ML20058N022
| ML20058N022 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/30/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20058N015 | List: |
| References | |
| NUDOCS 9310070289 | |
| Download: ML20058N022 (5) | |
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WASHINGTON, D.C. 2055pm1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 67 TO FACILITY OPERATING LICENSE NPF-68 AND AMENDMENT NO. 46 TO FACILITY OPERATING LICENSE NPF-81 GEORGIA POWER COMPANY. ET AL.
V0GTLE ELECTRIC GENERATING PLANT. UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425
1.0 INTRODUCTION
By WCAP-13377,Rev 2 & Proprietary WCAP-13376,Rev 2, Bypass Test Instrumentation for Vogtle Electric..., encl.WCAP-13376,Rev 2 Withheld|letter dated March 1,1993]], as supplemented July 26 and August 27, 1993,*
Georgia Power Company, et al. (the licensee) proposed license amendments to change the Technical Specifications (TS) for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2.
The proposed changes would revise TS 3/4.3.1,
" Reactor Trip System Instrumentation," TS 3/4.3.2, " Engineered Safety Feature Actuation System Instrumentation," and their associated TS Bases. These changes would relax surveillance test intervals (STI) and allowed outage times (A0T) for engineered safety features actuation system (ESFAS) instrumentation based on Westinghouse Topical Report WCAP-10271, Supplement 2, Revision 1,
" Evaluation of the Surveillance Frequencies and the Out of Service Times for the Reactor Protection Instrumentation System." The changes to TS 3/4.3.1 for the reactor trip system (RTS) are those directly associated with implementing the ESFAS relaxations as recommended by the NRC staff in previous safety evaluation reports (SER) regarding WCAP-10271. The licensee also submitted Westinghouse Topical Report (WCAP) 13376, Revision 2, " Bypass Test Instrumentation For The Vogtle Electric Generating Plant Units 1 & 2" (prnprietary version), and WCAP 13377, same title, Revision 2, (non-proprietary version) in support of the bypass test instrumentation (BTI).
WCAPs 13376 and 13377 discuss conformance of the BTI to the applicable General Design Criteria, Regulatory Guides, and IEEE Standards. The August 27, 1993, letter corrected the hand-marked depiction of the proposed change to agree with the changes as described by the NRC in the Federal Reaister (58 FR 42350) on August 9, 1993. Therefore, this correction did not change the NRC's proposed finding of no significant hazards consideration determination.
The licensee is making plant hardware and procedural modifications to perform routine testing in bypass of the ESFAS and RTS instrumentation without the use-of temporary jumpers or the lifting of leads. Therefore, the licensee proposes certain changes to the Vogtle TS to incorporate the provisions of l
" test in bypass."
1 9310070289 930930 PDR ADOCK 05000424 1
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- The changes to TS 3/4.3.1 would include:
(1)
Retaining the current Action Statement 6 as Action Statement 9 for reactor coolant pump undervoltage and underfrequency trip functions because this instrumentation is excluded from " tested in bypass".
(2)
Revising Action Statements 2 and 6 to allow for " test in bypass."
(3) Adding table notation f to identify all instrument functional units which have " test in bypass" capability.
(4) Deleting notation 17 and its associated reference that required the performance of a RTS analog channel operational test on a staggered basis.
(5) Deleting notations g and 18 and appropriate references in TS Table 3.3-1 and Table 4.3-1 that indicate that ESFAS actions are more restrictive, and therefore, are applicable.
(6) Adding Action Statement 7 to allow 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to restore an inoperable channel to operable status before requiring shutdown to Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Also, allowing one channel to be bypassed up to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for surveillance testing, provided the other channel is operable.
The changes to TS 3/4.3.2 would include:
(1) Revising Action Statement 20 to allow for " test in bypass."
(2) Adding table notation "##" to identify those instrumentation functional units that have " test in bypass" capability.
(3)
Changing functional Units 1.c, 1.d, 1.e, 2.c, 4.c, 4.d, 4.e, 5.c, f
6.b, 6.d, and 9.a to increase the STI for analog channel operational tests from monthly to quarterly.
(4)
Revising Action Statement 20 and adding new Action Statement 29 to increase, from I hour to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, the time that an inoperable ESFAS channel may be maintained in an untripped condition.
(5) Deleting current Action Statement 15. Assigning the functional units which used current Action Statement 15 to other Action Statements.
(6)
Revising Action Statements 14, 17, 20, 22, and 25 to increase, from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, the time that an inoperable ESFAS channel may be bypassed to allow testing of another channel for the same function.
(7)
Adding new Action Statements 15 and 29 since the A0T for the applicable functional units will remain at 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for an additional channel that is bypassed during surveillance testing.
- (8)
Revising Action Statements 14, 22, and 25 to allow 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to restore an inoperable channel to operable status before requiring shutdown to Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
(9) Adding Action Statement 29 to allow startup and power operation to proceed when the number of operable channels is one less than the total number of channels, provided certain conditions are met.
(10) Deleting notation d and appropriate references to establish consistency with previous amendments on Vogtle regarding Generic letter 87-09, " Sections 3.0 and 4.0 of The Standard Technical Specifications (STS) on the Applicability of Limiting Conditions for.
Operation and Surveillance Requirements."
(11) Increasing, administratively, each Action Statement number 29 and higher in TS Tables 3.3-4 and 3.3-8 so that each Action Statement would continue to be unique.
(12) Revising the Bases for TS 3/4.3.1 and 3/4.3.2 to include editorial changes and a reference to the NRC staff's SER on WCAP-10271, Supplement 2, Revision 1.
j 2.0 EVALUATION The licensee is modifying the plant to allow the surveillance testing of certain ESFAS and RPS channels in bypass without using temporary jumpers or lifting leads. This modification will allow the licensee to test or maintain a channel without placing it in a tripped condition.
Presently, with one channel tripped, a redundant channel cannot be maintained or tested without risking a spurious reactor trip or engineered safety features actuation.
After the modification, with the bypass test instrumentation (BTI) installed, the spurious reactor trip or engineered safety features actuation will be avoided because the partial trip condition is eliminated and the coincident logic is maintained, requiring signals from two other channels in order to initiate a protective action.
The licensee has submitted Westinghouse Topical Report (WCAP) 13376, Revision 2, " Bypass Test Instrumentation For The Vogtle Electric Generating Plant Units 1 & 2" (proprietary version), and WCAP 13377, same title, Revision 2, (non-proprietary version) in support of the BTI.
The licensee has elected not to implement the BTI for the reactor coolant pump undervoltage and underfrequency trip functions; the NRC staff has not reviewed the topical report for these functions.
i WCAPs 13376 and 13377 discuss conformance of the BTI to the applicable General Design Criteria, Regulatory Guides, and IEEE Standards.
A limiting single failure could exist if a channel should fail to come out of bypass while indicating that it has returned to normal.
In this event, subsequently bypassing another channel could cause two channels to be simultaneously in bypass.
This condition, in a two-of-three logic, could prevent a reactor trip from being generated when needed.
For this failure to occur, one contact in the low voltage relay associated with the key-lock switch would have to be
- stuck closed. The expected occurrence of this failure mode is low based on the voltage requirements of the system. Also, this condition would be detected by the TS channel calibration because the calibration could not be performed in its entirety with the channel in bypass.
Because the channel calibration is required by TS and any such failure would be detected during the calibration, the NRC staff finds this potential type of failure to be acceptable.
After the modification, each protection channel will have its own associated BTI panel. The non-class lE part of the BTI will be isolated from class IE circuits by qualified isolators. Thus, no credible control system fault will be able to propagate to all the bypass panels and simultaneously adversely affect all protection channels.
BTI panels for the Nuclear Instrumentation System will contain both safety and non-safety 118 Vac circuits; separation will be maintained by a ground layer placed between these circuits. No other
^
BTI panels will require separation because they contain either all safety or all non-safety circuits. The BTI panels and all the components of the BTI.are seismically qualified for the Vogtle site and environmentally qualified for Vogtle plant conditions. The licensee has evaluated all BTI panels for seismic qualification with respect to the effect on the instrument rack where they will be installed. This licensee evaluation determined that the instrumentation rack would maintain its structural integrity and electrical isolation capability.
The BTI system will have several administrative controls.
It can only be enabled by a key-lock switch. When a channel is bypassed, it will be annunciated in the control room. An individual signal in a channel can be bypassed by a toggle switch, causing a bypass indication light for that signal i
to be displayed on the BTI panel. Administrative controls will also ensure that if a channel fails during surveillance testing, it will be placed in a tripped condition. The NRC staff finds that sufficient administrative r
controls are provided for the safe operation of the BTI system.
Based on the above evaluation, the NRC staff concludes that the BTI meets NRC 4
requirements and can be safely and effectively used to reduce the potential of spurious actuation of the Vogtle RTS and ESFAS.
The NRC staff has previously reviewed WCAP-10271 and issued SERs on February 22, 1989, and April 30, 1990, approving its proposed changes subject to certain conditions. The licensee has responded to these conditions in a manner that demonstrates the changes proposed for Vogtle are bounded by the topical report analysis. Based on the SERs and the licensee's response to the conditions of the SERs, the NRC staff finds the proposed changes to TS 3/4.3.1 and TS 3/4.3.2 to be acceptable.
Additionally, three changes, identified in the Introduction to this SER as items (10), (11), and (12) under changes to TS 3/4.3.2, are either editorial or administrative in nature. The NRC staff finds that these three changes have no adverse safety impact and are, therefore, acceptable.
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3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Georgia State official was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change requirements with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR-Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (58 FR 42350 dated August 9,1993).
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: Darl Hood Douglas Starkey Hukam Garg Date:
September 30, 1993 i
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