 B 3.3-183' 0 B 3.3-184 0 i

B 3.3-185 0 B 3.3-186' 0 B 3.3-187 0 l B 3.3-188 0 B 3.3-189 0 B 3.3-190 0

B 3.3-191. O B 3.3-192 0 B 3.3-193 0 B 3.3-194 0 B 3.3-195 0 B 3.3-196 0 B 3.3-19'i 0 B 3.3-198 0 Brunswick Unit 1 L0EP-4 Revision 3 l i 3 , i

RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.6 and SR 3.3.1.1.7 REQUIREMENTS (continued) These Surveillances are established to ensure that no gaps in neutron flux indication exist from subcritical to power operation for monitoring core reactivity status. 1 The overlap between SRMs and IRMs is required to be demonstrated to ensure that reactor power will not be increased into a neutron flux region without adequate '

indication. This is required prior to withdrawing SRMs from the fully insarted position since indication is being transitioned from the SRMs to the IRMs.

The overlap between IRMs and APRMs is of concern when reducing power into the IRM range. On power increases, the system design will prevent further increases (by initiating a rod block) if adequate overlap is not maintained. Overlap between IRMs and APRMs exists.when sufficient IRMs and APRMs concurrently have onscale readings such that the transition between MODE I and MODE 2 can be made without either APRM downscale rod block, or IRM upscale rod block. Overlap between SRMs and IRMs similarly exists when, prior to withdrawing the SRMs from the fully inserted position, IRM i readings have doubled before the SRMs have reached the !

high-high upscale trip.

As noted, SR 3.3.1.1.7 is only required to be met during entry into MODE 2 from MODE 1. That is, after the overlap requirement has been met and indication has transitioned to the IRMs, maintaining overlap is not required (APRMs may be reading downscale once in MODE 2).

If overlap for a group of channels is not demonstrated 1 (e.g., IRM/APRM overlap), the reason for the failure of the i Surveillance should be determined and the appropriate channel (s) declared inoperable. Only those appropriate channels that are required in the current MODE or condition should be declared inoperable.

A Frequency of 7 days is reasonable based on engineering judgment and the reliability of the IRMs and APRMs. !

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Brunswick Unit 1 B 3.3-30 Revision No. 2 l l

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. PAM Instrumentation B 3.3.3.1 BASES LC0 3. Suppression Chamber Water level (continued) of the ECCS suction lines to 5 feet above the normal pool water level. Two wide range suppression pool water level signals are transmitted from separate differential _ pressure transmitters for each channel. The out)ut of one of these channels is recorded on a recorder in tie control room. The 1 output of the other channel is read on an indicator in the I control room. These instruments are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals specifically with this portion of the instrument channel.

4. SuDDression Chamber Water Temperature Suppression chamber water temperature is a Type A and Category I variable provided to detect a condition that could potentially lead to containment breach and to verify the effectiveness of ECCS actions taken to prevent ,

containment breach. The suppression chamber water temperature instrumentation, which measures from 40*F to ;

240*F, allows operators to detect trends in suppression pool water temperature in sufficient time to take action to prevent steam quenching vibrations in the suppression pool.

Suppression pool temperature is monitored by 24 (12 per division) temperature sensors spaced around the suppression pool. A pair of sensors (one per division) is located near I each of the quenchers , the discharge lines of the 11 safety / relief valves. Each pair of sensors is located so as to sense the representative temperature of that sector of the suppression pool even with the associated safety / relief valve open. The outputs for the sensors are indicated on two microprocessors in the control rc:a. The signals from the sensors are conditioned by the two microprocessors to provide an average water temperature. A minimum of 11 out of 12 sensors are required to provide this average per division. Average water temperature is recorded on two independent recorders in the control room. These recorders are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals i specifically with this portion of the instrument channels.

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Brunswick Unit 1 8 3.3-77 Revision No. 3 l

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PAM Instrumentation B 3.3.3.1 l BASES l

LCO 5. Suporession Chamber Pressure I (continued)

Suppression chamber pressure is a Type A and Category I variable provided to detect a condition that could potentially lead to containment breach and to verify the

, effectiveness of ECCS actions taken to prevent containment l breach. Suppression chamber pressure is indicated in the control room from two separate pressure transmitters. The range of indication is O psig to 75 psig. These instruments are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals l specifically with this portion of the instrument channel.

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6. Drywell Pressure Drywell pressure is a Type A and Category I variable provided to detect breach of the RCPB and to verify ECCS functions that operate to maintain RCS integrity. Two wide range drywell pressure signals are transmitted from separate pressure transmitters for each channel. The output of one of these channels is recorded on a recorder in a control room. The output of the other channel is read on an indicator in the control room. The pressure channels measure from -5 psig to 245 psig. These instruments are the primary indication used by the operator during an accident.

Therefore, the PAM Specification deals specifically with this portion of the instrument channel.

1 l 7. Drywell Temperature Drywell temperature is a Type A and Category I variable provided to detect a breach of the RCPB and to verify the effectiveness of ECCS functions that operate to maintain RCS l integrity. Twenty (20) temperature sensors (10 per division) are located in the drywell and suppression pool atmosphere. In order to provide adequate monitoring of the entire air space, a minimum of I sensor per monitoring location, 5 per division are required (Ref. B 3.6.1.4, SR 3.6.1.4.1 for monitoring locations). The sensors are

' divided into two divisions for redundancy. The signals from i these sensors are conditioned by two divisionalized microprocessors. Drywell temperature is recorded by two l

pairs of divisionalized recorders in the control room. The range of the recorders is from 40'F to 440*F. These l (continued) l Brunswick Unit 1 B 3.3-78 Revision No. 3 l l

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PAM Instrumentation B 3.3.3.1 BASES LCO 7. DrvWell TemDerature (Continued) recorders are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals specifically with this portion of the instrument channel.

8. Primary Containment Isolation Valve (PCIV) Position PCIV position, a Category I variable, is provided for verification of containment integrity. In the case of PCIV position, the important information is the isolation status of the containment penetration. The LC0 requires one channel of valve position indication in the control room to be OPERABLE for each active PCIV in a containment penetration flow path, i.e., two total channels of PCIV position indication for a penetration flow path with two active valves. For containment penetrations with only one active PCIV having control room indication, Note (b) requires a single channel of valve position indication to be OPERABLE. This is sufficient to redundantly verify the isolation status of each isolable penetration via indicated status of the active valve, as applicable, and prior knowledge of passive valve or system boundary status. If a 1 penetration flow path is isolated, position indication for j the PCIV(s) in the associated penetration flow path is not i needed to determine status. Therefore, the position indication for valves in an isolated penetration flow path ;

is not required to be OPERABLE.

The PCIV position PAM instrumentation consists of position switches, associated wiring and control room indication for active PCIVs (check valves and manual valves are not required to have position indication). Therefore, the PAM Specification deals specifically with these instrument channel s.

9. Drywell and Suppression Chamber Hydroaen and 0xvoen Analyzers Drywell and suppression chamber hydrogen and oxygen analyzers are Type A and Category I instruments provided to detect high hydrogen or oxygen concentration conditions that (continued)

Brunswick Unit I B 3.3-79 Revision No. 3 l

i PAM Instrumentation B 3.3.3.1 BASES l

LC0 9. Drywell and Suppression Chamber Hydroaen and Oxvaen Analyzers (continued) !

represent a potential for containment breach. This variable !

is also important in verifying the adequacy of mitigating l actions. The drywell and suppression chamber hydrogen and l oxygen analyzers PAM instrumentation consists of two independent gas analyzer systems. Each gas analyzer system consists of a hydrogen analyzer and an oxygen analyzer. The !

analyzers are capable of determining hydrogen concentration '

in the range of 0% to 30% and oxygen concentration in the !

range of 0% to 25%. Each gas analyzer system must be l capable of sampling the drywell and the suppression chamber. ;

There are two independent recorders in the control room to :

display the.results. Therefore, the PAM Specification deals j specifically with these portions of the analyzer channels. l

10. Drywell Area Radiation Drywell area radiation is a Category I variable provided to monitor the potential of significant radiation releases and to provide release assessment for use by operators in determining the need to invoke site emergency plans. Post accident drywell area radiation levels are monjtored by four instruments, each with a range of 1 R/hr to 10 R/hr. The outputs of these channels are indicated and recorded in the control room. Therefore, the PAM Specification deals specifically with this portion of the instrument channel.

APPLICABILITY The PAM instrumentation LC0 is applicable in MODES I and 2.

These variables are related to the diagnosis and preplanned actions required to mitigate DBAs. The applicable DBAs are assumed to occur in MODES 1 and 2. In MODES 3, 4, and 5, plant conditions are such that the likelihood of an event that would require PAM instrumentation is extremely low; therefore, PAM instrumentation is not required to be OPERABLE in these MODES.

ACTIONS Note I has been added to the ACTIONS to exclude the MODE change restriction of LCO 3.0.4. This exception allows entry into the applicable MODE while relying on the ACTIONS even though the ACTIONS may eventually require plant (continued)

Brunswick Unit 1 B 3.3-80 Revision No. 3 l 1

PAM Instrumentation B 3.3.3.1 BASES ACTIONS shutdown. This exception is acceptable due to the passive (continued) function of the instruments, the operator's ability to diagnose an accident using alternative instruments and methods, and the low probability of an event requiring these instruments.

Note 2 has been provided to modify the ACTIONS related to PAH instrumentation channels. Section 1.3, Completion Times, specifies that once a Condition has been entered, subsequent divisions, subsystems, components, or variables expressed in the Condition discovered to be inoperable or not within limits, will not result in separate entry into the Condition. Section 1.3 also specifies that Required Actions of the Condition continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for !

inoperable PAM instrumentation channels provide appropriate compensatory measures for separate Functions. As such, a Note has been provided that allows separate Condition entry for each inoperable PAM Function.

A.1 When one or more Functions have one required channel that is inoperable, the required inoperable channel must be restored to OPERABLE status within 30 days. The 30 day Completion Time is based on operating experience and takes into account the remaining OPERABLE channels, the passive nature of the instrument (no critical automatic action is assumed to occur from these instruments), and the low probability of an event requiring PAM instrumentation during this interval.

B.1 If a channel has not been restored to OPERABLE status in 30 days, this Required Action specifies initiation of action in accordance with Specification 5.6.6, which ~1uires a written report to be submitted to the NRC. 111s report discusses the results of the root cause evaluation of the inoperability and identifies proposed restorative actions.

This Required Action is appropriate in lieu of a shutdown requirement, since another OPERABLE channel is monitoring the Function, and given the likelihood of plant conditions that would require information provided by this instrumentation.

(continued)

Brunswick Unit 1 B 3.3-81 Revision No. 3 l

p I PAM instrumentation D 3.3.3.1 BASES ACTIONS L.l.

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When one or more Functions have two required channels that are inoperabic (i.e., two channels inoperable in the same Function), one channel in the Function should be restored to OPERABLE status within 7 days. The Completion Time of 7 days is based on the relatively low probability of an event requiring PAM instrument operation and the availability of alternate means to obtain the required information. Continuous operation with two required i channels inoperable in a function is not acceptable because l the alternate indications may not fully meet all performance qualification requirements applied to the PAM instrumentation. Therefore, requiring restoration of one inoperable channel of the Function limits the risk that the PAM Function will be in a degraded condition should an accident occur.

U 1 This Required Action directs entry into the appropriate Condition referenced in Table 3.3.3.1-1. The applicable Condition referenced in the Table is Function dependent.

Each time an inoperable channel has not met the Required Action of Condition C and the associated Completion Time has expired,' Condition D is entered for that channel and provides for transfer to the appropriate subsequent Condition.

f.d - j For the majority of Functions in Table 3.3.3.1-1, if any Required Action and associated Completion Time of l Condition C is not met, the plant must be brought to a MODE !

in which the LCO does not apply. To achieve this status, I the plant must be brought to at least MODE 3 within ,

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The allowed Completion T!mes are reasonable, I based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

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Brunswick Unit 1 B 3.3-82 Revision No. 3 l l

I PAM Instrumentation B 3.3.3.1 BASES ACTIONS f_d (continued)

Since alternate means of monitoring primary containment area radiation are available, the Required Action is not to shut down the plant, but rather to follow the directions of Specification 5.6.6. These alternate means may be temporarily installed if the normal PAM channel cannot be restored to OPERABLE status within the allotted time. The report provided to the NRC should discuss the alternate means usca, describe the degree to which the alternate means are equivalent to the installed PAM channels, justify the areas in which they are not equivalent, and provide a schedule for restoring the normal PAM channels.

SURVEILLANCE As noted at the beginning of the SRs, the following SRs REQUIREMENTS apply to each PAM instrumentation Function in Table 3.3.3.1-1.

SR 3. 3. 3. ld Performance of the CHANNEL CHECK once every 31 days ensures that a gross failure of instrumentation has not occurred. A CHANNEL CHECK is normally a comparison of the parameter indicated on one channel against a similar parameter on other channels. It is based on the assumption that instrument channels monitoring the same parameter should read approximately the same value. Significant deviations between instrument channels could be an indication of excessive instrument drift in one of the channels or something even more serious. A CHANNEL CHECK will detect gross channel failure; thus, it is key to verifying the instrumentation continues to operate properly between each CHANNEL CALIBRATION. The high radiation instrumentation should be compared to similar plant instruments located throughout the plant.

Agreement criteria are determined by the plant staff, based on a combination of the channel instrument uncertainties, including indication and readability. If a channel is outside the criteria, it may be an indication that the sensor or the signal processing equipment has drifted outside its limit.

(continued)

Brunswick Unit 1 B 3.3-83 Revision No. 3 l I I

i a

PAM Instrumentation B 3.3.3.1 BASES SURVEILLANCE SR 3.3.3.1.1 (continued)

. REQUIREMENTS The Frequency of 31 days is based upon plant operating experience, with regard to channel OPERABILITY and drift, which demonstrates that failure of more than one channel of a given Function in any 31 day interval is rare. The CHANNEL CHECK supplements less formal, but more frequent, checks of channels during normal operational use of those displays associated with the channels required by the LCO.

SR 3.3.3.1.2 and SR 3.3.3.1.3 These SRs require a CHANNEL CALIBRATION to be performed. I CHANNEL CALIBRATION is a complete check of the instrument loop, in'cluding the sensor. The test verifies the channel responds to measured parameter with the necessary range and accuracy. For Function 9, the CHANNEL CALIBRATION shall be performed using standard gas samples containing a nominal:

a. Zero volume percent hydrogen, balance nitrogen;

b. Seven to ten volume percent hydrogen, balance nitrogen;

c. Twenty-five to thirty volume percent hydrogen, balance nitrogen;

d. Zero volume percent oxygen, balance nitrogen;

e. Seven to ten volume percent oxygen, balance nitrogen; !

and

f. Twenty to twenty-five volume percent oxygen, balance nitrogen.

For Function 10, the CHANNEL CALIBRATION shall consist of an electronic calibration of the channel, not including the detector, for range decades above 10 R/hr and a one point calibration check of the detector below 10 R/hr with an installed or portable gamma source.

The 92 day Frequency for CHANNEL CALIBRATION of the drywell and suppression chamber hydrogen and oxygen analyzers is based on operating experience. The 24 month Frequency for (continued) l Brunswick Unit 1 B 3.3-84 Revision No. 3 l 4

PAM Instrumentation B

3 3.1 BASES

SURVEILLANCE SR 3.3.3.1.2 and SR 3.3.3.1.3 (continued)

REQUIREMENTS CHANNEL CALIBRATION of all other PAM Instrumentation of Table 3.3.3.1-1 is based on operating experience and consistency with the BNP refueling cycles.

REFERENCES 1. Regulatory Guide 1.97, Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident, Revision 2, December 1980.

2. NRC_ Safety Evaluation Report, Conformance to Regulatory Guide 1.97, Rev. 2, Brunswick Steam Electric Plant, Units 1 and 2, Nay 14,1985.

3. 10 CFR 50.36(c)(2)(ii).

1 I

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i Brunswick Unit 1 B 3.3-85 Revision No. 3 1

r Primary Containment Isolation Instrumentation t

U 3.3.6.1 l

l BASES l

A)PLIC'\BLE 2.a. Reactor Vessel Water level--Low level 1 (continued)

SAFETt ANALYSES, LCO, and limit the release of fission products. The isolation of the APPL 1CABILITY primary containment on Level 1 supports actions to ensure that o?fsite dose limits of 10 CFR 100 are not exceeded.

The Reactor Vessel Water Level--Low Level 1 Function associated with isolation is implicitly assumed in the UFSAR analysis as these leakage paths are assumed to be isolated post LorA.

Reactor Vessel Water Level--Low Level 1 signals are initiated from four level transmitters that sense the difference between the pressure due to a constant column of water (reference leg) and the pressure due to the actual water level (variable leg) in the vessel. Four channels of Reactor Vessel Water Level--Low Level 1 Function are available and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

The Reactor Vessel Water Level--Low Level 1 Allowable Value was chosen to be the same as the RPS Level 1 scram Allowable Value (LCO 3.3.1.1), since isolation of these valves is not critical to orderly plant shutdown. The Allowable Value is referenced from reference level zero. Reference level zero is 367 inches above the vessel zero point.

This Function isolates the troup 2, 6, and 8 valves. I 2.b. Drywell Pressure--Hiah High drywell pressure can indicate a break in the RCPB inside the primary containment. The isolation of some of the primary containment isolation valves on high drywell pressure supports actions to ensure that offsite dose limits of 10 CFR 100 are not exceeded. The Drywell Pressure--High Function, associated with isolation of the primary containment, is implicitly assumed in the UFSAR accident analysis as these leakage paths are assumed to be isolated post LOCA.

High drywell pressure signals are initiated from pressurr transmitters that sense the pressure in the drywell. fuor channels of Drywell Pressure--High Functior, are :"-;lable and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

(contiTued)

Brunswick Unit 1 B 3.3-153 Revision No. 5 l

Primary Containment Isolation Instrumentation B 3.3.6.1 BASES APPLICABLE 3.a. 3.b., 4.a. 4.b. HPCI and RCIC Steam Line Flow-Hiah SAFETY ANALYSES, and Time Delav Relavs (continued)

LCO, and APPLICABILITY selected to prevent spurious isolation of HPCI and RCIC due to transient high steam flow during turbine starts and spurious operation during HPCI and RCIC operation.

i. The Allowable Values are chosen to be low enough to ensure L

that the trip occurs to prevent fuel damage and maintains the MSLB event as the bounding event.

These Functions isolate the Group 4 and 5 valves, as appropriate.

3.c., 4.c. HPCI and RCIC Steam Supply Line Pressure-Low The steam line low pressure function is provided so that the steam line isolation valves are automatically closed after reactor steam pressure is below that at which HPCI or RCIC can effectively operate. This closure ensures that long term containment leakage rates are within limits after a LOCA.

The HPCI and RCIC Steam Supply Line Pressure-Low signals are initiated from pressure switches (four for HPCI and four for RCIC) that are connected to the system steam line. Four channels of both HPCI and RCIC Steam Supply Line Pressure-Low Functions are available and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

The Allowable Values are selected to be below the pressure

-at which the system's turbine can effectively operate. The Allowable Values are also selected to be above the peak expected drywell pre ;sure to ensure that an elevated drywell pressure during a L(>CA does not prevent timely closure of the valves.

These Functions isolate the Group 4 and 5 valves, as appropriate.

(continued)

Brunswick Unit 1 B 3.3-156 Revision No. 4 l

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Bases Unit 1 - B 3.4 - B 3.10 Replacement Pages I

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LIST OF EFFECTIVE PAGES - BASES Paae No. Revision No. Pace No. Revision No.

Title Page N/A B 3.4-32 0 B 3.4-33 0 List of Effective Pages - Book 2 B 3.4-34 0 B 3.4-35 0 L0EP-1 7 8 3.4-36 0 i L0EP-2 3 B 3.4-37 0 L0EP-3 6 B 3.4-38 0 L0EP-4 7 B 3.4-39 0 l L0EP-5 6 B 3.4-40 0 B 3.4-41 0 1 0 B 3.4-42 0 ii 7 B 3.4-43 0 l B 3.4-44 0 B 3.4-1 0 8 3.4-45 0 B 3.4-2 0 8 3.4-46 0 B 3.4-3 1 B 3.4-47 0 B 3.4-4 1 B 3.4-48 0 B 3.4-5 1 B 3.4-49 0 B 3.4-6 1 B 3.4-7 0 B 3.5-1 0 B 3.4-8 0 B 3.5-2 0 B 3.4-9 0 B 3.5-3 0 B 3.4-10 0 8 3.5-4 0 B 3.4-11 0 8 3.5-5 0 B 3.4-12 0 B 3.5-6 0 B 3.4-13 0 0 3.5-7 0 B 3.4 0 B 3.5-8 0 B 3.4-15 0 B 3.5-9 0 8 3.4-16 0 B 3.5-10 0 B 3.4-17 0 B 3.5-11 0 B 3.4-18 0 B 3.5-12 0 B 3.4-19 0 B 3.5-13 0 B 3.4-20 0 B 3.5-14 0 B 3.4-21 0 B 3.5-15 0 B 3.4-22 0 B 3.5-16 0 B 3.4-23 0 B 3.5-17 0 B 3.4-24 0 B 3.5-18 0 8 3.4-25 0 B 3.5-19 0 i B 3.4-26 0 8 3.5-20 0 B 3.4-27 0 B 3.5-21 0 B 3.4-28 0 B 3.5-22 0 i B 3.4 29 0 B 3.5-23 0 B 3.4-30 0 B 3.5-24 0 B 3.4-31 0 B 3.5-25 0 '

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(continued)

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B 3.7-13 0 B 3.8-13 6 B 3.7-14 0 8 3.8-14 6 8 3.7-15 0 B 3.8-15 6 B 3.7-16 0 8 3.8 16 6 B 3.7-17 0 8 3.8-17 6 B 3.7-18 0 B 3.8-18 6 B 3.7-19 0 B 3.8-19 6 8 3.7-20 0 B 3.8-20 6 I B 3.7-21 0 B 3.8-21 6 l B 3.7-22 0 B 3.8-22 6 B 3.7-23 0 B 3.8-23 6 :

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I Brunswick Unit 1 L0EP-3 Revision 6 l

LIST OF EFFCCTIVE PAGES - BASES (continued)

Paae No. Revision No. Pace No. Revision No.

B 3.8-40 6 8 3.8-81 7 B 3.8-41 6 B 3.8-82 7 B 3.8-42 6 B 3.8-83 7 B 3.8-43 6 B 3.8-84 7 B 3.8-44 6 B 3.8-85 7 B 3.8-45 6 B 3.8-86 7 B 3.8-46 6 B 3.8-87 7 B 3.8-47 6 8 3.8-88 7 8 3.8-48 6 B 3.8-89 7 8 3.8-49 6 B 3.8-90 7 B 3.8-50 6 B 3.B-91 7 B 3.8-51 6 B 3.8-52 6 B 3.9-1 0 B 3.8-53 6 B 3.9-2 0 B 3.8-54 6 8 3.9-3 0 B 3.8-55 6 8 3.9-4 0 8 3.8-56 6 B 3.9-5 0 B 3.8-57 6 B 3.9-6 0 B 3.8-58 6 B 3.9-7 0 8 3.8-59 6 B 3.9-8 0 B 3.8-60 6 8 3.9-9 0 B 3.8-61 6 8 3.9-10 0 B 3.8-62 6 B 3.9-11 0 B 3.8-63 6 B 3.9-12 0 B 3.8-64 6 B 3.9-13 0 B 3.8-65. 6 B 3.9-14 0 B 3.8-66 6 B 3.9-15 0 B 3.8-67 6 8 3.9-16 0 B 3.8-68 6 B 3.0-17 0 B 3.8-69 6 8 3.9-18 0 B 3.8-70 6 8 3.9-19 0 B 3.8-71 6 B 3.9-20 0 B 3.8-72 6 B 3.9-21 0 B 3.8-73 6 B 3.9-22 0 B 3.8-74 6 B 3.9-23 0 B 3.8-75 6 8 3.9-24 0 B 3.8-76 6 8 3.9-25 0 8 3.8-77 6 8 3.9-26 0 B 3.8-78 6 8 3.9-27 0 B 3.8-79 7 8 3.9-28 0 B 3.8-80 7 8 3.9-29 0 (continued) l Brunswick Unit 1 L0EP-4 Revision 7 l

p LIST OF EFFECTIVE PAGES . BASES (continued)

Pace No. Revision No.

B 3.10 0 B 3.10-2 0 l B 3.10-3 0 B 3.10-4 0 B 3.10-5 0

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B 3.10-10 0 1 B 3.10-11 0 8 3.10-12 0 B 3.10-13 0 B 3.10 0 B 3.10-15 0 B 3.10-16 0 B 3.10-17 0 B 3.10-18 0

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! I Brunswick Unit 1 L0EP-5 Revision 6 l l

TABLE OF CONTENTS B 3.7- PLANT SYSTEMS (continued)

B 3.7.4 Control Room Air Conditioning (AC) System .... B 3.7-27

'B 3.7.5 Main Condenser Offgas .............. B 3.7-32 8 3.7.6 Main Turbine Bypass System . . . . . . . . . . . . B 3.7-35 B 3.7.7 Spent Fuel Storage Pool Water Level ....... B 3.7-39 B 3.8 ELECTRICAL POWER SYSTEMS .............. B'3.8-1 B 3.8.1 AC Sources-Operating .............. B 3.8-1 B 3.8.2: AC Sources--Shutdown . . . . . . . . . . . . . . . B 3.8-35 B 3.8.3 Diesel Fuel Oil ................. B 3.8-42 B 3.8.4 DC' Sources-Operating .............. B 3.8-50 B 3.8.5 DC Sources-Shutdown ............... B 3.8-61 B 3.8.6 Battery Cell Parameters ............. B 3.8-65 j B 3.8.7 Distribution Systems-0perating ......... B 3.8-72 B 3.8.8 Distribution Systems-Shutdown . . . . . . . . . . B 3.8-87 l B 3.91 RE' FUELING OPERATIONS . . . . . . . . . . . . . . . . . B 3.9-1 B 3.9.1 Refueling Equipment Interlocks . . .. . . . . . . . B 3.9-1 B 3.9.2 Refuel Position One-Rod-Out Interlock ...... B 3.9-5 B 3.9.3 Control Rod Position . . . . . . . . . . . . . . . B 3.9-9 8 3.9.4 Control Rod Position Indication ......... B 3.9-12 B 3.9.5 Control Rod OPERABILITY-Refueling . . . . . . . . B 3.9-16 B 3.9.6 Reactor Pressure Vessel (RPV) Water Level .... B 3.9-19 B 3.9.7 Residual Heat Removal (RHR)-High Water Level .. B 3.9-22' B 3.9.8 Residual Heat Removal '(RHR)-Low Water Level . . . B 3.9-26 8 3.10 SPECIAL OPERATIONS .._............... B 3.10-1 B 3.10.1 Ir. service Leak and Hydrostatic. Testing Operation . B 3.10-1 B 3.10.2 Reactor Mode Switch Interlock Testing ...... B 3.10-6 B 3.10.3 Single Control Rod Withdrawal-Hot Shutdown ... B 3.10-11 B 3.10.4 Single Control Rod Withdrawal-Cold Shutdown . . . B 3.10-16

'B 3.10.5 Single Control Rod Drive (CRD) Removal-Refueling -B 3.10-21 B 3.10.6 Multiple Control Rod Withdrawal-Refueling . . . . B 3.10-26 B 3.10.7 Control Rod Testing-Operating . . . . . . . . . . B 3.10-29 B 3.10.8- SHUTDOWN MARGIN (SDM) Test-Refueling ...... B 3.10-33 Brunswick Unit 1 11 Revision No. 7 1

Recirculation loops Operating B 3.4.1 l

BASES l

l 1

APPLICABLE A plant specific LOCA analysis has been performed assuming j SAFETY ANALYSES only one operating recirculation loop. This analysis has 1 (continued) demonstrated that, in the event of a LOCA caused by a pipe break in the operating recirculation loop, the Emergency Core Cooling System response will provide adequate core cooling, without the requirement to modify the APLHGR requirements (Ref. 3). However, the COLR may require APLHGR limits to restrict the peak clad temperature for a LOCA with a single recirculation loop operating below the corresponding temperature for both loops operating.

l The transient analyses of Chapter 15 of the UFSAR have also l I been performed for single recirculation loop operation (Ref. 3) and demonstrate sufficient flow coastdown characteristics to maintain fuel thermal margins during the abnormal operational transients analyzed without the requirement to modify the MCPR requirements. During single recirculation loop operation, modification to the Reactor Protection System (RPS) average power range monitor (APRM) instrument setpoints may be required to account for the different relationships between recirculation drive flow and reactor core flow by depressing a switch on the flow control trip reference cards of the APRM Flow Biased Simulated Thermal Power-High instrumentation. This manual action will adjust the flow control trip reference card to the setpoint map for single recirculation loop operation.

However, in accordance with Reference 3, no modifications to the APRM Flow Biased Simulated Thermal Power-High setpoint l are currently required. ;

1 l ilecirculation loops operating satisfies Criterion 2 of i 10 CFR 50.36(c)(2)(ii) (Ref. 4).

LC0 Two recirculation loops are normally required to be in operation with their recirculation pump speeds matched i

within the limits specified in SR 3.4.1.1 to ensure that l during a LOCA caused by a break of the piping of one

recirculation loop the assumptions of the LOCA analysis are I satisfied. Alternately, with only one recirculation loop in operation, modifications to the required APLHGR limits (LCO 3.2.1, " AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR)"), MCPR limits (LC0 3.2.2, " MINIMUM CRITICAL POWER RATIO (MCPR)"), and APRM Flow Biased Simulated Thermal Power-High setpoint (LCO 3.3.1.1), as applicable, must be applied to allow continued operation. However, based on the (continued)

{

! Brunswick Unit 1 B 3.4-3 Revision No. 1 l l

Recirculation Loops Operating B 3.4.1 BASES LC0 analyses in Reference 3, no modifications to the MCPR (continued) limits or APRM Flow Biased Simulated Thermal Power-High setpoint are required for the current operating cycle. For the current cycle, APLHGR power- and flow-dependent multipliers are required to be applied as described in the COLR.

APPLICABILITY In MODES I and 2, requirements for operation of the Reactor Coolant Recirculation System are necessary since there is considerable energy in the reactor core and the limiting design basis transients and accidents are assumed to occur.

In MODES 3, 4, and 5, the consequences of an accident are reduced and the coastdown characteristics of the recirculation loops are not important.

ACTIONS A.1 With the requirements of the LC0 not met, the recirculation loops must be restored to operation with matched ;

recirculation pump speeds within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months . A recirculation i loop is considered not in operation when the pump in that I loop is idle or when the difference in pump speeds of the ,

two recirculation pumps is greater than the match criteria.

The loop with the lower recirculation pump speed must be considered not in operation. Should a LOCA occur with one recirculation loop not in operation, the core flow coastdown and resultant core response may not be bounded by the LOCA analyses. Therefore, only a limited time is allowed to restore the inoperable loop to operating status.

Alternatively, if the single loop requirements of the LCO are applied to operating limits and RPS setpoints, as applicable, operation with only one recirculation loop would satisfy the requirements of the LCO and the initial conditions of the accident sequence.

l The 6 hour6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Completion Time is based on the low probability of an accident occurring during this time period, on a j reasonable time to complete the Required Action (i.e., reset j the applicable limits or setpoints for single recirculation !

loop operation), and on frequent core monitoring by ;

operators allowing abrupt changes in core flow conditions to -

be quickly detected.

(continued)

Brunswick Unit 1 B 3.4-4 Revision No. 1 l

7 Recirculation loops Operating B 3.4.1 1

BASES ACTIONS Ad (continued)

This Required Action does not require tripping the recirculation pump with the lowest pump speed when the pump speeds between the two recirculation pumps are greater than L the match criteria. However, in cases where large deviations from the recirculation pump speed match criteria occur, low flow or reverse flow can occur in the l recirculation loop jet pumps associated with the lower speed recirculation pump, causing vibration of the jet pumps. If l zero or reverse flow is detected, the condition should be i alleviated by changing pump speeds to re-establish forward l fl ow.

l B.1 With no recirculation loops in operation or the Required Action and associated Completion Time of Condition A not met, the plant must be brought to a MODE in which the LC0 does not apply. To achieve this status, the plant must be brought to MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . In this condition, the recirculation loops are not required to be operating because of the reduced severity of DBAs and minimal dependence on 1 l the recirculation loop coastdown characteristics. The '

I allowed Completion Time of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is reasonable, based on operating experience, to reach MODE 3 from full power conditions in an orderly manner and without challenging plant systems. l l

SURVEILLANCE SR 3.4.1.1 1 REQUIREMENTS This SR ensures the recirculation pump speeds are within the allowable match criteria. At low core flow (i.e., < 75% of rated core flow), the MCPR requirements provide larger margins to the fuel cladding integrity Safety Limit such that the potential adverse effect of early boiling transition during a LOCA is reduced. A larger difference between recirculation pump speeds can therefore be allowed when core flow is < 75% of rated core flow. The recirculation pump speed match criteria, as used in this Surveillance, conservatively corresponds to recirculation loop flow match criteria. The 10% match criterion in terms i of recirculation pump speed conservatively equates to the 5% ;

match criterion in terms of recirculation loop flow and the (continued)

Brunswick Unit 1 B 3.4-5 Revision No. 1 l

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' , Recirculation Loops Operating B 3.4.1 BASES SURVEILLANCE SR 3.4.1.1 (continued)

REQUIREMENTS 20% match criterion in terms of recirculation pump speed conservatively equates to the 10% match criterion in terms of recirculation loop flow. The generator speed associated with the recirculation pump motor-generator set may be used to measure recirculation pump speed.

The match criteria are measured in terms of the percent difference between recirculation pump speeds. If the difference between the recirculation pump speeds exceeds the match criteria..the loop with the lower recirculation pump speed is considered not in operation. The SR is not l required when both loops are not in operation since the i match criteria are meaningless during single loop or natural circulation operation. The Surveillance must be performed within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after both loops are in operation. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Frequency is consistent with the Surveillance l Frequency for jet pump OPERABILITY verification and has been shown by operating experience to be adequate to detect off normal recirculation pump speeds in a timely manner.

i REFERENCES 1. UFSAR, Section 5.4.1.3.

l

2. UFSAR, Chapter 15.

3. NEDC-31766P, Brunswick Steam Electric Plant Units 1 and 2 Single Loop Operation, February 1990.

4. 10 CFR 50.36(c)(2)(ii).

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Brunswick Unit 1 B 3.4-6 Revision No. 1 l

ri AC Sources-0perating B 3.8.1 BASES-ACTIONS- B.1 (continued)-

Required Action B.1 addresses actions to be taken in the event of inoperability of redundant required features concurrent with two offsite circuits inoperable due to one Unit 2 B0P circuit path to the downstream 4.16 kV emergency bus being inopenble and the DG associated with the downstream 4.16 kV emergency bus inoperable. When applying Required Action-B.2, the Configuration Risk Management Program described in Technical Requirements Manual 5.5.13 is required to be implemented. Condition B is inter.ded to be used for planned maintenance on the Unit 2 B0P buses and the associated 4.16 kV emergency bus (in order to perform maintenance on the 4.16 kV emergency bus, the associated DG must be rendered inoperable). Redundant required features failures consist of inoperable features that are associated with an emergency bus redundant'to the emergency bus with inoperable offsite circuits and DG. Required Action B.1 reduces the vulnerability to a loss of function. An example of inoperable redundant required feature is as follows. If one Unit I core spray subsystem becomes inoperable while planned maintenance is being performed on a Unit 2 B0P bus and the associated emergency buses, the Unit 1 RHR subsystem associated with the inoperable Unit 2 emergency bus must immediately be declared inoperable since a core spray subsystem is a redundant required feature to an RHR subsystem for the purposes of core cooling. As a result, the applicable Conditions of Specification 3.5.1, "ECCS-Operating," shall be entered and Required Actions performed. If at any time during the existence of this condition, an additional Unit 1 or Unit 2 offsite source or I DG becomes inoperable, Condition I of Unit 1 Specification 3.8.1 must be entered and the associated Required Actions performed. .

i The immediate Completion Time for Required Action B.1 is intended to ensure that all redundant required features are OPERABLE, or required features ACTIONS entered, prior to entering Condition B. This Completion Time also allows for an exception to the normal " time zero" for beginning the allowed outage time " clock". In this Required Action, the Completion Time only begins on discovery that both:

a. Two Unit 2 offsite circuits are inoperable due to one inoperable Unit 2 B0P circuit path to the downstream 4.16 kV emergency bus and the DG associated with the i downstream 4.16 kV emergency bus is inoperable; and (continued)

Brunswick' Unit 1 B 3.8-6 Revision No. 6 I i

i l

AC Sources-0perating B 3.8.1 BASES 1

1 1 1 ACTIONS B.1 (continued)

b. A redundant required feature is inoperable. '

If, at any time during the existence of this Condition, a redundant required feature subsequently becomes inoperable, this Completion Time begins to be tracked.

Condition B is modified by two notes. Note 1 only allows l this Condition to be used when the opposite unit is in MODE 4 or 5. When two offsite circuits are inoperable, due to one Unit 2 B0P circuit path and the DG associated with the downstream 4.16 kV emergency bus inoperable, while Unit 2 is in MODE 1, 2, or 3, Condition I of Unit 1 Specification 3.8.1 must be entered and the associated Required Actions performed. Note 2 prevents Condition B from being entered coincident with Condition A (i.e., the SAT or UAT shall not be inoperable coincident with a B0P l circuit path and the associated DG). The Unit 2 B0P buses l 2C and 2D can each be supplied from the Unit 2 offsite circuits (SAT and UAT). Inoperability of the Unit 2 SAT or UAT, as provided for in Condition A, would result in the loss of redundancy of offsite power to the operable B0P bus if Condition A and B were allowed to be entered coincidentally. If at any time Condition A is entered coincident with Condition B, Condition I of Unit 1 '

l Specification 3.8.1 must be entered and the associated ,

! Required Actions performed. l B.2 l The Unit 2 BOP buses 2C and 20 can each be supplied from the two Unit 2 offsite circuits (SAT and VAT). In turn, offsite power is supplied from each B0P bus to its downstream 4.16 kV emergency bus via a single circuit. Hence, an intentional outage of a B0P bus or the circuit path to its associated emergency bus (master / slave breakers and interconnecting cables) results in the loss of availability of both offsite circuits to the downstream emergency bus. ,

I The phrase " balance of plant circuit path to the downstream 4.16 kV emergency bus" as stated in Condition B refers to the B0P bus and its associated circuit path (master / slave breakers and interconnecting cables) to the downstream 4.16 kV emergency bus.

l (continued) l Brunswick Unit 1 B 3.8-7 Revision No. 6 l l

l AC Sources-0perating l B 3.8.1 BASES i

ACTIONS- B.2 (continued)

To ensure highly reliable power sources remain with one Unit 2 balance of plant circuit path to the downstream 4.16 kV emergency bus inoperable and the DG associated with the downstream 4.16 kV emergency bus inoperable, it is l necessary to verify the availability of the remaining L

offsite circuits on a more frequent basis. Since the Required Action only specifies " perform," a failure of SR 3.8.1.1 acceptance criteria does not result in the Required Action not met. However, if a second circuit fails SR 3.8.1.1, the second' offsite circuit is inoperable, and Condition E, for two or more offsite circuits inoperable, is entered.

B.3 This Required Action provides a 7 day time period to perform l planned maintenance on one of these B0P buses and the circuit path to its associated 4.16 kV emergency bus when Unit 2 is in MODE 4 or 5. During the planned maintenance of the BOP bus, the associated emergency bus and the associated DG, if a condition is discovered on these buses or the DG requiring corrective maintenance, this maintenance may be l performed within the 7 day time period of _ Required Action B.3. (If Unit 2 is in MODE 1, 2, or 3, then the Unit 2 ACTIONS of Specification 3.8.1, "AC Sources-Operating," require entry into LC0 3.0.3 for this condition.) The 7 day Completion Time takes into account the capacity and capability of the remaining AC sources and a reasonable time frame for performance of planned maintenance. This is acceptable because maintenance on each B0P bus and the circuit path to its associated emergency bus will increase the reliability of the offsite circuits to the l downstream 4.16 kV emergency buses. It should be noted that l while in this condition each of the remaining three 4.16 kV i

emergency buses will have their standby emergency source and two sources of offsite power OPERABLE. If one or both I sources of offsite power are lost to an additional 4.16 kV emergency bus then Condition E is entered.

The second Completion Time for Required Action B.3 establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet (continued) l -

1 Brunswick Unit 1 B 3.8-8 Revision No. 6 l

' AC Sources-Operating B 3.8.1 BASES 1

l ACTIONS B.3 (continued) l LC0 3.8.1.a or b. If Condition B is entered while, for:

instance, an offsite circuit is inoperable and that circuit is subsequently restored OPERABLE, the LC0 may already have l been not met for up to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . This situation could lead j to a total of 10 days from initial failure of the LC0 to l restoration of the 80P' circuit path to the downstream 4.16 kV emergency bus and DG associated with the affected 4.16 kV emergency bus. At this time, a second offsite l circuit could again become' inoperable, the B0P circuit path to the downstream 4.16 kV emergency bus and DG associated l- with the affected 4.16 kV emergency bus restored OPERABLE, and an additional 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months (for a total of 13 days) allowed l

prior to complete restoration of the LCO. The 10 day l

Con,? l etion Time provides a limit on the time allowed in a specified condition after discovery of failure to meet LC0 3.8.1.a or b. This limit is considered reasonable for situations in which Condition 3 and Condition C or D are entered concurrently. The "AND" connector between the.7 day and 10 day Completion Time means that both Completion Times apply simultaneously, and the more restrictive must be met.

As in Required Action B.1, the second Completion Time allows for an exception to the normal " time zero" for beginning the allowed outage time " clock". This exception results'in i establishing the " time zero" at the time that LC0 3.8.1.a '

or b was initially not met, instead of the time that Condition B was entered.

C.1 1 To ensure a highly reliable power source remains with one offsite circuit inoperable, it is necessary to verify the ,

. availability of the remaining offsite circuits on a more frequent basis. Since the Required Action only specifies ;

" perform," a failure of SR 3.8.1.1 acceptance criteria does ;

not result in a Required Action not met. However, if a l second circuit fails SR 3.8.1.1, the second offsite circuit ,

is inoperable, and Condition E, for two or more offsite I circuits inoperable, is entered.

(continued)

Brunswick Unit 1 B 3.8-9 Revision No. 6 1.

l AC Sources-0perating B 3.8.1 l

BASES-ACTIONS' C.2 (continued)

Required Action C.2, which only applies if one 4.16 kV )

emergency bus cannot be powered from an offsite source, is intended to provide assurance that an event with a coincident single failure of the associated DG doss not l result in a complete loss of safety function of reitical I systems.- These features (e.g., system, subsystan, division, component, or device) are designed with redune: ant safety related 4.16 kV emergency buses. Redundant required feature failures consist of inoperable features associated with an l emergency bus redundant to the emergency bus that has no I l offsite power.

The Completion Time fo'r Required Action C.2 is intended to 1 allow time for the operator to evaluate and repair any 1 l discovered inoperabilities. This Completion Time also .l allows an exception to the normal " time zero" for beginning the allowed outage time " clock." In this Required Action the Completion Time only begins on discovery that both:

a. A 4.16 kV emergency bus has no offsite power supplying its loads; and

b. A redundant required feature on another emergency bus

is inoperable.

If, at any time during the existence of this Condition (one offsite circuit inoperable) a redundant required feature subsequently becomes inoperable, this Completion Time would begin to be tracked.

Discovering no offsite power to one 4.16 kV emergency bus of l the onsite Class IE Power Distribution System coincident. l with one or more inoperable required support or supported features, or.both, that are associated with any other i emergency bus that has offsite power, results in starting l the Completion Times for the Required Action. Twenty-four hours is acceptable because it minimizes risk while allowing time for restoration before the unit is subjected to transients associated with shutdown.

(continued) ,

I Brunswick Unit'l B 3.8-10 Revision No. 6 I b

AC Sources-0perating B 3.8.1 l

BASES 1

ACTIONS C.2 (continued) I l The remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to the onsite Class lE Distribution System. Thus, on a component basis, single failure protection may have been lost for the required feature's function; however, function is not lost. The.

24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time takes into account the component OPERABILITY of the redundant counterpart to the inoperable required feature. Additionally, the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time takes into account the capacity and capab;1ity of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

C.3 l l

According to Regulatory Guide 1.93 (Ref. 9), operation may I

continue in Condition C for a period that should not exceed 1 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . With one offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the plant safety systems. In this condition, however, the remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to the onsite Class IE Distribution System.

The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

The second Completion Time for Required Action C.3 l establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet l

LC0 3.8.1.a or b. If Condition C is entered while, for I instance, a DG is inoperable, and that DG is subsenuently returned OPERABLE, the LC0 may already have been not met for up to 7 days. This situation could lead to a total of 10 days, 'since initial failure to meet the LCO, to restore l the.offsite circuit. At this time, a DG could again become inoperable, the circuit restored OPERABLE, and an additional 7-days (for a total of 17 days) allowed prior to complete ',

restoration of the LCO. The 10 day Completion Time provides j (continued) !

l Brunswick Unit l' B 3.8-11 Revision No. 6 i

AC Sources-Operating B 3.8.1 BASES ACTIONS C.3 (continued) i a limit on the time allowed in a specified condition after discovery of failure to meet LC0 3.8.1.a or b. This limit is considered reasonable for situations in which Conditions C and D are entered concurrently. The "AND" l connector between the 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months and 10 day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.

As in Required Action C.2, the Completion Time allows for an i exception to the normal " time zero" for beginning the allowed outage time " clock." This exception results in establishing the " time zero" at the time LC0 3.8.1.a or b was initially not met, instead of at the time that ,

Condition C was entered. I i D.1 l To ensure a highly reliable power source remains with one DG inoperable, it is necessary to verify the availability of the offsite circuits on a more frequent basis. Since the Required Action only specifies " perform," a failure to meet SR 3.8.1.1 acceptance criteria does not result in a Required Action being not met. However, if a circuit fails to pass SR 3.8.1.1, it is inoperable. Upon offsite circuit inoperability, additional Conditions must then be entered.

D.2 Required Action D.2 is intended to provide assurance that a loss of offsite power, during the period that a DG is inoperable, does not result in a complete loss of safety function of critical systems. These features are designed to be powered from redundant safety related 4.16 kV emergency buses (i.e., single division systems are not included). Redundant required feature failures consist of inoperable features associated with an emergency bus redundant to the emergency bus that has an inoperable DG.

(continued)

Brunswick Unit 1 B 3.8-12 Revision No. 6 l 1

4

l l- AC Sources-0perating l B 3.8.1

' BASES ACTIONS D.2 (continued) l The Completion Time is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal ;

" time zero" for beginning the allowed outage time " clock."

In this Required Action the Completion Time only begins on discovery _that both:

l a. An l inoperable DG exists; -and

b. A redundant required feature on another emergency bus i is inoperable.

l If, at any time during the existence of this Condition (one DG inoperable), a required redundant feature subsequently-becomes inoperable, this Completion Time begins to be tracked.

Discovering one DG inoperable coincident with one or more inoperable required support or supported features, or both, that are associated with the OPERABLE DGs results in starting the Completion Time for the Required Action. Four hours from the discovery of these events existing concurrently is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to-transients associated with shutdown.

1 The remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. Thus, on a component basis, single failure protection for the required feature's function may have been lost; however, function has not been lost. The 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Completion Time takes into account the component OPERABILITY of the redundant counterpart to the inoperable l required feature. Additionally, the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Completion Time !

l takes into account the capacity and capability of the !

remaining AC sources, a reasonable time for repairs, and the ;

low probability of a DBA occurring during this period.

l (continued) 4 L Brunswick Unit 1 B 3.8-13 Revision No. 6 i g

r AC Sources-Operating B 3.8.1 BASES ACTIONS D.3.1 and D.3.2 (continued)

Required Action D.3.1 provides an allowance to avoid unnecessary testing of OPERABLE DGs. If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DGs, SR 3.8.1.2 does not have to be performed. If the cause of inoperability exists on other DG(s), they are declared inoperable upon discovery, and Condition G or I of LC0 3.8.1 is entered, as applicable. I Once the failure is repaired, and the common cause failure no longer exists, Required Action D.3.1 is satisfied. If I the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of i SR 3.8.1.2 suffices to provide assurance of continued l OPERABILITY of those DGs.

In the event the inoperable DG is restored to OPERABLE status prior to completing either D.3.1 or D.3.2 (i.e., the I inoperable DG has been restored to OPERABLE status but it i has not yet been determined if the cause of the inoperability is common to the other OPERABLE DGs), the CP&L Corrective Action Program (CAP) will continue to evaluate the common cause possibility. This continued evaluation, l however, is no longer required under the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months constraint imposed.while in Condition D. I According to Generic Letter 84-15 (Ref. 10), 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is a reasonable time to confirm that the OPERABLE DGs are not affected by the same problem as the inoperable DG. ,

0.4 1 The 4.16 kV emergency bus design is sufficient to allow operation to continue in Condition D for a period that should not exceed 7 days. In Condition D, the remaining 0PERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class lE Distribution System.

The 7 day Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

(continued)

Brunswick Unit 1 B 3.8-14 Revision No. 6 1

i AC Sources-0perating B 3.8.1 BASES ACTIONS D.4 (continued) !

The second Completion Time for Required Action D.4 establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable !

during any single contiguous occurrence of failing to meet LC0 3.8.1.a or b. If Condition D is entered while, for I instance, an offsite circuit is inoperable and that circuit is subsequently restored OPERABLE, the LC0 may. already have been not met for up to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . This situation could lead to a total- of 10 days, since initial failure of the LCO, to restore the DG. At this time, an offsite circuit could again become inoperable, the DG restored OPERABLE, and an additional 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months (for a total of 13 days) allowed prior to complete restoration of the LCO. The 10 day Completion Time provides a limit on the time allowed in a specified condition after discovery of failure to meet LCO 3.8.1.a or b. This limit is considered reasonable for situations in which Conditions C and D are entered concurrently. The l "AND" connector between the 7 day and 10 day Completion Times means that both Completion Times apply simultaneously, and the more restrictive must be met.

As in Required Action 0.2, the Completion Time allows for an l exception to the normal " time zero" for beginning the allowed outage time " clock." This exception results in establishing the " time zero" at the time that LC0 3.8.1.a or b was initially not met, instead of the time that Condition D was entered. I E.1 and E.2 Required Action E.1 addresses actions to be taken in the event of inoperability of redundant required features concurrent with inoperability of two or more offsite circuits. Required Action E.1 reduces the vulnerability to I a loss of function. The Completion Time for taking these actions is reduced to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months from that allowed with one 4.16 kV emergency bus without offsite power (Required Action C.2). The rationale for the reduction to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is I that Regulatory Guide 1.93 (Ref. 9) allows a Completion Time of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for two offsite circuits inoperable, based upon the assumption that two complete safety divisions are OPERABLE. While this Action allows more than two circuits (continued) i I

Brunswick Unit 1 B 3.8-15 Revision No. 6 l j l

a

AC Sources-Operating B 3.8.1 l

BASES i

ACTIONS E.1 and E.2 (continued) l l

to be inoperable, Regulatory Guide 1.93 (Ref. 9) assumes q only two circuits are required by the LCO, and a loss of '

l those two circuits results in a total loss of offsite power to the Class IE Electrical Power Distribution System. Thus, i

I with the BNP electrical design, a loss of the four offsite l circuits results in the same condition assumed in Regulatory Guide 1.93 (Ref. 9). When a concurrent redundant required feature failure exists, this assumption is not the case, and

a shorter Completion Time of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is appropriate. These features are designed with redundant safety related 4.16 kV emergency buses, (i.e., single division systems are not included in the list). Redundant required feature failures consist of any of these features that are inoperable because any inoperability is on an emergency bus redundant to an emergency bus with inoperable offsite circuits.

l The Completion Time for Required Action E.1 is intended to l l

allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." In this Required Action, the Completion Time only begins on discovery that l both:

a. Two or more offsite circuits are inoperable; and

b. A redundant required feature is inoperable.

If, at any time during the existence of this condition (any combination of two or more Unit 1 and 2 offsite circuits inoperable), a redundant required fcaure subsequently becomes inoperable, this Completion Time begins to be tracked.

According to Regulatory Guide 1.93 (Ref. 9), operation may continue in Condition E for a period that shculd not exceed I 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . This level of degradation means that the offsite electrical power system may not have the capability to effect a safe shutdown and to mitigate the effects of an accident; however, the onsite AC' sources have not been degraded. This level of degradation generally corresponds to a total loss of the immediately accessible offsite power sources.

(continued) l l

Brunswick Unit 1 B 3.8-16 Revision No. 6 l l

h AC Sources-0perating B 3.8.1 j BASES ACTIONS E.1 and E.2 (continued) l Because of the normally high availability of the offsite sources, this level of degradation may appear to be more i severe than other combinations of two AC sources inoperable j that involve one or more DGs inoperable. However, two factors tend to decrease the severity of this degradation level:

a. The configuration of the redundant AC electrical power system that remains available is not susceptible to a single bus or switching failure; and

b. The time required to detect and restore an unavailable offsite power source is generally much less than that required to detect and restore an unavailable onsite AC source.

With two or more of the offsite circuits inoperable, sufficient onsite AC sources are available to maintain the unit in a safe shutdown condition in the event of a DBA or transient. In fact, a simultaneous loss of offsite AC sources, a LOCA, and a worst case single failure were postulated as a part of the design basis in the safety analysis. Thus, the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time provides a period of time to effect restoration of all but one of the offsite circuits commensurate with the importance of maintaining an AC electrical power system capable of meeting its design criteria.

j i

According to Regulatory Guide 1.93 (Ref. 9), with the !

available offsite AC sources two less than required by the !

LCO, operation may continue for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If all offsite ;

sources are restored within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , unrestricted operation '

may continue. If all but one offsite source is restored !

within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , power operation continues in accordance with Condition A or C, as applicable. I F.1 and F.2 l Pursuant to LCO 3.0.6, the Distribution System-Operating ACTIONS would not be entered even if all AC sources to it were inoperable, resulting in de-energization. Therefore, the Required Actions of Condition F are modified by a Note 1 (continued)

Brunswick Unit 1 B 3.8-17 Revision No. 6 l

AC Sources-0perating B 3.8.1 BASES ACTIONS F.1 and F.2 (continued) to indicate that when Condition F is entered with no AC source to any 4.16 kV emergency bus, ACTIONS for LC0 3.8.7,

" Distribution Systems-Operating," must be immediately entered. .This allows Condition F to provide requirements I for the loss of an offsite circuit and one DG without regard to whether an emergency bus is de-energized. LC0 3.8.7 provides the appropriate restrictions for a de-energized emergency bus.

1 According to Regulatory Guide 1.93 (Ref. 9), operation may j continue in Condition F for a period that should not exceed 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . In Condition F, individual redundancy is lost in both the offsite electrical power system and the onsite AC '

electrical power system. Since power system redundancy is provided by two diverse sources of power, however, the reliability of the power systems in this Condition may appear higher than that in Condition E (loss of two or more I offsite circuits). This difference in reliability is offset by the susceptibility of this power system configuration to a single bus or switching failure. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

G.1 l With two or more DGs inoperable and an assumed loss of offsite electrical power, insufficient standby AC sources are available to power the minimum required ESF functions.

Since the offsite electrical power system is the only source of AC power for the majority of ESF equipment at this level of degradation, the risk associated with continued operation for a very short time could be less than that associated l with an immediate controlled shutdown. (The immediate l shutdown could cause grid instability, which could result in i i a total loss of AC power.) Since any inadvertent unit l generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation i is severely restricted. The intent here is to avoid the

risk associated with an immediate controlled shutdown and to minimize the risk associated with this le/el of degradation.

l l (continued) l l

Brunswick Unit 1 B 3.8-i8 Revision No. 6 I

AC Sources-0perating B 3.8.1 BASES ACTIONS G.1 (continued) l According to Regulatory Guide 1.93 (Ref. 9), with two or more DGs inoperable, operation may continue for a period that should not exceed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . While this Action allows more than two DGs to be inoperable, Regulatory Guide 1.93 (Ref. 9) assumes only two DGs are required by the LCO, and a loss of those two DGs results in a total loss of onsite power to the Class lE Electrical Power Distribution System.

Thus, with the BNP electrical design, a loss of the four DGs results in the same condition assumed in Regulatory Guide 1.93 (Ref. 9).

H.1 and H.2 l If the inoperable. AC electrical power sources cannot be restored to OPERABLE status within the associated Completion

-Time, the unit must be brought to a MODE in which the LC0 does not apply. To achieve this status,_the unit must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

i I.1 !

I Condition I corresponds to a level of degradation in which all redundancy in the AC electrical power supplies has been lost. At this severely degraded level, any further losses in the AC electrical power system may cause a loss of function. Therefore, no additional time is justified for continued operation. The unit is required by LC0 3.0.3 to commence a controlled shutdown.

SURVEILLANCE The AC sources are designed to permit inspection and REQUIREMENTS testing of all important areas and features, especially those that have a standby function, in accordance with UFSAR !

Sections 8.2 and 8.3 (Ref. 2). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions). The SRs for (continued)

Brunswick Unit 1 B 3 8-19 Revision No. 6 l

AC Sources-0perating B 3.8.1 BASES SURVEILLANCE demonstrating the OPERABILITY of the DGs are consistent with REQUIREMENTS the recommendations of Safety Guide 9 (Ref 5), Regulatory (continued) Guide 1.9 (Ref.11), and Regulatory Guide 1.137 (Ref.12),

as addressed in the UFSAR.

Where the SRs discussed herein specify voltage and frequency tolerances, the following summary is applicable. The '

minimum steady state output voltage of 3750 V is derived from the recommendations found in Safety Guide 9 (Ref. 5) and bounds the minimum steady state output voltage criteria of 3621 V associated with the 4.16 kV emergency buses analyzed in the AC Auxiliary Electrical Distribution System Study.. This value (3621 V) allows for voltage drop to the terminals of 4000 V motors whose minimum operating voltage is specified as 3600 V. It also allows for voltage drops to motors and other equipment down through the 480 V level where minimum operating voltage is also usually specified as 90% of name plate rating. The specified maximum steady state output voltage of 4300 V ensures the maximum operating voltage at the safety related 480 V substations is no more than the maximum rated steady state voltage criteria for the 480 V motor control centers. The maximum steady state output voltage was determined taking into consideration the voltage drop between the DGs and the 4.16 kV emergency buses and a 5% voltage boost at the 480 V substation transformers.

This maximum steady state output voltage also ensures that for a lightly loaded distribution system, the voltage at the terminals of 4000 V motors is no more than the maximum rated steady state operating voltage. The specified minimum and maximum frequencies of the DG are 58.8 Hz and 61.2 Hz, respectively. These values are equal to i 2% of the 60 Hz nominal frequency and are derived from the recommendations found in Safety Guide 9 (Ref. 5).

SR 3.8.1.1 .

This SR ensures proper circuit continuity for the offsite AC electrical power supply to the onsite distribution-network and availability of offsite AC electrical power. The breaker alignment verifies that each breaker is in its correct position to ensure that distribution buses and loads are connected to their preferred power source and that I appropriate independence of offsite circuits is maintained.

The 7 day Frequency is adequate since breaker position is not likely to change without the operator being aware of it and because its status is displayed in the control room.

(continued)

Brunswick Unit 1 B 3.8-20 Revision No. 6 l

1 l

AC Sources-0perating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.7 REQUIREMENTS (continued) These SRs help to ensure the. availability of the standby electrical power supply to mitigate DBAs and transients and maintain the unit in a safe shutdown condition.

To minimize the wear on moving. parts that do not get lubricated when the engine is not running, these SRs have been modified by a Note (Note 1 for SR 3.8.1.2 and i SR 3.8.1.7) to indicate that all DG starts for these Surveillances may be preceded by an engine prelube period.

l For the purposes of this testing, the DGs are started from standby conditions. Standby conditions for a DG mean that the diesel engine coolant and oil are being continuously l circulated and temperature is being maintained.

In order to reduce stress and wear on diesel engines, some manufacturers recommend a modified start in which the starting speed of DGs is limited, warmup is-limited to this lower speed, and the DGs are gradually accelerated to synchronous speed prior to loading. These start procedures are the intent of Note 2 of SR 3.8.1.2.

l l SR 3.8.1.7 requires that, at a 184 day Frequency, the DG starts from standby conditions and achieves required voltage

.and frequency within 10 seconds. The minimum voltage and frequency stated in the SR are those necessary to ensure the DG can accept DBA loading while. maintaining acceptable voltage and frequency levels. Stable operation at the nominal' voltage and frequency values is also essential to establishing DG OPERABILITY, but a time constraint is not imposed. This is because a typical DG will experience a period of voltage and frequency oscillations prior to reaching steady state operation if these oscillations are not dampened by load application. This period may be

. extended beyond the 10 second acceptance criteria and could be cause for failing the SR. In lieu of a time constraint l in the SR,-BNP will monitor and trend the actual time to reach steady state operation as a means of ensuring there is ,

l no voltage regulator or governor degradation which could I cause a DG to become inoperable. The 10 second start I requirement. supports and is conservative with respect to the l assumptions in the design basis LOCA analysis of UFSAR, !

Section 6.3 (Ref. 6). The 10 second start requirement is l (continued) ;

1 Brunswick Unit 1 B 3.8-21 Revision No. 6 l l

L

h AC Sources-Operating B 3.8.1

- BASES

-5URVEILLANCE SR 3.8.1.2 and SR 3.8.1.7 (continued) i REQUIREMENTS l not applicable to SR 3.8.1.2 (see Note 2 of SR 3.8.1.2),

l. when a modified start procedure as described above is used.

If a modified start is not used, the 10 second start requirement of SR 3.8 4.7 applies.

To minimize testing or the DGs, Note 3 to SR 3.8.1.2 and Note 2 to SR 3.8.1.7 allow:a single test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by performing the test on either unit. ;If the DG fails one _of these Surveillances, the DG should be considered inoperable on both units, unless the cause of the failure can be directly related to only one unit.

The 31 day Frequency for SR 3.8.1.2.is consistent with Regulatory Guide 1.9 (Ref. 11). The 184 day Frequency for SR 3.8.1.7 is'a reduction in cold testing consistent with Generic Letter 84-15 (Ref. 10). These Frequencies provide adequate assurance of DG OPERABILITY, while minimizing

' degradation resulting from testing.

I SR 3.8.1.3 This Surveillance verifies that the DGs are capable of synchronizing and accepting a load approximately equivalent to the continuous rating of the DGs. A minimum run time of 60 minutes is required to stabilize engine temperatures, while minimizing the time that the DG is connected to the offsite source.

Although no power factor requirements are established by this SR, the DG is normally operated at a power factor between 0.8 lagging and 1.0. The 0.8 value is the design rating of the machine, while 1.0 is the generator design limitation which if exceeded could lead to generator

! instability while in parallel with the offsite circuit. The l load band is provided to avoid routine overloading of the DG. Routine overloading may result in more frequent teardown inspections in order to maintain DG OPERABILITY.

l The 31 day Frequency for this Surveillance is consistent with Regulatory Guide 1.9 (Ref. 11).

(continued)

Brunswick Unit 1 B 3.8-22 Revision No. 6 1

F AC Sources-0perating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.3 (continued)

REQUIREMENTS Note 1 modifies this Surveillance to indicate that diesel engine runs for this Surveillance may include gradual loading so that mechanical stress and wear on the diesel engine are minimized.

Note 2 modifies this Surveillance by stating that momentary transients because of changing bus loads do not invalidate this test. Similarly, momentary power factor transients outside the range normally used during the performance of this Surveillance do not invalidate the test.

Note 3 indicates that this Surveillance should be conducted on only one DG at a time in order to avoid common cause failures that might result from offsite circuit or grid perturbations.

Note 4 stipulates a prerequisite requirement for performance of this SR. A successful DG start must precede this test to credit satisfactory performance. l To minimize testing of the DGs, Note 5 allows a single test (instead of two tests, one for each unit) to satisfy the 1 requirements for both units. This is allowed since the main j purpose of the Surveillance can be met by performing the '

test on either unit. If the DG fails one of these Surveillances, the DG should be considered inoperable on i both units, unless the cause of the failure can be directly ;

related to only one unit.

SR 3.8.1.4 '

This SR provides verification that the level of fuel oil in )

the engine mounted tank is slightly below the level at which the backup fuel oil transfer pump automatically starts. The level is expressed as an equivalent volume in gallons, and is selected to ensure adequate fuel oil for approximately 30 minutes of DG operation at rated load. This SR may be satisfied by verifying the absence of the associated low level alarm.

The 31 day Frequency is adequate to ensure that a sufficient supply of fuel oil is available, since low level alarms are provided and facility operators would be aware of any large uses of fuel oil during this period.

(continued)

Brunswick Unit 1 B 3.8-23 Revision No. 6 I

e 'l 1

AC Sources-0perating B 3.8.1 BASES.

SURVEILLANCE SR 3.8.1.5 REQUIREMENTS I

(continued) Microbiological fouling is a major cause of fuel oil degradation. There are numerous bacteria that can grow in fuel oil and cause fouling, but all must have a water environment in order to survive. Removal of water from the engine mounted tanks once every 31 days eliminates the necessary environment for bacterial _ survival. This is the j most effective means of controlling microbiological fouling.

In addition, it eliminates the potential for water entrainment in the fuel oil during DG operation. Water may l come from any of several sources, including condensation, rain water, contaminated fuel oil, and breakdown of the fuel oil by bacteria. Frequent checking for and removal of l

accumulated water minimizes fouling and provides data l regarding the watertight integrity of the fuel oil system.

The Surveillance Frequencies are established by Regulatory Guide 1.137 (Ref. 12). This SR is for preventive maintenance. The presence of water does not necessarily represent a failure of this SR provided that accumulated water is removed during performance of this Surveillance.

Removal of accumulated water may be accomplished by draining a portion of fuel oil from the engine mounted fuel oil tank to the day fuel oil storage tank and draining any accumulated water from the day fuel oil storage tank in accordance with SR 3.8.3.3. The draining evolution will continue until accumulated water is verified to be removed from the engine mounted fuel oil tank.

1 SR 3.8.1.6 l

l This Surveillance demonstrates that each required fuel oil i

transfer pump operates and transfers fuel oil from its l associated storage tank to its associated day tank. It is i required to support continuous operation of standby power sources. This Surveillance provides assurance that the fuel oil transfer pump is OPERABLE, the fuel oil piping system is intact, the fuel delivery piping is not obstructed, and the controls and control systems for fuel transfer systems are OPERABLE.

(continued)

Brunswick Unit 1 B 3.8-24 Revision No. 6 l

[

L L

i AC Sources-0perating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.6 (continued)

REQUIREMENTS The Frequency for this SR is consistent with the Frequency for testing the DGs in SR 3.8.1.3. DG operation for SR 3.8.1.3 is normally long enough that fuel oil level in the engine mounted tank will be reduced to the point where the fuel oil transfer pump automatically starts to restore fuel oil level in the engine mounted tank.

SR 3.8.1.8 Transfer of each 4.16 kV emergency bus power supply from the '

normal circuit to the preferred offsite circuit and from the preferred offsite circuit to the alternate offsite circuit demonstrates the OPERABILITY of the offsite circuit distribution network to power the shutdown loads. In lieu of actually initiating an automatic circuit transfer, testing that adequately shows the capability of the transfer is acceptable. The automatic transfer testing may include any series of sequential,. overlapping, or total steps so that the entire transfer sequence is verified. The 24 month "requency of the Surveillance is based on engineering judgment taking into consideration the plant conditions required to perform the Surveillance, and is intended to be consistent with expected fuel cycle lengths. Operating experience has demonstrated that these components will pass the SR when performed on the 24 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

This SR is modified by three Notes. The reason for Note 1 is that, during operation with the reactor critical, performance of SR 3.8.1.8.a, verification of automatic transfer capability of the unit power supply from the normal circuit to the preferred offsite circuit, could cause perturbations to the electrical distribution systems that could challenge continued steady state operation and, as a result, plant safety systems. Note 1 is not applicable to SR 3.8.1.8.b, verification of manual transfer of the unit power supply from the preferred offsite circuit to the alternate offsite circuit, since this evolution does not cause perturbations of the electrical distribution systems.

Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, both units' offsite circuits are required to be OPERABLE to (continued)

Brunswick Unit 1 B 3.8-25 Revision No. 6 I

AC Sources-0perating B 3.8.1 BASES l SURVEILLANCE SR 3.8.1.8 (continued) i REQUIREMENTS supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the consequences of a potential perturbation.to the electrical distribution systems during the performance of this Surveillance, while l at.the same time avoiding the need for a shutdown of both units to perform this Surveillance, Note 1 only precludes satisfying this Surveillance Requirement for the Unit 1 offsite circuits when Unit 1 is in MODE 1 or 2. During the performance of this Surveillance with Unit I not in MODE l-E or 2 and with Unit 2 in MODE 1, 2, or 3; the applicable l ACTIONS of the Unit I and Unit 2 Technical Specifications must be entered if a Unit 1 offsite circuit is rendered inoperable by the performance of this Surveillance. Credit may be taken for unplanned events that satisfy this SR. As stated in Note 2, automatic transfer capability to the SAT is not required to be met when the associated 4.16 kV emergency buses are powered from the preferred offsite circuit. This is acceptable since the automatic transfer capability function has been satisfied in this condition.

To minimize testing, Note 3 allows a single test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by performing the test on a single unit. If an offsite circuit fails one of the Surveillances, the offsite circuit should be considered inoperable for both units.

SR 3.8.1.9 Each DG is provided with an engine oversped trip to prevent damage to the engine. Recovery from t'.s transient caused by the loss of a large load could cause diesel engine overspeed, which, if excessive, might result in a trip of the engine. This SurveillaNe demonstrates the DG capability to reject the largest single load without tripping. The largest single load for each DG is a core spray pump (1250 hp). This Surveillance may be accomplished by:

a. Tripping the DG output breaker with the DG carrying greater than or equal to its associated core spray pump while paralleled to offsite power, or while solely supplying the bus; or (continued)

Brunswick Unit 1 B 3.8 26 Revision No. 6 i

AC Sources-Operating B 3.8.1 BASES.

SURVEILLANCE- SR 3.8.1.9 (continued) ,

REQUIREMENTS

b. Tripping its associated core spray pump with the DG solely supplying the bus.

The load rejection test is acceptable if the increase in diesel speed does not exceed the overspeed trip setpoint.

The 24 month Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref. 11).

This SR is modified by three Notes. The reason for Note 1 is that, during operation with the reactor critical, performance of this SR could cause perturbations to the electrical distribution systems that could challenge continued steady state operation and, as a result, plant safety systems. Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units'I and 2, all four DGs are required to be OPERABLE to supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the consequences of a potential perturbation to the electrical distribution systems during the performance of this Surveillance, while at the same time avoiding the need to i

shutdown both units to perform this Surveillance, Note 1 only precludes satisfying this Surveillance Requirement for DG 1 and DG 2 when Unit 1 is in MODE 1, 2, or 3. During the performance of this Surveillance with Unit I not in MODE 1, 2, or 3 and with Unit 2 in MODE 1, 2, or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications must be entered if DG 1 or DG 2 is rendered inoperable by the performance of this Surveillance. Credit may be taken for unplanned events that satisfy this SR. In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, Hote 2 requires that, if synchronized to offsite power, testing must be performed using a power factor s 0.9. This power l

factor is chosen to be representative of the actual design basis inductive loading that the DG would experience. To minimize testing of the DGs, Note 3 allows a single test (instead of two tests, one for each unit) to. satisfy the requirements for both units. This is allowed since the main l purpose of the Surveillance can be met by performing the 1 test on either unit. If the DG fails one of these l

Surveillances, the DG should be considered inoperable on both units, unless the cause of the failure can be directly related to only one unit.

(continued) 1 l

l Brunswick Unit 1- B 3,8-27 Revision No. 6 1

1 AC Sources-0perating B 3.8.1 l

BASES SURVEILLANCE SR 3.8.1.10 REQUIREMENTS (continued) Consistent with Regulatory Guide 1.9 (Ref. 11), paragraph C.2.2.12, this Surveillance demonstrates that DG non-critical protective functions (e.g., high Jacket water l temperature) are. bypassed on an ECCS initiation test signal

l. and critical protective functions (engine overspeed, generator differential overcurrent, low lubricating oil pressure, reverse power, loss of field, and phase overcurrent-voltage restrained) trip the DG to avert substantial damage to the DG unit. The non-critical trips

are bypassed during DBAs and provide an alarm on an abnormal l engine condition. This' alarm provides the operator with sufficient. time to react appropriately. The DG availability l to mitigate the DBA is more critical than protecting the engine against minor problems that are not immediately detrimental to emergency operation of the DG.

The 24 month Frequency is based on engineering judgment, takes into consideration plant conditions required to perform the Surveillance, and is intended to be consistent with expected fuel cycle lengths. Operating experience has demonstrated that these components will pass the SR when ,

performed at the 24 month Frequency. Therefcce, the J Frequency was concluded to be acceptable from a reliability standpoint.

The SR is modified by a Note. To minimize testing of the DGs, the Note allows a single test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by performing the test on either unit. If the DG fails one of these Surveillances, the DG l should be considered inoperable on both units, unless the cause of the failure can be directly related to only one unit.

SR 3.8.1.11 Brunswick Nuclear Plant performs a 60 minute run greater than or equal to the continuous rating (3500 kW) which ,

, bounds ~the maximum expected post-accident DG loading. The !

l DG starts for this Surveillance can be performed either from (continued)

I i

i Brunswick Unit 1 B 3.8-28 Revision No. 6 1 1

1

)

AC Sources-0perating B 3.8.1 BASES SURVEILLANCE .S_3_3. 8.1. l l (continued)

REQUIREMENTS standby or hot conditions. The provisions for prelube and warmup, discussed in the Bases for SR 3.8.1.2, and for gradual loading, discussed in the Bases for SR 3.8.1.3, are applicable to this SR.

In order to ensure that the DG is tested under load conditions that are as close to design conditions as 1 possible, testing must be performed using a power factor '

s 0.9. This power factor is chosen to be representative of the actual design basis inductive loading that the ')G could experience. A load band is provided to avoid routiste overloading of the DG. Routine overloading may result. in more frequent teardown inspections in order to maintain DG OPERABILITY.

The 24 month Frequency is consistent with the i recommendations of Regulatory Guide 1.9 (Ref.11), Table 1; takes into consideration plant conditions required to perform the Surveillance; and is intended to be consistent with expected fuel cycle lengths.

This Surveillance has been modified by two Notes. Note 1.

states that momentary transients due to changing bus loads do not invalidate this test. Similarly, momentary power factor transients above the limit do not invalidate the test. To minimize testing of the DGs, Note 2 allows a single test (instead of two tests,~one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by.

performing the test on either unit. If the DG fails one of these Surveillances, the DG should be considered inoperable on both units, unless the cause-of the failure can be directly related to only one unit.

SR 3.8.1.12 Consistent with Regulatory Guide 1.9 (Ref.11), paragraph C.2.2.13, demonstration of the test mode override feature ensures that the DG availability under accident conditions is not compromised as the result of testing. Interlocks to the LOCA sensing circuits cause the DG to automatically reset to ready-to-load operation if an ECCS initiation (continued)

Brunswick Unit I- B 3.8-29 Revision No. 6 I i

l L.

, AC Sources-Operating

> B 3.8.1 BASES I

l' SURVEILLANCE SR 3.8.1.12 (continued) i

-REQUIREMENTS' signal-is received during operation in the test mode.

Ready-to-load operation is defined as the DG running at <

rated speed and voltage with the DG output breaker open.

These provisions for automatic switchover are required by IEEE-308 (Ref. 13), paragraph 6.2.4(6).

In lieuof actually returning the DG to ready-to-load !

status, testing that adequately shows the capability of the j DG to perform this function is acceptable. This testing may J l . include any series of sequential, overlapping, or total steps so that the entire sequence is verified.

The 24 month Frequency is consistent with the recommendations of Regulatory Guide 1.9 (Ref.11), Table 1;

, takes into consideration plant conditions required to

! perform the Surveillance; and is intended to be consistent

.with expected fuel cycle lengths. .

This SR is modified by a Note. To minimize testing of the DGs, the Note allows a single test (instead of two tests, one for each unit)' to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by performing the test on either unit. If the DG fails one of these Surveillances, the DG should be considered inoperable on both units, unless the cause of the failure can be directly related to only one unit.

SR 3.8.1.13 Under accident conditions loads are sequentially connected to the bus by the automatic load sequence time delay relays.

The sequencing logic controls the permissive and starting signals to motor breakers to prevent overloading of the DGs due to high motor starting currents. The 10% load sequence time interval tolerance ensures that sufficient time exists for the DG to restore frequency and voltage prior to applying the next load and that safety analysis assumptions regarding ESF equipment time delays are not violated.

Reference 4 provides a summary of the automatic loading of ESF buses.

(continued) 1 Brunswick Unit 1 8 3.8-30 Revision No. 6 l 1

AC Sources-Operating B 3.8.1 l-BASES SURVEILLANCE- SR 3.8.1.13 (continued) l REQUIREMENTS The Frequency of 24 months is consistent with the recommendations of Regulatory Guide 1.9 (Ref.11), Table 1; t l

takes into consideration plant conditions required to perform the Surveillance; and is intended to be consistent

-with expected fuel cycle lengths.

This SR is modified by a Note. The reason for the Note is f i that performing the Surveillance' would remove a required i offsite circuit from service, perturb the electrical l distribution system, and challenge safety systems. Due to l the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, all four DGs, and associated load sequence relays, are required to be OPERABLE to supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to l reduce potential consequences associated with removing a l required offsite circuit from service during the performance of this Surveillance, reduce consequences of a potential perturbation to the electrical distribution systems during

- the performance of this Surveillance, and reduce challenges to safety systems, while at the same time avoiding the need to shutdown both units to perform this Surveillance, the Note only precludes satisfying this Surveillance Requirement for the load sequence relays associated with DG 1 and DG 2 when Urit 1 is in MODE 1, 2, or 3. During the performance i

of this Surveillance with Unit I not in MODE 1, 2, or 3 and i with Unit 2 in MODE 1, 2, or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications must ,be entered if a required offsite circuit, DG 1, or DG 2 is rendered inoperable by the performance of this Surveillance.

Credit may be taken for unplanned events that satisfy this '

SR.

SR 3.8.1.14 l

In the event of a DBA coincident with a loss of offsite .

! power, the DGs are-required to supply the necessary power to ESF systems so that the fuel, RCS, and containment design limits are not exceeded.

This Surveillance demonstrates DG operation during a loss of offsite power actuation test signal in conjunction with an l' ECCS initiation signal. This test verifies all actions encountered from the event', including shedding of the (continued)

I j Brunswick Unit 1 B 3.8-31 Revision No. 6 i y

7 AC Sources-0perating B 3.8.1 '

' BASES

, SURVEILLANCE' SR 3.8.1.14 (continued) 1: REQUIREMENTS nonessential loads and energization of the emergency buses and respective loads from the DG. It further demonstrates the capability of the DG to automatically achieve the required voltage and frequency within the specified time.

The 10.5 second time period, which is allowed for the DG to auto-start and connect-to its respective emergency bus, is conservatively derived from requirements of the accident analysis for responding to a design basis large break LOCA.

The Surveillance should be continued for a minimum of 5 minutes in order to demonstrate that all starting _

transients have decayed and stability has been achieved.

l The requirement to verify the connection and power supply of permanent and auto-connected loads is intended to

satisfactorily show the relationship of these loads to the

! DG loading logic. In certain circumstances, many of these l

loads cannot actually be connected or loaded without undue hardship or potential for undesired operation. For instance, Emergency Core Cooling Systems (ECCS) injection valves are not desired to be' stroked open, or systems are l not capable of being operated at full flow, or RHR systems performing a decay heat removal function are not desired to be realigned to the ECCS mode of operation.

In lieu of actual demonstration of connection and loading of loads, testing that adequately shows the capability of the DG system to perform these functions is acceptable. This testing may include any series of sequential, overlapping, or total steps so that the entire connection and loading

~

sequence is verified.

The Frequency of 24 months takes into consideration plant conditions required to perform the Surveillance and is intended to be consistent with an expected fuel cycle length.

This SR is modified by two Notes. The reason for Note 1 is to minimize wear and tear on the DGs during testing. For the purpose of this testing, the DGs must be started from l standby conditions, that is, with the engine coolant and oil being continuously circulated and temperature maintained consistent with procedural guidance. The reason for Note 2 is that performing the Surveillance would remove a required offsite circuit from service, perturb the electrical (continued)

Brunswick Unit 1 B 3,8-32 Revision No. 6 I l

i

l AC Sources-Operating B 3.8.1 BASES SURVEILLANC'E SR 3.8.1.14 (continued)

REQUIREMENTS distribution system, and challenge safety systems. Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, all four DGs are required to be OPERABLE to supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the potential consequences ,

associated with removing a required offsite circuit from service during the performance of this Surveillance, reduce consequences of a potential perturbation to the electrical i distribution systems during the performance of this Surveillance, and reduce challenges to safety systems, while at the same time avoiding the need to shutdown both units to perform this Surveillance, Note 2 only precludes satisfying this Surveillance Requirement for DG 1 and DG 2 when Unit 1 is in MODE 1, 2, or 3. During the performance of this Surveillance with Unit I not in MODE 1, 2, or 3 and with Unit 2 in MODE 1, 2, or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications must be entered if a required offsite circuit, DG 1, DG 2, or other supported Technical Specification equipment is rendered inoperable by the performance of this Surveillance. Credit l may be taken for unplanned events that satisfy this SR.

REFERENCES 1. UFSAR, Section 8.3.1.2.

2. UFSAR, Sections 8.2 and 8.3.

I

3. NRC Diagnostic Evaluation Team Report for Brunswick l Steam Electric Plant dated August 2, 1989, from i i

J.M. Taylor (NRC) to S.H. Smith, Jr. (CP&L).

l 4. UFSAR, Table 8.3.1 6. j

5. Safety Guide 9

6. UFSAR, Chapter 6.

7. UFSAR, Chapter 15.

l

8. 10 CFR 50.36(c)(2)(ii).

9. Regulatory Guide 1.93, December 1974.

10. Generic Letter 84-15.

(continued)

Brunswick Unit 1 B 3.8-33 Revision No. 6 1 t

r 1 I i AC Sources-0perating B 3.8.1 l : BASES REFERENCES 11. Regulatory Guide 1.9, July 1993, Revision 3.

l (continued) l 12. Regulatory Guide 1.137, January 1978.

13. IEEE Standard 308.

l l

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l Brunswick Unit 1 B 3.8-34 Revision No. 6 I

F AC Sources-Shutdown L

B 3.8.2 l

B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.2 AC Sources-Shutdown i

BASES BACKGROUND A description of the AC sources is provided in the Bases for LC0 3.8.1, "AC Sources-0perating."

APPLICABLE The OPERABILITY of the minimum AC sources during MODES 4 SAFETY ANALYSES and 5, and during movement of irradiated fuel assemblies in the secondary containment ensures that:

a. The facility can be maintained in the shutdown or refueling condition for extended periods;

b. Sufficient instrumentation and control capability is available for monitoring and maintaining the unit status; and

c. Adequate AC electrical power is provided to mitigate events postulated during shutdown, such as an inadvertent draindown of the vessel or a fuel handling accident.

In general, when the unit is shutdown the Technical Specifications requirements ensure that the unit has the capability to mitigate the consequences of postulated accidents. However, assuming a single failure and ,

concurrent loss of all offsite power is not required. The )

rationale for this is based on the fact that many Design Basis Accidents (DBAs) that are analyzed in MODES 1, 2, I and 3 have no specific analyses in MODES 4 and 5. Worst !

case bounding events are deemed not credible in MODES 4 and 5 because the energy contained within the reactor pressure boundary, reactor coolant temperature and pressure, and corresponding stresses result in the probabilities of occurrences significantly reduced or eliminated, and minimal consequences. These deviations from DBA analysis 4 assumptions and design requirements during shutdown conditions are allowed by the LC0 for required systems.

During MODES l', 2, and 3, various deviations from the analysis assumptions and design requirements are allowed within the ACTIONS. This allowance is in recognition that certain testing and maintenance activities must be (continued)

Brunswick Unit 1 8 3.8-35 Revision No. 6 l

AC Sources-Shutdown B 3.8.2 L

BASES

. APPLICABLE- conducted, provided an acceptable level of risk is not SAFETY ANALYSES exceeded. During MODES 4 and 5,. performance of a 1

-(continued) significant number of required testing and maintenance activities is also required. In MODES 4 and 5, the activities are generally planned and administratively controlled. Relaxations from typical MODES 1, 2, and 3 LC0 requirements are acceptable during shutdown MODES, based on:

a. The fact that time in an outage is limited. This is a risk prudent goal as well as a utility economic l

consideration.

l b. Requiring appropriate compensatory measures for l certain conditions. These may include administrative controls, reliance on systems that do not necessarily meet typical design requirements applied to systems credited in operation MODE analyses, or both-

c. Prudent utility consideration of the risk associated with multiple activities that could affect multiple systems.

d. Maintaining, to the extent practical, the ability to perform required functions (even if not meeting MODES 1, 2, and 3 OPERABILITY requirements) with systems assumed to function during an event.

In the event of an accident during shutdown, this LC0 )

ensures the capability of supporting systems necessary for !

avoiding immediate difficulty, assuming a loss of all !

offsite power.

~

The AC sources satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii)

(Ref. 1).

LC0 One Unit 1 offsite circuit capable of supplying the onsite Class IE power distribution subsystem (s) of LC0 3.8.8.

" Distribution Systems-Shutdown," ensures that all required Unit 1 loads are powered from offsite power. Two OPERABLE

.DGs, associated with distribution subsystem (s) required OPERABLE by LC0 3.8.8, ensures that a diverse power source is available for providing electrical power support assuming a loss of the offsite circuit (s). In addition, some Unit 2 ;

equipment may be required by Unit 1 (e.g., Control Room

' Emergency Ventilation (CREV) System components). Therefore, one Unit 2 qualified circuit between the offsite (continued)

Brunswick Unit 1 B 3.8-36 Revision No. 6 l l

AC Sources-Shutdown B 3.8.2 BASES LC0 transmission network and the onsite Class IE AC electrical (continued) power distribution subsystem (s), needed to support the Unit 2 equipment required to be OPERABLE, must also be OPERABLE. Together, OPERABILITY of the required offsite circuit (s) and DGs ensures the availability of sufficient AC sources to operate the plant in a safe manner and to mitigate the consequences of postulated events during shutdown (e.g., fuel handling accidents and reactor vessel draindown).

The qualified offsite circuit (s) must be capable of l maintaining rated frequency and voltage while connected to the respective emergency bus (es), and of accepting required loads during an accident. Qualified offsite circuits are those that are described in the UFSAR and are part of the licensing basis for the unit. The Unit 1 qualified offsite circuit consists of the incoming breaker and disconnect to and including the associated startup auxiliary transformer (SAT) or unit auxiliary transformer (UAT), the respective circuit path to and including the balance of plant bus (es), I and the circuit path to associated 4.16 kV emergency. bus (es) '

required by LC0 3.8.8. The Unit 2 qualified offsite circuit consists of the incoming breaker and disconnect to and l including the associated SAT or UAT, the respective circuit path to and including the balance of plant bus (es), and the circuit path to associated 4.16 kV emergency bus (es) required by LCO 3.7.3, LC0 3.7.4 and LC0 3.8.5.

The required DGs must be capable of starting,-accelerating to minimum accepta' ole frequency and voltage, and connecting to its respective 4.16 kV emergency bus on detection of bus undervoltage. This sequence must be accomplished within j 10.5 seconds. Each required DG is required to have an OPERA.BLE air start system consisting of one air header, one ;

receiver, associated air compressor, piping, valves, and l instrument controls to ensure adequate starting and control l air capacity. Additionally, each DG must be capable of accepting required loads within the assumed loading sequence )

intervals, and must continue to operate until offsite power can be restored to the 4.16 kV emergency buses. These capabilities are required to be met from a variety of initial conditions such as DG in standby with engine at ambient conditions. Additional DG capabilities must be demonstrated to meet required Surveillances, e.g.,

capability of the DG to revert to standby status on an ECCS l

signal while operating in parallel test mode. Proper (continued) I Brunswick Unit 1 B 3.8-37 Revision No. 6 l j l

AC Sources-Shutdown B 3.8.2 BASES LCO sequencing of loads, including tripping of nonessential (continued) loads, is required function for DG OPERABILITY. The necessary portions of +he Nuclear Service Water System are also required to provide appropriate cooling to each required DG.

It is acceptable for 4.16 kV emergency buses to be cross tied during shutdown conditions, permitting a single offsite power circuit to supply all required buses provided both units are shutdown.

APPLICABILITY The AC sources are required to be OPERABLE in MODES 4 and 5 and during movement of irradiated fuel assemblies in the secondary containment to provide assurance that:

a. Systems providing adequate coolant inventory makeup are available for the irradiated fuel assemblies in the core in case of an inadvertent draindown of the reactor vessel;

b. Systems needed to mitigate a fuel handling accident are available;

c. Systems necessary to mitigate the effects of events that can lead to core damage during shutdown are available; and i

d. Instrument.ation and control capability is available for monitoring and maintaining the unit in a cold i shutdown condition or refueling condition. >

AC power requirements for MODES 1, 2, and 3 are covered in LCO 3.8.1.

ACTIONS LC0 3.0.3 is not applicable while in MODE 4 or 5. However, since irradiated fuel assembly movement can occur in Mode 1, 2, or 3, the ACTIONS have been modified by a Note stating that LC0 3.0.3 is not applicable. If moving irradiated fuel assemblies while in MODE 4 or 5, LC0 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, or 3, the fuel movement is independent of reactor !

operations. Entering LC0 3.0.3, while in MODE 1, 2, or 3, would require the unit to be shutdown, but would not require immediate suspension of movement of irradiated fuel 1 assemblies. The Note to the ACTIONS "LCO 3.0.3 is not (continued)

Brunswick Unit 1 B 3.8-38 Revision No. 6 l l

~

l I AC Sources-Shutdown B 3.8.2 l

BASES l

i ACTIONS' applicable," ensures that the actions for immediate I (continued)~ suspension of irradiated fuel assembly movement are not postponed due to entry into LC0 3.0.3.

A.1 and B.1 With one or more required offsite circuits inoperable, or with one DG inoperable, the remaining required AC sources may be capable of supporting sufficient required features (e.g., system, subsystem, division, component, or device) to allow continuation of CORE ALTERATIONS, fuel movement, and operations with a potential for draining the reactor vessel.

For example, if two 4.16 kV emergency buses are required per LCO 3.8.8, one emergency bus with offsite power available may be capable of supplying sufficient required features.

By the allowance of the option to declare required. features inoperable that are not powered from offsite power (Required Action A.1) or capable of being powered by the required DG (Required Action B.1), appropriate restrictions'can be implemented in accordance with the affected required feature (s) LCOs' ACTIONS. Required features remaining powered from the qualified offsite. power circuit, even if the circuit is inoperable to other required features, are not. declared inoperable by this Required Action.

A.2.1. A.2.2. A.2.3. A.2.4, B.2.1. B.2.2 B.2.3 B.2.4 C.l.

C.2. C.3, and C.4 With an offsite circuit not available to all required 4.16 kV emergency buses or one required DG inoperable, the option still exists to declare all required features inoperable (per Required Actions A.1 and B.1). Since this option may involve undesired administrative efforts, the-allowance for sufficiently conservative actions is made.

With two required DGs inoperable, the minimum required diversity of AC power sources is not available. It is,

{

i therefore, required to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies in the secondary containment, and

(' '

activities that could result in inadvertent draining of the reactor vessel.

Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition.

'These' actions minimize the probability of the occurrence of postulated events. It is further required to immediately (continued)

Brunswick Unit 1 B 3.8-39 Revision No. 6 1

i AC Sources-Shutdown B 3.8.2 I

BASES ACTIONS A.2.1. A.2.2. A.2.3 A.2.4. B.2.1 B.2.2 B.2.3. B.2.4, C.l.

C.2. C.3, and C.4 (continued) initiate action to restore the required AC sources and to continue this action until restoration is accomplished in order to provide the necessary AC power to the plant safety q systems. '

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. The restoration of the required AC electrical power sources should be completed as quickly as possible in order to minimize the time during which the plant safety systems may -

be without sufficient power.

Pursuant to LC0 3.0.6, the Distribution System ACTIONS would not be entered even 'if all AC sources to it are inoperable, resulting in de-energization. Therefore, the Required Actions of Condition A have been modified by a Note to indicate that when Condition A is entered with no AC power to any required 4.16 kV emergency bus, ACTIONS for LC0 3.8.8 must be immediately entered. This Note allows Condition A to provide requirements for the loss of the offsite circuit whether or not a required bus is de-energized. LC0 3.8.8 provides the appropriate restrictions for the situation involving a de-energized bus.

l SURVEILLANCE SR 3.8.2.1 REQUIREMENTS l SR 3.8.2.1 requires the SRs from LCO 3.8.1 that are necessary for ensuring the OPERABILITY of the required AC sources in other than MODES 1, 2, and 3 to be met. SR 3.8.1.8 is not required to be met since only one offsite circuit is required to be OPERABLE. SR 3.8.1.12 is not l required to be met because the required OPERABLE DG(s) is not required to undergo periods of being synchronized to the offsite circuit. Refer to the corresponding Bases for LC0 3.8.1 for a discussion of each SR.

This SR is modified by a Note. The reason for the Note is

, to preclude requiring the OPERABLE DG(s) from being paralleled with the offsite power network or otherwise rendered inoperable during the performance of SRs, and to preclude de-energizing a required 4.16 kV emergency bus or (continuedl Brunswick Unit 1 B 3.8-40 Revision No. 6 I 1

3

7 4,

AC Sources-Shutdown B 3.8.2 BASES SURVEILLANCE SR 3.8.2.1 (continued)

REQUIREMENTS disconnecting a required offsite circuit during performance of SRs. With limited AC sources available, a single event !

could compromise both the required circuit (s) and the DGs.

It is the intent that these SRs'must still be capable of I being met, but actual performance is not required during I periods when the DGs and offsite circuit (s) are required to be OPERABLE unless Unit 2 Specification 3.8.1, "AC Sources-Operating," requires performance of these SRs.

When Unit 2 Specification 3.8.1 requires performance of these SRs,'AC sources availability is not limited due to the Unit 2 requirements for AC source OPERABILITY. Therefore, a single event, in this condition, is not expected to compromise both_the required offsite circuit (s) and the DG(s).

REFERENCES 1. 10 CFR 50.36(c)(2)(ii).

1 l

I l

V l L

l l-Brunswick Unit 1 B 3.8-41 Revision No. 6 l

I 1

Diesel Fuel Oil l B 3.8.3 B 3.8 ELECTRICAL POWER SYSTEMS I

B 3.8.3 Diesel Fuel Oil BASES i

BACKGROUND Each diesel generator (DG) is provided with storage tanks having a fuel oil capacity sufficient to operate that DG for a period of approximately 7 days while the DG is operating i' at rated load as discussed in UFSAR, Section 8.3.1.1.6.2.8 (Ref. 1). The fuel consumption rate is calculated using the assumption that four DGs are available. The diesel generator fuel . oil capacity in the combination of the fuel oil volumes of the Seismic Class I day fuel oil storage tanks (one tank for each diesel generator) and the Seismic Class I engine mounted fuel tanks (one tank attached to each diesel generator) provide approximately four days of diesel generator operation at rated load. The main fuel oil storage tank provides approximately three additional days of diesel generator operation at rated load to each of the day fuel oil storage tanks. The main fuel oil storage tank is 3 seismically designed but not seismically qualified. l Following the postulated loss of the main fuel oil storage tank, the onsite fuel oil capacity in seismically qualified ,

storage tanks is sufficient to operate the DGs for longer than the time to replenish the onsite supply from outside sources as discussed in Reference 1.

Fuel oil is transferred from the day fuel oil storage tank to the engine mounted fuel tank by either of two transfer pumps associated with each day fuel oil storage tank. Fuel oil is gravity fed from the main fuel oil storage tank to the day fuel oil storage tanks through manual or automatic i valves. However, level in the day fuel oil storage tanks is j currently maintained through the use of the manual valves. i Redundancy of pumps and piping, and the normally isolated '

gravity feed lines from the main fuel oil storage tank to the day fuel oil storage tanks, precludes the failure of one '

pump, or the rupture of any pipe, valve, or tank to result in the loss of more than one DG. All outside tanks, pumps, and piping (other than the main fuel oil storage tank and a ,

portion of the associated piping) are located underground.

(continued) 4 I

Brunswick Unit 1 B 3.8-42 Revision No. 6 i

7 Diesel Fuel Oil l B 3.8.3 l

l l BASES BACKGROUND For proper operation of the standby DGs, it is necessary to (continued) ensure the proper quality of the fuel oil. Regul atory Guide 1.137 (Ref. 2) addresses the recommended fuel oil practices as modified by Reference 3. The fuel oil properties governed by SRs of this Specification are the l water content, the kinematic viscosity, and impurity level.

l APPLICABLE The initial conditions of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in UFSAR, Chapter 6 (Ref. 4), and Chapter 15 (Ref. 5), assume Engineered Safety Feature (ESF) systems are OPERABLE. The DGs are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems so that reactor fuel, Reactor Coolant System, and containment design limits are not exceeded. These limits are discussed in more detail in the Bases for Section 3.2, l

" Power Distribution Limits"; Section 3.5, " Emergency Core l Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC) System"; and Section 3.6, " Containment Systems."

Since diesel fuel oil supports the operation of the standby AC power sources, it satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii) (Ref. 6).

LCO Stored diesel fuel oil is required to have sufficient supply for approximately 7 days of operation at rated load. It is also required to meet specific standards for quality. These requirements, in conjunction with an ability to obtain replacement supplies within approximately 7 days, support the availability of DGs required to shut down the reactor and to maintain it in a safe condition for an anticipated j operational occurrence (A00) or a postulated DBA with loss of offsite power. DG engine mounted tank fuel oil requirements, as well as transfer capability from the day fuel oil storage tank to the engine mounted tank, are l addressed in LC0 3.8.1, "AC Sources-Operating," and l

LC0 3.8.2, "AC Sources-Shutdown."

(continued) l i

Brunswick Unit 1 B 3.8-43 Revision No. 6 !

]

)

Diesel fuel Oil l B 3.8.3 BASES (continued)

APPLICABILITY The AC sources (LC0 3.8.1 and LC0 3.8.2) are required to l

I ensure the availability of the required power to shut down the reactor and maintain it in a safe shutdown condition after an A00 or a postulated DBA. Because stored diesel l fuel oil supports LC0 3.8.1 and LC0 3.8.2, stored diesel :

I fuel oil, is required to be within limits when the l associated DG is required to be opt.RABLE.

i ACTIONS The ACTIONS Table is modified by a Note indicating that separate Condition entry is allowed for each DG. This is l acceptable, since the Required Actions for each Condition l provide appropriate compensatory actions for each inoperable DG subsystem. Complying with the Required Actions for one inoperable DG subsystem may allow for continued operation, and subsequent inoperable DG subsystem (s) governed by separate Condition entry and application of associated l Required Actions.

A.1 and B.1 With one or more required DGs with fuel oil level in the associated day fuel oil storage tanks < 22,650 gallons per required DG and 2 17,000 gallons per required DG and the fuel oil level in the main fuel oil storage tank 2 20,850 gallons per required DG, the approximate 7 day fuel !

oil supply for a required DG is not available. however, Condition A is restricted to fuel oil level reductions that maintain at least an approximate 6 day supply (at least an approximate 3 day supply-is available in the required day fuel oil storage tanks and an approximate 3 day supply is available in the main fuel oil storage tank).

With one or more required DGs with fuel oil level in the main fuel oil storage tank < 20,850 gallons per required DG and 2 13,900 gallons per required DG and the fuel oil level in the required day fuel oil storage tank (s) 2 22,650 gallons per required DG, the approximate 7 day fuel oil supply for a required DG is not available. However, Condition B is restricted to fuel oil level reductions that maintain at least an approximate 6 day supply (at least an approximate 2 day supply is available in the main fuel oil storage tank and an approximate 4 day supply is available in the required day fuel oil storage tanks (s)).

(tontinued)

Brunswick Unit 1 B 3.8-44 Revision No. 6 I

Diesel Fuel Oil B 3.8.3 BASES 1

l ACTIONS A.1 and B.1 (continued)

These circumstances may be caused by events such as:

a. Full load operation required for an inadvertent start while at minimum required level; or

b. Feed and bleed operations that may be necessitated by increasing particulate levels or any number of other oil quality degradations.

These restrictions (Required Actions A.1 and B.1) allow sufficient time for obtaining the requisite replacement volume and performing the analyses required prior to addition of the fuel oil to the tank. A period of 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months is considered sufficient to complete restoration of the required level prior to declaring the DG inoperable. This period is acceptable based on the remaining capacity l

(2: approximately 6 days), the fact that procedures will be initiated to obtain replenishment, and the low probability of an event during this brief period.

C.1 This Condition is entered as a result of a failure to meet the acceptance criterion for particulates. Normally, trending of particulate levels allows sufficient time to correct high particulate levels prior to reaching the limit of acceptability. Poor sample procedures (bottom sampling),

contaminated sampling equipment, and errors in laboratory analysis can produce failures that do not follow a trend.

Since the presence of particulates does not mean failure of the fuel oil to burn properly in the diesel engine, since particulate concentration is unlikely to change significantly between Surveillance Frequency intervals, and since proper engine performance has been recently demonstrated (within 31 days), it is prudent to allow a l brief period prior to declaring the associated DG ,

inoperable. The 7 day Completion Time allows for further ,

evaluation, resampling, and re-analysis of the DG fuel oil. !

(continued)

Brunswick Unit 1 B 3.8-45 Revision No. 6 l

Diesel Fuel Oil 8 3.8.3 4

BASES ACTIONS D.1 (continued)

With a Required Action and as mciated Completion Time of Condition A, B, or C not met, or the stored diesel fuel oil not within limits for reasons other than addressed by Conditions A, B, or C, the associated DG may be incapable of performing its intended function and must be immediately declared inoperable.

' SURVEILLANCE SR 3.8.3.1 REQUIREMENTS This SR provides verification that-there is an adequate inventory of fuel oil in the storage tanks to support each DG's operation for approximately 7 days at rated load. The approximate 7 day period is sufficient time to place the unit in a safe shutdown condition and to bring in replenishment fuel from an offsite location. For the purposes of this SR, the verification of the main fuel oil storage tank fuel oil volume is performed on a per DG basis.

This per DG volume is obtained using the following equation:

~

~ M vot-Uvot I vot N

_ oa _

L

where l

M yot- - measured fuel oil volume of the main fuel oil storage tank, l U yot - unusable fuel oil volume of the main I

fuel oil storage tank, and j N

oa

= number of.DGs required to be OPERABLE.

, The results: from this equation must be 2: 20,850 gallons in order to satisfy the acceptance criteria of SR 3.8.3.1.b.

The 31 day Frequency is adequate to ensure that a sufficient supply of fuel oil is available, since low level alarms are provided and unit operators would be aware of any large uses i of fuel oil during this period. i (continued)

I Brunswick Unit 1 B 3.8-46 Revision No. 6 I l

I

r; Diesel Fuel Oil B 3.8.3 BASES SURVEILLANCE SR 3.8.3.2 REQUIREMENTS Once per 92 days, the stored fuel oil is sampled in accordance with ASTM D4057-88, (Ref. 7) and analyzed to establish that the viscosity limits specified in Table 1. of ASTM D975-88 (Ref. 7) are met for stored fuel 011. The 92 day period is acceptable because fuel oil visc6:ity, even if it was not within stated limits, would not have an immediate effect on DG operation. This Surveillance, in combination with the fuel oil delivery certificate of compliance, ensures the availability of high quality fuel oil for the DGs.

Fuel oil degradation during long term storage shows up as an increase in particulate, mostly due to oxidation. The 1 presence of particulate does not mean that the fuel oil will not burn properly in a diesel engine. The particulate can cause fouling of filters and fuel oil injection equipment, however, which can cause engine failure.

Particulate concentrations should be determined in accordance with ASTM D2276-89 (Ref. 7), Method A3. This i method involves a gravimetric determination of total particulate concentration in the fuel oil and has a limit of 10 mg/1. It is acceptable to obtain a field sample for subsequent laboratory testing in lieu of field testing. For the BNP design, the total volume of stored fuel oil is contained in more than two interconnected tanks. 'Therefore, each tank must be considered and tested separately.

The Frequency of this test takes into consideration fuel oil degradation trends that indicate that particulate concentration is unlikely to change significantly between Frequency intervals.

The acceptability of new diesel fuel oil is verified by the use of a certificate of compliance provided by the diesel fuel oil supplier for each new fuel oil delivery. The certificate of compliance includes certification of each of the ASTM 2-D fuel oil properties included in Table 1 of ASTM l D975-88 (Ref. 7) and API gravity are within required limits.

Therefore, the acceptability of new fuel oil for use prior l to addition to the storage tanks is determined by verifying i that the new fuel oil has not become contaminated with other i products during transit, thus altering the quality of the j (continued) i Brunswick Unit 1 B 3.8-47 Revision No. 6 l

Diesel fuel Oil B 3.8.3'

. BASES SURVEILLANCE- SR 3.8.3.2 (continued)

REQUIREMENTS fuel oil. This ensures new fuel oil quality is maintained consistent with that identified in the certificate of compliance. Once the verification is satisfactorily completed, the fuel oil may be added to the storage tanks without concern for contaminating the entire volume of fuel oil in the storage tanks.

Failure to determine the acceptability of the new diesel fuel oil is cause for rejecting the new fuel oil, but does not represent a failure to meet the LC0'since the fuel oil is not added to the storage tanks.

SR 3.8.3.3 Microbiological fouling is a major cause of fuel oil degradation. There are numerous bacteria that can grow in fuel oil and cause fouling, but all must have a water environment in order to survive. Removal of water from the fuel storage tanks once every 31 days eliminates the necessary environment for bacterial survival. This is the most effective means of controlling microbiological fouling.

In addition, it eliminates the potential for water entrainment in the fuel oil during DG operation. Water may come from any of several sources, including condensation, ground water, rain water, contaminated fuel oil, and from breakdown of the fuel oil by bacteria. Frequent checking for and removal of accumulated water minimizes fouling and provides data regarding the watertight integrity of the fuel oil system. The Surveillance Frequency is established by Regulatory Guide 1.137 (Ref. 2). This SR is for preventive maintenance. The presence of water does not necessarily i represent failure of this SR, provided the accumulated water is removed during performance of the Surveillance.

REFERENCES 1. UFSAR, Section 8.3.1.1.6.2.8.

2. Regulatory Guide 1.137, January 1978.

l 3. UFSAR, Section 1.8.

4. UFSAR, Chapter 6.

l (continued _1

-Brunswick Unit 1 B 3.8-48 Revision No. 6 1

Diesel Fuel Oil B 3.8.3 BASES REFERENCES 5. UFSAR, Chapter 15. i

'(continued) 6.

10 CFR 50.36(c)(2)(ii).

7. ASTM Standards: D4057-88; 0975-88; and D2276-89. l

)

I Bruitswick Unit 1 B 3.8-49 Revision No. 6 1

DC Sources-0perating B 3.8.4 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.4 DC Sources-Operating BASES

' BACKGROUND The DC electrical power system provides the AC emergency power system with control power. It also provides both motive and control power to selected-safety related equipment. Also, these DC subsystems provide a source of uninterruptible power to AC vital buses. As required by design bases in UFSAR Section 8.3.2.1.1 (Ref. 1), the DC electrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a single failure. The DC electrical power system also conforms to the recommendations of Safety Guide 6 (Ref. 2).

The DC power sources provide both motive and control power to selected safety related equipment, as well as power for circuit breaker control, relay operation, plant annunciation, and emergency lighting. There are two independent divisions per unit, designated Division I and Division II. Each division consists of a 250 VDC battery center tapped to form two 125 VDC batteries. Each 125 VDC battery has an' associated full capacity battery charger.

The chargers are supplied from the same AC load groups for which the associated DC subsystem supplies the control power.

During ' normal- operation, the DC loads are powered from the battery chargers with the batteries floating on the system.

In case of loss of normal power to the battery charger, the DC loads are automatically powered from the station batteries.

The DC power distribution system is described in more detail in Bases for LC0 3.8.7, " Distribution System-0perating,"

and LC0 3.8.8, " Distribution System-Shutdown."

Each battery has adequate storage capacity to carry the required load continuously for 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months .

(continued)

Brunswick Unit 1 B 3.8-50 Revision No. 6 1

DC Sources-0perating B 3.8.4 BASES l BACKGROUND Each DC battery subsystem (division)-is separately housed in l

(continued) a battery room with its associated chargers and main DC distribution switchboard. This arrangement provides complete separation and isolation of the redundant DC subsystems to ensure that a single failure in one subsystem does not cause a failure in a redundant subsystem.

l The batteries for DC electrical power subsystems are sized to produce required capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles i and the 100% design demand. The minimum design voltage l limit is 105/210 V.

Each battery charger of DC electrical power subsystem has ample power output capacity for the steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged.

Each station service battery charger has sufficient capacity to restore the battery from the design minimum charge to its fully charged state in approximately 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months while supplying normal steady state loads (Ref. 3).

A description of the Unit 2 DC power sources is provided in the Bases for Unit 2 LC0 3.8.4, "DC Sources-0perating".

APPLICABLE The initial conditions of Design Basis Accident (DBA) and l SAFFTY ANALYSES transient analyses in the UFSAR, Chapter 6 (Ref. 4) and Chapter 15 (Ref. 5), assume that Engineered Safety Feature (ESF) systems are OPERABLE. The DC electrical power system provides normal and emergency DC electrical power for the diesel generators -(DGs), 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 i upon meeting the design basis of the unit. This includes l maintaining DC sources OPERABLE during accident conditions in the event of:

a. An assumed loss of all offsite AC power; and

b. A worst case single failure.

The DC sources satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii)

(Ref 6).

(continued)

Brunswick Unit 1 B 3.8-51 Revision No. 6 l l

l

n-DC Sources-0perating B 3.8.4 l

BASES (continued)

L LC0 The Unit 1 Division I and Division 11 DC electrical power subsystems, with each DC subsystem consisting of two 125 V batteries (Batteries lA-1 and 1A-2 for Division I and Batteries 18-1 and 18-2 for Division II), two battery chargers (one per battery) and the corresponding control L equipment and interconnecting cabling supplying power to the associated bus are required to be OPERABLE to ensure the availability of the required power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (A00) or a postulated DBA. In addition, DC control power for operation of two of the four 4.16 kV emergency buses and two of the four 480 V emergency buses, as well as control power for two of the four DGs, is provided by the Unit 2 DC electrical power subsystems. ;

l Therefore, Unit 2 Division I and Division II DC electrical power subsystems are also required to be OPERABLE. Unit 2 DC electrical power subsystem OPERABILITY requirements are j the same as those required for a Unit 1 DC electrical power subsystem. Loss of any DC electrical power subsystem does not prevent the minimum safety function from being performed (Ref. 1).

APPLICABILITY The DC electrical power sources are required to be OPERABLE in MODES 1, 2, and 3 to ensure safe unit operation and to ensure that:

i

a. Acceptable fuel design limits and reactor coolant ;

pressure boundary limits are not exceeded as a result l of A00s or abnormal transients; and

b. Adequate core cooling is provided, and containment )

integrity and other vital functions are maintained in i the event of a postulated DBA. ]

The DC electrical power requirements for MODES 4 and 5 and other conditions in which the DC electrical power sources are required are addressed in LC0 3.8.5, "DC Sources-Shutdown."

ACTIONS A.1 Pursuant to LC0 3.0.6, the Distribution Systems-0perating ACTIONS would not be entered even if the DC electrical power subsystem inoperability resulted in de-energization of an AC electrical power distribution subsystem or a DC electrical (continued)

Brunswick Unit 1 B 3.8-52 Revision No. 6 l l l

1

DC Sources-Operating B 3.8.4 BASES ACTIONS A.1 (continued).

power distribution subsystem. Therefore, the Required Actions of Condition A are modified by a Note to indicate that when Condition A results in de-energization of an AC electrical power distribution subsystem or a DC electrical power distribution subsystem, Actions of LC0 3.8.7 must be immediately entered. This allows Condition A to provide requirements for the. loss of a DC electrical power subsystem without regard to wiiether a distribution subsystem is de-energized. LC0 3.8.7 provides the appropriate restriction for a de-energized distribution subsystem.

Condition A represents one division with a loss of ability to completely respond to an event, and a potential loss of ability to remain energized during normal operation. It is therefore imperative that the operator's attention focus on

. stabilizing the unit, minimizing the potential for complete loss of DC power to the affected division.

If one of the required DC electrical power subsystems is inoperable (e.g., inoperable battery, inoperable battery charger (s), or inoperable battery charger and associated

-inoperable battery), the remaining DC' electrical power subsystems have the capacity to support a safe shutdown and to mitigate an accident condition. Since a subsequent worst

-case single failure could, however, result in the loss of minimum necessary DC electrical subsystems to mitigate a worst case accident. continued power operation should not exceed 7 days. The Completion time is based on the capacity and capability of the remaining DC Sources, including the enhanced reliability afforded by the capability to manually transfer DC loads to the opposite unit's DC electrical power distribution subsystems.

B.1 and B.2 If the DC electrical power subsystem cannot be restored to OPERABLE status within the required Completion Time or if two or more DC electrical power subsystems are inoperable, the unit must be brought to a MODE in which the LC0 does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within

'36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, (continued)

Brunswick Unit.1 8 3.8-53 Revision No. 6 l

DC Sources-Operating B 3.8.4 l

BASES ACTIONS B.1 and B.2 (continued) l based on operating experience, to reach the required plant l conditions from full power conditions in an orderly manner and without challenging plant systems. The Completion Time to bring the unit to MODE 4 is consistent with the time required in Regulatory Guide 1.93 (Ref. 7).

SURVEILLANCE- SR 3.8.4.1 REQUIREMENTS l Verifying battery terminal voltage while on float charge for i

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 i required to overcome the internal losses 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. The 7 day Frequency is conservative when compared with manufacturer recommendations and IEEE-450 (Ref. 8).

SR 3.8.4.2 Visual inspection to detect corrosion of the battery cells and connections, or measurement of the resistance of each ,

inter-cell and inter-rack connection, provides an indication

of physical damage or abnormal deterioration that could potentially degrade battery performance.

The connection resistance limits are s 1.2 times the established benchmark resistance values for the connections or s 5 ohms above the established benchmark resistance values for the connections, whichever is higher. These connection resistance acceptance criteria were derived from IEEE-450 (Ref. 8) and IEEE-484 (Ref. 9), respectively. ;

l The Frequency for these inspections, which can detect !

conditions that can cause power losses due to resistance heating, is 92 days. This Frequency is consistent with manufacturers recommendations.

(continued)

Brunswick Unit 1 B 3.8-54 Revision No. 6 l

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.3 REQUIREMENTS (continued) 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).

The 18 month Frequency for the Surveillance is based on engineering judgement. 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 3.8.4.4 Visual inspection of inter-cell and inter-rack connections provides an indication of physical damage or abnormal deterioration that could indicate degraded battery condition. The anti-corrosion material 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 I is removed during performance of this Surveillance.

The 18 month Frequency for the Surveillance is based on engineering-judgement.. 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.

)

i cR 3.8.4.5 - J j

Battery charger capability requirements are derived from the I design capacity of the chargers. According to Reference 3, the battery charger supply is required to be based on the j (continued) I l

Brunswick Unit 1 B 3.8-55 Revision No. 6 I i

E l-DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.5- (continued)

REQUIREMENTS largest combined demands of the various steady state loads and the charging capacity to restore the battery from the

j. '

design minimum charge state to the fully charged state, I under any load condition. The minimum required amperes and duration ensures that these requirements can be' satisfied.

1 1 The Frequency is acceptable, given battery charger-reliability and the other administrative controls existing to ensure adequate charger performance during these 24 month intervals.- In addition, this Frequency is intended to be consistent-with expected fuel cycle lengths.

SR 3.8.4.6 A battery service test is a special test of the battery's capability, as found, to satisfy the design requirements (battery duty cycle) of the DC electrical power system. The discharge rate and test length corresponds to the design duty cycle requirements as s p fied in Reference 10.

l The Frequency of 24 months is acceptable, given unit conditions required to perform.the test and the other requirements existing to ensure adequate battery performance during these 24 month intervals. In addition, this i Frequency is intended to be consistent with expected fuel cycle lengths.

This SR is modified by three Notes. Note 1 allows the performance of a modified performance discharge test in lieu of a service test once per 60 months. This substitution is acceptable because a modified performance discharge test.

represents a more severe test of battery capacity than I SR 3.8.4.6. The reason for Note 2 is that performing the Surveillance would remove a required DC electrical power subsystem from service, perturb the electrical distribution system, and challenge safety systems. Due to the shared !

configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, both Unit I and Unit 2. DC electrical power subsystems are required to supply power to these-systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the potential j consequences associated with removing a required DC electrical power subsystem from service during the 1 (continued)

Brunswick Unit l' B 3.8-56 Revision No. 6 l l

DC Sources-0perating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.6 (continued)

REQUIREMENTS performance of this Surveillance, reduce consequences of a potential perturbation to the electrical distribution systems during the performance of this Surveillance, and reduce challenges to safety systems, while at the same time l l avoiding the need to shutdown both units to perform this l Surveillance, Note 2 only precludes satisfying this Surveillance for the Unit 1 DC electrical power subsystems when Unit 1 is in MODE 1 or 2. During the performance of this Surveillance with Unit I not in MODE 1 or 2 and with Unit 2 in MODE 1, 2, or 3; the applicable ACTIONS of the Unit I and Unit 2 Technical Specifications must be entered if a required DC electrical power subsystem or other supported Technical Specification equipment is rendered inoperable.by the performance of this Surveillance. Credit may be taken for unplanned events that satisfy the 1 Surveillance. To minimize testing, Note 3 allows a single l test (instead of two tests, one for each unit) to satisfy the requirements for both units. -This is allowed since the main purpose of the test can be met by performing the test ,

on a single unit. If a DC electrical power subsystem fails the Surveillance, the DC electrical power subsystem should be considered inoperable for both units.

SR 3.8.4.7 A battery performance discharge test is a test of constant current capacity of a battery, normally done in the as found condition, 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.

A battery 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 1 performance discharge test, both of which envelope the duty cycle of the service test. 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 l changed to that for the performance test without j compromising the results of the performance discharge test. l

_ _ , (continued) i l

Brunswick Unit 1 B 3.8-57 Revision No. 6 l l

F DC Sources-0perating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.7 (continued)

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

A modified discharge test is a test of the battery capacity and its ability to provide a high rate, short duration load '

i (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 i to those specified for a performance discharge test. Either the battery performance discharge test or the modified performance discharge test is acceptable for satisfying SR 3.8.4.7; however, only the modified performance discharge test may be used to satisfy SR 3.8.4.7 while satisfying the requirements of SR 3.8.4.6 at the same time.

The acceptance criteria for this Surveillance is consistent with IEEE-450 (Ref. 8) and IEEE-485 (Ref. 11). These references recommend that the battery be replaced if its capacity is below 80% of the manufacturer's rating. A capacity of 80% shows that the battery rate of deterioration 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 degradation, or if the battery has reached 85%

of its expected life and capacity is < 100% of the manufacturer's rating, the Surveillance Frequency is reduced to 12 months. However, if the battery shows no degradation but h'as reached 85% of its expected life, the Surveillance Frequency is only reduced to 24 months for batteries that retain capacity 2: 100% of the manufacturer's rating. !

Degradation is indicated, according to IEEE-450 (Ref.'8),

when the battery capacity drops by more than 10% relative to :

its capacity on the previous _ performance test or when it is l 10% below the manufacturer's rating. The 60 month Frequency !

is consistent with the recommendations in IEEE-450 (Ref. 8).

The 12 month and 24 month Frequencies are derived from the recommendations in IEEE-450 (Ref. 8).

(continued) i Brunswick Unit 1 B 3.8-58 Revision No. 6 I

DC Sources-0perating B 3.8.4 BASES l

SURVEILLANCE SR 3.8.4.7 (continued)

REQUIREMENTS This SR is modified by two Notes. The reason for Note 1 is that performing the Surveillance would remove a required DC electrical power subsystem from service, perturb the electrical distribution system, and challenge safety systems. Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, both Unit 1 and Unit 2 DC electrical power subsystems are required to supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the potential consequences associated with removing 'a required DC electrical power subsystem from service during the performance of this Surveillance, reduce consequences of a potential perturbation to the electrical distribution systems during the performance of this

, Surveillance, and reduce challenges to safety systems, while I

at the same time avoiding the need to shutdown both units to perform this Surveillance, Note 1 only precludes satisfying this Surveillance for the Unit 1 DC electrical power subsystems when Unit 1 is in MODE 1 or 2. During the performance of this Surveillance with Unit I not in MODE 1 or 2 and with Unit 2 in MODE 1, 2, or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications must be entered if a required DC electrical power. subsystem or other supported Technical Specification equipment is rendered inoperable by the performance of this Surveillance.

Credit may'be taken for unplanned events that satisfy the Surveillance. To minimize testing, Note 2 allows a single-test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the test can be met by performing the test on a single unit. If a DC electrical power subsystem fails the Surveillance, the DC electrical power subsystem should be considered inoperable for both units.

-REFERENCES- 1. UFSAR, Section 8.3.2.1.1.

2. Safety Guide 6.

3. UFSAR, Section 8.3.2.1.2.

4. UFSAR, Chapter 6.

5. UFSAR,-Chapter 15.

(continued)

Brunswick Unit 1 B 3.8-59 Revision No. 6 l

i DC Sources-0perating B 3.8.4 BASES i

i REFERENCES 6. 10 CFR 50.36(c)(2)(ii).

(continued)

7. Regulatory Guide 1.93, December 1974.

8. IEEE Standard 450, 1987. l

9. IEEE Standard 484, 1996,

10. UFSAR,-Section 8.3.2.

11. IEEE Standard 485, 1983.

l I

e

)

1 Brunswick Unit 1 B 3.8-60 Revision No. 6 1

DC Sources-Shutdown B 3.8.5 B 3.8 ELECTRICAL POWER SYSTEMS i B 3.8.5 DC Sources-Shutdown BASES BACKGROUND A description of the DC sources is provided in the Bases for LC0 3.8.4, "DC Sources-Operat ing." ;

1 APPLICABLE The initial conditions of Design Basis Accident and I SAFETY ANALYSES transient analyses in the UFSAR, Chapter 6 (Ref. 1) and Chapter 15 (Ref. 2), assume that Engineered Safety Feature systems are OPERABLE. The DC electrical power system provides normal and emergency DC electrical power for the diesel generators (DGs), emergency auxiliarias, and control and switching during all MODES of operation and during movement of irradiated fuel assemblies in the secondary containment.

The OPERABILITY of the DC subsystems is consistent with the j initial assumptions of the accident analyses and the i requirements for the supported systems' OPERABILITY.

The OPERABILITY of the minimum DC electrical power sources during M') DES 4 and 5 and during movement of irradiated fuel assemblies in the secondary containment ensures that:

a. The facility can be maintained in the shutdown or refueling condition for extended periods; :

b. Sufficient instrumentation and control capability is available for monitoring and maintaining the unit status; and

c. Adequate DC electrical power is provided to mitigate ,

events postulated during shutdown, such as an inadvertent draindown of the vessel or a fuel handling accident.

The DC sources satisfy Criterion 3 of 10 CFR. 50.36(c)(2)(ii)

(Ref. 3).

LC0 The Unit 1 DC electrical power subsystems each consisting of two 125 V batteries in series, two battery chargers (one per battery), and the corresponding control equipment and interconnecting cabling supplying power to the associated (continued)

Brunswick Unit 1 B 3.8-61 Rev'sion No. 6 I l

L m

DC Sources-Shutdown B 3.8.5

' BASES LC0 .

bus, needed to support required DC distribution subsystems (continued) required OPERABLE by LC0 3.8.8, " Distribution Systems-Shutdown," are required to be OPERABLE. In addition, DC control power for operation of two of the four 4.16 kV emergency buses and two of the four 480 V emergency buses, as well as control power for two of the four DGs, is provided by the Unit 2 DC electrical power subsystems.

Therefore, the Unit 2 DC electrical power subsystems needed to support required components are also required to be OPERABLE. Unit 2 DC electrical power subsystem OPERABILITY requirements are the same as those required for a Unit 1 DC electrical power subsystem. This requirement ensures the availability of sufficient DC electrical power sources to operate the unit in a safe manner and to mitigate the consequences of postulated events during shutdown (e.g.,

fuel handling accidents and inadvertent reactor vessel draindown).

APPLICABILITY The DC electrical power sources required to be OPERABLE in MODES 4 and 5 and during movement of irradiated fuel assemblies in the secondary containment provide assurance that:

a. Required features to provide adequate coolant inventory makeup are available for the irradiated fuel assemblies in the core in case of an inadvertent draindown of the reactor vessel;

b. Required features needed to mitigate a fuel handling accident are-available; l c. Required features necessary to mitigate the effects of l events that can lead to core damage during shutdown are available; and

d. Instrumentation and control capability is available for monitoring and maintaining the unit in a cold shutdown condition or refueling condition.

The DC electrical power requirements for MODES 1, 2, and 3 are covered in LCO 3.8.4.

(continued) l Brunswick Unit 1 B 3.8-62 Revision No. 6 1 i

r 1 l

j DC Sources-Shutdown B 3.8.5 BASES (continued) )

ACTIONS LC0 3.0.3 is not applicable while in MODE 4 or 5. However, since irradiated fuel assembly movement can occur in MODE 1, 2, or 3, the ACTIONS have been modified by a Note stating that LC0 3.0.3 is not applicable. If moving irradiated fuel assemblies while in MODE 4 or 5, LC0 3.0.3 would not specify any action. if moving irradiated fuel assemblies while in MODE 1, 2, or 3', the fuel movement is independent of reactor ,

operations. Entering LCO 3.0.3, while in MODE 1, 2, or 3, j would require the unit to be shutdown, but would not require immediate suspension of movement of irradiated fuel I

assemblies. The Note to the ACTIONS, "LC0 3.0.3 is not applicable," ensures that the actions for immediate -

, suspension of irradiated fuel assembly movement are not !

l postponed due to entry into LC0 3.0.3.

1 A.I. A.2.1. A.2.2. A.2.3. and A.2.4 1

If more than one DC distribution subsystem is required i according to LC0 3.8.8, the DC electrical power subsystems remaining 0PERABLE with one or more DC electrical power subsystems inoperable may be capable of supporting sufficient required features to allow continuation of CORE ALTERATIONS, fuel movement, and operations with a potential for draining the reactor vessel. By allowance of the option to declare required features inoperable with associated DC electrical power subsystem (s) inoperable, appropriate restrictions-are implemented in accordance with the affected system LCOs ACTIONS. However, in many instances, this option may involve undesired administrative efforts.

Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies in the_ secondary containment, and any activities that could result in inadvertent draining of the reactor vessel).

Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition.

These actions minimize the probability of the occurrence of postulated events. It is further required to immediately initiate action to restore the required DC electrical power subsystems and to continue this action until restoration is l accomplished in order to provide the necessary DC electrical i power to the plant. safety systems. I (continued) 1 Brunswick Unit 1 B 3.8-63 Revision No. 6 I i

DC Sources-Shutdown I

B 3.8.5 l~

BASES ACTIONS A.I. A.2.1. A.2.2. A.2.3. and A.2.4 (continued)

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. The restoration of the required DC electrical power subsystems should be completed as quickly as possible in order to minimize the time during which the plant safety systems may be without sufficient power.

l l l SURVEILLANCE SR 3.8.5.1 I l REQUIREMENTS SR 3.8.5.1 requires certain Surveillances required by LC0 3.8.4 to be met. Therefore, see the corresponding Bases for LC0 3.8.4 for a di;cussion of each SR.

This SR is modified by a Note. The reason for the Note is l to preclude requiring the OPERABLE DC sources from being discharged below their capability to provide the required power supply or otherwise rendered inoperable during the performance of SRs. It is the intent that these SRs must still be capable of being met, but actual performance is not required unless Unit 2 Specification 3.8.4, "DC l

Sources-Operating," requires performance of these SRs.

i When Unit 2 Specification 3.8.4 requires performance of i these SRs, DC source availability is not limited, due to the l

Unit 2 requirements for DC source OPERABILITY. Therefore, in this condition, other DC sources would be available to supply the required loads.

REFERENCES 1. UFSAR, Chapter 6.

2. UFSAR, Chapter 15. !

3. 10 CFR 50.36(c)(2)(ii). ;

I l

Brunswick Unit 1 B 3.8-64 Revision No. 6 I

4.

Battery Cell Parameters B 3.8.6 B 3.8 ELECTRICAL POWER SYSTEMS l

l B 3.8.6- Battery Cell Parameters l

L' BASES l

BACKGROUND This LC0 delineates the limits on electrolyte temperature, level, float voltage, and specific gravity for the DC electrical power subsystems batteries. A discussion of these batteries and their OPERABILITY requirements is provided in the Bases for LC0 3.8.4, "DC Sources-Operating," and LC0 3.8.5, "DC Sources-Shutdown."

APPLICABLE The initial conditians of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in UFSAR, Chapter 6 (Ra 1) and Chapter 15. (Ref. 2), assume Engineered Safet i Feature systems are OPERABLE. The DC electrical powar subsystems

provide normal and emergency DC electrical power for the diesel generators (DGs), 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 as discussed in l the Bases for'LC0 3.8.4 and LC0 3.8.5.

Since battery cell parameters support the operation of the DC electrical power subsystems, they satisfy Criterion 3 of ;

10 CFR 50.36(c)(2)(ii) (Ref. 3).

LC0 Battery cell parameters must remain with2n acceptable limits-to ensure availability of the required DC pcuer 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.

APPLICABILITY ~ The battery cell parameters are required solely for the support of the associated DC electrical power, subsystem.

Therefore, these cell parameters are only' required when the associated DC electrical power subsystem is required to be- H OPERABLE. Refer to the Applicability discussions in Bases for LC0 3.8.4 and LCO 3.8.5.

(continued)

I Brunswick Unit'.1 B 3 8-65 Revision No. 6 l l

Battery Cell Parameters B 3.8.6 BASES -(continued)

ACTIONS The ACTIONS Table is modified by a Note indicating that a separate Condition entry is allowed for each battery. This is-acceptable, since the Required Actions for each Condition provide appropriate compensatory actions for each battery with battery cell parameters not within limits. Complying with the Required Actions may allow for continued operation, and subsequent batteries with battery cell parameters not within limits are governed by subsequent Condition entry and application of. associated Required Actions.

A.l. A.2, and A.3 With parameters of one or more cells in one or more batteries not within limits (i.e., Category A limits not met or Category B limits not met, or Category A and B limits not met) but within the Category C limits specified in l Table 3.8.6-1, 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 continued operation is permitted for a limited period.

l The pilot cell (s) electrolyte level and float voltage are required to be verified to meet the Category C limits within I hour (Required Action A.1). This check provides 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 cell (s).

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 l 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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 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 parameteas are not severely degraded, this time is considered reasonable. The verification is repeated at l '

(continued)

Brunswick Unit 1 B 3.8-66 Revision No. 6 l 1

Battery Cell Parameters B 3.8.6 ,

BASES l

ACTIONS A.I. A.2. and A.3 (continued) 7 day intervals until the parameters are restored to ;

Category A and B limits. This periodic verification is l l consistent with the normal Frequency of pilot cell i Surveillances.

Continued operation prior to declaring the affected batteries inoperable is permitted for 31 days before battery l cell parameters must be restored to within Category A and B limits. Taking into 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 for operation prior to declaring the DC batteries inoperable.

1 )

l I

B.1 When any battery parameter is outside the Category C limit for any connected cell, sufficient capacity to supply the maximum expected loaJ requirement is not ensured and the corresponding DC electrical power subsystem must be declared l inoperable. Additionally, other potentially extreme conditions, such as any Required Action of Condition A and associated Completion Time not met or average electrolyte temperature of representative cells < 60*F, also are cause i for immediately declaring the associated DC electrical power j subsystem inoperable. '

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.

SR 3.8.6.2 The quarterly inspection of specific gravity and voltage is consistent with IEEE-450 (Ref. 4).

(continued)

Brunswick Unit 1 B 3.8-67 Revision No. 6 1

g Battery Cell Parameters B 3.8.6 BASES SURVEILLANCE ~ SR 3.8.6.3

, REQUIREMENTS.

l (continued)

This Surveillance verification that the average temperature l of representative cells is within limits is consistent with a recommendation of IEEE-450 (Ref. 4) that states that the i temperature of electrolytes in representative cells should l be determined on a' quarterly basis.

l l' 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's recommendations and the battery sizing calculations.

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 j designed pilot cell in each battery. The cells selected as ;

pilot cells are those whose temperature, voltage, and i electrolyte specific gravity approximate the state of charge '

of the entire battery.

The Category A limits specified for electrolyte level are based on manufacturer's recommendations and are consistent j with the guidance in IEEE-450 (Ref. 4), with the extra 1 i inch allowance above the high water level indication for i operating margin to account for temperature and charge !

effects. In addition to this allowance, Footnote (a) to Table 3.8.6-1 permits the electrolyte level to be temporarily above the specified maximum level during and following equalizing charge (i.e., for up to 3 days following the completion of an equalize charge), provided it is not overflowing. These limits ensure that the plates l suffer no physical damage, and that adequate electron l transfer capability is maintained in the event of transient ,

l 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

(continued)

Brunswick Unit 1 8 3.8-68 Revision No. 6 I L.

Battery Cell Parameters B 3.8.6

' BASES SURVEILLANCE Table 3.8.6-1 (continued)

REQUIREMENTS The Category A limit specified for float voltage is 2 2.13 V per cell. This value is based on the manufacturer's recommendations and on the recommendation of IEEE-450 (Ref. 4)', which states that prolonged operation of cells below 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's 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'F (25'C).

The specific gravity readings are corrected for actual electrolyte temperature and level. 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. Level correction will be in accordance with manufacturer's recommendations.

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 2 1.195 (0.020 below the manufacturer's fully charged, nominal specific gravity) with the average of all connected cells 21.205 (0.010 below the manufacturer's fully charged, nominal specific gravity). These values are based on l manufacturer's recommendations. The minimum specific gravity value required for each cell ensures that a cell with a marginal or unacceptable specific gravity is not masked by averaging cells having higher specific gravities. 1 Category C defines the limits for each connected cell. !

These values, although reduced, provide assurance that ;

sufficient capacity exists to perform the intended function l 1

(continued) l Brunswick Unit 1 B 3.8-69 Revision No. 6 l

g L Battery Cell Parameters

l. B 3.8.6 o

I

~

BASES SURVEILLANCE Table' 3.8.6-1 (continued)

REQUIREMENTS l

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 limit specified for electrolyte level (above the top of the plates and not overflowing) ensures that the plates suffer no physical damage and maintain adequate electron transfer capability. The Category C limit for l voltage is based on IEEE-450, Appendix C (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 on average specific gravity 21.195, is based on manufacturer's recommendations (0.020 below the 1

. manufacturer's 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 1 than 0.020 below the average of all connected cells. This {

limit ensures that a cell with a marginal or unacceptable i specific gravity is not masked by averaging with cells having higher specific gravities. 1 i

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

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 charging current is an acceptable alternative '

! to specific gravity measurement for determining the state of charge of the designated pilot cell. This phenomenon is discussed in IEEE-450 (Ref. 4). Footnote (c) allows the float charge current to be used as an alternate to specific ;

{ (continued)

'l Brunswick Unit 1 B 3.8-70 Revision No. 6 i L

Battery Cell Parameters B 3.8.6 i'

. BASES SURVEILLANCE- . Table 3.8.6-1 (continued)

, REQUIREMENTS 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 l

not follow a deep discharge) specific gravity gradients are not significant, and confirming measurements may be made in less than 7 days.

l REFERENCES 1. UFSAR, Chapter'6.

1

2. UFSAR, Chapter 15..

3. 10 CFR 50.36(c)(2)(ii).

4. IEEE Standard 450, 1987.

1 l

l l

Brunswick' Unit 1 'B 3.8-71 Revision No. 6 l L:

Distribution Systems-Operating B 3.8.7 B 3.8 ELECTRICAL POWER SYSTEMS j B 3.8.7 Distribution Systems-Operating 1

BASES- I BACKGROUND The onsite Class IE AC and DC electrical power distribution system is divided into redundant and independent AC and DC electrical power distribution subsystems.

The Class IE AC electrical distribution system is divided into four load groups. Each load group consists of a primary emergency bus, its downstream secondary emergency bus,120 VAC vital bus, and transformers and interconnecting cables. The buses associated with each of the four load groups are defined as follows:

Load group El consists of 4.16 kV bus El, 480 V l bus ES, and 120 VAC vital bus IES.

Load group E2 consists of 4.16 kV bus E2, 480 V bus E6, and 120 VAC vital bus 1E6.

Load group E3 consists of 4.16 kV bus E3, 480 V bus E7, and 120 VAC vital bus 2E7.

f

. Load group E4 consists of 4.16 kV bus E4, 480 V bus E8, and 120 VAC vital bus 2E8.

1 The El and E2 load groups are supplied from Unit 1 balance l

of plant (80P) buses and primarily serve Unit I loads. The E3 and E4 load groups are supplied from Unit 2 B0P buses and primarily serve Unit 2 loads. In some instances loads associated with one unit are'actually supplied from the opposite unit's load group buses. i Each primary emergency bus (4.16 kV emergency bus) has access to two offsite . sources of power via a common circuit path from its associated upstream B0P bus (master / slave ;

I breakers and interconnecting cables). In addition, each j

, 4.16 kV emergency bus can be provided power from an onsite ,

diesel generator (DG) source. The upstream B0P bus i associated with each 4.16 kV emergency bus is normally connected to the main generator output via the unit auxiliary transformer. During a loss of the normal power source to the 4.16 kV BOP bus, the preferred source supply !

breaker attempts to close. If all offsite sources are (continued)

I l Brunswick Unit 1 B 3.8-72 Revision No. 6 l

a.stribution Systems-0perating B 3.8.7 BASES BACKGROUND unavailable, the affected 4.16 kV emergency bus is isolated (continued) from its associated upstream 4.16 kV BOP bus and the onsite emergency DG will supply power to the 4.16 kV emergency bus.

Control power for each 4.16 kV emergency bus is supplied from a Class 1E battery with manual transfer capability to another Class 1E battery. Additional descriptions of this system may be found in the Bases for Specification 3.8.1, "AC Sources-0perating," and the Bases for Specification 3.8.4, "DC Sources-0perating".

The secondary plant distribution system includes 480 VAC emergency buses ES, E6, E7, and E8 and associated motor control centers (MCCs), transformers, and interconnecting cables. Secondary emergency buses ES, E6, E7, and E8 are supplied from primary emergency buses El, E2, E3, and E4, respectively. Control power for each 480 VAC emergency bus is supplied from a Class IE battery with manual transfer capability to another Class lE battery. Additional descriptions of this system may be found in the Bases for Specification 3.8.4, "DC Sources-0perating".

The 120 VAC vital buses 1E5, IE6, 2E7, and 2E8 are arranged in four load groups and are powered from secondary emergency buses E5, E6, E7, and E8, respectively.

l There are two independent 125/250 VDC electrical power distribution subsystems.

The list of required distribution buses is presented in l Table B 3.8.7-1.

l l

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

I systems are OPERABLE. The AC and DC electrical power ,

distribution systems are designed to provide sufficient l capacity, capability, redundancy, and reliability to ensure !

the availability of necessary power to ESF systems so that ;

the fuel, Reactor Coolant System, and containment design i limits are not exceeded. These limits are discussed in more I detail in the Bases for Section 3.2, " Power Distribution l Limits"; Section 3.5, " Emergency Core Cooling System (ECCS) and Reactor Cor.e Isolation Cooling (RCIC) System"; and Section 3.6, " Containment Systems."

(continued)

Brunswick Ur.it 1 B 3.8-73 Revision No. 6 l l

l

Wc L

Distribution Systems-0perating B 3.8.7 BASES APPL? CABLE ~ The OPERABILITY of the AC and DC electrical power SAFETY ANALYSES distribution subsystems is consistent with the initial (continued). assumptions of the accident analyses and is. based upon meeting the design basis of the unit. This includes

-maintaining distribution systems OPERABLE during accident conditions in the event of:

a. An assumed loss of all offsite power; and

b. A worst case single failure. )

l The AC and DC electrical power distribution system satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii) (Ref. 3).

LC0 The required electrical power distribution subsystems listed in Table B 3.8.7-1 ensure the availability of AC and DC electrical power for the systems required to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (A00) or a postulated DBA. The Unit 1 AC and DC electrical power distribution subsystems are required to be' OPERABLE. In addition, since i some components required by Unit I receive power through Unit 2 DC electrical power distribution subsystems (e.g.,

control _ pwer for two of the four 4.16 kV emergency buses, two of_the four 480 VAC emergency buses, and for two of the DGs, and two of four engineered safeguard system (ESS) panels), the Unit 2 DC electrical power distribution subsystems needed to support the required equipment must also be OPERABLE. As stated in Table B 3.8.7-1, each division of the AC and DC electrical power distribution systems is a subsystem.

I Maintaining the Division I and II AC and DC electrical power distribution subsystems OPERABLE ensures that the redundancy incorporated into the design of ESF is not defeated.

Therefore, a_ single failure within any. system or within the electrical power distribution subsystems will not prevent safe shutdown of the reactor.

The AC electrical power distribution subsystems require the associated buses and electrical _ circuits to be energized to their proper voltages. The DC electrical power distribution subsystems require the associated buses to be energized to i their proper voltage from either the associated batteries or chargers.

(continued)

Brunswick Unit 1 B 3.8-74 Revision No. 6 l LJ

p:-

l Distribution Systems-Operating B 3.8.7 BASES LC0 Based on the number of safety significant electrical loads (continued) associated with each bus listed in Table B 3.8.7-1, if one or more of the buses becomes inoperable, entry into the appropriate ACTIONS of LCO 3.8.7 is required. Other buses, such as MCCs and distribution panels, which help comprise the AC and DC distribution systems are not listed in I Table B 3.8.7-1. The loss of electrical loads associated l with these buses may not result in a complete loss of a l

redundant safety function necessary to shut down the reactor l and maintain it in a safe condition. Therefore, should one or more of these buses become inoperable due to a failure not affecting the OPERABILITY of a bus listed in Table B 3.8.7-1 (e.g. , a breaker supplying a- single MCC fails open), the individual loads on the bus must be declared inoperable, and the appropriate Conditions and Required Actions of the LCOs governing the individual loads would be entered. However, if one or more of these buses is inoperable due to a failure also affecting the OPERABILITY l of a bus listed in Table B 3.8.7-1 (e.g., loss of a 4.16 kV emergency bus, which results in de-energization of all buses powered from the 4.16 kV emergency bus), then although the individual loads are still considered inoperable, the Conditions and Required Actions of the LC0 for the l individual loads are not required to be entered, since LC0 3.0.6 allows this exception (i.e., the loads are inoperable due to the inoperability of a support system governed by a Technical Specification; the 4.16 kV emergency bus).

l In addition, tie breakers and transfer switches between redundant safoty related AC and DC power distribution subsystems, if they exist, must be open. This includes control power transfer switches associated with the 4.16 kV and 480 V emergency buses and transfer switches associated with the ESS and DG panels. This prevents any electrical

malfunction in any power distribution subsystem from i propagating to the redundant subsystem, which could cause the failure of a redundant subsystem and a loss of essential safety function (s). If any tie breakers are closed or l transfer switches aligned to the alternate supply, the affected redundant electrical power distribution subsystems are considered inoperable. This applies to the onsite, safety related, redundant electrical power distribution subsystems. It does not, however, preclude redundant Class IE 4.16 kV emergency buses from being powered from the

same offsite circuit.

(continued) l Brunswick Unit 1 B 3.8-75 Revision No. 6 l l

o n 1 Distribution Systems-0perating B 3.8.7 BASES (continued)

APPLICABILITY The electrical power distribution subsystems are required to be OPERABLE-in MODES 1, 2, and 3 to ensure that:

a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of'A00s or abnormal transients; and

b. Adequate core cooling is provided, and containment OPERABILITY and other vital functions are maintained in the event of a postulated DBA.

Electrical power distribution subsystem requirements for MODES 4 and 5 and other conditions in which AC and DC electrical power distribution subsystems are required are covered in the Bases for LC0 3.8.8, " Distribution Systems -Shutdown. "

ACTIONS A.1 With one AC electrical power distribution subsystem inoperable due to either inoperable load group E3 bus (es) or inoperable load group E4 bus (es), the remaining AC electrical power distribution load groups are capable of supporting the minimum safety functions necessary to shut down the operating reactor and maintain both reactors in a safe condition, assuming no single failure in the remaining AC electrical- power distribution load groups, when Unit 2 is-in MODE 4 or 5. (If Unit 2 is in MODE 1, 2, or 3, then the Unit 2 ACTIONS of Specification 3.8.7, " Distribution Systems-Operating," require restoration of the associated AC electrical power distribution subsystem within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months of the inoperability.) The overall reliability is reduced in Condition A, because a single failure in a remaining load group could result in the minimum required ESF functions not being supported. As a result, Required Action A.1 limits the time period to perform planned maintenance on a Unit 2 load group to 7 days. This is acceptable based on the following:

a. The other unit's load group buses are not as critical to the operating unit'(fewer operating unit loads) as i

'the' operating unit's load group buses. i

b. Performing maintenance on these components will j increase the reliability of the Class IE AC Electrical Power Distribution System. !

(continued) i

. Brunswick Unit 1 B 3.8-76 Revision No. 6 I

~

Distribution Systems-Operating B 3.8.7 l

BASES ACTIONS A.1 (continued) l

c. The 7 day Completion Time provides a reasonable time frame for performance of_ planned maintenance.

l During.the planned maintenance of the load group buses, if a l- condition is discovered on these buses requiring corrective l maintenance, this maintenance may be performed within the 7 day Completion Time of Required' Action A.1.

The Class 1E AC Electrical Power Distribution System is divided into four load groups. Each load group consists of a primary emergency bus, its downstream secondary emergency bus,120 VAC vital bus, and transformers and interconnecting cables. The buses associated with each of the four load L groups are defined as follows:

i Load group El consists of 4.16 kV bus El, 480 V l bus ES, and 120 VAC vital bus lES.

Load group E2 consists of 4.16 kV bus E2, 480 V bus E6, and 120 VAC vital bus IE6.

L'oad group E3 consists of 4.16 kV bus E3, 480 V bus E7, and 120 VAC vital bus 2E7.

Load group E4 consists of 4.16 kV bus E4, 480 V l- bus. E8, and 120 VAC vital bus 2E8.

l The second Completion Time for Required Action A.1 l establishes a limit on the maximum time allowed for any l

combination of required distribution subsystems to be inoperable during any single contiguous occurrence of failing to meet the LCO. If Condition A is entered while, for instance, an AC bus in a load group in a different division is inoperable and subsequently returned OPERABLE, this LCO may already have been not met for up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

l This situation could lead to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months l l (since initial failure to meet the LCO) to restore the AC Electrical Power Distribution System. At this time an AC bus in a load group in a different division could again become inoperable, and the load group removed under Condition A could be restored OPERABLE. This could continue indefinitely.

(continued)

Brunswick Unit I B 3.8-77 Revision No. 6 i j

Distribution Systems-0perating B 3.8.7 BASES ACTIONS. A.1 (continued)

This Completion Time allows for an exception to the normal

" time zero" for. beginning the allowed outage time " clock"..

This results in establishing the " time zero" at the time this LC0 was initially not met, instead of at the time Condition A was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Complotion Time is an acceptable limitation on this potential to fail to meet the LCO indefinitely.

If while in Condition A, emergency buses associated with another load group become inoperable (e.g., buses in load groups E3 and E4 are concurrently inoperable), Condition B and F must be entered, as appropriate.

.B.1 l With one or more required AC buses or distribution panels in one division inoperable for reasons other than Condition A, I the remaining AC electrical power distribution subsystems are capable of supporting the minimum safety functions necessary to shut dowa the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in the remaining AC electrical power distribution subsystems could result in the minimum required ESF functions not being supported. Therefore, the required AC buses and distribution panels must be restored to OPERABLE status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

The Condition B worst scenario is one division without AC l power (i.e., no offsite power to the division and the associated DG inoperable). In this Condition, the unit is more vulnerable to a complete loss of AC power. It is,-

therefore, imperative that the unit operators' attention be focused on minimizing the potential for loss of power to the remaining division by stabilizing the unit and restoring power to the affected division. The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months time limit before requiring a unit shutdown in this Condition is acceptable because of: ,

1 (continued) l l

l l

l Brunswick Unit 1 B 3.8-78 Revision No. 6 I i

Distribution Systems-0perating B 3.8.7 BASES ACTIONS B.1 (continued)

a. The potential for decreased safety if the unit operators' attention is diverted from the evaluations and actions necessary to restore power to the affected division to the actions associated with taking the unit to shutdown within this time limit.

b. The low potential for an event in conjunction with a single failure of a redundant component in the ,

division with AC power. (The redundant component is i verified OPERABLE in accordance with '

Specification 5.5.11 " Safety Function Determination Program (SFDP).")

The second Completion Time for Required Action B.1 i establishes a limit on the maximum time allowed for any '

combination of required distribution subsystems to be ,

inoperable during any single contiguous occurrence of failing to meet the LCO. If Condition B is entered while, for instance, a DC bus is inoperable and subsequently returned OPERABLE, this LC0 may already have been not met for up to 7 days. This situation could lead to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months , since initial failure to meet the '

LCO, to restore the AC electrical power distribution system.

At this time a DC bus could again become inoperable, and the AC electrical power distribution system could be restored OPERABLE. This could continue indefinitely.

This Completion Time allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

This results in establishing the " time zero" at the time this LC0 was initially not met, instead of at the time Condition B was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Completion Time is an acceptable limitation on this potential to fail to meet the LCO indefinitely.

C.1, C.2, C.3 and C.4 Condition C applies to the 125 VDC buses listed in Table B 3.8.7-1 which can be supplied from either a normal or an alternate DC source. These buses are listed below:

a. 125 VDC Control Power Buses for 4.16 kV Switchgear El, E2, E3, and E4; (continued)

Brunswick Unit 1 B 3.8-79 Revision No. 7 l

i Distribution Systems-0perating B 3.8.7 1

BASES i ACTIONS C.l. C.2. C.3 and C.4 (continued)

b. 125 VDC Control Power Buses for 480 V Switchgear E5, '

E6, E7, and E8;

c. 125 VDC ESS Logic Cabinets H58, H59, H60, and H61; and

d. 125 VDC DG Panels DG-1, DG-2, DG-3, and DG-4. I Condition A permits the de-energization of the E3 load group bus (es) or the E4 load group bus (es) for planned maintenance ,

when Unit 2 is in MODE 4 or 5. During a 4.16 kV or !

480 V bus outage it is desirable to clear both the normal and alternate sources of DC control power to the bus for personnel safety. The de-energized AC bus is inoperable and not capable of supplying its loads regardless of the availability of DC control power. Hence, entry into Condition C as a result of performing maintenance under l Condition A is not necessary; Condition D would apply. !

With one or more DC electrical power distribution subsystems inoperable due to loss of normal DC source, the remaining DC j electrical power distribution subsystem (s) are capable of supporting the minimum safety functions necessary to ,

shutdown the reactor and maintain it in a safe shutdown i condition, provided safety function is not lost and assuming no single failure. However, the overall reliability is ,

reduced because a single failure in the DC electrical power !

distribution cystem could result in a loss of two of four AC ,

electrical load groups and the minimum required ESF j functions not being supported. Therefore, action must be J immediately initiated to transfer the DC electrical power 1 distribution system to its alternate source and the affected !

supported equipment immediately declared inoperable. Upon completion of the transfer of the affected supported ]

1 equipment's DC electrical power distribution subsystem to its OPERABLE alternate DC source, the affected supported equipment may be declared OPERABLE again. The ESS logic cabinets transfer automatically upon loss of the normal i

source. For an ESS logic cabinet, verification that the automatic transfer has occurred and alternate power is available to the ESS logic cabinet will satisfy Required Action C.2. By allowance of the option to declare affected supported equipment inoperable with associated DC electrical power distribution subsystems inoperable due to loss of (continued)

Brunswick Unit 1 B 3.8-80 Revision No. 7 l

i Distribution Systems-0perating B 3.8.7 BASES ACTIONS C.I. C.2. C.3 and C.4 (continued) normal DC source, more conservative restrictions are implemented in accordance with the affected system LCOs' ACTIONS. When any control power transfer switch associated with the 4.16 kV and 480 V emergency buses or any transfer switch associated with the ESS and DG panels is transferred to the alternate source, a single failure in the DC system could render two of four AC electrical load groups inoperable. Therefore, to prevent indefinite operation in this degraded condition, power from the normal DC source must be restored in 7 days.

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention.

Required Actions C.1 and C.2 should be completed as quickly as possible. The 7 day Completion Time of Required Action C.4 is considered to be acceptable due to the low potential for an event in conjunction with a single failure of a redundant component and is consistent with the allowed Completion Time for an inoperable DC electrical power subsystem specified in Specification 3.8.4, "DC Sources-Operating."

The second Completion Time for Required Action C.4 establishes a limit on the maximum time allowed for any combination of required electrical power distribution subsystems to be inoperable during any single contiguous occurrence of failing to meet the LC0. If Condition C is entered while, for instance, an AC bus is inoperable and subsequently restored OPERABLE, the LC0 may already have been not met for up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . This situation could lead to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months , since initial failure to meet the LCO, to restore the DC electrical power distribution system. At this time, an AC bus could again become inoperable, and the DC electrical power distribution system could be restored OPERABLE. This could continue indefinitely.

This Completion Time allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

This allowance results in establishing the " time zero" at the time the LC0 was initially not met, instead of at the time Condition C was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Completion Time is an acceptable limitation on this potential of failing to meet the LC0 indefinitely.

(continued)

Brunswick Unit 1 B 3.8-81 Revision No. 7 l 1

Distribution Systems-Operating B 3.8.7 BASES ACTIONS M (continued)

With one DC electrical power distribution subsystem inoperable for reasons other than Condition C, the remaining DC electrical power distribution subsystem is capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in the remaining DC electrical power distribution subsystem could result in the minimum required ESF functions not being supported. Therefore, the required DC electrical power '

distribution subsystem must be restored to OPERABLE status within 7 days by powering the bus from the associated batteries or chargers.

Condition D represents one division without adequate DC power, potentially with both the battery (s) significantly degraded and the associated charger (s) nonfunctioning. In this situation the plant is significantly more vulnerable to a complete loss of all DC power. It is, therefore, imperative that the operator's attention focus on stabilizing the plant, minimizing the potential for loss of ,

power to the remaining divisions, and restoring power to the affected division. ,

The 7 day Completion Time is consistent with the allowed Completion Time for an inoperable DC electrical power j subsystem specified in Specification 3.8.4, "DC Sources-Operating". Taking exception to LCO 3.0.2 for components without adequate DC power, which would have Required Action Completion Times shorter than 7 days, is acceptable because of:

a. The potential for decreased safety when requiring a change in plant conditions (i.e., requiring a shutdown) while not allowing stable operations to continue;

b. The potential for decreased safety when requiring entry into numerous applicable Conditions and Required Actions for components without DC power, while not providing sufficient time for the operators to perform the necessary evaluations and actions for restoring power to the affected division; (continued)

Brunswick Unit I B 3.8-82 Revision No. 7 l

Distribution Systems-Operating B 3.8.7 BASES l

ACTIONS D.1 (continued)

\

l l c. The low potential for an event in conjunction with a I single failure of a redundant component. l The second Completion Time for Required Action D.1 establishes a limit on the maximum time allowed for any combination of required electrical power distribution subsystems to be inoperable during any single contiguous I occurrence of failing to meet the LC0. If Condition D is '

entered while, for instance, an AC bus is inoperable and subsequently restored OPERABLE, the LC0 may already have been not met for up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . This situation could lead to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months , since initial failure to meet the LCO, to restore the DC electrical power distribution system. At this time, an AC bus could again become inoperable, and.the DC electrical power distribution system could be restored OPERABLE. This could continue indefinitely.

This Completion Time allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

This allowance results in establishing the " time zero" at the time the LC0 was initially not met, instead of at the time Condition D was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Completion Time is an acceptable limitation on this potential of failing to meet the LC0 indefinitely.

J E.1 and E.2 If the inoperable electrical power distribution subsystem (s) l cannot be restored to OPERABLE status within the associated i Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the l required plant conditions from full power conditions in an orderly manner and without challenging plant systems. l (continued)

Brunswick Unit 1 B 3.8-83 Revision No. 7 l

Distribution Systems-0perating a B 3.8.7 BASES ACTIONS F.1 (continued)

Condition F corresponds to a level of degradation in 1.he electrical power distribution system that causes a required safety function to be lost. When more than one AC or DC electrical power distribution subsystem is lost, and this results in the loss of a required function, the plant is in a condition outside the accident analysis. Therefore, no additional time is justified for continued operation.

LC0 3.0.3 must be entered immediately to commence a controlled shutdown.

SURVEILLANCE SR 3.8.7.1 REQUIREMENTS This Surveillance verifies that the AC and DC electrical power distribution systems are functioning properly, with the correct circuit breaker alignment. This includes verifying that distribution bus tie breakers are open and control power transfer switches associated with the 4.16 kV and 480 V emergency buses and transfer switches associated with the ESS and DG panels are aligned to their normal DC sources. The correct breaker alignment ensures the appropriate separation and independence of the electrical buses are maintained, and power is available to each required bus. The verification of energization of the buses ensures that the required power is readily available for motive as well as control functions for critical system loads connected to these buses. This may be performed by verification of absence of low voltage alarms or by verifying a load powered from the bus is operating. The 7 day Frequency takes into account the redundant capability of the AC and DC electrical power distribution subsystems, and other indications available in the control room that alert the operator to subsystem malfunctions.

SR 3.8.7.2 This Surveillance verifies that no combination of more than two power conversion modules (consisting of either two u lighting inverters or one lighting inverter and one plant i uninterruptible power supply unit) are aligned to Division II (bus B). Two power conversion modules aligned i to Division II (bus B) was an initial assumption in the DC l battery load study. Limiting two power conversion modules (continued) 1 Brunswick Unit 1 B 3.8-84 Revision No. 7 l

r Dist -ibution Systems-Operating 8 3.8.7 )

BASES l SURVEILLANCE SR 3.8.7.2 (continued)

REQUIREMENTS j to be aligned to Division 11 ensures the associated J batteries will supply DC power to safety related equipment during a design basis event. The 7 day Frequency takes into I

account the redundant capability of the DC electrical )ower distribution subsystems. and indications available in tie control room to alert the operator of power conversion module misalignment.

REFERENCES- 1. UFSAR, Chapter 6.

2. UFSAR, Chapter 15.

3. 10 CFR 50.36(c)(2)(ii).

l l

Brunswick Unit 1 B 3.8-85 Revision No. 7 1

E Distribution Systems-Operating i- B 3.8.7 I ..

Table B 3.8.7-1 (page 1 of 1)

AC and DC Electrical Power Distribution Systems TYPE- VOLTAGE DIVISION I(a) DIVISION II(a) l AC emergency' 4160 V Emergency Bu::es Emergency Buses buses El, E3 E2, E4 480 V Emergency Buses Emergency Buses ES, E7 E6, E8 l AC' vital buses 120 V Distribution Distribution

! Panels Panels lES, 2E7 IE6, 2E8

DC buses 250 V Switchboard 1A Switchboard IB 125 V ESS logic ESS logic Cabinets Cabinets H58, H60 H59, H61

'125 V DG Panels DG Panels DG-1, DG-3 DG-2, DG-4 l DC control 125 V 4.16 kV Switchgear 4.16 kV Switchgear l power buses El, E3 E2,-E4 125 V 480 V 480 V l Switchgear Switchgear ES, E7 E6, E8 L (a). Each division of the AC and DC electrical power distribution systems is a subsystem.

l I

Brunswick Unit 1 B 3.8-86 Revision No. 7 l L

_m.

e Distribution Systems-Shutdown B 3.8.8 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.8 Distribution Systems-Shutdown BASES BACKGROUND A description of the AC and DC electrical power distribution system is provided in the Bases for LC0 3.8.7, " Distribution Systems-Operating."

APPLICABLE The initial conditions of Design Basis Accident and SAFETY ANALYSES transient analyses in the UFSAR, Chapter 6 (Ref.1) and Chapter 15 (Ref. 2), assume Engineered Safety Feature (ESF) systems are OPERABLE. The AC and DC electrical power distribution systems are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems so that the fuel, Reactor Coolant System, and containment design limits are not exceeded.

The OPERABILITY of the AC and DC electrical power distribution system is consistent with the initial assumptions of the accident analyses and the requirements for the supported systems' OPERABILITY.

The OPERABILITY of the minimum AC and DC elects , cal power sources and associated power distribution subsystems during MODES 4 and 5, and during movement of irradiated fuel assemblies in the secondary containment ensures that:

a. The facility can be maintained in the shutdown or refueling condition for extended periods;

b. Sufficient instrumentation and control capability is available for monitoring and maintaining the unit status; and

c. Adequate power is provided to mitigate events postulated during shutdown, such as an inadvertent draindown of the vessel or a fuel handling accident. j The AC and DC electrical power distribution systems satisfy !

Criterion 3 of 10 CFR 50.36(c)(2)(ii) (Ref. 3).

(continued) l Brunswick Unit 1 B 3.8-87 Revision No. 7 l

Distribution Systems-Shutdown B 3.8.8 BASES (continued)

LC0 Various combinations of subsystems, equipment, and components are required OPERABLE by other LCOs, depending on the specific plant condition. Implicit in those requirements is the required OPERABILITY of necessary support features. This LC0 explicitly requires energization of the portions of the electrical distribution system necessary to support OPERABILITY of Technical Specifications required systems, equipment, and components-both specifically addressed by their own LCO, and implicitly required by the definition of OPERABILITY. In addition, DC control power for operation of two of the four 4.16 kV emergency buses and two of the four 480 V emergency buses, as well as control power for two of the four diesel generators, is provided by the Unit 2 DC electrical power subsystems. Therefore, the Unit 2 DC electrical power distribution subsystems needed to support required components are also required to be OPERABLE.

In addition, it is acceptable for required buses to be cross-tied during shutdown conditions, permitting a single source to supply multiple redundant buses, provided the source is capable of maintaining proper frequency (if required) and voltage.

Maintaining these portions of the distribution system energized ensures the availability of sufficient power to operate the plant in a safe manner to mitigate the consequences of postulated events during shutdown (e.g.,

fuel handling accidents and inadvertent reactor vessel draindown).

APPLICABILITY The AC and DC electrical power distribution subsystems required to be OPERABLE in MODES 4 and 5 and during movement of irradiated fuel assemblies in the secondary containment provide assurance that:

a. Systems to provide adequate coolant inventory makeup are available for the irradiated fuel in the core in case of an inadvertent draindown of the reactor vessel;

b. Systems needed to mitigate a fuel handling accident are available; (continued)

Brunswick Unit 1 B 3.8-88 Revision No. 7 l

Distribution Systems-Shutdown B 3.8.8 BASES APPLICABILITY c. Systems necessary to mitigate the effects of l (continued) events that can lead to core damage during shutdown are available; and

d. Instrumentation and co.itrol capability is available for monitorino :nd maintaining the unit in a cold chutdown condition or refueling condition.

The AC and DC electrical power distribution subsystem requirements for MODES 1, 2, and 3 are covered in LC0 3.8.7.

ACTIONS LC0 3.0.3 is not applicable while in MODE 4 or 5. However, since irradiated fuel assembly movement can occur in MODE 1, 2, or 3, the ACTIONS have been modified by a Note stating that LC0 3.0.3 is not applicable. If moving irradiated fuel assemblies while in MODE 4 or 5, LCO 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, or 3, the fuel movement is independent of reactor operations. Entering LCO 3.0.3, while in MODE 1, 2, or 3, would require the unit to be shutdown, but would not require immediate suspension of movement of irradiated fuel assemblies. The Note to the ACTIONS, "LCO 3.0.3 is not applicable," ensures that the actions for immediate suspension of irradiated fuel assembly movement are not postponed due to entry into LC0 3.0.3.

I A.I. A.2.1. A.2.2. A.2.3. A.2.4. and A.2.5 l Although redundant required features may require redundant divisions of electrical power distribution subsystems to be OPERABLE, one OPERABLE distribution subsystem division may be capable of supporting sufficient required features to allow continuation of CORE ALTERATIONS, fuel movement, and operations with a potential fcr draining the reactor vessel.

By allowing the option to declare required features associated with an inoperable distribution subsystem inoperable, appropriate restrictions are implemented in accordance with the affected distribution subsystem LC0's Required Actions. In many instances this option may involve undesired administrative efforts. Therefore, the allowance for sufficiently conservative actions is made, (i.e., to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies in the secondary containment, and any activities that could result in inadvertent draining of the reactor vessel).

(continued)

Brunswick Unit 1 B 3.8-89 Revision No. 7 l

Distribution Systems-Shutdown B 3.8.8 BASES I

ACTIONS A.l. A.2.1. A.2.2. A.2.3 A.2.4 and A.2.5 (continued) '

Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition.

These actions minimize the probability of the occurrence of postulated events. It is further required to immediately initiate action to restore the required AC and DC electrical power distribution subsystems and to continue this action until restn ation is accomplished in order to provide the necenary power to the plant safety systems.

Notwithstanding performance of the above conservative Required Actions, a required residual heat removal-shutdown cooling (RHR-SDC) subsystem may be inoperable. In this case, Required Actions A.2.1 through A.2.4 do not adequately address the concerns relating to coolant circulation and heat removal. Pursuant to LC0 3.0.6, the RHR-SDC ACTIONS would not be entered. Therefore, Required Action A.2.5 is l provided to direct declaring RHR-SDC inoperable and not in operation, which results in taking the appropriate RHR-SDC ACTIONS.

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. The restoration of the required distribution subsystems should be completed as quickly as possible in order to minimize the l time the plant safety systems may be without power.

SURVEILLANCE SR 3.8.8.1 REQUIREMENTS This Surveillance verifies that the AC and DC electrical power distribution subsystems are functioning properly, with the correct breaker alignment. The correct breaker alignment ensures power is available to each required bus.

The verification of energization of the buses ensures that the required power is readily available for motive as well as control functions for critical system loads connected to these buses. This may be performed by verification of the I absence of low voltage alarms or by verifying a load powered from the bus is operating. The 7 day Frequency takes into account the redundant capability of the electrical power i distribution subsystems, as well as other indications l available'in the control room that alert the operator to subsystem malfunctions. l (continued) l Brunswick Unit 1 B 3.8-90 Revision No. 7 I

Distribution Systems-Shutdown B 3.8.8

-.' BASES . (continued) .

REFERENCES- 1. UFSAR, Chapter 6.

2. UFSAR, Chapter 15, 3.- 10 CFR 50.36(c)(2)(ii).

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I Brunswick Unit 1 B 3.8-91 Revision No. 7 l

Bases Unit 2 - B 2.0 - B 3.3 Replacement Pages I

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p i RPS Instrumentation B 3.3.1.1 BASES l 4 SURVEILLANCE SR 3.3.1.1.6 and SR 3.3.1.1.7 i REQUIREMENTS'

! (continued) These Surveillances are established to ensure that no gaps in neutron flux indication exist from subcritical to power operation for monitoring core reactivity status.

l The overlap between SRMs and IRMs is required to be l

I demonstrated to ensure that reactor power will not be increased into a neutron flux region without adequate indication. This 's required prior to withdrawing SRMs from the fully insertes position since indication is being transitioned frow the SRMs to the IRMs.

The overlap between IRMs and APRMs is of concern when reducing powe- into the IRM range. On oower increases, the system design will prevent further increases (by initiating

, a rod block) if aoiquate overlap is not maintained. Overlap between IRMs and APids exists when sufficient IRMs and APRMs concurrently have onscale readings such that the transition between MODE I and MODE 2 can be made without either APRM downscale rod block, or IRM upscale rod block. Overlap ,

between SRMs and IRMs si.nilarly exists when, prior to withdrawing the SRMs from the fully inserted position, IRM i readings have doubled before the SRMs have reached the )

high-high upscale trip.

As noted, SR 3.3.1.1.7 is only required to be met during 1 entry into MODE 2 from MODE 1. That is, after the overlap requirement has been met and indication has transitioned to the IRMs, maintaining overlap is not required (APPMs may be reading downscale once in MODE 2).

If overlap for a group of channels is not demonstrated (e.g., IRM/APRM overlap), the reason for the failure of the Surveillance should be determined and the appropriate channel (s) declared inoperable. Only those appropriate channels that are required in the current MODE or condition should be declared inoperable.

A Frequency of 7 days is reasonable based on engineering judgment and the reliability of the IRMs and APRMs.

(continued) l J

Brunswick Unit 2 B 3.3-30 Revision No. 2 l

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PAM Instrumantation ;

B 3.3.3.1 i BASES LCO 3. Suppression Chamber Water level (continued) 1 of the ECCS suction lines to 5 feet above the normal pool water level. Two wide range suppression pool water level signals are transmitted from separate differential pressure transmitters for each channel. The out)ut of one of these i channels is recorded on a recorder in tie control room. The output of the other channel is read on an indicator in the control room. These instruments are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals specifically with this portion of the ;

instrument channel. ;

4. Suppression Chamber Water Temoerature Suppression chamber water temperature is a Type A and Category I variable provided to detect a condition that could potentially lead to containment breach and to verify l the effectiveness of ECCS actions taken to prevent

, containment breach. The suppression chamber water temperature instrumentation, which measures from 40*F to 240*F, allows operators to detect trends in suppression pool water temperature in sufficient time to take action to prevent steam quenching vibrations in the suppression pool.

Suppression pool temperature is monitored by 24 (12 per division) tencerature sensors spaced around the suppression ,

pool. A pair of sensors (one per division) is located near l each of the quenchers on the discharge lines of the 11 safety / relief valves. Each pair of sensors is located so as to sense the representative temperature of that sector of the suppression pool even with the associated safety / relief i valve open. The outputs for the sensors are indicated on )

l two microprocessors in the control room. The signals from l the sensors are conditioned by the two microprocessors to l provide an average water temperature. A minimum of 11 out i of 12 sensors are required to provide this average per l division. Average water temperature is recorded on two independent recorders in the control room. These recorders l are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals specifically with this portien of the instrument channels. '

, (continued) 1

.Bronswick Unit 2 B 3.3-77 Revision No. 3 l l

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PAM Instrumentation B 3.3.3.1 BASES LCO 5. Suppression Chamber Pressure (continued)

Suppression chamber pressure is a Type A and Category I variable provided to detect a condition that could potentially lead to containment breach and to verify the effectiveness of ECCS actions taken to prevent containment breach. Suppression chamber pressure is indicated in the control room from two separate pressure transmitters. The range of indication is O psig to 75 psig. These instruments are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals specifically with this portion of the instrument channel.

6. Drywell Pressure Drywell pressure is a Type A and Category I variable provided to detect breach of the RCPB and to verify ECCS functions that operate to maintain RCS integrity. Two wide range drywell pressure signals are transmitted from separate pressure transmitters for each channel. The output of one of these channels is recorded on a recorder in a control room. The output of the other channel is read on an indicator in the control room. The pressure channels measure from -5 psig to 245 psig. These instruments are the primary indication used by the operator during an accident.

Therefore, the PAM Specification deals specifically with this portion of the instrument channel.

7. Drvwell Temperature Drywell temperature is a Type A and Category I variable provided to detect a breach of the RCPB and to verify the effectiveness of ECCS functions that operate to maintain RCS integrity. Twenty (20) temperature sensors (10 per division) are located in the drywell and suppression pool atmosphere. In order to provide adequate monitoring of the entire air space, a minimum of I sensor per monitoring location, 5 per division are required (Ref. B 3.6.1.4, SR 3.6.1.4.1 for monitoring locations). The sensors are i divided into two divisions for redundancy, The signals from l these sensors are conditioned by two divisionalized microprocessors. Drywell temperature is recorded by two pairs of divisionalized recorders in the control room. The range of the recorders is from 40'F to 440*F. These (continued)

Brunswick Unit 2 B 3.3-78 Revision No. 3 l

PAM Instrumentation B 3.3.3.1 BASES LCO 7. Drywell Temperature (continued) I recorders are the primary indication used by the operator during an accident. Therefore, the PAM Specification deals specifically with this portion of the instrument channel.

1 Primary Containment Isolation Valve (PCIV) Position PCIV position, a Category I variable, is provided for verification of containment integrity. In the case of PCIV position, the important information is the isolation status of the containment penetration. The LC0 requires one channel of valve position indication in the control room to be OPERABLE for each active PCIV in a containment penetration flow path, i.e., two total channels of PCIV position indication for a penetration flow path with two active valves. For containment penetrations with only one - i active PCIV having control room indication, Note (b) {

requires a single channel of valve position indication to be .

OPERABLE. This is sufficient to redundantly verify the I isolation status of each isolable penetration via indicated status of the active valve, as applicable, and prior knowledge of passive valve or system boundary status. If a penetration flow path is isolated, position indication for the PCIV(s) in the associated penetration flow path is not needed to determine status. Therefore, the position indication for valves in an isolated penetration flow path is not required to be OPERABLE.

The PCIV position PAM instrumentation consists of position switches, associated wiring and control room indication for active PCIVs-(check valves and manual valves are not required to have position indication). Therefore, the PAM l Specification deals specifically with these instrument channels.

9. Drywell and Suppression Chamber Hydrocen and Oxvoen Analyzers Drywell and suppression chamber hydrogen and oxygen analyzers are Type A and Category I instruments provided to detect high hydrogen or oxygen concentration conditions that (continued)

Brunswick Unit 2 B 3.3-79 Revision No. 3.I

PAM Instrumentation B 3.3.3.1 BASES LCO 9. Drywell and Suopression Chamber Hydroaen and OxYQen Analyzers (continued) represent a potential for containment breach. This variable is also important'in verifying the adequacy of mitigating actions. The drywell and suppression chamber hydrogen and oxygen analyzers PAM instrumentation consists of two independent gas analyzer systems. Each gas analyzer system consists of a hydrogen analyzer and an oxygen analyzer. The analyzers are capable of determining hydrogen concentration in the range of 0% to 30% and oxygen concentration in the range of 0% to 25%. Each gas analyzer system must be capable of sampling the drywell and the suppression chamber.

There are two independent recorders in the control room to display the results. Therefore, the PAM Specification deals specifically with these portions of the analyzer channels.

10. Drywell Area Radiation Drywell area radiation is a Category I variable provided to monitor the potential of significant radiation releases and to provide release assessment for use by operators in determining the need to invoke site emergency plans. Post accident drywell area radiation levels are monjtored by four instruments, each with a range of 1 R/hr to 10 R/hr. The outputs of these channels are indicated and recorded in the control room. Therefore, the PAM Specification deals j specifically with this portion of the instrument channel.

APPLICABILITY The PAM instrumentation LC0 is applicable in MODES 1 and 2.

These variables are related to the diagnosis and preplanned actions required to mitigate DBAs. The applicable DBAs are assumed to occur in MODES 1 and 2. In MODES 3, 4, and 5, plant conditions are such that the likelihood of an event j that would require PAM instrumentation is extremely low;

! therefore, PAM instrumentation is not required to be OPERABLE in these MODES.

l ACTIONS Note I has been added to the ACTIONS to exclude the MODE change restriction of LC0 3.0.4. This exception' allows entry into the applicable MODE while relying on the ACTIONS even though the ACTIONS may eventually require plant (continued)

Brunswick Unit 2 8 3.3-80 Revision No. 3 1

PAM Instrumentation B 3.3.3.1 l

L BASES l

ACTIONS shutdown. This exception is acceptable due to the passive (continued) function of the instruments, the operator's ability to diagnose an accident using alternative instruments and methods, and the low probability of an event requiring these instruments.

, Note 2 has been provided to modify the ACTIONS related to l PAM instrumentation channels. Section 1.3, Completion l Times, specifies that once a Condition has been entered, subsequent divisions, subsystems, components, or variables expressed in the Condition discovered to be inoperable or not within limits, will not result in separate entry into l the condition. Section 1.3 also specifies that Required Actions of the Condition continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for inoperable PAM instrumentation channels provide appropriate compensatory measures for separate Functions. As such, a Note has been provided that allows separate Condition entry for each inoperable PAM Function.

M When one or more Functions have one required channel that is l inoperable, the required inoperable channel must be restored l to OPERABLE status within 30 days. The 30 day Completion Time is based on operating experience and takes into account

, the remaining OPERABLE channels, the passive nature of the instrument (no critical automatic action is assumed to occur from these. instruments), and the low probability of an event

! requiring PAM instrumentation during this interval.

M If a channel has not been restored to OPERABLE status in l 30 days, this Required Action specifies initiation of action in accordance with Specification 5.6.6, which requires a l written report to be submitted to the NRC. This report discusses the results of the root cause evaluation of the inoperability and identifies proposed restorative actions.

This Required Action is appropriate in lieu of a shutdown requirement, since another OPERABLE channel is monitoring !

the Function, and given the likelihood of plant conditions l that would require information provided by this !

instrumentation.

(continued) i Brunswick Unit 2 B 3.3-81 Revision No. 3 l 1

PAM Instrumentation B 3.3.3.1 BASES ACTIONS C.1 (continued)

When one or scre Functions have two required channels that are inoperable (i.e., two channels inoperable in the same Function), one channel in the Function should be restored to OPERABLE status within 7 days. The Completion Time of 7 days is based on the relative.ly low probability of an event requiring PAM instrument operation and the availability of alternate means to obtain the required information. Continuous operation with two required channels inoperable in a Function is not acceptable because the alternate indications may not fully meet all performance qualification requirements applied to the PAM instrumentation. Therefore, requiring restoration of one inoperable channel of the Function limits the risk that the PAM Function will be in a degraded condition should an accident occur.

Q.d This Required Action directs entry into the appropriate Condition referenced in Table 3.3.3.1-1. The applicable Condition referenced in the Table is function dependent.

Each time an inoperable channel has not met the Required Action of Condition C and the associated Completion Time has expired, Condition D is entered for that channel and provides for transfer to the appropriate subsequent Condition.

f.d For the majority of Functions in Table 3.3.3.1-1, if any Required Action and associated Completion Time of Condition C is not met, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

(continued)

Brunswick Unit 2 B 3.3-82 Revision No. 3 l

PAM Instrumentation 8 3.3.3.1 BASES ACTIONS f.d (continued)

Since alternate means of monitoring primary containment area radiation are available, the Required Action is not to shut down the plant, but rather to follow the directions of Specification 5.6.6. These alternate means may be temporarily installed if the normal PAM channel cannot be restored to OPERABLE status within the allotted time. The report provided to the NRC should discuss the alternate means used, describe the degree to which the alternate means are equivalent to the installed PAM channels, justify the areas in which they are not equivalent, and provide a schedule for restoring the normal PAM channels.

SURVEILLANCE As noted at the beginning of the SRs, the following SRs REQUIhEMENTS apply to each PAM instrumentation Function in Table 3.3.3.1-1.

SR 3.3.3.1.1 Performance of the CHANNEL CHECK once every 31 days ensures that a gross failure of instrumentation has not occurred. A CHANNEL CHECK is normally a comparison of the parameter indicated on one channel against a similar parameter on other channels. It is based on the assumption that i instrument channels monitoring the same parameter should i read approximately the same value. Significant deviations i between instrument channels could be'an indication of excessive instrument drift in one of the channels or something even more sericus. A CHANNEL CHECK will detect gross channel failure; thus, it is key to verifying the instrumentation continues to operate properly between each l CHANNEL CALIBRATION. The high radiation instrumentation should be compared to similar plant instruments located throughout the plant.

Agreement criteria are determined by the plant staff, based on a combination of the channel instrument uncertainties, including indication and readability. If a channel is outside the criteria, it may be an indication that the _

sensor or the signal processing equipment has drifted outside its limit.

(continued)

Brunswick Unit 2 B 3.3-83 Revision No. 3 l

PAM Instrumentation B 3.3.3.1 BASES SURVEILLANCE SR 3.3.3.1.1 (continued)

REQUIREMENTS The Frequency of 31 days is based upon plant operating experience, with regard to channel OPERABILITY and drift, which demonstrates that failure of more than one channel of a given function in any 31 day interval is rare. The CHANNEL CHECK supplements less formal, but more frequent, checks of channels during normal operational use of those displays associated with the channels required by the LCO.

SR 3.3.3.1.2 and SR 3.3.3.1.3 These SRs require a CHANNEL CALIBRATION to be performed.

CHANNEL CALIBRATION is a complete check of the instrument loop, including the sensor. The test verifies the channel responds to measured parameter with the necessary range and accuracy. For Function 9, the CHANNEL CALIBRATION shall be performed using standard gas samples containing a nominal:

a. Zero volume percent hydrogen, balance nitrogen;

b. . Seven to ten volume percent hydrogen, balance nitrogen;

c. Twenty-five to thirty volume percent hydrogen, balance nitrogen;

d. Zero volume percent oxygen, balance nitrogen;

e. Seven to ten volume percent oxygen, balance nitrogen; and

f. Twenty to twenty-five volume percent oxygen, balance nitrogen.

For Function 10, the CHANNEL CALIBRATION shall consist of an electronic calibration of the channel, not including the detector, for range decades above 10 R/hr and a one point calibration check of the detector below 10 R/hr with an installed or portable gamma source.

The 92 day Frequency for CHANNEL CALIBRATION of the drywell and suppression chamber hydrogen and oxygen analyzers is based on operating experience. The 24 month Frequency for (continued) i Brunswick' Unit 2 B 3.3-84 Revision No. 3 l

PAM Instrumentation B 3.3.3.1 BASES SURVEILLANCE SR 3.3.3.1.2 and SR 3.3.3.1.3 (continued)

REQUIREMENTS CHANNEL CALIBRATION of all other PAM Instrumentation of Table 3.3.3.1-1 is based on operating experience and consistency with the BNP refueling cycles.

REFERENCES 1. Regulatory Guide 1.97, Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident, i Revision 2, December 1980. l l

2. NRC Safety Evaluation Report, Conformance to l Regulatory Guide 1.97, Rev. 2, Brunswick Steam Electric Plant, Units 1 and 2, May 14,1985.

3. 10 CFR 50.36(c)(2)(ii).

Brunswick Unit 2 8 3.3-85 Revision No. 3 l

7 Primary Containment Isolation Instrumentation B 3.3.6.1 BASES APPLICABLE 2.a. Reactor Vessel Water level-Low level 1 (continued) l' SAFETY ANALYSES, i

LCO, and. Reactor Vessel Water Level-Low Level 1 Function are l APPLICABILITY. .available and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation l

function.

l

.The Reactor Vessel Water Level-Low Level 1 Allowable Value was chosen to be the same as the RPS Level 1 scram Allowable.

Value'(LCO 3.3.1.1), since isolation of these valves is not critical to orderly plant shutdown. The Allowable Value is referenced from reference level zero. Reference level zero is 367 inches above the vessel zero point.

l This Function isolates the Group 2, 6, and 8 valves. l

, 2.b. Drywell Pressure-Hiah

! High drywell pressure can indicate a break in the RCPB l inside the prirr.ary containment. The isolation of some of the primary containment isolation valves on high drywell pressure supports actions to ensure that offsite dose limits of 10 CFR 100 are not exceeded. . The Drywell Pressure-High Function, associated with isolation of the primary

. containment, is implicitly assumed in the UFSAR accident analysis as these leakage paths are assumed to be isolated post LOCA.

High drywell pressure signals are initiated from pressure transmitters that sense the pressure in the drywell. Four channels of Drywell Pressure-High Function are available and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

The Allowable Value was selected to be the same as the ECCS Drywell Pressure-High Allowable Value (LCO 3.3.5.1), since this may be indicative of a LOCA inside primary containment.

This Function isolates the Group 2 and 6 valves. This Function in conjunction with reactor low pressure also isolates Group 10 valves.

L (continued) l l

l Brunswick Unit 2 B 3.3-154 Revision No. 5 l l

l Primary Containment Isolation Instrumentation B 3.3.6.1 BASES APPLICABLE 3.c. 4.c. HPCI and RCIC Steam Supp1v Line Pressure--Low SAFETY ANALYSES, LCO, and The steam line low pressure function is provided so that APPLICABILITY the steam isolation valves are automatically closed after (continued) reactor steam pressure is below that at which HPCI or RCIC can effectively operate. This closure ensures that long term containment leakage rates are within limits after a LOCA.

The HPCI and RCIC Steam Supply Line Pressure-Low signals are initiated from pressure switches (four for HPCI and four for RCIC) that are connected to the system steam line. Four channels of both HPCI and RCIC Steam Supply Line Pressure-Low Functions are available and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

The Allowable Values are selected to be below the pressure at which the system's turbine can effectively operate. The Allowable Values are also selected to be above the peak expected drywell pressure to ensure that an elevated drywell pressure during a LOCA does not prevent timely closure of the valves.

These Functions isolate the Group 4 and 5 valves, as appropriate.

3.d. 4.d. HPCI and RCIC Turbine Exhaust Diaphraam Pressure-Hiah High turbine exhaust diaphragm pressure could indicate that the turbine rotor is not turning, thus allowing reactor pressure to act on the turbine exhaust line. The HPCI and RCIC Turbine Exhaust Diaphragm Pressure-High Functions initiate isolation to prevent overpressurization of the turbine exhaust line. These isolations are for eouipment protection and are not assumed in any transient or accident analysis in the UFSAR. These instruments are included in the TS because of the potential for risk due to possible failure of the instruments preventing HPCI and RCIC initiations. Therefore, they meet criterion 4 of Reference 4.

(continued)

P 'inswick Unit 2 B 3.3-157 Revision No. 4 l

1 Bases Unit 2 - B 3.4 - B 3.10 Replacement Pages i

l LIST OF EFFECTIVE PAGES - BASES Paae No. Revision No. Page No. Revision No.

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Brunswick Unit 2 LOEP-1 Revision 7 l

i LIST OF EFFECTIVE PAGES - BASES (continued) :

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(continued) l Brunswick Unit 2 L0EP-2 Revision 3 l l j

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B 3.7-34 0' B 3.8 34 6 i B 3.7-35 0 B 3.8-35 6 B 3.7-36 0 B 3.8-36 6 B 3.7-37 0 8 3.8-37 6 B.3.7-38 0 8 3.8-38 6 B 3.7-39 0 8 3.8-39 6 l (continued) !

l Brunswick Unit 2 L0EP-3 Revision 6 l o

LIST OF EFFECTIVE PAGES - BASES (continued)

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B 3.8-40 6 8 3.8-81 7 B 3.8-41 6 B 3.8-82 7 B 3.8-42 6 B 3.8-83 7 B 3.8-43 6 B 3.8-84 7 B 3.8-44 6 B 3.8-85 7 B 3.8-45 6 B 3.8-86 7 8 3.8-46 6 B 3.8-87 7 B 3.8-47 6 B 3.8-88 7 B 3.8-48 6 B 3.8-89 7 B 3.8-49 6 B 3.8-90 7 B 3.8-50 6 B 3.8-91 7 8 3.8-51 6 B 3.8-52 6 B 3.9-1 0 B 3.8-53 6 B 3.9-2 0 B 3.8-54 6 B 3.9-3 0 B 3.8-55 6 B 3.9-4 0 B 3.8-56 6 B 3.9-5 0 B 3.B-57 6 B 3.9-6 0 B 3.8-58 6 8 3.9-7 0 B 3.8-59 6 B 3.9-8 0 B 3.8-60 6 B 3.9-9 0 B 3.8-61 6 B 3.9-10 0 B 3.8-62 6 8 3.9-11 0 B 3.8-63 6 B 3.9-12 0 0 3.8-64 6 8 3.9-13 0 B 3.8-65 6 B 3.9-14 0 B 3.8-66 6 B 3.9-15 0 B 3.8-67 6 B 3.9-16 0 B 3.8-68 6 8 3.9-17 0 B 3.8-69 6 B 3.9-18 0 B 3.8-70 6 B 3.9-19 0 B 3.8-71 6 B 3.9-20 0 B 3.8-72 6 8 3.9-21 0 B 3.8-73 6 B 3.9-22 0 B 3.8-74 6 B 3.9-23 0 B 3.8-75 6 B 3.9-24 0 B 3.8-76 6 8 3.9-25 0 B 3.8-77 6 B 3.9-26 0 ,

B 3.8-78 6 B 3.9-27 0 B 3.8-79 7 B 3.9-28 0 B 3.8-80 7 8 3.9-29 0 (continued) .

-Brunswick Unit 2 L0EP-4 Revision 7 i I

LIST OF EFFECTIVE PAGES - BASES (continued)

Pace No. Revision No,

.B 3.10-1 0 B 3.10-2 0 B 3.10-3; O B 3.10-4i 0 B 3.10-5 0 B 3.10-6 0 8 3.10-7 0 B 3.10-8 0 B 3.10-9 0 B 3.10-10 0 B 3.10-l' 0 B 3.10-12 0 B 3.10-13 0 8 3.10-14 0 B 3.10 15 0 B 3.10-16 0 B 3.10-17 0 8 3.10-18 0 B 3.10-19 0 B 3.10-20 0 B 3.10-21 0 B 3.10-22 0 i B 3.10-23 0 I B 3.10-24 0 B 3.10-25 0 B 3.10-26 0 l 8 3.10-27 0 ;

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TABLE OF CONTENTS B 3.7 PLANT SYSTEMS (continued)

B 3.7.4 Control Room Air Conditioning (AC) System .... B 3.7-27 B 3.7.5 Main Condenser Offgas .............. B 3.7-32 B 3.7.6 Main Turbine Bypass System . . . . . . . . . . . . B 3.7-35 B 3.7.7. Spent Fuel Storage Pool Water Level ....... B 3.7-39 B 3.8 ELECTRICAL POWER SYSTEMS .............. B 3.8-1 B 3.8.1 AC Sources-Operating .............. B 3.8-1

~B 3.8.2 AC Sources--Shutdown . . . . . . . . . . . . . . . B 3.8-35 B 3.8.3 Diesel Fuel Oil ................. B 3.8-42 B 3.8.4 DC Sources-Operating .............. B 3.8-50 B 3.8.5 DC Sources-Shutdown ............... B 3.8-61 B 3.8.6 Battery Cell Parameters ............. B 3.8-65 i B 3.8.7 Distribution Systems-0perating ......... B 3.8-72 B 3.8.8 Distribution Systems-Shutdown . . . . . . . . . . B 3.8-87 l B 3.9 REFUELING OPERATIONS ................ B 3.9-1 l B 3.9.1 Refueling Equipment Interlocks . . . . . . . . . . B 3.9-1 B 3.9.2 Refuel Position One-Rod-Out Interlock ...... B 3.9-5 l B 3.9.3 Control Rod Position . . . . . . . . . . . . . . . B 3.9-9 i B 3.9.4 Control Rod Position Indication ......... B 3.9-12 B 3.9.5 Control Rod OPERABILITY-Refueling . . . . . . . . B 3.9-16 B 3.9.6 Reactor Pressure Vessel (RPV) Water Level .... B 3.9-19 8 3.9.7 Residual Heat Removal (RHR)-High Water Level .. B 3.9-22 B 3.9.8 Residual Heat Removal (RHR)-Low Water Level . . . B 3.9-26 B 3.10 SPECIAL OPERATIONS ................. B 3.10-1 B 3.10.1 Inservice Leak and Hydrostatic Testing. Operation . B 3.10-1 B 3.10.2 Reactor Mode Switch Interlock Testing ...... B 3.10-6 B 3.10.3 Single Control Rod Withdrawal-Hot Shutdown ... B 3.10-11 B 3.10.4 Single Control Rod Withdrawal-Cold Shutdown . . . B 3.10-16 8 3.10.5 Single Control Rod Drive (CRD) Removal-Refueling B 3.10-21 B 3.10.6 Multiple Control Rod Withdrawal-Refueling . . . . B 3.10-26 8 3.10.7 Control Rod Testing-Operating . . . . . . . . . . B 3.10-29 B 3.10.8 SHUTDOWN MARGIN (SDM) Test-Refueling ...... B 3.10-33 Brunswick Unit 2 ii Revision No. 7 l l 1

J

1

)

Recirculation Loops Operating B 3.4.1 BASES l

l I

1 APPLICABLE A plant specific LOCA analysis has been performed assuming l SAFETY ANALYSES only one operating recirculation loop. This analysis has (continued) demonstrated that, in the event of a LOCA caused by a pipe break in the operating recirculation loop, the Emergency .

Core Cooling Syst u response will provide adequate core I cooling, without the requirement to modify the APLHGR requirements (Ref. 3). However, the COLR may require APLHGR limits to restrict the peak clad temperature for a LOCA with a single recirculation loop operating below the s corresponding temperature for both loops operating.

The transient analyses of Chapter 15 of the UFSAR have also i been performed for single recirculation loop operation (Ref. 3) and demonstrate sufficient flow coastdown j characteristics to maintain fuel thermal margins during the abnormal operational transients analyzed without the requirement to modify the MCPR requirements. During single recirculation loop operation, modification to the Reactor Protection System (RPS) average power range monitor (APRM) instrument setpoints may be required to account for the 1 different relationships between recirculation drive flow and reactor core flow by depressing a switch on the flow control trip reference cards of the APRM Flow Biased Simulated Thermal Power-High instrumentation. This manual action will adjust the flow control trip reference card to the setpoint map for single recirculation loop operation.

However, in accordance with Reference 3, no modifications to the APRM Flow Biased Simulated Thermal Power-High setpoint are currently required.

Recirculation loops operating satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii) (Ref. 4).

LC0 Two recirculation loops are normally required to be in operation with their recirculation pump speeds matched within the limits specified in SR 3.4.1.1 to ensure that during a LOCA caused by a break of the piping of one recirculation loop the assumptions of the LOCA analysis are satisfied. Alternately, with only one recirculation loop in operation, modifications to the required APLHGR limits (LC0 3.2.1, " AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR)"), MCPR limits (LCO 3.2.2, " MINIMUM CRITICAL POWER RATIO (MCPR)"), and APRM Flow Biased Simulated Thermal Power-High setpoint (LC0 3.3.1.1), as applicable, must be applied to allow continued operation. However, based on the (continued)

Brunswick Unit 2 B 3.4-3 Revision No. 1 l

l Recirculation Loops Operating B 3.4.1 BASES LCO analyses in Reference 3, no modifications to the MCPR (continued) limits or APRM Flow Blased Simulated Thermal Power-High setpoint are required for the current operating cycle. For the current cycle APLHGR power- and flow-dependent multipliers are required to be applied as described in the COLR. j APPLICABILITY In MODES I and 2, requirements for operation of the Reactor l Coolant Recirculation System are necessary since there is i considerable energy in the reactor core and the limiting i design basis transients and accidents are assumed to occur.

In MODES 3, 4, and 5, the consequences of an accident are reduced and the coastdown characteristics of the ;

recirculation loops are not important. l ACTIONS A_d With the requirements of the LC0 not met, the recirculation loops must be restored to cperation with matched recirculation pump speeds within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months . A recirculation loop is considered not in operation when the pump in that loop is idle or when the difference in pump speeds of the l two recirculation pumps is greater than the match criteria. 1 The loop with the lower recirculation pump speed must be considered not in operation. Should a LOCA occur with one recirculation loop not in operation, the core flow coastdown and resultant core response may not be bounded by the LOCA analyses. - Therefore, only a limited time is allowed to restore the inoperable loop to operating status.

Alternatively, if the single loop requirements of the LCO .

are applied to operating limits and RPS setpoints, as !

applicable, operation with only one recirculation loop would satisfy the requirements of the LCO and the initial conditions of the accident sequence.

The 6 hour6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Completion Time is based on the low probability of an accident occurring during this time period, on a reasonable time to complete the Required Action (i.e., reset the applicable limits or setpoints for single recirculation loop operation), and on frequent core monitoring by operators allowing abrupt changes in core flow conditions to be quickly detected.

(continued)

Brunswick Unit 2 8 3.4-4 Revision No. 1 l

Recirculation loops Operating B 3.4.1 BASES ACTIONS- M (continued)

This Required Action does not require tripping the recirculation pump with the lowest pump speed when the pump speeds between the two recirculation pumps are greater than the match criteria. However, in cases where large deviations from the recirculation pump speed match criteria occur, low flow or reverse flow can occur in the recirculation loop jet pumps associated with the lower speed recirculation pump, causing vibration of the jet pumps. If zero or reverse flow is detected, the condition should be alleviated by changing pump speeds to re-establish forward flow.

M !

With no recirculation loops in operation or the Required l Action and associated Completion Time of Condition A not !

met, the plant must be brought to a MODE in which the LCO )

does not apply. To achieve this status, the plant must be 1 brought to MODE-3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . In this condition, the :

recirculation loops are not required to be operating because !

of.the reduced severity of DBAs and minimal dependence on the recirculation loop coastdown characteristics. The allowed Completion Time of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is reasonable, based on operating experience, to reach MODE 3 from full power ,

conditions in an orderly manner and without challenging I plant systems.

SURVEILLANCE SR 3.4.1.1 REQUIREMENTS ,

This SR ensures the recirculation pump speeds are within the ,

allowable match criteria. At low core flow (i.e., < 75% of t rated core flow), the MCPR requirements provide larger margins to the fuel cladding integrity Safety Limit such that the potential- adverse effect of early boiling transition during a.LOCA is reduced. A larger difference between recirculation pump speeds can therefore be allowed when core flow is < 75% of rated core flow. The recirculation pump speed match criteria, as used in this Surveillance, conservatively corresponds to recirculation ,

loop flow match criteria. The 10% match criterion in terms of recirculation pump speed conservatively equates to the 5%

match criterion.in terms of recirculation loop flow and the (continued)

Brunswick Unit 2 8 3.4-5 Revision No. 1 l

Recirculation loops Operating B 3.4.1 l l

l BASES SURVEILLANCE SR 3.4.1.1 (continued)

REQUIREMENTS 20% match criterion in terms of recirculation pump speed conservatively equates to the 10% match criterion in terms of recirculation loop flow. The generator speed associated with the recirculation pump motor-generator set may be used to measure recirculation pump speed. l The match criteria are measured in terms of the percent l difference between recirculation pump speeds. If the '

difference between the recirculation pump speeds exceeds the match criteria, the loop with the lower recirculation pump speed is considered not in operation. The SR is not required when both loops are not in operation since the ,

match criteria are meaningless during single loop or natural l circulation operation. The Surveillance must be performed i within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after both loops are in operation. The l 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Frequency is consistent with the Surveillance Frequency for jet pump OPERABILITY verification and has been shown by operating experience to be adequate to detect off normal recirculation pump speeds in a timely manner. :

REFERENCES 1. UFSAR, Section 5.4.1.3.

2. UFSAR, Chapter 15.

3. NEDC-31766P, Brunswick Steam Electric Plant Units 1 and 2 Single Loop Operation, February 1990.

4. 10 CFR 50.36(c)(2)(ii).

Brunswick Unit 2 B 3.4-6 Revision No. 1 l

l i

AC Sources-Operating !

B 3.8.1 l

)

l BASES l

ACTIONS B.1 (continued)

Required Action B.1 addresses actions to be taken in the event of inoperability of redundant required features concurrent with two offsite circuits inoperable due to one Unit 1 B0P circuit path to the downstream 4.16 kV emergency bus being inoperable and the DG associated with the downstream 4.16 kV emergency bus inoperable. When applying Required Action B.1, the Configuration Risk Management Program described in Technical Requirements Manual 5.5.13 is required to be implemented. Condition B is intended to be used for planned maintenance on the Unit 1 B0P' buses and the

' associated 4.16 kV emergency bus-(in order to perform maintenance on the 4.16 kV emergency bus, the associated DG must be rendered inoperable). Redundant required features failures consist of inoperable features that are associated with an emergency bus redundant to the emergency bus with inoperable offsite circuits and DG. Required Action B.1 reduces the vulnerability to a loss of function. An example of inoperable redundant required feature is as follows. If one Unit 2 core spray subsystem becomes inoperable while planned maintenance is being performed on a Unit 1 B0P bus and the associated emergency buses, the Unit 2 RHR subsystem associated with the inoperable Unit 1 emergency bus must immediately be declared inoperable since a core spray subsystem is a redundant required feature to an RHR subsystem for the purposes of core cooling. As a result, the applicable Conditions of Specification 3.5.1, "ECCS-Operating," shall be entered and Required Actions !

performed. If at any time during the existence of this condition, an additional Unit 2 or Unit 1 offsite source or DG becomes inoperable, Condition 1 of Unit 2 Specification 3.8.1 must be entered and the associated Required-Actions performed.

The immediate Completion Time for Required Action B.1 is l l

intended to ensure that all redundant required features are i OPERABLE, or required features ACTIONS entered, prior to I entering Condition B. This Completion Time also allows for I an exception to the normal " time zero" for beginning the ;

allowed outage time " clock". In this Required Action, the i Completion Time only begins on discovery that both:

a. Two Unit .1 offsite circuits are inoperable due to one inoperable Unit 1 B0P circuit path to the downstream 4.16 kV emergency bus and the DG associated with the

. downstream.4.16 kV emergency bus is inoperable; and (continued)

' Brunswick Unit 2' 'B 3.8-6 Revision No. 6 1 l

AC Sources-Operating ,

B 3.8.1 l BASES ACTIONS B.1 (continued) 1

b. A redundant required feature is inoperable. '

If, at any time during the existence of this Condition, a l redundant required feature subsequently becomes inoperable, this Completion Time begins to be tracked.

Condition B is modified by two notes. Note 1 only allows ,

this Condition to be used when the opposite unit is in MODE 4 or 5. When two offsite circuits are inoperable, due to one Unit 1 B0P circuit path and the DG associated with the downstream 4.16 kV emergency bus inoperable, while Unit 1 is in MODE 1, 2, or 3, Condition I of Unit 2 <

Specification 3.8.1 must be entered and the associated Required Actions performed. Note 2 prevents Condition B from being entered coincident with Condition A (i.e., the SAT or UAT shall not be inoperable coincident with a B0P ,

circuit path and the associated DG). The Unit 1 BOP buses 2C and 20 can each be supplied from the Unit 1 offsite circuits (SAT and UAT). Inoperability of the Unit 1 SAT or UAT, as provided for in Condition A, would result in the loss of redundancy of offsite power to the operable B0P bus if Condition A and B were allowed to be entered coincidentally. If at any time Condition A is entered coincident with Condition B, Condition I of Unit 2 Specification 3.8.1 must be entered and the associated Required Actions performed.

B.2 The Unit 1 BOP buses 1C and 10 can each be supplied from the two Unit 1 offsite circuits (SAT and UAT). In turn, offsite power is supplied from each B0P bus to its downstream 4.16 kV emergency bus via a single circuit. Hence, an intentional outage of a B0P bus or the circuit path to its associated emergency bus (master / slave breakers and interconnecting cables) results in the loss of availability of both offsite circuits to the downstream emergency bus.

The phrase " balance of plant circuit path to the downstream 4.16 kV emergency bus" as stated in Condition B refers to the B0P bus and its associated circuit path (master / slave breakers and interconnecting cables) to the downstream 4.16 kV emergency bus.

(continued)

Brunswick Unit 2 B 3.8-7 Revision No. 6 1

1 AC Sources-0perating B 3.8.1 BASES ACTIONS B.2 (continued)

To ensure highly reliable power sources remain with one Unit 1 balance of plant circuit path to the downstream 4.16 kV emergency bus inoperable and the DG associated with the downstream 4.16 kV emergency bus inoperable, it is necessary to verify the availability of the remaining offsite circuits on a more frequent basis. Since the Required Action only specifies " perform," a failure of SR 3.8.1.1' acceptance criteria does not result in the Required Action not met. However, if a second circuit fails SR 3.8.1.1, the second offsite circuit is inoperable, and Condition E, for two or more offsite circuits inoperable, is entered.

B.3 This Required Action provides a 7 day time period to perform planned maintenance on one of these B0P buses and the circuit path to its associated 4.16 kV emergency bus when Unit 1 is in MODE 4 or 5. During the planned maintenance of the 80P bus, the associated emergency bus and the associated DG, if a condition is discovered on these buses or the DG requiring corrective maintenance, this maintenance may be performed within the 7 day time period of Required Action B.3. (If Unit 1 is in MODE 1, 2, or 3, then the Unit 1 ACTIONS of Specification 3.8.1, "AC Sources-Operating," require entry into LC0 3.0.3 for this condition.) The 7 day Completion Time takes into account the capacity and capability of the remaining AC sources and a reasonable time-frame for performance of planned maintenance. This is acceptable because maintenance on each B0P bus and the circuit path to its associated emergency bus will increase the reliability of the offsite circuits to the downstream 4'.16 kV emergency buses. It should be noted that while in this condition each of the remaining three 4.16 kV emergency buses will have their standby emergency source and two sources of offsite power OPERABLE. If one or both sources of offsite power are lost to an additional 4.16 kV emergency bus then Condition E is entered.

The second Completion Time for Required Action B.3 establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet (continued)

Brunswick Unit-2 8 3.8-8 Revision No. 6 l L.

AC Sources-0perating B 3.8.1 BASES ACTIONS B.3 (.ontinutd)

LC0 3.8.1.a or b. If Condition B is entered while, for instance, an offsite circuit is inoperable and that circuit is subsequen'.ly restored OPERABLE, the LC0 may already have been not met for up to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . This situation could lead to a total af 10 days from initial failure of the LC0 to restoratior. of the B0P circuit path to the downstream 4.16 kV emargency bus and DG associated with the affected 4.16 kV eraergency bus. At this time, a second offsite circuit'could again become inoperable, the BOP circuit path to the downstream 4.16 kV emergency bus and DG associated with the affected 4.16 kV emergency bus restored OPERABLE, and an additional 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months (for a total of 13 days) allowed ;

prior to complete restoration of the LCO. The 10 day Completion Time provides a limit on the time-allowed in a specified condition after discovery of failure to meet LC0 3.8.1.a or b. This limit is considered reasonable for situations in which Condition B and Condition C or D are entered concurrently. The "AND" connector between the 7 day and 10 day Completion Time means that both Completion Times apply simultaneously, and the more restrictive must be met.

As in Required Action B.1, the second Completion Time allows for an exception to the normal " time zero" for beginning the allowed outage time " clock". This exception results in establishing the " time zero" at the time that LC0 3.8.1.a or b was initially not met, instead of the time that Condition B was entered.

C.1 I To ensure a highly reliable power source remains with one offsite circuit inoperable, it is necessary to verify the availability of the remaining offsite circuits on a more frequent basis. Since the Required Action only specifies

" perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action not met. However, if a second circuit fails SR 3.8.1.1, the second offsite circuit is inoperable, and Condition E, for two or more offsite I circuits inoperable, is entered.

(continued) i Brunswick Unit 2 B 3.8-9 Revision No. 6 i

AC Sources-0perating B 3.8.1 BASES i

-ACTIONS C.2 (continued)

Required Action C.2, which only applies if one 4.16 kV emergency bus cannot.be powered from an offsite source, is intended to provide assurance that an. event with a coincident single failure of the associated DG does not result. in a complete loss of safety function of critical systems. . These features (e.g., system, subsystem, division, component,.or. device) are designed with redundant safety. !

related 4.16 kV emergency buses. . Redundant. required feature failures consist of inoperable features associated with an l emergency bus redundant to the emergency bus that has no !

offsite power. !

l The Completion Time for Required Action C.2 is. intended to l l allow time for the operator to evaluate and repair any l discovered inoperabilities. This Completion Time also '

allows an exception to the normal " time zero" for beginning the allowed outage time " clock." In this Required Action the Completion Time only begins on discovery that both

a. A 4.16 kV emergency bus has no offsite power supplying i its loads; and I

b. A redundant required feature on another emergency bus is inoperable.

I If, at any time during the existence of this Condition.(one l offsite circuit inoperable)'a redundant required feature-subsequently becomes inoperable, this Completion Time would begin to be tracked. ,

i Discovering no offsite. power to one 4.16 kV emergency bus of i the onsite Class lE Power Distribution System coincident with one or more inoperable required support or supported features, or both, that are associated with any other emergency bus that has offsite power, results in starting l

.the Completion Times for the Required Action. Twenty-four hours-is acceptable because it minimizes risk while allowing l time for restoration before the unit is subjected to- a transients associated with shutdown. l (continued)-

Brunswick Unit 2 B 3.8-10 Revision No. 6 l

r AC Sources-0perating B 3.8.1 BASES ACTIONS C.2 (continued) l The remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to the onsite Class lE Distribution System. Thus, on a component basis, single failure protection may have been lost for the required feature's function; however, function is not lost.- The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Completion Time takes into account the component OPERABILITY of the redundant counterpart to the inoperable required feature. Additionally, the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion ' Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

C_-1 l According to Regulatory Guide 1.93 (Ref. 9), operation may continue in Condition C for a period that should not exceed l 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . With one offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the plant safety systems. In this condition, however, the remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to the onsite Class lE Distribution System.

The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time.for repairs, and the low probability of a DBA occurring during this period.

The second Completion Time for Required Action C.3 l l establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet ,

LC0 3.8.1.a or b. If Condition C is entered while, for I instance, a DG is inoperable, and that DG is subsequently l returned OPERABLE, the LCO may already have been not met for 4 up to 7 days. This situation could lead to a total of 10 days, since initial failure to meet the LCO, to restore the offsite circuit. At this time, a DG could again become inoperable, the circuit restored OPERABLE, and an additional 7 days -(for a total of 17 days) allowed prior to complete restoration of the LCO. The 10 day Completion Time provides (continued)

Brunswick Unit 2 B 3.8-11 Revision No. 6 I

AC Sources-0perating B 3.8.1 BASES ACTIONS C.3 (continued) I a limit on the time allowed in a specified condition after discovery of failure to meet LC0 3.8.1.a or b. This limit is considered reasonable for situations in which Conditions C and D are entered concurrently. The "AND" l connector between the 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months and 10 day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.

As in Required Action C.2, the Completion Time allows for an I exception to the normal " time zero" for beginning the allowed outage time " clock." This exception results in establishing the " time zero" at the time LC0 3.8.1.a or b was initially not met, instead of at the time that Condition C was entered. 1 0.1 1 To ensure a highly reliable power source remains with one DG inoperable, it is necessary to verify the availability of the offsite circuits on a more frequent basis. Since the Required Action only specifies " perform," a failure to meet SR 3.8.1.1 acceptance criteria does not result in a Required Action being not met. However, if a circuit fails to pass SR 3.8.1.1, it is inoperable. Upon offsite circuit inoperability, additional Conditions must then be entered.

D.2 1 Required Action D.2 is intended +n provide assurance that a loss of offsite. power, during the perica tnat a DG is inoperabic, does not result in a complete loss of safety function of critical systems. These features are designed to be powered from redundant safety related 4.16 kV emergency buses (i.e., single division systems are not included). Redundant required feature failures consist of inoperable features associated with an emergency bus redundant to the emergency bus that has an inoperable DG.

(continued) i i

Brunswick Unit 2 B 3.8-12 Revision No. 6 I

AC Sources-Operating B 3.8.1 BASES ACTIONS D.2 (continued) l The Completion Time is intended to allow the operator time to evaluate and repair any discovered inoperabilitie . This Completion Time also allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

In this Required Action the Completion Time only begins on discovery that both:

a. An inoperable DG exists; and

b. A redundant required feature on another emergency bus is inoperable.

If, at any time during the existence of this Condition (one DG inoperable), a required redundant feature subsequently becomes inoperable, this Completion Time begins to be tracked.

Discovering one DG inoperable coincident with one or more inoperable required support or supported features, or both, that are associated with the OPERABLE DGs results in starting the Completion Time for the Required Action. Four hours from the discovery of these events existing concurrently is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.

The remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class IE Distribution System. Thus, on a component basis, single failure protection for the required feature's function may have been lost; however, function has not been lost. The 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Completion Time takes into account the component OPERABIllTY of the redundant counterpart to the inoperable required feature. Additionally, the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

(continued)

Brunswick Unit 2 B 3.8-13 Revision No. 6 1 i

AC Sources-Operating B 3.8.1 BASES ACTIONS D.3.1 and 0.3.2 (continued)

Required Action D.3.1 provides an allowance to avoid unnecessary testing of OPERABLE DGs. If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DG, SR 3.8.1.2 does not have to be performed. If the cause of inoperability exists on other DG(s).-they are declared inoperable upon discovery, and Condition G or I of LCO 3.8.1 is entered, as applicable. 1 Once the failure is repaired, and the common cause failure no longer exists, Required Action D.3.1 is satisfied. If I the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of SR 3.8.1.2 suffices to provide assurance of continued OPERABILITY of those DGs.

In the event the inoperable DG is restored to OPERABLE status prior to completing either D.3.1 or D.3.2 (i.e., the I inoperable DG has been restored to OPERABLE status but it has not yet been determined if the cause of the inoperability is common to the other OPERABLE DGs), the CP&L Corrective Action Program (CAP) will continue to evaluate the common cause possibility. This continued evaluation, however, is no longer required under the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months constraint imposed while in Condition D. 1 According to Generic Letter 84-15 (Ref. 10), 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is a reasonable time to confirm that the OPERABLE DGs are not affected by the same problem as the inoperable DG.

D.4 l The 4.16 kV emergency bus design is sufficient to allow operation to continue in Condition D for a period that should not exceed 7 days. In Condition D, the remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class lE Distribution System.

The 7 day Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

(continued)

Brunswick Unit 2 B 3.8-14 Revision No. 6 l

AC Sources-Operating B 3.8.1 BASES ACTIONS D.4 (continued)

The second Completion Time for Required Action D.4 establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet LC0 3.8.1.a or b. If Condition D is entered while, for I instance, an offsite circuit is inoperable and that circuit is subsequently restored OPERABLE, the LC0 may already have been not met for up to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . This situation could lead to a total of 10 days, since initial failure of the LC0, to restore the DG. At this time, an offsite circuit could again become inoperable, the DG restored OPERABLE, and an additional 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months (for a total of 13 days) allowed prior to complete restoration of the LCO. The 10 day Completion Time provides a limit on the time allcwed in a specified condition after discovery of failure to meet LCO 3.8.1.a or b. This limit is considered reasonable for situations in which Conditions C and D are entered concurrently. The l "AND" connector between the 7 day and 10 day Completion Times means that both Completion Times apply simultaneously, and the more restrictive must be met.

As in Required Action D.2, the Completion Time allows for an i exception to the normal " time zero" for beginning the allowed outage time " clock." This exception results in establishing the " time zero" at the time that LC0 3.8.1.a or b was initially not met, instead of the time that Condition D was entered. l E.1 and E.2 Required Action E.1 addresses actions to be taken in the event of inoperability of redundant required features concurrent with inoperability of two or more offsite circuits. Required Action E.1 reduces the vulnerability to I a loss of function. The Completion Time for taking these actions is reduced to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months from that allowed with one 4.16 kV emergency bus without offsite power (Required Action C.2). The rationale for the reduction to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is I that Regulatory Guide 1.93 (Ref. 9) allows a Completion Time of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for two offsite circuits inoperable, based upon the assumption that two complete safety divisions are OPERABLE. While this Action allows more than two circuits (continued _1 Brunswick linit 2 B 3.8-15 Revision No. 6 1

AC Sources-Operating B 3.8.1 BASES ACTIONS E.1 and E.2 (continued) I to be inoperable, Regulatory Guide 1.93 (Ref. 9) assumes only two circuits are required by' the LCO, and a loss of those two circuits results in a total loss of offsite power to the Class lE Electrical Power Distribution System. Thus, i with the BNP electrical design, a loss of the four offsite circuits results in the same condition assumed in Regulatory Guide 1.93 (Ref. 9). When a concurrent redundant required feature failure exists, this assumption is not the case, and a shorter Completion Time of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is appropriate. These i features are designed with redundant safety related 4.16 kV I emergency buses, (i.e., single division systems are not included in the list). Redundant required feature failures consist of any of these features that are inoperable because any inoperability is on an emergency bus redundant to an emergency bus with inoperable offsite circuits.

The Completion Time for Required Action E.1 is intended to I allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal " time zero" for beginning the . allowed outage time " clock." In this Required Action, the Completion Time only begins on discovery that both:

-a. Two or more offsite circuits are inoperable; and

b. A redundant required feature is inoperable.

If, at any time during the existence of this Condition (any combination of two or more Unit 1 and 2 offsite circuits inoperable), a redundant required feature subsequently l becomes inoperable, this Completion Time begins to be tracked.

According to Regulatory Guide 1.93 (Ref. 9), operation may continue.in Condition E for a period that should not exceed I !

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . This level of degradation means that the offsite i electrical power system may not have the capability to :

effect a safe shutdown and to mitigate the effects of an '

accident; however, the onsite AC sources have not been j degraded. This level of degradation generally corresponds to a total loss of the immediately accessible offsite power sources.

(continued) i l

Brunswick Unit 2 8 3.8-16 Revision No. 6 l

1 AC Sources-Operating B 3.8.1 BASES ACTIONS E.1 and E.2 (continued) l Because of the normally high availability of the offsite sources, this level of degradation may appear to be more severe than other combinations of two AC sources inoperable that-involve one or more DGs inoperable. However, two factors tend to decrease the severity of this degradation level:

a. The configuration of the redundant AC electrical power system that remains available is not susceptible to a single bus or switching failure; and

b. The time required to detect and restore an unavailable offsite power source is generally much less than that required to detect and restore an unavailable onsite AC source.

With two or more of the offsite circuits inoperable, sufficient onsite AC sources are available to maintain the unit in a safe shutdown condition in the event of a DBA or transient. In fact, a simultaneous loss of offsite AC sources, a LOCA, and a worst case single failure were postulated as a part of the design basis in the safety analysis. Thus, the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time provides a period of time to effect restoration of all but one of the offsite circuits commensurate with the importance of maintaining an AC electrical power system capable of meeting its design criteria.

According to Regulatory Guide 1.,93 (Ref. 9), with the I available offsite AC sources two less than required by the !

LCO, operation may continue for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If all offsite ;

sources are restored within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , unrestricted operation l may continue. If all but one offsite source is restored within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , power operation continues in accordance with Condition A or C, as applicable. I F.1 and F.2 l Pursuant to LC0 3.0.6, the Distribution System-Operating ACTIONS would not be entered even if all AC sources to it l were inoperable, resulting in de-energization. Therefore, the Required Actions of Condition F are modified by a Note I (continued)

Brunswick Unit 2 B 3.8-17 Revision No. 6 1

1 AC Sources-Operating B 3.8.1 BASES ACTIONS F.1 and F.2 (continued) to indicate that when Condition F is entered with no AC source to any 4.16 kV emergency bus, ACTIONS for LC0 3.8.7,

" Distribution. Systems-0perating," must be immediately entered. This allows Condition F to provide requirements I for the loss of an offsite circuit and one DG without regard to whether an emergency bus is de-energized. LC0 3.8.7 provides the appropriate restrictions for a de-energized emergency bus.

According to Regulatory Guide 1.93 (Ref. 9), operation may continue in Condition F for a period that should not exceed 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . In Condition F, individual redundancy is lost in both the offsite electrical power system and the onsite AC electrical power system. Since power system redundancy is provided by two diverse sources of power, however, the reliability of the power systems in this Condition may appear higher than that in Condition E (loss of two or more 1 offsite circuits). This difference in reliability is offset by the susceptibility of this power system configuration to a single bus or switching failure. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

G.1 I With two or more DGs inoperable and an assumed loss of offsite electrical power, insufficient standby AC ' sources are available to power the minimum required ESF functions.

Since the offsite electrical power system is the only source of AC power for the majority of ESF equipment at this level of degradation, the risk associated with continued operation for a very short time could be less than that associated with an immediate controlled shutdown. (The immediate shutdown could cause grid instability, which could result in a total loss of AC power.) Since any inadvertent unit generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation is severely restricted. The intent here is to avoid the risk associated with an immediate controlled shutdown and to minimize the risk associated with this' level of degradation.

(continued)

Brunswick Unit 2 B 3.8-18 Revision No. 6 I

y AC Sources-Operating B 3.8.1 BASES-ACTIONS- G.1 (continued) l

' According to Regulatory Guide 1.93 (Ref. 9), with two or more DGs inoperable, operation may continue for a period that should not' exceed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . While this Action allows more than two DGs to be inoperable, Regulatory Guide 1. 93 (Ref. 9) assumes only two DGs are required by the LCO, and a loss of those two DGs results in a total loss of onsite power to the Class IE Electrical Power Distribution System.

Thus, with' the' BNP electrical design, a loss of the _ four DGs results in the same condition assumed in Regulatory Guide 1.93 (Ref. 9).

H.1 and H.2 -l

~If the inoperable AC electrical power sources cannot be restored to OPERABLE status within the associated. Completion Time, the unit must be brought to a MODE in which the LC0 does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

I.1 Condition I corresponds to a level of degradation in which all redundancy in the AC electrical power supplies has been lost. At this severely degraded level, any further losses in the AC electrical ~ power system may cause a loss of function. Therefore, no additional time is justified for continued operation. The unit is required by LC0 3.0.3 to

. commence a controlled shutdown.

SURVEILLANCE The AC sources are designed to permit inspection and

REQUIREMENTS testing of all important areas and features, especially those that have a standby function, in accordance with UFSAR Sections 8.2 and 8.3 (Ref. 2). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions). The SRs for (continued) i Brunswick Unit 2 B 3.8-19 Revision No. 6 I i

i

AC Sources-Operating B 3.8.1 l BASES SURVEILLANCE demonstrating the OPERABILITY of the DGs are consistent with REQUIREMENTS the recommendations of Safety Guide 9 (Ref. 5), Regulatory (continued) Guide 1.9 (Ref.11), and Regulatory Guide 1.137 (Ref.12),

as addressed in the UFSAR.

Where the SRs discussed herein specify voltage and frequency tolerances, the following summary is applicable. The minimum steady state output voltage of 3750 V is derived from the recommendations found in. Safety Guide 9 (Ref. 5) and bounds the minimum steady state output voltage criteria of 3621 V associated with the 4.16 kV emergency buses l analyzed in the AC Auxiliary Electrical Distribution System Study. This value (3621 V) allows for voltage drop to the l terminals of 4000 V motors whose minimum operating voltage is specified as 3600 V. It also allows for voltage drops to motors and other equipment down through the 480 V level where minimum operating voltage is also usually specified as 90% of name plate rating. The specified maximum steady state output voltage of 4300 V ensures the maximum operating voltage at the safety related 480 V substations is no more than the maximum rated steady state voltage criteria for the 480 V motor control centers. The maximum steady state output voltage was determined taking into consideration the voltage drop between the DGs and the 4.16 kV emergency buses and a 5% voltage boost at the 480 V substation transformers.

This maximum steady state output voltage also ensures that for a lightly loaded distribution -system, the voltage at the terminals of 4000 V motors is no more than the maximum rated steady state operating voltage. The specified minimum and maximum frequencies of the DG are 58.8 Hz and 61.2 Hz, respectively. These values are equal to 2% of the 60 Hz nominal frequency and are derived from the recommendations found in Safety Guide 9 (Ref. 5).

SR 3.8.1.1 This SR ensures proper circuit continuity for the offsite AC electrical power supply to the onsite distribution network and availability of offsite AC electrical power. The breaker alignment verifies that each breaker is in its correct position to ensure that distribution' buses and loads are connected to'their preferred power source and that appropriate independence of offsite circuits is maintained.

The 7 day Frequency is adequate since breaker position is not likely to change without the operator being aware of it and because its status is displayed in the control room.

(continued)

Brunswick' Unit 2 B 3.8-20 Revision No. 6 i

h AC Sources-0perating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.7 REQUIREMENTS-(continued) These SRs help to ensure the availability of the standby electrical power supply to mitigate DBAs and transients and I maintain the unit in a safe shutdown condition.

l To minimize the wear on moving parts that do not get lubricated when the engine is not running, these SRs have been modified by 'a Note (Note 1 for SR 3.8.1.2 and SR 3.8.1.7) to indicate that all DG starts for these Surveillances may be preceded by an engine prelube period.

For the purposes of this testing, the DGs are started from standby conditions. Standby conditions for a DG mean that the diesel engine coolant and oil are being continuously circulated and temperature is being maintained.

In order to reduce stress and wear on diesel engines, some manufacturers recommend a modified start in which the 1 starting speed of DGs is limited, warmup is limited to this '

i lower speed, and the DGs are gradually accelerated to synchronous speed prior to loading. These start procedures i are the intent of Note 2 of SR 3.8.1.2.

SR 3.8.1.7 requires that, at a 184 day Frequency, the DG starts from standby conditions and achieves required voltage and frequency within 10 seconds.. The minimum voltage and

, frequency stated in the SR are those necessary to ensure the l DG can accept DBA loading while maintaining acceptable.

voltage and frequency levels. Stable operation at the nominal voltage and frequency values is also essential to establishing DG OPERABILITY, but a time constraint is not l-imposed. This is because a typical DG will experience a

. period of voltage and frequency oscillations prior to reaching steady state operation if these oscillations are not dampened by load application. This period may be extended beyond the 10 second acceptance criteria and could be cause for failing the SR. In lieu of a time constraint in the SR, BNP will monitor and trend the actual time to reach steady state operation as a means of ensuring there is i no voltage regulator or governor degradation which could cause a DG to become inoperable. The 10 second start requirement supports and'is conservative with respect to the assumptions in the design basis LOCA ana lysis of UFSAR, Section 6.3 (Ref. 6). The 10 second stayt requirement is ,

i (continued)

Brunswick Unit 2 B 3.8-21 Revision No. 6 l ;

l o.

V.

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.7 (continued)

REQUIREMENTS not applicable to SR 3.8.1.2 (see Note 2 of SR 3.8.1 2),

when a modified start procedure as. described above is used.

If a modified start is not u:;cd, i.he 10 second start requirement of SR 3.8.1.7 applies.

To minimize testing of the DGs, Note 3 to SR 3.8.1.2 and Note 2 to SR 3.8.1.7 allow a single. test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by performing the test on either unit. If the DG fails one of these Surveillances, the DG should be considered inoperable on both units, unless the cause of the failure can be directly related to only one unit.

The 31 day Frequency for SR 3.8.1.2 is consistent with Regulatory Guide 1.9 (Ref. 11). The 184 day Frequency for SR 3.8.1.7 is a reduction in cold testing consistent with Generic Letter 84-15 (Ref.10). These Frequencies provide adequate assurance of DG OPERABILITY, while minimizing degradation resulting from testing.

SR 3.8.1.3 This Surveillance verifies that the DGs are capable of synchronizing and accepting a load approximately equivalent to the continuous rating of the DGs. A minimum run time of 60 minutes is required to stabilize engine temperatures, while minimizing the time that the DG is connected to the offsite source.

Although no power factor requirements are established by this SR, the DG is normally operated at a power factor i between 0.8 lagging and 1.0. The 0.8 value is the design '

rating of the machine, while 1.0 is the generator design limitation which if exceeded could lead to generator instability while in' parallel with the offsite circuit. The l load band is provided to avoid routine overloading of the DG. Routine overloading may result in more frequent teardown inspections in order to maintain DG OPERABILITY.

The 31 day Frequency for this Surveillance is consistent with Regulatory Guide 1.9 (Ref. 11).

(continued) l Brunswick Unit 2 B 3.8-22 Revision No. 6 I i l

l

AC Sources-0perating B 3.8.1 l

, BASES

~

SURVEILLANCE SR 3.8.1.3 (continued)

REQUIREMENTS Note 1 modifies this Surveillance to indicate that diesel engine runs for this Surveillag:e may include gradual loading so that mechanical stress and wear on the diesel engine are minimized.

Note 2. modifies this Surveillance by stating that momentary transients because of changing bus loads do.not invalidate this test. Similarly, momentary power factor transients outside the-range normally used during the performance of this Surveillance do not invalidate the test.

1 Note 3 indicates that this Surveillance should be conducted on only one DG at'a time in order to avoid common cause failures that might result from offsite circuit or grid perturbations.

I Note 4 stipulates a prerequisite requirement for performance l of this SR. A successful DG start must precede this test to l credit satisfactory performance. '

To minimize testing of the DGs, Note 5 allows a single test i

(instead of two tests, one for each_ unit) to satisfy the !

requirements for both units. This is allowed since the main !

purpose of the Surveillance can be met by performing the i test on either unit. If the DG fails one of these Surveillances, the DG should be considered inoperable on both units, unless the cause of the failure can be directly i related to only one unit. I SR 3.8.1.4 This SR provides verification that the level of fuel oil in the engine mounted tank is slightly below the level at which the backup fuel oil transfer pump automatically starts. The level is expressed as an equivalent volume in gallons, and is selected to ensure adequate fuel oil for approximately 30 minutes of DG operation at rated load. This SR may be satisfied by verifying the absence of the associated low level alarm.

The 31 day Frequency is adequate to ensure that a sufficient supply of fuel oil is available, since low level alarms are provided and-facility operators would be aware of any large uses of fuel oil during this period.

(continued)

Brunswick Unit 2 B 3.8-23 Revision No. 6 l

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE' SR' 3.8.1.5 REQUIREMENTS (continued) Microbiological fouling is a major cause of fuel oil degradation. There are numerous bacteria that can grow in fuel oil and cause. fouling, but all must have a water environment in order to survive. Removal of water from the engine mounted tanks once every 31 days eliminates the necessary environment for bacterial survival. This is the most effective means of controlling microbiological fouling.

In addition, it eliminates the potential for water entrainment in the fuel oil during DG operation. Water may come from any of several sources, including condensation, rain water, contaminated fuel oil, and breakdown of the fuel l oil by bacteria. Frequent checking for and removal of j accumulated water minimizes fouling and provides data regarding the watertight integrity of the fuel oil system. ,

The Surveillance Frequencies are established by Regulatory I Guide 1.137 (Ref. 12). This SR is for preventive !

maintenance. The presence of water does not necessarily l represent a failure of this SR provided that accumulated water is removed during performance of this Surveillance.

Removal of accumulated water may be accomplished by draining i a portion of fuel cil from the engine mounted fuel oil tank to the day fuel oil storage tank and draining any accumulated water from the day fuel oil storage tank in accordance with SR 3.8.3.3. The draining evolution will continue until accumulated water is verified to be removed from the engine mounted fuel' oil tank.

SR 3.8.1.6 This Surveillance demonstrates that each required fuel oil transfer pump operates and transfers fuel oil from its associated storage tank to its associated day tank. It is required to support continuous operation of standby power ;

sources. This Surveillance provides assurance that the fuel 1 oil transfer pump is OPERABLE, the fuel oil piping system is !

intact, the fuel delivery piping is not obstructed, and the controls and control systems for fuel transfer systems are OPERABLE.

(continued)

Brunswick' Unit 2' B 3.8-24 Revision No. 6 l

AC Sources-0perating B 3.8.1

' BASES SURVEILLANCE SR '3.8.1.6 (continued)

REQUIREMENTS The Frequency for this SR is consistent with the Frequency for testing the DGs in SR_3.8.1.3. DG operation for SR 3.8.1.3_is normally long enough that fuel oil level in the engine mounted tank will be reduced to the point where the fuel oil transfer pump automatically starts to restore fuel 011~ level in the engine mounted tank.

SR 3.8.1.8 Transfer of each 4.16 kV emergency bus power supply from the normal circuit to the preferred offsite circuit and from the preferred offsite circuit to the alternate offsite circuit demonstrates the OPERABILITY of the offsite circuit distribution network to power the shutdown loads. In lieu of actually initiating an automatic circuit transfer s testing that adequately shows the capability of the transfer is acceptable. The automatic transfer testing may include any series of sequential, overlapping, or total steps so that the entire transfer sequence is verified. The 24 month Frequency of the Surveillance is based on engineering judgment taking into' consideration the' plant conditions .

required to perform the Surveillance, and is intended to be l consistent with expected fuel cycle lengths. Operating !

experience has demonstrated that these components will pass the SR when performed on the 24 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

This SR is modified by three Notes. The reason for 3 Note 1 is that, during operation with the reactor critical, :

performance of SR 3.8.1.8.a, verification of automatic

, transfer capability of the unit power supply from the normal circuit to the preferred offsite circuit, could cause perturbations to the electrical distribution systems that could challenge continued steady state operai,1on and, as a result, plant safety systems. Note 1 is not applicable to '

SR 3.8.1.8.b, verification of manual transfer of the unit power supply from the preferred offsite circuit to the alternate offsite circuit, since this evolution does not cause perturbations of the electrical distribution systems.

Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, both' units' offsite circuits are required to be OPERABLE to (continued)

Brunswick-Unit 2 B 3.8-25 Revision No. 6 1

AC Sources-0perating B 3.8.1 BA3ES SURVEILLANCE SR 3.8.1.8 (continued)

REQUIREMENTS supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the consequences of a potential perturbation to the electrical distribution systems during the performance of this Surveillance, while at the same time avoiding the need for a shutdown of both units to perform this Surveillance, Note 1 only precludes satisfying this Surveillance Requirement for the Unit 2 offsite circuits when Unit 2 is in MODE 1 or 2. During the performance of this Surveillance with Unit 2 not in MODE 1 or 2 and with Unit 1 in MODE 1, 2, or 3; the applicable

' ACTIONS of the Unit 1 and Unit 2 Technical Specifications must be entered if a Unit 2 offsite circuit is rendered inoperable by the performance of this Surveillance. Credit may be taken for unplanned events that satisfy this SR. As stated in Note 2, automatic transfer capability to the SAT is not required to be met when the associated 4.16 kV emergency buses are powered from-the preferred offsite circuit. This is acceptable since the automatic transfer capability function has been satisfied in this condition.

To minimize testing, Note 3 allows. a single test (instead of two tests, one for each unit) to satisfy the requirements for both units.. This is allowed since the main purpose of the Surveillance can be met by performing the test on a single unit. If an offsite circuit fails one of the Surveillances, the offsite circuit should be considered inoperable for both units.

SR 3.8.1.9 Each DG is provided with an engine overspeed trip ta prevent damage to the. engine. Recovery from the transient caused by the loss of a large load could cause diesel engine overspeed, which, if excessive, might result in a trip of the engine. This Surveillance demonstrates the DG capability to reject the largest single load without tripping. The largest single load for each'DG is a core spray-pump (1250 hp). This Surveillance may be accomplished by:

a. -Tripping the DG output breaker with the DG carrying greater than or equal to its associated core spray pump while paralleled to offsite power, or while solely supplying the bus; or (continued)

Brunswick Unit 2 B 3.8-26 Revision No. 6 1

AC Sources-0perating B 3.8.1 BASES SURVEILLANCE SR' 3.8.l'.9 (continued)

REQUIREMENTS

b. Tripping its associated core spray pump with the DG solely supplying the bus.

The load rejection test is acceptable if the increase in-diesel speed does not exceed the overspeed trip setpoint.

The 24 month Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref. 11).

This SR is modified by three Notes. The reason for Note 1 is that, during operation with the reactor critical, performance of this SR could cause perturbations to the electrLal distribution systems that could challenge continued steady state operation and, as a result, plant safety systems. Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, all four DGs are required to be OPERABLE to supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the-consequences of a potential perturbation to the electrical distribution systems.during the performance of this ,

Surveillance, while at the same time avoiding the need to 1 shutdown both units to perform this Surveillance, Note 1 only precludes satisfying this Surveillance Requirement for DG 3 and DG 4 when Unit 2 is in MODE 1, 2, or 3. During the performance of this Surveillance with Unit 2 not in MODE 1, 2, or 3 and with Unit.1 in MODE 1, 2,- or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications !

must be entered if DG 3 or DG 4 is rendered inoperable by I the performance of this Surveillance. Credit may be taken for unplanned events that satisfy this SR. In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, Note 2 i requires that, if synchronized to offsite power, testing must be performed using a power factor s 0.9. This power factor is chosen to be representative of the actual design basis inductive loading that the DG would experience. To l minimize testing of the DGs, Note 3 allows a single test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by performing the test on either unit. If the DG fails one of these

' Surveillances, the DG should be considered inoperable on both units, unless the cause of the failure can be directly :

related to only one unit..

(continued)

Brunswick Unit 2 B 3.8-27 Revision No. 6 1

AC Sources-Operating B 3.8.1 BASES

- SURVEILLANCE .SR' 3.8.1.10

. REQUIREMENTS (continued) Consistent with Regulatory Guide 1.9 (Ref. 11),. paragraph C.2.2.12, this Surveillance demonstrates that DG !

non-critical protective functions (e.g., high jacket water temperature) are bypassed on an-ECCS initiation test signal and critical protective functions (engine overspeed, generator differential overcurrent, low lubricating oil pressure, reverse power, loss of field, and phase overcurrent-voltage restrained) trip the DG to avert substantial damage to the DG unit. The non-critical trips are bypassed during DBAs and provide an alarm on an abnormal engine. condition. This alarm provides the operator with sufficient time to react appropriately. The DG availability to mitigate the DBA is more critical than protecting the engine against minor problems that are not immediately detrimental to emergency operation of the DG.

The 24 month Frequency is based on engineering judgment, takes into consideration plant conditions required to perform the Surveillance, and is intended to be consistent ,

with expected fuel cycle lengths. Operating experience has i demonstrated that these components will pass the SR when l performed at the 24 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

The SR is modified by a Note. To minimize testing of.the DGs, the Note allows a single test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the ,

Surveillance can be met by performing the. test on either j unit. If the DG fails one of these Surveillances, the DG i should be considered inoperable on both units, unless the cause of the failure can be directly related to only one unit.

SR 3.8.1.11 Brunswick Nuclear Plant performs a 60 minute run greater ,

than or equal to the continuous rating (3500 kW) which !

bounds the maximum expected post-accident DG loading. The l

'DG starts-for this Surveillance can be performed either from .

(continuedl l J Brunswick Unit 2' B 3.8-28 Revision No. 6 I i

i AC Sources-0perating B 3.8.1 BASES

' SURVEILLANCE- SR 3.8.1.11 (continued) l REQUIREMENTS standby or hot conditions. The provisions for prelube and' warmup, discussed in the Bases for SR 3.8.1.2, and for !

gradual loading, discussed in the Bases for SR 3.8.1.3, are i applicable to this SR.

In order to ensure that the DG is tested under load I conditions that are,as close to design conditions as possible, testing must be performed using a power factor s 0.9. This power factor is chosen to be representative of.

the actual design basis inductive loading that the DG could !'

experience. A load band is provided to avoid routine overloading of the DG, Routine overloading may result in more frequent teardown inspections in order to maintain DG OPERABILITY.

The 24 month Frequency is consistent with the recommendations of Regulatory Guide 1.9 (Ref. 11), Table 1; i takes into consideration plant conditions required to i perform the Surveillance; and is intended to be consistent I with expected fuel cycle lengths. l This Surveillance has been modified by two Notes. Note 1 ;

states that momentary transients due to changing bus loads do not invalidate this test. Similarly, momentary power factor transients above the limit do not invalidate the !

test. To minimize testing of the DGs, Note 2 allows a l single test-(instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the Surveillance can be met by performing the test on either unit. If the DG fails one of these Surveillances, the DG should be considered inoperable en both units, unless the cause of the failure can be directly related to only one unit.

SR 3.8.1.12 Consistent with Regulatory Guide 1.9 (Ref. 11), paragraph C.2.2.13, demonstration of the test mode override feature ensures that the DG availability under accident conditions is not compromised as-the result of testing. Interlocks to the LOCA sensing circuits cause the DG to' automatically reset to ready-to-load operation if an ECCS initiation (continued)

Brunswick' Unit.2 B 3.8-29 Revision No. 6 i

, , AC Sources-0perating j B 3.8.1 BASES

4 SURVEILLANCE -SR 3.8.1.12 (continued)-

REQUIREMENTS' signal is received during operation in the test mode.

Ready-to-load operation.is. defined as the DG running at rated speed and voltage with the DG output breaker open.

-These provisions for automatic switchover are required by

~

IEEE-308 (Ref, 13), paragraph 6.2.4(6).

, In lieu of actually returning the DG to ready-to-load status, testing that adequately shows the capability of the DG to perform'this function is acceptable. This testing may include any series of sequential, overlapping, or total steps so that the entire sequence is verified.

The 24 month Frequency is consistent with the

-- recommendations of Regulatory Guide 1.9 (Ref.11), Table 1;

, takes into consideration plant conditions required to perform the Surveillance; and is intended to be consistent with expected fuel cycle lengths.

This SR is modified by a Note. To minimize testing of the DGs, the Note allows a single test (instead of two tests, one for each unit) to satisfy the requirements for.both j units. This is allowed since.the main purpose of the i

Surveillance can be met by performing'the test on either unit. If the DG fails one of these Surveillances, the DG should be considered inoperable on both" units, unless the l cause 'of the failure can be directly related to' only one L

unit.

l SR 3.8.1.13 l Under accident conditions loads are sequentially connected i to the bus by the automatic load sequence time delay. relays.

I The sequencing logic controls the permissive and starting l signals to motor breakers to prevent overloading of the DGs

! due to high motor starting currents._ The 10% load sequence time interval tolerance ensures that sufficient time exists

for the DG to restore frequency and voltage prior to l applying the next load and that safety analysis assumptions L regarding ESF equipment time delays are not violated.

I Reference 4 provides a summary of the au.tomatic loading of ESF buses.

(continuedl Brunswic'k Unit 2 B 3.8-30 Revision No. 6 I w

AC Sources-0perating B 3.8.1

, BASES p

l SURVEILLANCE 'SR 3.8.1.13 (continued)

REQUIREMENTS The Frequency of 24 months is consistent with the recommendations of Regulatory Guide 1.9 (Ref.11), Table 1; takes into consideration plant conditions required to perform the Surveillance; and is intended to be consistent with expected fuel cycle lengths.

This SR is modified by a Note. The reason for the Note is I that performing the Surveillance would remove a required I offsite circuit from service, perturb the electrical distribution system, and challenge safety systems. Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, all l four DGs, and associated load sequence relays, are required to be OPERABLE to supply power to these systems when either

'one or both units are in MODE 1, 2, or 3. In order to reduce potential consequences associated with removing a required offsite circuit from service during the performance of this Surveillance, reduce consequences of a potential perturbation to the electrical distribution systems during

. the performance of this Surveillance, and reduce challenges to safety systems, while at the same time avoiding the need l to shutdown both units to perform this Surveillance, the Note only precludes satisfying this Surveillance Requirement for the load sequence relays associated with DG 3 and DG 4 i when Unit 2 is in MODE 1, 2, or~3. During the performance

! of this Surveillance with Unit 2 not in MODE 1, 2, or 3 and with Unit 1 in MODE 1, 2, or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications must be entered if a required offsite circuit, DG 3, or DG 4 is rendered inoperable by the performance of this Surveillance.

Credit may be taken'for unplanned events that satisfy this SR.

SR 3.8.1.14 In the event of a DBA coincident with a loss of offsite power, the DGs are required to supply the necessary power to ESF systems so that the fuel, RCS, and containment design limits are not exceeded.

This Surveillance demonstrates DG operation during a loss of offsite power actuation test signal in conjunction 9:ith an l ECCS initiation signal. This test verifies all actions encountered from the event, including shedding of the (continued)

L Brunswick Unit 2- B 3.8-31 Revision No. 6 l l 1 L

AC Sources-0perating B 3.8.1 i

BASES SURVEllLANCE SR 3.8.1.14 (continued)

REQUIRtMENTS nonessential loads and energization of the emergency buses and respective loads from the DG. It further demonstrates the capability of the DG to automatically achieve the required voltage and frequency within the specified time.

The 10.5 second time period, which is allowed for the DG to auto-start and connect to its respective emergency bus, is conservatively derived from requirements of the accident analysis for responding to a design basis large break LOCA.

The Surveillance should be continued for a minimum of 5 minutes in order to demonstrate that all starting transients have decayed and stability has been achieved.

The requirement to verify the connection and power supply of permanent and auto-connected loads is intended to satisfactorily show the relationship of these loads to the '

DG loading logic. In certain circumstances, many of these loads cannot actually be connected or loaded without undue hardship or potential for undesired operation. For instance, Emergency Core Cooling Systems (ECCS) injection ;

valves are not desired to be stroked open, or systems are i not capable of being operated at full flow, or RHR systems performing a decay heat removal function are not desired to !

be realigned to the ECCS mode of operation.

In lieu of actual demonstration of connection and loading of loads, testing that adequately shows the capability of the DG system to perform these functions is acceptable. This testing may include any series of sequential, overlapping, or total steps so that the entire connection and loading ;

sequence is verified.

The Frequency of 24 months takes into consideration plant conditions required to perform the Surveillance and is intended to be consistent with an expected fuel cycle length.

This SR is modified by two flotes. The reason for flote 1 is to minimize wear and tear on the DGs during testing. For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil being continuously circulated and temperature maintained consistent with procedural guidance. The reason for Note 2 is that performing the Surveillance would remove a required offsite circuit from service, perturb the electrical (continued)

Brunswick Unit 2 B 3.8-32 Revision No. 6 1

7-

!1 AC Sources-Operating B.3.8.1 BASES l i

l i

SURVEILLANCE SR 3.8.1.14 (continued)

REQUIREMENTS distribution system, and challenge safety systems. Due to the shared configuration of certain systems (required to mitigate DBAs and transients) between BNP Units 1 and 2, all four DGs are required to be OPERABLE to supply power to these systems when either one or both units are in MODE 1, 2, or 3. In order to reduce the potential consequences associated with removing a required offsite circuit from ,

service during the performance of this. Surveillance, reduce i consequences of a potential perturbation to the electrical distribution systems during the performance of this Surveillance, and reduce challenges to safety systems, while at the same time avoiding the need to shutdown both units to perform this Surveillance, Note 2 only precludes satisfying this Surveillance Requirement for DG 3 and DG 4 when Unit 2 is in MODE 1, 2, or 3. During the performance of this Surveillance with Unit 2 not in MODE 1, 2, or 3 and with Unit 1 in MODE 1, 2, or 3; the applicable ACTIONS of the i Unit I and Unit 2 Technical Specifications must be entered ,

if a required offsite circuit, DG 3, DG 4, or other l supported Technical Specification equipment is rendered inoperable by the performance of this Surveillance. Credit 4 may be taken for unplanned events that satisfy this SR. l I

REFERENCES 1. UFSAR, Section 8.3.1.2.

2. UFSAR, Sections 8.2 and 8.3. ,

l

3. NRC Diagnostic Evaluation Team Report for Brunswick Steam Electric Plant dated August 2, 1989, from J.M. Taylor (NRC) to S.H. Smith, Jr. (CP&L).

4. UFSAR, Table 8.3.1-6.

5. Safety Guide 9.

6. UFSAR, Chapter 6.

7. UFSAR, Chapter 15.

8. 10 CFR 50.36(c)(2)(ii).

9. Regulatory Guide 1.93, December 1974.

10. Generic Letter 84-15.

(continued)

Brunswick Unit 2' B 3.8-33 Revision No. 6 i

AC Sources-0perating B 3.8.1 i

BASES l

REFERENCES 11. Regulatory Guide 1.9, July 1993, Revision 3.

(continued)

12. Regulatory Guide 1.137, January 1978.

13. IEEE Standard 308.

Brunswick Unit 2 B 3.8-34 Revision No. 6 l

[t L

AC Sources-Shutdown ;

B 3.8.2 B-3.8 ELECTRICAL POWER SYSTEMS i

B.3.8.2.- AC Sources-Shutdown BASES-j BACKGROUND A description of the AC sources is provided in the Bases for j LCO 3.8.1, "AC Sources-0perating. " '

l APPLICABLE The OPERABILITY of the minimum AC sources during MODES 4 SAFETY ANALYSES and 5, and-during movement of irradiated fuel assemblies in the secondary containment ensures that: ,

a. The facility can be maintained in the shutdown or i refueling condition for extended periods; l

b. Sufficient instrumentation and control capability is available for monitoring and maintaining the unit status; and c.- Adequate AC electrical power is provided to mitigate events postulated during shutdown, such as an !

inadvertent draindown of the vessel or a fuel handling accident.

. In general, when the unit is shutdown the Technical 4 Specifications-requirements ensure that the unit has the !

capability to mitigate the consequences of postulated j accidents. However, assuming a single failure and ;

concurrent loss of all offsite power is not required. The rationale for this is based on the fact that many Design Basis Accidents (DBAs) that are analyzed in MODES 1, 2, I and 3 have no specific analyses in MODES 4 and 5. Worst 1 case bounding events are deemed not credible in MODES 4 and 5 because the energy contained within the reactor ,

pressure boundary, reactor coolant temperature and pressure, "

and corresponding stresses result in the probabilities of occurrences significantly reduced or eliminated, and minimal consequences. These deviations from DBA analysis assumptions and design requirements during shutdown conditions are allowed by the LCO for required systems.

During MODES 1, 2, and 3, various deviations from the i analysis assumptions and design requirements are allowed within the ACTIONS. This allowance is in recognition that certain testing and maintenance activities must be (continued) ;

Brunswick Unit 2 B 3,8-35 Revision No. 6 l

AC Sources-Shutdown B 3.8.2 BASES APPLICABLE conducted, provided an acceptat'e S ci of risk is not SAFETY ANALYSES exceeded. During MODES 4 and 5, performance of a (continued) significant number of required testing and maintenance activities is also required. In MODES 4 and 5, the activities are generally planned and administratively l controlled. Relaxations from typical MODES 1, 2, and 3 LC0 requirements are acceptable during shutdown MODES, based on:

a. The fact that time in an outage is limited. This is a !

risk prudent goal as well as a utility economic consideration.

b. Requiring appropriate compensatory measures for certain conditions. These may include administrative controls, reliance on systems that do not necessarily meet typical design requirements applied to systems credited in operation MODE analyses, or both,

c. Prudent utility consideration of the risk associated with multiple activities that could affect multiple systems.

d. Maintaining, to the extent practical, the ability to perform required functions (even if not meeting MODES 1, 2, and 3 OPERABILITY requirements) with systems assumed to function during an event.

In the event of an accident during shutdown, this LCO ensures the capability of supporting systems ner.essary for avoiding immediate difficulty, assuming a loss of all offsite power.

The AC sources satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii)

(Ref. 1).

LC0 One Unit 2 offsite circuit capable of supplying the onsite Class lE power distribution subsystem (s) of LCO 3.8.8,

" Distribution Systems-Shutdown," ensures that all required Unit 2 loads are powered from offsite power. Two OPERABLE DGs, associated with distribution subsystem (s) required OPERABLE by LCO 3.8.8, ensures that a diverse power source is available for providing electrical power support assuming a loss of the offsite circuit (s). In addition, some Unit 1 equipment may be required by Unit 2 (e.g., Control Room Emergency Ventilation (CREV) System components). Therefore, one Unit 1 qualified circuit between the offsite (continued)

Brunswick Unit 2 B 3.8-36 Revision No. 6 1

AC Sources-Shutdown B 3.8.2 BASES LC0 transmission network and the onsite Class lE AC electrical (continued) power distribution subsystem (s), needed to support the Unit 1 equipment required to be OPERABLE, must also be OPERABLE. Together, OPERABILITY of the required offsite circuit (s) and DGs ensures the availability of sufficient AC sources to operate the plant in a safe manner and to ;

mitigate the consequences of postulated events during '

shutdown (e.g., fuel handling accidents and reactor vessel draindown). ;

The qualified offsite circuit (s) must be capable of maintaining rated frequency and voltage while connected to the respective emergency bus (es), and of accepting required loads during an accident, Qualified offsite circuits are those that are described in the UFSAR and are part of the licensing basis for the unit. The Unit 2 qualified offsite circuit consists of the incoming breaker and disconnect to and including the associated startup auxiliary transformer (SAT) or unit auxiliary transformer (UAT), the respective circuit path to and including the balance of plant bus (es), j and the circuit path to associated 4.16 kV emergency bus (es) i required by LC0 3.8.8. The Unit I qualified offsite circuit consists of the incoming breaker and disconnect to and including the associated SAT or UAT, the respective circuit path to and including the balance of plant bus (es), and the circuit path to associated 4.16 kV emergency bus (es) required by LCO 3.7.3, LC0 3.7.4, and LC0 3.8.5.

The required DGs must be capable of starting, accelerating to minimum acceptable frequency and voltage, and connecting to its respective 4.16 kV emergency bus on detection of bus undervoltage. This sequence must be accomplished within 10.5 seconds. Each required DG is required to have an OPERABLE air start system consisting of one air header, one receiver, associated air compressor, piping, valves, and instrument controls to ensure adequate starting and control air capacity. Additionally, each DG must be capable of accepting required loads within the assumed loading sequence intervals, and must continue to operate until offsite power can be restored to the 4.16 kV emergency buses. These capabilities are required to be met from a variety of initial conditions such as DG in standby with engine at ambient conditions. Additional DG capabilities must be demonstrated to meet required Surveillances, e.g.,

capability of the DG to revert to standby status on an ECCS signal while operating in parallel test mode. Proper (continued)

Brunswick Unit 2 B 3.8-37 Revision No. 6 l

AC Sources-Shutdown B 3.8.2 BASES LC0 sequencing of loads, including tripping of nonessential (continued) loads, is required function for DG OPERABILITY. The necessary portions of the Nuclear Service Water System are also required to provide appropriate cooling to each required DG.

It is acceptable for 4.16 kV emergency buses to be cross tied during shutdown conditions, permitting a single offsite power circuit to supply all required buses provided both units are shutdown.

APPLICABILITY The AC sources are required to be OPERABLE in MODES 4 and 5 and during movement of irradiated fuel assemblies in the secondary containt 't to provide assurance that:

a. Systems providing adequate coolant inventory makeup are available for the irradiated fuel assemblies in the core in case of an inadvertent draindown of the reactor vessel;

b. Systems needed to mitigate a fuel handling accident are available;

c. Systems necessary to mitigate the effects of events that can lead to core damage during shutdown are 3 available; and

d. Instrumentation and control capability is available l for monitoring and maintaining the unit in a cold '

shutdown condition or refueling condition.

AC power requirements for MODES 1, 2, and 3 are covered in LC0 3.8.1.

ACTIONS LC0 3.0.3 is not applicable while in MODE 4 or 5. However, since irradiated fuel assembly movement can occur in Mode 1, 2, or 3, the ACTIONS have been modified by a Note stating that LCO 3.0.3 is not applicable. If moving irradiated fuel assemblies while in MODE 4 or 5, LCO 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, or 3, the fuel movement is independent of reactor operations. Entering LCO 3 0.3, while in MODE 1, 2, or 3, would require the unit to be shutdown, but would not require immediate suspension of movement of irradiated fuel assemblies. The Note to the ACTIONS, "LCO 3.0.3 is not (continued)

Brunswick Unit 2 B 3.8-38 Revision No. 6 I m

AC Sources-Shutdown B 3.8.2 l

BASES ACTIONS applicable," ensures that the actions for immediate (continued) suspension of irradiated fuel assembly movement are not postponed due to entry into LC0 3.0.3.

A.1 and B.1 With one or more required offsite circuits inoperable, or with one DG inoperable, the remaining required AC sources may be capable of supporting sufficient required features (e.g., system, subsystem, division, component, or device) to allow continuation of CORE ALTERATIONS, fuel movement, and operations with a potential for draining the reactor vessel.

For example, if two 4.16 kV emergency buses are required per LC0 3.8.8, one emergency bus with offsite power available may be capable of supplying sufficient required features.

By the allowance of the option to declare required features inoperable that are not powered from offsite power (Required Action A.1) or capable of being powered by the required DG (Required Action B.1), appropriate restrictions can be implemented in accordance with the affected required feature (s) LCOs' ACTIONS. Required features remaining powered from the qualified offsite power circuit, even if the circuit is inoperable to other required features, are not declared inoperable by this Required Action.

A.2.1 A.2.2 A.2.3, A.2.4, B.2.1, 8.2.2, B.2.3, B.2.4, C.1, C.2, C.3, and C.4 I i

With an offsite circuit not available to all required ;

4.16 kV emergency buses or one required DG inoperable, the I option still exists to declare all required features inoperable (per Required Actions A.1 and B.1). Since this option may involve undesired administrative efforts, the allowance for sufficiently conservative actions is made.

With two required DGs inoperable, the minimum required <

diversity of AC power sources is not available, it is, l therefore, required to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies in the secondary containment, and :

activities that could result in inadvertent draining of the reactor vessel.

Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition.

These actions minimize the probability of the occurrence of postulated events, it is further required to immediately (continued)

Brunswick Unit 2 B 3.8-39 Revision No. 6 1

AC Sources-Shutdown B 3.8.2 BASES ACTIONS A.2.1 A.2.2. A.2.3, A.2.4 B.2.1, 8.2.2, B.2.3, B.2.4, C.1, C.2, C.3, and C.4 (continued) initiate action to restore the required AC sources and to j continue this action until restoration is accomplished in i order to provide the necessary AC power to the plant safety I systems.

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. The restoration of the required AC electrical power sources should be completed as quickly as possible in order to minimize the time during which the plant safety systems may be without sufficient power.

Pursuant to LC0 3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it are inoperable, resulting in de-energization. Therefore, the Required Actions of Condition A have been modified by a Note to indicate that when Condition A is entered with no AC power to any required 4.16 kV emergency bus, ACTIONS for LCO 3.8.8 must be immediately entered. This Note allows Condition A to provide requirements for the loss of the offsite circuit i

whether or not a required bus is de-energized. LC0 3.8.8 i provides the appropriate restrictions for the situation l involving a de-energized bus.

I SURVEILLANCE SR 3.8.2.1 REQUIREMENTS SR 3.8.2.1 requires the SRs from LC0 3.8.1 that are necessary for ensuring the OPERABILITY of the required AC sources in other than MODES 1, 2, and 3 to be met. SR 3.8.1.8 is not required to be met since only one offsite circuit is required to be OPERABLE. SR 3.8.1.12 is not required to be met because the required OPERABLE DG(s) is not required to undergo periods of being synchronized to the offsite circuit. Refer to the corresponding Bases for LC0 3.8.1 for a discussion of each SR.

This SR is modified by a Note. The reason for the Note is to preclude requiring the OPERABLE DG(s) from being paralleled with the offsite power network or otherwise rendered inoperable during the performance of SRs, and to preclude de-energizing a required 4.16 kV emergency bus or (continued)

Brunswick Unit 2 B 3.8-40 Revision No. 6 1

p; i AC Sources-Shutdown B 3.8.2 BASES.

SURVEILLANCE SR 3.8.2.1 (continued)

l. REQUIREMENTS 1: disconnecting'a' required offsite circuit during~ performance !

of SRs. With limited AC sources available, a single event j could compromise both the required circuit (s) and the DGs. '

It is the intent that these SRs must still be capable of being met, but actual performance is not required during periods when the DGs and offsite circuit (s) are required to be OPERABLE unless Unit 1 Specification 3.8.1, "AC Sources-0perating," requires performance of these SRs.

I When Unit 1 Specification 3.8.1 requires performance of '

' these SRs, AC sources availability is not limited due to-the l Unit I requirements for AC source OPERABILITY. Therefore, a single event, in this condition, is not expected to compromise both the required offsite circuit (s) and the DG(s).

1 REFERENCES 1. 10 CFR 50.36(c)(2)(ii).

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1 L ;

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Brunswick Unit 2 .8 3.8-41 Revision No. 6 l I

m Diesel Fuel Oil B 3.8.3 8 3.8 ELECTRICAL POWER SYSTEMS B 3.8.3 Diesel Fuel Oil BASES BACKGROUND Each diesel generator (DG).is provided with storage tanks having a fuel. oil capacity: sufficient to operate that DG for a period of approximately 7 days while the DG is operating at' rated load as-discussed in UFSAR, Section 8.3.1.1.6.2.8 (Ref. 1). The fuel consumption rate is calculated using the assumption. that four DGs are available. The diesel

~ generator fuel oil capacity in.the combination of the fuel oil volumes of the Seismic Class I day fuel oil storage tanks (one tank for each diesel generator) and the Seismic Class I engine mounted fuel' tanks (one tank attached to each

. diesel generator) provide approximately four days of diesel generator. operation at rated load. The main fuel oil storage tank provides approximately three additional days of

' diesel generator operation at rated load to each of the day

-fuel oil storage. tanks. The main fuel oil storage tank is seismically designed but not seismically qualified.

Following the postulated loss of the main fuel oil storage.

tank, the onsite fuel oil capacity in seismically qualified storage tanks is sufficient to operate the DGs for longer than the time.to replenish the onsite supply from outside sources as discussed in Refere'nce 1.

Fuel oil is transferred from the day fuel oil storage. tank to the engine mounted fuel-tank by either of.two transfer

~

pumps associated with each day feel oil storage tank. Fuel oil-is gravity fed from the main fuel oil storage tank to the day fuel oil storage tanks through manual or automatic vaives. However, level in the day fuel oil storage tanks is currently maintained through the use of.the manual valves.

Redundancy of pumps and' piping, and the normally isolated gravity feed lines from the main fuel oil storage tank to the day fuel oil storage tanks, precludes the failure of one pump, or'the rupture.of any pipe, valve, or. tank to result in the loss of more than one DG. All outside tanks, pumps, and piping (other than the main fuel oil storage tank and a portion of the associated. piping) are located underground.

(continued)

Brunswick-Unit'2 B 3.8-42 Revision No. 6 l

Diesel Fuel Oil B 3.8.3 BASES BACKGROUND For proper operation of the standby DGs, it is necessary to (continued) ensure the proper quality of the fuel oil. Regulatory p Guide 1.137 (Ref. 2) addresses the recommended fuel oil practices as modified by Reference 3. The fuel oil properties governed by SRs of this Specification are the l

water content, the kinematic viscosity, and impurity level.

1 APPLICABLE The initial conditions of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in VFSAR, Chapter 6 (Ref. 4), and Chapter 15 (Ref. 5), assume Engineered Safety Feature (ESF).

l systems are OPERABLE. The DGs are designed to provide i sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems

so that reactor fuel, Reactor Coolant System, and l

containment design limits are not exceeded. These limits l are discussed in more detail in the Bases for Section 3.2, I- " Power Distribution Limits"; Section 3.5, " Emergency Core l Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC) System"; and Section 3.6, " Containment Systems."

Since diesel fuel oil supports the operation of the standby AC power' sources, it satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii) (Ref. 6).

LC0 Stored diesel fuel oil is required to have sufficient supply for approximately 7 days of operation at rated load. It is also required to meet specific standards for quality. These requirements, in conjunction with an ability to obtain replacement supplies within approximately 7 days, support i the availability of DGs required to shut down the reactor and to maintain it in a safe condition for an anticipated operational occurrence (A00) or a postulated DBA with loss ,

of offsite power. DG engine mounted tank fuel oil requirements, as well as transfer capability from the day l

fuel oil storage tank to the engine mounted tank, are addressed in LC0 3.8.1, "AC Sources-0perating," and LC0 3.8.2, "AC Sources-Shutdown."

l (continued) l l

1 1

Brunswick Unit 2 B 3.8-43 Revision No. 6 l l

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Diesel Fuel Oil B 3.8.3 BASES (continued)

APPLICABILITY The AC sources (LCO 3.8.1 and LCO 3.8.2) are required to ensure the availability of the required power to shut down the reactor and maintain it in a safe shutdown condition after an A00 or a postulated DBA. Because stored diesel fuel oil supports LC0 3.8.1 and LCO 3.8.2, stored diesel fuel oil, is required to be within limits when the associated DG is required to be OPERABLE.

ACTIONS The ACTIONS Table is modified by a Note indicating that separate Condition entry is allowed for each DG. This is ,

acceptable, since the Required Actions for each Condition provide appropriate compensatory actions for' each inoperable DG subsystem. Complying with the Required Actions for one l inoperable DG subsystem may allow for continued operation, and subsequent inoperable DG subsystem (s) governed by separate Condition entry and application of associated Required Actions.

A.1 and 8.1 With one or more required DGs with fuel oil level in the associated day fuel oil storage tanks < 22,650 gallons per required DG and a 17,000 gallons per required DG and the fuel oil level in the main fuel oil storage tank 2 20,850 gallons per required DG, the approximate 7 day fuel oil supply for a required DG is not available. However,-

Condition A is restricted to fuel oil level reductions that maintain at least an approximate 6 day supply (at least an approximate 3 day supply is available in the required day fuel oil storage tanks and an approximate 3 day supply is available in the main fuel oil storage tank).

With one or more required DGs with fuel oil level in the main fuel oil storage tank < 20,850 gallons per required DG and a 13,900 gallons per required DG and the fuel oil level in the required day fuel oil storage tank (s) 2 22,650 gallons per required DG, the approximate 7 day fuel oil supply for a required DG is not available. However, Condition B is restricted to fuel oil level reductions that-maintain at least an approximate 6 day supply (at least an approximate 2 day supply is available in the main fuel oil storage tank and an approximate 4 day supply is available in the required day fuel oil storage tanks (s)).

(continued)

Brunswick Unit 2 B 3-.8-44 Revision No. 6 l

Diesel fuel Oil B 3.8.3 BASES ACTIONS. A.1 and B.1 (continued)

These circumstances may be caused by events such as:

a. Full load operation required for an inadvertent start while. at minimum required level; or

b. Feed and bleed operations that may be necessitated by increasing particulate levels or any number of other oil quality degradations.

These restrictions (Required Actions A.1 and B.1) allow sufficient time for obtaining the requisite replacement volume and performing the analyses required prior to addition of the fuel oil to the tank. A period of 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months is considered sufficient to complete restoration of the required level prior.to declaring the DG inoperable. This period is acceptable based on the remaining capacity (2: approximately 6 days), the fact that procedures will be initiated to obtain replenishment, and the low probability of an event during this brief period.

C.1 This Condition is entered as a result of a failure to meet the acceptance criterion for particulates. Normally, trending of particulate levels allows sufficient time to correct high particulate levels prior to reaching the limit of acceptability. Poor sample procedures (bottom sampling),

contaminated sampling equipment, and errors in laboratory analysis can produce failures that do not follow a trend.

Since the presence of particulates does not mean failure of the fuel oil to burn properly in the diesel engine, since particulate concentration is unlikely to change significantly between Surveillance Frequency intervals, and since proper engine performance has been recently demonstrated (within 31 days), it is prudent to allow a brief period prior to declaring the associated DG inoperable. The 7 day Completion Time allows for further evaluation, resampling, and re analysis of the DG fuel oil.

(continued) l l

l Brunswick Unit 2 B 3.8-45 Revision No. 6 l 1

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p Diesel Fuel Oil B 3.8.3 BASES l

)

i t

ACTIONS Qd 1 (continued) _

l With a Required Action and associated Completion Time of Condition A, B, or C not met, or the stored diesel fuel oil ,

not.within limits for reasons other than-addressed by j

. Conditions . A, B, or C, the associated DG may be incapable of performing its intended function and must be immediately declared. inoperable.

l SURVEILLANCE. SR 3.8.3.1

~ REQUIREMENTS This SR provides verification that there is an adequate inventory of fuel oil in the storage tanks to support each l DG's operation for approximately 7 days at rated load. The l approximate 7 day period is sufficient time to place the unit in'a safe shutdown condition and to bring in replenishment fuel from an offsite location. For the purposes of this SR,.the verification of the main fuel oil storage tank fuel oil volume is performed on a per DG basis.

This per DG volume is obtained using the following equation:

VOL~ VOL VOL N go _

where

!. M yot = measured fuel oil volume of the main fuel oil storage tank, l

U yot = unusable fuel oil volume of the main !

fuel oil storage tank, and N

oc

= number of DGs required to be OPERABLE.

.The results from this equation must be 2: 20,850 gallons in order to satisfy the acceptance criteria of SR 3.8.3.1.b.

The 31 day Frequency is adequate to ensure that a sufficient supply of fuel' oil is available, since low level alarms are provided and unit operators would be aware' of any large uses of fuel oil during this period.

(continued)

Brunswick Unit 2 .B 3.8-46 Revision No. 6 1

Diesel Fuel Oil B 3.8.3 BASES SURVEILLANCE SR 3.8.3.2 REQUIREMENTS Once por 92 days, the stored fuel oil is sampled in accordance with ASTM D4057-88, (Ref. 7) and analyzed to establish that the viscosity limits specified in Table 1 of ASTM D975-88 (Ref. 7) are met for stored fuel oil . The 92 day period is acceptable because fuel oil viscosity, even if it was not within stated limits, would not have an immediate effect on DG operation. This Surveillance, in combination with the fuel oil delivery certificate of compliance, ensures the availability of high quality fuel oil for the DGs.

Fuel oil degradation during long term storage shows up as an increase in particulate, mostly due to oxidation. The presence of particulate does not mean that the fuel oil will not burn properly in a diesel engine. The particulate can cause fouling of filters and fuel oil injection equipment, however, which can cause engine failure.

Particulate concentrations should be determined in accordance with ASTM D2276-89 (Ref. 7), Method A3. This method involves a gravimetric determination of total particulate. concentration in the fuel oil and has a limit of 10 mg/1. It is acceptable to obtain a field sample for subsequent labor atory testing in lieu of field testing. For the BNP design, the total volume of stored fuel oil is contained in more than two interconnected tanks. Therefore, each tank must be considered and tested separately.

The Frequency of this test takes into consideration fuel oil degradation trends-that indicate that particulate concentration is unlikely to change significantly between Frequency intervals.

The acceptability of new diesel fuel oil is verified by the use of a certificate of compliance provided by the diesel fuel oil supplier for each new fuel oil delivery. The certificate of compliance includes certification of each of the ASTM 2-D fuel oil properties included in Table 1 of ASTM D975-88 (Ref. 7) and API gravity are within required limits.

Therefore, the acceptability of new fuel oil for use prior to. addition to the storage tanks is determined by verifying that the new fuel oil has not become contaminated with other products during transit, thus altering the quality of the (continued)

Brunswick Unit 2 B 3.8-47 Revision No. 6 I l

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Diesel Fuel Oil B 3.8.3 BASES SURVEILLANCE SR 3.8.3.2 (continued)

REQUIREMENTS fuel oil. This ensures new fuel oil quality is maintained consistent with that identified in the certificate of compliance. Once the verification is satisfactorily completed, the fuel oil may be added to the storage tanks without concern for contaminating the entire volume of fuel oil in the storage tanks. I Failure to determine the acceptability of the new diesel fuel oil is cause for rejecting the new fuel oil, but does l not represent a failure to meet the LC0 since the fuel oil !

is not added to the storage tanks.

SR 3.8.3.3 ;

i Microbiological fouling is a major cause of fuel oil i degradation. There are numerous bacteria that can grow in '

fuel oil and cause fouling, but all must have a water environment in order to survive. Removal of water from the fuel storage tanks once every 31 days eliminates the ;

necessary environment for bacterial survival. This is the most effective means of controlling microbiological fouling. ;

In addition, it eliminates the potential for water 1 entrainment in the fuel oil during DG operation. Water may come from any of several sources, including condensation, ground water, rain water, contaminated fuel oil, and from breakdown of the fuel oil by bacteria. Frequent checking for and removal of accumulated water mininiizes fouling and provides data regarding tne watertight integ.-ity of the fuel oil system. The Surveillance Frequency is esr.ablished by Regulatory Guide 1.137 (Ref. 2). This SR is for preventive maintenance. The presence of water does not nacessarily represent failure of this SR, provided the accumulated water is removed during performance of the Surveillance.

REFERENCES 1. UFSAR, Sec t i on 8. :. . l .1. 6. 2. 8.

2. Regulatory Guide 1.137, January 1978.

3. UFSAR, Section 1.8.

4. UFSAR, Chapter 6.

(continued)

Brunswick Unit 2 B 3.8-48 Revision No. 6 1

l Diesel Fuel Oil B 3.8.3 BASES REFERENCES 5. UFSAR, Chapter 15.

(continued)

6. 10 CFR 50.36(c)(2)(ii).

7. ASTM Standards: D4057-88; D975-88; and D2276-89.

l Brunswick Unit 2 B 3.8-49 Revision No. 6 I

i DC Sources-0perating B 3.8.4 B 3.8 ELECTRICAL-POWER SYSTEMS B 3.8.4 DC Sources-0perating BASES BACKGROUND The DC electrical power system provides the AC. emergency

power. system with control power. It also provides both-motive and control power to selected safety related equipment. -Also, these DC subsystems provide a source of uninterruptible power to AC vital buses. As required by design bases in UFSAR Section 8.3.2.1.1 (Ref. 1), the DC electrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a single failure. The DC electrical power system also ' conforms to the recommendations of Safety Guide 6 (Ref. 2).

The DC power sources provide,both motive and control power to selected safety related equipment, as well as power for circuit breaker control, relay operation, plant annunciation, and emergency lighting. There are two independent divisions per unit, designated Division I and Division II. Each division consists of a 250 VDC battery center tapped to form two 125 VDC batteries. Each 125 VDC battery has an associated full capacity battery charger.

The chargers are supplied from the same AC load groups for which the associated DC. subsystem supplies the control power.

During normal-~ operation, the DC loads are powered from the battery chargers with the batteries floating on the system. !

In case of loss of normal power to the battery charger, the j DC loads are automatically powered from the station batteries.

The DC power distribution system is described in more detail in Bases for LC0 3.8.7, " Distribution System-Operating,"

and LC0 3.8.8, " Distribution System-Shutdown."

Each battery has adequate storage capacity to carry the !

required load. continuously for 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months .

]

(continued) .j Brunswick Unit 2- ,B 3.8-50 Revision No. 6 I i

i DC Sources-0perating B 3.8.4 i

BASES BACKGROUND Each DC battery subsystem (division) is separately housed in (continued) a battery room with its associated chargers and main DC distribution switchboard. This arrangement provides complete separation and isolation of the redundant DC subsystems to ensure that a single failure in one subsystem does not cause a failure in a redundant subsystem.

The batteries for DC electrical power subsystems are sized to produce- required capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles and the 100% design demand. The minimum design voltage limit is 105/210 V.

Each battery charger of DC electrical power subsystem has ample power output capacity for the steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged.

Each station service battery charger has sufficient capacity to restore the battery from the design minimum charge to its fully charged state in approximately 8. hours while supplying normal steady state loads (Ref. 3).

A description of the Unit 1 DC power sources is provided in the Bases for Unit 1 LC0 3.8.4, "DC Sources-Operating".

APPLICABLE The initial conditions of Desis. aasis Accident (DBA) and SAFETY' ANALYSES transient analyses in the UFSAR, Liiapter 6 (Ref. 4) and Chapter 15 (Ref. 5), assume that Engineered Safet) Feature (ESF) systems are OPERABLE. The DC electrical power system provides normal and emergency DC electrical power for the diesel generators (DGs),-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 DC sources OPERABLE during accident conditions in the event of:

a. An assumed loss of all offsite AC power; and

b. A worst case single failure.

The DC sources satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii)

(Ref. 6).

(continued)

Brunswick Unit 2 B 3.8-51 Revision No. 6 l

DC Sources-Operating B 3.8.4 BASES (continued)

LC0: The Unit 2 Division I and Division 11 DC electrical power subsystems, with each DC subsystem consisting of two 125 V batteries (Batteries 2A-1 and 2A-2 for Division I and Batteries 2B-1 and 2B-2 for Division II), two battery chargers (one per battery) and the corresponding control equipment and interconnecting cabling supplying power to the associated bus are required to be OPERABLE to ensure the availability of the required power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (A00) or a postulated DBA. In addition, DC control power for operation of two of the four 4.16 kV emergency buses and two of the four 480 V emergency buses, as well as control power for two of the four DGs, is provided by the Unit 1 DC electrical power subsystems.

Therefore, Unit 1 Division I and Division 11 DC electrical power subsystems are also required to be OPERABLE. Unit 1 DC electrical power subsystem OPERABILITY requirements are the.same as those required for a Unit 2 DC electrical power subsystem. Loss of any DC electrical power subsystem does not prevent the minimum safety function from being performed (Ref. 1).

APPLICABILITY The DC electrical power sources are required to be OPERABLE in MODES 1, 2, and 3 to ensure safe unit operation and to ensure that;

a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of A00s or abnormal transients; and

b. Adequate core cooling is provided, and containment integrity and other vital functions are maintained in the event of a postulated DBA.

The DC electrical power requirements for MODES 4 and 5 and other conditions in which the DC electrical power sources

, are required are addressed in LCO 3.3.5, "DC Sources-Shutdown."

ACTIONS A.1 I l

Pursuant to LCO 3.0.6, the Dist ribution Systems-Operating i ACTIONS would not be entered even if the DC electrical power l subsystem inoperability resulted in de-energization of an AC electrical power distribution subsystem or a DC electrical (continued)

Brunswick Unit 2 B 3.8-52 Revision No. 6 l

m i DC Sources-0perating B 3.8.4 BASES ACTIONS A.1 (continued) power distribution subsystem. Therefore, the Required Actions _of. Condition A are modified by a Note to indicate that when Condition A results in de-energization of an AC electrical power distribution subsystem or a DC electrical power distribution subsystem, Actions of LCO 3.8.7 must be immediately entered. -This allows Condition A to provide requirements for the loss of a DC electrical power subsystem.

without regard to whether a distribution subsystem is de-energized. LCO 3.8.7 provides the appropriate restriction for a de-energized distribution subsystem.

Condition A represents one division with a loss of-ability to completely respond to an event, and a potential loss of ability to remain energized during normal operation. It is therefore imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete loss of DC power to the affected division.

If one of the required nr. electrical power subsystems is inoperable (e.g., inoperable battery, inoperable battery charger (s), or inoperable battery charger and associated inoperable battery), the remaining DC electrical power subsystems have the capacity to support a safe shutdown and to mitigate an accident condition. Since a subsequent worst case single failure could, however, result in the loss of minimum necessary DC electrical subsystems to mitigate a worst case accident, continued power operation should not exceed 7 days. The Completion time is based on the capacity and capability of the remaining DC Sources, including the enhanced reliability afforded by the capability to manually transfer DC loads to the opposite unit's DC electrical power distribution subsystems.

B.1 and B.2 If the DC electrical power subsystem cannot be restored to OPERABLE status within the required Completion Time or if two or more DC electrical power subsystems are inoperable, the unit must be brought to a MODE in which the LC0 does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, (continued)

Brunswick Unit-2 B 3.8-53 Revision No. 6 l'

E.

DC Sources-0perating B 3.8.4 BASES.

ACTIONS B.1 and B.2 (continued) based on operating experience, to reach the required plant conditions from full power conditions in an Orderly manner and without challenging plant systems. The Completion Time to bring the unit to MODE 4 is consistent with the time required in Regulatory Guide 1.93 (Ref. 7).

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 t:1e 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 and maintain the battery in a fully charged state. The voltage requirements are based on the nominal design voltage of the battery. The 7 day Frequency is conservative when compared with manufacturer recommendations and IEEE-450 (Ref. 8).

SR 3.8.4.2 Visual inspection to detect corrosion of the battery cells and connections, or measurement of the resistance of each inter-cell and inter-rack connection, provides an indication of physical damage or abnormal deterioration that could potentially degrade battery performance.

The connection resistance limits are s 1.2 times the established benchmark resistance values for the connections or s 5 ohms above the established benchmark resistance I values for the connections, whichever is higher. These connection resistance acceptance criteria were derived from IEEE-450 (Ref. 8) and IEEE-484 (Ref. 9), respectively. l The Frequency for these inspections, which can detect i conditions that can cause power losses due to resistance -

l heating, is 92 days. This Frequency is consistent with manufacturers. recommendations.

4 (continued)

Brunswick Unit 2 B 3.8-54 Revision No. 6 l

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DC Sources-0perating j

[ B 3.8.4 BASES

]

l . SURVEILLANCE' SR 3.8.4.3 l

REQUIREMENTS (continued) 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 deteriorat' ion does not affect the OPERABILITY of the battery (its ability to perform its design function).

The 18 month Frequency for the Surveillance is based on engineering judgement. 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.

l SR 3.8.4.4 l Visual inspection of inter-cell and inter-rack connections provides an indication of physical damage or abnormal deterioration that could indicate degraded battery condition. The anti-corrosion material 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 this Surveillance.

The 18 month Frequency for the Surveillance is based on engineering. judgement. 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 Battery charger capability requirements are derived from the design capacity of the chargers. According to Reference 3, the battery charger supply is required to be based on the (continued)

Brunswick Unit 2 B 3.8-55 Revision No. 6 i

DC Sources-0perating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.5 (continued) i REQUIREMENTS .

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, {

under any load condition. The minimum required amperes and '

duration ensures that these requirements can be satisfied.

The Frequency-is acceptable, given battery charger reliability and the other administrative controls existing to ensure adequate charger performance during these 24 month intervals. In addition, this frequency is intended to be consistent with expected fuel cycle lengths.

SR 3.8.4.6 A battery service test is a special test of the battery's capability, as found, to satisfy the design requirements (battery duty cycle) of the DC electrical power system. The discharge rate and test length corresponds to the design duty cycle requiremnts as specified in Reference 10.

The Frequency of 24 months is acceptable, given unit conditions required to perform the test and the'other i requirements existing. to ensure adequate battery performance during these 24 month intervals. In addition, this Frequency is intended to be consistent with expected fuel cycle lengths.

This SR is modified by.three Notes. Note 1 allows the performance'of a modified performance discharge test in lieu of a service test once per 60 months. This substitution is ,

acceptable because a modified performance discharge test !

represents a more severe test of battery capacity than SR 3.8.4.6. The reason for Note 2 is that perfo ming the Surveillance would remove. a required DC electrical ,oower subsystem from service, perturb the electrical distribution ;

system, and challenge safety systems. Due to the shared ;

configuration of certain' systems (required to mitigate DBAs ;

and transients) between BNP Units 1 and 2, both Unit I and i Unit 2 DC electrical power subsystems are required to supply power-to these systems when either one or both units are in MODE.1, 2, or.3. In order to reduce the potential ,

consequences associated with removing a required DC 1 electrical _ power subsystem from service during the (continued 1 Brunswick Unit 2 8 3.8-56 Revision No. 6 1

m c DC Sources-0perating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.6 (continued)

REQUIREMENTS performance of this Surveillance, reduce consequences of a potential perturbation to the electrical distribution systems during the performance of this Surveillance, and reduce challenges to safety systems, while at the same time avoiding the need to shutdown both units to perform this.

Surveillance, Note 2 only precludes satisfying this Surveillance for the Unit-2 DC electrical power subsystems when Unit 2 is'in MODE 1 or 2. During the performance of this Surveillance with Unit 2 not in MODE 1 or 2 and with Unit 1 in MODE 1, 2, or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications must be entered if a required DC electrical power subsystem or other supported Technical. Specification equipment is rendered inoperable by the performance of this Surveillance. Credit may be taken for unplanned events that~ satisfy the Surveillance. To minimize testing, Note 3 allows a single test (instead of two tests, one for each unit) to satisfy the requirements for both units. This is allowed since the main purpose of the test can be met by performing the test on a single unit. If a DC electrical power subsystem fails the Surveillance, the DC electrical power subsystem should be considered inoperable for both units.

SR 3.8.4.7 A battery performance discharge test is a test of constant-current capacity of a battery, normally done in the as found l condition, after having been in service, to detect any j change in the capacity determined by the acceptance test. l The test is intended to determine overall battery '

degradation due to age and usage.

A battery modified performance discharge test is a simulated j 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 discharge test, both of which envelope the duty cycle.of the service test. 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.

(continued) 3 1

Brunswick Unit 2 B 3.8-57 Revision No. 6 l 1

DC Sources-0perating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.7 (continued)

REQUIREMENTS The battery terminal voltage for the modified perfermance discharge test should remain above the minimum battery ,

terminal voltage specified in the battery performance i discharge test for the duration of time equal to that of the i performance discharge test. I A modified discharge test is a test of the battery capacity i 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 performance discharge test. Either the battery performance discharge test or the modified performance discharge test is acceptable for satisfying SR 3.8.4.7; however, only the modified performance discharge test may be used to satisfy SR 3.8.4.7 while satisfying the requirements of SR 3.8.4.6 at the same time.

The acceptance criteria for this Surveillance is consistent with IEEE-450 (Ref. 8) and IEEE-485 (Ref,11). These references recommend that the battery be replaced if its capacity is below 80% of the manufacturer's rating. A capacity of 80% shows that the. battery rate of deterioration ;

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 degradation, or if the battery has reached 85%

of its expected life and capacity is < 100% of the manufacturer's rating, the Surveillance Frequency is reduced to 12 months. However, if the battery shows no degradation but has reached 85% of its expected life, the Surveillance Frequency is only reduced to 24 months for batteries that retain capacity 2: 100% of the manufacturer's rating.

Degradation is indicated, according to IEEE-450 (Ref. 8),

when the battery capacity drops by more than 10% relative to its capacity on the previous performance tast or when it is 10% below the manufacturer's rating. The 60 month Frequency is consistent with the recommendations in IEEE-450 (Ref. 8).

The 12 month and 24 month Frequencies are derived from the recommendations in IEEE-450 (Ref. 8).

(continuedl Brunswick Unit 2 B 3.8-58 Revision No. 6 i

7 q i

DC Sources-0perating i B 3.8.4 BASES L

SURVEILLANCE SR 3.8.4.7 (continued)

REQUIREMENTS-This SR is modified by two Notes. The reason for Note 1 is that performing the Surveillance would remove a required DC electrical power subsystem from service, perturb the electrical. distribution system, and challenge safety l systems. 'Due to the shared configuration of certain systems l

.(required to mitigate DBAs and transients) between BNP !

Units.1 and 2, both Unit I and Unit 2 DC electrical power i subsystems are. required to supply power to these systems >

when either one or both units are in MODE 1, 2, or 3. In order to reduta the potential consequences associated with ,

removing a required DC electrical power subsystem from

~

service during the performance of this Surveillance, reduce consequences of a potential perturbation to the electrical distribution systems during the performance of this Surveillance, and reduce challenges to safety systems, while at the same time avoiding the need to shutdown both units to perform this Surveillance, Note 1 only precludes satisfying this Surveillance for the Unit 2 DC electrical power subsystems when Unit 2 is in MODE 1 or 2. During the performance of this Surveillance with Unit 2 not in MODE 1 or 2 and with Unit 1 in MODE 1, 2,- or 3; the applicable ACTIONS of the Unit 1 and Unit 2 Technical Specifications must be entered if a required DC electrical power subsystem or other supported Technical Specification equipment is j rendered inoperable by the performance of this Surveillance.

Credit may be taken for unplanned events that satisfy the Surveillance. To minimize testing, Note 2 allcws a single i test (instead of two tests, one for each unit) to satisfy !

the requirements for both units. This is allowed since the !

main purpose of the test can be met by performing the test on a single unit. If a DC electrical power subsystem fails the Surveillance, the DC electrical power subsystem should be considered inoperable for both units.

REFERENCES- 1. UFSAR, Section 8.3.2.1 l. !

2. Safety Guide 6.

3. UFSAR, Section 8.3.2.1.2.

]

4. UFSAR, Chapter 6.

5. UFSAR, Chapter 15.

(continued)

Brunswick Unit 2 B 3.8-59 Revision No. 6 l l

DC Sources-Operating B 3.8.4 BASES I REFERENCES 6. 10 CFR 50.36(c)(2)(ii).

(continued)

7. Regulatory Guide 1.93, December 1974. '

8. IEEE Standard 450, 1987.

9. IEEE Standard 484, 1996.

10. UFSAR, Section 8.3.2.

11. IEEE Standard 485, 1983. ,

Brunswick Unit 2 B 3.8-60 Revision No. 6 i

W DC Sources-Shutdown B 3.8.5 B 3.8 ELECTRICAL-POWER SYSTEMS B'3.8.5 DC' Sources-Shutdown BASES BACKGROUND A description of the DC sources is provided in the Bases for-LC0' 3.8.4, "DC Sources-Operating."

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

Chapter 15 (Ref. 2), assume that Engineered Safety Feature systems are OPERABLE. The DC electrical power system f

provides normal ~ and emergency DC electrical power for the diesel generators (DGs), emergency auxiliaries, and control and switching during all MODES of operation and during movement of irradiated fuel assemblies in the secondary containment.

The OPERABILITY of the DC subsystems is consistent with the initial assumptions of the accident analyses and the requirements for the supported systems' OPERABILITY.

The OPERABILITY of the minimum DC electrical power sources during MODES 4 and 5 and during movement of irradiated fuel

. assemblies in the secondary containment ensures that: '

a. The facility :an be maintained in the shutdown or refueling conoition for extended periods;

b. Sufficient instrumentation and corirol capability is j available for monitoring and maint ining the unit i status; and

c. Adequate DC electrical power is provided to mitigate events postulated during shutdown, such as an inadvertent draindown of the vessel or a fuel handling accident.

The DC sources' satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii)

(Ref. 3).

LC0 The Unit 2 DC electrical power subsystems each consisting of two 125 V batteries in series, two battery chargers (one per i battery), and the corresponding control equipment and interconnecting cabling supplying power to the associated (continued)

Brunswick Unit 2 B 3.8-61 Revision No. 6 l

DC Sources-Shutdown B 3.8.5 BASES LC0 bus, needed to support required DC distribution subsystems (continued) required OPERABLE by LC0 3.8.8, " Distribution Systems-Shutdown," are required to be OPERABLE. In addition, DC control power for operation of two of_the four 4.16 kV. emergency buses and two of the four 480 V emergency buses, as well as control power for two of the four DGs, is provided by the Unit 1 DC electrical power subsystems.

Therefore, the Unit 1 DC electrical power subsystems needed to support required components.are also required to be OPERABLE. Unit 1 DC electrical power subsystem OPERABILITY requirements are the same as those required for a Unit 2 DC electrical power subsystem. This requirement ensures the availability of sufficient DC electrical power sources to operate the unit in a safe manner and to mitigate the consequences of postulated events during . shutdown (e.g.,

fuel handling accidents and inadvertent reactor vessel draindown).

APPLICABILITY _The DC electrical power sources required to be OPERABLE in MODES 4 and 5 and during movement of irradiated fuel assemblies in the secondary containment provide assurance that:

a. Required features to provide adequate coolant inventory makeup are available for the irradiated fuel assemblies in the core in case of an inadvertent draindown of the reactor vessel;

b. Required features needed to mitigate a fuel handling accident are available;

c. Required features necessary to mitigate the effects of events that can lead to core damage during shutdown are available; and

d. Instrumentation and control capability is available for monitoring and maintaining the unit in a cold I shutdown condition or refueling condition.

The DC electrical power requirements for MODES 1,-2, and 3

. m covered in LCO 3.8.4.

(continued) l Brunswick Unit 2 B 3.8-62 Revision No. 6 l l

DC Sources-Shutdown B 3.8.5 BASES (continued)

ACTIONS LC0 3.0.3 is not applicable while in MODE 4 or 5. However, since irrJiated fuel assembly movement can occur in MODE 1, 2, or 3, the ACTIONS have been modified by a Note stating that LC0 3.0.3 is not applicable. If moving irradiated fuel assemblies while in MODE 4 or 5, LC0 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, or 3, the fuel movement is independent of reactor operations. Entering LC0 3.0.3, while in MODE 1, 2, or 3, would require the unit to be shutdown, but would not require immediate suspension of movement of irradiated fuel assemblies. The Note to the ACTIONS, "LCO 3.0.3 is not applicable," ensures that the actions for immediate suspension of irradiated fuel assembly movement are not ;

postponed due to entry into LC0 3.0.3. l l

A.1, A.2.1, A.2.2, A.2.3, and A.2.4 If more than one DC distribution subsystem is required according to LC0 3.8.8, the DC electrical power subsystems remaining OPERABLE with one or more DC electrical power subsystems inoperable may be capable of supporting sufficient required features to allow continuation of CORE ALTERATIONS, fuel movement, and operations with a potential for draining the reactor vessel. By allowance of the option to declare required features inoperable with associated DC electrical power subsystem (s) inoperable, appropriate restrictions are implemented in accordance with the affected system LCOs' ACTIONS. However, in many instances, this option may involve undesired administrative efforts.

Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movement cf irradiated fuel assemblies in the secondary containment, and any activities that could result in inadvertent draining of the reactor vessel).

Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition.

These actions minimize the probability of the occurrence of postulated events. it is further required to immediately initiate action to restore the required DC electrical power subsystems and to continue this action until restoration is accomplished in order to provide the necessary DC electrical power to the plant safety systems.

(continued)

Brunswick Unit 2 B 3.8-63 Revision No. 6 i

DC Sources-Shutdown B 3.8.5 BASES ACTIONS -A.I. A.2.1, A.2.2, A.2.3. and A.2.4 (continued)

The Completion Time of immediately is consistent with the required times for actions requiring' prompt attention. The restoration of the required DC electrical power subsystems should be completed as quickly as possible in order to minimize the time during which the plant safety systems may be without sufficient power.

SURVEILLANCE SR 3.8.5.1 REQUIREMENTS SR 3.8.5.1 requires certain Surveillances required by LC0 3.8.4 to be met. Therefore, see the corresponding Bases for LC0 3.8.4 for a discussion of each SR.

This SR is modified by a Note. The reason for the Note is to preclude requiring the OPERABLE DC sources from being discharged below their capability to provide the required power supply or otherwise rendered inoperable during the performance of SRs. It is the intent that these SRs must still be capable of being met, but actual performance is not required unless Unit 1 Specification 3.8.4, "DC Sources-0perating," requires performance of these SRs.

When Unit 1 Specification 3.8.4 requires performance of these SRs, DC source availability is not limited, due to the Unit I requirements for DC source OPERABILITY. Therefore, in this condition, other DC sources would be available to supply the required loads.

REFERENCES 1. UFSAR, Chapter 6.

2. UFSAR, Chapter 15.

3. 10 CFR 50.36(c)(2)(ii).

Brunswick Unit 2 8 3.8-64 Revision No. 6 1

Battery Cell Parameters B 3.8.6 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.6 Battery Cell Parameters

?

BASES BACKGROUND This LC0 delineates the limits on electrolyte temperature, level', float voltage, and specific gravity for the DC electrical power subsystems batteries. A discussion of {

these batteries ~and their OPERABILITY requirements is !

provided. in the Bases for. LCO 3.8.4, "DC Sources- 1 Operating," and . LCO 3.8.5, "DC Sources-Shutdown."

i APPLICABLE The initial- conditions. of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in UFSAR, Chapter 6 (Ref. 1) and Chapter 15 (Ref. 2), assume Engineered Safety Feature systems are OPERABLE. 'The DC electrical' power subsystems )

provide normal and emergency DC electrical power for.the

~

diesel generators (DGs), emergency auxiliaries, and control and switching during all MODES of operation.

The OPERABILITY'of the DC subsystems is consistent with the i initial assumptions of the accident analyses and is based l upon meeting the design basis of the unit as discussed in .

the Bases for LC0 3.E 4 and LC0 3.8.5. !

l Since battery cell parameters support the operation of the DC electrical power subsystems, they satisfy Criterion 3 of ;

10 CFR 50.36(c)(2)(ii) (Ref.-3).

LC0 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 j and B limits not met.

I APPLICABILITY The battery cell parameters are required solely for the support of the associated DC electrical power subsystem.

Therefore, these cell parameters are only required when the associated DC electrical power subsystem is required to be OPERABLE. Refer to the Applicability discussions in Bases for LC0 3.8.4 and LC0 3.8.5.

(continued)

Brunswick Unit 2- B 3.8-65 Revision No. 6 l

Battery Cell Parameters i B 3.8.6 i BASES (continued) l ACTIONS The ACTIONS Table is modified by a Note indicating that a

, separate Condition entry is allowed for each battery. This l is acceptable, since the Required Actions for each Condition

provide appropriate compensatory actions for each battery with battery cell parameters not within limits. Complying with the Required Actions may allow for continued operation, l and subsequent batteries with battery cell parameters not I

within limits are governed by subsequent Condition entry and application of associated Required Actions.

A.1, A.2, and A.3 With parameters of one or more cells in one or more batteries not within limits (i.e., Category A limits not met or Category B limits not met, or Category A and B limits not l met) but within the Category C limits specified in 1 Table 3.8.6-1, 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 continued operation is permitted for a limited period.

The pilot cell (s) electrolyte level and float voltage are required to be verified to meet the Category C limits within I hour (Required Action A.1). This check provides 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 cell (s).

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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is allowed to complete the initial verification because specific gravity measurements I

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 (continued) i Brunswick Unit 2 B 3.8-66 Revision No. 6 l l

l

Battery Cell Parameters B 3.8.6 BASES ACTIONS A.I. A.2, and A.3 (continued) 7 day intervals until the parameters are restored to Category A and B limits. This periodic verification is consistent with the normal Frequency of pilot cell Surveillances.

Continued operation prior to declaring the affected batteries inoperable is permitted for 31 days before battery cell parameters must be restored to within Category A and B limits. Taking into 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 for operation prior to declaring the DC batteries inoperable.

B.1 When any battery parameter is outside the Category C limit for any connected cell, sufficient capacity to supply the maximum expected load requirement is not ensured and the corresponding DC electrical power subsystem must be declared inoperable. Additionally, other potentially extreme conditions, such as any Required Action of Condition A and associated Completion Time not met or average electrolyte temperature of representative cells < 60*F, also are cause for immediately declaring the asscciated DC electrical power subsystem inoperable.

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.

SR 3.8.6.2 The quarterly inspection of specific gravity and voltage is consistent with IEEE-450 (Ref. 4).

(continued)

Brunswick Unit 2 B 3.8-67 Revision No. 6 l

)

Battery Cell Parameters B 3.8.6 )

. BASES 1

SURVEILLANCE .SR 3.8.6.3 REQUIREMENTS (continued) This Surveillance verification-that the average temperature of' representative cells is within limits'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's recommendations and the battery sizing calculations.

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 designed 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's recommendat %.s and are consistent with the guidance in IEEE-450 (Ref. 4), with the extra 1 inch allowance above the high water level indication for I operating margin to account for temperature and charge effects. In addition to this allowance, Footnote.(a)'to Table 3.8.6-1 permits the electrolyte level to be temporarily above the specified maximum level during and' following equalizing charge (i.e., for up to 3 days following the completion of an equalize 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

(continuedl Brunswick Unit 2 B 3.8-68 Revision No. 6 l u.

g Battery Cell Parameters B 3.8.6 BASES

. SURVEILLANCE Table 3.8.6-1 (continued)-

REQUIREMENTS

'The Category A limit specified for float voltage is 2 2.13 V per cell. This.value is based on the manufacturer's recommendations and on the recommendation of IEEE-450 (Ref. 4), which states that prolonged operation of cells below 2.13 V can reduce the life expectancy of cells. The Category A limit specified 'for specific gravity for each i pilot cell is 2 1.200 (0.015 below the manufacturer's fully charged nominal specific gravity or a battery charging cu'* rent 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'F (25'C).

The specific gravity readings are corrected for actual electrolyte temperature and level. 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. Level correction will be in accordance with manufacturer's.

recommendations.

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 j and have been discussed above. The Category B limit specified for specific gravity for each connected cell is !

2 1.195 (0.020 below the manufacturer's fully charged, nominal specific gravity) with the average of all connected cells a 1.205 (0.010 below the manufacturer's fully charged, nominal specific gravity). These values are based on manufacturer's recommendations. The minimum specific gravity value required for each cell ensures that a cell with a marginal or unacceptable specific gravity is not masked by averaging cells having higher specific gravities.

Category C defines the limits for each connected cell.

These values, although reduced, provide assurance that-sufficient capacity exists to perform the intended function (continued)

Brunswick Unit 2 B 3.8-69 Revision No. 6 i

Battery Cell Parameters B 3.8.6 BASES SURVEILLANCE Table 3.8.6-1 (continued)

REQUIREMENTS 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 limit specified for electrolyte level (above the top of the plates and not overflowing) ensures that the plates suffer no physical damage and maintain adequate electron transfer capability. The Category C limit for voltage is based on IEEE-450, Appendix C (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 repl acement .

The Category C limit on average specific gravity 2: 1.195, is based on manufacturer's recommendations (0.020 below the manufacturer's 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 a cell with a marginal or unacceptable specific gravity-is not masked by averaging with cells having higher specific gravities. i The footnotes to Table 3.8.6-1 that apply to specific gravity are applicable to Category A, B, and C specific i gravity. Footnote (b) requires the above mentioned i correction for electrolyte level and temperature, with the exception that level correction is not required when battery !

charging current, while on float charge, is < 2 amps. This current provides, in general, an indication of acceptable 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 charging current is an acceptable alternative to specific gravity measurement for determining the state of charge of the designated pilot cell. This phenomenon is discussed in IEEE-450 (Ref. 4). Footnote (c) allows the float charge current to be used as an alternate to specific (continued)

Brunswick Unit 2 B 3.8-70 Revision No. 6 1

r Battery Cell Parameters B 3.8.6 BASES SURVEILLANCE- Table 3.8.6-1 -(continued)

REQUIREMENTS gravity for up to 7 days following a battery recharge.

Within 7 days, each connected cell's specific gravity must I

be measured'to confirm the state of charge. Following.a- I 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.

-REFERENCES' 1. UFSAR, Chapter 6.

2. UFSAR, Chapter 15.

3. 10 CFR 50.36(c)(2)(ii).

4. IEEE Standard 450, 1987. j l

l 1

l l

i I

i

)

' Brunswick Unit 2 B 3.8-71 Revision No. 6 I

Distribution Systems-0perating B 3.8.7 l

B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.7 Distribution Systems-Operating l

BASES BACKGROUND The onsite Class lE AC and DC electrical power distribution system is divided into redundant and independent AC and DC electrical power distribution subsystems.

The Class lE AC electrical distribution system is divided into four load groups. Each load group consists of a primary emergency bus, its downstream secondary emergency bus, 120 VAC vital bus, and transformers and interconnecting cables. The buses associated with each of the four load groups are defined as follows:

Load group El consists of 4.16 kV bus El, 480 V bus E5, and 120 VAC vital bus lES. )

Load group E2 consists of 4.16 kV bus E2, 480 V bus E6, and 120 VAC vital bus lE6.

Load group E3 consists of 4.16 kV bus E3, 480 V ,

bus E7, and 120 VAC vital bus 2E7. '

Load group E4 consists of 4.16 kV bus E4, 480 V bus E8, and 120 VAC vital bus 2E8.

The El and E2 load groups are supplied from Unit 1 balance i of plant (BOP) buses and primarily serve Unit I loads. The E3 and E4 load groups are supplied from Unit 2 B0P buses and primarily serve Unit 2 loads. In some instances loads associated with one unit are actually supplied from the opposite unit's load group buses.

Each primary emergency bus (4.16 kV emergency bus) has access to two offsite sources of power via a common circuit path from its associated upstream B0P bus (master / slave breakers and interconnecting cables). In addition, each 4.16 kV emergency bus can be provided power from an onsite diesel generator (DG) source. The upstream B0P bus associated with each 4.16 kV emergency bus is normally connected to the main generator output via the unit auxiliary transformer. During a loss of the normal power source to the 4.16 kV BOP bus, the preferred source supply breaker attempts to close. If all offsite sources are (continued)

Brunswick Unit 2 B 3.8 Revision No. 6 l

Distribution Systems-0perating B 3.8.7 I

l BASES !

l BACKGROUND unavailable, the affected 4.16 kV emergency bus is isolated l (Continued) from its associated upstream 4.16 kV BOP bus and the onsite ;

emergency DG will supply power to the 4.16 kV emergency bus. '

Control power for each 4.16 kV emergency bus is supplied ;

from a Class lE battery with manual transfer capability to l another Class lE battery. Additional descriptions of this 1 system may be found in the Bases for Specification 3.8.1, "AC Sources-Operating," and the Bases for Specification 3.8.4, "DC Sources-0perating".

The secondary plant distribution system includes 480 VAC emergency buses ES, E6, E7, and E8 and associated motor control centers (MCCs), transformers, and interconnecting cables. Secondary emergency buses ES, E6, E7, and E8 are supplied from primary emergency buses El, E2, E3, and E4, respectively. Control power for each 480 VAC emergency bus is supplied from a Class lE battery with manual transfer capability to another Class IE battery. Additional ,

descriptions of this system may be found in the Bases for )

Specification 3.8.4, "DC Sources-Operating". j The 120 VAC vital buses lES, lE6, 2E7, and 2E8 are arranged in four load groups and are powered from secondary emergency buses ES, E6, E7, and E8, respectively.

There are two independent 125/250 VDC electrical power l distribution subsystems.

The list of required distribution buses is presented in l Table B 3.8.7-1.

APPLICABLE The initial conditions of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in the UFSAR, Chapter 6 (Ref.1) and i Chapter 15 (Ref. 2), assume Engineered Safety Feature (ESF) systems are OPERABLE. The AC and DC electrical power l distribution systems are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems so that the fuel, Reactor Coolant System, and containment design limits are not exceeded. These limits are discussed in more detail-in the Bases for Section 3.2, " Power Distribution Limits"; Section 3.5, " Emergency Core Cooling System (ECCS) I and Reactor Core Isolation Cooling (RCIC) System"; and Section 3.6, " Containment Systems."

(continued)

Brunswick Unit 2 8 3.8-73 Revision No. 6 l l

Distribution Systems-Operating B 3.8.7 BASES APPLICABLE The'0PERABILITY of the AC and DC electrical power SAFETY ANALYSES distribution subsystems is consistent with the initial

.(continued) assumptions of the accident analyses and is based upon meeting the design basis of the unit. This includes maintaining distribution systems OPERABLE during accident conditions in the event of:

a. An assumed loss of all~offsite power; and

b. A worst case single failure.

The AC and DC electrical power distribution system satisfies Criterion 3 of 10 CFR 50.-36(c)(2)(ii) (Ref. 3).

LC0 The required electrical power distribution subsystems listed )

in Table B 3.8.7-1 ensure the availability of AC and DC electrical power for the systems required to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (A00) or a postulated DBA. The Unit 2 AC and DC electrical power distribution subsystems are required to be OPERABLE. In addition, since i

some components required by Unit 2 receive power through 1 Unit 1 DC electrical power distribution subsystems (e.g., l control power for two of the four 4.16 kV emergency buses, '

two of the four 480 VAC emergency buses, and for two of the DGs, and two of four engineered safeguard w tem (ESS) panels), the Unit 1 DC electrical power dirtribution subsystems needed to support the required 2quipment must also be OPERABLE. As stated in Table B 3.8.7-1, each division of the AC and DC electrical power distribution !

systems is.a subsystem. 1 Maintaining the Division I and 11 AC and DC electrical power l distribution subsystems OPERABLE ensures that the redundancy ,

incorporated into the design of ESF is not defeated. l Therefore, a single failure within any system or within the electrical power distribution subsystems will not prevent safe shutdown of the reactor.

The AC electrical power distribution subsystems require the !

associated buses and electrical circuits to be energized to their_ proper voltages. The DC electrical power distribution subsystems require the associated buses to he energized to their proper voltage from either the associated batteries or l chargers.

(continued)

Brunswick Unit' 2~ B 3.8-74 Revision No. 6 l

I Distribution Systems-0perating 8 3.8.7 BASES LC0 Based on the number of safety significant electrical loads (continued) associated with each bus listed in Table B 3.8.7-1, if one or more of the buses becomes inoperable, entry into the appropriate ACTIONS of LCO 3.8.7 is required. Other buses, such as MCCs.and distribution panels, which help comprise the AC and DC distribution systems are not listed in Table B 3.8.7-1. The loss of electrical loads associated with these buses may not result in a complete loss of a redundant safety function necessary.to shut down the reactor and maintain it in a safe condition. Therefore, should one or more of these buses become inoperable due to a failure not affecting the OPERABILITY of a bus listed in Table.B 3.8.7-1 (e.g., a breaker supplying a single MCC fails open), the individual loads on the bus must be declared inoperable, and the appropriate Conditions and Required Actions of the LCOs governing the individual loads would be entered. 'However, if one or more of these buses is inoperable due to a failure also affecting the OPERABli.ITY of a bus listed in Table B 3.8.7-1'(e.g., loss of a 4.16 kV emergency bus, which results in de-energization of all buses powered from the 4.16 kV emergency bus), then although the individual loads are still considered inoperable, the Conditions and Required Actions of the LCO for the individual loads are not required to be entered, since LCO 3.0.6 allows this exception (i.e., the loads are inoperable due to the inoperability of a support system governed by a Technical Specification; the 4.16 kV emergency bus).

In addition, tie breakers and transfer switches between redundant safety related AC and DC power distribution subsystems, if they exist, must be open. This includes control power transfer switches associated with the 4.16 kV and 480 V emergency buses and transfer switches associated with the ESS and DG panels. This prevents any electrical malfunction in any power distribution subsystem from propagating to the redundant subsystem, which could cause the failure of a redundant subsystem and a loss of essential safety function (s). If any tie breakers are closed or transfer switches aligned to the alternate supply, the j affected redundant electrical power distribution subsystems are considered inoperable. This applies to the onsite, safety related, redundant electrical power distribution subsystems. It does not, however, preclude redundant Class IE 4.16 kV emergency buses from being powered from the same offsite circuit.

(continued)

Brunswick Unit 2 B 3.8-75 Revision No. 6 l

m Distribution Systems-0perating B 3.8.7 BASES (continued)

APPLICABILITY The electrical power distribution subsystems are required to be' OPERABLE in MODES 1, 2, and 3 to ensure that:

a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of A00s or abnormal transients; and

b. Adequate core cooling is provided, and containment OPERABILITY and other vital functions are maintained in the event of a postulated DBA.

Electrical power distribution subsystem requirements for MODES 4 and 5 and other conditions in which AC and DC electrical power distribution subsystems are required are covered in the Bases for LC0 3.8.8, " Distribution Systems -Shu tdown . "

ACTIONS A.1 With one AC electrical power distribution subsystem inoperable due to either inoperable load group El bus (es),

or inoperable load group E2 bus (es), the remaining AC electrical power distribution load groups are capable of supporting the minimum safety functions necessary to shut down the operating reactor and maintain both reactors in a safe condition, assuming no single failure in the remaining AC electrical power distribution load groups, when Unit 1 is in MODE 4 or 5. -(If Unit 1 is in MODE 1, 2, or 3, then the Unit 1 ACTIONS of Specification 3.8.7, " Distribution Systems-Operating," require restoration of the associated AC electrical power distribution subsystem within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months of the inoperability.) The overall reliability is reduced in Condition A, because a single failure in a remaining load group could result in the minimum required ESF functions not being supported. As a result, Required Action A.1 limits the i time period to perform planned maintenance on a Unit 1 load i group to 7 days. This is acceptable based on the following: l

a. The other unit's' load group buses are not as critical !

to the operating unit (fewer operating unit loads) as the operating unit's load grbup buses. !

b. Performing maintenance on these components will ;

increase the reliability of the Class lE AC Electrical

^

Power Distribution System.

(continued)

Brunswick Unit 2 8 3.8-76 Revision No. 6 1

i Distribution Systems-0perating B 3.8.7 BASES-ACTIONS A.1 (continued)

c. The 7 day Completion Time provides a reasonable time frame for performance of planned maintenance.

During the planned maintenance of the load group buses, if a condition is discovered on these buses requiring corrective maintenance, this maintenance may be performed within the 7 day Completion Time of Required Action A.l.

The Class 1E AC Electrical Power Distribution System is divided into four load groups. Each load group consists of a primary emergency bus, its downstream secondary emergency bus,120 VAC vital bus, and transformers and interconnecting cables. The buses associated with each of the four load groups are defined as follows:

Load group El consists of 4.16 kV bus El, 480 V bus E5, and 120 VAC vital bus IES.

Load group-E2 consists of 4.16 kV bus E2, 480 V bus E6, and 120 VAC vital bus lE6.

Load group E3 consists of 4.16 kV bus E3, 480 V bus E7, and 120 VAC vital bus 2E7.

Load group E4 consists of 4.16 kV bus E4, 480 V bus E8, and 120 VAC vital bus 2E8.

The second Completion Time for Required Action A.1 ;

establishes a limit on the maximum time allowed for any l combination of required distribution subsystems to be !

inoperable during any single contiguous occurrence of '

failing to meet the LCO. If Condition A is entered while, ;

for instance, an AC bus in a load group in a different division is' inoperable and subsequently returned OPERABLE, j this LCO may already have been not met for up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

This situation could lead to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months (since initial failure to meet the LCO) to restore the AC ,

Electrical Power Distribution System. At this time an AC l bus in a load group in a different division could again !

'become inoperable, and the load group removed under Condition A could be restored OPERABLE. This could continue indefinitely. 1 (continued 1 Brunswick Unit-2 B 3.8-77 Revision No. 6 I

i.

Distribution Systems-0perating B 3.8.7 BASES ACTIONS A.1 (continued)

This Completion Time allows for an exception to the normal

" time zero" for beginning the allowed outage time _" clock".

This results in establishing the " time zero" at the time this.LC0 was initially _ not met, instead of at the time Condition A was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Completion Time is an acceptable limitation on this potential to fail to meet the l LC0 indefinitely.

l If while in Condition A, emergency buses associated with another load group become inoperable (e.g., buses in load 'l

, groups El and E2 are concurrently inoperable), Condition B i and F must be entered, as appropriate.

B.1 l l

With one or more required AC buses or distribution panels in one. division inoperable for reasons o'.her than Condition A, I the remaining AC electrical power distribution subsystems are capable _of supporting the minimum safety functions necessary to shut down.the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in

, the remaining AC electrical power distribution subsystems-l could result in the minimum required ESF functions not being l

supported. Therefore, the required AC buses, and-distribution panels must be restored to OPERABLE status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

The Condition B worst scenario is one division without AC l l power'(i.e., no offsite power to the division and the ;

associated DG inoperable). -In this Condition, the unit is i more vulnerable to a complete loss of AC power. It is, therefore, imperative that the unit operators' attention be focused on minimizing the potential for loss of power to the remaining division by stabilizing the unit and restoring power to the affected division. The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months time ' limit

before requiring a unit shutdown in this Condition is l accentable because of. ;

i l __ (continued) !

i l

Brunswick Unit 2 B 3.8-78 Revision No. 6 l m

I Distribution Systems-Operating B 3.8.7 BASES ACTIONS B.1 (continued) {

a. The potential for decreased safety if the unit operators' attention is diverted from the evaluations !

and actions necessary to restore power to the affected division to the actions associated with taking the unit to shutdown within this time limit.

b. The low potential for an event in conjunction with a j single failure of a redundant component in the division with AC power. (The redundant component is verified OPERABLE in accordance with Specification 5.5.11, " Safety Function Determination Program (SFDP).")

The second Completion Time for Required Action B.1 establishes a limit on the maximum time allowed for any combination of required distribution subsystems to be inoperable during any single contiguous occurrence of failing to meet the LCO. If Condition B is entered while, for instance, a DC bus is inoperable and subsequently returned OPERABLE, this LC0 may already have been not met i for up to 7 days. This situation could lead to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months , since initial failure to meet the l LCO, to restore the AC electrical power distribution system. l At this time a DC bus could again become inoperable, and the l AC electrical power distribution system could be restored i OPERABLE. This could continue indefinitely.

This Completion Time allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

This results in establishing the " time zero" at the time this LCO was initially not met, instead of at the time Condition B was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Completion Time is an acceptable limitation on this potential to fail to meet the LC0 indefinitely.

C.l. C.2. C.3 and C.4 Condition C applies to the 125 VDC buses listed in Table B 3.8.7-1 which can be supplied from either a normal or an alternate DC source. These buses are listed below:

a. 125 VDC Control Power Buses for 4.16 kV Switchgear El, E2, E3, and E4; (continued)

Brunswick Unit 2 B 3.8-79 Revision No. 7 l l

Distribution Systems-Operating i B 3.8.7 BASES ACTIONS C.I. C.2. C 3 and C.4 (continued) l b. 125 VDC Control Power Buses for 480 V Switchgear E5, E6, E7, and E8;

c. 125 VDC ESS Logic Cabinets H58, H59, H60, and H61; and

d. 125 VDC DG Pnnels DG-1, DG-2, DG-3, and DG-4.

Condition A permits the de-energization of the El load group bus (es) or the E2 load group bus (es) for planned maintenance when Unit 1 is in MODE 4 or 5. During a 4.16 kV or 480 V bus out ge it is desirable to clear both the normal and alternate sources of DC control power to the bus for !

personnel safety. The de-energized AC bus is inoperable and not capable of supplying its loads regardless of the availability of DC control power. Hence, entry into )

Condition C as a result of performing maintenance under ;

Condition A is not necessary; Condition D would apply.

With one or more DC electrical power distribution subsystems l inoperable due to loss of normal DC source, the remaining DC l electrical power distribution subsystem (s) are capable of supporting the minimum safety functions necessary to l shutdown the reactor and maintain it in a safe shutdown condition, provided safety function is not lost and assuming no single failure. However, the overall reliability is reduced because a single failure in the DC electrical power distribution system could result in a loss of two of four AC electrical load groups and the minimum required ESF functions not being supported. Therefore, action must be immediately initiated to transfer the DC electrical power distribution system to its alternate source and the affected supported equipment immediately declared inoperable. Upon completion of the transfer of the affected supported equipment's DC electrical power distribution subsystem to its OPERABLE alternate DC source, the affected supported equipment may be declared OPERABLE again. The ESS logic

cabinets transfer automatically upon loss of the normal source. For an ESS logic cabinet, verification that the l automatic transfer has occurred and alternate power is available to the ESS logic cabinet will satisfy Required Action C.2. By allowance of the option to declare affected i supported equipment inoperable with associated DC electrical power distribution subsystems inoperable due to loss of (continued)

Brunswick Unit 2 B 3.8-80 Revision No. 7 I I

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Distribution Systems-0perating l

B 3.8.7 BASES ACTIONS C.I. C.2. C.3 and C.4 (continued) normal DC source, more conservative restrictions are implemented in accordance with the affected system LCOs' !

ACTIONS. When any control power transfer switch associated '

with the 4.16 kV and 480 V emergency buses or any transfer switch associated with the ESS and DG panels is transferred to the alternate source, a single failure in the DC system could render two of four AC electrical load groups innperable. Therefore, to prevent indefinite operation in this degraded condition, power from the normal DC source I must be restored in 7 days. l l

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. ,

Required Actions C.1 and C.2 should be completed as quickly i as possible. The 7 day Completion Time of Required '

Action C.4 is considered to be acceptable due to the low potential for an event in conjunction with a single failure of a redundant component and is consistent with the allowed Completion Time for an inoperable DC electrical power subsystem specified in Specification 3.8.4, "DC Sources-Operating."

l 1

The second Completion Time for Required Action C.4 establishes a limit on the maximum time allowed for any combination of required electrical power distribution subsystems to be inoperable during any single contiguous occurrence of failing to meet the LCO. If Condition C is l entered while, for instance, an AC bus is inoperable and subsequently restored OPERABLE, the LC0 inay already have 1 been not met for up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . This situation could lead l to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months , since initial failure to meet the LCO, to restore the DC electrical power distribution system. At this time, an AC bus could again become inoperable, and the DC electrical power distribution system could be restored OPERABLE. This could continue indefinitely. -

This Completion Time allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

This allowance results in establishing the " time zero" at the time the LC0 was initially not met, instead of at the time Condition C was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Completion Time is an acceptable limitation on this potential of failing to meet the LCO indefinitely.

(continuedl Brunswick Unit 2 B 3.8-81 Revision No. 7 1

Distribution Systems-Operating B 3.8.7 BASES ACTIONS p_d (continued)

With one DC electrical power distribution subsystem inoperable for reasons other than Condition C, the remaining DC electrical power distribution subsystem is capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in the remaining DC electrical power distribution subsystem could result in the minimum required ESF functions not being supported. Therefore, the required DC electrical power distribution subsystem must be restored to OPERABLE status within 7 days by powering the bus from the associated batteries or chargers.

Condition D represents one division without adequate DC power, potentially with both the battery (s) significantly degraded and the associated charger (s) nonfunctioning. In this situation the plant is significantly more vulnerable to a complete loss of all DC power. It is, therefore, imperative that the operator's attention focus on stabilizing the plant, minimizing the potential for loss of power to the remaining divisions, and restoring power to the affected division.

The 7 day Completion Time is consistent with the allowed Completion Time for an inoperable DC electrical power subsystem specified in Specification 3.8.4, "DC Sources-Operating". Taking exception to LC0 3.0.2 for components without adequate DC power, which would have Required Action Completion Times shorter than 7 days, is acceptable because of:

a. The potential for derreased safety when requiring a change in plant conditions (i.e., requiring a shutdown) while not allowing stable operations to continue;

b. The potential for decreased safety when requiring entry into numerous applicable Conditions and Required Actions for components without DC power, while not providing sufficient time for the operators to perform the necessary evaluations and actions for restoring power to the affected division; (continued) 1 Brunswick Unit 2' B 3.8-82 Revision No. 7 l

Distribution Systems-0perating B 3.8.7 BASES ACTIONS D.1 (continued)

c. The low potential for an event in conjunction with a single failure of a redundant component.

The second Completion Time for Required Action D.1 establishes a limit on the maximum time allowed for any combination of required electrical power distribution subsystems to be inoperable during any single contiguous occurrence of failing to meet the LCO. If Condition D is entered while, for instance, an AC bus is inoperable and subsequently restored OPERABLE, the LC0 may already have been not met for up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . This situation could lead to a total duration of 176 hours0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months , since initial failure to meet the LCO, to restore the DC electrical power distribution system. At this time, an AC bus could again become inoperable, and the DC electrical power distribution system could be restored OPERABLE. This could continue indefinitely.

This Completion Time allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

This allowance results in establishing the " time zero" at the time the LCO was initially not met, instead of at the time Condition D was entered. The 176 hour0.00204 days 0.0489 hours 2.910053e-4 weeks 6.6968e-5 months Completion Time is an acceptable limitation on this potential of failing to meet the LC0 indefinitely.

E.1 and E.2 If the inoperable electrical power distribution subsystem (s) cannot be restored to OPERABLE status within the associated Completion Time, the unit must be brought to a MODE in which the LC0 does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed.. Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

(continued)

Brunswick Unit 2 B 3.8-83 Revision No. 7 l

E 1 Distribution Systems-Operating l B 3.8.7 BASES l j ACTIONS F.1 (continued)

Condition F corresponds to a level of degradation in the l' electrical power distribution system that causes a required safety function to be lost. When more than one AC or DC electrical power distribution subsystem is lost, and this results in the loss of a required function, the plant is in a condition outside the accident analysis. Therefore, no additional time is justified for continued operation. i l

LC0 3.0.3 must be entered immediately to commence a controlled shutdown.

SURVEILLANCE SR 3.8.7.1 ;

REQUIREMENTS l This Surveillance verifies that the AC and DC electrical power distribution systems are functioning properly, with i the correct circuit breaker alignment. This includes verifying that distribution bus tie breakers are open and ,

control power transfer switches associated with the 4.16 kV l and 480 V emergency buses and transfer switches associated I with the ESS and DG panels are aligned to their normal DC l sources. The correct breaker alignment ensures the appropriate separation and independence of the electrical buses are maintained, and power is available to each required bus. The verification of energization of the buses ensures that the required power is readily available for motive as well as control functions for critical system loads connected to these buses. This may be performed by verification of absence of low voltage alarms or by verifying a load powered from the bus is operating. The 7 day Frequency takes into account the redundant capability of the AC and DC electrical power distribution subsystems, and other indications available in the control room that alert the operator to subsystem malfunctions.

SR 3.8.7.2 This Surveillance verifies that no combination of more than two power conversion modules (consisting of either two lighting inverters or one lighting inverter and one plant uninterruptible power supply unit) are aligned to Division II (bus B). Two power conversion modules aligned to Division II (bus B) was an initial assumption in the DC battery load study. Limiting two power conversion modules (continued)

Brunswick Unit 2 B 3.8-84 Revision No. 7 1 i

Distribution Systems--Operating l B'3.8.7 ,

1 BASES i

SURVEILLANCE- SR 3.8.7.2 '(continued)

REQUIREMENTS to be aligned to Division II ensures the associated batteries will, supply DC power to safety related equipment during a design basis event. The 7 day Frequency takes into account the. redundant capability of the DC electrical power distribution subsystems and indications available in the i control room to alert the operator of power conversion module misalignment.

REFERENCES 1. UFSAR, Chapter 6. l

2. UFSAR, Chapter 15. '

3. 10 CFR 50.36(c)(2)(ii).

4 Brunswick Unit 2 B 3.8-85 Revision No. 7 1

Distribution Systems-Operating B 3.8.7 Table B 3.8.7-1 (page 1 of 1)

AC and DC Electrical Power Distribution Systems TYPE VOLTAGE DIVISION I(a) DIVISION II(a)

AC emergency 4160 V Emergency Buses Emergency Buses buses El, E3 E2, E4 480 V Emergency Buses Emergency Buses ES, E7 E6, E8 AC vital buses 120 V Distribution Distribution Panels Panel s IES, 2E7 IE6, 2E8 l DC buses 250 V Switchboard 2A Switchboard 2B 125 V ESS logic ESS logic Cabinets Cabinets H58, H60 H59, H61 1

125 V DG Panels DG Panels )

DG-1, DG-3 DG-2, DG-4 l

DC control 125 V 4.16 kV Switchgear 4.16 kV Switchgear !

power buses El, E3 E2, E4 l 125 V 480 V 480 V Switchgear Switchgear ES, E7 E6, E8 0

l (a) Each division of the AC and DC electrical power distribution systems is a subsystem.

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l Brunswick Unit 2 B 3.8-86 Revision No. 7 l l l

Distribution Systems-Shutdown B 3.8.8 8 3.8 ELECTRICAL POWER SYSTEMS B 3.8.8 Distribution Systems-Shutdown BASES BACKGROUND A description of the AC and DC electrical power distribution system is provided in the Bases for LC0 3.8.7, " Distribution Systems-Operating. "

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

Chapter 15 (Ref. 2), assume Engineered Safety Feature (ESF) l systems are OPERABLE. The AC and DC electrical power

{

distribution systems are designed to provide sufficient i capacity, capability, redundancy, and reliability to ensure {

the availability of necessary power to ESF systems so that l the fuel, Reactor Coolant System, and containment design i limits are not exceeded.

The OPERABILITY of the AC and DC electrical power distribution system is consistent with the initial assumptions of the accident analyses and the requirements for the supported systems' OPERABILITY.

The OPERABILITY of the minimum AC and DC electrical power sources and associated power distribution subsystems during MODES 4 and 5, and during movement of irradiated fuel assemblies in the secondary containment ensures that:

a. The facility can be maintained in the shutdown or refueling condition for extended periods;

b. Sufficient instrumentation and control capability is available for monitoring and maintaining the unit status; and

c. Adequate power is provided to mitigate events postulated during shutdown, such as an inadvertent draindown of the vessel or a fuel handling accident.

The AC and DC electrical power distribution systems satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii) (Ref. 3).

(continued)

Brunswick Unit 2 B 3.8-87 Revision No. 7 l

'l

)

Distribution Systems-Shutdown B 3.8.8 BASES (continued) 4 LC0 Various combinations of subsystems, equipment, and components are required OPERABLE by other LCOs, depending on the specific plant condition. Implicit in those )

requirements is the required OPERABILITY of necessary support features. This LC0 explicitly requires energization of the portions of the electrical distribution system necessary to support OPERABILITY. of Technical Specifications required systems, equipment, and components-both specifically addressed by their own LCO, and implicitly .

required by the definition of OPERABILITY. In addition, DC l control power for operation of two of the four 4.16 kV emergency buses and two of the four 480 V emergency buses, as wall as control power for two of the four diesel {

generators, is provided by the Unit 1 DC electrical power '

subsystems. Therefore, the Unit 1 DC electrical power distribution subsystems needed to support required components are also required to be OPERABLE.

In addition, it is acceptable for required buses to be cross-tied during shutdown conditions, permitting a single source to supply multiple redundant buses, provided the source is capable of maintaining proper frequency (if required) and voltage.

Maintaining these portions of the distribution system energized ensures the availability of sufficient power to operate the plant in a safe manner to mitigate the consequences of postulated events during shutdown (e.g.,

fuel handling accidents and inadvertent reactor vessel ,

draindown).

1 APPLICABILITY The AC and DC electrical power distribution subsystems !

required to be OPERABLE in MODES 4 and 5 and during movement i of irradiated fuel assemblies in the secondary containment I provide assurance that:

a. Systems to provide adequate coolant inventory makeup are available for the irradiated fuel in the core in '

case of an inadvertent draindown of the reactor vessel;

b. Systems needed to mitigate a fuel handling accident are available; (continued)

/

Brunswick Unit 2 B 3.8-88 Revision No. 7 i LA_-

. Distribution Systems-Shutdown B 3.8.8 BASES APPLICABILITY c. Systems necessary to mitigate the effects of (continued) events that can lead to core damage during shutdown are available; and

d. Instrumentation and control capability is available for monitoring and maintaining the unit in a cold shutdown condition or refueling condition.

The AC and DC electrical power distribution subsystem requirements for MODES 1, 2, and 3 are covered in LCO 3.8.7.

ACTIONS LC0 3.0.3 is not applicable while in MODE 4 or 5. However, since irradiated fuel assembly movement can occur in MODE 1, 2, or 3, the ACTIONS have been modified by a Note stating l that LC0 3.0.3 is not applicable. If moving irradiated fuel assemblies while in MODE 4 or 5, LCO 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, or 3, the fuel movement is independent of reactor

, operations. Entering LC0 3.0.3, while in MODE 1, 2, or 3, I

would require the unit to be shutdown, but would not require ,

immediate suspension of movement of irradiated fuel 1 assemblies. The Note to the ACTIONS, "LC0 3.0.3 is not applicable," ensures that the actions for immediate suspension of irradiated fuel assembly movement are not i postponed due to entry into LC0 3.0.3.

Ll. A.2.1. A.2.2. A.2.3 A.2.4. and A.2.5 Although redundant required features may require redundant divisions of electrical power distribution subsystems to be OPERABLE, one OPERABLE distribution subsystem division may be capable of supporting sufficient required features to allow continuation of CORE ALTERATIONS, fuel movement, and operations with a potential for draining the reactor vessel.

By allowing the option to declare required features associated with an inoperable distribution subsystem inoperable, appropriate restrictions are implemented in accordance with the affected distribution subsystem LC0's Required Actions. In many instances this option may involve undesired administrative efforts. Therefore, the allowance for sufficiently conservative actions is made, (i.e., to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies in the secondary containment, and any activities that could result in inadvertent draining of the reactor vessel).

,_ (continued) l Brunswick Unit 2 B 3.8-89 Revision No. 7 l

L 1 Distribution Systems-Shutdown B 3.8.8 BASES i ACTIONS A.1. A.2.1. A.2.2. A.2.3. A.2.4. and A.2.5 (continued)

Suspension of these activities shall not preclude completion !

of actions to establish a safe conservative condition.

These actions minimize the probability of the occurrence of postulated events. It is further required to immediately initiate action to restore the required AC and DC electrical i

power distribution subsystems and to continue this action until restoration is accomplished in order to provide the necessary power to the plant safety systems.

Notwithstanding performance of the above conservative Required Actions, a required residual heat removal-shutdown cooling (RHR-SDC) subsystem may be inoperable. In this I

case, Required Actions A.2.1 through A.2.4 do not adequately address the concerns relating to coolant circulation and i heat removal. Pursuant to LC0 3.0.6, the RHR-SDC ACTIONS ;

l would not be entered. Therefore, Required Action A.2.5 is '

provided to direct declaring RHR-SDC inoperable and not in operation, which results in taking the appropriate RHR-SDC ACTIONS. ,

The Completion Time of immediately is consistent with the ;

required times for actions requiring prompt attention. The !

restoration of the required distribution subsystems should !

be completed as quickly as possible in order to minimize the time the plant safety systems may be without power.

l l

SURVEILLANCE SR 3.8.8.1 '

REQUIREMENTS This Surveillance verifies that the AC and DC electrical power distribution subsystems are functioning properly, with the correct breaker alignment. The correct breaker alignment ensures power is available to each required bus.

The verification of energization of the buses ensures that the required power is readily available for motive as well as control functions for critical system loads connected to these buses. This may be performed by verification of the absence of low voltage alarms or by verifying a load powered from the bus is operating. The 7 day Frequency takes into

b. account the redundant capability of the electrical power H distribution subsystems, as well as other indications l available in the control room that alert the operator to

j. subsystem malfunctions.

l (continued) l l-l Brunswick Unit 2 B 3.8-90 Revision No. 7 1 l

L

),

Distribution Systems-Shutdown . d 4

B 3.8.8

- BASES (continued)

REFERENCES' 1.- .UFSAR, Chapter 6.

2. UFSAR, Chapter 15.

-3. 10 CFR 50.36(c)(2)(ii).

t

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i Brunswick Unit 2 B 3.8-91 Revision No. 7 I m.

ML20206R793

Text

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