ML20085L110

Application for Amend to License NPF-86.Amend Would Increase Requirements for Core Reactivity Control Available from Borated Water Sources

ML20085L110
Person / Time
Site:	Seabrook
Issue date:	06/16/1995
From:	Feigenbaum T NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO), NORTHEAST UTILITIES SERVICE CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20085L113	List: ML20085L110 ML20085L116
References
NYN-95051, NUDOCS 9506280304
Download: ML20085L110 (9)

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ATnOr(L11 P.O. sox 300 North Atlantic Energy Service Corporation Atlantic Seabrook NH 03874 0

(603) 474-9521, Fax (603) 474-2987 The Northeast Utilities Systern Ted C. Feigenbaurn Senior Vice President &

Chief Nuclear Officer NYN-95051 June 16,1995 United States Nuclear Regulatory Commission Washington, D.C. 20555 Attention:

Document Control Desk

Reference:

Facility Operating License No. NPF-86, Docket No. 50-443

Subject:

License Amendment Request 95-01: Borated Water Sources (TAC No. 92007)

Gentlemen:

North Atlantic Energy Service Corporation (North Atlantic) has enclosed herein License Amendment Request 95-01. This License Amendment Request (LAR) is submitted pursuant to the requirements of 10CFR50.90 and 10CFR50.4.

The purpose of LAR 95-01 is to propose changes to the Seabrook Station Technical Specifications to increase the requirements for core reactivity control available from borated water sources. The increased requirements for boron concentration in borated water sources assure that sufficient negative reactivity remains available to ofTset the design increase in positive core reactivity beginning with Cycle 5.

LAR 95-01 has been reviewed and approved by the Station Operation Review Committee and the Nuclear Safety Audit Review Committee. A similar change was issued to Millstone Unit 3 as Amendment Number 60 to operating license number NPF-49, in response to their cycle 4 reload application.

As discussed in the enclosed LAR Section IV, the proposed changes do not involve a significant hazard consideration pursuant to 10CFR50.92. A copy of this letter and the enclosed LAR have been forwarded to the New Ilampshire St#: Liaison Oflicer pursuant to 10CFR50.91(b). In addition, North Atlantic has determined that LAR 95-01 meets the criteria of 10CFR51.22(c) for a categorical exclusion from the requirements for an Environmental Impact Statement (see Section VI enclosed).

North Atlantic requests NRC review of LAR 95-01 and issuance of a license amendment by November 1,1995 (see Section V enclosed).

260024 d0 i 9506280304 950616 s

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. United States Nuclear Regulatory Commission June 16,1995 Attention:

Document Control Desk Page two Should you have any questions regarding this letter, please contact Mr. James M. Peschel, Regulatory Compliance Manager, at (603) 474-9521, extension 3772.

Very ly yours, g;;% fr Ted C. Feigenbaum Enclosure cc:

Mr. Thomas T. Martin Regional Administrator United States Nuclear Regulatory Commission Region 1 475 Allendale Road King of Prussia, PA 19406 Mr. Albert W. De Agazio, Sr. Project Manager Project Directorate I-4 Division of Reactor Projects U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. John Macdonald NRC Senior Resident Inspector P.O. Box 1149 Seabrook, Nil 03874 Mr. George 1,. Iverson, Director New ilampshire Office of Emergency Management 107 Pleasant Street Concord, NII 03301 4

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North h//jj Atlantic SEABROOK STATION UNIT 1 Facility Operating License NPF-86 Docket No. 50-443 License Amendment Request No. 95-01 Borated Water Sources This License Amendment Request is submitted by North Atlantic Energy Service Corporation pursuant to 10CFR50.90. The following information is enclosed in support of this License Amendment Request:

Section 1 Introduction and Safety Evaluation for Proposed Changes Section 11 Markup of Proposed Changes Section 111 Retype of Proposed ChangesSection IV Determination of Significant Hazards for Proposed ChangesSection V Proposed Schedule for License Amendment issuance and Effectiveness j

l Section VI EnvironmentalImpact Assessment Sworn and Subscribed to before me thi

//p A day of

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,1995 hNh(jff' $$11/7W ifr6ce L. Drawbridge /

Notary Public Executive Director - Nuclear roduction l

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• • Introduction and Safety Evaluation for Proposed Chances A.

Introduction The purpose of License Amendment Request (LAR) 95-01 is to propose changes to the Seabrook Station Technical Specifications to increase the requirements for core reactivity control available from borated water sources. The increased requirements for boron concent Jtion in borated water sources assure that sefficient negative reactivity remains available to offset the design increase in positive core reachity beginning with Cycle 5. The design increase in positive core reactivity c.*ises from. ihe increased cycle length.

The affected borated water sources include:

1)

The Refueling Water Storage Tank (RWST) for all Modes of operation; and 2)

The Emergency Core Cooling System (ECCS) Accumulators when required to be operable.

For Cycle 5, the existing 10CFR50.46 requirement for post-LOCA suberiticality and long term cooling establishes the need for increased reactivity control from the RWST and the Accumulators. Current concentration requirements in all other borated water sources were reviewed and found to meet the reactivity control requirements of the Cycle 5 design.

The proposed increase in the required boron concentrations in the RWST and Accumulators required a review of the NaOli inventory in the Spray Additive Tank (SAT). This inventory assures an acceptable range of pil of between 8.5 and 11.0 for the solution recirculated within containment after a Loss of Coolant Accident (LOCA). This review determined that changes to the NaOli inventory are not required.

The increase in the required boron concentrations necessitates a change in the post-LOCA hot leg recirculation initiation time to prevent boron precipitation. This switchover time is presently 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> and appears in Section 6.3 of the Seabrook Station Updated Final Safety Analysis Report (UFSAR) and in Emergency Response Procedures (ERPs) E-1,1,oss of Reactor or Secondary Coolant, and ES-1 A, Transfer to liot Lee Recirculation. The increase in the required boron concentrations requires a switchover time of 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> to prevent the core region from reaching the boron precipitation limit. The available hot leg recirculation flow is sufficient to remove decay heat at 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />. Therefore, a hot leg recirculation time of 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> post-LOCA is acceptable.

The combination of proposed changes to Technical Specifications and Bases will assure that sufficient core reactivity control remains available during the operation of Cycle 5 and subsequent cycles. The proposed upper limit on boron concentration in the RWST and Accumulators also ensures that the boron solubility limit will not be approached in these volumes. Boron concentrations in borated water sources and containment sump pil after a LOCA are calculated using existing analysis methodology. The post-LOCA time for switchover to hot leg recirculation is changed to assure the core region will not reach the boron precipitation limit.

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• Safety Evaluation of Proposed Changes This section describes the safety evaluation of the proposed changes to the Facility Operating License to assure that sufficient core reactivity control remains available during the operation of Cycle 5 and subsequent cycles. In summary, the proposed changes affect:

a)

TechnicalSpeci/lcation 3.1.2.5, Borated Water Sources - Shutdown; l

b)

TechnicalSpecvication 3.1.2.6, Borated Water Sources - Operating; c)

TechnicalSpecification 3.5.1.1, Accumulators; and d)

Technical Specification 3.5.4, RWST - Boron injection System.

l A safety evaluation of each proposed changes is provided below The proposed changes are also summarized in Table 1.

For completeness, the safety evaluation includes a discussion of potentially affected Technical Specifications for which no changes are proposed. Markups of the proposed changes to TechnicalSpecifications and Bases, are provided later in Cection 11 of this LAR.

1.

TechnicalSt>eci/lcation 3.1.1.2. Mode 5 Shutdown Marcin Technical Specification 3.1.1.2 currently requires that the Reactor Coolant System boron i

concentration shall be greater than or equal to 2000 ppm boron when the reactor coolant loops l

are in a drained condition. The basis for this requirement is to permit sufficient time for the operator to terminate an inadvertent boron dilution event with T,y less than 200 F. The current boron concentration requirement exceeds the requirements for acceptable boron dilution accident j

analysis results for Cycle 5. So, a change to the required boron concentration is not proposed.

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Technical St>cci/? cation 3.1.2.5. Borated Water Sources - Shutdown Technical Specification 3.1.2.5 requires that either the Boric Acid Storage Tank (BAST) or the l

Refueling Water Storage Tank (RWST) be operable in Modes 5 and 6.

The basis for the minimum contained water volumes and minimum boron concentrations is to provide the shutdown margin specified in the Core Operating Limits Report (COLR) after xenon decay and cooldown from 200 F to 140 F. The contained volumes include allowance for unusable volumes because of discharge line location and other physical characteristics. The current boron concentration l

requirement for the BAST exceeds the predicted shutdown margin requirements for Cycle 5 and other future cycles. So, a change to the BAST boron concentration requirement is not proposed.

The current RWST boron concentration requirement of 2000 ppm is increased to 2700 ppm where the value appears in the Limiting Conditionfor Operation and Bases. The proposed value of 2700 ppm exceeds the predicted shutdown margin requirements for Cycle 5 and other future cycles.

The proposed value is consistent with the proposed changes to TechnicalSpecifications 3.1.2.6 and 3.5.4 discussed below.

Affects: Technica/ Specifications pages 3/41-11 and B 3/41-3 t

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Technical Sticci/lcation 3.1.2.6. Borated Water Sources - Oneratina TechnicalSpecification 3.1.2.6 requires that either the Boric Acid Storage Tank (BAST) or the Refueling Water Storage Tank (RWST) be operable in Modes 1 to 4. The basis for the minimum contained water volumes and minimum boron concentrations is to provide the shutdown margin specified in the COLR from expected operating conditions after xenon decay and cooldown to 200 F. The contained volumes include allowance for unusable volumes because of discharge line location and other physical characteristics. The limits on contained water volume and boron concentration of the RWST also ensure an acceptable range of pli of between 8.5 and 11.0 for the solution recirculated within containment afler a LOCA. The current boron concentration requirement for the BAST exceeds the predicted shutdown margin requirements for Cycle 5 and other future cycles. So, a change to the BAST boron concentration requirement is not proposed.

The current minimum RWST boron concentration requirement of 2000 ppm is changed to a required range of 2700 to 2900 ppm where the value appears in the Limiting Condition for Operation and Bases. The proposed range of RWST boron concentration:

a) exceeds the predicted shutdown margin requirements for Cycle 5 and other future cycles; b) ensures an acceptable range of pil for the solution recirculated within containment after a LOCA; c) ensures that the boron solubility limit will not be approached in the RWST.

The proposed change is also consistent with the proposed changes to Technical Specifications 3.1.2.5 and 3.5.4.

Affects: Technica/ Specifications pages 3/41-12 and B 3/41-2 4.

Technical St>eci/lcation 3.5.I.1. Accumulators Technical 4>ccification 3.5.1.1 requires that the accumulators be operable with a boron concentration range of 1900 to 2l00 ppm during Modes I to 3. The basis for the limits on boron concentration is to ensure that the assumptions used for accumulator injection in the safety I

analysis are met. The current required range of boron concentration in the accumulators is changed for Cycle 5 and other future cycles to a required range of 2600 to 2900 ppm as it appears in the Limiting Conditionfor Operation. The proposed upper limit on boron concentration in the Accumulators ensures that the boron solubility limit will not be approached in these volumes.

This change together with the proposed change to TechnicalSpecylcation 3.5.4, RWST - Boron injection System, ensures that following a LOCA:

1) the core remains suberitical in the cold condition and amenable to long term cooling:

2) the range of pil for the solution recirculated within containment remains acceptable; and, 3) the switchover from cold leg to hot leg recirculation at 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> is acceptable.

Affects: TechnicalSpecifications page 3/4 5-1

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Technical Speci/ication 3.5.4. RWST - Boron Iniectan System Technical Specification 3.5.4 currently requires that the RWST be operable in Modes 1 to 4 with a minimum boron concentration of 2000 ppm of boron. The basis for the limit on boron concentration is to ensare that following a LOCA,1) the core remains subcritical in the cold condition and amenable to long term cooling, and 2) the range of pli of between 8.5 and 11.0 for the solution recirculated within containment remains acceptable. The current required minimum boron concentration in the RWST is changed for Cycle 5 and other future cycles to a required range of 2700 to 2900 ppm as it appears in the Limiting conditionfor Operation. The proposed upper limit on boron concentration in the RWST ensures that the boron solubility limit will not he approached in this volume. This change together with the proposed change to Technical Specification 3.5.1.1, Accumulators, ensures that following a LOCA:

i 1) the core remains subcritical in the cold condition and amenable to long term cooling; 2) the range of pil for the solution recirculated within containment remains acceptable; 3) the switchover from cold leg to hot leg recirculation at 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> is acceptable.

Affects: TechnicalSpecylcations page 3/4 5-11 6.

TechnicalSpecification 3.6.2.2. Spray Additive Tank TechnicalSpecification 3.6.2.2 currently requires that the Spray Additive Tank (SAT) be operable with a contained volume between 9420 and 9650 gallons of between 19 and 21% by weight NaOli solution in Modes I to 4. The limits on NaOli volume and concentration ensure a pli value of between 8.5 and 11.0 for the solution recirculated within containment after a LOCA.

The limits on contained solution volume include an allowance for solution not usable because of tank discharge line location and other physical characteristics. The effect of the proposed changes i

to boron concentrations in the Accumulators (Technical Specification 3.5.1.1) and RWST (Technical Specification 3.5.4) on the post-LOCA sump pil was re-evaluated consistent with the i

methodology described in UFSAR Section 6.2.2.2. In conclusion, the current limits on NaOli inventory in the SAT ensure an acceptable range of pli for the solution recirculated within containment after a LOCA. No change to the SAT is proposed.

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Technical Specification 3.9.l. Refueline Boron Concentration Technical Specification 3.9.1 currently requires during Mode 6 (refueling) that 1) k, s; 0.95 or

2) the boron concentration in all filled portions of the RCS and the refueling canal be 2 2000 ppm, whichever is more restrictive. The basis for these limitations is to assure consistency with initial conditions assumed for the boron dilution incident in the safety analyses. The current boron concentration requirement exceeds the requirements for acceptable boron dilution accident analysis results for Cycle 5. No change to the required boron concentration is proposed.

For convenience, the proposed changes described above are also summarized in Table 1.

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TABLEI LAR 95-01: IlORATED WATER SOURCES TECII. SPEC.

AFFECTED CURRENT TECIINICAL SPECIFICATION PROPOSED NUMBER PARAMETER VALUE HASIS CIIANGE 3.1.2.5 Minimum 2000 ppm The RWST is an alternate borated water Change value Borated Water RWST C, source sufficient to provide the to: 2700 ppm Sources shutdown margin specified in the COLR Modes 5,6 after xenon decay and cooldown from (Shutdown) 200 F to 140 F.

3.1.2.6 Minimum 2000 ppm The RWST is an alternate borated water Change value Borated Water RWST C, source sufficient to provide the to: 2700 to Sources shutdown margin specified in the COLR 2900 ppm.

Modes I to 4 from expected operating conditions after (Operating) xenon decay and cooldown to 200 F.

The limits on contained water volume and C, of the RWST ensure a sump pil between 8.5 and 11.0 after a LOCA.

3.5.1.1 C, limits 1900 to The limits on contained water volume, Change range Accumulators 2l00 ppm C,, and pressure ensure that the to: 2600 to assumptions for accumulator injection in 2900 ppm the safety analysis are met.

3.5.4 Minimum C, 2000 ppm The limits on contained water volume Change value RWST - lloron and C, ensure 1) adequate recirculation to: 2700 to injection System cooling flow to the core,2) a suberitical 2900 ppm.

Modes 1 to 4 core in the cold condition and amenable to long term cooling, and 3) a sump pil I

between 8.5 and 11.0 after a LOCA.

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Markup of Proposed Chances The enclosed markup pages reflect the currently issued version of Technical Specifications and Bases and include the changes approved in License Amendment No. 33, Wide-Band Operation and Core Enhancementso2). Revision bars are provided in the right margin to designate a change in the text, (1) lener from A.W. De Agazio (USNRC) to T.C. Feigenbaum (NAESCo), Amendment No. 33 to Facility Oncratine I icense b F-8& Wide-Rand Oncration and Core Fnhancements - 1,icense Amendment Request 93-18 (TAC M87849), November l

23,1994.

(2) letter from A.W. De Agazio (USNRC) to T.C. Feigenbaum (NAESCo), Correction to Amendment 33 to Facility Oncratine Iicense NPF-86 (TAC M87849). December 6,1994.

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