ML20063H732

LAR 94-001 to Licenses NPF-87 & NPF-89,revising TS by Increasing Unit 2 Boron Concentrations for RWST & ECCS Accumulators to Support Unit 2 Operation W/Extended Fuel Cycles

ML20063H732
Person / Time
Site:	Comanche Peak
Issue date:	02/14/1994
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20063H736	List: ML20063H732 ML20063H740
References
TXX-94007, NUDOCS 9402220163
Download: ML20063H732 (8)

Text

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r F ~""""" Log # TXX-94007 File # 916 (3/4.1)

Z C 916 (3/4.5) clo 7UELECTRIC 916 (3/4.9) clo ,

i 10010 l Ref. # 10CFR50.90 i mmam J. cahiii, Jr. 10CFR50.36 {

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l February 14, 1994 i

! U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 t

i

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) I DOCKET NOS. 50-445 AND 50-446  !

SUBMITTAL OF LICENSE AMENDMENT REQUEST 94-001 ,

INCREASE IN RWST AND ACCUMULATOR BORON CONCENTRATION FOR UNIT 2  !

REF: 1) TU Electric letter logged TXX-92469 from W. J. Cahill, Jr.,

to the NRC, dated October 19, 1992 l

2) NRC letter from Thomas A. Bergman to William J. Cahill, Jr.,

l dated October 5, 1993 l

l Gentlemen:

Pursuant to 10CFR50.90, TU Electric hereby requests an amendment to the CPSES Unit 1 and Unit 2 Operating Licenses (NPF-87 and NPF-89) by incorporating the attached changes into the CPSES Units 1 and 2 Technical Specifications.

The proposed changes revise the CPSES Units 1 and 2 Technical Specifications l by increasing the Unit 2 baron concentrations for the Refueling Water Storage Tank (RWST) and the Emergency Core Cooling System (ECCS)

Accumulators. These changes support Unit 2 operation with extended fuel cycles. The initial extended cycle for Unit 2 is currently planned for Cycle 2. These changes are applicable to Unit 2 only and are identical to those previously submitted and approved for Unit 1 (References 1 and 2). In addition, an administrative change deletes a footnote, concerning refueling canal boron concentration, which is no longer applicable. This administrative change is applicable to both units.

Attachment 2 provides a detailed description of the proposed changes, a safety analysis of the changes, and TU Electric's determination that the proposed changes do not involve a significant hazard consideration.

Attachment 3 provides the affected Technical Specification pages (NUREG-1468), marked-up to reflect proposed charges.

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TXX-94007 Page 2 of 2 i l

Since Cycle 2 for Unit 2 is presently scheduled for December 1994, TV Electric requests approval of this proposed license amendment by September 30, 1994, with implementation of the Technical Specification change to occur during the period following shutdown from Cycle 1 but prior to startup for Cycle 2. l In accordance with 10CFR50.91(b), TU Electric is providing the State of l Texas with a copy of this proposed amendment. )

Should you have any questions, please contact Mr. Bob Dacko at (214) 812-8228.

1 Sincerely,

/

p4 William J. ahill, Jr.

Group Vice President, Nuclear BSD Attachments: 1. Affidavit

2. Description and Assessment

3. Affected Technical Specification page (NUREG-1468) as revised by all approved license amendments c- Mr. L. J. Callan, Region IV Mr. T. A. Bergman, NRR Mr. L. A. Yandell, NRR Resident Inspectors, CPSES (2)

! Mr. D. K. Lacker Bureau of Radiation Control Texas Department of Public Health 1100 West 49th Street Austin, Texas 78704 l

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Attachment 1 to TXX-94007 Page 1 of 1 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of )

)

Texas utilities Electric Company ) Docket Nos. 50-445

) 50-446 (Comanche Peak Steam Electric ) License Nos. NPF-87 -

Station, Units 1 & 2) )_ -NPF-89 AFFIDAVIT l William J. Cahill, Jr. being duly sworn, hereby' deposes.and.says that he is.

Group Vice President, Nuclear for TU Electric,.the licenses herein; that-he is duly authorized to sign and file with the' Nuclear Regulatory Commission.

this License Amendment. Request 94-001; that'he is familiar with the content.

thereof; and that the matters set forth therein are true and correct to the, best of his knowledge, information and belief. #

l William J. cam ll, Jr.

Group Vice President, Nuclear STATE OF TEXAS )

)

COUNTY OF SOMERVELL)

Subscribed and sworn to before me, on this 14th day of- February .

1994. l otary Public PATRHM WILSON 1 MY COMMS$10N EXPlRES -

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l Attachment 2 to TXX-94007 Page 1 of 5 l DESCRIPTION AND ASSESSMENT l I. BACKGROUND l l i The intent of these changes is to allow for higher boron concentrations. l for the fluids in the Refteling Water Storage Tank (RWST) and Emergency l Core Cooling System (ECCS) Accumulators. These increases in boron ,

l concentration are necessary to accommodate the shutdown margin and

! safety analysis requirements associated with 18 month reload cycles. i l The changes as proposed will make the Unit 2 boron concentrations  !

! identical to the boron concentrations approved for Unit 1 in Reference 5.

II. DESM uTION OF TECHNICAL SPECIFICATIONS CHANGE REQUEST The proposed changes revise Technical Specifications (T/S.) 3/4.1.2.5,  !

3/4.1.2.6, 3/4.5.1, 3/4.5.4, and 3/4.9.1, and the BASES for 3/4.1 E, j 3/4.5.4, and 3/4.9.1. The changes increase the-Unit 2 boron j concentration of the flcid in the RWST to the range of 2400 to 2600 ppm,  !

in the ECCS Accumulators to the range of 2300 to 2600 ppm,.and the i minimum refueling operations boron concentration to 2400 ppm. In addition, a footnote is deleted from T/S 3/4.9.1.  ;

1 Specifically, T/S 3/4.1.2.5, 3/4.1.2.6 and 3/4.5.4 are revised to- l increase the minimum Unit 2 boron concentration for the RWST from 2000 to 2400 ppm. In addition, 3/4.1.2.6 and 3/4.5.4 are revised to increase the maximum Unit 2 boron concentration for the RWST from 2200 to 2600.

T/S 3/4.5.1 is revised to increase the allowed le  ? boron concentration range for the ECCS Accumulators fr A 300-2200 ppm to 2300-2600 ppm.

T/S 3/4.9.1 is revised to increase the Unit 2 minimum boron i concentration during refueling opratiuns for the Reactor Coolant System (RCS) and the refueling canal froc. 2000 ppm to 2400 ppm. In addition, as an administrctive change, the asterisk footnote concerning ,

limitations on refueling canal bo"on concentration during initial fuel load, is deleted.

T/S BASES 3/4.1.2 is revised to reflect the increased Unit 2 minimum boron concentration for the RWST.

T/l BASES 3/4.5.4 is revised to reflect the slight decrease in the bnit-2 minimum equilibrium Containment Sump solution pH (8.5 to 8.25) that results from the increased acidity of the more highly borated solutions.

T/S BASES 3/4.9.1 is revised to reflect the increased Unit 2 minimum boron concentration during refueling operations for.the_RCS and the refueling canal.

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l-Attachment 2 to TXX-94007 ,

Page 2 of 5 l III. ANALYSIS The changes to the CPSES Technical Specifications associated with this submittal involve an increase in the Unit 2 boron concentration of _

various fluids. The~ increased boron concentration _provides core ,

designers with necessary flexibility for. designing reload configurations '

for 18 month reload cycles while complying with the various safety ,

analyses requirements.

The increased boron concentration could potentially impact CPSES in several ways. Reviews were performed for'these var.ious impacts as follows:  ;

Changes in fluid chemistry and'the resultant impact on equipment  :

qualification and corrosion, j

- -The impact of a reduced minimum containment sump and spray pH on j the decontamination factor for off-site dose consequences, The impact of a lower pH on combustible gas proauction rate, The adequacy of the Emergency Boration System.to bring the plant i from full power.to hot standby with the requisite shutdown margin within a 90 minute period and to compensate for a complete xenon-decay in the next 90 minutes, '

The adequacy of post-LOCA sump. boron concentration to keep the reactor sub-critical during long term cooling,  ;

i The impact on hot leg. recirculation phase switchover time, l The affect on RWST boron re-crystallization, and  !

The impact on FSAR chapter 15 accii - analyses.

An analysis of the above impacts was performed for both CPSES Units 1 and 2. Because Unit 1 adopted the extended fuel cycle first, the request for an increase in the boron concentration was first submitted for Unit 1 (Reference 1). Additional information relating to the_ l request was provided in References 2, 3 and 4. The NRC approved the l Changes in Reference 5. The analysis of Unit 2 impacts is the same as l O y:ussed in those references (1 through 5). In addition, the. analysis i of the Boron Dilution event (which was addressed but not resolved in i Reference 1) was provided to the NRC by Reference 6. -The'NRC. approved.  !

the resulting boron dilution Technical Specification changes for both Units 1 and 2 in Reference 7.

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4 Attachment 2 to TXX-94007 Page 3 of 5 For each cycle of operation, the validity of the existing safety analyses is reconfirmed or a re-analysis is performed. Such a cycle-specific analysis is documented in the Reload Safety Evaluation.

In addition to the proposed changes to the Unit 2 allowable boron concentrations, the asterisk footnote for specification 3.9.1 is deleted. This footnote was applicable only during the initial fuel load of each unit. The initial fuel load is now complete for both units'and thus the footnote is no longer necessary. This is an administrative change and has no safety impact.

IV. SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION TU Electric has evaluated the significant hazards consideration involved with the proposed change by focusing on the three standards set forth in 10 CFR 50.92(c) as discussed below:

Does the proposed change:

1. Involve a significant increase in the probability or-consequences of an accident previously evaluated?

The proposed changes are related to the boron concentration in the Unit 2 RWST and ECCS Accumulators. The increased concentrations do not constitute a change expected to increase the probability of '

a previously evaluated accident.

Several mechanisms were identified by which the proposed changes might potentially increase radiological consequences of various accidents. These are summarized below:

Higher boron concentrations may result in increased probability of equipment failure by exposure to an environment more severe than its qualification environment.

Changes to containment spray and sump solution pH may adversely affect radioisotope removal and partition characteristics.

Changes in containment spray and sump solution pH may increase the containment combustible gases.

Higher baron concentrations could have an adverse impact on an inadvertent ECCS actuation.

The analyses of the above mechanisms indicated that there was no significant increase in the radiological consequences of any accident.

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Attachment 2 to TXX-94007 Page 4 of 5 The administrative change deleting'the asterisk footnote concerning refueling canal boron concentration'does not increaseL

.the probablity or consequences of:any accident.

.2. Create.the possibility of a new or different' kind of. accident'from any accident previously. evaluated?

The proposed changes are either administrative only'or are passive change associated with fluid ~ boron concentration. No new or.-

tifferent accident' sequences have.been identified.. Furthermore,"a review of heat tracing requirements'. indicates'that'there are no' additional requirements;resulting:from the' boron concentration. '

increase. There are no previously unconsidered failure, mechanisms.

3. . Include a significant reduction in the margin of safety?

The decrease in the containment spray and sump solution pH could be expected ~to result in higher. airborne' iodine concentrations.

The accident source terms could be impacted,by: variations in the iodine spray: removal and partition factors.; A comparison of the coefficients'for the. minimum equilibrium containment l sump solution pH to those used insthe CPSES design analyses, indicated thatLthe.

expected coefficient values would' remain bounded by the values:

used in the previous analyses. -Thus, no significant reduction in the margin'of. safety-has been identified as associated with-this phenomena.

The parameters contained.in the. Technical. Specifications'for which the changes are requested are used_when performing design analyses. In particular, these parameters are-used'for confirming-compliance of the core design with'the requirements. ..The changes requested are therefore not in themselves associated with any significant decrease in the margin of safety in'regards to the Chapter 15 analyses.

The administrative deletion of the asterisk footnote conCE ning refueling canal boron concentration has no impact on margin of- -

safety.

Based on the above evaluations, TV Electric concludes that the activities associated with the proposed changes ~ satisfy the.no-significant hazards consideration standards of 10CFR50.92(c)'and, accordingly, a no significant hazards consideration finding is justified.

I Mtachment 2 to TXX-94007 ,

Page 5 of 5 l V. ENVIRONMENTAL EVALUATION I l

l TU Electric has evaluated the proposed changes and has determined that'  !

l the changes do not involve (i) a significant' hazards consideration, (ii) l a significant change in the types or significant increase in.the amount  !

l of any effluent that may be released off-site, or (iii) a significant increase in individual or cumulative occupational radiation exposure. <

Accordingly, the proposed change meets the eligibility criterion for i categorical exclusion set forth in 10 CFR 51.22(c). Therefore, pursuant.

to 10 CFR 51.22(b), an environmental assessment of the proposed change l is not required.

i l VI. REFERENCES j

l 1. TU Electric letter logged TXX-92469 from W. E Cahill, Jr.,'to the .

NRC, dated October 19, 1992 l 2. TU Electric letter Logged TXX-93111 from W. J. Cahill, Jr., to the l NRC, dated March 17, 1993

3. TV Electric letter Logged TXX-93161 from W. J. Cahill, Jr., to the NRC, dated April 1, 1993 1

4. TV Electric letter Logged TXX-93288 ftam W. J. Cahill, Jr., to the NRC, dated August 6, 1993

5. NRC letter from Thomas A. Bergman to William J.'Cahill, Jr., dated October 5, 1993

6. TV Electric letter logged TXX-93098 from W. J. Cahill .Jr., to the NRC, dated April 30, 1993

7. NRC letter from Thomas A. Bergman to William J. Cahill, Jr., dated November 3, 1993 VII. PRECEDENTS CPSES Unit 1

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