ML20236H106
| ML20236H106 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 07/02/1998 |
| From: | Dugger C ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20236H110 | List: |
| References | |
| W3F1-98-0033, W3F1-98-33, NUDOCS 9807070085 | |
| Download: ML20236H106 (10) | |
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I Entngy Operttions, Inc.
Kdk.ma, LA 700(E;-0751 Tel 504 739 6660 Charlos M. Dugger
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ce f es dent Operanons W3F1-98-0033 A4.05 PR July 2,1998 U.S. Nuclear Regulatory Commission Attn: Document Contro Desk Washington, D.C. 20555 1
Subject:
Waterford 3 SES Docket No. 50-382 License No. NPF-38 Technical Specification Change Request NPF-38-207 Gentlemen:
The attached description and safety analysis support a change to the Waterford 3 Technical Specifications (TS). The proposed change modifies the ACTION Requirements for Technical Specification 3/4.3.2 for the Emergency Feedwater Actuation Signal (EFAS). A change to the Technical Specification Bases Section 3/4.3.2 has been included to support this change. The objective of this change is to add a restriction on the period of time a channel of EFAS instrumentation can remain l
in the tripped condition.
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l On June 3,1997 and supplemented on May 1,1998, Waterford 3 submitted l
proposed changes to Technical Specification (TS) 3/4.3.2 as NPF-38-198 and NPF-38-198, Supplement 1, respectively. The proposed changes modify the l
ACTION Requirements for Technical Specification 3/4.3.2 for the Safety injection System Sump Recirculation Actuation Signal (RAS) due to an identified single failure vulnerability, Other Engineered Safety Features Actuation System (ESFAS)
Instrumentation circuits were reviewed to ascertain if a single failure could prevent the fulfillment of a design safety function. This TS change was prepared because a p)l{
similar potential was determined to exist for Steam Generator Differential Pressure Instrumentation (SGDPI) associated with the Emergency Feedwater Actuation Signal. With one channelin a tripped condition, combined with a failure of another channel of SGDPI and a Main Steam Line Break or Feedwater Line Break, the t
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3 Technical Specification Change Request NPF-38-207 W3F1-98-0033 Page 2 July 2,1998 l
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automatic isolation of a faulted steam generator from emergency feedwater would not have occurred as assumed by the Waterford 3 safety analysis.
The existing Technical Specification is included in Attachment A. Attachment B contains the revised specification as proposed in this change request. Those changes are annotated with revisions bars that identify the changes specific to the EFAS (NPF-38-207) as well as RAS (NPF-38-198, Supplement 1) changes. As discussed with C.P. Patel on February 26,1998, it is expected that Proposed Change NPF-38-198 for RAS will be issued prior to NPF-38-207 for EFAS. As a result, the EFAS change "/ould require a supplement because both the RAS and EFAS proposed changes affect the same pages (3/4 3-18a and B 3/4 3-1). To accommodate and clarify the changes to ACTIONS 19 and 20 as well as the Bases for the combined RAS and EFAS changes, the proposed specification combining NPF-38-198 and NPF-38-207 changes is provided in Attachment C.
Additionally, a Bases change which was approved by the Plant Operating Review Committee in accordance with 10CFR50.59 is provided as insert 2 in Attachment C.
It is requested that this 10CFR50.59 approved Bases change be issued along with this requested TS Amendment.
The circumstances surrounding this change do not meet the NRC's criteria for exigent or emergency review. However, Waterford 3 is currently operating with administrative controls in place due to non-conservative ESFAS Technical Specifications. Entergy Operations requests the effective date for this change be within 60 days of approval.
This proposed change has been evaluated in accordance with 10CFR50.91(a)(1),
using the criteria in 10CFR50.92(c), and it has been determined that this request involves no significant hazards consideration.
Technical Specification Change Request NPF-38-207 W3F1-98-0033 Page 3 July 2,1998 Should you have any questions or comments concerning this request, please contact Mr. Early Ewing at (504)739-6242.
Very truly yours, C. M. Dugger Vice President, Operations l
Waterford 3 CMD/ PRS /ssf Attachments:
Affidavit NPF-38-207 l
cc:
E.W. Merschoff, NRC Region IV l
C.P. Patel, NRC-NRR i
J. Smith N.S. Reynolds NRC Resident inspectors Office 1
American Nuclear Insurers Administrator Radiation Protection Division (State Of Louisiana) l l
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In th.e matter of
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Entergy Operations, incorporated
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Docket No. 50-382 Waterford 3 Steam Electric Station
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AFFIDAVIT Charles Marshall Dugger, being duly sworn, hereby deposes and says that he is Vice President Operations - Waterford 3 of Entergy Operations, incorporated; that he is duly authorized to sign and file with the Nuclear Regulatory Commission the attached Technical Specification Change Request NPF-38-207; that he is familiar with the content thereof; and that the matters set forth therein are true and correct to the best of his knowledge, information and belief.
0}Lk LW c w Charles Marshall Dugger Vice President Operations - Waterford 3 STATE OF LOUISIANA
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) ss PARISH OF ST. CHARLES
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Subscribed and sworn gbefore me, a ta Public in and for the Parish and State above named this of day of y
.1998.
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Notary Public V
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i My Commission expires
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O-g DESCRIPTION AND NO SIGNIFICANT HAZARDS EVALUATION OF PROPOSED CHANGE NPF-38-207 The proposed change requests a change to the ACTION Requirements for Technical Specification 3/4.3.2 for the Emergency Feedwater Actuation Signal (EFAS). This.
change revises the allowed outage time for a channel of EFAS to be in the tripped condition from " prior to entry into the applicable MODE (S) following the next COLD SHUTDOWN" to the more restrictive time limit of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> and adds a shutdown requirement. The applicable process measurement circuit requirements in ACTION 13 were placed in ACTIONS 19 and 20 for the EFAS change. In ACTION 14, Steam Generator Level - High is incorrectly listed as a functional unit affected by the Steam Generator Pressure - Low process measurement circuit and is being removed as a typographical error in this proposed change. Also to be more succinct in ACTION 14, the Functional Unit Bypassed / Tripped corresponding to the Steam Generator Pressure
- Low process measurement circuit, Steam Generator AP (EFAS), is being changed to Steam Generator AP 1 and 2 (EFAS). With the change the affected functional units become explicitly rather than being im,nlicitly identified. Additionally, the 3.0.4 exemption is being removed from the ACTION for the tripped condition. A change to the Technical Specification Bases Section $!4.3.2 has been included to support this change.
Existina Technical Specification
. See Attachment A Proposed Technical Specification See Attachment B Proposed Technical Specification Combinina NPF-38-198. Supplement 1 and NPF-38-207 See Attachment C Backaround The Emergency Feedwater Actuation Signal (EFAS) is initiated by a 2 out of 4 logic for Steam Generator Differential Pressure Instrumentation (SGDPI). Waterford 3 TS 3.3.2.b, Table 3.3-3 allows continued operation with an inoperable channel of EFAS SGDPI placed in the tripped condition. If a channel of EFAS SGDPI is in the tripped condition at the time of a MSLB and another channel of EFAS SGDPl fails, then an inadvertent EFAS could be activated, which would cause feeding of the faulted SG.
These events under certain circumstances could adversely affect the Waterford 3 safety analysis.
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This postulated condition could potentially occur when one channel of the EFAS SGDPI logic is placed in the tripped condition. There is one EFAS for each steam generator which, upon actuation, will provide EFW to the required generator. The EFAS is actuated with the requisite channels of one of the following: 1) steam generator level low coincident with SGDPI between the two steam generators high or 2) steam generator level low coincident with no steam generator pressure Iow trip. Normally an EFAS will occur when two-out-of-four channels are actuated. Current Technical 1
Specifications allow an inoperable channel to be placed in either bypass (resultant two-out-of-three-logic to actuate) or trip (resultant one-out-of-three-logic to actuate) for an indefinite period. With one channelin the tripped condition, and a Main Steam Line Break (MSLB) then occurs on the associated steam generator coincident with a failure I
of another channel of SGDPI, EFW would be activated and sent to the faulted steam l
generator. The Waterford 3 safety analysis assumes that the excess Reactor Coolant System (RCS) cooldown and return to power associated with the MSLB will be terminated when the faulted steam generator empties. If additional EFW were added, the RCS cooldown would be extended and the return to power may be more severe.
This may result in exceeding the Waterford 3 Departure from Nucleate Boiling Ratio Limit. The event would then be terminated when operators take action to isolate the feedwater to the ruptured steam generator.
A similar postulated condition could occur when an inadvertent EFAS is activated during a Feedwater Line Break (FLB). In this scenario, EFW would be activated to both steam generators, but since the EFW comes off a common header to both steam generators, the majority of the EFW would flow out of the break. This is because the broken line would be at containment pressure while the intact steam generator would be at a pressure on the order of 1100 psia. This would resuit in a total loss of feedwater, and would be terminated when the operators take manual action to isolate the feedwater from the faulted generator.
Description and Safety Considerations The current TS ACTION 13 requires that, with one inoperable EFAS SGDPI channel, the channel be placed in the bypass or tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. With 2 channels l
of EFAS SGDPI inoperable, TS ACTION 14 requires that one inoperable channel be placed in trip and the other inoperable channel be placed in bypass. in ACTION 13, continued operation is allowed in this configuration until entry into the applicable MODES following the next COLD SHUTDOWN. If the failures occurred at the start of a operating cycle, there is the potential for a channel to be in the tripped condition for up to a maximum of 18 months. In ACTION 14, continued operation is allowed in the l
tripped condition until performance of the next required CHANNEL FUNCTIONAL TEST, which could be in three months.
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o Waterford 3 proposes to limit the time that one channel of EFAS SGDPI can be in the tripp' d condition to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> which is reasonable time for repair. The revised e
ACTIONS have been renumbered as ACTIONS 19 and 20. As the bypass function
. places EFAS SGDPl system in a 2 out of 3 logic, use of the bypass feature is not a concern, because with the resulting logic, a single failure would not cause an inadvertent EFAS. ACTION 19 has been revised to refer to the condition of one inoperable channel. The channel may be placed in the bypassed condition until the next entry into COLD SHUTDOWN. If placed in the tripped condition, a time limit of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is being imposed until the channel must be removed from the tripped condition.
The 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for the channel to be in the tripped condition is based on operating experience, which has demonstrated that a random failure of a second channel l
occurring during the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> period is a low probability event. This allowed outage time for the tripped condition is consistent with the currently allowed time for the analog
- Combustion Engineering plants that do not have indefinite bypass. The Combustion Engineering (CE) analog plants use a time limit of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> in NUREG 1432, " Standard Technical Specifications ~- Combustion Engineering Plants." Waterford 3 is considered to be a digital plant as it uses an Engineered Safety Features Actuation System (ESFAS) designed by CE and, therefore, does not have a specified time that a channel of ESFAS can remain in the tripped or bypassed condition. The Waterford 3 ESFAS is designed for channel independence. The locations of the sensors and the points at which the sensing lines are connected to the process loop have been selected to provide physical separation of the channels, thereby precluding a situation in which a
- single event could remove or negate a protective function. The routing of cables from protective system transmitters is arranged so that the cables are separated from each other and from power cabling to minimize the likelihood of common event failures. This includes separation at the containment penetration areas. In the control room, L
protective system trip channels are located in individual compartments. Mechanical and thermal barriers between these compartments minimize the possibility of common event failure. Outputs from the components in this area to the control boards are isolated so that shorting, grounding, or the application of the highest available local voltages (120 VAC,125 VAC) do not cause channel malfunction.
Since the allowed outage time for a channel of EFAS SGDPI is being limited to 48 3
hours, this is considered an off-normal operation and a single failure is not required to be postulated during a Design Basis Accident in the accident analysis. ACTION 20 l
addresses the condition in which two channels of EFAS are inoperable. One channel i
l must be placed in the bypassed condition and the other placed in the tripped condition.
j A time limit 'of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is imposed due to the channel being placed in the tripped l
l-condition.
The probability of the inadvertent EFAS is remote. The coincident MSLB or FLB are deemed limiting fault accidents since the probability of occurrence of these events are
. extremely low for Waterford 3. Finally, a failure of another channel of EFAS SGDPl i
which produces the inadvertent EFAS feeding the faulty generator is also unlikely. The i
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probability of the three conditions (an EFAS SGDPI channel in tripped condition, the coincident MSLB or FLB, and the failure of another channel of EFAS SGDPI) to occur at the same time is extremely low. Therefore, the allowed outage time of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is acceptable.
Due to the addition of a specified allowed outage time, the 3.0.4 exemption is not applicable to the ACTION for the tripped condition. The 3.0.4 exemption is still applicable for the bypassed condition as the allowed outage time for the bypassed condition remains until entry into the applicable MODES following the next entry into COLD SHUTDOWN, as before. This is specified in the ACTIONS and explained in the Bases.
An expanded Bases, consistent with NUREG 1432, " Standard Technical Specifications
- Combustion Engineering Plants," has been added to support this change.
No Significant Hazards Evaluation The proposed change described above shall be deemed to involve a significant hazards consideration if there is a positive finding in any of the following areas:
1.
Will operation of the facility in accordance with this proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response
No The proposed revision to the TS changes the allowed outage time that a channel of EFAS SGDPI can be in the tripped condition from a maximum of approximately 18 months when one channel is inoperable and 92 days when two channels are inoperable to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. If a channel were in the tripped condition and a single failure occurred (failure of one other channel of EFAS SGDPI ), an inadvertent EFAS signal would be generated. During a Design Basis MSLB or FLB Accident, this single failure would send EFW to the faulted steam generator.
The Waterford 3 safety analysis assumes that the excess Reactor Coolant System (RCS) cooldown and return to power associated with the MSLB will be terminated when the faulted steam generator empties. If additional EFW were added, the RCS cooldown would be extended and the return to power may increase.
Reducing the time that a channel of EFAS SGDPI can be placed in the tripped condition will reduce the probability of this scenario occurring during a Design Basis Accident. Since the allowed outage time for a channel of EFAS SGDPI is being limited to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, this is considered an off-normal operation and a single failure is not required to be postulated during a Design Basis Accident in the 4
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accident analysis. Reducing the time the channel can be placed in the tripped condition and thus, the exposure time to this scenario, would not be an accident initiator._ The proposed change of being more conservative relative to allow outage time in the tripped condition will not affect the assumptions, design parameters, or results of any accident previously evaluated.
i Therefore, the proposed change will not involve a significant increase in the probability or consequences of any accident previously evaluated.
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Will operation of the facility in accordance with this proposed change create the possibility of a new or different type of accident from any accident previously evaluated?
Response
No.
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The proposed change does not alter the design or configuration of the plant. The l
proposed change provides a more conservative allowed outage time for the
~ channel to be in the tripped condition. There has been no physical change to plant systems, structures or components nor will the proposed change reduce the ability of any of the safety-related equipment required to mitigate Anticipated Operational Occurrences or accidents. The configuration required by the
. proposed specification is permitted by the existing specification.
Therefore, the proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
3.
Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?
Response
No The proposed change provides a more conservative allowed outage time for the channel to be.in the tripped condition. By reducing the allowed outage time, the probability is reduced that a single failure (failure of one channel of EFAS SGDPI with one channel in the tripped condition) would occur that would send EFW to I
the faulted steam generator. Therefore, the only change to the' margin of safety L
- would be an increase. Since the allowed outage time for a channel of EFAS i
'SGDPI is being limited to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, this is considered an off-normal operation and a single failure is not required to be postulated during a Design Basis Accident in the accident analysis. The proposed changes do not affect the limiting conditions for operation or their bases.
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_Therefore, the proposed change will not involve a significant reduction in a margin of safety.
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Safety and Significant Hazards Determination-Based on the above safety analysis, it is concluded that: (1) the proposed change does not constitute a significant hazards consideration as defined by 10CFR50.92; and (2) there is a reasonable assurance that the health and safety of the public will not be endangered by the proposed change; and (3) this action will not result in a condition which significantly alters the impact of the station on the environment as described in the NRC final environmental statement.
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