Document Library

The following documents relate to the design of the San Onofre Nuclear Generating Station (SONGS) Replacement Steam Generators (RSGs). Southern California Edison (SCE) is making these documents available so that the facts relating to the design of the RSGs are publicly known.

Most Recent Documents

Paper on SCE - SCE's Decision to Retire San Onofre Units 2 & 3: Economic Considerations (11/13/2013)
Timeline (11/4/2013)
Paper on SCE - Mitsubishi Communications Related to Mitsubishi's Failed Efforts to Repair or Replace the Defective RSGs (11/4/2013)
SCE Response to Preliminary White Finding (10/29/2013)
Request for Arbitration (10/16/2013)
Mitsubishi Nuclear Energy Systems' Response to Sept. 30 Letter (10/16/2013)
SCE's Sept. 30 letter to Mitsubishi Nuclear Energy Systems, Inc. (10/7/2013)
Mitsubishi Nuclear Energy Systems' Response to Sept. 27 Letter (10/7/2013)
SCE's Sept. 27 letter to Mitsubishi Nuclear Energy Systems, Inc. (10/1/2013)
NRC Inspection Report Issued to SCE (9/20/13)
Inspection Report and Notice of Nonconformance Issued to Mitsubishi Heavy Industries (9/20/13)


Design Oversight Meetings between SCE and MHI from 2004-2009

During 2004 through 2009, SCE and MHI held meetings at which SCE reviewed MHI's design and fabrication activities related to the RSGs. SCE has provided a summary of the key issues addressed during those review meetings. Also, copies of the minutes of those meetings are provided. Note that some portions of the minutes have been redacted, and that the set of minutes is not complete. The redactions have been made by Mitsubishi Heavy Industries (MHI) in order to prevent public release of MHI's proprietary information. For the remaining sets of minutes (those not posted on this website), SCE is requesting that MHI agree that those minutes contain no MHI proprietary information, or to provide redacted versions so that they can be posted.

These materials were last updated on October 26, 2013.

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Screening and Evaluation Documents to Determine Need for NRC License Amendment

Screenings and Evaluations are conducted to determine whether or not a license amendment is needed when certain changes are made to a nuclear power plant.

Screenings are the first step in an assessment of a change under 10 CFR 50.59 to determine whether a license amendment is needed. A 50.59 Screening determines 1) whether there is a change to the Technical Specifications (which are part of the license); and 2) whether the design change affects a design function, method of performing or controlling the function, or an evaluation that demonstrates that intended functions will be accomplished, as described in the final safety analysis report. The purpose of a 50.59 Evaluation is to determine whether the changes meet any of eight criteria in 10 CFR 50.59(c) for a license amendment.

The following set of documents identifies the 50.59 Screenings and Evaluations that were performed for the San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 replacement steam generators.

These materials were last updated on September 4, 2013.

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Documents and Information Provided to the NRC

Below are documents and information that were provided by SCE to the NRC regarding the SONGS RSGs and design issues that caused the tube leak in one of the Unit 3 RSGs. Note that some documents have been redacted so that information proprietary to vendors of equipment and services to SONGS (such as MHI) is not released.

These materials were last updated on September 4, 2013.

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Presentations And Information

February 27, 2013
September 18, 2012
MHI Root Cause Eval And Supplemental Technical Evaluation Report Redacted
Root Cause Eval U2 SG R0 Final Redacted
Root Cause Eval U3 SG R0 Final Redacted

NRC Confirmatory Action Letter Response

SCE Cover Letter: Confirmatory Action Letter - Actions to Address Steam Generator Tube Degradation San Onofre Nuclear Generating Station, Unit 2
Enclosure 2: San Onofre Nuclear Generating Station Unit 2 Return to Service Report
Attachment 1: SONGS Unit 2 Relevant Technical Specifications
Attachment 2: AREVA Document 51-9182368-003 - SONGS 2C17 Steam Generator Condition Monitoring Report
Attachment 3: AREVA Document 51-9180143-001 - SONGS Unit 3 February 2012 Leaker Outage Steam Generator Condition Monitoring Report
Attachment 4: MHI Document L5-04GA564 - Tube Wear of Unit-3 RSG Technical Evaluation Report
Attachment 5: MHI Document L5-04GA571 - Screening Criteria for Susceptibility to In-Plane Tube Motion
Attachment 6: SONGS U2C17 - Steam Generator Operational Assessment
Attachment 6 - Appendix A: SONGS U2C17 Outage – Steam Generator Operational Assessment
Attachment 6 – Appendix B: SONGS U2C17 - Steam Generator Operational Assessment for Tube-to-Tube Wear
Attachment 6 – Appendix C: Operational Assessment for SONGS Unit 2 SG for Upper Bundle Tube-to-Tube Wear Degradation at End of Cycle 16
Attachment 6 – Appendix D: Operational Assessment of Wear Indications In the U-bend Region of San Onofre Unit 2 Replacement Steam Generators

Documents Provided to the NRC in Response to NRC Requests For Additional Information (RAI)

RAI 1
RAIs 2, 3 and 4
RAIs 5, 7 and 9
RAI 6
RAI 8
RAIs 10 and 17
RAI 11
RAI 12
RAI 13
RAI 14
RAI 15
RAI 16
RAI 18
RAI 19
RAIs 20, 21, 22, 23, 24, 26 and 31
RAI 25
RAI 27
RAI 28
RAI 29
RAI 30
RAI 32
RAIs 33, 34, 35, 36 and 55
RAIs 37 and 56
RAIs 38, 40, 41, 57, 59, 60 and 63-67
RAIs 39, 43, 44, 58 and 61
RAI 42
RAI 45
RAIs 46-49, 51 and 52
RAI 50
RAIs 53 and 72
RAI 54
RAI 62
RAIs 68, 69 and 70
RAI 71

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Design Specifications, Contracts and Correspondence

Design Specifications, Contracts, and Correspondence related to the SONGS RSGs are provided below. These include specifications requiring a design that would not permit the type of tube vibration that could cause a tube failure, and correspondence in which MHI was reminded by SCE that its design must prevent tube wear and tube failures.

These materials were last updated on October 29, 2013.

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Related Links


SONGS OII (CPUC) website