ML20149F470

Draft Ltr Discussing Application for Temporary Partial Exemption from 10CFR50,App a General Design Criterion 17 & Amend of License NPF-62 for Plant

ML20149F470
Person / Time
Site:	Clinton
Issue date:	07/21/1997
From:	Romberg W ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LS-97-004, LS-97-4, NUDOCS 9707220203
Download: ML20149F470 (28)

Text

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EI7/21/97 15[46 CPS

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DRAFT U 602XXX l 8E.100a 10CFR50.12 Docket No. 50-461 10CFR50.90 Document Control Desk Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Application for Temporary Partial Exemption firom 10CFR50 Appendix A General Design Criterion 17 and Amendment of Facility Operating License No. NPF-62 for Clinton Power Station (LS-97-004)

Dear Madam or Sir:

During the current refueling outage at Clinton Power Station (CPS), Illinois Power Company (IP) recently determined that, for short and intermittent periods of time, voltage on one of the offsite sources for CPS is not able to be maintained above the minimum required value conservatively established for CPS.' (The other offsite source voltage continues to be acceptable.) This is primarily due to the fact that unusually low voltages are occurring as a result of the current lack of operating generators in Illinois, coupled with high load demands during peak hours. All possible measures, short of interrupting service to customers, have been taken to support the offsite source voltage.

Notwithstanding, IP believes that plant operation is justified considering that continually acceptable voltage has been indicated for the other offsite source, and measures have been taken to ensure operators will know when voltage on the vulnerable bus may be inadequate in the event of a plant trip.

This issue was discussed in a meeting between NRC staff and IP personnel on July 17,1997, with the intent of achieving a resolution to the issue that would support IP's scheduled plant startup from the current refueling outage. Based on the meeting.

discussion, a means to resolve this issue via the license amendment process was j proposed. However, during subsequent teleconferences with the NRC Staff the l conclusion was reached that the 10CFR50.12 exemption process was necessary to

implement the proposed changes. Accordingly, pursuant to 10CFR50.12 and l

10CFR50.90, IP hereby applies for a one time exemption to 10CFR50 Appendix A, General Design Criteria (GDC) 17, and amendment of the CPS Operating License, No.

'. NPF-62.

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07/21/97 15:46 CPS

• LICENSING + 13014153061 NO.318 DB2 l .

U-602XXX DRAFT To reflect IP's intention to operate CPS with the identified offsite source 1

l condition, and based on a temporary partial exemption to GDC 17, IP proposes to revtse paragraph 2.D of the Operating License, Technical Specification (TS) Section 3.8.1, "AC Sources - Operating," and the Bases for TS Section 3.8.1.

A description of the pmposed changes and associatedjustification (including a Basis For No Signi6eant Hazads Consideration) are provided in Attachment 2. A marked-up copy of the affected pages from the Operating License is provided in' Attachment 3. A marked up copy of the affected pages from the TS is provided in l

Attachment 4. A marked up copy of the affected pages from the TS Bases is provided in Attachment 5. An Environmental Assessment is included in Attachment 6. Ftuther, an affidavit supporting the facts set forth in this letter and its ="ahhments is provided in '

Attachment 1. Following NRC approval of this request, IP will revise the CPS TS Bases in accordance with TS 5.5.11, " Technical Specification (TS) Bases Control Program," to incorporate the changes identified in Attachment 5.

Currently, CPS is in a shutdown condition (Mode 4) for its sixnt refueling outage (RF-6). IP is scheduled to commence restart of the plant on July 26,1997. This l temporary partial exemption and corresponding license amendment are needed prior to resuming operation, and failure of the NRC to act in a timely manner would delay the planned startup. Unique circumstances have arisen this summer which collectively result in unprecedented demands on the electrical transmission systems connected to CPS.

These circumstances include an unforeseen low regional generating capacity due to extended outages at a large number of neighboring power plants, combined with high peak demands during hot-weather days. While the situation does not present a challenge to grid stability, this combination of events has caused periods oflow system voltages such that this temporary partial exemption and corresponding license amendment request have become necessary. In light of these circumeamces and the need to support plant startup, IP respectfully requests prompt NRC review and approval of this application for a temporary partial exemption from the requirements of10CFR50, Appendix A, GDC 17, as well as review and approval of the associated license amendment on an emergency basis in accordance with 10CFR50.91(a)(5).

Sincerely yours, Wayne D. Romberg l Assistant'Vice President TBE:

Attachments

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U-602XXX DRAFT cc: NRC Clinton Licensing Project Manager NRC Resident Office,V-690 Regional Administrator, Region III, USNRC Illinois Department of Nuclear Safety W

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Attachment 1 to U402XXX 1

1 Wayne D. Romberg, being first duly sworn, deposes and says: That he is Assistant Vice President ofIllinois Power; that this application for partial exemption from General Design Criterion 17 of 10CFR50 Appendix A and for amendment of Facility Operating License NPF42 has been prepared under his e- kion and direction; that he knows the contents thereof; and that to the best of his knowledge and belief said letter and the facts contained therein are true and correct.

Date: 1his day of July,1997.

s Signed:

Wayne D. Romberg STATE OFILLINOIS l SS.

f COUNTY j Subscribed and sworn to before me this day ofJuly 1997.

l (Notary Pubile) e

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j. Anachment 2 to U-602XXX DRAFT l

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l l CPS s'letrical Dietribwien Svatam  !

4 10CFR50, Appendix A, General Design Criterion (ODC) 17, Electrical Power y

Systems, requires that an onsite and an offsite electric power system be provided to l j permit functioning of structures, systems, and components important to safety. 'Ihe

{

safety fbaction for each of these two systems (assuming the other system is not j functioning) is to provide sufficient capacity and capability to assure that: (1) speci6ed  ;

acceptable fbel design limits and design conditions of the reactor coolant pressure

boundary are not exceeded as a result of anticipated operational occurrences, and (2) the <

i core is cooled and containment integrity and other vital functions are maintained in the '

j event ofpostulated accidents. '

ODC 17 also requires that electric power from the transmission network to the

onsite electric distribution system shall be supplied by two physically imiWent circuits (not necessarily on separate rights of way) designed and located so as to minimize j

to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. Additionally, each of these circuits are j requhed to be designed to be available in sufficient time following a loss of all onsite alternating current power supplies and the other offsite electric power circuit, to assure i that specified acceptable fuel design limit and design conditions of tN reactor coolant l pressure boundary are not exceeded. One of these circuits shall be designed to be i available within a few seconds following a loss-of coolant accident to assure that the core l cooling, containment integrity, and other vital safety functions are maintained.

)

l Evaluation against ODC Criterion 17 is described in the Clinton Power Station

} (CPS) Updated Safety Analysis Report (USAR) Section 3.1.2.2.8.1. Onsite and offsite j electric power systems are provided for CPS to permit the functioning of structures, systems and components important to safety. The Class IE electric power system for j- CPS consists of three electrically and physically independent distribution divisions. The onsite power supplies for each of these three divisions consist of a diesel generator and a i

battery rupply. (A fourth Class 1 E battery supply is utilized for portions of the l emergency core cooling and reactor protection systems.) Class IE loads with redundant 3

safety functions are assigned to redundant divisions. The redundancy of the Class 1E load functions is such that the nuclear safety of the station is not degraded when electrical

}

power is lost to one division due to a single failure.

j The three redundant distribution divisions which comprise the onsite electric j power system are supplied with electric power from the transmission network via two physically independent ' circuits. One of these offsite sources is a 345-kV circuit (fed by j three transmissbn lines) from the switchyard through the Reseive Auxiliary Transformer j (RAT), and the other is a 138-kV circuit (fed by one transmission line) from the IP grid j system through the Emergency Reserve Auxiliary Transfonner (ERAT). 'Ihe 138 kV and

345 kV transmission lines used as the offsite power supplies are on physically separate i rights of way and are electrically Mdependent as described in USAR section 8.2.1.1 and n

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1

07/21/97 15:48 CPS

• LICENSING 4 13014153061 NO.318 D06 Anachment 2 to U-602XXX DRAFT =x 8.2.2.1. The 345 kV and 138-kV transmission lines and their associated stmetures are 1

i designed to successfully withstand environmental conditions prevalent in the area (wind, ,

temperature, lightning, floc d, etc.), thus minimizing almultaneous failure. l l

Chapter 15 of the USAR discusses the effects of anticipated process disturbances to determine their consequences and the capability of the plant to control or accommodate such events. Subsection 15.2.6 discusses loss ofAC power, including loss of grid. This discussion demonstrates that fuel design limits and reactor coolant pressure boundary design conditions are not exceeded.

Background

Prior to the current refueling outage (RF-6) at Clinton Power Station (CPS),

Illinois Power (IP) recognized that with offsite voltage at its minimum expected value, the auxiliary electrical power disuibution system at CPS may not provide adequate voltage to certain plant electrical loads at the 120-volt level. Modifications were thus planned to replace certain 120-volt distribution transformers with regulating transformers to regulate voltage for the potentially affected loads. In addition, because it was also previously recognized that the degraded voltage protection relays and their setpoints were not sufficient to provide automatic degraded voltage protection over the full range of voltage to ensure proper operation of all Class IE equipment, modifications were also planned for installing new, more accurate relays for proper degraded voltage protection.

(Amendraent 110 to the CPS Operating License was issued to support installation of the new relays with new setpoints.)

Installation of the relays for all three safety-related 4160-V buses at CPS was completed during RF-6. However, upon installation of the first of the 120-V regulating transformers, a problem was experienced. The new transformers were found to be particularly sensitive to radio frequency and electromagnetic interference such that their intemal protective circuitry was causing spurious trips of one of the~ transformers. It was therefore decided to reinstall the original non-regulating transformers for the 120-V distribution panels. A new approach to resolving the long-term problem is currently under development, but in the short term (i.e., during the current refueling outage) it was determined that other changes would be made to the auxiliary power system to ensure adequate voltage to the critical 120-volt loads. 'Ihe changes involved changing the tap settings on the Reserve Auxiliary Transformer (RAT), Emergency Reserve Auxiliary Tran sformer (ERAT), and selected distribution transformers to provide an overall boost in voltage to the critical 120-volt loads. Extensive calculations at a very detailed and l unprecedented level were performed to support these changes as careful considerr tion i had to be given to providing the needed boost in voltage to the critical 120-volt loads

( whhout excessively boosting voltage to other plant loads. The most recently determined i

value for the minimum expected offsite voltage (as determined by a model provided by l

the Mid-America Interconnected Network (MAIN)) was utilized in these calculations.

These transformer modifications were completed in late June,1997. IP anticipates that

07/21/97 15:49 CPS *L1 CENSING

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Anschmem 2 to U-602XXX DRAFT = 1 l

plant modificationa to " permanently" resolve adequate voltage concerns for all CPS plant loads will be installed prior to next summer (1998).

Also during late June,1997, IP began to closely monitor voltage on the 138 kV and 345-kV systems (while the plant was still offline). This was prompted by the fact  !

that, at times, voltages were lower than anticipated. IP was concerned that the current l situation in the midwestem United States, i.e., the current lack of generating capacity due ,

to the number of shutdown units, combined with periods of peak summer demand during  ;

hot weather, may cause periods of unusually low voltage on the 138-kV and 345-kV systems. CPS Operations also worked with the IP Dispatch Center to establish measures for maintaining voltage on both of the systems at an acceptable level These measures  ;

consist of: (1) switching capecitor banks on the system, (2) increasing VAR output from other generating units, and (3) switching /reconfiguring the system.

1 Additionally, in anticipation of plant startup, a " predictor model".is being utilized I I

to be able to inform operating personnel of when offsite circuit voltages may not be acceptable immediately following a plant trip. This was necessary since, while CPS is supplying power to the grid, voltages are normally higher than when the plant is offline, and thus the true offline voltage condition could be masked. The predictor model considers system configurations and predicted daily load demands to determine minimum grid voltages for the day and voltage acceptability to CPS requirements. Monitoring the 345-kV and 138-kV system voltages while the plant was offline provided a means of validating the accuracy of the predictor model.

For the pgriod between June 23 and July 17,1997,(25 days) monitoring of the 345-kV system voltage yielded the following results:

• I day where system voltage was less than minimum expected for 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />,

• 16 days where system voltage was always greater than minimum expected

. System voltage was less than minimum expected for 66 hours7.638889e-4 days <br />0.0183 hours <br />1.09127e-4 weeks <br />2.5113e-5 months <br /> during a total observed period of 598 hours0.00692 days <br />0.166 hours <br />9.887566e-4 weeks <br />2.27539e-4 months <br />.

For the period between June 25 and July 17,1997 (23 days), monitoring of the 138-kV system voltage demonstrated that voltage remained above the acceptable limit thmughout that period.

The voltages seen for the 345 kV system during this period were lower than what was anticipated. In anticipation of the summer demand it was expected ths.t implementation of the previously described measures would be sufficient for maintaining offsite source voltages within acceptable values. As nota.d above, success was achieved for the 138-kV system, but the 345-kV system has demonstrated that it cannot be I maintained such that its voltage will be within acceptable values 100 percent of the time for the remainder of the summer without curtailing electrical service to customers.

j However, a simulated exercise conducted by the IP Dispatch Center on July 16,1997 l demonstrated that in the event of an accident at CPS, offsite electrical supply voltages can be fully recovered in a reasonably short period of time (less than 10 minutes) by ahedding

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Attachment 2 toU402XXX DRAFT =

other loads on the system. On this basis, a degraded 345-kV system can be considered a j " delayed access" source for CPS.

l 4

l Similarly, in the unlikely event that 138-kV system voltage is inadequate while J

the 345-kV system has adequate voltage, IP has determined that 138-kV system voltage

can be restored in the same time frame, nus, it may also be considered a " delayed

access" source for CPS.

i he unexpected difficulty with offsite source voltage this summer prompted IP to reevaluate the design basis for CPS relative to Criterion 17. On the basis that the 138-kV j system voltage can be maintained within acceptable limits, and that a low voltage i condition on the 345-kV system can be quickly recovered (or conversely, that the 345-kV l system voltage can be maintained within acceptable limits, and that a low voltage

] condition on the 138-kV system can be quickly recovered) IP's position is that a power j supply configuration with one immediate access source and one access source that

intermittently provides inadequate voltage, but is quickly recoverable, still in fact meets j the intent of General Design Criterion (GDC) 17. He CPS USAR and the Safety j Evaluation Report (NUREG-0853) for CPS affirm that the original design of the CPS l electric power system design is in conformance with GDC 17.

J

) Meetine Conducted with NRC on July 17.1997 i

i On July 17,1997, a meeting between IP and NRC staff personnel was conducted l to discuss the offsite voltese situation for CPS and IP's position' regarding continued j conformance to QDC 17. IP reviewed the issues and events leading to the current

situation, including the unforeseen difficulty with maintaining 345-kV system voltage j

within the limits recently established for CPS. IP presented its position that plant j operation with low (but recoverable) voltage on one of the two offsite sources is i consistent with ODC 17 and thus still meets the design / licensing basis for the facility. l l ne NRC staff disagreed with IP's position. They noted that, although the Safety

{ Evaluation Report (SER) for CPS is silent with respect to any discussion about delayed j and immediate access sources, their review and evaluation was based on the CPS design i of having two offsite independent circuits that are both continuously available as i

immediate access sources. ney noted that the SER is silent on the use of these terms

! because there was no need to evaluate the acceptability of a delayed source at the time i CPS was licensed. Although the CPS design (under normal conditions) more than meets f the requirements of GDC 17, the NRC staff's postion is that the CPS lic.msing basis i assumes two independent, otYsite, immediate access electric power sources.

j 1mplementation ofIP's position would thus constitute a change to the CPS licensing

' basis, and requires NRC approval.

i l Following the July 17 meeting, a follow-up teleconference between IP and NRC

! staff personnel was conducted to further discuss the inue. In that follow-up discussion i the NRC expressed its position that although GDC 17 requires only one of the two offsite i

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sources to be immediately available (i.e., within a few seconds follo~ wing a loss-of- -

coolant accident), the ODC also states, "The safety function for each system (i.e., the

' onsite electric power system and the offsite electric power system] shall be to provide su#clent capacity and capability to assure that (1) specified fuel des!gn limits and design conditions of the reactor coolant pressurc boundary are not awcMed as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents." (emphasis added) A source having less than adequate voltage, according to the NRC's staff position, is not a source that has sufclent capacity and capability, regardless of the fact i

that, in the event the source is needed, the source voltage may.be quickly recovered (by shedding load for example). Although such a source is similar to a source with " delayed

, access" as permitted by GDC 17 for one of the two required offsite sources, it cannot bc

regarded as such. Thus, a partial exemption from the requirements of GDC 17 is required j to implement the changes proposed by IP.

i Descrintion of Pronosed Chance 4

In accordamce with 10CFR50.12,IP is requesting a temporary partial exemption from the requirements of 10CFR50 Appendix A General Design Criterion (GDC) 17.

j GDC 17 specifically requires the availability of two physically independent offsite electrical circuits of sufficient capacity and capability. The temporary partial exemption is requested for the intermittent periods during peak summer demand that the grid voltage, and thus its capacity and capability, is below acceptable levels as calculated for

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CPS. This temporary partial exemption will only be effective up to and including October 15,1997e In accordance with 10CFR50.90, the following changes to Operating License No.

NPF-62 for CPS are being proposed:

(1) Paragraph 2.D is being revised to acknowledge the proposed temporary partial exemption to the requirements of GDC 17 to allow plant operation while one of the two independent offsite electrical circuits is experiencing intermittent (but quickly recoverabic) periods ofless-than-adequate volta 8e. In addition, this

{ revision acknowledges that the special circumstances associated with this proposed exemption will be addressed in the safety evaluation accompanying the j associated amendment to the Operating License.

d (2) Technical Specification (TS) 3.8.1, "AC Sources - Operating," is being revised to 4

include a note to clarify that, based on the current, temporary offsite source voltage situation, the two required offsite sources for CPS may not both be

immediate access sources due to less-than-acceptable voltage.

nese. proposed changes will also be reflected in the Bases for TS 3.8.1 as described in Attachment 5. The TS Bases proposed change will clarify what action must be taken in

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• 130t4153061 NO.318 D10 i i

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l DRAFT =x the event that voltge on either or both of the offsite sources is below acceptable limits.

l As discussed lat'er, IP has h mined that the proposed change involves no significant

hazards consideration.

j Justification for FF--:#M Channe i

i As discussed previously, IP's current licensing basis is based on the CPS design

) in which the two independent offsite electric power sources for CPS (mquired to be

} centinuously connected or OPERABLE per CPS TS 3.8.1) are "immediate access sources." IP proposes that with the voltage of one offsite source less than the minimum I required voltage, the source may be regarded as a delayed access source, while the j remaining source continues to bc an immediate access source. Although this is a i

reduction in the level of commitment established by IP's original licensing basis, this i configuration continues to satisfy the underlying purpose of GDC 17 for an acceptable i

, design, as further disettssed below. It should be emphaei=A that this configuration is not

! continuous (it exists only intermittently) and is not long term (it is expected to no longer i exist after summer concludes). Further, as no^4d previously, IP anticipates that plant i modifications to " permanently" resolve adequate voltage concems for all plant loads will l be installed prior to next summer (1998). Therefore, the requ'ested amendment is j intended to be effective only until the peak 1997 summer demand is over.

! The following is an assessment ofIP's proposed change against each of the four j criteria contained in GDC 17 regarding required offsite electric power supplies / circuits:

j (1) " Electric popr from the transmission network to the onsite electric distribution

system shall be supplied by two physically independent circuits (not zwmarily on i

separate rights of way) designed and located so as to minimize to the extent practical the 4

likelihood of their simultaneous failure under operating and postulated accident and i environmental conditions."

l

! CPS Compliance: CPS compliance with this requirement is unaffected as the proposed change does not change the design of the offsite electric power sources with respect to j their independence and the likelihood of simultaneous failure.

l t (2) " Provisions shall be included to minimize the probability oflosing 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, the loss of power from the. transmission network, or j the loss of power from the onsite electric power supplies."

i

) CPS Comoliance: Because the proposed change does not affect tb independence of the i onsite and offsite electric power supplies, it does not increase the probability oflosing

} power from any of the remaining supplies as a result of the loss of power from the I transmission network (i.e., the other offsite source) or the loss of power from the onsite

power supplies. With respect to any increase in the probability oflosing power from the

, remaining supplies as a result of, or coincident with, the loss ofpower generated by the e

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Anachment 2 to U-602XXX DRAFT =

nuclear unit, or coincident with the loss ofpower from the onsite electric power supplies or the other offsite source, these criteria are still satisfied to the extent that GDC 17 permits use of a delayed access source. The probability of failure of the rammining l supplies occumng coincident with an offsite source being degraded due to low voltage is

increased, but the probability of such coincident rar4m failures will still be quite small.

With regard to the probability of completely losing tae offsite source that is degraded by

low voltage and is separated from the plant by the degraded voltage protection relays following a plant trip, IP has demonstrated that the source voltage (and thus the source) can be quickly recovered in the event of an emergency. This recovery period is well within the time normally accepted for a delayed access source that meets the requirements of GDC 17.

(3) "One of these [offsite electric power] circuits shall be designed to be available within a few seconds following a loss-of coolant accident to assure that core cooling,

containment integrity, and other vital safety functions are maintained."

CPS Comoliance: With one offsite source considered to be a " delayed access source,"

the remaining source will continue to serve as the "immediate access source." By design,

. each of the two offsite sources for CPS is normally continuously available. Thus, either

source is capable of being the immediate access source that is "available within a few seconds" following a loss-of-coolant accident. Continued compliance with this criterion will thus exist.

(4) "Each of these (offsite electric power) circuits shall be designed'to be available in sufficient time following a loss of all onsite altemating current power supplies and the other offsite elect'ric power circuit, to assure that specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded."

l CPS Comoligara: As noted above, each of the offsite electric power circuits is (normally) an immediate access cimuit. However, if voltage on an offsite circuit is less than the minimum required value, IP will regard the circuit as a " delayed access" circuit that meets the above criterion. Through discussion with the IP Dispatch Center, and by i performance of an exercise at the dispatch center to detennine how long it would take to recover voltage on an offsite circuit having less than acceptable voltage during an emergency at CPS (for which a plant trip would be expected), IP determined that voltage can be quickly recovered through the interruption of power service to customers. The expected time is less than the amount of time accepted for many plants where the delayed access source may involve disconnecting links or performing switching operations or breaker realignments in order to connect the credited source. Further, although conditions are not fully comoarable, as an additional gauge on the acceptability of the i recovery or delay time determined for a CPS delayed access source,IP's coping analysis for a station blackout as defined in 10CFR50.2 indicates the capability to withstand a Station Blackout (SBO) of four hour duration.

I

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l As noted previously, due to the problem encountered with the plant modification

mvolving the installation of regulating transformers during the current refueling outage, l and the subsequent decision to not proceed with that modification, IP determined to make  !

what a4ustments or changes it could to the existing auxiliary power system to provide

{ adequate voltage to the critical 120-volt loads. The calculations required to support that l effort 'were extremely extensive and detailed and were focused to an unprecedented l degree down to the 120-volt level This resulted in well founded but more limiting l required plant voltage values at the 4160 VAC safety bus level when the 120-volt required load voltages were reflected at that level. It was also rmaiW that there

!' would be reduced operating margins with respect to offsite source voltages as the summer j approached, but IP's expectation was that sufficient measures could be taken to rnalatnin i offsite voltage above the levels required to support CPS. Ir, addition, the current

! unavailability of generators in Illinois and the incmased summer demand have' j contributed to offsite source voltages that are lower than expected, particularly on the .

i 345-kV system. All possible measures have been taken to, boost grid voltage during high l l demand, short ofinterrupting service to IP's customers, but these measures have not been l s' access?al in ensuring that the 345-kV system voltage meets or exceeds 'the minimum j requirement for CPS.

In light of the above, and in anticipation of plant startup froin the current refueling

! outage, the previously described predictor model is being utilized to enhance IP's

! cape.bility to ascertain what the grid voltage situation is while CPS is on line supporting the grid, compared to what the grid voltages would be in the event that CPS would trip or be forced to shut down. This provides a tool to qualitatively assess when there is incitased risk asweisted with any degradation of the offsite source voltages while the j plant is operating since such risk would otherwise be masked with the plant on line. IP j believes that this effort reflects a conservative approach that balances risk concems with the need for plant operation to support the needs ofIP's customers. Given that GDC 17 provides the primary criterion for an acceptable offsite source configuration,'and given that IP's proposed change supports a configuration that achieves the underlying purpose

of GDC 17, through the monitoring of the grid by application ~of the predictive model, IP i

believes that operation of CPS in accordance with the proposed change does not compromise safety.

Basis for No Signh% ant Hs :ards Considemtions As noted previously, IP proposes to revise the CPS Technical Specification (TS)

Bases to allow plant operation with only one of the two offsite electrical circuits available '

within a few seconds. In accordance with 10CFR50.92, a proposed change to the operating license (or TS) involves no significant hazards consideration if operation of the facility in accordance with the proposed change would not: (1) involve a significant increase in the probability or consequences of any accident previously evaluated, (2) create the possibility of a new or different kind of accident from any accident previously

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evaluated, or (3) involve a significant reduction in a margin of safety. This request is

evaluated against each of these criteria below.

1 (1) The proposed change involves no physical change to plant systems, structures or

. components. Further, under the proposed change, CPS will still be required to

! maintain one of the offsite sources as an "i==adiate access source". However, j

the proposed change does permit low voltages to exist on an offsite source (relative to the needs of CPS plant loads) for interminent periods of time. This

! may slightly increase the probability of a failure occurring concurrent with another source inoperable (which could involve, for example, an increase in the probability of a short term loss of offs!te power), or slightly increase the probability of a malfunction ofsafety-related equipment.' However, these i

increases would be expected to be small. Automatic degraded voltage protection for plant loads will not be affected, so there will be continued assurance that loads may continue to be supplied by a source with adequate voltage. In addition, monitoring of the grid condition via the predictor model will provide a means to qualitatively gauge risk during plant operation so that actions or contingencies may be effected. Therefore, the proposed change does not involve a significant increase in the probability of an accident previously evaluated. On the basis that

{ immediate power availability can still be assumed, the proposed change also does j not significantly increase the consequences of any accident previously evaluated.

i (2) "Ihe proposed change effectively only involves or impacts offsite source availability. The most severe impact of the proposed change is therefore bounded j

by the loss of offsite power event, and therefore, the proposed change cannot j- create the possibility of a new or different kind of accident.

e (3) As noted previously, the proposed change does involve or permit intermittent i periods of time when one of the offsite sources may have inadequate voltage.

j This corresponds to intermittently making the source a delayed source. Compared j to the currently accepted licensing basis wherein the offsite sources are both j immediate access sources, there is a reduction in the margin of safety.

However, this reduction in margin is not considered to be significant considering j

the fact that the proposed change allows a source configuration that still meets the underlying purpose of GDC 17, and then, only for limited and intennittent periods j

of time. In addition, the periods ofpeak load demand (which drive a source to

,. effectively become a delayed source) will diminish when cooler weather retums.

! The proposed change is temporary on the basis that it wid only be effective up to j and including October 15,1997.

j Based on the foregoing, IP concludes that the proposed change does not involve a

'i significant hamds consideration.

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i j Anachment 2 to U 602XXX I

DRAFT AdditionalInformation

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In accordance with 10CFR50.12(a), the NRC may grant exemptions from the requirements of the regulations when special circumstances, as dermed in

10CFR50.12(aX2), are present. 10CFR50.12(aX2Xii) states that special circumstances

! exist when application of the regulation in the particular circumstances would not serve the underlying purpose of the rule ar is not necessary to achieve the underlying purpose j of the rule. In accordance with 10CFR50.12(aX2Xiii), special circumstances exist when compliance with the regulation would susult in undue hardship or other costs that are j significantly in excess of those contemplated when incurred by others similarly situated.

In addition,10CFR50.12(aX2Xv) states that spccial circumstances exist when the i

exemption would provide only temporary relief from the applicable regulation and the j licensee or applicant has made good faith efforts to comply with the regulation.

i l The purpose of GDC 17 is to provide criteria for the design of the onsite and j offsite electrical distribution systems such that they c'a n each reliably fulfill their safety i-I functions (assuming the other system is not functioning) of pmviding sufficient capacity l and capability to assure that: (1) specified acceptable fuel design limits and design i conditions of the reactor coolant pressure boundary are not exceeded as a result of

} anticipated operational occurrences, and (2) the core is cooled and containment integrity and other vital functions are maintained in the event ofpostulated accidents. As l

! described earlier, changing the classification of one of the two offsite power circuits to i " delayed access" when it is experiencing less-than-adequate voltage, although similar to a l source with " delayed access" as permitted by ODC 17, cannot be strictly regarded as i

such. Nevertheless, since the changes proposed by IP still provide for two physically independent offsite sources with sufficient capacity and capability (albeit, one immediate  !

and one delayed by means ofload shedding) to accomplish their safety function, bases are maintained whereby underlying purpose of ODC 17 is still served. Based on these criteria, IP requests a temporary partial exemption from the requirements of 10CFR50 Appendix A GDC 17.

j Reauest for NRC Review and Anoroval on an Rmarnency Basin (ner 10CFR50.91(aVST) l Under certain circumstances, as provided by 10 CFR 50.91, NRC review and approval of a proposed license amendment can be expedited where failure to act in a l 1 timely manner would result in prevention or resumption ofplant operation. Given that CPS is scheduled to restart from the current refueling outage on July 28,1997, the j processing of this license amendment application by the nonnal process would significantly delay plant startup. Therefore, pursuant to 10 CFR 50.91(aX5), IP requests 4

that this application for amendment be processed on an emergency basis. l

As explained previously, failure of the plant modification fo'r installing regulating j voltage transformers resulted in the need to make adjustments and changes to the existing j auxiliary power system during the current refbeling outage without the intended voltage j

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07/21/97~ '15:54' ~ CPS *L1CENSINGT 130141'53061 h0.318 D15 Attachment 2 to U-6o2XXX DRAFT *=

regulation. The extensive calculations required to support the auxiliary power system changes and to determine the plant voltage requirements based on the critical plant loads were not completed until later in the outage. Monitoring of the offsite voltages and use of the aforementioned predictive model were initiated after completion of the calculations.

Further, it has only recently become apparent that IP will not be able to maintain voltage levels on the 345-kV bus above the level required by CPS 100 percent of the time. As also explained previously, this is based in part on the unusual, cunent unavailability of generators in the region and high load demands currently being experienced during peak summer hours. These conditions and the need for this requested amendment were thus unforeseen. On this basis, and given that the proposed amendment involves no significant hazards consideration and is needed to proceed with plant startup in the near a

future, IP believes that there is a need and justification for processing the proposed amendment on an emergency basis.

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• LICENSING + 13014153061 NO.318 D16 Attachment 3

. to U-602XXX LS-97 004 Page 1 of X 4

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-S-  % z.w (8) Post-Fuel Loadina Initial Test Proaram (Section 14. SER. SSER 5 l and SSER 61 a

i' Any changes to the initial test program described in Section 14 of the FSAR made in accordance with the provisions of 10 CFR 50.59

shall be reported in accordance with 50.59(b) within one month of l such change.

[ (9) Emepency Resoonse Canabi' ities (Geisarie Letter 82-33. Sunn' er.ent I

! to NUREG-0737. Section 7.!i.3.1. SSET 5 and SSER 8. and Sectoon 18.

SER. $$ER 5 and Safety Evaluation Dated Anr11 17 1987) i

{ a. IP in accordance with the committment contained in a letter

! dated December 11, 1986, si.all install and have operational i separate power sources for each of the fuel zone. level

cha~nnels as provided for in Regulatory Guide 1.97 prior to l startup following the first refueling outage.

j b. IP shall submit a detailed control room design fWal supple-

mental summary report within 90 days of issuance of the full power license that enepletes all the remaining items identified in Section 18.3 of the Safety Evaluation dated l April 17, 1987.

! D. The facility requines' exemptions from certain requirements of 10 CFR 3 Part 50 and to CFR Part 70. These include: (a) an exemption.from the t requirements of 10 CFR 70.24 for the criticality alans monitors around

the fuel-storagearea; (b) an exemption from the requirement cf 10 CFR

Part 50, Appendix J - Option 8, paragraph III.B. exempting the measured

?eakate rates from the main steam isolation valves from inclusion. in the

! y . "7 'S ined '.nak rate for local leak rate tests (Section 6.2.6 of SSER 6);

! (c) an exemption from the requirements of paragraph III.8 of Option l

! f 10 CFR Part 50, Appendix J exempting leakage from the valve

, packing and the body-to-bonnet seal of valye IE51-F374 associated with l containment penetration INC-44 from inclusion in the combined leakage

! rate for penetrations and valves subject to Type 8 and C tests (SER i j supporting Amendment 62 to Facility Operating License No. .NPF-62). The I special circumstances regarding each exemption, except for Item (a) above, are identified in the referenced section of the safety evaluation report and the supplements thereto. -

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• 13014153(El NO.318 D18 Attachment 3 to U-602XXX m

DRAFT Insert A 3

and (d) a temporary partial exemption fmm tt

.e requimments of 10 CFR Part 50, Appendix A, General Desica Criterion 17 to allow plant operatior. while one of the two independent offsite electrical circuits is experencing intermittent (but quickly recoverable) periods ofless-than-adequate voltage (SER supporting Amendment 115 to 4-Facility Operating License No. NPF-62) 5 l

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Attachment 4 j to U-602XXX i DRAFT = AC Sources-Operating l

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3.8.1 l l

3.8 ELECTRICAL POWER SYSTEMS 3.8.1 AC Sources-Operating 1

i LCO 3.8.1 The following AC electrical power sources shall bc OPERABLE:

NOTE Onc off-site source may be a " delayed necess" source in accordance with the exemeption i to 10CFR50 App. A Criterion 17, provided within Operating License Amendment !!5. l

a. Two qualified circuits between the offsite transminion network and the onsite Class lE AC Electric Power Distribution System; and

b. Three diesel generators (dos).

APPLICABILITY: MODES 1,2, and 3.

I NOTE-Division 3 AC electrical power sources are not required to be OPERABLE when High Pressure Core Spray System is inoperable.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One offsite circuit A.1 Perform SR 3.8.1.1 for OPERA 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> inopesable, offsite circuit. AN,p, Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thercafter M

A.2 Restors offsite circuit 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> OPERABLE status.

AHl2 6 days from discovery of failure to meet LCO (coottaued)

CLINTON 3.8-1 AM-t No. 95

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07/2'1/97 15:56 CPS *LICENSh[G A 13014153061 NO.318 D21 i Attachment 5 to U.602XXX DRAFT ,

LS97-004 Page1of4 i

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• 13014153061 NO.318 D22 Aanchment 5 w U-602XXX DRAFT ==

AC Sources-Operating B3.8.1 i

BASES (continued)

I LCO Two qualified circuits between the offsite transmission network and the onsite Class 1E Distribution System and three separate and independent dos (I A, IB, and IC),

4 ensure availability of the required power to shut down the reactor and maintain it in a safe i

shutdown condition afb an anticipated operational occurrence (AOO) or a postulated j DBA.

i Qualified offsite circuits are those that are described in the USAR and are part of l the licensing basis for the unit.

' Each offsite circuit must be capable ofmaintaining rated frequency and voltage, and accepting required loads during an accident, while connected to the ESF buses. Each offsite circuit consists ofincoming breaker and disconnect to the respective reserve auxiliary transformer (RAT) or emergency reserve auxiliary transformer (ERAT) and the respective circuit path including feeder breakers to each of the 4.16 kV ESF buses.

, Insert A Each DO must be capable of starting, accelerating to rated speed and voltage, and connecting to its respective ESF bus on detection of bus undervoltage. 'Ihis sequence must be accomplished within 12 seconds. Each DO must also 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 ESF buses. These capabilities are required to be met from a variety ofinitial conditions such as DO in standby with engine hot and DO in standby with engine at ambient conditions. Additional DO 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 sequencing of loads, including tripping of nonessential loads, is a required l function for DO 1 A and DO IB OPERABILITY.  !

The AC sources in one division must be separate and independent (to the extent possible) of the AC sources in the other division (s). For the dos, the separation and l independence are complete. For the offsite AC sources, the separation and independence

' l are to the extent practical.  ;

_ (continued)

CLINTON B 3.8-3 Revision No.

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0741m 15:57 CPS *LICENS1tG -.13014153061 to.318 p23 Anachment 5 i to U-602XXX DF,MFT  :=

In accordance with Amendment 115 to the CPS Operating License, issued in response to IP's application dated July 21,1997 (IP letter U-602XXX), for a temporary partial exemption from General Design Criterion 17 of 10CFR50 Appendix A and corresponding license amendment concerning plant operation with an offsite source having less than adequate voltage, either of the offsite circuits may be considered a

" delayed access" circuit during such periods while Amendment 115 is in effect.

Acceptable voltages for the offsite circuits are based on actual voltage levels or a predictive model established to estimate, under various conditions, what the transmission source voltage should be in the event of a plant trip since such voltages are normally supported to higher levels with the plant on line. An offsite source with less than acceptable voluge based on actual voltage levels or the predictive model is regarded as a

" delayed access" source on the basis that measures can be taken to quicidy recover voltage.

While Amendment 115 is in effect, the following actions are required to be taken in the event that voltage on one or both offsite sources is less than acceptable based on the actual voltage level or as determined by the predictive model:

(1) With inadequate voltage for one source during normal plant operation, plant operators shall coordinate with the IP Dispatch Center to be prepared to take measures to restore supply voltage. Mode changes are pennitted with inadequate voltage for one source.

1 (2) With inadequate voltage for both sources during normal plant operation, the Required Actions for Condition A under TS 3.8.1 shall be entered. Plant

' startup is not permitted with inadequate voltage on both offsite circuits.

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07/21/97 15:5b CPS *tdCENSING 13014153061 NO.318 D24 i Attachment 5 q

! , to U 602XXX t DRAFT  := I SURVEILLANCE Diesel Generator Test Schedule (continued) i REQUIREMENTS

> A test interval in excess of 7 days (or 31 days, as appropriate) constitutes a failure to meet SRs and results in the associated DO being declared inoperable. It does not, however, constitute a valid test or failure of the DO, and any consecutive test count is not reset.

REFERENCES 1. 10 CFR 50, Appendix A,GDC 17.

l 2. USAR, Chapter 8.

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3. Regulatory Guide 1.9. .

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4. USAR, Chapter 6.

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5. USAR, Chapter 15.

6. Regulatory Guide 1.93.

7. Generic letter 84-15, July 2,1984.

8. 10 CFR 50, Appendix A, GDC 18.

9. Regulatory Guide 1.108, 10$ Regulatory Guide 1.137.

11. ANSI C84.1,1982.

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12. NUMARC 87-00, Revision 1, August 1991.

13. IEEE Standard 308.

14. IP Calculation 19 AN-19.

15. IP calculaC,n 19 AQ-02.

16. NRC SEK forIP Operating License Amendment 115.

l CLINTON B 3.8-32 Revision No.

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07/21/97 15:58 CPS

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• 13014153061 NO.318 D25 Attachment 6 to U-602XXX DRAFT

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Attached Environmental Assessment 1

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Attachment 6 to U.602XXX DRAFT =x i Environmental Meanment IP's request is based on granting a temporary partial exemption from the requirements d

contained in General Design Criterion 17 " Electric Power Systems," of Appendix A to

10 CFR 50. Pursuant to the provisions of 10 CFR 50.34, an application for a construction

permit must include the principal design criteria for a proposed facility. With I consideration and flexibility given to variations in design, siting and environmental

, conditions, the General Design Criteria of Appendix A to 10 CFR 50 establish minimum I requirements for the principal design criteria for water-cooled nuclear power plants. )

Licensing of Clinton Power Station (CPS) was based, in part, on the NRC's evaluation I of the CPS design as it conforms to the General Design Criteria. The NRC's review,  !

evaluation and acceptance of the design for the electric power system at CPS, as described in the CPS Final Safety Analysis Report, was documented in the CPS Safety

)

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Evaluation Report (NUREG 0853) issued to support licensing of the facility.

Conformance of the design for the CPS onsite and offsite electric power systems is documented in the Safety Evaluation Report. IP's request to temporarily allow plant operation with one of the two offsite sources intermittently having voltage that is less the minimum value conservatively established for CPS, would establish an operating

! configuration that in not strictly in conformance with GDC 17, Speci5cally, an offsite source with voltage intermittently less than required, does not constitute a source having

" sufficient capacity and capability" as required by GDC 17. Consequently, an exemption is required from the requirement of GDC 17 stating,"The safety function for each...."

The Need for the Proposed License Amendment and Exemotion i

The proposed amendment and exemption is needed since strict application of the l requirements of GDC 17 of Appendix A to 10 CFR 50, regarding the requirement for the offsite electric power system to have suficient capacity and capability, is not necessary to achieve the underlying purpose of the rule and would impose undue hardships to IP, 1

Strict conformance to GDC 17 requires that the offsite source experiencing intennittent low voltages have sufficient espacity and capability such that voltage is maintained, on a continuous basis, above the minimum value coaservatively established l

for CPS. IP has determined that all practical measures taken to boost voltage, short of interrupting service to customers, are not sufficient to maintain the minimum required voltage. Further action to restore voltage would necessitate power interruptions.

07/21/97 15:59 CPG

• LICENSING -* 13014153061 NO.318 D27 Anschtnent 6 to U-602XXX DRAFT LS97-004 Page 3 of X In response to the intermittent voltage condition for the 345-k'Vsystem due to the unusual conditions existing in the Illinois region this summer, IP has implemented measures to assess when the 345-kV system voltage would be inadequate in the event of a plant trip, has performed an analysis to assess the risk associated with continued plant operation for the period of time within which the intermittent condition is likely to occur (i.e., until this fall), and has established (by practice) a reasonable recovery time to restore bus voltage in the event that it is needed (assuming a loss of the other offsite source).

Without the exemption, the offsite source experiencing intermittent periods oflower than expected voltage would have to be considered inoperable. Plant startup or continued plant operation is not permitted with one offsite source inoperable.

Environmental Imoacts of the Prooosed Amendment and Exemntion Granting the exemption and license amendment would not significantly increase the probability of unavailable offsite power in the event of an accident, and therefore, would not significantly increase the probability of a radiological release from CPS. The availability and reliability of the onsite power sources would not be affected by the exemption / amendment. The availability and reliability of the offsite source having adequate voltage would also not be affected. Although there is a slight increase in the probability of having the low-voltage offsite source unavailable following a plant trip, or both sources unavailable in the event of a loss of the other offsite source, this increase is small based on the factors identified, and actions taken or that can be taken, by IP. On the assumption that electric power would still be available for safety-related equipment i required to mitigate an accident, the proposed change does not involve an increase in the consequences of an accident.

With regard to potential nonradiological impacts, the proposed exemption / amendment would not affect the operation of the facility on the basis that adequate electric power will still be available to the facility during accident conditions, and particularly, during normal operation. With no impact on plant operation, the proposed change does not impact nonradiological effluents and has no other environmental impact. With regard to IP's customers, the intent of the exemption / amendment is to permit continued plant operation, which will support grid voltage, without intermpting service to IP's customers, the latter of which could potentially have environmental and public safety impacts.

Alternative to the Proposed Action Given that there are no significant environmental effects associated with the proposed exemption / amendment beyond those attributed to operation of the facility, any altematives (except to not allow operation of the facility) would have no greater, favorable environmental impact..

The principal altemative would be to deny the requested exemption / amendment. This would effectively preclude operation of the facility until the intermittent voltage condition is resolved. Notwithstanding, IP has provided justification to support safe

0741G 16100 CPS *L1CENS1NG

• 13014153061 NO.318 D28 Attachment 6 to 0402XXX DRAFT

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i startup and operation of CPS. On the basis diat safe plant operation is justified, and the fact that strictly imposing GDC 17 would not allow plant operation, the cost j

associated with strict compliance with GDC 17 is notjustified, particularly with respect i

to any environmentalimpact.

Altemative Use of Resouregg i

The proposed amendment / exemption does not involve the use of any resources not previously considered in the " Final Environmental Statement Related to the Ope

' Clinton Power Station, Unit 1," dated May 1982.

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