ML20086U305
| ML20086U305 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 07/28/1995 |
| From: | Stetz J CENTERIOR ENERGY |
| To: | |
| Shared Package | |
| ML20086U304 | List: |
| References | |
| NUDOCS 9508040045 | |
| Download: ML20086U305 (17) | |
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~Dockat Nuzbar 50-346
.Licenn Nuxb2r NPF-3 l Serial Number 2305 Enclo'sure
'Page 1 )
i APPLICATION FOR AMENDMENT ;
TO FACILITY OPERATING LICENSE NUMBER NPF-3 DAVIS-BESSE NUCLEAR POWER STATION UNIT NUMBER 1 i
Attached is the requested change to the Davis-Besse Nuclear Power Station, Unit Number 1, Facility Operating License Number NPF-3. Also included is the Safety Assessment and Significant Hazards Consideration.
The proposed change (submitted under cover letter Serial Number 2305) concerns Appendix A, Technical Specification 3/4.8.1.1 - A.C. Sources - Operating, Technical Specification 3/4.8.1.2 - A.C. Sources - Shutdown, and their Associated Bases, and Bases 3.0.5.
l By:
John P.'Stetz, Vice' President - Nuclear Sworn to and subscribed before me this 28th day of July, 1995.
k W m b uJ Y 1/6 Notary Public, Statef'of Ohio '
EVELYN L DRESS Ofotory Putdic State of Ohio My Commiseson Empwes 7/28/98 i
h 9508040045 950729 PDR ADOCK 05000346 P- PDR
1 Dock 2t Nu;bar 50-346 Lic nzo Nunbar NPF-3 ;
Serial Number 2305 l Enclo'sure
'Page 2 The following information is provided to support issuance of the requested ,
changes to the Davis-Besse Nuclear Power Station (DBNPS), Unit Number 1, Facility Operating License Number NPF-3, Appendix A, Technical Specifica-tions. The changes involve Technical Specification 3/4.8.1.1 - A.C. Sour-ces - Operating, Technical Specification 3/4.8.1.2 - A.C. Sources - i Shutdown, and their associated Bases, and Bases 3.0.5.
A. Time Required to Implement: This change is to be implemented within 90 !
days after the NRC issuance of the License Amendment.
B. Reason for Change (License Amendment Request Number 95-0004):
This application proposes the following revisions: clarify the Limiting Condition for Operation for TS 3.8.1.1 and 3.8.1.2 from " independent" circuit to " qualified" circuit; explain in the Bases the requirements for operability of an offsite circuit; delete the STAGGERED TEST BASIS scheduling requirement to perform Emergency Diesel Generator surveil-lances; explain in the Bases an acceptable method for verification of Emergency Diesel Generator speed for surveillance requirements (SR) 4.8.1.1.2.a.4 and 4.8.1.1.2.c.4; remove a surveillance test extension that has expired for SR 4.8.1.1.1.b; and add an exception for SR 4.8.1.1.2.c.5 and 4.8.1.1.2.c.7 to SR 4.8.1.2. A revision is also proposed to Bases 3.0.5 to reflect the clarification from " independent" circuit to " qualified" circuit.
These changes are being proposed to clarify the requirements for operability of an offsite circuit, provide flexibility in the schedul- '
ing and performance of Emergency Diesel Generator surveillance tests, conform the Technical Specification surveillance requirements with ex- i isting exceptions, explain surveillance test methods in the Bases and make administrative changes to the Technical Specifications and Bases.
C. Safety Assessment and Significant Hazards Consideration: See Attachment f
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Dockat Nurber 50-346 Lic nts Nu;b r NPF-3 Serial Number 2305 Attachment 1 SAFETY ASSESSMENT AND SIGNIFICANT HAZARDS CONSIDERATION FOR LICENSE AMENDMENT REQUEST NO. 95-0004 (22 pages follov) l l
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LAR 95-0004 P Peg 2 l' ;
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b i s
SAFETY ASSESSMENT AND SIGNIFICANT -
HAZARDS CONSIDERATION. :
FOR _
LICENSE-AMENDMENT REQUEST NO. 95-0004 TITLE:
' Proposed Modification to the Davis-Besse Nuclear Power Station (DBNPS).
Unit Number 1, Facility Operating License NPF-3, Appendix A Technical Spec- ;
ifications to Revise Technical Specifications 3/4.8.1.1 - A.C. Sources - !
Operating, 3/4.8.1.2 - A.C. Sources - Shutdown, and their Associated Bases, ;
and Bases 3.0.5. ,
DESCRIPTION: ,
?
The proposed revisions modify the Davis-Besse Nuclear Power Station (DBNPS), Operating License NPF-3, Appendix A Technical Specifications-(TS) 3/4.8.1.1 - A.C. Sources - Operating, TS 3/4.8.1.2 - A.C. Sources -
Shutdown, and their associated Bases, and Bases 3.0.5.. ,
3 The proposed revisions: clarify the Limiting Condition for Operation (LCO) for TS 3.8.1.1 and 3.8.1.2 from " independent" circuit to " qualified" ;
circuit; explain in the Bases the requirements for operability of an off- !
site circuit; delete the STAGGERED TEST BASIS scheduling requirement to perform Emergency Diesel Generator sutveillances; explain in the Bases, an acceptable method for verification of Emergency Diesel Generator speed for surveillance requirements (SR) 4.8.1.1.2.c. 4 and 4.8.1.1.2.c.4; remove a ;
surveillance test extension that has expired for SR 4.8.1.1.1.b; and add an l exception for SR 4.8.1.1.2.c.5 and 4.8.1.1.2.c.7 to SR 4.8.1.2. A revision l
.is also proposed to Bases 3.0.5 to reflect the clarification from "inde- ;
pendent" circuit to " qualified". circuit. .
The proposed revisions and the reason for the proposed revisions are dis-cussed below;
- 1) Revise LCO 3.8.1.1.a (A.C. Sources - Operating) to read as follows:
"As a minimum, the following A.C. electrical power sources shall be l OPERABLE:
- a. Two qualified circuits between the offsite transmission network and the onsite Class 1E A.C. electrical power distribution system, and" The purpose of the proposed revision is to clarify the Technical Speci-fication LCO regarding the circuits between the offsite transmission
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LAR 95-0004 Paga 2 network and the onsite Class 1E A.C. electrical distribution during operational Modes 1, 2, 3 and 4 consistent with the wording of NRC NUREG-1430, Revision 1, Improved Standard Technical Specifications ;
(ISTS) for Babcock and Vilcox Plants. In addition, it is proposed that the associated Bases 3/4.8, Electrical Power Systems, be expanded by .
adding a discussion of the qualified offsite circuits similar to the ISTS guidance.
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- 2) Revise LCO 3.8.1.2.a to read as follows:
"As a minimum, the following A.C. electrical power sources shall be OPERABLE:
- a. One qualified circuit between the offsite transmission network and the onsite Class 1E A.C. electrical power distribution t system, and" The purpose of this revision is to clarify the Technical Specification LC0 regarding the circuits between the offsite transmission network and :
the onsite Class 1E A.C. electrical power distribution system during l operational Modes 5 and 6 utilizing the guidance of the ISTS.
- 3) Revise SR 4.8.1.1.1 (A.C. Sources - Operating) to be consistent with the proposed revision to LCO 3.8.1.1.a, as follows:
"Each of-the above required qualified circuits between the offsite transmission network and the onsite Class 1E A.C. electrical power dis- ;
tribution system shall bei
- a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability, and
- b. Demonstrated OPERABLE at least once per 18 months during shutdown by transferring (manually and automatically) unit power supply to each of the offsite circuits."
(The ** footnote is proposed for deletion from SR 4.8.1.1.1.b. on TS page 3/4 8-2 because its date of applicability has expired)
- 4) Add to Bases 3/4.8 (Electrical Power Systems) the following discussion of an offsite circuit:
" Qualified offsite to onsite circuits are those that are described in the USAR and are part of the licensing basis for the plant.
An OPERABLE qualified offsite to onsite circuit consists of all I breakers, transformers, switches, interrupting devices, cabling, and l controls required to transmit power from the offsite transmission j network to the onsite Class 1E essential buses.
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' ' l LAR 95-0004' Paga'3 i
An OPERABLE' qualified offsite to onsite circuit consists of:
- 1. One OPERABLE 345 kv transmission line
- 2. One OPERABLE 345 - 13.8 kv startup transformer !
- 3. One OPERABLE 13.8 kv bus, and l
- 4. One OPERABLE 13.8 - 4.16 kv bus tie transformer -
Typically, the electrical power reserve source selector switches.are' selected to the two different startup transformers. However, under !
certain conditions it is appropriate to select both switches to the .
same startup transformer. The circuit in which the startup transformer !
does not have a reserve source selector switch pre-selected to it must. ,
still meet the requirements of having its 345 kv transmission line, I startup transformer, 13.8 kv bus and bus tie transformer OPERABLE. j In the case where a 13.8 kv bus is povered from a startup transformer, !
the reserve source selector switch should be selected to the opposite j startup transformer. !
In MODES 1-4, if one of the required 13.8 kv - 4.16 kv bus tie trans- 1 formers is inoperable, then one qualified offsite to onsite circuit is ;
inoperable and the requirement of LC0 3.8.1.1.a is not met. The appro- j priate corresponding ACTION statement must be entered. The eteential i 4.16 kv volt buses remain OPERABLE vhile energized with one 1!~3 kv - !
4.16 kv bus tie transformer inoperable." i The purpose of this proposed revision is to: provide a discussion in the TS Bases which clarifies qualified circuit operability require- ;
ments7 provide a discussion of the positioning of the reserve source a selec or switches and their effect on operability, and provide a dis-cussion of the effect of the inoperability of a 13.8 kv - 4.16 bus tie ,
transformer. :
- 5) Revise SR 4.8.1.1.2.a (A.C. Sources - Operating) to read as follows: I t
"At least once per 31 days, if Surveillance Requirement 4.8.1.1.2.c has !
not been performed within the previous 31 days, by " !
The purpose of this revision is to eliminate the " STAGGERED TEST BASIS" f surveillance scheduling requirement. l i
- 6) Revise SR 4.8.1.1.2.c (A.C. Sources - Operating) to read as follows: l I
"At least once per 184 days by:"
The purpose of this revision is to eliminate the " STAGGERED TEST BASIS" )
surveillance scheduling requirement. ;
7). Include in the Bases for SR 4.8.1.1.2.a.4 and 4.8.1.1.2.c.4:
" Surveillance Requirements 4.8.1.1.2.a.4 and 4.8.1.1.2.c.4 verify pro-per starting of the Emergency Diesel Generators from standby condi-tions. Verification that an Emergency Diesel Generator has achieved a
.i LAR'95-0004 !
Paga 4- -l I
i frequency of 60 Hz vithin the required time constraints meets the re- ;
o quirement for verifying the Emergency Diesel Generator has accelerated .I to 900 RPM." l The purpose of this revision is to discuss the use of frequency in de- l termining acceptable surveillance test results. !
- 8) Revise TS 4.8.1.2 (A.C. Sources - Shutdown) to read as follows: :
"The above required A.C. electrical power sources shall be demonstrated !
OPERABLE by the performance of each of the Surveillance Requirements of ;
4.8.1.1.1 and 4.8.1.1.2 except for requirements 4.8.1.1.2.a.5, !
4.8.1.1.2.a.7, 4.8.1.1.2.c.5 and 4.8.1.1.2.c.7." l The purpose of this revision is to add exceptions to performing Sur- !
veillance Requirements 4.8.1.1.2.c.5 and 4.8.1.1.2.c.7 which should j have been included with the existing exceptions. j i
- 9) Revise Bases 3.0.5 to be consistent with the proposed use of qualified l circuit in LCO 3.8.1.1. Specifically, reference to "two physically in- l dependent circuits" has been replaced with "two qualified circuits" in j the example discussed in the Bases.
SYSTEMS, COMPONENTS, AND ACTIVITIES AFFECTED: l Technical Specifications for offsite power sources and Emergency Diesel i Generators; and surveillance testing of the, qualified offsite circuits and i the Emergency Diesel Generators. ,
FUNCTIONS OF THE AFFECTED SYSTEMS, COMPONENTS, AND ACTIVITIES:
The onsite.and offsite electric power systems are provided to permit func- ;
tioning of structures, systems, and components important to safety. The ;
safety function for each system, assuming the other system is not function- !
ing, is to provide sufficient capacity and capability to assure that: (1) ;
specified acceptable fuel design limits and design conditions of the re- )
actor coolant pressure boundary are not exceeded as a result of anticipated ;
operational occurrences, and (2) the core is cooled and containment inte- j grity and other vital functions are maintained in the event of po tulated i accidents. ;
Each of the offsite circuits is designed to be available in sufficient time ,
following a loss of all onsite elternating current power supplies and the other offsite electric power circuit, to assure that specified acceptable ,
fuel design limits and design conditions of the reactor coolant pressure l boundary are not exceeded. One of these circuits is designed to be avail- t able within a few seconds following a loss-of-coolant accident to assure j that core cooling, containment integrity, and other vital safety functions ;
are maintained. j l
The Emergency Diesel Generators (EDGs) provide highly reliable, independent i sources of power to the various components necessary for the Engineered )
Safety Features (ESP) systems to function as assumed in the Updated Safety l
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LAR 95-0004 P:g3 5 Analysis Report (USAR). The safety function of the ESF systems is to pro-tect the fuel cladding, ensure Containment Vessel integrity, and reduce the driving force for containment leakage in the event of an accident. As de-scribed in the USAR Section 8.3.1.2.4, Power Distribution System, the star-ting and loading of one EDG is adequate to satisfy the minimum ESF require-ments.
Surveillance testing verifies the availability of the qualified offsite circuits, the ability of each circuit to energize required loads, and the ability of the EDGs to start, load and operate in response to postulated accidents.
EFFECTS ON SAFETY:
System Description
The electrical system design is described in the DBNPS USAR Chapter 8, Electrical Power. Three offsite povered 345 kv lines connect the Toledo Edison transmission grid to the switchyard. The three 345 kv transmission lines access the site by two different right-of-ways. The two 345 kv transmission lines located on the same right-of-way are supported on struc-tures set far enough apart to avoid the possibility of structural collapse of one causing an outage of both lines. The 345 kv switchyard design is a ring bus scheme with ultimate transition to a breaker-and-a-half scheme.
Three overhead 345 kv lines are provided from the switchyard to the onsite station distribution system, one line to each of the two startup transfor-mers and a third line to the main transformer (see Figure 1). Each circuit is capable of carrying full station auxiliary loads assuming the other two circuits are not functioning.
The normal supply to the onsite distribution system during reactor power l operation is the main generator via the unit auxiliary transformer. The reserve electrical power supply and the startup electrical power sources are the two startup transformers. Normally each startup transformer is the reserve power source to one of the two 13.8 kv buses of the onsite distri- I bution system. The transfer of a 13.8 kv bus between the three sources can i be accomplished either manually or automatically. If either startup trans-former is out-of-service the remaining trarsformer vill be available, by manual pre-selection via the reserve source selector switches, to automati-cally supply both buses should the normal source fail. Offsite power is also available by manually removing the generator disconnect links permit-ting backfeed through the main transformer to the unit auxiliary trans-former. The standby emergency power supply is provided by the two EDGs.
Power supply to the 4.16 kv system is from two 12/16 MVA bus tie trans-formers (XFMR AC and XFMR BD) which step down the voltage from 13.8 kv to 4.16 kv (see Figure 2). Each bus tie transformer normally supplies one essential and one nonessential 4.16 kv bus and is available as a reserve source for the other two 4.16 kv busses. The capacities of the transfor-mers and circuit breakers are sufficient to permit full station operation with one bus tie transformer out of service. Each essential 4.16 kv bus is provided with a fast bus transfer scheme which will transfer the bus from its normal source to an alternate source of power.
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LAR 95-0004' Pcgm 6'
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'Two' essential busses C1 and D1 provide power to engineered safety feature
. equipment'for safe shutdown. Two nonessential busses C2 and D2 supply power to nonsafety-related station auxiliaries.
In normal operation, the secondary vinding of each bus tie transformer is !
connected through a 2000 amp circuit breaker (AACC2 or ABDD2) to its asso-ciated nonessential 4.16 kv bus. This bus then feeds the corresponding essential 4.16 kv bus through a 1200 amp circuit breaker (AC110 or AD110).
Each essential 4.16 kv bus can also be energized directly from the other bus tie transformer through a 2000 amp circuit breaker (ABDC1 or AACD1).
Transfer schemes are provided to switch each 4.16 kv bus from its normal bus tie transformer to its reserve. The transfer between the two sources '
is done either manually, initiated by the operator at the control room, or automatically initiated by a protective relay action. Manual transfer is a live bus scheme while automatic transfer is a fast transfer. Two 4.16 kv ;
essential buses of.the onsite distribution system provide power to ESF ,
systems for safe station shutdown. '
The two EDGs are each connected to one of the essential 4.36 kv buses as a standby power source to supply the respective bus upon loss of the normal and reserve power sources. Bus load shedding and isolation, bus transfer to the EDG, and pickup of critical loads are automatic. The EDGs are lo- '
cated in separate, adjacent rooms in the Seismic Class I Auxiliary Build- '
ing.
Provisions are included to minimize the probability of losing the remaining i electric power sources as a result of, or coincident with, a loss of the main generating unit, the transmission network, or the EDGs. ,
Discussion of Changes
- 1) Qualified Circuits i Clarification of " independent" circuit to " qualified" circuit is consistent with the guidance of the Improved Standard Technical Specifications (ISTS) for Babcock and Wilcox Plants (NUREG-1430, Revision 1). As discussed in i the revised ISTS Bases, qualified offsite circuits are those that are de- l scribed in the Updated Safety Analysis Report (USAR) and are part of the licensing basis for the plant. Details of the existing listing of offsite circuits are being relocated to the Bases consistent with the ISTS.
The two 13.8 kv - 4.16 kv bus tie transformers are components of the two l qualified circuits between the offsite transmission network and the onsite-class 1E distribution because of their function of providing A.C. power to the onsite power distribution systems. These bus tie transformers are re-quired to'be operable under TS 3.8.1.1 (A.C. Sources - Operating) and are, therefore, included in the listing of qualified offsite to onsite circuits.
These changes do not alter the design or function of the offsite power sources as described in the USAR. Conformance with 10 CFR 50 Appendix A !
General Design Criteria 17, Electric Power Systems, and General Design Cri- I teria 18. Inspection and Testing of Electric Power Systems, as described in
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LAR 95-0004 P ga 7-USAR Sections 3D.1.13 and 3D.1.14 is not affected. Relocation of the qual-ified offsite to onsite circuit operability discussion to the Bases is consistent with NUREG-1430 and does not affect the design or the function of the offsite circuits.
- 2) Reserve Source Selector Switches The reserve source selector switches are described in Chapter 8 of the Updated Safety Analysis Report (USAR). USAR Section 8.1.2.1 states, in part:
When the unit is in normal operation with auxiliary power supplied through unit auxiliary transformer, the occurrence of any one of the above conditions originating in the grid system or main generator sys-tem will result in isolation of the turbine generator unit from the 345kV grid system by opening breaker 34560 and 34561. The 13.8kV buses A and B are immediately fast transferred from the unit auxiliary transformer 11 to the startup transformer (s) 01 and/or 02. The speci-fic startup transformer (s) is determined by pre-selection using the re-serve source selector switches. These switches can align either start- ,
up transformer to each 13.8kV bus.
USAR Section 8.2.1 states, in part:
The design of the offsite power system shows that the requirements of General Design Criteria 17 vill be met even with one startup trans-former out of service.
USAR Section 8.3.1.1.1 states, in part:
Normally each startup transformer is the reserve power source of only I one 13.8kV bus. However, if either transformer is out of service, the remaining startup transformer is available (by manual pre-selection) to :
automatically supply both 13.8kV buses should the normal source ]1 (auxiliary transformer) fail.
USAR Section 8.3.1.1.2 states, in part:
A startup transformer is available as a reserve source to a bus if:
- a. Its secondary voltage is normal. i
- b. Its protective lockout relay is not tripped.
- c. The bus feeder breaker closing DC voltage is available.
Section 8.2 of NUREG-0136, NRC Safety Evaluation Report for the DBNPS NPF-3 Operating License states, in part:
Normally each start-up transformer is the reserve power source to one ;
13.8 kilovolt bus. However, if either start-up transformer is out of service, the remaining transformer vill be available (by manual pre-selection) to automatically supply both buses should the unit auxi-liary transformer (normal pover) fail.
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- Pega 8 It is also important to note that in consideration of the positioning of
~the reserve source selector switches, General Design Criteria 17 states:
' Provisions shall be included to minimize the probability of losing l electric power from any of the remaining supplies as a result of, or coincident with, the loss of power generated by the nuclear power unit, i the loss of power from the transmission network, or the loss of power from the onsite electric power supplies. :
Therefore, per GDC 17 positioning of the selector switches should minimize (
the likelihood of losing power to the onsite distribution system upon the !
loss of the auxiliary transformer power supply due to the plec *s main gen- q erator tripping.
Accordingly, if either startup transformer is out-of-service the remaining }
transformer vill be available, by manual pre-selection via the reserve !
source selector switches, to automatically supply both buses should the ,
normal source fail. Additionally, if the ring bus is configured such that ;
upon loss of the auxiliary transformer the feed to one startup transformer !'
vill be lost, the remaining transformer vill be available, by manual pre-selection via the reserve source selector switches, to automatically supply ,
both buses should the normal source fail. As discussed above the selecting of both reserve source selector switches to the same start-up transformer has been previously reviewed by the NRC in NUREG-0136. Therefore, the ad- ,
dition of the proposed information to the Bases has no adverse effect on safety.
- 3) Deletion of Surveillance Extension !
Footnote ** for TS 4.8.1.1.1.b reads as follows: ;
"The 18 month surveillance which is due on March 1, 1988 may be !
delayed until April 1, 1988." !
Deletion of this expired footnote from TS 4.8.1.1.1.b is administrative and does not affect the function of the offsite circuits.
- 4) Deletion of STAGGERED TEST BASIS The deletion of " STAGGERED TEST BASIS" from TS 4.8.1.1.2.a and 4.8.1.1.2.c provides increased flexibility in scheduling of these EDG tests and is con-sistent with the ISTS. Each EDG must still be tested at least once per 31 days. The testing method and acceptance criteria for demonstrating EDG operability is not altered nor is a new test created.
Independence and physical separation between the two EDGs and the other i power sources is maintained so that no credible single event will disable l more than one unit. Technical Specification 3.8.1.1 Action statements re- '
quire the starting of an EDG vithin 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when the other EDG is deter-mined to be inoperable to verify that a common mode failure does not exist.
Further, USAR Section 8.3.1.2.7, Testing, requires that only one EDG be tested at any one time; that during Modes 1, 2, 3 or 4 that an EDG can be tied to the grid only if the other EDG is operable; and that during Modes 5 or 6 vith one EDG inoperable the other EDG may be started and tied to the
r LAR 95-0004' P ga 9 grid for testing provided that all operations involving core alterations or positive reactivity changes are suspended until the EDG is restored to operable status.
Therefore, deletion of the STAGGERED TEST BASIS would not create the possi-bility of a common mode failure. This change in the EDGs surveillance test schedule does not adversely affect the safety function of the EDGs.
- 5) Exceptions to TS 4.8.1.2 Surveillance Requirement (SR) 4.8.1.1.2.c was added by Operating License Amendment 97 to reduce the number of EDG cold starts. SR 4.8.1.1.2.c ver-ifies the fast start capability of the EDGs once per 184 days rather than monthly as previously required. SR 4.8.1.1.2.a is similar to SR 4.8.1.1.2.c but it allows EDG varm-up and is performed on a 31 day test frequency. SR 4.8.1.1.2.a states that credit may be taken for the perfor-mance of SR 4.8.1.1.2.c. The existing exception in SR 4.8.1.2 for SR 4.8.1.1.2.a.5, verification that the EDG is synchronized and loaded for greater than 60 minutes, is part of the original licensing basis for the DBNPS. This exception was granted because only one EDG is required in the Technical Specifications mode of applicability (Modes 5 and 6) and it is not desirable to put it in a synchronized condition. SR 4.8.1.1.2.c.5 is a similar surveillance test for synchronizing and loading the EDGs as SR 4.8.1.1.2.a.5. Adding the exception to 4.8.1.2 of synchronizing and load-ing the EDGs under TS 4.8.1.1.2.c.5 is consistent with the exception to SR 4.8.1.2 for SR 4.8.1.1.2.a.5. Therefore, exception of SR 4.8.1.1.2.c.5 in SR 4.8.1.2 does not affect the safety function of the EDGs.
Amendment 75 to the Operating License added the existing exception to SR 4.8.1.2 for SR 4.8.1.1.2.a.7, verification that the automatic load sequence timer is operable. As discussed in the amendment's Safety Evaluation by the NRC Staff, the load sequencer tested by SR 4.8.1.1.2.a.7 is required to be operable only when the unit is in an operational mode other than cold i shutdown (Mode 5) or refueling (Mode 6) per TS 3.3.2.1, Safety Features Actuation Instrumentation. SR 4.8.1.2 is applicable when the unit is in a cold shutdown or refueling condition. During cold shutdown and refueling '
operational modes the load sequencer is not required as the reactor coolant system is sufficiently cooled down and depressurized eliminating the need to sequence the loading of emergency loads on the EDG. The surveillance test required by SR 4.8.1.1.2.c.7 is similar to SR 4.8.1.1.2.a.7.
Therefore, adding the exception of this surveillance test does not affect the safety function of the EDGs.
- 6) EDG Acceleration Measurement Bases 3/4.8 is revised to address the use of frequency measurement for ver-ifying the EDG acceleration to 900 RPM as required by SR 4.8.1.1.2.a.4 and SR 4.8.1.1.2.c.4. Frequency is an equivalent measurement to speed or RPM.
This additional information does not affect the safety function of the EDG.
LAR 95-0004 Pcg2 10
- 7) Change to Bases 3.0.5 T'he change to Bases 3.0.5 is administrative to bring the Bases into agree-ment with the proposed change from " independent" to " qualified" circuits.
This change does not affect the safety function of the offsite circuits.
SIGNIFICANT HAZARDS CONSIDERATION:
The Nuclear Regulatory Commission has provided standards in 10 CFR 50.92(c) for determining whether a significant hazard exists due to a proposed amendment to an Operating License for a facility. A proposed amendment involves no significant hazards consideration if operation of the facility in accordance with the proposed changes vould: (1) Not involve a signifi-cant increase in the probability or consequences of an accident previously evaluated; (2) Not create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Not involve a sig-nificant reduction in a margin of safety. Toledo Edison has reviewed the proposed changes and determined that a significant hazards consideration does not exist because operation of the Davis-Besse Nuclear Power Station, Unit No. 1 in accordance with these changes vould:
la. Not involve a significant increase in the probability of an accident previously evaluated because the proposed changes do not make a change to any accident initiator, initiating condition or assumption. The proposed changes do not involve a significant change to the plant de-sign or operation. The proposed changes do not affect the safety func-tion of the offsite circuits or EDGs.
Ib. Not involve a significant increase in the consequences of an accident previously evaluated because the proposed changes do not invalidate assumptions used in evaluating the radiological consequences of an ac-cident, do not alter the source term or containment isolation and do not provide a new radiation release path or alter potential radiolog-ical releases.
- 2. Not create the possibility of a new or different kind of accident from any accident previously evaluated because the proposed changes do not ,
introduce a new or different accident initiator or introduce a new or different equipment failure mode or mechanism.
- 3. Not involve a significant reduction in a margin of safety because the proposed changes do not reduce the margin to safety which exists in the present Technical Specifications or Updated Safety Analysis Report.
The operability requirements of the Technical Specifications are con-sistent with the initial condition assumptions of the safety analyses.
Further, the proposed changes do not affect the Action statement re-quirements for the various levels of degradation in the offsite cir-cuits or EDGs.
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- Pcg3 11-CONCLUSION
R 'On the basis.of the above, Toledo Edison has determined that the License h Amendment Request does not involve a significant hazards consideration. ' As -
this License Amendment Request concerns a proposed change to the Technical y Specifications that must be reviewed by the Nuclear Regulatory Commission, this License Amendment does not constitute an unreviewed safety question.
I ATTACIDENT:
i Attached are the proposed marked-up changes to the Operating License.
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LAR 95-0004 P:g2 12
REFERENCES:
- 1. Updated Safety Analysis Report Section 3D.1.13, Criterion 17 - Electric Power Systems.
- 2. Updated Safety Analysis Report Section 3D.1.14, Criterion 18 -
Inspection and Testing of Electric Power Systems.
- 3. Updated Safety Analysis Report Chapter 8, Electrical Power
- 4. Technical Specification Interpretation Request 91-002, Rev. 0
- 5. NUREG-0136 cnd Supplement 1, NRC Safety Evaluation Report for the DBNPS NPF-3 Operating License, Section 8.2, Offsite Power System.
- 6. NUREG-1430, Revision 1, Improved Standard Technical Specifications for Babcock and Vilcox Plants.
- 7. 10 CFR 50 Appendix A, General Design Criteria.
- 8. IEEE Standard 308-1971, Criteria for Class 1E Power Systems for Nuclear Power Generating Stations.
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- LAR 95-0004'
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INFORilATION ONLY l 1
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