ML15089A595: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
 
Line 1: Line 1:
{{Adams
#REDIRECT [[DCL-15-040, Response to NRC Request for Additional Information Regarding Unit 1 Reactor Vessel Inspection Interval Extension from 10 to 20 Years]]
| number = ML15089A595
| issue date = 03/30/2015
| title = Response to NRC Request for Additional Information Regarding Unit 1 Reactor Vessel Inspection Interval Extension from 10 to 20 Years
| author name = Allen B S
| author affiliation = Pacific Gas & Electric Co
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000275
| license number = DPR-080
| contact person =
| case reference number = DCL-15-040
| document type = Letter
| page count = 4
}}
 
=Text=
{{#Wiki_filter:Pacific Gas and Electric Company March 30, 2015 PG&E Letter DCL-15-040 B arry S. Allen Vice President, Nuclear Services Diablo Canyon Power Plant Mail Code 104/6 P. 0. Box 56 Avila Beach, CA 93424 805.545.4888 Internal:
691.4888 Fax: 805.545.6445 Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 10 CFR 50.55a Docket No. 50-275, OL-DPR-80 Diablo Canyon Power Plant Unit 1 Response to NRC Request for Additional Information Regarding Unit 1 Reactor Vessel Inspection Interval Extension From 10 to 20 Years  
 
==References:==
: 1. 2. PG&E Letter DCL-14-074, "ASME Section Xllnservice Inspection Program Request for Alternative RPV-U 1-Extension to Allow Use of Alternate Reactor Inspection Interval Requirements," dated August 18, 2014 (ML 14230A618)
NRC Letter, "Diablo Canyon, Unit 1 -RAis for ASME Section XI lSI Program Request for Alternative RPV-U 1-Extension to Allow Use of *Alternate Reactor Inspection Interval Requirements (TAC No. MF4678)," dated February 24, 2014 Dear Commissioners and Staff: In Reference 1, Pacific Gas and Electric Company (PG&E) submitted Relief Request for NRC approval to extend the Diablo Canyon Power Plant (DCPP) Unit 1 reactor vessel inspection interval from 10 to 20 years in accordance with WCAP-16168-NP-A, Revision 3, "Risk-Informed Extension of the Reactor Vessel In-Service Inspection Interval." The NRC Staff provided a request for additional information (RAI) via an e-mail dated February 24, 2014 (Reference 2). The Enclosure to this letter provides PG&E's responses to the RAI questions.
This communication does not contain regulatory commitments (as defined by NEI 99-04). If you have any questions or require additional information, please contact Mr. Philippe Soenen at (805) 545-6984.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
* Diablo Canyon
* Palo Verde
* Wolf Creek Document Control Desk March 30, 2015 Page 2 Sincerely, Bar;;:z 5. Vice President-Nuclear Services rntU4231/50621143 Enclosure cc: Diablo Distribution cc/enc: Marc L. Dapas, NRC Region IV Administrator PG&E Letter DCL-15-040 Thomas R. Hipschman, NRC Senior Resident Inspector Siva P. Lingam, NRC Project Manager Gonzalo L. Perez, Branch Chief, California Department of Public Health State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
* Diablo Canyon
* Palo Verde
* Wolf Creek Enclosure PG&E Letter DCL-15-040 PG&E Response to NRC Request for Additional Information Regarding Relief Request REP-51 NRC Question RAI-1: Table 1, "Critical Parameters for the Application of Bounding Analysis for DCPP Unit 1 ,"states that DCPP Unit 1 is bounded by 7 heatup/cooldown cycles per year. Please cite the plant design basis for heatup/cooldown cycles per year. PG&E Response:
Table 5.2-4 in Updated Final Safety Analysis Report (UFSAR), Revision 21 lists the summary of all Reactor Coolant System (RCS) design transients, including the number of RCS heatup/cooldown design transients.
The 7 heatup/cooldown cycles per year (for a period of 80 years) assumed for the Westinghouse pilot plant study in WCAP-16168-NP-A, Revision 3 (Reference
: 1) provides a bounding fatigue crack growth value for the Diablo Canyon Unit 1 RCS design transients listed in UFSAR Table 5.2-4. The projected number of RCS transient cycles for 60 years of operation are provided in Table 4.3-2 of the Diablo Canyon Unit 1 License Renewal Application (Reference 2), which is less than the number of RCS design transients listed in UFSAR Table 5.2-4. Diablo Canyon Unit 1 is therefore bounded by the 7 heatup/cooldown cycles per year assumed for the Westinghouse pilot plant study in WCAP-16168-NP-A, Revision 3. NRC Question RAI-2: In Table 3, the licensee's calculated 11 T 3o, RT MAX-XX, and TWCF95-XX values were inconsistent with the calculations performed by the NRC staff. Please provide further detail on how 11T 30 was calculated.
In particular, please provide the Reactor Coolant System Temperature, P [wt%,], and Mn [wto/o] values used to perform the PG&E Response:
WCAP-16168-NP-A, Revision 3 (Reference
: 1) contains the U.S. NRC Safety Evaluation Report (SER) provided for the WCAP-16168-NP topical report. Paragraph 3.4, Item 1 of the U.S. NRC SER states the following:
1 Enclosure PG&E Letter DCL-15-040 The RT MAX-X and the shift in Charpy transition temperature produced by irradiation defined at the 30 ft-lb energy level, L1 T3o, must be calculated using the methodology documented in the latest revision of RG 1.99, "Radiation Embrittlement of Reactor Vessel Materials," or other NRC-approved methodology.
The 11 T 30 values for the Diablo Canyon Unit 1 reactor vessel materials were calculated using the Regulatory Guide (RG) 1.99, Revision 2 methodology (Reference 3). Specifically, the 11 T 30 values were determined per Equation 2 of RG 1.99, Revision 2: 11 T 30 = /1RT NDT = (CF) f 0'28-0.1 0iogf) The chemistry factor (CF) values are a function of copper and nickel content, and are provided in Table 3 of the request (Reference
: 4) for each of the materials.
The RCS temperature as well as the weight percent of phosphorus (P) and manganese (Mn) contents are not needed to calculate the 11 T 30 values in accordance with the RG 1.99, Revision 2. The neutron fluence (f) values used to calculate the 11 T 30 values for each of the materials are also provided in Table 3 of the request.
 
==References:==
: 1. Westinghouse Report WCAP-16168-NP-A, Revision 3, Informed Extension of the Reactor Vessel In-Service Inspection Interval," October 2011 (ADAMS Accession Number ML 11306A084)
: 2. "License Renewal Application Diablo Canyon Power Plant Unit 1 and Unit 2," Facility Operating License Nos. DPR-80 and DPR-82 (ADAMS Accession Number ML093340086)
: 3. NRC Regulatory Guide 1.99, Revision 2, "Radiation Embrittlement of Reactor Vessel Materials," U.S. Nuclear Regulatory Commission, May 1988 4. PG&E Letter DCL-14-074, "ASME Section Xllnservice Inspection Program Request for Alternative RPV-U 1-Extension to Allow Use of Alternate Reactor Inspection Interval Requirements," August 18, 2014 (ADAMS Accession Number ML 14230A618) 2}}

Latest revision as of 15:10, 7 April 2019

Redirect to:

Retrieved from "https://kanterella.com/w/index.php?title=ML15089A595&oldid=1420810"