ML20206R810

Application for Amend to License DPR-35,requesting NRC Review & Approval of Change to TS Section 3/4.5.C, HPCI, Sys,Section 3/4.5.D, RCIC Sys & Bases Associated with Sections

ML20206R810
Person / Time
Site:	Pilgrim
Issue date:	05/11/1999
From:	Ted Sullivan BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20206R813	List: ML20206R810 ML20206R816
References
LTR.2.99.041, NUDOCS 9905200203
Download: ML20206R810 (9)

Text

,___. . .

10CFR50.90 I

9 Boston Edison A BEC ENERGY COMPANY a

T.A. Sumvan May 11,1999 Vice President Nuclear BECo Ltr. 2.99.041 and Station Director U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Docket No. 50-293 License No. DPR-35 REQUEST FOR TECHNICAL SPECIFICATION CHANGE CONCERNING HPCI AND RCIC SURVEILLANCE TESTING PURPOSE Boston Edison Company (Pilgrim Nuclear Power Station) requests NRC review and approval for a change to Pilgrim Technical Specification section 3/4.5.C, "High Pressure Coolant injection (HPCI)"

system; section 3/4.5.D, " Reactor Core isolation Cooling (RCIC)" system; and the Bases associated with these sections. Pilgrim proposes to increase the upper limit of the reactor pressure range for each system and to change the 150 psig pump surveillance test to specifically allow the test to be conducted at a lower flow rate with the restricting orifice installed in the test line.

BACKGROUND //

j A design review determined the applicable reactor pressure range of the HPCI and RCIC systems is 150 psig up to the safety / relief valve setpoint of 1126 psig. The current Technical Specifications require both systems to provide the required flow rate over a range of reactor pressures from 150 psig /hn to 1000 psig. Design requirements from General Electric and original startup testing for each system /

indicated each system should provide the required flow rate for a system head corresponding to the setpoint of the safety / relief valve with the lowest setpoint. The current Technical Specification governing safety / relief valve setpoints specifies each of the four relief valves have a setpoint no greater than 1115 11 psig. Therefore, an increase to the upper pressure of the HPCI and RCIC operating range from 1000 psig to 1126 psig is proposed.

Each HPCI and RCIC system test line includes a restricting orifice that partially simulates the resistance the pump is required to overcome while delivering the required flow rates to the reactor vessel. Neither system is capable of achieving the flow rate required by the Technical Specifications during the 150 psig test when the orifice is installed. Before 1991, the restricting orifice in both systems was removed to conduct the 150 psig tests and the required ficw rate was demonstrated.

Engineering studies were performed to develop alternate acceptance criteria based on pump affinity laws to be used for the 150 psig test with the orifice installed. The alternate acceptance criteria consisted of a specified minimum flow rate that is lower than the existing Technical Specification 9905200203 990511 PDR ADOCK 05000293

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requir:m:nt, turbins spe:d limit, cnd minimum pump h::d. Alt rnata pump t:st acc:ptanca crit:ria such cs this is bis:d on bisic engineering principl:s and provid::s a t:chnicilly acc:pt:bla m:thod to verify HPCI and RCIC performance at 150 psig; however, verbatim compliance with the existing Technical Specification wcrding is not achieved when using this method. Hence, Pilgrim proposes a

. Technical Specification change to specifically allow the 150 psig test of the HPCI and RCIC systems by equivalent testing with the restricting orifices installed.

Please contact P.M. Kahler at (508) 830-7939 if you should require further information on this issue.

1

- 7d  ;

T. A. Sullivan l Commonwealth of Massachusetts)

County of Plymouth )

Then personally appeared before me, T. A. Sullivan, who being duly sworn, did state that he is Vice President Nuclear, Station Director of Boston Edison Company and that he is duly authorized to execute and file the submittal contained herein in the name and on behalf of Boston Edison Company and that the statements are true to the best of his knowledge . belief.

My commission expires:bmMA 0 A MA- '

' DATE / NOTARY PLIBLIC Attachments:

1) Narrative on Proposed Change and "No Significant Hazards Consideration"

2) Proposed Changed PilgrimTechnical Specification Pages 3/4.5-7; 3/4.5-8; B3/4.5-18; B3/4.5-19; B3/4.5-20

3) Marked-up Current Pilgrim Pages 3/4.5-7; 3/4.5-8; B3/4.5-18; B3/4.5-19; B3/4.5-20 l

l TAS/PMK/cis l 2.99.041 ,

l cc: Mr. Alan B. Wang, Project Manager Mr. Robert M. Hallisey, Director Project Directorate 1-3 Radiation Control Program Office of Nuclear Reactor Regulation Commonwealth of Massachusetts Mail Stop: OWFN 8F2 Exec Offices of Health & Human Services 1 White Flint North Dept. of Public Health 11555 Rockville Pike 174 Portland Street Rockville,MD 20852 Boston, MA 02114 U.S. Nuclear Regulatory Commission Mr. Quirinom lannazzo, Acting Director Region l Mass. Emergency Management Agency l 475 Allendale Road 400 Worcester Road King of Prussia, PA 19406 P.O. Box 1496 Framingham, MA 01701-0313 Senior Resident inspector i Pilgrim Nuclear Power Station

ATTACHMENT 1 - BECo LETTER 2 99.041 DESCRIPTION OF PROPOSED CHANGE j

. 1 Hiah Pressure Coolant inloction System Pilgrim Nuclear Power Station (Pilgrim) Technical Specification section 3/4.5.C.1.b,"High Pressure injection System, Pump Operability" currently states:

When tested as specifiedin 3.13, verify that the HPCIpump delivers at least 4250 GPM for a system head corresponding to a reactor pressure of 1000 psig.

This proposed change alters this requirement to read:

When tested as specified in 3.13, verify that the HPCIpump delivers at least 4250 GPM 1 for a system head corresponding to a reactor pressure of 1126 psig. )

Pilgrim Nuclear Power Station (Pilgrim) Technical Specification section 3/4.5.C.1.d, "High Pressure injection System, Flow Rate at 150 psig" currently states:

Once/ operating cycle, verify that the HPCIpump c'elivers at least 4250 gpm for a system head corresponding to a reactorpressure at 150 psig.

This proposed change alters this requirement to read:

Oncdoperating cycle, verify that the HPCIpump delivers at least 4250 gpm for a system head corresponding to a reactorpressure at 150 psig. This surveillance may be satisfled by an equivalent test.

Pilgrim Nuclear Power Station (Pilgrim) Technical Specification section 3/4.5.C.1,"High Pressure injection System" currently states:

The HPCIpump shall deliver at least 4250 GPM for a system head corresponding to a reactorpressure of 1000 to 150 psig.

This proposed change alters this requirement to read:

The HPCIpump shall deliver at least 4250 GPM for a system head corresponding to a reactor pressure range of 1126 to 150 psig.

This proposed change modifies the high pressure coolant injection (HPCI) " Bases" by changing the second paragraph in the section titled " Background" information in 3/4.5.C:

The capacity of the system is selected to provide this required core cooling. The HPCI pump is designed to pump 4250 gpm at reactorpressures between 1126 and 150 psig.

This proposed change modifies the high pressure coolant injection (HPCI) " Bases" by adding to the section titled "Surveillances" the following narrative describing the equivalent test which is being added to 3/4.5.C.1.d:

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The HPCIpump txt corte:ponding 12 0 reactor pressure cf 150 psig may be perfirmed

, with the restricting orifice removed from or in:t:lled in the return line ta the condensate storage tanks. If the restricting orifice is removed, the HPCI pump shall 1 deliver 4250 GPM. If the restricting orlHoe is Installed, an equivalent test for the HPCI

. pump is permissible. The acceptance criteria for the equivalent test is derived to I demonstrate equal or greater level of pump performance in terms of brake horsepower but at a higher pump head and lower flow rate.

1 Reactor Core isolation Coolina System l

Pilgrim Nuclear Power Station (Pilgrim) Technical Specification section 3/4.5.D.1," Reactor Core Isolation Cooling (RCIC) System" currently states-1 "HPCI system testing shall be as follows:"

This proposed change alters this requirement to read:

"RCIC system testing shall be as follows:"

l Pilgrim Nuclear Power Station (Pilgrim) Technical Specification section 3/4.5.D.1.5, " Reactor Core Isolation Cooling (RCIC) System, Pump Operability" currently states:

When tested as specified in 3.13, verify that the RCIC pump delivers at least 400 GPM for a system head corresponding to a reactor pressure of 1000 psig. '

1 This proposed change alters this requirement to read: ,

l When tested as specified in 3.13, verify that the RCIC pump delivers at least 400 GPM l for a system head corresponding to a reactor pressure of 1126 psig.

Pilgrim Nuclear Power Station (Pilgrim) Technical Specification section 3/4.5.D.1.d, " Reactor Core l lsolation Cooling (RCIC) System, Flow Rate at 150 psig" currently states:

Oncafoperating cycle, verify that the RCIC pump delivers at least 400 gpm for a system head corresponding to a reactorpressure at 150 psig.

This proposed change alters this requirement to read:

Once/ operating cycle, verify that the RCIC pump delivers at least 400 gpm for a system head corresponding to a reactor pressure at 150 psig. This surveillance may be satisfiedbyan equivalent test.

Pilgrim Nuclear Power Station (Pilgrim) Technical Specification section 3/4.5.D.1, " Reactor Core Isolation Cooling (RCIC) System" currently states:

The RCIC pump shall deliver at least 400 GPM for a system head corresponding to a reactorpressure of 1000 to 150psig.

l This proposed change alters this requirement to read:

The RCIC pump shall deliver at least 400 GPM for a system head corresponding to a reactorpressure range of 1126 to 150 psig.

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l This propos:d chang 3 modifirs tha rsactor cora isolation cooling (RCIC) syst:m "B:s:s" by changing tha first pir:gr:ph in th3 section titi:d " Background" information in 3/4.5.D:

The pumping capacity of the RCIC system is sufficient to maintain the waterlevel above the

. core without any other system available to supply water to the reactor core. The RCIC system is designed to pump 400 gpm at reactorpressures between 1126 and 150 psig.

This proposed change modifies the reactor core isolation cooling (RCIC) system " Bases" by adding to I the section titled "Surveillances" the following narrative describing the equivalent test which is being added to 3/4.5.D.1.d: .

The RCIC pump test corresponding to a reactor pressure of 150 pounds psig may be performed with the restricting orifice removed from orinstalledin the return line to the condensate storage tanks. If the restricting orifice is removed, the RCIC pump shall deliver 400 GPM. If the restricting orifice is installed, an equivalent test for the RCIC pump is permissible. The acceptance criteria for the equivalent test is derived to demonstrate equal or greater level of pump performance in terms of brake horsepower but at a higher pump head and lower flow rate.

REASON FOR PROPOSED CHANGE A design review determined the applicable reactor pressure range of the HPCI and RCIC systems is 150 psig up to the safety / relief valve setpoint of 1126 psig. The current Technical Specifications require both systems to provide the required flow rate over a range of reactor pressures from 150 psig to 1000 psig. Design requirements from General Electric and original startup testing for each system indicated each system should provide the required flow rate for a system head corresponding to the setpoint of the safety / relief valve with the lowest setpoint. The current Technical Specification governing safety / relief valve setpoints (3.6.D.1.) specifies each of the four relief valves have a setpoint no greater than 1115 11 psig. Therefore, an increase to the upper pressure of the HPCI and RCIC operating range from 1000 psig to 1126 psig is proposed.

Each HPCI and RCIC system test line includes a restricting orifice that partially simulates the resistance the pump is required to overcome while delivering the required flow rate to the reactor vessel. The HPCI and RCIC orifices simulate reactor pressures of approximately 930 psig and 1100 psig, respectively. During testing, the remainder of the system resistance is introduced via a remote manual throttle valve located on the test line. Neither system is capable of achieving the flow rate required by the Technical Specifications during the 150 psig test when the orifice is installed because of high resistance. Before 1991, the restricting orifice in each system was removed to conduct the 150 psig test, and the required flow rate was demonstrated. Engineering studies were performed to develop alternate acceptance criteria based on pump affinity laws to be used for the 150 psig test with the orifice installed. The alternate acceptance criteria consisted of a specified minimum flow rate that is lower than the existing Technical Specification requirement, a turbine speed limit, and a minimum pump head. Attemate pump test acceptance criteria such as this is based on basic engineering principles and provides a technically acceptable method to verify HPCI and RCIC performance at 150 psig; however, verbatim compliance with the existing Technical Specification wording is not achieved when using this method. Hence, Pilgrim proposes a Technical Specification change to specifically allow the 150 psig test of the HPCl and RCIC systems by equivalent testing with the restricting orifices installed.

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SAFETY EVALUATION Upper limit of HPCI and RCIC System Operatina Rance Since the facility operating license No. DPR-35 for Pilgrim Nuclear Power Station was issued in 1972, the upper limit for the HPCI and RCIC operating range as specified in the Technical Specifications has been 1000 psig. This specification is nonconservative because, in 1972, the limiting safety system setting for each safety / relief valve (SRV) was 1095 psig 11 psi. Based on a recent design review, the applicable reactor pressure range for the HPCI and RCIC systems is from 150 psig up to the lowest j SRV setpoint. This requirement is derived from safety analysis that credits the performance of these systems from 150 psig up to the reactor pressure control point of the installed SRV(s) at the time the system reaches rated flow. Therefore, because the SRVs could be set as high as 1106 psi, the HPCI and RCIC system operating range upper limit of 1000 psig should have been specified at 1106 psi in the facility operating license issued in 1972. The original performance characteristics of the HPCI and RCIC systems were to provide the required flow rates over a wide range of reactor pressures (150 to 1120 psig between the pump suction and reactor vessel). These design performance characteristics )

exceeded the range established by the SRV setpoint requirements.

Amendment No. 73 (December 29, 1983) to the facility operating license revised the Technical Specifications to permit operation with increased SRV setpoints to enable an increased pressure differential between the normal operating pressure and SRV pressure setpoints. The change specified a highest allowable setpoint of 1115 11 psi and is still in effect at this time. All four SRV's are generally set within a range of approximately 1115 psig to 1120 psig. Analysis prepared by General Electric was submitted to support Amendment No. 73 and showed the existing performance characteristics of the HPCI and RCIC systems are sufficient to provide the system flow rates required by the Technical Specifications up to the higher SRV setpoints. Based on the change made to the l SRV setpoints by analysis and Amendment No. 73, the HPCI and RCIC system operating range upper l limit should be changed to 1126 psig to ensure pump testing demonstrates the required flow rates over J the full range of reactor pressure credited in safety analysis. .

150 Dsia Testina for HPCI and RCIC Systems 4

HPCI System The safety objective of HPCI is to provide core cooling following a small-break loss-of-coolant accident I (LOCA) in order to prevent core damage and the release of radioactive materials to the environs as a '

result of inadequate core cooling. The HPCI system also provides an alternate method of supplying makeup water to the reactor should the normal feedwater become unavailable.

Pilgrim Technical Specification section 3/4.5.C, "High Pressure injection System," provides actions (Limiting Conditions for Operation [LCO]) to be taken when the HPCI is degraded or inoperable and provides surveillance requirements and frequencies to ensure the availability of HPCI should plant l

conditions require its operation.

Section 4.5.C.1.d provides criteria for acceptable HPCI performance at the lower reactor pressure of 150 psig; that is, when the HPCI turbine is performing at lower pressures but is required to deliver 4250 GPM. Testing HPCI requires steam, which is generally supplied by the reactor. However, injecting coolant into the vessel, as would occur if HPCI was performing its safety objective, is undesirable during power operation. To allow HPCI testing with the reactor at power, a test line is provided. To simulate the major portion of the system resistance for the HPCI surveillance test at normal reactor I, Page 4 of 7 l

)

l pr:ssure, tho t:st line contains a restricting orifics. This restricting orifice rcducss the throttling duty of l the t:st line globe valve, reducing d: gradation of the valve. l Past practice at Pilgrim was to remove the restricting orifice from the test line when performing the 150 i psig test then reinstall it after successful completion of the test. In 1990-1991 time frame, engineering i studies were performed to develop alternate acceptance criteria based on pump affinity laws. The alternative acceptance criteria for the proposed equivalent testing will consist of a lower flow rate, turbine speed limit, and higher pump head, with the combination of the three parameters designed to demonstrate pump performance equal to or greater than that required to perform the safety function at 150 psig reactor pressure in terms of brake horsepower. Alternate pump test acceptance criteria such as this is based on basic engineering principles and provides a technically acceptable method to verify HPCI and RCIC performance at 150 psig. However, this practice did not result in a verbatim demonstration of a flow rate of 4250 gpm as specified in Pilgrim Technical Specification 4.5.C.1.d.

The proposed change will specifically allov; the use of an equivalent 150 psig test when the restricting orifice is installed re u!!ing in verbatim compliance. Use of the equivalent test for HPCI performance at 150 psig will verify HPCI to be operable and in compliance with its safety objective. Hence, operating Pilgrim in accordance with the proposed amendment results in satisfying the requirements of Technical Specifications and the HPCI system safety objective without impacting plant safety.

RCIC System The safety objective of RCIC is to provide a continuous supply of makeup water to the reactor core following reactor vessel isolation and when the normal feedwater system is unavailable. The pumping capacity of the RCIC system is sufficient to maintain the water level above the core without any other system available to supply water to the reactor core.

Correcting "HPCl" to "RCIC" in the heading of 4.5.D.1 is typographical and has no safety significance.

1 PilDrim Technical Specification section 3/4.5.D, " Reactor Core Isolation Cooling System," provides l actions (Limiting Conditions for Operation [LCO]) to be taken when the RCIC is degraded or inoperable I and provides surveillance requirements and frequencies to ensure the availability of RCIC should plant l conditions require its operation. l Section 4.5.D.1.d provides criteria for acceptable RCIC performance at the lower reactor pressure of 150 psig; that is, when the RCIC turbine is performing at lower pressures but is required to @!ver 400 GPM. Testing RCIC requires steam, which is generally supplied by the reactor. However, injecting coolant into the vessel, as would occur if RCIC was performing its safety objective, is undesirable during power operation. To allow RCIC testing with the reactor at power, a test line is provided. To simulate the major portion of the system resistance for the RCIC surveillance test at normal reactor pressure, the test line contains a restricting orifice. This restricting orifice reduces the throttling duty of the test line globe valve, reducing degradation of the valve.

Past practice at Pilgrim was to remove the restricting orifice from the test line when performing the 150 psig test then reinstallit after successful completion of the test. In 1990-1991 time frame, engineering studies were performed to develop alternate acceptance criteria based on pump affinity laws. The alternative acceptance criteria for the proposed equivalent testing will consist of a lower flow rate, turbine speed limit, and higher pump head, with the combination of the three parameters designed to demonstrate pump performance equal to or greater than that required to perform the safety function at 150 psig reactor pressure in terms of brake horsepower. Alternate pump test acceptance criteria such as this is based on basic engineering principles and provides a technically acceptable method to verify RCIC performance at 150 psig. However, this practice did not demonstrate a flow rate of 400 gpm as specified in Pilgrim Technical Specification 4.5.D.1.d.

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Th3 proposed chings will specifically tilow th3 uss of en equivil:nt 150 psig t:st wh:n tha restricting orifica is init;ll:d. Us3 of tha equivil:nt t:st for RCIC perform:nca et 150 prig will v:rify RCIC to be operable and in compliance with its safety objective. Hence, operating Pilgrim in accordance with the proposed amendment results in satisfying the requirements of Technical Specifications and the RCIC system. safety objective without impacting plant safety.

NO SIGNIFICANT HAZARDS CONSIDERATIONS In accordance with 10CFR50.91, Pilgrim has performed a no significance hazards analysis for the proposed changes to the HPCI and RCIC upper limit and 150 psig surveillance testing technical specifications and it is provided below.

• The operation of Pilgrim in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated.

Upper limit of HPCI and RCIC System Operatina Rance The increased upper limit in the operating pressure range for the HPCI and RCIC systems ensures pump testing demonstrates the maximum capability required by safety analysis. This change provides assurance of system capability over a wider range of reactor pressures and constitutes a more demanding test requirement for each system. Testing performed to these specifications will provide increased assurance of system capability and has no effect on the probability of occurrence or consequences of previously evaluated transients or accidents.

150 psia Testina for HPCI and RCIC Systems The proposed equivalent test to be used during the 150 psig test will demonstrate system operability.

The acceptance criteria consists of a lower flow rate, turbine speed limit, and higher pump head, with the combination of the three parameters designed to demonstrate pump performance equal to or greater than that required to perform the safety function at 150 psig reactor pressure in terms of brake horsepower. Alternate pump test acceptance criteria such as this is based on basic engineering principles and provides a technically acceptable method to verify HPIC and RCIC performance at 150 psig. Testing performed using the equivalent test will provide the required assurance of system capability and has no effect on the probability of occurrence or consequences of previously evaluated transients or accidents.

• The operation of Pilgrim in accordance with the proposed amendment will not create the possibility of a new or different kind of an accident from any accident previously evaluated.

The HPCI and RCIC system pumps are normally aligned to the condensate storage tanks and are tested by circulating water back to the tanks through a test line. This mode of testing is an original design feature of both systems as described in the Final Safety Analysis Report. The proposed increase to the upper limit in the operating range and the proposed equivalent 150 psig test affect the test acceptance criteria used in operability testing for the HPCI and RCIC systems but does not alter the basic method of testing. Testing performed using the proposed surveillance tests will provide the required assurance of system capability and will not create the possibility of a new or different kind of accident from any accident previously evaluated.

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l Page 6 of 7

e Th2 cperation cf Pilgrim in accordance with the proposed cmendment will n:t inv:lva a cignlNcant reduction in the margin cf safety.

The increased upper limit in the Technical Specification operating pressure range for the HPCI and RCIC systems ensures that pump testing demonstrates the maximum capability required by safety analysis. This change provides assurance of system capability over a wider range of reactor pressures and constitutes a more demanding test requirement for each system. Testing performed to these specifications will provide increased assurance of system capability and will not involve a reduction in the margin of safety.

The proposed equivalent test to be used during the 150 psig test will demonstrate system operability.

The acceptance criteria consists of a lower flow rate, turbine speed limit, and higher pump head, with the combination of the three parameters designed to demonstrate pump performance equal to or greater than that required to perform the safety function at 150 psig reactor pressure in terms of brake horsepower. Alternate pump test acceptance criteria such as this is based on basic engineering principles and provides a technically acceptable method to verify HPIC and RCIC performance at 150 psig. Testing performed in this way will provide the required assurance of system capability and will not involve a significant reduction in the margin of safety.

Environmental Consideration i

The proposed amendment changes the reactor head against which the HPCI and RCIC pumps must function. The proposed change will also allow an alternative testing methodology that is consistent with accepted engineering practice. Each proposed change is to be used when performing surveillance requirements with respect to facility components located within the restricted area as defined in 10 CFR Part 20. Pilgrim Nuclear Power Station has determined the amendment involves no significant increase in the amounts and no significant change in the types of any effluents that may be released offsite, and there is no significant increase in individual or cumulative occupational radiation exposure resulting from the implementation of this proposed change. Pilgrim has performed a no significant hazards consideration analysis (see above) and found the proposed amendment involves no significant hazards. Accordingly, Pilgrim submits the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Part 51.22(c)(9). Therefore, Pursuant to 10 CFR Part 51.22(b), Pilgrim concludes no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

SCHEDULE OF CHANGE This change will be implemented within 30 days following Pilgrim's receipt of its approval by the Commission.

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