IR 05000206/1990036
| ML13316A069 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/24/1990 |
| From: | Johnson P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML13316A068 | List: |
| References | |
| 50-206-90-36-MM, 50-361-90-36, 50-362-90-36, NUDOCS 9011150073 | |
| Download: ML13316A069 (41) | |
Text
U.S. NUCLEAR REGULATORY COMMISSION
REGION V
Report No /90-36, 50-361/90-36, 50-362/90-36 Docket No, 50-361, 50-362 License No DPR-13, NPF-10, NPF-15 Licensee:
Southern California Edison Company Irvine Operations Center 23 Parker Street Irvine, California 92718 Facility Name:
San Onofre Units 1, 2 and 3 Meeting at:
San Clemente, California Meeting conducted: September 25, 1990 Prepared by:
David L. Solorio, Inspector Inter Approved By:
_o_____
P. H. o nson, Chief Date Signed React Projects Section 3 Summary A Management Meeting was held on September 25, 1990 to discuss recent experience on erosion and corrosion of piping systems, reverification of the Unit 1 single failure analysis, revalidation of the environmental qualifica tion program, Unit 1 safety injection system status, and the root cause analysis program. In addition, the licensee provided an update on the design basis documentation (DBD) revie PO1029
DETAILS 1. Meeting Participants Nuclear Regulatory Commission J. B. Martin, Regional Administrator R. P. Zimmerman, Director, Division of Reactor Safety and Projects K. E. Perkins, Deputy Director, Division of Reactor Safety and Projects F. A. Wenslawski, Deputy Director, Division of Radiation Safety and Safeguards P. H. Johnson, Chief, Reactor Projects Section 3 R. F. Huey, Chief, Engineering Section C. W. Caldwell, Senior Resident Inspector J. E. Tatum, Unit 1 NRR Project Manager L. E. Kokajko, Units 2 and 3 NRR Project Manager A. L. Hon, Resident Inspector, San Onofre C. D. Townsend, Resident Inspector, San Onofre D. L. Solorio, Inspector Intern Southern California Edison Company H. B. Ray, Senior Vice President, Nuclear H. E. Morgan, Vice President and Site Manager R. W. Krieger, Station Manager B. Katz, Manager, Nuclear Oversight J. T. Reilly, Manager, Nuclear Engineering and Construction R. M. Rosenblum, Manager, Nuclear Regulatory Affairs M. L. Merlo, Nuclear Engineering Design Manager R. W. Waldo, Operations Manager M. P. Short, Technical Manager R. 0. Lacy, Manager, Nuclear, San Diego Gas & Electric 2. Management Meeting Background On September 25, 1990, a Management Meeting was held at San Onofre Nuclear Generating Station (SONGS) at San Clemente, California among the individuals identified in Paragraph 1. The purpose of this meeting was to discuss recent findings related to erosion and corrosion of piping systems, the Unit 1 single failure analysis recently performed by the licensee, environmental qualification program improvements, the status of the Unit 1 safety injection system, and the root cause analysis program. In addition, SCE provided an update on the ongoing design basis documentation (DBD) review. A copy of the slides used during the licensee's presentations is enclose The meeting convened at 8:30. Introduction Mr. Martin opened by stating that the purpose of the meeting was to continue dialogue between both parties and provide a forum for discussion
of current items of interest. He requested that piping erosion and corrosion be discussed first, followed by remaining items on the agend Mr. Ray introduced his staff, and said that Mr. Short would speak about erosion and corrosion at SONG. Discussion of Erosion and Corrosion Mr. Short gave an overview of the erosion and corrosion program. He then outlined the criteria used to select piping systems for inspection based upon industry guidelines. He said that the NRC reviewed their program in August of 1988, with no major concerns identified at that time. The summary of NRC findings was published in a NUREG. The first round of inspections conducted by SCE in 1988 revealed minor levels of erosion and corrosion. A second round of inspections, conducted in 1989 and 1990, revealed moderate levels of erosion and corrosio Mr. Short stated that the codes being used are reasonably good at predicting general wall thinning, but are less effective in predicting local thinning which results from geometrical configurations. He noted that they have observed unexpected damage in piping downstream from expanders, and in main feedwater bypass line Mr. Martin expressed concern that available industry guidance on identification of systems or piping components susceptible to damage might be insufficient. He cited problems other utilities have had as a reason to quickly increase their understanding of the phenomena involved in erosion and corrosion of piping systems. He stated that the licensee may need to consider performing additional examinations beyond those selected by the progra Mr. Zimmerman asked whether there were any safety hazards associated with restart of Unit 2 while they were still assessing the feedwater bypass line wall thinning at Unit 3. Mr. Ray responded that they took necessary precautions to preclude safety hazards related to the piping systems in questio Mr. Martin noted that the wall thinning issue is an area of limited knowledge, based principally on empirical industry experience. He said the discussion so far had been dominated by what is not known. For this reason, he said it would be prudent for SCE to increase their efforts on the investigatio Mr. Ray stated that he agreed. He said they realize the need to reassess their program because they do not have full confidence in the current methodology. He noted that he was concerned with localized phenomena, such as that experienced in the startup feedwater bypass line Mr. Zimmerman asked whether industry was developing any new methods to predict erosion and corrosion. In response, Mr. Ray stated that nothing new has come up yet; SCE is developing its own progra Mr. Martin stated that immediate results might be realized if they evalu ated other systems in the plant which have similar configurations. He also said that industry could benefit from SCE's experience through the publication of a technical summary document. Mr. Ray agreed, and said they would issue an informational Licensee Event Repor Mr. Zimmerman stated his concerns about lessons learned from operating experience. He asked whether SCE was sharing information with industr Mr. Ray stated that SCE was a member of a users' group that shares information on erosion and corrosio Mr. Martin stressed the importance of carefully assessing the wall thinning issue, because it could lead to significant consequence. Single Failure Analysis Mr. Merlo discussed SCE's progress on the single failure analysis validation for Unit 1, as discussed in Unit 1 LER 90-16 and the refer enced lette He stated that SCE has high confidence in the analysis conducted, which revealed several potential single failure scenarios involving low-probability events. All but one of these will be resolved before restart from the current outage. One modification will be deferred to the cycle 12 refueling outage due to procurement delays, but the related issue has been addressed procedurall Mr. Caldwell asked whether the selection criteria had been expanded beyond loss of coolant accidents. Mr. Merlo replied that the single failure analysis now considers all events in Chapter 15 of the UFSA Mr. Martin asked whether an independent audit on the single failure analysis would reveal any problems. Mr. Merlo replied that SCE had done a comprehensive analysi. Environmental Qualification Validation Program Mr. Merlo discussed the status of the revalidation of-their environ mental qualification program. A minimum number of deficiencies were identified, and no programmatic problems were evident. The targeted completion date for Unit 1 is the end of 1990 to complete the remaining system walkdowns. Complete reverification of the Units 2 and 3 environ mental qualification program is scheduled for cycle si Mr. Martin questioned the completeness of efforts put toward the validation. Mr. Merlo stated, in response, that the environmental qualification program for Unit 1 has never been bette. Safety Injection System Mr. Rosenblum gave an update on the status of the Unit 1 safety injection system. He said the analysis of the emergency core cooling systems (ECCS) was done by SCE's own staff. He noted that they revalidated the hydraulic calculations, revalidated the inservice testing program, and improved the vendor interface. Problems found were categorized into modeling problem Mr. Martin commented that doing their own analysis should cause the engineering department to become and remain more familiar with the systems in Unit. Root Cause Analysis Program Mr. Katz discussed the recently established root cause group. The group's objectives are to evaluate industry experiences for applicabi lity to SONGS, and to maintain overall responsibility for the root cause analysis progra. Design Basis Documentation Update Mr. Curran gave an overview of the status of the design basis documen tation (DBD) reconstitution efforts to date, plus future plan Mr. Martin asked SCE how they would characterize the form the effort is taking. Mr. Ray responded that SCE is a member of NUMARC, and that NUMARC has published guidelines. Mr. Martin questioned the adequacy of these guidelines. Mr. Ray stated in response that his concerns involved the rigor of the methods used from system to system. He noted the need to apply the same standards to all system Mr. Martin emphasized that system and design engineers, as part of the DBD effort, need to verify the field equipment against documentatio. Closing Remarks Mr. Tatum commented on the recent management changes. He expressed hope that the several changes recently made would not adversely affect recent gains in performanc Mr. Martin thanked those present for their participation, and adjourned the meeting at 11:30 SANC~bG~rj~
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Single Failure Analysis Background 1976 ECCS Analysis PT-459 Failure (1986)
U1C10 Restart Report (1989)
Single Failure Analysis Scope ECCS Systems ECCS Support Systems
Single Failure Analysis Critei
ANSI N658-1976
Single Failure Analysis Methodology SCE Personnel Boundary Valve Analysis FMEA of ECCS Systems/Devices Time & Event Specific Analysis
Single Failure Analysis Status Over 3,000 Interactions Evaluated 10 Modifications in Cycle 11 Assumption Validation One Modification in Cycle 12
Vital Bus Retransfer Train DC Bus #1 B
A
~~*A uv Switch
/2 PB 3A Dus
X Fuse Fuse
Single Failure Analysis Conclusion High Confidence in Unit 1 SFA Compliance 10 of 11 Modifications Completed for Restart Vital Bus Transfer Deferred to U1C12
EQ Background Indicators Foxboro Configurations (LER 89-012)
U1C10 Engineering Quality Program QA Audits
EQ Validation Plan
Walkdowns.- Baseline Plants
EQDP's Match Plant
EQDP's Match Analysis
Programs Insure Configuration
Pindings Pressurizer Pressure Transmitter Containment Sump Level Transmitter Raychem Splices SDC Suction Isolation Valves
EQ Conclusion Minimum Number of Field Problems Identified No Programmatic Problems Found All Equipment Discrepancies Resolved Prior to Restart U1 Plant & Documentation Baselined Programs Enhanced to Maintain Configuration
SAFETY INJECTION SYSTEM
.
Recent Experience
.
Restart Status
SAFETY INJECTION SYSTEM Recent Experience Programatic Issues
- Environmental Qualification (EQ)
- Single Failures
- Safety System Modeling-Technical Specifications Random Equipment Failures
SAFETY INJECTION SYSTEM Restart Status g
EQ Validation Plan
- Extensive Reevaluation will be Complete
.
Plant Walkdowns
Package Updates No New Programatic Issues Identified
SAFETY INJECTION SYSTEM Restart Status Single Failure Analysis Complete
-
Complete Reanalysis of ECCS
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Current Design Criteria
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State-of-the-Art Methodology
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Internal Experienced Engineering Staff
SAFETY INJECTION SYSTEM Restart Status Safety System Modeling
-
New Hydraulic Calculations
-
ECCS Delays Updated
-
IST Changes
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Modifications Vendor Interface Improved
SAFETY INJECTION SYSTEM Restart Status Major Technical Specification Revision Submitted
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10 Technical Specifications Submitted
-.Adds Standard Technical Specification LCO's and Action Statements
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Specifically Identifies Train and Flow Path Alignment Operability Requirements
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Eliminates Unnecessary 3.0.3 Entry
NUCLEAR OVERSIGHT DIVISION SAFETY ENGINEERING ACTIVITIES
NUCLEAR OVERSIGHT DIVISION Quality Supplier Quality Performance SAFETY Assurance Quality Control Assessment ENGINEERING Assessment Nuclear
-
Safety Group Quality Engineering Hiuman I A
Performance Coordinator ISEG/Root Cause Group
ISEG/ROOT CAUSE GROUP o Evaluate Industry Experiences for applicability to SONGS (SERs, SOERs, NRC Bulletins, Information Notices, Vendor Bulletins)
o Overall responsibility for Root Cause Program
ROOT CAUSE PROGRAM o October 27, 1989 Letter to NRC commits to central program o Safety Engineering established January 1. 1990
- Directive, Procedures, Staffing, Training completed June 30, 1990 o Root Cause Program Scope
- Safety Engineering Root Cause Investigations
- Nonconformance Reports
- Licensee Event Reports
- Division Incident Reports
- Human Performance Evaluations o Future Program Plans
- Develop Single Nuclear Department Procedure to cover all division investigations and root cause determinations
- Expand training in root cause technique throughout Nuclear Organization
I0 The upgrading of the technical resource within NOD has significantly improved our capability to actively and independently pursue safety issues and other activities where improved performance is desire Design Bases Documentation (DBD)
Overview
- Concentrated on Program, Procedures and Data Retrieval
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Complies - NUMARC Design Bases Program Guidelines
- Invested in Relational Data Bases - Multiple Benefit
- Allowed for Systematic Production of DBDs
- Validation Effort
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Interdiscipline Reviews
-
Vertical Assessment
Design Bases Documentation (DBD)
DBD Status And Overview DBD Schedule
Fifteen (15) DBDs are in Active Preparation
-
Twelve (12) Unit 1 and Three (3) Units 2&3
Six (6) Unit 1 DBDs are Targeted for Completion in 1990 Forecast Total All Years 1990 1991 1992-1995 Unit 1 DBDs
6
27 Unit 2&3 DBDs
0
39 TOTAL DBDs
6
66
Design Bases Documentation (DBD)
DBD Status And Overview Open Item Reports (OIRs)
Issued Description
% Total Ns NCRs Nonconforming OIRs
6 Bases discrepancy
Bases unavailable
Doc discrepancy
Doc unobtainable
-
DBD Expenditures ($ in millions)
Forecast Pre - 1990 1990 1991 1992-1995 TOTAL Unit 1
$ $ $ $ $1 Unit 2.1.5 Unit 3.1.5 TOTAL
$ $ $ $1 $32.3