DCL-10-151, Response to Telephone Conference Call Held Nov. 9, 2010 Between Us Nuclear Regulatory Commission and Pacific Gas & Electric Co. Concerning Responses to Requests for Additional Information Related to License Renewal Application
| ML103300052 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/24/2010 |
| From: | Becker J Pacific Gas & Electric Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| DCL-10-151 | |
| Download: ML103300052 (7) | |
Text
Pacific Gas and Electric Company November 24, 2010 PG&E Letter DCL-1 0-151 u.s. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20852 Docket No. 50-275, OL-DPR-80.
Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 James R. Becker Site Vice President Diablo Canyon Power Plant Mail Code 104/5/601
- p. O. Box 56 Avila Beach, CA 93424 805.545.3462 Internal: 691.3462 Fax: 805.545.6445 Response to Telephone Conference Call Held on November 9, 2010, Between the U.S. Nuclear Regulatory Commission and Pacific Gas and Electric Company Concerning Responses to Requests for Additional Information Related to the Diablo Canyon Nuclear Power Plant. Units 1 and 2, License Renewal Application
Dear Commissioners and Staff:
By letter dated November 23, 2009 (Reference 1), Pacific Gas and Electric Company (PG&E) submitted an application to the U.S. Nuclear Regulatory Commission (NRC) for the renewal of Facility Operating Licenses DPR-80 and DPR-82, for Diablo Canyon Power Plant (DCPP) Units 1 and 2, respectively. The application included the license renewal application (LRA), and Applicant's Environmental Report - Operating License Renewal Stage.
On November 9, 2010 a telephone conference between the NRC and representatives of PG&E was held to obtain clarification on the applicant's response to request for additional information (RAI) submitted to the NRC in a letter dated September 22, 2010, regarding the detection of aging effects of the titanium components of the Open-Cycle Cooling Water System Aging Management Program. The telephone conference call was useful in clarifying the intent of
. PG&E's response.
PG&E's supplemental information to the RAI response for which the staff requested clarification, is provided in Enclosure 1.
PG&E has identified additional changes that are required in the LRA submitted in Reference 1. LRA Amendment 28 is included in Enclosure 2 showing the changed pages with line-inlline-out annotations.
PG&E revises previous commitments in Table A4-1, and makes no further commitments in this letter.
Document Control Desk November 24, 201 0 Page 2 PG&E Letter DCL-1 0-151 If you have any questions regarding this response, please contact Mr. Terence L. Grebel, License Renewal Project Manager, at (805) 545-4160.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on November 24, 2010.
TLG/50343158 Enclosure cc:
Diablo Distribution cc/enc: Elmo E. Collins, NRC Region IV Regional Administrator Nathanial Ferrer, NRC Project Manager, License Renewal Kimberly J. Green, NRC Project Manager, License Renewal Fred Lyon, NRC Project Manager, Office of Nuclear Reactor Regulation Michael S. Peck, NRC Senior Resident Inspector Alan B. Wang, NRC Project Manager, License Renewal
Enclosure 1 PG&E Letter DCL-10-151 Page 1 of 1 PG&E Supplement to Telephone Conference Call Held on November 9, 2010, Concerning Response to Request for Additional Information (RAI) Submitted to the NRC in a Letter Dated September 22, 2010, Regarding the detection of aging effects of the titanium components of the Open-Cycle Cooling Water System Aging Management Program.
PG&E letter dated September 22, 2010, provided information as to why cracking of the titanium instrument tubing and associated valves in the auxiliary saltwater (ASW) system is not likely to be induced. Described in the letter was how cracking of the components would be identified. PG&E stated that the first indication of cracking would be surface cracking, which would be detected by visual inspections. PG&E also committed to revising the DCPP external surfaces monitoring program to include visual inspections of the ASW system to inspect for cracking and leakage of the titanium tubing components.
During the telephone conference call on November 9, 2010, the NRC requested PG&E to provide the type of visual inspection techniques that will be used in the External Surface Monitoring Program to detect cracks in titanium prior to failure (i.e., leakage).
PG&Es Response:
Further investigation of the specific material type of the titanium determined that the grade of titanium used in the auxiliary saltwater (ASW) system is either AMS 4943 or ASTM B 338 GR 1. These titanium grades are not susceptible to stress corrosion cracking in raw water operating environments. Based on these findings, there are no aging effects on the titanium components requiring aging management. Therefore, no aging management program and no visual inspections are required for these components. PG&E has revised Table A4-1 to delete the commitment to enhance the external surfaces monitoring program to include visual inspections of the ASW system to inspect for cracking and leakage of the titanium tubing components. See revised License Renewal Application Section 3.3.2.1.3, Table 3.3.2-3 and Table A4-1 in.
PG&E Letter DCL-10-151 Page 1 of 4 LRA Amendment 28 LRA Section Section 3.3.2.1.3 Table A4-1 Table 3.3.2-3 Section 3.3 PG&E Letter DCL-10-151 AGING MANAGEMENT OF AUXILIARY SYSTEMS Page 2of 4 3.3.2.1.3 Saltwater and Chlorination System Materials The materials of construction for the saltwater and chlorination system component types are:
Titanium (Grade 9) (Grade of titanium is either AMS 4943 or ASTM B 338 GR 1,)
Aging Effects Requiring Management The following saltwater and chlorination system aging effects require management:
Cracking Appendix A PG&E Letter DCL-10-151 FINAL SAFETY ANALYSIS REPORT SUPPLEMENT Page 3 of 4 Table A4-1 License Renewal Commitments Item #
Commitment LRA Section Implementation Schedule 37 The DCPP external surfaces monitoring program will be revised to include visual inspections of the ASW system to inspect for cracking and leakage of the titanium tubing components in scope for license renewal at intervals no longer than once per refueling cycle.
B2.1.20 Prior to the period of extended operation Section 3.3 PG&E Letter DCL-10-151 AGING MANAGEMENT OF AUXILIARY SYSTEMS Page 4 of 4 Table 3.3.2-3 Auxiliary Systems - Summary of Aging Management Evaluation - Saltwater and Chlorination System Component Type Intended Function Material Environment Aging Effect Requiring Management Aging Management Program NUREG-1801 Vol.
2 Item Table 1 Item Notes Tubing PB Titanium (Grade 9)
Plant Indoor Air (Ext)
None None None None F, 2 Tubing PB Titanium (Grade 9)
Raw Water (Int)
Cracking None Open Cycle Cooling Water System (B2.1.9)
None None None F, 2 Valve PB Titanium (Grade 9)
Plant Indoor Air (Ext)
None None None None F, 2 Valve PB Titanium (Grade 9)
Raw Water (Int)
Cracking None Open Cycle Cooling Water System (B2.1.9)None None None F, 2 Plant Specific Notes:
2 Titanium grade is either AMS 4943 or ASTM B 338 GR 1, neither of which are susceptible to stress corrosion cracking under operating environments specified in the table.