ML20205Q947

Application for Amend to License NPF-39,changing Tech Specs to Permit Operation of Reactor W/One of Two Reactor Circulation Loops in Svc

ML20205Q947
Person / Time
Site:	Limerick
Issue date:	11/04/1988
From:	Bradley E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
Shared Package
ML19297H235	List: ML20205Q926 ML20205Q947 ML20205Q974
References
NUDOCS 8811090406
Download: ML20205Q947 (41)

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BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION In the Matter of a

Docket No. 50-352 PHILADELPHIA ELECTRIC COMPANY APPLICATICA FOR AMENDMENT OP FACILITY OPERATING LICENSE NPF-39 Eugene J. Bradley 2301 Market Street Philadelphia, Pennsylvania 19101 Attorney for Philadelphia Electric Company ss11090406 881104 PDR ADOCK 05000352 p PDC

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5 BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION In the Matter of a

Docket No. 50-352 PillLADELPill A ELECTRIC COMPANY APPLICATION FOH AMENDMCNT OF FACILITY OPERATING LICENSE NPF-39 i

Philadelphia Electric Company, Licennee under Facility a

Operating License NPF-39 tor Limerick Generating Station Unit 1, hereby requents that the Technical Specifications contained in Appendix A of the operating License be amended. The proposed changes are indicated by vertical bara in the margin of the 1 attached pages 2-1, 2-4, 3/4 2-1, 3/4 2-7, 3/4 2-10, 3/4 2-10a,

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3/4 3-60, 3/4 3-60a, 3/4 4-1, 3/4 4-la, 3/4 4-2, 3/4 4-3, 3/4 4-4, 3/4 4-448, 3/4 4-5, B2-1, il 3/4 1-2, H 3/4 2-1, H 3/4 2-2, B 3/4 2-4 and il 3/4 4-1.

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Licensee requests these changes in order to permit operation of the reactor with one of two reactor recirculation loops in service.

Technical Specification 3.4.1.1 Action currently statec "hith one reactor coolant system recirculation loop not in operation, inmediately init iate action to reduce THERMAL POWER. . .

within two hours and initiate measures to place the unit in at lesst flOT SiluTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> ..." The proposed changes would allow reactor operation with one recirculat!on loop, at reouced power for significant periods of time, withou' the need to remove the reactor from service.

Thiu application is formatted to define and justify the requested changes by presenting a description of Single Loop Operation, a description of the proposed page changes, a safety assessment of t7.e proposed changes, a justification for no signiricant nazards consideration determination, ans an environmental conuideration.

Discusaton Single I,oop operation (SLO) is the operation of a reactor with only one recirculation loop in nervice. The use of St,0 provides a great deal of operational flexibility and serves as a mechanism to avoid the unnecessary removal of a reactor from service with the attendant cycling of reactor components in the event a recirculation pump or other component malfunction renders one recirculation loop inoperable. During SLO, the core pressure

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4 drop is reduced and the total dischdr9c flow from the active bank of jet pumps increases at rated drive flow. Plow through the t inactive jet pumps reverses direction and the flow pattern in the '

reactor lower plenum becomes asymmetric relative to rated <

conditions with balanced two-loop inlet flow. SLO is a l i

recognized practice for boiling water reactors that has been i previously accepted and licensed by the Nuclear Negulatory f L

l Commission at various facilities including Peach Botton Atomic l l

Power Station, Hope Creek Generating Station, Susquehanna Steam t

Electric Station and Browns Ferry Nuclear Station. The NHC has j i determined that SLO of BWR's is generically acceptable as set i

forth in Generic Letter No. 86-09, "Technical Resolution of f

Generic lanue No. B-59-(N-1) loop operation in BWHs and PWRs,"

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dated March 31, 19b6. .

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The analysis of the safety considerations involved in f

SLO of Limerick Generating Station Unit 1 is uet fort.h in General [

4 l Elect ric company Document No. NEDC-31300-P, "Single-Loop f Operation Analysis for Limerick Generating Station Unit 1," dated l 4

October 1988, which la filed herewith and incorporated by reference. This document contains information which General Electric company wishes to maintain in confidence and to be [

I withheld from public disclosure. This information has been  ;

handlea and clasulfied as proprietary to General Electric l l

Compary, au indicated by the attached affidavit of Rudolph Villa, (

Manager, Consulting Services of General Electric Company.

Therefore, Licensee hereby requests that this document be withheld t~ rom public disclosure in accordance with the provisions I

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of 10 CPR 2.790. The design basis accidents and abnormal operational transients associated with power operation, as presented in the Limerick Final Safety Analyais Report, Sections 6.2 and 6.3, and the main text of Chapter 15.0 have been reviewed for unit operation with only one recirculation loop in service.

The transient safety analysis was performed on an initial cycle basis connistent with that for the PSAR. The analysis shows that the trannient consequences for SLO are bounded by the full power two loop operation analysis results given in the FSAR. The conclusion drawn from the transient analysis results is applicable to reload cycle operation as well as initial cycle operation for 14S as detailed in NEDC-31300-P.

Operating with one recirculation loop results in a maximum power output approximately 304 below that which is attainable for two-pump operation. Therefore, the consequences of abnormal operational transients from one-loop operation will be considerably less severe than those analysed for two-loop operation. For pressurization, flow increase, flow decrease, and cold water injection transients, the results presented in Chapter 15 of the LGS FSAR for two-pump operation bound both the thermal and overpressure consequences Of SLO.

1 The !.oss of Coolant Accident (IDCA) analysis presented in LCS FSAR Section 15.6 has been evaluated for SLO and la presented in NCDC-31300-P. The evaluation utilized the GE methodology outilned in NEDO-20S66-2, Revision 1, "General Electric Company Analytical Model for Loss-of-Coolant Analysis in Accordance with 10CPR50 Appendix X Amendment No. 2 - One Recirculation Loop Out-of-Service", dated July, 1978.

NEDC-31300-P also presents the results of certain other

[ analyses, the consequences of which are bounded by previously uubmitted full power two loop operation analyses. These include MCPR operating limit, containment analysis, ATWS and fuel meenanical performance. Consequently, no changes to the Tecnnical Specifications addressing thene areas are proposed based on the results of these analyses.

Proposed Page changes The proposed changes on Page 2-1 raide the Safety Limit Minimum Critical Power Ratio (MCPR) by 0.01 to account for increased uncertainties in the core total flow and Traversing In-Core Probe (TIP) readings during SLO.

The proposed changes on Pages 2-4, 1/4 2-7, 3/4 3-60, and 3/4 3-604 provide individual Average Power itange Monitor (APRM) ucram and rod block equations and Rod Block Monitor (RBM) rod block equations for two loop operation and SLO to account for the discrepancy between actual core flow and indicated flow in the active loop during SLO.

The proposed change on Page 3/4 2-1 incorporates a Maximum Average Planar Linear lleat Generation Rate (MAPLilGR) reduction factor of 0.89 for SLO. The MAPLHGR reduction factor accounts for core flow decreasing more rapidly during a LOCA in

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SLO than two-loop operation which could result in more severe heatup of fuel cladding.

The proposed changes on Pages 3/4 4-1 through 3/4 4-2 incorporate action statements and associated surveillance requirements to ensure SLO is conducted within the analyzed bases. In addition to the previously mentioned MCPR, MAPLHGR, APRM and HBM changes, this specification restricts SLO to manual f flow control, limits thermal power to less than or equal to 70%

of rated, limits operating recirculation pump speed to less than or equal to 90% of rated, and establishes thermal hydraulic [

stability and differential temperature requirements.

l The proposed changes to Piqure 3.4. l.1-1 Thermal Power Veruus Core Plow on page 3/4 4-3 define the unrestricted and restricted operating regions of the percentage rated core thermal i i

power versus percentage rated core flow curves.  !

l l The proposed changes on Page 3/4 4-4 and 3/4 4-4a j establish jet pump operability Surveillance Hequirements for SLO.

In addition, changes are proposed on Page 3/4 2-7 to j delete an ambiguous phrase in the note; on Pages 3/4 2-10 and 3/4 f 2-10a to provide notes to clarify the applicability of MCPR operating limitn; on Page 3/4 4-5 to clarify the recirculation f f

loop clow miumatch Action requirements; and on Pages H2-1. H 3/4 L l

l l-2, D 3/4 2-1, H 3/4 2-2, H 3/4 2-4 and B 3/4 4-1 to incorporate [

the results of SLO analyses in the Bases, f

Safety Assessment r

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o' A safety assessment of each proposed change follows:

A. MCPR Safety Limit for SLO The uafety limit MCPR is set such that no fuel damage is calculated to occur if the limit is not violated. It is determined using the NRC approved General Electric BWR Thermal Analysis Basis (GETAB) NEDO-10958A dated January 1977, which is a statistical model tnat combines uncertainties in the methods used to calculato critical power. Except for core total flow and TIP reading, the uncertainties used in the statistical analysis to determine the MCPR fuel cladding integrity safety limit are not dependent on whether coolant flow is provided by one or two recirculation pumps.

For SLO, the uncertainties in total core flow and TIP readings used in the determination of the safety limit MCPR are larger than for two-loop operation. These two uncertainties are analyzed in NEDC-31300-P and provide a net effect of 0.01 increase in the safety limit MCPH to 1.08.

The current MCPH operating limit and flow-dependent MCPR limit provide adequate protection for transients initiated during SLO. The results of the analyses of these events show sufficient margin to the proposed increased MCPR fuel cladding integrity safety limit. The consequences of abnorsal operational transients during single loop operation are less severe than those analyzed for two-loop operation due to reduced maximum power output. Por pressurization, flow increase, flow decrease, t

and cold water injection transients, the results presented in

! Chapter 15 of the 14S PSAR bound both the thermal and overpressure consequences of SLO. These abnormal operational 1

1 transie.its are discussed below.

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The two most limiting pressurization transients analyzed for SLO are Feedwater Centroller Pallure - Maximum Demand (PWCP) and Generator Load Rejection with Hypass Pailure (LRHPP). The results of these two analyses are presented in NEDC-31300 Table 3-4. The PWCP event la postulated on the basis of a single failure of a master feedwatnr control device, specifically one which can directly cause an increase in coolant inventory by increasing the total feedwater flow. The most severe applicable event is a feedwater controller failure during maximum flow demand. The calculated transient MCPR of 1.20 for SLO is much greater than the current safety limit of 1.07 and the proposed l limit ot 1.08. The resulting peak vessel pressure of 1113 psig is much lower than the ASME limit of 1375 psig.

The LRDPP event, which is the loss of generator electrical load t ros high 12cwer conditions with f ailure of the main tutbine bypass valves, is discussed in PSAR Section 15.2.2.

The calculated transient MCPR of 1.18 for Si,0 is much greater than the current safety limit 1.07 and the proposed limit of 1.08. Tne resulting peak vessel pressure of 1182 psig is much lower than the ASME limit of 1375 psig.

The consequences of flow increase and flow decrease transients during SLO are bounded by the full power analyses presented in LCS FSAR Sections 15.4 and 15.1. The worst flow increase transient results from a recirculation flow controller failure. The flow and power increase associated with a single flow controller failure during SLO will be leas than that associated with the failure of both flow controllers during two loop operation.

The consequences of flow decrease from a single pump trip during SLO is less severe than a ts) pump trip from full power as discussed in FSAR Section 15.3.1 because of the reduced initial power level. The consequences of flow decrease resulting from a recirculation pump seizure accident has been analyzed and found acceptable with consideration for both two-loop and one-loop operation. This accident analysis is dincussed in FSAR l Section 15.3.3 and presented in subsection S.2.5.5 of GESTAR II, 1 NEDE-24011.

The most severe cold water injection event with respect i to increase in core power is loss of feedwater heating. A generic statistical loss of feedwater heater analysis (referenced l in NEDC-31300-P) using different initial power levels and other core design parameters concluded that SLO with lower initial power level is conservatively bounded by the full power two-pump analysis such that the MCPR safety limit le not violated.

H. Cotrection of RBM and APRM Plow-Biased Setpoint Equations

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The recirculrit.;rm ). - rate dependent Rod Block Monitor (RBM) rod block trip .-ut .. .ad Average power Range Monitor (APRM) rod block and t :n ..n 6Ap setpoint equations given in the Limerick Technical Specifications will be conuervatively modified for the proposed single loop operation. SLO results in backflow through 10 of the 20 jet pumps such that the direct active-loop flow measurement may not indicate actual flow above about 40%

core flow without correction. The equations would be adjusted to account for the discrepancy between actual flow and indicated flow in the active loop. The purpose of the RBM is to prevent withdrawal of a control rod beyond the point where fuel damage is expected to occur. An analysis of rod withdrawal error at rated power with two loop operation is presented in PSAR Section 15.4.2. Single loop operation results in lower power levels than analyzed for the Rod Withdrawal Error Accident. The lower power level coupled with the modification of the RBM rod block equation assures that the MCPR safety limit is not violated as a result of i a rod withdrawal error. The purpose of the APRM scram and rod block equations is to prevent fuel damage in the event of an unanticipated power transient. APRM trip setpoints are flow I

biased in the same manner as the RHM rod block trip setpoint. As with the RDM, the modification of the trip setpoint equation coupled with lower power levels during SLO asoures that the MCPR safety limit is not violated. Furthermore, no credit is taken in the safety analyses for flow biased reduction of the APRM scram and rod block setpoints.

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C. MAPLiiGR Reduction Factor MAPLilGR Limits are established to ensure that the acceptance criteria for fuel and Emergency Core Cooling systems (ECCS) established in 10CPR 50.46 are met. For SLO, in the event of a LOCA, the core flow decreases more rapidly than in the two-loop operating case, resulting in more severe cladding heatup.

SLO would also result in small changes in the high power node uncovery timoa of rated spray. The effect ot the reflooding timen for various break sizen is also generally small. A SLO LOCA analynia was performed for LGS using the models and aasumptions documented in General Ulectric Document NEDO-20566-2 Revision 1 "General Electric Company Analytical Model for Loss-ot-Coolant Analysis in Accordance with 10CFR50 Appendix K Amendment No. 2 - One Recirculation Loop Out-of-Service" dated July 1978. Using this method, SAFE /REFLOOD computer code runs were made for a full spectrum of large break uizes for only the recitculation auction line breaks (most limiting for LGS). The total hot node uncovered time (time between uncovery and reflood) for two-loop operation is 133.8 seconds for the 100% DBA suction break. For SLO the total uncovered time is 134.3 seconds for the 1001 DBA suction break. A small break LOCA would cause a slight increase (50 degrees P) in the peak cladding temperature (PCT).

This increase would be oftset by the reduced KAPLliGR used during SLO, resulting in PCT values less than the 1550 degrees P small break PCT value previously reported for LGS, and significantly lower than the 10CPR50.46 cladding temperature limit of 2200 degrees P. Because the reflood minus uncovery time for the SLO r

l aaalysis is similar to the two-loop analysis, the maximum planar .

linear heat generation rate (MAPLHGR) curves can be modified by '

derived reduction factors for use during SLO. The results of an analysis performed to determine the MAPLHCR reduction factor for i

Cycle 2 fuel are set forth in General Electric Company Document No. 23A5801, "Supplemental Reload Licensing Submittal for i

Limerick Generating Station Unit 1, Reload I," dated February i 19H7, which is incorporated herein by reference. I i

D. Thermal Power Limitation

{r The analyaes for SLO presented in NEDC-31300-P assume j 75% rated thermal power and 60% tated core Clow, which represent.s I f

single recirculation loop operation at 100% pump speed on the [

1051 rod line.

l The range ei oower/ flow conditions in the SLO operating f domain for LCS have been evaluated and determined to be within  !

I the range ot~ operating conditions which have previously been l t

conradered in determining the containment prensure and tamperature response and containment dynamic loads for two-loop [

f operation. The impact of SLO on containment response is bounded i e

by the containment design basis present in PSAR Section 6.2.1. {

The effect of SLO on Anticipated Transient Withcut Scram (ATWS) performance was evaluated. "he transient response during SLO la less nevere than during two 1 op operation because the initial power / flow condition is lower.

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II. Recirculation Pump _ Speed Limitation The recirculation pump speed will be limited to 90% of rated during SLO. SLO vibration tests conducted at Browns Ferry 1 (the Limerick prototype plant) and Peach Botton 2 and 3 deronstratOd that all instrumented vessel internal component vibrations are within the allowable criteria. However, due to

':he high vibration levels recorded, Browns Ferry and Peach Bottom have conservatively limited SLO recirculation pump speed to 90%

of rated. Results of the aforementioned analyses and tests show that under all SLO operating conditions the vibration level is acceptable; therefore, operation at 90% rated recirculation pump speed is bounded by previously submitted full power analyses.

! P. Stability Requirements l

l The proposed revisions regarding APRM and LPRM noise l

l levels are an addition to the current stability provisions to implentet the NRC approved stability criteria (GE Co. SIL-380, Revision 1) for SLO as set forth by Generic Letter 86-02, dated January 23, 1986 and Generic Letter 86-09 dated March 31, 1986.

Thntmal-hydraulic stability during SLO was generically evaluated in the General Electric report NEDE-240ll, Rev. 6, Amendment 8 "Thermal Hydraulic Stability Amenduent to GESTAR II", dated April 24, 1985 and tound to satisfy the requirements of 10CPR50, Appendix A. General Design Criterion 12. The high power / low flow cerner of the power / flow map, Pigure 3.4.1.1-1 on page 3/4 4-3, is the region of least stability margin. Operating in this

region requires increased stability monitoring. Stability monitoring provisions decrease the probability of fual damage by avoiding limit cycle neutron flux oscillations

'. Differential fesperature Requirements The proposed revisions for surveillance of recirculation loop differential temperature are an addition to the current requirements of Technical Specification 3.4.1.4 for idle recirculation loop startup. The purpose of the additional surveillance on differential temperatures below 30% thermal power or 50% rated recirculation loop flow is to mitigate undue thermal stress on vessel nozzles, recirculation pump and vessel bottom head during extended SLO. With thermal power and recirculation loop flow y' eater than the action levels, cold water will be adequately swept from the vessel bottom head, thus pre *;3nting stratification.

!! . Manual l' low Control To prevent potential control oscillations from occurring i

in the reilrculation flow control system, the operation mode of

• the recirculation flow control system will be restricted to operation in the manual control mode for SLO. Recirculation drive flow can be significantly noisier during SLO than during normal operation, resulting in a noisier signal to the scoop tube positioner. In the manual mode, the positioner flow demand signal will t>e constant between operator induced demand changes.

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1. Jet Pump Surveillance The proposed changes to the jet pump surveillance requirements provide clarification to specifically address SLO and two-loop operation. Significant increassa in APRM noise and core plate 6P fluctuation have been observed in some plants during operation at high flow rates while in SLO. The potential resultant vibrations could lead to mechanical failure of a jet pump. To assure this condition does not adversely affect jet pump performance, t'.te surveillance is incorporated for SLO.

J. Administrativt Changes Administrative changes are requested for pages 1/4 2-7, 3/4 2-10, 3/4 2 10a and 3/4 4~5 to provide clarification of the existing specifications. The proposed change to the note on page 3/4 2-7 deletes the reference to "power ascension" when adjusting the APRM setpoints by adjusting the APRM gain when the Maximum Praction of Limiting Power Density !MPLPD) is greater than the Praction of Hated Thermal Power (PRTP). The proposed change on Page 3/4 2-10 and 3/4 2-10a provides a note which identifies the MCPR versus T limits art. applicable to both two recirculation loop and single recirculation loop operation. The proposed change to the ACTION uf Technical Specification 3.4.1.3 on page 3/4 4-5 will require the shutdown of one of th( two recirculation loops within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> when recirculation flow mismatch exceeds the limit rather than declaring the loop of slower speed not in operation.

Significant Hazards Consideration Determination The NRC has provided guidance concerning the application of the utandards for determining whether license amendments involve no significant hazards considerations by providing examples (51PR7751). An example (iv)'of a change that involves no significant hazards consideration is a "relief granted upon demonstration of acceptable operation from an operating restriction that was imposed because acceptable operation was not yet demonstrated." The proposed revisions conform to this example since the current LGS Technical Specification Bases for 3/4 4.1 RECIRCULATION SYSTEM state, "cperation with one reactor core coolant recirculation loop inoperable lu prohibited until an evaluation of the performance of the ECCS during one loop operation has been performed, evaluated and determined to be acceptable."

The proposed Technical Specification changes for SLO will not increase the probability or consequences of any accident previously evaluated. The design basis accidents and abnormal operational transients associated with power operation, as presented in the LGS FSAR, Sections 6.2 and 6.3, and Chapter 15.0 have been reviewed for unit operation with only one recirculation loop in service. The appropriate setpo!ots and operating limits are adjusted for SLO and are bounded by tb2 LGS FSAR analysis performed for two-loop operation.

The proposed Technical Specification changes will not t create the ponnibility of a new or different accident from any

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previously evaluated. Although the proposed changes introduce'a new mode of operation, the possible accidents during SLO are the same as those analyzed in the PSAR for two-loop operation and are within the bounds of the LGS PSAR analysis.

The proposed Technical Specification changes will not involve a significant reduction in a margin of safety. The propcsed changes adjust t he appropriate setpoints and operating limits for SLO to maintain or improve the current margin of safety.

A no algnificant hazards consideration determination for each proposed change follows:

A. MCPR Safety and Operating Limit for SLO (1) The proposed increase in the MCPR fuel cladding integrity safety limit during SLO does not increase the probability or consequences of any accident previously evaluated.

The MCPR fuel cladding integrity safe y limit is set such that no tuel damage is calculated to occur if the limit is not violated. It is determined using the NP.C approved General Electric Thermal Analysis nisis (GETAD), which is a utatistical model that combines uncertainties in the methods used to calculate critical power. Por SLO, the uncertainties in total core flow and TIP readings used in the determination of the uafety limit MCPR are larger than for two-loop l

operation. NEDC-31300-P Section 2 analyzes the total core flow and TIP reading uncertainties for SLO. The net effect of these two revised uncertainties is a 0.01 incremental increase in the required MCPR fuel cladding integrity safety limit to a higher safety limit MCPR of 1.08 for SLO.

The current MCPR operating limit and flow-dependent MCPR limit provide adequate protection for transients initiated during SLO. The results of the analyses of these events show sufficient margin to the proposed increased MCPR fuel cladding integrity safety limit. The consequences of abnormal operational transients during single loop operation will be less severe than those analyzed for two-loop operation due to reduced maximum power output. Por pressurization, flow increase, flow decrease, and cold water injection transients, the results presented in Chapter 15 of the LGS PSAH bound both the thermal and overpressure consequences of SLO as discussed in the Safety Assessment Section of this application. The two most limiting pressurization transients analyzed for SLO are Feedwater Con..orler Pailure*- Maximum Demand (PWCP) and Genarator Load Hojection with Bypass Failure (LRUPP). The results of these two analyses are presented in NEDC sl300-P Table 3-4.

The PWCP event is pcstulated on the basis of a single failure of a master feedwater control device, specifically one which can directly cause an increase in coolant inventory by increasing the total feedwater flow. The most severe applicable event is a feedwater controller failure during

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maximum flow demand. The calculated tra,nsient MCPR of 1.20 for SLO is much greater than the current safety limit of 1.07 and the proposed limit of 1.08. The resulting peak vessel pressure of 1113 psig is rauch less than the ASME limit of 1375 psig. The LRBPP event which is the loss of generator electrical load from high power conditions with failure of the main turbine bypass valves is discussed in FSAR Section 15.2.2. The calculated transient MCPR of 1.18 for SLO is much greater than the currcnt safety limit 1.07 and the proposed limit of 1.08. The resulting peak vessel pressure of 1182 poig is much less than the ASME limit of 1375 psig.

The safety limit MCPR for SLO is set such that no fuel damage is calculated to occur and thereby accomplishes the same parpose as the two-loop operation limit. Because the revised higher safety limit of 1.08 maintains the current margin of safety and the current operating limit maintains sufficient margin to the revised safety limit, the change to the MCPR safety limit during SLO does riot increase the probability or consequences of any accident previously evaluated.

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(2) The proposed increase in the MCPR fuel cladding integrity safety limit during SLO does not create the possibility of a nes or different kind of accident from any accident previously evaluated.

The MCPR safety limit cannot initiate an accident and imposing the MCPR limit does not involve a char.ge in the current mode of-operation; therefore, this change does not create the possibility of a new or different kind of accident than previously evaluated.

(3) The proposed increase in the MCPR fuel cladding integrity safety limit during SLO does not involve a significant reduction in a margin of safety.

The MCPR safety limit is determined using NRC approved methodology. The proposed 0.01 increase accounts for the increased uncertainties in total core flow and TIP readings due to SLO. This increase in the MCPR safety limit maintains the margin of safety established for two-loop operation.

Therefore, this change does not involve a significant reduction in the margin of safety.

B. Correction of RBM and APRM Plow-Biased Setpoint Equations (1) The_ proposed changes to the RBM and APRM flow-blased setpoint equations do not increase the probability or consequences of any accident previously evaluated.

SLO results in backflow through 10 of the 20 jet pumps such that the direct active-loop flow measurement may not inditata actual flow above about 40% core flow without correction.

The proposed changes to the RBM and APRM flow-biased setpoint equations conservatively modify the recirculation flow rate dependent rod block and scram setpoint equations to correct

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for one pump. operation. .The proposed changes adjust the setpoint equations to preserve the original relationship between the setpoints and the effective drive flow when operating in SLO such that the consequences of a rod withdrawal error during SLO are bounded by the analysis presented in FSAR Section 15.4.2. Further, lower power during SLO assures that the MCPR operating limit is not violated. Therefore, the changes to the HBM and APRL1 flow-biased setpoint equations do not increase the probability or consequences of an accident previously evaluated.

(2) The pgoposed changes to the RBM and APRM flow-biased setpvint equations do not create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed changes correct the RBM and APRM flow-blased setpoint equations to preserve the original relationship between the setpoints and the actual effective drive flow when operating in SuO and therefore do not create the possibility of a new or different kind of accident than previously evaluated.

(3) The proposed changen to the RDM and APRM flow-blaued netpoint.,e_qua t ions do not involve a significan_t_

reduction in a inargin of safety.

.The proposed corrections to.the RBM and-APRM flow-biased setpoint equations preserve the original relationship between rod blocks and scram and actual effective drive flow during SLO; therefore, it follows that these changes do not involve a significant reduction in the margin of safety.

C. MAPLUGR Reduction Pactor (1) Application of the proposed MAPLUGF reduction factor during SLO does not increase the probalility_or, t

consequences of any accident previoun ty evaluated.

MAPLHGR Limits are established to ensure that the acceptance criteria for fuel and Emergency Core Cooling Systemu (6CCS) established in 10CFR 50.46 are met. Por SLO, in the event of a LOCA, the core flow decreases more rapidly than in the two-loop operating case, resulting in more severe cladding heatup. SLO would also result in small char.ges in the high-power node uncovery times and times of rated spray. The effect of the reflooding times for various break sizes is also generally small. A SLO LOCA analysis was performed for LGS uulng the models and assumptions documented in General Electric Document NEDO-20566-2 Revision 1, previously referenced. Using this method, SAFE /REPLOOD computer code runs were made for a full spectrum of large break sizes for only the recirculation auction line breaks (most limiting for LGS). The total hot node uncovered time for two-loop operation is 133.8 seconds. for the 1001 DBA suction break.

Por SLO the uncovered time is 114.3 seconds for the 100% DBA suction break. A small break LOCA would cause a slight increase (~ SO degrees P) in the PCT. This increase would be offset by the reduced MAPLliGR used during SLO, resulting in PCT values for small breaks less thar. the 1550 degree P small break PCT value previously reported for LGS, and significantly less than the 10 CPR 50.46 cladding temperature limit of 2200 degrees P. Since the reflood minus uncovery time for the SLO analysis is similar to the two-loop analyuis, the MAPLGIIR curves can be modified by derived reduction factors far use during SLO. The results of an analysis performed to determine the MAPLIIGR reduction factor for Cycle 2 fuel is set forth in General Electric Company Document No. 23A5801, "Supplemental Reload Licensing Submittal for Limerick Generating Station Unit 1, Heload 1,"

dated P oruary, 1987. The proposed MAPLHGR reduction factor is applied to ensure the consequences of a LOCA are not increased in SLO. Therefore, this change does not increase the probability or consequences of an accident previously analyzed (LOCA).

(2) Application of the proposed MAPLIIGR reduction factor during SLO does not create the possibility of a new or ditterent kind of accident from any accident _previously evaluated.

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MAPLHGR limits are established to ensure fuel integrity in the event of an accident. Modification of the MAPLHGR limit during SLO does not create the possibility of a new or different kind of accident than previously evaluated.

(3) Application of the proposed MAPLHGR reduction factor during SLO does not involve a significant reduction in a margin of safety.

The acceptance criteria of 10 CPR 50.46 cutablish the margins' of safety for fuel and ECCS. The analysis presented in NEDC-31300-P calculated the total hot node. uncovered time for the most limiting 100% DBA suction break to be 133.8 seconds for two loop operation and 134.3 seconds for single loop operation. The calculated small break peak cladding temperature (PCT) f r SLO would be less than the 1550 degrees F small break PCT reported for the two loop analysis. Since application of the conservatively calculated MAPLUGR reduction factor acts only to preserve the original relationship between two-loop MAPtHGRs and the acceptance criteria, this change does not involve a significant reduction in the margin of safety.

D. Thermal Power Limitation (1) Restricting operation in SLO to less than or equal to 70% rated thermal power does not increase the probability or consequences of any accident previously evaluated.

The analyses for SLO presented in NEDC-31300-P assume 75%

rated thermal power and 60% rated core flow, which represents single recirculation loop operation at 10Lt pump speed on the 105% rod line. All abnormal operational tra*.sients analyzed in the PSAR have been examined for effects caused by SLO.

The limiting abnormal operational transients have been re-evaluated in detail: generator load rejection with bypass failure and feedwater controller failure to maximum demand.

The impact of SLO on containment response, ATWS, and fuel thermal and mechanical performance was also evaluated.

Consequences of all these were foand to be bounded by previously submitted full power analyses. Therefore, restricting operation in FLO to less than or equal to 70%

rated thermal power does not increase the probability or consequences of an accident previously analyzed.

(2) Hestricting_ operation in SLO to less than or equal to 70% rated thermal power aoss not create the possibility of_a new or different kind of accident from any accident previously evaluated.

The range 5)f powec/ flow conditions in the SLO operating domain has been evaluated and found to be within the previously evaluated range of operating conditions. SLO only

changes the assumptions utilized in the appropriate previous analyses and therefore, does not' create the possibility of a new or different kind of accident than previously evaluated.

(3) Restricting operation in SLO to less than or equal to 70% rated thermal power does not involve a significant reduction in a margin of safety.

Results of the aforementioned analyses show that SLO at 75%

rated thermal power is bounded by previously submitted full power analyses. Therefore, limiting SLO to less than or equal to 70% rated thermal power (which corresponds to 90%

rated pump speed) does not involve a significant reduction in the margin of safety.

E. Hecirculation Pump Speed Limitation (1) Operation in SLO with recirculation pump speed limited to less than or equal to 90% of rated pump speed does not_ increase the probability or consequences of any accident previously evaluated.

The reef.rculation pump speed will be limited to 90% of rated during SLO. The safety analysis assumed 100% pump speed in SLO. Vibration testa have been conducted on BWRs in SLO which demonstrate that all instrumented vessel internal component v4brations are within the allowable criteria. '

Heaults of these analyses and. testo show that under al) SLO

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,: operating conditions the vibration level is acceptable and bounded by previously submitted full power analyses; therefore, operation in SLO with recirculation pump speed limited to less than or equal to 90% of rated pump speed will not increase the probability or consequences of an accident previously analyzed.

(2) Operation in SLO with recirculation pump speed limited to less than or equal to 90% of_ rated pump speed does not create the-possibility of a new or different kind of accident from any accident previously evaluated.

Recirculation pump speed is not the initiating event of any accident so this change does not create the possibility of a new or different kind of accident than previously evaluated.

(3) Operation in SLO with recirculation pump speed limited to less than or equal to 90% of rated pump speed does not involve a significant reduction in a margin of safety.

Ilesults of the aforementioned analyses and testa show that SLO at loot rated pump speed is bounded by previously suliaitted full power analyses. Therefore, conservatively limiting pump speed to less than or equal to 90% of rated pump speed does not involve a significant reduction in the margin of safety.

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1 P. Stability Requirements )

1 (1) Revision of the stability monitoring requirements for operation in SLO does not increase the probability or consequences of any accident previously evaluated.

I i

These revisions regarding stability monitoring requirements .

are an addition to the current stability provisions to implement the NRC approved stability criteria (CE Co. SIL-380, Rovisicn 1) for SLO as set forth by Generic Letter 86-02, dated January 23, 1986 and Generic Letter 86-09 dated March 31, 1986. Thermal-hydraulic stability durina SLO was generically evaluated in the General Electric report NEDE-24011, Rev. 6, Amendment 8, "Thermal Hydraulic Stability Amendment to GESTAR II", dated April 24, 1985 and found to satisfy the requirements of 10CPR50, Appendix A, General Design Criterion 12. Stability monitoring provisions decrease the probability of fuel damage by avoiding limit cycle neutron flux oscillations. Consequently, these changes will not increase the probability or consequences of an accident previously analyzed. t i

< (2) Revision of the stability monitoring requirements for  ;

operation in SLO does not create the possibility of a new or different kind of accident from any accident ,

previously evaluated.

I i

I Since.these changes only-add additional stability monitoring-requirements and operating restrictions, they do not create the possibility of a new or different kind of accident than previously evaluated.

(3) Revision of the stability monitoring requiremento__for operation in SLO does_no_t involve _a significant reduction in a margin of safety.

Since these changes only add additional stability monitoring requirements'and operating restrictions to ensure that limit cycle neutron flux oscillations are avoided, they do not involve a significant reduction in the margin of safety.

G. Differential Temperature Requirements (1) The addition of recirculation loop differential temperature limits for operation in SLO does not increase the probability or consequences of any accident previously evaluated.

These revisions for surveillance of recirculation loop differential temperature are an addition to the current differential temperature requirements of Technical Specification 3.4.1.4 for idle recirculation loop startup.

The purpose of the additional surveillance on differential temperaturen below 30% thermal power or S0% rated

_- recirculation loop flow is to. mitigate undue thermal stress on vessel nozzles, recirculation pump and vessel bottom head during extended SLO. With thermal power and recirculation loop flow greater than the action levels, cold water will be adequately swept from the vessel bottom head, thus preventing stratification. Since these revisions act to decrease the possibility of undue thermal stress, the changes will not increase the probability or consequences of an accident previously analyzed.

(2) The addition of recirculation loop differential temperature limits for operation in SLO does not create the possibility of a new or different kind of accident from any accident previously evaluated.

Since the changes only add additional differential temperature monitoring requirements and operating restrictions, they do not create the possibility of a new or different kind of accident than previously evaluated.

(3) The addition of recirculation loop differential temperature limits for operation in_ SLO _does not involve a significant reduction in a margin of safety.

Since these changes simply apply the differential temperature requirementa presently existent for idle recirculation loop startup to extended SLO, they do not involve a significant reduction in the margin of safety.

o' o' II . Manual Flow Control (1). Restriction of the recirculation flow control system to the manual mode during SLO does not increase the probability or consequences of any accident previously evaluated.

To prevent potential control oscillation from occurring in the recirculation flow control system, the operation mode of the recirculation flow control system will be restricted to operation in the manual control mode for SLO. Recirculation drive flow can be significantly noialer during SLO than during normal operation, resulting in a noisier signal to the scoop tube positioner. In the manual mode, the positioner flow demand signal will be constant between operator induced demand changea. Restricting operation of the recirculation flow control system to the manual modo during SLO will not increase the probability or consequences of an accident previously analyzed since this is a normal mode of operation.

(2) Rentriction of the recirculation flow control system to the manual modo during SLO does not create the poonibility of a new or different kind of accident from any accident previously evaluated.

Operation of the recirculation flow control nyctem in the manual mode in not the initiating event of any accident and requiren no changco in the current mode of opuration;

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1 therefore, this requirement does not create the possibility of a new or different kind of accident than previously evaluated.

(3) Restriction of the recirculation flow control system to the manual mode during SLO does not involve a significant reduction in a margin of safety.

Since operation of the recirculation flow control system in the manual mode will prevent potential control oscillations from occurring in the system, this change does not involve a [

significant reduction in the margin of safety.

i I. Jet Pump Surveillance  !

(1) Revlulon of the jet pumps surveillance requirements to account for SLO does not increase the probability or consequences of any accident previously evaluated.

The changes to the jet pump surveillance requirements merely provide clarification to specifically address SLO and two-loop operation. Therefore, the changes will not increase the probability or consequences of an accident previously analyzed.

(2) Hevision of the jet pump surveillance requirements to account for SLO does not create the possibility of a new or different kind of accident from any accident previously evaluated.

't:

These changes to the jet pump surveillance requirements are not the initiating event of any accident and require no changes in the current mode of operation; therefore, they do not create the possibility of a new or different kind of accident than previously evaluated.

(3) Revision of the jet pump surveillance requirements to

! account for SLO does not involve a significant reduction in a margin of safety.

Since these changes result in surveillance requirements of the operating jet pumps in SLO identical to those existent for two-loop operation, they do not involve a significant reduction in the margin of safety.

J. Administrative Changes (1) The proposed administrative changes do not increase the probability or consequences of any accident previously evaluated.

The proposed change to the note on page J/4 2-7 deletes the reference to "power ascension" when adjusting APRM setpoints by adjusting the APRM gain when the MFLPD is greater than the

~33-

PRTP . . The proposed change to pages 3/4 2-10 and 3/4 2-10a simply provides clarification that the current MCPR operating limits are applicable to both two recirculation loop and single recirculation loop operation. The proposed change to the ACTION of Technical Specification 3.4.1.3 on page 3/4 4-5 will require the shutdown of one of the two recirculation loops when recirculation flow mismatch exceeds the limit rather than declaring the loop or slower speed not in operation. These two proposed changes merely provide clarification of the existent specifications; therefore, these changes will not increase the probability or consequences of an accident previously analyzed.

(2) The proposed administrative changes do not create the 2

pcssibility of a new or different kind of accident from any accident previously evaluated.

1 These changes are not the initiating event of any accident and require no changes in the current mode of operation; therefore, they do not create the possibility of a new or i

different kind of accident than previously evaluated.

(3) The pgoposed adminiotrative changes do not involve a significant reduction in a margin of safety.

Since these changes only serve to better define the requirements of the appropriate 1,COs, they do not involve a uignificant reduction in the margin of safety.

i

Environmental Consideration An environmental impact assessment is not required for the changen requested by this Application because the requested changes conform to the criteria for "action eligible for categorical exclusion" as specified in 10 CPR Sl.22(c)(9). The changes involve no significant hazards consideration as demonstrated in the preceding section. The changes involve no significant change in the types or significant increase in the amounta of any effluento that may be released offsite, and there la no significant increase in individual or cumulative occupational radiation exposure.

Conclusion The proposed technical specification changes will allow operation of Limerick Generating Station Unit I at reduced power with only one of two reactor recirculation loops in service and will provide increased operational flexibility. All the applicable design basin accidents and abnormal operational transiento presented in the LGS FSAR have been reviewed to determine the impact of the requented changen. Operation of the unit with one recirculation loop in service and within the technical specification limitations proposed herein will not reault in any decrease in the level of safe operation of the unit.

The Plant Operations Hoview Committee and the Nuclear Heview Iloard have reviewed the proposed changes to the Technical 1

Specificationa and have concluded that they do not involve an unreviewed safety question or a significant hazards consideration and will not endanger the health and safety of the public.

Respectfully submitted, PilILADEI. PHI A ELECTRIC COMPANY

& $$'hs Opice Presida!nt

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y COMMONWEALTil OF PENNSYLVANI A  :

ss.

COUNTY OP.PtilLADELPilIA  :

J. W. Gallagher, being first duly sworn, deposes and says:

That he is Vice President of Philadelphia Electric Company, the Applicant herein; that he has read the' foregoing Application for Amendment of Facility Operating License and knows the contents thereof; and that'the statements and matters set forth 1 therein are true and correct to the best of his knowledge, information and belief.

._ N V O Vice President Suhneribed and sworn to before me this 31'^ day of oct, 1988.

Lddd f blibS .

Notary Public P.OT ARtAL SEAL JVCETH Y FRANvuN Newy Pubke C4 d Phe'40ticha Ptva Co#N My Comrmst.oo Esedes . Air 28.199f a

GENERAL ELECTRIC C0MPANY AFFIDAVIT I, Rudolph Villa, being duly sworn, depose and state as follows:

1. I am Manager, Consulting Services, General Electric Company, and have been delegated the function of reviewing the information described in paragraph 2 which is sought to be withheld and have been authorized to apply for its withholding.

2. The information sought to be withheld is contained in the GE prop-rietary report NEDC-31300-P, "Single Loop Operation Analysis for Limerick Generating Station Unit 1", October 1988. This report justifies operation of Limerick Unit I at reduced power with only a single recirculation pump in operation. It reviews accidents and abnormal operational transients presented in the Limerick FSAR, Sections 6.2, 6.3 and the main text of Chapter 15, with only a single recirculation pump in operation.

"A trade secret may consist of any formula, pattern, device or compilation of information which is used in one's business and which gives him an opportunity to obtain an advantage over competiter:, who do not know or use it... A substantial element of secrecy must exist, so that, except by the use of improper means, there would be difficulty in acquiring information...

Some factors to be considered in determining whether given information is one's trade secret are (1) the extent to which the information is known outside of his business; (2) the extent to which it is known by employees and others involved in his business; (3) the extent of measures taken by him to guard the secrecy of the information; (4) the value of the information to him and to his competitors; (5) the amount of effort or money expanded by him developing the information; (6) the ease or difficulty with which the information cauld be properly acquired or duplicated by others."

3. Some examples of categories of information which fit into the definition of Proprietary Informatica are:

a. Information that discloses a process, method or apparatus where prevention of its use by General Electric's competitors without license from General Electric c]nstitutes a competitive economic advantage over other companies;

b. Inforaation consisting of supporting data and analyses, including test data, relative to a process, method or apparatus, the application of which provide a competitiva economic advantage, e.g,. by optimization or improved marketability;

GENERAL ELECTRIC C0NPANY

c. Information which if used by a competitor, would reduce his expenditures of rescurces or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality or licensing of a similar product;

d. Information which reveals cost or price information produc-tion capacities, budget levels or comnercial strategies of General Electric, its customers or suppliers;

-e. Information which reveals aspects of past, present or future General Electric customer-funded development plans and programs of potential commercial value to General Electric:

f. Information which discloses patentable subject matter for which it may be desirable to obtain patent protection;

g. Information which General Electric must treat as proprietary according to agreements with other parties.

4. Initial approval of proprietary treatment of a document is typi-cally made by the Subsection Manager of the originating component, the person who is most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge.

Access to such documents within the Company is limited on a "need to know" basis and such documents are clearly identified as proprietary.

5. The procedure for approval of external release of such a document typically requires review by the Subsection Manager, Project Manager, Principal Scientist or other equivalent authority, by the Subsection Manager of the cognizant Marketing function (or dele-gate) and by the Legal Operation for technical contr.nt, competi-tively effect and determination of the accuracy of the proprietary designation in accordance with the standards enumerated above.

Disclosures outside General Electric are generally limited to regulatory bodies, customers and potential customers and their agents, suppliers and licensees then only with appropriate protec-tion by applicable regulatory provisions or proprietary agreements.

6. The document mentioned in paragraph 2 above has been evaluated in accordance with the above criteria and procedures and has been

, found to contain information which is proprietary and whi:h is customarily held in confidence by General Electric.

7. The information to the best of my knowledge and belief has consis-tently been held in confidence by the General Electric Company, no public disclosure has been made, and it is not available in public sources. All disclosures to third parties have been made pursuant to regulatory prov!sions of proprietary agreements which provide for maintenance of the information in confidence.

8. Public disclosure of the information sought to be withheld is likely to cause substantial harm to the competitive position of the i Gr.neral Electric Company and deprive or reduce the availability of paofit making opportunities because it would provide other parties, 11cluding competitors, with valuable information.

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-__y _n.,_m__,,____,,,,,._.-,__.___._-____m __ ___ .,~g . .- , . . _ . _ ,

GENERA'L ELECTRIC COMPANY STATE OF CALIFORNIA ss:

COUNTY OF SANTA CLARA Rudolph Villa, being duly sown, deposes and says: ,

That he has read the foregoing affidavit and the matters stated therein are true and correct to the best of his knowledge, information, and belief.

Executed at San Jose, California, this / ay of @ 19 .

f ,

Rudolph' Villa General Electric Company Subscribed and sworn before me this f b ay of 8 [ O 19,78.

blm W$M Notary Putdic, State of California

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OFFICIAL SEAL NOTA PV8LIC L 704 NIA I

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