ML20058A945
| ML20058A945 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 11/19/1993 |
| From: | Mccoy C GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20058A948 | List: |
| References | |
| LCV-0132, LCV-132, NUDOCS 9312010326 | |
| Download: ML20058A945 (6) | |
Text
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k C. K. McCoy Georgia Power November 19, 1993 I
LCV-0132 Docket Nos. 50-424 50-425 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 t
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VOGTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS AUXILIARY FEEDWATER ACTUATION INSTRUMENTATION In accordance with the provisions of 10 CFR 50.90 and 10 CFR 50.59, Georgia Power Company (GPC) hereby proposes to amend the Vogtle Electric Generating Plant (VEGP) l Unit I and Unit 2 Technical Specifications, Appendix A to Operating Licenses hPF-68 and NPF-81.
This amendment modifies the applicable mode for item 6.e of table 3.3-2. Item 6.e requires that engineered safety features actuation system instmmentation for automatically starting the auxiliary feedwater motor driven pumps on the trip of all main feedwater pumps be operable in Mode 2. The modification is in the form of a note that recognizes that the operability of this instrumentation is not necessary when the main feedwater pumps are not operating and the auxiliary feedwater pumps are already in operation.
Georgia Power Company requests approval of this modification by April 29,1994.
The proposed change and the bases for the change are described in enclosure I to this letter. Enclosure 2 provides an evaluation pursuant to 10 CFR 50.92 showing that the proposed change does not involve significant hazards considerations. Instructions for incorporation of the proposed change into the Technical Specifications and a copy of the change is provided in enclosure 3.
In accordance with 10 CFR 50.91, the designated state oflicial will be sent a copy of this letter and all enclorures.
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Georgia Power h U. S. Nuclear Regulatory Commission Page 2 Mr. C. K. McCoy states that he is a vice president of Georgia Power Company and is authorized to execute this oath on behalfof Georgia Power Company and that, to the best of his knowledge and belief, the facts set forth in this letter and enclosures are tme.
GEORGIA POWER COMPANY By: [
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C. K. McCoy Sworn to and subscribed before me thisNda of ol d 1993.
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Maw (). &4h Notary Public WnWMtweA tee t..u t.m l
Enclosures:
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- 1. Basis for Proposed Change l
2.
10 CFR 50.92 Evaluation
- 3. Instructions for Incorporation and Revised Pages c(w): Geornia Power Company Mr. J. B. Beasley, Jr.
Mr. M. Sheibani NORMS U. S. Nuckar Regulatory Commission Mr. S. D. Ebneter, Regional Administrator Mr. I' 5 Hood, Licensing Project Manager, NRR l
Mr. B.1(. Bonser, Senior Resident Inspector, Vogtle State of Georcia Mr. J. D. Tanner, Commissioner, Dept. of Natural Resources l
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ENCLOSUREi VOGTLE ELECTRTC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS AUXILIARY FEEDWATER ACTUATIONINSTRUMENTATION BASIS FOR PROPOSED CHANGE l
Proposed Change The change will add a footnote to table 3.3-2 which states " Not required in MODE 2 j
when Auxiliary Feedwater is operating to supply the steam generators." The footnote will j
be applied to the applicable modes for functional unit 6.e of table 3.3-2.
Basis During a normal plant startup, entry is made into Mode 2 while feeding the steam l
generators using the auxiliary feedwater (AFW) system. The main feedwater (MFW) l pumps are then trip tested and started in Mode 2 when sufficient steam is being generated l
to operate the feedwater pump turbines. Both MFW pumps must be reset when I
performing an MFW pump trip test to prevent an AFW actuation. The current wording of the Technical Specifications requires that the plant enter a limiting condition for operation (LCO) when both MFW pumps are reset. These conditions could also result in an unnecessary AFW actuation signal if an MFW pump turbine trips during the time when l
AFW is supplying the steam generators. The proposed change to the Tcchnical
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Specifications will allow MFW pump testing without entering an LCO and will prevent unnecessary AFW actuation signals when AFW is already supplying feedwater to the steam generators.
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i ENCLOSURE 2 VOGTLE ELECTRIC GENERATING PLANT l
REQUEST TO REVISE TECHNICAL SPECIFICATIONS AUXILIARY FEEDWATER ACTUATION INSTRUMENTATION l
10 CFR 50.92 EVALUATION Pursuant to 10 CFR 50.92, Georgia Power Company has evaluated the proposed revision to the Technical Specifications and has determined that operation of the facility in l
accordance with the proposed amendment would not involve any significant hazards considerations.
Backcround During a normal plant startup, initial entry is made into Mode 2 while the auxiliary feedwater system is providing feedwater to the steam generators (SGs). The main feedwater turbine driven pumps are started after entry into Mode 2. MFW pump startup testing requires a trip test of the main feedwater pump. To prevent an AFW actuation signal during this trip test, both MFW pumps must be reset prior to the trip test. An LCO i
l must be entered to allow resetting ofboth MFW pumps to perform this test. During this time, the AFW system is already operating to maintain SG level. If the feedwater pump that is being started trips during its initial startup, an AFW actuation signal will be initiated, causing the AFW control valves to open and potentially increasing flow to the l
SGs.
This change will allow operation in Mode 2 with a nonoperating feedwater pump in the reset condition, provided that the AFW is providing water to the steam generators. If the nonoperating feedwater turbine trip is reset, the AFW start signal will not be received.
Therefore, the engineered safety features actuation (ESFAS) instrumentation of functional unit 6.e in Technical Specifications (TS) table 3.3-2 is considered to be inoperable if a feedwater pump turbine is reset from the tripped condition but not operating.
Analysis The current wordL,.f the TS requires this instrumentation to be operable prior to entry into Mode 2. During normal plant startups, the steam generators are fed by the AFW system until after entry into Mode 2. The first turbine driven MFW pump is started, i
tested, and aligned to st ply the SGs pdor to stopping the AFW pumps. Then the other l
MFW pump is started. In order to comply with the current TS requirements during the l
time when the AFW is supplying the SGs and one MFW pump is being started, it is necessary that the nonoperating MFW pump turbine be in the tripped condition. Under such circumstances a trip of the operating MFW turbine will initiate an unnecessary AFW E2-1 i
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f ENCLOSURE 2 (CONTIhTED)
VOGTLE ELECTRIC GENERATING PLANT
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REQUEST TO REVISE TECHNICAL SPECIFICATIONS i
AUXILIARY FEEDWATER ACTUATION INSTRUMENTATION 10 CFR 50.92 EVALUATIQH start signal because the AFW would already be in opention. In this case, operator action i
j may be required to prevent excess flow to the SGs since AFW flow control valves are signaled to open on an AFW start signal. The proposed TS change would avoid such -
conditions by allowing the nonoperating MFW turbine to be in the reset condition, provided that the SGs are being supplied by the AFW pumps. The wording of the change is such that the requirement for ESFAS instrumentation operability is unaffected when an MFW pump is providing feedwater to the SGs.
j The purpose of the instrumentation is to start the AFW system in the event of a loss of main feedwater to the SGs due to tripping of MFW pumps. Since the effect of the change i
to the TS is to allow the instrumentation to be inoperable only if the AFW is already supplying the SGs, the change will not affect the ability of the ESFAS instrumentation to i
perform its safety function.
I Conclusion Based on the above considerations, GPC has concluded the following concerning 10 CFR 50.92.
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The proposed change to the Technical Specifications does no+ " 've a significant increase in the probability or consequences of an accident previou@ e Muated because it only affects the AFW start signal during the time when the AFW system is already operatmg.
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The proposed change to the Technical Specifications does not create the possibility of a new or different kind of accident from any accident previously evaluated because it only affects the AFW start signal during the time when the AFW is already performing the function that the start signal is intended to initiate.
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ENCLOSURE 2 (CONTINUED)
VOGTLE ELECTRIC GENERATING PLANT REQUEST TO AEVISE TECHNICAL SPECIFICATIONS AUXILIARY FEEDWATER ACTUATION INSTRUMENTATION i
10 CFR 50.92 EVALUATION 3.
The proposed change to the Technical Specifications does not involve a significant t
reduction in a margin of safety because it will not change the requirement for operable AFW initiation instrumentation when the AFW is required to be operable but not operating. The change does not affect any accident or transient analysis assumptions; therefore, the margin of safety provided by operation according to the proposed change does not affect the safety limits or analyses used to demonstrate operation within safety limits.
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