B15067, Application for Amend to License NPF-49,modifying SR 4.8.1.1.2.g.3 That Will Permit DG Full Load Rejection Tests to Be Performed at Realistic Plant Conditions Using Power Factor to Envelope Calculated Power Factor

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Application for Amend to License NPF-49,modifying SR 4.8.1.1.2.g.3 That Will Permit DG Full Load Rejection Tests to Be Performed at Realistic Plant Conditions Using Power Factor to Envelope Calculated Power Factor
ML20079B013
Person / Time
Site: Millstone Dominion icon.png
Issue date: 12/23/1994
From: Debarba E
NORTHEAST NUCLEAR ENERGY CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20079B015 List:
References
B15067, NUDOCS 9501040242
Download: ML20079B013 (9)
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Text

___-________________-__-_ - _._ -_______- __--_____ _____-_____________-___ _ ____-_ _ - - - _

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, 1 7 sciaen street, seriin, cr 06037

'"3 Northeast.

, Utilities System Nonhcast Unhues Smke Company .

P.O. Box 270 Ilartford, CT 06141-0270 (203) 665-5000 December 23, 1994 l

Docket No. 50-423 B15067 Ret 10CFR50.90 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Millstone Nuclear Power Station, Unit No. 3  !

i Proposed Revision to Technical Specifications Diesel Generator Full-Load Reiection Test and Fuel Oil System Pressure Test Introduction Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Operating License, NPF-49, by incorporating the changes identified in Attachments 1 and 2 into the Millstone Unit No. 3 Technical Specifications. NNECO is proposing to modify Surveillance Requirement 4.8.1.1.2.g.3 of the Millstone Unit No. 3 Technical Specifications and to delete Surveillance Requirement 4.8.1.1.2.1.2 from the Millstone Unit No. 3 Technical Specifications. The proposed change to modify Surveillance Requirement 4.8.1.1.2.g.3 will permit the diesel generator (DG) full load rejection tests to be performed at realistic plant conditions using a power factor that will envelope the calculated power factor during the worst kW loading conditions.

NNECO is proposing to delete the 10-year surveillance requirement to perform a 110% pressure test of the DG fuel oil system, because it is redundant to the requirements of Surveillance Requirement 4.0.5 and the fuel oil system cannot be tested to the requirements of Surveillance Requirement 4.8.1.1.2.1.2.

Descrintion of the Fronosed chamees NNECO is proposing to modify Surveillance Requirement 4.8.1.1.2.g.3 by increasing the acceptance criterion for the peak transient generator voltage from 4784 volts to 5000 volts. The proposal maintains the acceptance criterion for the steady-state generator voltage following the load rejection at 4784 volts. The proposed revision to Surveillance Requirement 4.8.1.1.2.g.3 would permit the DG full load rejection tests to be performed at realistic plant conditions using a power factor that will envelope the calculated power factor during the worst kW loading conditions. The peak transient voltage of 5000 volts is within the design limits of the DGs.

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. i U.S. Nuclear Regulatory Commission B15067/Page 2 ,

December 23, 1994 l l

Additionally, NNECO is proposing to delete Surveillance Requirement '

4.8.1.1.2.1.2, because it is redundant to the requirements of Surveillance Requirement 4.0.5 and the fuel oil system cannot be tested in accordance with Surveillance Requirement 4.8.1.1.2.1.2 i because the DG fuel oil tanks are vented to the atmosphere and this vent path cannot be isolated.

Attachments 1 and 2 provide the marked-up and retyped pages of the Millstone Unit No. 3 Technical Specifications, respectively. They reflect the currently issued version of the pages. They do not  ;

reflect the proposed changes submitted on December 9, 1994.m ,

Therefore, NNECO suggests that the NRC Staff check with NNECO prior l to issuing these pages to ensure continuity with license amendments ,

issued after the date of this submittal.

safety Assessment D111 Load Reiection l Surveillance Requirement 4.8.1.1.2.g.3 of the Millstone Unit No. 3 i Technical Specifications requires the verification of the  !

capability of the DGs to reject a load of 4986 kW without tripping ,

or exceeding the specified voltage limits. It ensures that the DG  !

properly responds to the simulated test conditions. The purpose of this surveillance is to simulate the loss of the total connected load that the DGs experience following a full load rejection and to i verify that the DGs do not trip upon loss of the load. The acceptance criterion is provided to ensure that the DGs would be capable of reconnecting to the bus if the trip initiator can be corrected or isolated and to protect the DGs.

In the past, the full load rejection tests on the Millstone Unit No. 3 DGs were conducted with a unity power factor. This is

. consistent with the existing surveillance requirement. In order to ensure that the DGs are tested under load conditions that are as close as possible to design basis conditions (i.e., 3 to 3.2  :

MVARs), NNECO intends to perform the subject surveillance with a power factor between 0.84 and 0.86. This power factor is representative of the actual design basis inductive loading that a DG would experience. However, this lower power factor will result in a higher transient voltage during full load rejection. Thus, NNECO is proposing to revise the acceptance criterion regarding transient voltage limits.

(1) J. F. Opeka letter to the U.S. Nuclear Regulatory Commission,

" Millstone Nuclear Power Station, Unit No. 3, Proposed Revision to Technical Specifications, Diesel Generator Surveillance Requirements," dated December 9, 1994.

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U.S. Nuclear Regulatory Commission B15067/Page 3  ;

December 23, 1994  ;

i Currently, the voltage limit is 4784 volts during and following the  !

load rejection. NNECO's proposal changes the acceptance criterion to: "The generator voltage shall not exceed 5000 volts during and 4784 volts following the load rejection." These values are within  ;

the design limits for the DGs. Also, the peak transient. voltage of i 5000 volta has a very short duration. This proposed change is l consistent with the Improved Westinghouse owner's Group Standard ,

Technical Specifications (i.e., NUREG-1431). Incorporating the -

proposed voltage limits would permit the DG full load rejection >

tests to be performed with a power factor between 0.84 and 0.86. j The proposal will not affect the capability of the DGs to perform i their intended safety function, reduce the availability of the DGs, ,

or change the manner in which the plant or plant personnel respond  !

to a loss of offsite power. The proposed change to the acceptance l criterion is within the design limits of the DGs, and it will I continue to ensure that the DGs are not damaged during the performance of a full load rejection test. Therefore, the proposed change will not impact public health and safety.

Pressure Test of the DG Fuel Oil System l Regulatory Guide 1.137, " Fuel-Oil Systems for Standby Diesel l Generator," adopts Section 7.3 of ANSI N195-1976, " Fuel Oil Systems j for Standby Diesel-Generators," which specifies testing in .

accordance with ASME Section XI, " Rules for Inservice Inspection of Nuclear Power Plant Components." ASME Section XI, Article IWD-5000, requires testing of components at 1.10 times the system design - pressure, for systems with design temperatures less than 200* F, or, in the case of atmospheric storage tanks, the hydrostatic head is developed with the tank filled to design capacity.

The testing methodology specified by Surveillance Requirement 4.8.1.1.2.1.2 is not practical for the current design of the DG fuel oil system. The DG fuel oil tanks are vented to atmosphere without an existing ability to isolate and pressurize during the performance of the specified pressure test. Therefore, due to the system incompatibility with the requirements to perform the pressure test at 110 percent of system pressure, Millstone Unit No. 3 is requesting the proposed change. Additionally, Surveillance Requirement 4.8.1.1.2.1.2 is redundant to Surveillance Requirement 4.0.5.

The DG fuel oil system is an ASME Code Class 3 system. Testing of l ASME Code Class 1, 2, and 3 systems is required to be performed in j accordance with ASME Section XI by Surveillance Requirement 4.0.5.

Therefore, deleting Surveillance Requirement 4.8.1.1.2.1.2 will have no impact on plant safety or system reliability.

I

t U.S. Nuc' lear Regulatory Comalssion  !

B15067/Page 4 l

December 23, 1994 ,

i Millstone Unit No. 3 will include the DG fuel oil system pressure .

test as an augmented inspection within the Inservice Inspection Program. Inspections will be performed in compliance with the requirement of the 1983 Edition of ASME Section XI, Table IWD-2500-1, " Test and Examination Categories." Testing (i.e. , a system hydrostatic test) in accordance with ASME-Section XI will provide  !

equivalent assurance of tank and piping integrity.  !

This proposed change is similar to an amendment issued by the NRC Staff on March 19, 1993, regarding the Wolf Creek Generating Station.#

Biqrnificant Essards consideration l t

NNECO has reviewed the proposed changes in accordance with 10CFR50.92 and concluded that the changes do not involve a significant hazards consideration (SHC). The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised. The proposed changes do not involve a SHC because the i

changes would not: '

1. Involve a significant increase in the probability or consequences of an accident previously analyzed.

DG Full-Load Reiection Test l

NNECO is proposing to modify Surveillance Requirement  !

4.8.1.1.2.g.3 of the Millstone Unit No. 3 Technical  ;

Specifications by changina the acceptable transient voltage to [

5000 volts from 4784 volts. This change will permit the DG ,

full load rejection tests to be performed at realistic plant  ;

conditions using a power factor that will envelope the ,

calculated power factor during the worst kW loading conditions. The transient voltage of 5000 volts is within the i normal design limits of the DGs.

P The proposed change does not alter the intent of the surveillance, does not involve any physical changes to the '

plant, does not alter the way any structure, system, or component functions, and does not modify the annner in which ,

the plant is operated. As such, the proposed change to .

Surveillance Requirement 4.8.1.1.2.g.3 will not degrade the ,

capability of the DGs to perform their intended safety ,

function, and will not reduce the availability of the DGs. l i

(2) W. D. Reckley letter to B. D. Withers, " Wolf Creek Generating [

Station - Amendment No. 60 to Facility Operating License No.

NPF-43 (TAC No. M85269)," dated March 19, 1993.

U.S. Nuc' lear Regulatory Commission B15067/Page 5 December 23, 1994 Actually, the proposed change will increase the effectiveness of the full load rejection tests, because the DGs will be tested in a configuration that is closer to the design basis conditions.

Pressure Test of the DG Fuel Oil System The DG fuel oil system is classified as an ASME Code Class 3 system in accordance with the guidance of Regulatory Guide 1.16, " Quality Group Classification and Standards for Water ,

Steam , and Radioactive-waste Components of Nuclear Power Plants." Surveillance Requirement 4.0.5 requires the testing of ASME Class 1, 2, and 3 components in accordance with Section XI of the ASME Code. Surveillance Requirement 4.8.1.1.2.1.2 is redundant to the ASME Section XI pressure test requirements of Surveillance Requirement 4.0.5.

Additionally, the DG fuel oil tank cannot be tested in the configuration required by Surveillance Requirement 4.8.1.1.2.1.2, because the tanks are vented to the atmosphere and the vent cannot be isolated. Therefore, NNECO is proposing to delete Surveillance Requirement 4.8.1.1.2.1.2.

The proposed change does not modify the manner in which the DGs respond to an accident. Also, the proposed change does not reduce the reliability of the DGs. l Conclusion Based on the above, the proposed changes to Surveillance I Requirements 4.8.1.1.?.g.3 and 4.8.1.1.2.1.2 of the Millstone  !

Unit No. 3 Technical Specifications do not involve a significant increase in the probability or consequences of an accident previously analyzed.

2. Create the possibility of a new or different kind of accident from any previously analyzed.

DG Full-Load Reiection Test The DGs are required to operate in response to a loss of offsite power. Their failure cannot initiate an accident.

Additionally, the proposed change to Surveillance Requirement 4.8.1.1.2.g.3 does not affect the operation or response of any plant structure, system, or component, and it does not introduce any new failure mechanisms.

+ . . j U.S. Nuclear Regulatory Commission l

~B15067/Page 6  !

December 23, 1994 l l

t Pressure Test of the DG Fuel Oil System. i i

The proposed change to surveillance Requirment. 4.8.1.1.2.1.2 does not affect the design or function of the DG fuel oil system. Failure of the DG fuel oil system would not initiate  ;

an accidant. j i

Conclusion Based on the above, the proposed changes to Surveillance Requirements 4.8.1.1.2.g.3 and 4.8.1.1.2.1.2 of the Millstone '

Unit No. 3 Technical Specifications will not create the possibility of a new or different kind of accident from any  ;

previously evaluated. j

3. Involve a significant reduction in the margin of safety. j i

DG Full-Load Reiection Test i NNECO is propcsing to modify Surveillance Requirement l 4.8.1.1.2.g.3 cf the Millstone Unit No. 3 Technical _;

specifications by changing the acceptable transient voltage to  !

5000 volts from 4784 volts. The intent of the proposal is to ,

permit the DG full load rejection tests to be conducted at l conditions which simulate design basis conditions. l The proposed change does not alter the intent of the I surveillance, does not involve _ any physical changes to the ,

plant, does not alter the way any structure, system, or .

component functions, and does not modify the manner in which  !

the plant is operated. As such, the proposed change to surveillance Requirement 4.8.1.1.2.g.3 will not degrade the ability of the DGs to perform their intended safety function, and will not reduce the availability of the DGs.  :

I The bases of Technical Specification 3/4.8, " Electrical Power systems," state that the operability of the AC and DC power i systems and associated distribution systems ensure that  !

sufficient power will be available to supply the safety related equipment required for safe shutdown and for the mitigation of transients. The proposed change to the surveillance requirement will increase the effectiveness of the full load rejection tests. This will ensure the operability of the DGs. Operable DGs ensure that the assumptions for the bases of the Millstone Unit No. 3 Technical specifications are not affected.

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l U.S. Nuclear Regulatory Commission j B15067/Page 7 '

December 23, 1994 .

Pressure Test of the DG Fuel Oil System NNECO is proposing to delete Surveillance Requirement 4.8.1.1.2.1.2 from the Millstone Unit No. 3 Technical Specifications. This surveillance requirement is redundant to the requirements of Surveillance Requirement 4.0.5 which invokes ASME Section XI. Additionally, the fuel oil system cannot be tested to -the requirements of Surveillance Requirement 4.8.1.1.2.1.2 because the DG fuel oil tanks are vented to the atmosphere and this vent path cannot be isolated.

l Millstone Unit No. 3 will include the DG fuel oil system I pressure test as an augmented inspection within the Inservice Inspection program. Inspections will be performed in compliance with the requirement of the 1983 Edition of'ASME Section XI, Table IWD-2500-1, " Test and Examination Categories." Testing (i.e., a system hydrostatic test) in accordance with ASME Section XI will provide equivalent assurance of tank and piping integrity.

Conclusion Based on the above, the proposed changes to Surveillance Requirements 4 . 8 .1.1. 2 . g . 3 and 4 . 8 .1.1. 2 .1. 2 of the Millstone Unit No. 3 Technical Specifications do not involve a significant reduction in the margin of safety.

The commission has provided guidance concerning the application of the standards of 10CFR50.92 by providing certain examples (51 FR 7751, March 6, 1986) of amendments that are not considered likely to involve an SHC. While the proposed changes to Surveillance Requirements 4.8.1.1.2.g.3 and 4.8.1.1.2.i.2 are not enveloped by any of the examples, they do not involve an SHC. The proposed changes do not alter the design or function of the DGs, and do not reduce the availability of the DGs.

Environmental Considerations NNECO has reviewed the proposed license amendment against the criteria of 10CFR51.22 for environmental considerations. The proposed changes do not increase the types and amounts of offluents that may be released offsite, nor signifi'.:antly increase individual or cumulative occupational radiation exposures. Based on the foregoing, NNECO concludes that the proposed changes meet the criteria delineated in 10CFR51.22(c)(9) for a categorical exclusion from the requirements for an environmental impact statement.

Y U.S. Nuclear Regulatory Commission B15067/Page 8 December 23, 1994 I

Muclear Review Board The Millstone Unit No. 3 NRB has reviewed and concurred with the above determinations.

State of Connecticut In accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment to ensure their awareness of this request.

Schedule Reauired for MRC Ancroval The tests required by Survaillance Reydirements 4.8.1.1.2.g.3 and 4.8.1.1.2.1.2 are scheduled to be performed during the upcoming refueling outage. Therefore, to support the performance of these tests, NNECO is requesting that the NRC complete their review prior to April 1995 (the currently scheduled start date for the refueling outage).

If the NRC Staff should have any questions or comments regarding ,

this submittal, please contact Mr. R. G. Joshi at (203) 440-2080. j We will promptly provide any additional information the NRC Staff may need to respond to this request. We appreciate your efforts in i support of this request. l Very truly yours,  ;

NORTHEAST NUCLEAR ENERGY COMPANY FOR: J. F. Opeka  ;

Executive Vice President i BY: .-

E. A. DeBarba o

bob Vice President cc: See Page 9

O i

U.S. Nuclear Regulatory Commission '

B15067/Page 9 December 23, 1994 B

cc: T. T._ Martin, Region I Administrator i V. L. Rooney, NRC Project Manager, Millstone Unit No. 3 i P. D. Swetland, Senior Resident Inspector, Millstone Unit  ;

Nos. 1, 2, and 3 Mr. Kevin T.A. McCarthy, Director Monitoring and Radiation Division l Department of Environmental Protection '

79 Elm Street P.O. Box 5066 Hartford, CT 06102-5066 Subscribed and sworn to before me this M 3 day o Dr>o pw A t U , 1994

$ Okht l 0 Oh000ALJ Data Commission Expires: // [l /// ~ - f[ l g  :

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