UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, DC 20555-0001 April 28, 1995 |
NRC GENERIC LETTER 95-04: | FINAL DISPOSITION OF THE SYSTEMATIC EVALUATION PROGRAM LESSONS-LEARNED ISSUES |
Addressees All holders of operating licenses or construction permits for nuclear power reactors. Purpose The U.S. Nuclear Regulatory Commission (NRC) is issuing this generic letter to notify addressees about the final disposition of the 27 lessons-learned issues found in the Systematic Evaluation Program (SEP). It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate. However, suggestions contained in this generic letter are not NRC requirements; therefore, no specific action or written response is required. Background In 1977, the NRC staff initiated the SEP to review the designs of older operating nuclear power plants, i.e., plants licensed before 1975 when the Standard Review Plan (SRP) (Reference 1) was issued. In Phase I, the NRC staff identified 137 issues for which the regulatory requirements had changed, and which warranted an evaluation. In Phase II, the NRC staff compared the designs of 10 SEP plants to the SRP issued in 1975. The NRC staff found that 27 of the original 137 issues required some corrective action at one or more of the 10 plants examined in the SEP. The NRC staff also concluded that corrective actions for these 27 issues could benefit safety at older operating plants not in the group of 10 plants examined in the SEP (non-SEP plants). Therefore, the NRC staff concluded that these 27 issues should be considered at the non-SEP plants to determine whether an adequate level of safety existed at these plants. Discussion To determine what actions might be appropriate for the non-SEP plants, the NRC staff determined whether each SEP issue had been resolved by a particular licensee, needed to be resolved, or was addressed by other regulatory programs and activities, and placed the SEP issues in four categories. This information was sent to the Commission in SECY-90-343, dated October 4, 1990 (Reference 2), as follows: |
(1) | Completely resolved (4) |
(2) | Low safety significance requiring no further regulatory action (1) |
(3) | Unresolved but covered by existing regulatory programs (19) |
(4) | Unresolved; existing regulatory program has not yet been identified (3) |
Further evaluation by the NRC staff as part of the generic safety issues program (NUREG-0933, "A Prioritization of Generic Safety Issues," Reference 3) led to some adjustments among the categories after SECY-90-343 was issued. The final categorizations follow: |
(1) | Completely resolved (4) |
(2) | Low safety significance requiring no further regulatory action (2) |
(3) | Unresolved but covered by existing regulatory programs (20) |
(4) | Unresolved; existing regulatory program has not yet been identified (1) |
Attachment 1 lists the six issues in categories 1 and 2. The NRC staff determined that the 21 issues remaining in categories 3 and 4 did not require immediate action to protect public health and safety, and incorporated them into the established NRC regulatory process for determining the safety importance of generic safety issues. The 20 issues in category 3 are covered by existing regulatory programs described in NUREG-0933. The NRC staff has incorporated the category 4 issue into the generic issues program and is determining the priority of this category 4 issue, SEP Issue 6.1, "Pipe Break Effects on Systems and Components" (now New Generic Issue 156.6.1 in Reference 3). Attachment 2 lists the 21 issues in Categories 3 and 4. The NRC staff will no longer track SEP issues separately because each original SEP issue is either resolved, need not be resolved, or has been incorporated into the generic issues program. The pipe break issue is currently being assigned a priority under the generic issues program. Consequently, future consideration of the original SEP issues will be confined to the normal reviews, audits, or inspections carried out in conjunction with the generic issues program. The staff procedure for handling generic issues involves evaluating any proposed actions for each case under existing regulations and procedures and considering backfit implications in accordance with Section 50.109 of Title 10 of the Code of Federal Regulations (10 CFR 50.109). This generic letter requires no specific action or written response. If you have any questions about this matter, please contact the technical contact listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager. |
| | | | | orig /s/'d by RPZimmerman Roy P. Zimmerman Associate Director for Projects Office of Nuclear Reactor Regulation |
Technical contact: | Sheri R. Peterson, NRR (301) 415-2752 |
References: |
1. | NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants," 1st Edition, November 1975. |
2. | SECY-90-343, "Status of the Staff Program to Determine How the Lessons Learned From the Systematic Evaluation Program Have Been Factored Into the Licensing Bases of Operating Plants," October 4, 1990. |
3. | NUREG-0933, "A Prioritization of Generic Safety Issues," Supplement 17, September 1994. |
Attachments: |
1. | SEP Issues in Categories 1 and 2 |
2. | SEP Issues in Categories 3 and 4 |
3. | List of Recently Issued NRC Generic Letters. |
Attachment 1 |
SEP ISSUES IN CATEGORIES 1 AND 2 | SEP ISSUE NUMBER | TITLE | REFERENCE | CATEGORY | 3.6.2 | Emergency DC Power | 3 | 2 | 3.7 | Leakage Detection at the Reactor Coolant Pressure Boundary | 2 | 1 | 5.1 | Organic Materials | 2 | 1 | 5.2 | Water Purity in the Reactor Coolant System | 2 | 1 | 6.2 | Containment Isolation | 2 | 1 | 6.3 | Reactor Coolant System Activity Limits | 2 | 2 | Category 1 - Completely resolved Category 2 - Low safety significance requiring no further regulatory action |
Attachment 2 |
SEP ISSUES IN CATEGORIES 3 AND 4 | SEP ISSUE NUMBER | TITLE OF ISSUE | EXISTING REGULATORY PROGRAM RESOLVING SEP ISSUE (see Notes) | CATEGORY | 1.1 | Settlement of Foundations and Buried Equipment | IPEEE | 3 | 1.2 | Dam Integrity and Site Flooding | IPEEE | 3 | 1.3 | Site Hydrology and Ability to Withstand Floods | IPE, IPEEE | 3 | 1.4 | Industrial Hazards | IPEEE | 3 | 1.5 | Tornado Missiles | IPEEE | 3 | 1.6 | Turbine Missiles | TAP A-37 | 3 | 2.1 | Severe Weather Effects on Structures | IPEEE | 3 | 2.2 | Design Codes, Criteria, and Load Combinations | IPEEE | 3 | 2.3 | Containment Design and Inspection | NGI 118 | 3 | 2.4 | Seismic Design of Structures, Systems, and Components | IPEEE | 3 | 3.1.1 | Shutdown Systems | TAP A-45, IPE, IPEEE, SDLOW | 3 | 3.1.2 | Electrical Instrumentation and Controls | TAP A-45, IPE, IPEEE, SDLOW | 3 | Category 3 - Unresolved but covered by existing regulatory programs Category 4 - Unresolved; no covering existing regulatory program yet identified SEP ISSUES IN CATEGORIES 3 AND 4 | SEP ISSUE NUMBER | TITLE OF ISSUE | EXISTING REGULATORY PROGRAM RESOLVING SEP ISSUE (see Notes) | CATEGORY | 3.2 | Service and Cooling Water Systems | NGI 51, 130, 143, 153; GL 89-13, 91-13; TAP SW | 3 | 3.3 | Ventilation Systems | NGI 83, 106, 136, 143, 148; 10 CFR | 3 | 3.4 | Isolation of High and Low Pressure Systems | NGI 105 | 3 | 3.5 | Automatic Emergency Core Cooling System (ECCS) Switchover | NGI 24 | 3 | 3.6.1 | Emergency AC Power | TAP A-44, B-56; NGI 128 | 3 | 3.8 | Shared Systems | TAP A-44; NGI 43, 130, 153 | 3 | 4.1 | Reactor Protection System (RPS) and Engineered Safety Features System (ESFS) Isolation | NGI 142 | 3 | 4.2 | Testing of the RPS and ESFS | NGI 120; 10 CFR | 3 | 6.1 | Pipe Break Effects on Systems and Components | NGI 156.6.1 | 4 | Category 3 - Unresolved but covered by existing regulatory programs Category 4 - Unresolved; no covering existing regulatory program yet identified |
|
NOTES |
Program | Reference |
IPEEE | Generic Letter 88-20, Supplement 4, "Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities - 10 CFR 50.54(f)," June 28, 1991. |
IPE | Generic Letter 88-20, "Individual Plant Examination for Severe Accident Vulnerabilities - 10 CFR 50.54(f)," November 23, 1988; Supplement 1, August 29, 1989; Supplement 2, April 4, 1990; Supplement 3, July 6, 1990. |
TAP | Task Action Plan Items, NUREG-0933, "A Prioritization of Generic Safety Issues," Supplement 17, September 1994, Section 2. |
A-37 | Turbine Missiles |
A-44 | Station Blackout |
A-45 | Shutdown Decay Heat Removal Requirements |
B-56 | Diesel Reliability |
NGI | New Generic Issues, NUREG-0933, "A Prioritization of Generic Safety Issues," Supplement 17, September 1994, Section 3. |
24 | Automatic ECCS [emergency core cooling system] Switchover to Recirculation |
43 | Reliability of Air Systems |
51 | Proposed Requirements for Improving the Reliability of Open Cycle Service Water Systems |
83 | Control Room Habitability |
105 | Interfacing Systems LOCA [loss of coolant accident] at BWRs [boiling water reactors] |
106 | Piping and Use of Highly Combustible Gases in Vital Areas |
118 | Tendon Anchorage Failures |
120 | On-Line Testability of Protection Systems |
128 | Electrical Power Reliability |
130 | Essential Service Water Pump Failures at Multiplant Sites |
136 | Storage and Use of Large Quantities of Cryogenic Combustibles on Site |
142 | Leakage Through Electrical Isolators in Instrumentation Circuits |
143 | Availability of Chilled Water Systems |
148 | Smoke Control and Manual Fire-Fighting Effectiveness |
153 | Loss of Essential Service Water in LWRs [light water reactors] |
156.6.1 | Referred to the Office of Research for prioritization as Generic Issue 156.6.1. |
SDLOW | SECY-91-283, "Evaluation of Shutdown and Low Power Risk Issues," September 9, 1991. |
GL 89-13 | Generic Letter 89-13, "Service Water System Problems Affecting Safety-Related Equipment," July 18, 1989. |
GL 91-13 | Generic Letter 91-13, "Request for Information Related to the Resolution of Generic Issue 130, `Essential Service Water System Failures at Multi-Unit Sites,' Pursuant to 10 CFR 50.54(f)," September 19, 1991. |
TAP SW | Memorandum from A. Thadani for W. Russell, "Task Action Plan for Resolution of Service Water System Problems," June 27, 1991. |
10CFR | Title 10, Code of Federal Regulations, "Energy" |