05000250/FIN-2015007-02
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Finding | |
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| Title | Potential Departure From the Eagle 21 Design Basis |
| Description | The inspectors identified an Unresolved Item (URI) regarding the licensees compliance with TS and the design bases for the Eagle 21 digital reactor protection system. The inspectors reviewed the licensees 10 CFR 50.59 screening associated with the Eagle 21 modifications for the Thermal Over-Power (OPT), Thermal Over- Temperature (OTT) trip functions, and the Main Steam Pressure Lead/Lag module. These were documented in engineering change packages 246973 for Unit 3 and 246974 for Unit 4. The Eagle 21 was the computerized portion of the reactor protection system. The inspectors noted that WCAP-12374, Topical Report Eagle-21 Microprocessor- Based Process Protection System, specified design bases compliance with the following: - IEEE 279-1971, Criteria for Nuclear Power Plant Protection Systems, - IEEE 603-1980, "IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations," - RG 1.153-1985, "Criteria for Power, Instrumentation, and Control Portions of Safety Systems," - IEEE 7-4.3.2-1982, "Application Criteria for Programmable Digital Computer Systems In Safety Systems of Nuclear Power Generating Stations," and - RG 1.152-1985, "Criteria for Programmable Digital Computer System Software in Safety-Related Systems in Nuclear Plants." Following the extended power uprate (EPU), the licensee determined that the four computerized surveillance tests established to verify the Eagle 21 performance requirements for the (OP & OT) T trips would not pass. The inspectors determined that the licensee changed their procedures to set certain variables to zero in the Eagle 21 computer programs transfer function before performing the surveillance tests. After completing the tests, the licensee re-programmed the zeroed variables to their correct values (the post EPU configurations) before returning the Eagle 21 to service. The inspectors determined that the surveillance tests no longer demonstrated the adequacy of the (OP & OT) T performance requirements or the Eagle 21 final outputs. Because of the inspectors questions, the licensee reevaluated the surveillance testing requirements and captured this issue in AR 2023314, Potential Missed Surveillance on CHs 1, 2 and 3 of Eagle 21. The licensees reevaluation determined that at least one of the tests, the dynamic function surveillance test, could have been performed with the post EPU configuration. In the ARs prompt operability determination, the licensee determined that the surveillance testing changes did not affect plant operability. The inspectors determined that the Eagle 21 design bases required field changes to follow specific design control measures for safety system criteria and computer system requirements including software development, hardware-software integration, computer system validation, and verification. The inspectors could not verify that the licensees Eagle 21 modifications met the specified design bases for the protective functions. The inspectors determined that the licensees failure to perform appropriate surveillance testing of the (OP & OT) T performance requirements as determined by TS was a performance deficiency. The inspectors opened URI 05000250, 251/2015007-02 to determine if the associated performance deficiency is more than minor. To resolve this URI, the inspectors needs to determine if the design and verification processes used for the modifications met the Eagle 21 design bases requirements in accordance with 10 CFR 50, Appendix B Criterion III. In addition, the inspectors needs to verify the following six items: - that the as installed (OP & OT) T Eagle 21 configurations were field verified against the design basis from the Updated Final Safety Analysis Report (UFSAR) and TS, in accordance with 10 CFR 50.55a(h)(2), and 10 CFR 50, Appendix B Criterion III, - that the availability and adequacy of Eagle 21 design bases information was consistent with 10 CFR 50.34(b) and 10 CFR 50.71(e), - that the Eagle 21 design bases were evaluated in accordance 10 CFR 50.59(c)(2)(i) & (ii), - the applicability of the licensees commitment to the designed Eagle 21 (OP & OT) T surveillance testing requirements, trip time response testing, - that the licensee identified the causes for the failures in the surveillance equipment, and that the licensee can calibrate the equipment to perform the four surveillance tests with post EPU configurations installed in accordance 10 CFR 50, Appendix B Criterion XII, and - the adequacy of the licensee oversight of Eagle 21 vendor modifications in accordance with 10 CFR 50, Appendix B Criterion VII. |
| Site: | Turkey Point  |
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| Report | IR 05000250/2015007 Section 1R17 |
| Date counted | Mar 31, 2015 (2015Q1) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.17 |
| Inspectors (proximate) | E Stamm J Bartley N Coovert T Fanellia Senguptaj Patel J Rivera L Suggs R Reyes R Williams T Fanelli T Hoeg W Loo |
| INPO aspect | |
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Finding - Turkey Point - IR 05000250/2015007 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Turkey Point) @ 2015Q1
Self-Identified List (Turkey Point)
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