ML20073P560
| ML20073P560 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 05/17/1991 |
| From: | Woodard J ALABAMA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20073P562 | List: |
| References | |
| NUDOCS 9105220086 | |
| Download: ML20073P560 (6) | |
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n,,r May 17, 1991 Docket No. 50-348 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Vashington, DC 20555 Joseph M. Farley Nuclear Plant - Unit 1 NRR Valver of Compliance and Amendment Request for ESP Response Time for Steam Line Isolation Technical Specification Gentlemen:
By letter dated October 26, 1990, Alabama Power Company submitted a technical specification amendment to support implementation of the RTD Bypass Elimination modification and an increased steam generator tube plugging limit for Farley Nuclear Plant Unit 1.
On March 8, 1991, the NRC issued Amendment No. 87 to the Facility Operating License NPF-2, which included the requested technical specification changes and the related NRC safety evaluation. The Amendment No. 87 technical specification changes have been incorporated, the RTD Bypass Elimination modification has been l
I implemented, and Farley Nuclear Plant (FNP) Unit 1 is proceeding with post-refueling outage plant startup activities.
However, it was not identified that the ESF response time for steam line isolation from high steam flow coincident with T low-lov could exceed the current limit of 9 l
seconds,asdiscovereddurinflheconductofRTDresponsetimetestingon May 17, 1991.
The deletion of the RTD bypass manifold now necessitates the incorporation of an additional 2 seconds for this ESF function response time. Before FNP Unit 1 can enter operational Mode 1, the Unit 1 Technical Specifications must be revised; therefore, Alabama Power Company is requesting an NRR vaiver of compliance until the attached technical specification change can be approved by the NRC.
VCAP-12613, Revision 2, "RTD Bypass Elimination Licensing Report for J. M.
Farley Nuclear Plant Units 1 and 2," provided the basis for the safe operation of the Parley units following elimination of the RTD bypass 1.
manifold system and the subsequent use of fast response RTD's with wells installed directly in the RCS hot and co.d leg flow streams.
The use of fast response RTD's installed in wells required increasing the technical specification overtemperature delta-T (OToT) reactor trip response time I
from 4 seconds to 6 seconds, which was consistent with the maximum l
allowable time delay assumed in the accident analyses.
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U. S. Nuclear Regulatory Commission Page 2 During response time testing for Unit 1 startup, it was discovered that the technical specification response time for steam line isolation on high steam flow coincident with T low-low could not be satisfied for the main steam isolation bypass valve D Since the T low-lov signal is derived from the same RTD's, a response time increase,of 2 seconds is also required for this ESF function. Alabama Power Company therefore proposes that the ESF response time for the main steam line isolation function by high steam line flow coincident with T low-lov be changed from 9 seconds to 11 seconds. Upon the granting'ol a temporary valver of compliance, FNP vill be able to demonstrate compliance with the Technical Specification for main steam line isolation response time and continue Unit 1 startup activitles. is the information request'd in NRC letter dated February 22, 1990 concerning Temporary Valvers of Compliance. Alabama Power Company has determined that the proposed changes do not involve a significant hazards consideration.
In accordance with 10 CFR 50.92 a significant hazards consideration evaluation is provided as Attachment 2.
A revised page to the Unit 1 Technical Specifications is included as Attachment 3.
Alabama Power Company's Plant Operations Reviev Committee has reviewed the proposed changes and the Nuclear Operation Reviev Board vill review the changes at a future meeting.
A copy of these proposed changes is being sent to Dr. C. E. Fox, the Alabama State Designee, in accordance vita 10 CFR 50.91(b)(1).
If you have any questions, please advise.
Respectfully submitted, 1
ALABAMA POVER COMPANY wy 0 0$.L M p
J. D. Voodard JDV/MGE: map 8.8 Attachments SVORN TO AND SUBSCRIBED BEFORE ME ra :
Mr. S. D. Ebneter THIS
/7 DAY OF ] //<.,
1991
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Mr..'. T. Ho!.fman
/[i,//[/fLII-Mr. G. F. Maxwell 4
1t f Dt, C. E. Fox Notary Pub) c j
My Commiss on Expires:
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F ATTACHMENT 1 Information Identitled in NRC 1,etter dated February 22, 1990 1.
Requirements for Which a Vaiver Is Requested:
Technical Specification 4.3.2.3 requires an Engineered Safety Feature Response Time Test for " Steam Flov in Two Steam Lines -
High Coincident with T
--Low-Lov".
The current response time required is $9.0 secon85?
A valver is requested to increase the response time to $11.0 seconds.
2.
Circumstances Requiring Prompt Action:
By letter dated October 26, 1990, Alabama Power Company submitted a technical specification amendment to support implementation of the RTD Bypass Elimination modification and an increased steam generator tube plugging limit for Farley Nuclear Plant Unit 1.
On March 8, 1991, the NRC issued Amendment No. 87 to the Facility Operating License NPF-2, which included the requested technical specification changes and the related NRC safety evaluation.
The Amendment No. 87 technical specification changes have been incorporated, the RTD Bypass Elimination modification has been implemented, and Farley Nuclear Plant (FNP) Unit 1 is proceeding with post-refueling outage plant startup activities.
However, it was not identified that the ESF response time for steam line isolation from high steam flow coincident with T low-lov could exceed the current limit of 9 seconds, as discovered for the main steam isolation bypass valves during the conduct of RTD response time testing on May 17, 1991.
Before FNP Unit I can enter operational Mode 1, the Unit 1 Technical Specifications must be revised; therefore, Alabama Power Company is requesting a valver of compliance until a technical specification change can be approved by the NRC.
3.
Compensatory Actions:
FNP is following the limitations imposed by Technical Specification 4.3.2.3 for main steam line isolation response time. These limitations require that the steam line isolation valves remain closed in Modes 2 and 3 and entry into Mode 1 is prohibited.
4.
Safety Significance and Potential Consequences:
The high steam flow coincident with T low-lov ESF function is not taken credit for in any accident aEdlysis including main steam pipe rupture, non-LOCA, containment response or in equipment qualification (superheat) outside of containment.
Protection for these events are provided by other protection l
signals.
Main steam line isolation on high steam flow in two steam lines coincident with T lov-lov is provided as a diverse I
signal that providesnoprimaIi'protectionforanyevent.
Protection for main steam pipe breaks is provided by the overpower protection, OToT, and lov pressurizer pressure reactor trip functions and the lov steam line pressure, high steam line differential pressure, lov pressurizer pressure, High-1 l
containment pressure ESF functions.
Primary main steam line isolation protection is provided by the lov steam line pressure and the High-2 containment pressure ESF functions.
Therefore, the increase in response time from 9 seconds to 11 seconds vill have no effect on any previously analyzed accident.
5.
Duration of the Request:
The valver of compliance is requested until approval of the technical specification change.
6.
Significant Hazards Consideration:
See Significant Hazards Evaluation contained in Attachment 2.
7.
Environmental Consequences:
Since no credit in accident analysis is taken for the high steam flov and T low-lov ESF function, the increase in the steam line isolatl8n time response from 9 to 11 seconds does not involve any significant change in the types of effluents that may be released offsite and no significant increase in the individual or cumulative occupational radiation exposure.
Therefore, this valver of compliance does not involve any irreversible environmental consequences.
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1 ATTACl!HENT 2 Significant flazards Evaluation for the Joseph H. Parley Nuclear Plant Unit 1 Increase in ESP Response Time for Steam Line Isolation (Steam Flow in Two Steam Lines--Bigh Coincident with T,,,--Low-Lov) 10 CFR 50.92 EVALUATION Fursuant to 10 CFR 50.92 each application for amendment to an operating license must be reviewed to determine if the proposed change involves a significant hazards cor. sideration. The amendment, as defined belov, describing the technical specification change associated with increase in the response time for low-lov has been steam line isolation by high steam flow coincident with T,,$derations.
reviewed and deemed not to involve significant hazards cons The basis for this determination follovs.
PROPOSED CHANGES The proposed amendment involves the following technical specification change to the Engineered Safety Features (ESP) response time for steam line isolation on low-lov. The proposed high steam flow in two steam lines coincident with T,6 seconr' change involves en increase from the current value of to a new value of 11 seconds. This increase in response time is consistent with the previously NRC approved response time for resistance temperature detector (RTD) bypass manifold elimination and the use of fast response RTD's located in the hot and cold leg piping.
EVALUATION Hodification to Table 3.3-5 (ESF Response Times) for Item 5(a) steam line isolation on high steam flow coincident with T low-lov is proposed.
This modification vill make all technical specifica,tl8n response times affected by RTD manifold bypass elimination consistent.
The allovable time delays for generating the reactor protection and steam break protection actuation signals previously included 2 seconds for the RTD bypass manifold loop by RCS T,yBelay.
transport When the RTD's are relocated to the RCS loops for direct temperature measurement, the 2 second time delay should be reallocated to the RTD and well response time, which had previously been done for the overtemperature delta-T (OT6T) reactor trip function.
The high steam flow coincident with T lov-lov ESF function is not taken credit for in any accident analysis iS.luding main steam pipe rupture, non-LOCA, I
l containment response or in equipment qualification (superheat) outside of containment.
Protection for these events are provided by other protection signals.
Main steam line isolation on high steam flow in two steam lines low-low is provided as a diverse signal that provides no coincident with T,,for any event.
primary protection Protection for main steam pipe breaks is provided by the overpower protection, OT6T, and low pressurizer pressure reactor trip functions and the lov steam line pressure, high steam line differential pressure, low pressurizer pressure, High-1 containment pressure ESF functions.
Primary main steam line isolation protection is provided by the lov steam line pressure and the High-2 containment pressure ESF functions. Therefore, the increase in response time from 9 seconds to 11 seconds vill have no effect on any previously analyzed accident.
Significant Hazards Evaluation (Continued)
Page 2 of 2 Based on the information presented above, the following conclusions can be reached with respect to 10 CFR 50.92:
-1.
The ESF response time increase for this steam line isolation function does not significantly increase the probability or consequences of an accident previously evaluated in the FSAR. This function provides no primary protection for any transient in the FSAR.
No new performance requirements are being imposed on any system or component.
Consequently, overall plant integrity is not reduced. These changes have no effect on any dose calculations. Therefore, the probability or consequences of an accident vill not increase.
2.
The ESF response time increase of 2 seconds for the high steam flow coincident with T low-low function does not create the possibility of a new or different kl8d of accident from any previously evaluated in the FSAR.
This response time is not an initiator for any transient. No new accident scenarios, failure mechanisms, or limiting single failures are introduced as a result of this 2 second increase. The response time increase does not challenge or prevent the performance of any safety-related system during plant transients. Therefore, the possibility of a new or different kind of accident is not created.
3.
This change does not involve a significant reduction in the margin of safety.
All primary trip functions and ESF actuations are unaffected by the increase in this ESF response time. Therefore, the change to the response time does not effect the results of nny accident analysis, and the margin of safety is maintained and not significantly reduced.
Based upon the preceding information, it has been determined that the ESF response time increase of 2 seconds for steam line isolation on high steam flow in two steam lines coincident with T'"'
low-lov does not involve a significant hazards consideration.
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