NL-15-151, Watts Bar Nuclear Plant Unit 2 - Diesel Generator Frequency - Response to NUREG 0847 Supplemental Safety Evaluation Report (Sser) 22, Open Item 32 - Correction

Watts Bar Nuclear Plant Unit 2 - Diesel Generator Frequency - Response to NUREG 0847 Supplemental Safety Evaluation Report (Sser) 22, Open Item 32 - Correction

ML15208A113
Person / Time
Site:	Watts Bar
Issue date:	07/24/2015
From:	Shea J W Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-15-151, NUREG-0847
Download: ML15208A113 (4)

Text

m Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-15-151 July 24, 2015 U.S.Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.20555-0001 Watts Bar Nuclear Plant, Unit 2 Construction Permit No.CPPR-92 NRC Docket No.50-391 10CFR§50.4

Subject:

Watts Bar Nuclear Plant Unit2-Diesel Generator Frequency-Response to NUREG 0847 Supplemental Safety Evaluation Report (SSER)22, Open Item 32-Correction

References:

1.TVA LettertoNRC,"Watts Bar Nuclear Plant(WBN)Unit2-Diesel Generator Frequency-Response to NUREG 0847 Supplemental Safety Evaluation Report (SSER)22, OpenItem32," dated February 3, 2014 (ADAMS Accession Number ML14038A079)2.TVA LettertoNRC,"ApplicationtoModify Watts Bar Nuclear Plant,Unit1 Technical Specification

3.8.1 Regarding

Diesel Generator Steady State Frequency (WBN-TS-13-08)," datedApril6, 2015[ADAMS Accession No.ML081560183]

3.NRC Electronic Mail to TVA,"Draft REQUEST FOR ADDITIONAL INFORMATION MF6153.docx," datedMay28, 2015 The purpose of this letteristo correct information Tennessee Valley Authority (TVA)submitted on February 3, 2014 that supported a new allowable diesel generator frequency band for Watts Bar Nuclear Plant(WBN)Unit2 (Reference 1).Specifically, the values for brake horsepower at 60.2 hertz for major safety related pumps shown in Table5of Enclosure1of Reference 1 were slightly below the values in the design calculation.

U.S.NuclearRegulatoryCommission CNL-15-151 Page 2 July 24.2016 An application to modify the allowable diesel generator frequency band for WBN Unit 1wassubmittedby TVA on April 6, 2015 (Reference 2).During the Nuclear Regulatory Commission (NRC)reviewofReference2,thestaff identifiedthattherewasa difference between the values in Table5in the two submittals (Reference 3).The enclosuretothisletterprovidesanewReference1page E1-12 withacorrectedTable5for WBN Unit 2.The values shown in the revised Table 5 areidenticalto the values provided in Table 5 of theWBNUnit1 license amendment requesttomodify Technical Specification 3.8.1 (Reference2).Thedifferencebetweenthevaluesprovidedin Reference1andthe valuesprovidedInthisletter are veivsmallanddonot change the conclusions presentedinthe Reference1submittal.TheenrorinTable5of Reference 1 has been entered into the TVA con-ective action program.Ifyou have any questionsregardingthissubmittal, please contactGordonArentat (423)365-2004.There are no new regulatory commitmentsinthis submittal.

I declare under penalty of perjury that the foregoing is true and correct.Executed on the 24th day of July 2015./.Shea President, Nuclear Licensing

Enclosure:

Replacement Page El-12 cc (Enclosure):

NRC Regional Administrator

-Region II NRC Senior Resident Inspector-Watts Bar NuclearPlant,Unit2 NRC Project Manager-Watts Bar NuclearPlant,Unit2 Enclosure Replacement Page E1-12 Response to Supplemental Safety Evaluation Report (SSER)22, Open Item 32 increase in horsepower due to the increase in frequency is less than the nameplate rating times the service factor.Pump motor brake horsepower at higher speeds (+0.3%)will be slightly higher as follows: BHP2=1.010*BHPi Pump motor brake horsepower at lower speeds (-0.3%)will be slightly lower as follows: BHP2=0.990*BHPi The brake horsepowerwitha speed variationof+/-0.3%will vary by 1.0%.Table 5 provides a summary of the major pump brake horsepower.

Table5-Brake Horsepower Pump Normal/Accident Brake Horsepower (HP)Design Rated (@60.0 Hz Effective)

-0.3%(@59.8 Hz Effective)

+0.3%(@60.2 Hz Effective)

Name Plate (HP)AuxiliaryFeedWater"*601.5 595.6 607.5 600 Containment Spray 595.1 589.1 601.1 700 RHR 440.0 435.6 444.4 400 Safety Injection 453.4 448.9 457.9 400 Centrifugal Charging 695.0 688.1 702.0 600 ERCW" 805 797 813 800 Component Cooling-TrainsA&B and 2A-A 360*"(370)356"*(366)364"*(374)350**See Sections 1.2.5.1 and 1.2.5.2 for additional evaluation regarding temperature increase for these pump motors.***CCS Pump 2A-Aispemriittedto operateatflow rates resulting in excess of 360BHP(but less than 378BHP)for the operating range identified in Table 4 (Reference 2.3).All pumps have a slight increase/decrease in horsepower requirement; however, technical justification was provided for their acceptance (Reference 2.3): 1.TheRHR,SI, COS, and ERCW pump motors have a service factor of 1.15 and meet the standard acceptance criteria.E1-12