ML103620556

Request for Additional Information, Relief Request RR-ENG-3-02

ML103620556
Person / Time
Site:	South Texas
Issue date:	12/28/2010
From:	Thadani M Plant Licensing Branch IV
To:	Harrison A, Walker P South Texas
Thadani, M C, NRR/DORL/LP4, 415-1476
Shared Package
ML103620550	List: ML103620556
References
TAC ME4764, TAC ME4765
Download: ML103620556 (1)

Text

REQUEST FOR ADDITIONAL INFORMATION 3RD 10-YEAR INTERVAL RELIEF REQUEST RR-ENG-3-02 SOUTH TEXAS PROJECT UNITS 1 AND 2 STP NUCLEAR OPERATING COMPANY DOCKET NUMBERS 50-498 AND 50-499 The Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by STP Nuclear Operating Company for South Texas Project Units 1 and 2, in its letter dated September 20, 2010, and has determined that additional information is necessary to complete the review of Relief Request RR-ENG-3-02. Based on the staff=s review, please address the following questions.

1. Please provide the start and end dates of the third 10-year inservice inspection interval for STP Units 1 and 2.

2. Section E of RR-ENG-3-02 states that the straight beam ultrasonic examination procedure has been demonstrated to ensure examination adequacy. Please provide a detailed description of this demonstration, including mockups/samples used, method(s) demonstrated, and results.

3. What flaws are expected in these components? Unless addressed in response to question 2 above, please address whether the mockups used in the demonstration of the UT technique contained flaws representative of those found inservice.

4. The illustration of the Roto-lok flange insert provided in RR-ENG-3-02 is not sufficient for understanding the Code-required examination surface as well as what is going to be examined with UT in lieu of VT. Please provide additional illustrations to clarify the Code required VT and proposed UT examination.

5. How many Roto-Lok flange inserts are on each reactor vessel?