ML15252A401

License Amendment Request Regarding Non-Conservative Technical Specification Allowable Value

ML15252A401
Person / Time
Site:	Catawba
Issue date:	09/17/2015
From:	Geoffrey Miller Plant Licensing Branch II
To:	Henderson K Duke Energy Carolinas
Miller G
References
TAC MF5293, TAC MF5294
Download: ML15252A401 (4)

Text

~f>.R REG(J c> {.</

/~~: -

_"'011_,_

0 UNITED STATES

~ ~~

-, - _- 0

~

NUCLEAR REGULATORY COMMISSION

_*.. . .- I WASHINGTON, D.C. 20555-0001

~~

/1' .f?

f) ~o

• • • 11~

September 17, 2015 Mr. Kelvin Henderson Site Vice President Catawba Nuclear Station Duke Energy Carolinas, LLC 4800 Concord Road York, NC 297 45

SUBJECT:

CATAWBA NUCLEAR STATION, UNITS 1 AND 2: LICENSE AMENDMENT REQUEST REGARDING NON-CONSERVATIVE TECHNICAL SPECIFICATION ALLOWABLE VALUE (TAC NOS. MF5293 AND MF5294)

Dear Mr. Henderson,

By letter dated November 24, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14330A327), Duke Energy Carolinas, LLC, submitted a license amendment request for the Catawba Nuclear Station, Units 1 and 2. The proposed amendment would revise the allowable value in the subject Technical Specifications to correct a non-conservative value.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the submittal and determined that additional information is needed in order to complete the NRC staff's review.

Enclosure 1 describes this request for additional information.

If you have any questions, please call me at 301-415-2481.

Sincerely, , ,)

&*J/t._,

G. Edward Miller, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-413 and 50-414

Enclosure:

As stated cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING CATAWBA NUCLEAR STATION. UNITS 1 AND 2 LICENSE AMENDMENT REQUEST TS 3.3.2, "ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION" TS 3.3.5, "LOSS OF POWER DIESEL GENERATOR STARTUP INSTRUMENTATION" DOCKET NOS. 50-413 AND 50-414 By letter dated November 24, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14330A327), Duke Energy Carolinas (Duke) submitted a license amendment request for the Catawba Nuclear Station, Units 1 and 2. The proposed amendment would revise the allowable value in the subject Technical Specificaitons to correct a non-conservative value. In order for the U.S. Nuclear Regulatory Commission (NRC) staff to complete its review of the relief request, the following additional information is requested.

1. By letter dated August 17, 2015 (ADAMS Accession No. ML15231A012), Duke provided a response to NRC RAI No. 6, which requested a curve showing the voltage transient associated with the starting of loss-of-coolant accident loads after receipt of a safety injection signal. Please provide the following clarifications:

a. The figure for Unit 2 shows a voltage transient at 21.9 seconds that your response characterized as the switching on and off of loads used to create bounding voltages for the 600 V system. Further, the response indicates that it would not be reflective of an actual transient. Please provide additional clarification of the cause of this transient.

b. The response further stated that based on Unit 2 figure, the degraded grid voltage relay would not be capable of resetting due to the degraded grid timer timing out prior to the voltage recovering above the reset voltage. The response indicates that this is due the fact that the 4.16 kV motor start times have been increased to take into account timer tolerances and additional conservatism.

This was done to ensure that the worst case motor operated valve voltage is determined. Please explain the tolerances and conservatism assumed in the motor start times or clarify its response.

Enclosure

c. The response stated that the lowest voltage occurs when the containment spray pump starts concurrently with auxiliary feedwater pump motor. However, automatic starting of containment spray motors have been deleted as part of Emergency Core Cooling System Water Management license amendment (Amendments 257/252 for Units 1 and 2, respectively). Please confirm that auxiliary feedwater pump motor and containment spray pump motors will not start simultaneously based on the amendments 257/252 approved by NRC on June 28, 2010 (ADAMS Accession No. ML092530088).

d. Please discuss any impact on the Unit 2 voltage-time curve as a result of the above clarifications.

ML15252A401 OFFICE NRR/LPLl-1/PM NRR/LPL2-1 /LA NRR/DE/EEEB/BC NRR/LPL2-1 /BC NAME GEMiller SFigueroa JZimmerman RPascarelli DATE 09/06/15 09/14/15 09/16/15 09/17/15