ML17172A014

STP Response to ACRS Questions

ML17172A014
Person / Time
Site:	South Texas
Issue date:	05/04/2017
From:	Gonzales R South Texas
To:	Lois James Division of License Renewal
Lois M. James, 301-415-3306
References
CAC ME4936, CAC ME4937
Download: ML17172A014 (2)

Text

From: Gonzales, Rafael [1]

Sent: Thursday, May 04, 2017 10:11 AM To: James, Lois <Lois.James@nrc.gov>

Cc: Aldridge, Arden J <ajaldridge@STPEGS.COM>

Subject:

[External_Sender] STP response to ACRS questions

Lois, Below are responses to the questions from the ACRS subcommittee meeting:

Question 1: (ACRS Member Stetkar) What has the historic availability over the life of the plant of you cathodic protection system been?

Question 2: (ACRS Chairman Skillman) Based on the write up on page 287 of the SER, it was confusing as to whether or not there were vent valves on the aux feedwater pumps and were those vent valves within scope of license renewal?

Response to Question 1 The historical availability over the life of the plant of you cathodic protection system is as follows:

For the years 1988 to 1993, the data has been obtained from the preventive maintenances performed on al 16 rectifiers installed in the protected area. For the years 1994 to 2016, the data was obtained from 2 annual preventive maintenances (i.e. 93001319 and 94002738) performed on the system rectifiers to adjust/repair and pipetosoil potential surveys. It is best to consider the availability by individual year but the system maintained a lifetime average of 89.6%

availability.

Response to Question 2 There are no vent valves installed on the Unit 1 aux feedwater pumps. Unit 2 does have vent valves installed on the aux feedwater pumps. This was confirmed by reviewing site drawings, and by an actual field walk down.

Rafael Gonzales, P.E.

STPNOC, Licensing 361-972-4779