ML19308B197
| ML19308B197 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/03/1977 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19308B196 | List: |
| References | |
| NUDOCS 7912160054 | |
| Download: ML19308B197 (17) | |
Text
_ _ _ _
p3 EfC UNITED STATES jf,
NUCLEAR REGULATORY COMMISSION 3.j(f'T)/ j y*g W ASHINGTON, 0. C. 20555
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November 3, 1977
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Cocket Nos. 50-269 50-270 and 50-287 Duke Power Company ATTN:
Mr. William 0. Parker, Jr.
I Vice President - Steam Production Post Office Box 2178 422 South Church Street Charlotte, North Carolina 28242 Gentlemen:
The Comission has issued the enclosed Amendment tios. 50, 50 and 47 for License Nos. DPR-38, DPR-47 and DPR-55 for Oconee Nuclear Station, Unit Nos. 1, 2 and 3, respectively.
These amendments consist of changes to the Station's common Technical Specifications and are in response to your request dated October 13, 1976, as supplemented Septenter 29, 1977.
These amendments revise the Technical Specifications to allow operation of the Oconee Nucl'ar Station, (1) with one Keowee hydro unit out of service for periods not to exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or operation with the under-ground feeder out of service for periods not to exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; (2) with one Keowee hydro unit out of service from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> up to a maximum of 45 days when the remaining Keowee unit and both the overhead and underground transmission circuits are operable and the standby buses are energized by one of the two Lee gas turbines; and (3) with both Keowee hydro units out of service for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for planned reasons or 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for unplanned reasons.
Revisions are also made to surveillance requirements of the En gency Power System.
Copies of our Safety Evaluation and Notice of Issuance are also enclosed.
Sincerely,
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'- A. Schwencer, Chief Operating Reactors Branch #1 L*ivision of Operating Reactors Enclosures and cc:
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!- - November. 3,1977 Duke Power Company;
Enclosures:
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1.
Amendaent No. 50 to OPR-38 2.
Amendment No. 50 to DPR-47 3.
Amendment No. 47 to DPR-55
- 4.
Safety Evaluation 5.
Notice cc w/ enc 1:
Mr. William L. Porter Duke Power _ Company Post Office Box 2178 1
422 South Church Street Charlotte, North Carolina 28242 J. Michael McGarry, III, Esquire
- DeBecoise & Liberman i
700 Shorcham Building 806 - 15th Street, NW j
Washington, D.C.
20005 l
Oconee County Library l
201 South Spring Street Walhalla, South Carolina 29691 Office of Intergovernmental Relations i
116 West Jones Street Raleigh, North Carolina 27603 i
i Chief, Energy Systems i
Analyses Branch ~(AW-459)
Office cf Radiation Programs-U.S. Environmental Protection Agency Room 645, East Tower 401 M Street, SW liashington, D.C.
20460 l
U.S. Environmental ~ Protection Agency i
Region IV Office L
ATTN:
EIS COORDINATOR f
345'Courtland Street, NE l
Atlanta,' Georgia 30308 l
' Honorable James M. Phinney-County Supervisor of-Cconee County I
-Walhalla, South Carolina' 29621 I
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UNITED STATE'S
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DUKE POWER COMPANY DOCKET NO. 50 269 OCONEE NUCLEAR STATION, UNIT N0.1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 50 License No. OPR-38 4
1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendments by Duke Power Company (the licensee) dated October 13, 1976, as supplemented S~eptember 29, 1977, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rule s and regulations of the C ommission; C.
There is reasonable assurance (i) that the activities authorized 4
by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; l
D.
The issuance of this amendment will not be inimical to the j'
corInon defense and security or to the health and safety of the public; and E.
The ' issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is. amended by a change to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 3.B of Facility License No. DPR-?3
'is hereby amended to read.as follows:
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. "3.B Technical Specifications 4
The Technical Specifications contained in Appendices
- A and B, as revised through Amendment No. SO, are hereby incorporated in the license.
The licensee shall' u,'erate the facility in accordance with the Technical Spe ifications."
3.
This license amendment is effective within 30 days after the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION i
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~ A. Schwencer, Chief i
Ooerating Reactors Branch #1 i
Division of Operating Reactors
Attachment:
Changes to the Technical i
Specifications Date of Issuance:
November 3, 1977 l
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,e UNITED STATES j
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NUCLEAR REGULATORY COMMISSION a
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/, f W ASillNG TON. D. C. 20355 t gas. / 4 nf DUKE POWER COMPANY DOCKET N0. 50-270 OCONEE NUCLEAR STATION, UNIT N0. 2 AMENDMENT TO FACILITY OPERATln? LICENSE Amendment No.50 License No. DPR 47 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendments by Duke Power Company (the licensee) dated October 13, 1976, as supplemented S~eptember 29, 1977, complies with the standards and requirements of the Atomic Energy Act of 1954,.as amended (the Act), and the Comission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in ccapliance with the Commission's regulations; D.
The issuance of this amendment vill not be inimical to the conrnen defense and security or a the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is amended by a change to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 3.B of Facility License No. DPR-47 is hereby amended to read as follows:
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"3.B Technical Specifications The Technical Specification'. contained in Appe'ndices A and B, as revised thr Jgh Amendment No. 50, are hereby incorporated in the license.
The licensee shall operate the facility in accordance with the Technical Specifications."
3.
This license amendment is effective within 30 days after the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION s
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- ' t ? :.'L..'!.Oh A. Schwenct.", Chief Operating Reactors Branch #1 Division of Operating Reactors
Attachment:
Changes to the Technical Specifications Date of Issuance:
November 3, 1977 1
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UNIT ED STATES NUCLEAR REGULATORY COMMisslON y Q,
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DU_KE POWER COMPANY DOCKET NO. 50-287 OCCNEE NUCLEAR STATION, UNIT NO. 3 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 47 License No. OPR-55 1.
The Nuclear Regulatory Conmission (the Commission) has found that:
A.
The application for amendments by Duke Power Comoany (the licensee) dated October 13, 1976, as supplemented S~eptember 29, 1977, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rule s and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.
The issuance of this amendment will not be inimical to the coranon defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is amended by a change to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 3.B of Facility License No. DPR-55 is hereby amended to read as.follows:
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"3.B Te_chn_ical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 47, are hereby incorporated in the license.
The licensee shall operate the facility in accordance with the Technical Specifications."
3.
This license amendment is effective.within 30 days after the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
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A. Schwencer, Chief Operating Reactors Branch =1 Division of Operating Reactors
Attachment:
Changes to the Technical Specifications Date of Issuance:
November 3, 1977 N
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ATTACHMENT TO LICEtlSE AMENDMEhTS AMENDMENT NO. 50 TO~ DPR-38
. AMENDMENT NO. 50 TO DPR-47 e
AMENDMENi N0. 47 TO' DPR-55 DOCKET NOS. 50-269, 50-270 AND 50-287 l
l Revise Appendix A as follows:
Remove Pages Insert Pages 3.7-2 3.7-2 3.7-3 3.7-3 3.7-4 3.7-4 3.7-5 3.7-5 3.7-6 3.7-6 3.7-7 3.7-7 3.7-8 3.7-8
.3.7-9 4.6-1 4.6-1 4.6-2 4.6-2 i
. Add page 4.6-3 I
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(1)
The Keowee batteries with their respective chargers, buses and isolating diodes shall be operable.
(j )
The level of the Keowee Reservoir shall be at least 775 feet above sea level.
3.7.2 During het standby or power operation, provisions of 3.7.1 =ay be modified to allow any one of the following conditions to exist:
(a)
One of the two required startup transformers may be' removed from service for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> provided it is expected to be restored to service within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> and the other required startup trans-former is available for automatic connection to the unit's =ain feeder bus.
(b)
One Keowee hydro unit may be inoperable for periods not ex-ceeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for tes er maintenance provided the operable Keewee hydro uni: d.s connected to the underground feeder circuit and is verified operable within one hour of the loss and every eight hours thereafter.
(c)
The underground feeder circuit may be inoperable for periods not exceeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for tes: and maintenance.
(d) in each unit, the following items may be inoperable for periods not exceeding 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:
1.
One 4160 vol: =ain feeder bus.
2.
One complete single string of any unit's Engineered Safety Features 4160 volt switchgear bus, 600 volt load center -
600V-20SV MCC and their loads.
3.
One ce=plete single 12 ring of any unit's 125 VDC instru-
=entation and centrol batteries, chargers, buses, and all associated isolating and transfer diodes.
4 One 125 VDC instrumentation and control panel board and/or its associated loads.
(e)
One complete single string of the 125 VDC switching station bat:eries, buses, chargers, and the related diode assemblics i
cay be de-energiced for test or maintenance for periods no:
l exceeding 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
t (f)
One complete single string of the Keovee batteries, chargers, buses, and isolating diodes may.be de-energiced for test or
=aintenance for periors not exceeding 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
3.7-2 Amendr.cn ts 50, 50 & 47
/
(g)
One 4160 volt standby bus may be inoperable for test or maintenance for periods not exceeding 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
3.7.3 In the event tha: the conditions of Specification 3.7.1 are no:
met within the ti=e specified in Specification 3.7.2, except as noted below in Specification 3.7.4, 3.7.5, 3.7.6, and 3.7.7 the reac:er shall be placed in a hot shutdown condition within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
If these requirements are no: =et within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the reactor shall be placed in the cold shu:down condi-tion within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
3.7.4 In the event that all conditions in Specification 3.7.1 are met except that one of the two Keowee hydro units is expected to be unavailable for lenger than the tes or main:enance period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, the reactor =ay be heated above 2000F if previously shutdown or be permitted to remain critical or be restarted provided the following restrictions are observed.
(a)
Prior to heating the reactor above 20007 or prior to the of a shutdown reactor or within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the restar:
loss of one Keowee hydro unit, the 4160 volt s:andby buses shall be energiced by a Lee gas turbine through the 100 kV circuit. The Lee gas turbine and 100 kV transmission circuit shall be electrically separate fro the sys:e= grid and non-safety-related loads.
(b) The re=aining Keowee hydro unit shall be connected to the underground feeder circuit and this path shall be verified operable within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and weekly thereafter.
(c)
The remaining Keowee hydro unit shall be available to the overhead transmission circuit but generation to the system grid shall be prohibited except for periods of test.
(d)
Operation in this mode is restricted to periods not to exceed 45 days and the provisions of this specification may be utiliced without prior NRC apprcval only once in three years for each Keowee hydro unit.
Office of Inspection and En-force =ent, Region II, vill be notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
3.7.5 In the even tha: all condi: ions of Specifica: ion 3.7.1 are met excep: that all 230 kV trans=ission lines are lost, the reactor shall be permitted to remain critical or be restarted provided the following restrictions are observed:
(a)
Prior to the restart of a shutdown reactor or within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of losing all 230 kV transmission lines for an operating reactor, the 4160 volt standby buses shall be energized by one of the *_ee gas turbines through the 100 kV transmission circuit.
The Lee gas turbine and the 100 kV transmission circui: shall be completely separate from the system grid and non-safe:y-related loads.
3.7-3 Amendments 50, 50 & 47
The reactor coolant Tavg shall be above 525'F.
Reactor coolant (b) pump power may be used to elevate the temperature from 500 F to 525 in the case of restart.
If T decreases below 500*F, restart av8 is not permitted by this specification.
least one of (c)
If al] 230 kV transmission lines are lost, restore at the inoperable 230 kV offsite sources to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
two 230 kV With only one offsite source restored, restore at least offsite circuits to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from time of initial loss or be in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
After loss of all 230 kV transmission lines, this information shall (d).be reported within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to the Office of Inspection and Enforce-
- ment,
, Region II.
If the outage is expected to exceed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />,
a written report shall be submitted detailing the circumstances of the outage and the estimated time to return the 230 kV transmission lines to operating condition.
and In the event that all conditions of Specification 3.7.1 are met, 3.7.6 ple.med tests or maintenance is required which will make both Keowee units unavailable, the 4160 volt standby buses shall first be energi:ed by a Lee gas turbine through the 100 kV transmission circuit and shall The reactor be separate from the system grid and non-safety-related loads.
to exceed 72 shall then be permitted to rcrain critical for periods not hours with both Ecowee units unavailabic.
restart of a reactor from a tripped condition, the causes
, Prior to hot of the shutdown shall be established and analy:cd. A and the effectn restart will be permitted if the cause of such trips are the result of error or of minor equipment malfunctions. A restart will not be permitted if the trip is a result of system transients or valid protection system action.
3.7,7 In the event that all conditions of Specification 3.7.1 are met except that both Keowee hydro units become unavailabic for unplanned reasons, to exceed the reactor shall be permitted to remain critical for periods not 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided the 4160 volt standby buses are energi:ed within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by the Lee gas turbine through the 100 kV transmission circuit and it shall be separate. from the system grid and all offsite non safety-related Icads.
Prior to hot restart of a reactor from a tripped condition, the causes and the effects of the shutdown shall be established and analy:cd.
A restart will be permitted if the cause of such trips are the result of A restart will not be permitted error or of minor equipment malfunctions.
if the trip is a result of system transients or valid protection system action.
Any degradation belond Specification 3.7.2, 3.7.4, 3.7.5, 3.7.6 or 3.7.7 3.7.8 above shall be reported to the Office of Inspection and Enforeccent, Region l
II, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
A safety evaluation shallbe performed by Duke Power Company for the specific t ituation ' involved which justifies the safest course of act ion to -he taken.
The results of this evaluation together with plans for c3pedit ing the return to the unrestricted operating conditions of Specificat ion 3.7.1 above shall be submitted in a written report to the Office of Nuc! car Reactor llegulation with a copy to the Office of Inspection and Enforcement,. Region II, within five days.
Amendments 50, 50 &'47 3.7-4
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The auniliary clectrical pcuer systems are designed to supply the required h
-Engincered Safeguards Icads in ene unit and safe shu:dcen loa These systems were engineered saf ety f eatures to jeopardi:e plant saf e:y.
designed to =cet the following criteria:
" Alternate power syr: ems shall be provided and de-igned with indcpendency, redundancy, capaci:y and testability adequatc I
to permit tae functione required of the engineered safe:y
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features of each unit."
4 The auxiliary power sys:c= meets the above criteria and the intent of AIC-Criterion 17.
The adequacies of the AC and DC systems are discussed below as are the bases for permitting degraded conditions for AC power.
i Capacity of AC Svs:ers t
The auxt:iaries of :Vo ur.its in hot shutdown (6.CMVa each) plus the auxiliaries activated by F.SG signal in the other uni: (4.8 MVa) require a total AC power capacity of 16.8 MVa.
The continuous AC power capacity available fr== the on-site power sys:cmr (Keovee Hydre Units) is 20 MVa (limited by transformer CT4) if furnished by the undcrr.round circuit or 30 MVc (limited bv CT1 or CT2) if furnished through the 230 kV off-site trans=ission lines.
Capacity available frc= the ba:kup 100 kV off-site transmission line (Lee Station Gas Turbine Genera:cr) is 20 ':Va (li=ited by CTS).
j i
Thus, the mini =ut availabic capacity from any ene of the cultiple sources of AC power, 20 MYa, is adequatc.
C..c :m ci t y of DC Systems AC power is rectified and supplies the DC rystem Nornally, f or each uni:
buses ar. well as keeping the storage ba::eries on these buses in a charged Upon loss of this nor=al AC source of power, each unit's DC auxiliary state.
to reactor saf ety have adequa:e stored capacity (ampere-systems important leas:
hours) to independently supply their required emergency loads for at Orc hour is considered te be conserva:ive since there are redundant ene hour.
sourcer. of A( power previdinp enerr,v to these DC auxiliarv systers.
The loss of all AC pov - t o.iny IC svstem 1:, expee:ed to occur verv infrequently, and the period 3 r,f tine.
The followint, tabulation demonstrates
- 1 er very t.ho: :talled batt e.cy charger rating and battery capacity when ec= pared margin of in:
with AC power (in a:ps) and (b) without A2 pever to one hour of epcratica fa) fer each of the :hree safety-rela:ed DC systems installed (in a pere hours) at Oconee:
125 VDC instrumentation and Control Pever Syste A.
a.
600 amps each
).CA. Xct. er XCS l
. Char b.
698 a= pere-hourt Battet, }C/ and ICL Cenbined C:pacity (X - 1, 2, or 3)
First min. - 1371 amps a.
Actual active londs en both 125 VD -
59 min. - 568.'5 anps nex:
I & C buses XDCA and XDC3 b.
581.9 aspere-hours i
during ist hour of LOCA (X = 1, 2, or 3) 3.
125 VDC Switchin;. Station Pcwer System 50 amps each-Charger SY-1,. S'i-2, or SY-s Ra ing a.
b.
14.4 ampere-hours Battery SY-1 or SY-2 Capacity 3.7-I Amendments 50, 50 4 47 L
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Firs: =in. - 130 a=ps Actual active load per battery nex: 59 mi 4.
- 10 a=ps during ist hour of LOCA b.
12 a= pere-hours C.
125 VDC Eeowee Station Power Sys:c=
Charger No. 1, No. 2 or Standby Rating a.
200 a=ps each b.
233 ampere-hours Battery No. 1 or No. 2 Capacity a.
Firs: =in. - 1031 a=ps Actual active load per battery nex: 59 min. - 179.4 a=ps during is: hour of LOCA b.
193.6 a= pere-hours Redundanev of AC Systens There are three 4163 engineered safe:y feature svitchgear buses per unit.
Each bus can receive power fro = either of the two 4160 =ain feeder buses per Each fer.er bus in turn can receive power from the 230 kV swi:chyard unit.
through the s:crtup transfor=ers, through the uni: auxiliary transfor=er by backfeeding through the =ain step-up transformer, or frc= the 4160V s:andby Another unit's c:artup transforcer serving as an alternate supply can bus.
be placed in service in ene hour.
The standby bus can receive power fro = the Hydro Station throu;h the underground feeder circuit o-fro = a combustion the Lee S:ea= Station over an isolated 100 kV trans-turbine generator a:
mission line.
The 230 kV switchyard can receive power from the on-si:e Keowee Hydro s:ation er fro: several off-site sources via transmission lines
- he Ocenee S:ation with the Duke Power syste= power distribution which connect network.
Redundancy of DC Syste=s A.
125 VDC Instrument and Control Power Syste:
All reactor protection and engineered safety features leads on this sys:e= can be powered f rom either the Unit 1 and Unit 2 or Unit 2 and Unit 3 or Unit 3 and Unit 1 125 VDC Instrumen and Control Pever Suses.
The units ' 125 VD^ Instru=ent and Control Power Suses can be powered fro:
two battery banks and three battery chargers.
As shown above, one ba::ery (e.g., ICA) can supply all loads for one hour.
Also, cae battery charger can supply all connected ESF and reactor protecticn loads.
3.
125 VDC Switching Sta: ion Power Syste=
There are two essentially independent subsystees each co=plete wi:h an AC/DC power supply (battery charger), a ba:tery bank, a ta::ery charger bus, noter centrol center (distributien panel).
All safety-related eq uip=ent and the relay house in which it is located are Class I (seismic) design.
Each subsysten provides the necessary DC power ~;o:
Continuously monitor operations of the protective relaying.
a.
Isolate Oconee (including Keowee) fro = all external 230 kV grid b.
J faul:s, 3.7-6 Amendments 50, 50 & 47 I
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Connect on-site power to Oconee fro: a Keowee hydro unit or, c.
d.
Restore off-site pcwer to Oconee fro: non-faulted portions of the extcrnal 230 kV grid.
Proviciens are includec to manually connect a standby battery charger to either battery / charger bus.
C.
125 VDC Keowee Station Power Syste=
There are essentially two independent physically separated Class !
(seismic) subsystees, cach co=ple:e with an AC/DC power supply (charger)
Each l
a battery bank, a bat:cr":/ charger bus and a DC distribution center.
subsysten provides the necessary power to automatically or manually start, a
control and protect one of the hydro units.
An open er sher: in any one battery, charger of DC distribution center, canno: cause loss of be:h hydro units.
The 230 KV sources, while expected to.have excellent availability, are not under the direct con:rol of the Oconee station and, based on past experience, cannot be assu=ed :c be available a: all ti=es.
However, the opera:1cn of
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the on-site hydre-station is under the direct con:rol of the Oconee Station and requires no off-site power to startup.
Therefore, an on-site backup source of auxiliary power is provided in the for: ef twin hydre-electric turbine generators pcwered through a ec==en penstock by water taken from Lake Keowee.
The use of a cenmon pens:och is justified on the basis of pas: hydro plan:
experience of the Duke Power Ce:pany (since 1919) which indicates tha: the cu=ulative need to dewater the penstock can be expected to be limited to about one day a year, principally for inspection, plus perhaps fcur days every tenth year.
Operation with one Keowee Hydro unit.out of servi _e fer periods less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is per=it:cd. The operability of the re=aining Keowee hydro unit is verified within one hour by star:ing the uni: and energizing the standby buses through the underground feeder circuit.
This action is repeated once every eight hours thereafter until the Keowee hydro unit is res:ored to service and vill provide additional assurance of the operability of the remaining unit.
Provisions have been established fer those conditions in which long ter=
preventative maintenance of a Keovee Hydro unit are necessary.
The primary long ter: =aintenance items are expected to be hydro turbine runner and dis-
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charge ring velding repairs which are esti=ared':c be necessary every six to eight years.
Alsc, generater thrust and guide bearing replacements'will be necessary.
Other itens which manifest as failures are expe: ed to be ex-tremely rar e and could pessibly be performed during the permitted maintenance periods.
Time periods of up to 45 days for each Keowee Hydro unit are permitted every three ycars. During these outages the re=aining Keowee Hydro unit vill be verified :: be operable wi:hin one hour and weekly thereaf ter by s:crting the unit and energicing the underground feeder circuit.
The re=ainin; Keowee
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hydro. unit will also be available through the overhead transmission pa:h-and will not be used for ryste= peaking.
Additionally, the standby buses will be energized centinucusly by one of the Lee gas turbines through the 100 kV rans-ciscion circuits 3.7-7 Anendments 50, 50-& 47
o.
This transmission circuit would be electrically separated from the system grid and all off-site non-safety-related loads.
This arrangement provides a high degree of reliability f or the emergency power systems.
Operation with both Keowee Hydro units'out of-service is permitted for planned
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or unplanned outages for periods of 72 or 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> respectively.
Planned outages are necessary for the inspection of co= mon underwater areas such as the pensteck and to enable the ree: val of one Keowee unit from service.
This would be a con: rolled evolution in which the availability and condition of the off-site grid, startup transforects and weather would be evaluated and a Lee gas turbine would be placed in opera: ion on the isolated 100 kV trans=ission line prior c co=mencecent of the outage.
A time period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for unplanned outages of both Keowee units is ac apt-able since a Lee gas turbine will be started within one hour and will energize the standby buses through the dedicated 100 kV trans=issien line.
This period of time is reasonable te deter =ine and ree:1fy the situa:1on which caused the loss of both Keowee units.
In the event that none of the sources of off-site power _are available and it is considered important to c atinue to maintain an Oconee reactor critical or re-turn it to criticality frc= a hot shutdown condition, one of the Lee gas turbines
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can be made avcilable as an additional backup source of power, thus assuring continued availabill:y as an auxiliary power to perform an orderly shutdown of a unit should a probic: develop requiring shutdown of both hydro uni:s.
i 3
4 i
k i
. 8 Amendnents 50, 50 & 47 t.
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