ML19282A910
| ML19282A910 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/06/1979 |
| From: | Utley E CAROLINA POWER & LIGHT CO. |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| GD-79-612, NUDOCS 7903080306 | |
| Download: ML19282A910 (16) | |
Text
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Carolina Power & Light Company March 6, 1979 FILE: NG-3514 (B)
SERIAL:
GD-79-612 Office of Nuclear Reactor Regulation ATTENTION:
Mr. T. A. Ippolito, Chief Operating Reactors Branch No. 3 United States Nuclear Regulatory Commission Washington, D. C.
20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-325 AND 50-324 LICENSE NOS. DPR-71 AND DPR-62 ON-SITE EMERGENCY POWER SYSTDIS
Dear Mr. Ippolito:
Your letter of June 3, 1977, concerning on-site emergency power systems requested that Carolina Power & Light Company (CP&L) commit to plant modifications required to comply with the staff position outlined therein.
To supplement our partial response of July 28, 1977, we are enclosing as Attachment I a description of the degraded grid voltage modifications which we will complete during the current Brunswick Steam Electric Plant refueling outages.
Both outages are presently in progress.
In accordance with 10CFR50.90 and 10CFR2.101, we request that the operating licenses be amended to reflect the Technical Specification changes enclosed. These changes comply with the model technical specifica-tions supplied in Enclosure 2 of your June 3, 1977 letter insofar as possible. Any diffecences are explained in Attachment No. II.
7003080 3 o/,
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411 Fayetteville Street
- P. O. Box 1551
- Raleigh. N. C. 27602 mg.
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Since your June 3, 1977 letter required that we submit these technical specification changes, we have determined that an amendment application fee is not required.
Yours very truly, h
E. E. Utley Senior Vice President Power Supply TO!/DCS/DLB/j c Enclosures Sworn to and subscribed before tue tn!, 6th day of March, 1979 f?04flf/ti / /$, L b Notary Public N
My commission expires: July 4, 1980
Attachment I DESIGN BASIS DOCUMENT DEGRADED GRID VOLTAGE CAROLINA POWER 6 LIGilT COMPANY BRUNSWICK STEAM ELECTRIC PLANT UNITS 1 AND 2 DEGRADED VOLTAGE ON EMERCENCY BUS
Illl>E X Sc' tion Titic c
1.0 FUNCTION AND DES TC'I REQllif'!:!il:NTS 1.1 SYSTEl!IV CTION 1.1.1 Degraded voltage 1.1.2 Load Shedding 1.2 DESIGN REQUIRE!!ENTS 1.2.1 Performance 1.2.2 Codes, Standards, Reg. Cuides 1.2.3 Seismic Loads 1.2.4 Environmental Conditions 1.2.5 Electrient Requirements 1.2.6 Layout and Arrangement Requirements 1.2.7 Operational Requirements 1.2.8 Redundancy 1.2.9 Test Requirements 1.2.10 Inse rvice Inspection Requirements 1.2.11 Safety Cinus R1 1.2.'12 Quality Assurance 2.0 DESIGN DESCRIPTTON 2.1 DETAILED DESICil DESCRIPTION 2.1.1 Degraded Voltage 2.1.2 Load Shedding 2.2 SYSTE!! PERFORMANCE 2.3 COMPONENT DESIGN DESCRIPTION 3.0 EQUIPMENT SETPOINTS 4.0 APPENDICES 4.1 DRAUINGS 4.2 SPECIFICATIONS DllD-9527-041-1 INDEX s
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1.0 Pl!NCTIO:1 M;n DEsmi REo!ITnEttr.t:TS 1.1 SYSTEf! FU::CTin!1 1.1.1 Der raded voltane Provide a second Icvel of voltage protection to prevent a failure of safety related equipta nt due to degraded voltage and to minimize the ef fects of short duration disturhances from reducing the availability of the offsite power sources.
1.1.2 f.oad SheddInn
- Provide means to automatically prevent load shedding of the emergency buses once the Diesel Cencrators are supplying power to all sequenced loads on the c.mergency buses.
1.2 DESIG!! REQUIREMENTS 1.2.1 Performance The degraded voltage relays will monitor the voltage on the 4160 volt emergency buses through existing 4200 - 120 volt trip signal when voltage is below 89.57.
trans f orme rs and output a voltage for 10 seconds.
1.2.2 Codes, S t a nd a rd s, Reg. Cufdes The modifications shall satisfy the following requirements:
a.
IEEE 279-1971, " Criteria for Protection Svstems for Nuc1 car Power Cencrating Stations" b.
General Design Criterion 17 (CDC 17), "Elec t ric Powe r Sys tems",
of Appendix A, "Cencral Design Criteria f or Nuclear Power Plants" of 10 CFR Part 50 Nuclear Regulatory Commission " Safety Evaluation abd Statement c.
of Staff Positions Relative to the Emergency Power Systems for Ope ra ting Reactors" Position 1 and 2.
1.2.3 Seismfc f.oads Equipment must remain func t ional and operational during seismic events of 5.3 g's horfzontal front to hack combined with 1.0 g vertical and 2.0 g's horizontal afde to side combined with 1.0 g vertical.
1.2.4 Envfronmental Condition Temperature range 12"C to 40"C.
DBD-9527-041-1 Page 1 9
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1.2.5 Elect rical nequiremenen n.
Input Voltage Range:
0 - 160 volta ac b.
Input Frequency:
60 !!z c.
Control Power:
105 to 140 volts dc d.
Output Contact nati,ng:
10 amps tripping 5 amps continuous 1 nmp break-resistive 0.3 amp break-inductive c.
Drop-out Voltage:
987. of pickup voltage 1.2.6 Layout a ndle r.'n e,e me n t uequirements The degraded voltage protective relays shall be provided with a drawout type case and mounted on the door of the auxiliary potential transfonner compartment of each of the emergency switchgear buses.
The emergency switchncar buses are located at elevation 50'-0" in the Diesel Cenc ra tor 11uilding.
1.2.7 Ope ra t i onal ne ce i remen t t.,
1.2.7.1 Degraded Voltage The degraded voltage protective re ays will be calibrated to out put a trip signal to the incoming line breaker to the emergency hun whenever the voltage and time limits listed in Section 1.2.1 are exceeded.
1.2.7.2 Load Jhedding The operation of the exint ing undervoltage relay which initiates load uhedding chould be blocked when the Diesel Generator is supplying power to the sequenced loads on the emergency bus, 1.2.8 Redundancy Provide three degraded voltnge relays for each emergency bus and connect in a two out of t hree logic scheme.
1.2.9 Test Requirements Provide tent capability noch that degraded voltage relays can be calibrated and tented withaut removing sys tem from operation or blocking nhility of retnyn to perform their protective function.
ImD-9527-041-1 Page 2 gr--.
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1.2.10 Jnnervice In :r t ction Requiremeng The Technical Specification requirements will be no listed in liodel Technical Specification Table 4.3-2, LOSS OF POWER, Part b.
1.2.11 Snfety clans R1 The equipment necessary for the Degraded Voltage modification is Class IE.
R1 1.2.12 gun 11 tv Annurance a.
Desinn Orp,anizarion The design and procurement of safety-related items shall be donc under a QA program and implementing procedures which meet the requirements of 10CFlt',0, Appendix 11, and the regulatory guides and ANSI st.indards referenced in WASil 1283, Revision 1, " Guidance on Quality Assurance Requirements During Desinn and Procurement Phase of Nuclear Power Plants" and the appilcable portions of WASil 1309, "Cuidance on Quality Assurance Requirements During the Construction Phase of Nucicar Power Plants".
b.
Construction The construction and procurement of safety-related items shall be done under n QA program and implementing procedures which racet the requirements of 10CFR50, Appendix B, and the regulatory guides and ANSI standards referenced in.WASil 1309, "Cuidance on Quality Assurance Requirements During Construction Phase of Nuclear Power Plants" as conuni t ted to by CP&L's le t te rs to NRC NC-75-300 dated February 27, 1975, and !!C-75-1278 dated August 26, 1975.
DBD-9527-041-1 Page 3 r~7"
. ' 2.0. DESIGN DESCR T PTIO!!
2.1 DETATT.UD DESIC;1 DESCRIP'1 TO!!
2.1.1 Denraded vol tane Th ree ITE-27D de finite time undervoltage relays -(27) are connected in a two out of three logic scheme for each of the four 4160 volt emergency huses.
(Total of twelve (12) relays.)
'lhe unde rvol tage relay coils are connected to the exis ting potent ial trans formers in each bus with one relay on each pF we.
A Westinghouse Electric Co. Style No. 837A101C01 test switch,TS) is connected to each relay to permit relay testing.
A contact from an Anastat time-delay on d rop-out relay (2) adjustabic from 0.5 to 5 seccuds is wired in series with the undervoltage relay contacts to prevent tripping of the breaker when the bus is initially energized.
The time-delay relay is ene rgized by a "b"
contact f rom the incoming line breaker.
The contacts of the undervoltage relay energize an existing auxiliary relay (94) which trips the incoming line breaker to the emergency bus and the feeder breaker f rom the BOP switchgear to the emergency bus.
See drawing SK 71377 for the schematic of the Degraded voltage Circuitry.
2.1.2 Load Shedding A
"b" auxiliary contact of the diesel generator breaker is added in series with the existing undervol'tage auxiliary relays which initiate load shedding on the emergency bus.
This contact will be open when generator breaker is closed and hence will block operation of the undervoltage auxiliary relays.
2.2 SYSTEM PERFORMANCE The undervoltage relay will be set to output a trip signal when the 4160 V emergency bus voltage is below 89.57. voltage for 10 seconds.
2.3 COMPONENT DESTCN DESCRTPTIO!!
The ITE-27D definite time undervoltage relay has the following design characteristics.
n.
Input Voltage Rating:
160 volts ac b.
Frequency:
Frequency compennated between 20 and 400 Hz.
Rated Frequency 50/60 llZ c.
Rated Control Power:
125 volts de D110-95 27 -041-1 Page 4
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d.
Output Contact Rating:
10 amps tripping 5 ntnps continuous 1 nmp break-resistive 0.3 amp break-inductive c.
Drop-out Voltage:
987. of pickup voltage o
o f'. 'Tempe ra ture Range :
-20 C to +75 C g.
Scis.iic Capability:
6 g's ZPA, 15 g's peak between 4 and 16 IIz 4
O e
e DllD-952 7-041-1 Page 5 O
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3.0 E0llIPMEf4T SETPOINTS a.
Undervoltage Relay Drop-out Voltage Calibration:
106.5 volts 0.25 yolts b.
Undervoltage Itclay Time Calibration:
10 occonds 0.5 seconds c.
Time Delay Drop-out Relay Calibration:
_2 seconds I 0.5 ceconds Dill)-9 52 7-041-1 Par,e 6 t
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~4.0 APPENDICES 4.1 DRAllillCS D_rnuinn No.
Rev.
Date Titic SK 71377 1
11/23/77 Degraded Voltage Circuitry 4.2 SPECIFICATIONS Speci ficaric -
2 Rev.
Date Title R1 9527-01-14'-9 1
2/13/78 Degraded Vol tage Protective Relays e
DBD-9527-041-1 Page 7 ao W
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Attachment Il DISCUSSION OF CilANCES TO TECllNICAL SPECIFICATIONS The following paragraphs discuss the difference between the NRC model technical specifications and the Brunswick Steam Electric Plant proposed technical specifications.
At the Brunswick Steam Electric Plant, there is only one loss of voltage relay per electrical distribution bus.
There are presently no instru-ment check surveillance requirements in technical specifications for these loss of voltage relays. These relays are not analog readout devices whose measure-ments can be compared with other instruments.
These relays are continuously energized and will fail in the tripped condition which would be alarmed in the control room.
For these reasons, a channel check and a channel functional test surveillance requirement is not required.
Under NRC model surveillance requirement 4.8.1.1.X, it is assumed that Itens a.l. (a), a.l. (b), and a.l. (c) are to be performed in sequence.
If this is the case, Brunswick cannot perform the intent of this test (i.e., Item a.l.(c))
because, in this case, the only trips of a BSEP diesel would lock out the diesel from restart.
These lockout trips are trips that are caused by events which could cause irreparable damage to the diesel generators (see Brunswick surveillance re-quirement 4.8.1.1.2.d.4.).
These lockout trips can be reset following rectification of the condition that led to the trip.
Because of the design of the Brunswick load shed blocking featurcs, if,following lockout reset, the conditions that required an automatic statt of the diesel still exist, then the diesel will restart and loads will resequence onto the bus using the same logic that was used during the initial start.
Because of this design feature, the requirement for surveillance require-ment 4.8.1.1.X.a.1. (c) is redundant and not necessary, and thus has not been proposed as a Brunswick technical specification.
W
TABLE 3.8-1 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION MINIMUM TOTAL NO.
CHANNELS CHANNELS APPLICABLE FUNCTIONAL UNIT OF CHANNELS TO TRIP OPERABLE OPERATING MODES
- ACTION LOSS OF POWER a.
4.16 kv Emergency Bus Undervoltage (Loss of Voltage) 1/ Bus 1/ Bus 1/ Bus 1,2,3 A
b.
4.16 kv Emergency Bus Undervoltage (Degraded Voltage) 3/ Bus 2/ Bus 2/ Bus 1, 2, 3 B
co A
TABLE 3.8-1 ACTION STATEtlENTS ACTION A - With no operable channels, the essociat. d diesel generator will be considered inoperable and con-ditions 3.8.1.1 will apply.
ACTION B - With the number of OPERABLE Channels one less than the Total Number of Channels, operation may proceed until performance of the next required CIIANNEL FUNCTIONAL TEST provided the inoperable channel is placed in the tripped condition within I hour.
3/4 8-13
TABLE 3.8-2 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION TRIP VALUES FUNCTIONAL UNIT TRIP VALUE ALLOWABLE VALUES LOSS OF POWER a.
4.16 kv Emergency Bus Undervoltage 4.16 kv Basis - 2940 161 volts $10 sec 2940 1 315 volts $10 sec (Loss of Voltage)*
120 v Basis - 84 1 4.6 volts time delay 84 1 9 volts time delay b.
4.16 kv Emergency Bus Undervoltage 4.16 kv Basis - 3727 9 volts 1010.5 sec 3727 1 21 volts 1011.0 see (Degraded Voltage) 120 v Basis - 106.510.25 volts time delay 106.510.60 volts time delay M
w Y
5
- This is an inverse time delay voltage relay. The voltages shown are the maximum that will not result in a trip. Lower voltage conditions will result in decreased trip times.
i I
TABLE 4.8-1 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS OPERATING CHANNEL MODES IN WHICH CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE FUNCTIONAL UNIT CHECK CALIBRATION TEST REQUIRED LOSS OF POWER a.
4.16 kv Emergency Bus Undervoltage (Loss of R
1, 2, 3 Voltage) b.
4.16 kv Emergency Bus Undervoltage (Degraded S
R M
1,2,3 Voltage)
M P
G S = at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> R = at least once per 350 days M = at Icast once per 31 days
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