ML14138A124
| ML14138A124 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/07/1983 |
| From: | Paulson W Office of Nuclear Reactor Regulation |
| To: | Dietch R Southern California Edison Co |
| References | |
| TASK-05-05, TASK-5-5, TASK-RR LSO5-83-03-010, LSO5-83-3-10, NUDOCS 8303100361 | |
| Download: ML14138A124 (7) | |
Text
March 7, 1983 Docket-No. 50-206 LS05-83-03=010 Mr. R. Dietch, Vice President Nuclear Engineering and Operations Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800,
Rosemead, California 91770
Dear Mr. Dietch:
SUBJECT:
SEP TOPIC V-5, REACTOR COOLANT PRESSURE BOUNDARY LEAKAGE DETECTION - SAN ONOFRE NUCLEAR GENERATING STATION, UNIT 1 By letter dated June 3, 1981, the staff issued a draft safety evaluation of Topic V-5 for the San Onofre Nuclear Generating Station, Unit 1. Your letter of January 20, 1983, provided comments on the factual correctness of the basis of the staff's evaluation. As a result of these comments, the staff has prepared the enclosed final topic safety evaluation. As noted in this-evaluation, the staff could not conclude that the leakage detection systems are in conformance with Regulatory Guide 1.45. The need for plant modifications will be determined during the integrated assessment.
This evaluation will be a basic input to the integrated safety assessment for your facility unless you identify changes needed to reflect the as-built conditions at your facility. This assessment may be revised in the future if your facility design is changed or if NRC criteria relating to this subject are modified before the integrated assessment is completed.
Sincerely, Original Signed bys Walter A. Paulson, Project Manager Operating Reactors Branch No. 5 Division of Licensing
Enclosure:
As stated cc w/enclosure:
See next page 8303100361 830307 PDR ADOCK 05000206 P
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/83 NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
Mr. R. Dietch, Vice Prewent Docket No. 50-206 Nuclear Engineering and uperations San Onofre 1 Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800 Rosemead, California 91770 cc Charles R. Kocher, Assistant General Counsel James Beoletto, Esquire Southern California Edison Company Post Office Box 800 Rosemead, California 91770 David R. Pigott Orrick, Herrington & Sutcliffe 600 Montgomery Street
- San Francisco, California 94111 Harry B. Stoehr San Diego Gas & Electric Company Post Office Box 1831 San Diego, California 92112 Resident Inspector/ San Onofre NPS c/o U.S. Nuclear Regulatory Commission Post Office Box 4329 San Clemente, California 92672.
Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 California Department of Health ATTN: Chief, Environmental Radiation Control Unit Radiological Health Section 714 P Street, Room 498 Sacramento, California 95814 U.S. Environmental Protection Agency Region IX Office ATTN: Regional Radiation Representative 215 Freemont Street San Francisco, California 94111 Robert H. Engelken, Regional Administrator U.S. Nuclear Regulatory Commission, Region V 1450 Maria Lane Walnut Creek, California 94596
SYSTEMATIC EVALUATION PROGRAM TOPIC V-5 SAN ONOFRE NUCLEAR GENERATING STATION, :UNIT 1 TOPIC:
V-5, Reactor Coolant Pressure Boundary (RCPB) Leakage Detection I.
INTRODUCTION The safety objective of Topic V-5 is to determine thereliability and sensitivity of the leak detection systems which monitor the reactor coolant pressure boundary to identify primary system leaks at an early stage before failures occur.
II. REVIEW CRITERIA The acceptance criteria for the detection of leakage from the reactor coolant pressure boundary is stated in the General Design Criteria of Appendix A, 10 CFR Part 50, Criterion 30, "Quality of Reactor Co6lant Pressure Boundary," requires that means shall be provided for detecting and, to the extent practical, identifying the location of the source of leakage in the reactor coolant pressure boundary.
III. RELATED TOPICS III-5.A, Effects of Pipe Break Inside Containment V-10.A, RHR Tube Failures IV. REVIEW GUIDELINES The acceptance criteria are described iA Standard Review Plan Section 5.2.5, "Reactor Coolant Pressure Boundary Leakage Detection."
Regulatory Guide 1.45, "Reactor Coolant Pressure Boundary Leakage Detection Systems," describes methods acceptable to the staff for implementing the requirement to detect RCPB leakage.
V.
EVALUATION Safety Topic V-5 was evaluated in this review for compliance of the information submitted by the licensee with Regulatory Guide 1.45, "Reactor Coolant Pressure Boundary Leakage Detection Systems." The information in the Safety Analysis Report, Technical Specifications, the March 5, 1979 letter from SCE to the NRC regarding SEP Topic V-10.A, the April 8, 1981 letter from SCE to the NRC regarding SEP Topic V-5, and the January 20, 1983 letter from SCE to the NRC for San Onofre Unit 1 was reviewed. Regulatory Guide 1.45 requires that at least three separate detection systems be installed in a nuclear power plant to detect an unidentified leakage from the reactor coolant pressure boundary
-2 to the primary containment of one gallon per minute within one hour.
Leakage from identified sources must be isolated so that the flow rates may be monitored separately from unidentified leakage. The detection systems should be capable of performing their functions following certain seismic events and capable of being checked in the control room. Of the three separate leak detection methods required, two of the methods should be (1) sump level and flow monitoring and (2) airborne particulate radioactivity monitoring. The third method may be either monitoring of condensate flow rate from air coolers or monitoring of airborne gaseous radioactivity. Other detection methods such as humidity, temperature and pressure, should be considered to be alarms of indirect indication of leakage to the containment. In addition, provisions should be made to monitor systems interfacing with the reactor coolant pressure boundary for signs of intersystem leakage through methods such as radioactivity and water level or flow monitors.
Plant incorporated systems and their corresponding features are tabulated in Enclosure 1. Detailed guidance for the leakage detection system is contained in Regulatory Guide 1.45.
Based upon our review of the referenced documents and the summaries presented in Enclosure 1, we have determined:
- 1) The systems employed for the detection of leakage from the reactor coolant pressure boundary to the containment consist of the minimum three required by Regulatory Guide 1.45 plus additional systems.
However, the sensitivities of the leak detection systems have not been verified. The licensee is conducting a study to determine system sensitivities and the time needed to achieve them.
- 2) Provisions are made to monitor reactor coolant in-leakage to those systems listed in Table 2 of Enclosyre 1. Information concerning the leak detection methods, similar to that given for the detection systems in Table 1 of Enclosure 1, is incomplete for those in Table 2, and should be provided.
- 3) The San'Onofre 1 Technical Specifications do not impose requirements concerning the operability of the leakage detection systems to monitor leakage to the primary containment, as required by Regulatory Guide 1.45. The Technical Specification limiting condition for operation (LCO) on unidentified leakage is 1 gpm. However, no time frame for detection is specified. The results of the sensitivity study should be used to establish the appropriate time (RG 1.45 recommends 1 gpm
-in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />).
-3
- 4) None of the systems have been demonstrated to remain functional following a safe shutdown earthquake (SSE). The licensee stated in its January 20, 1983 letter, that seismic capability would be reviewed when USI A-46 is finalized.
- 5) Not all of the leakage detection systems have provisions for testing operability and calibration during plant operation.
VI.
CONCLUSION Based on our review, we have concluded that the systems provided for monitoring leakage from the RCPB do not conform with the recommendations of Regulatory Guide 1.45 in several areas (see above). The licensee is presently evaluating the sensitivity of these systems. The results of that study will be used during the integrated plant safety assessment to.determine the need for plant modifications.
Enclosure I REACTOR COOLANT PRESSURE BOUNDARY LEAKAGE DETECTION SYSTEMS Requlatory Guide 1.45 Regutrement5 Table 1:
Plant: San Onofre Unit 1 RCPB to Containment Time Required Earthquake For Control Room Testable Leak Rate To Achieve Which Function Indication For During Normal System Incor orated Sensitivity Sensitivity Is Assured Alarms & Indicators Operation Yes (as part of 1). Sunp Level Monitoring NUREG-0737, TBD TBD TBD YES NO (Inventory)
II.E.1(5)
Monitoring entries
- 5) Condensated Flow Rate NO from Air Coolers
- 8)
Containment Atmosphere YES TBD TBD TBD YES NO Temperature Monitoring
- 9) Accoustic Emissions NO
- 0) Moisture Sensitive Tape NO
To Be Determined
- Monitored By Administrative Procedures
REACTOR COOLANT PRESSURE BOUNDARY LEAKAGE DETECTION-SYSTEMS Regulatory Guide 1.45 Requirements labl1 2
Plant:
San Onofre Unit 1 Intersystem Leakage Methods to Leak Rate Time Required Earthquake For Control Room Testable Measure RCPB Sensitivity To Achieve Which Function Indication For During Normal Systems Which Interface w/RCPB In-Leakage Sensit ivity Is Assured Alarms & Indicators Operation Condenser Air
- 6)
- 7)
B)
TBD:
To Be Determined