ML20217D492
| ML20217D492 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 03/25/1998 |
| From: | Dugger C ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20217D496 | List: |
| References | |
| W3F1-98-0023, W3F1-98-23, NUDOCS 9803300038 | |
| Download: ML20217D492 (11) | |
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Enti y perItioni, Inc.
y Kilkana. LA 700fE>-0751 Tel 504 739 6660 Charles M. Dugger
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r ce Pres dent. Operata;ns W3F1-98-0023 A4.05 PR March 25,1998 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Waterford 3 SES Docket No. 50-382 License No. NPF-38 Technical Specification Change Request NPF-38-177, Revision 1 Gentlemen:
Entergy on July 18,1996, via letter W3F1-96-0096, submitted a Technical Specification Change Request for Technical Specification 3.9.8.1, " Shutdown Cooling and Coolant Circulation High Water Level" and Technical Specification 3.9.8.2, " Shutdown Cooling and Coolant Circulation Low Water Level."
Entergy has re-reviewed Technical Specification Change Request NPF-38-177. This review identified a discrepancy in the Technical Specification Change Request. This revision of the Technical Specification Change Request corrects the discrepancy in the original submittal and incorporates additional changes to improve the clarity of
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the Technical Specifications. This revision of the Technical Specification Change Request supersedes the original submittalin its entirety. The Safety Analysis and
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Significant Hazards Consideration of the original submittal were not affected in any i
material aspect, but we have elected to provide a complete submittal to account for editorial impact primarily in the Description.
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The original Technical Specification Change Request changed the Applicability of TS 3.9.8.1 and TS 3.9.8.2 by changing the words " reactor pressure vessel flange" to
" irradiated fuel assemblies" in establishing a reference for the water level in the reactor cavity. The use of these words made Technical Specification Action 9803300038 980325P
.PDR--ADOCK 05000302 P
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., Technical Specification Change Request NPF-38-177, Revision 1
' W3F1-98-0023 Page 2 March 25,1998 3.9.8.2a inconsistent with the Applicability Statement of Technical Specification 3.9.8.1. Specifically, with the noted changes, Technical Specification Action 3.9.8.2a with one shutdown cooling train inoperable required the water level to be raised to 23
- feet above the reactor pressure vessel flange which is a higher level than required by Technical Specification 3.9.8.1. Technical Specification 3.9.8.1 required only one shutdown cooling train to be operable and in operation with the water level 23 feet above the fuel seated in the reactor pressure vessel.
This revision to the Technical Specification Change Request uses the words, " fuel seated in the reactor pressure vessel," in Technical Specifications 3.9.8.1 and 3.9.8.2, including Technical Specification Action 3.9.8.2a, instead of the words
" reactor pressure vessel flange." This change corrects the discrepancy and makes Technical Specification Action 3.9.8.2a consistent with the Applicability of Technical Specification 3.9.8.1. This supplement also changes the action statement of Technical Specification 3.8.1.2 and Technical Specification Bases 3/4.9.8 to use the words, " fuel seated in the reactor pressure vessel," rather than the words, " reactor pressure vessel flange," in making reference to the water level in the reactor cavity.
This change will make the wording of Technical Specification 3.8.1.2 and Technical Specification Bases 3/4.9.8 the same as the wording of Technical Specifications 3.9.8.1 and 3.9.8.2 in making reference to the water level in the reactor cavity.
Five editorial changes are also made in this revision to improve the clarity of Technical Specification 3.9.8.2.
Please contact Early Ewing at (504) 739-6242 or Tim Gaudet at (504) 739-6666 should there be any questions regarding this request.
Very truly yours C.M. Dugger Vice President, Operations LWaterford 3.
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Attachment:
NPF-38-177, Revision 1 v
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Technical Specification Change Request NPF-38-177, Revision 1 W3F1-98-0023 Page 3 March 25,' 1998 cc:
E.W. Merschoff (NRC Region IV)
C.P. Patel (NRC-NRR)
J. Smith N.S. Reynolds NRC Resident inspectors Office Administrator Radiation Protection Division (State of Louisiana)-
American Nuclear insurers t
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the 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 Supplement to Technical Specification Change Request NPF-38-177, Revision 1; 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.
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'V Charles Marshall Dugger Vice President Operations - Waterford 3 STATE OF LOUISIANA
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Subscribed and sworn to before me, a Notary Public in and for the Parish and State above named this a r S day of
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,1998.
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Notary Public My Commission expires
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DESCRIPTION AND NO SIGNIFICANT HAZARDS EVALUATION OF PROPOSED CHANGE NPF-38-177, Revision 1 This Technical Specification amendment request is a request to revise Technical Specification 3.9.8.1 " Shutdown Cooling and Coolant Circulation High Water Level,"
and Technical Specification 3.9.8.2, " Shutdown Cooling and Coolant Circulation Low Water Level," to change the minimum water level above the fuel assemblies seated in the reactor vessel at which the Shutdown Cooling (SDC) System is required to be
' maintained operable, or be in operation. The Technical Specification amendment changes Technical Specification 3.8.1.2, " Electric Power Systems A.C. Sources
- Shutdown," and Technical Specification Bases 3/4.9.8, " Shutdown Cooling and Coolant Circulation," to make the wording consistent with Technical Specifications 3.9.8.1 and 13.9.8.2. Editorial changes are also made to improve the clarity of Technical J Specification 3.9.8.2.
Existing Technical Specifications See Attachment A Proposed Technical Specifications See Attachment B Description The function of the SDC system is to provide core cooling while the reactor is shutdown, by removing the decay heat being generated in the core. The SDC system is comprised of two SDC boat exchangers, two Low Pressure Safety injection (LPSI) pumps and their associated piping and valves. The SDC heat exchangers are cooled by the Component Cooling Water (CCW) system. The SDC system is used to keep the reactor vessel temperature at or below 140*F, once the vessel is cooled to the SDC entry temperature of 350*F.
Currently, Technical Specification 3.9.8.1 requires that in mode 6 at least one train of 1 SDC shall be operable and in operation when water level in the reactor cavity is equal to or greater than 23 feet above the reactor pressure vessel flange. Technical Specification 3.9.8.2 requires that in mode 6 with water level less than 23 feet above the reactor pressure vessel flange, two independent trains of SDC shall be operable and at least one SDC train shoW be in operation.
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The proposed Technical Specification amendment changes the minimum water level, from 23' feet above the reactor pressure vessel flange to 23 feet above the fuel seated in the reactor vessel, at which the SDC System is required to be maintained operable, or be in operation. Specifically, Technical Specification 3.9.8.1 is being changed to -
require one shutdown cooling train to be operable and in operation when the water level
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above the top of the fuel seated in the reactor vessel is greater than or equal to 23 feet.
Technical Specification 3.9.8.2 is being changed to require two independent shutdown j
cooling trains to be operable and at least one shutdown cooling train to be in operation when the water level above the top of fuel seated in the reactor vessel is less than 23 feet. Technical Specification 3.8.1.2 and Technical Specification Bases 3/4.9.8 are being changed to use the same wording as Technical Specifications 3.9.8.1 and 3.9.8.2 in making reference to the water level in the reactor cavity.
Five editorial changes are also made in this revision, specifically, changing:
(1)"With less than the required shutdown cooling trains operable" to "With one of the required shutdown cooling train inoperable"in Technical Specification Action 3.9.8.2a, (2) " trains" to " train" in Technical Specification Action 3.9.8.2a, (3) "in operation" to
" OPERABLE and in operation" in Technical Specification Action 3.9.8.2b, (4)
" OPERABLE" to " OPERABLE and in operation" in the note for Technical Specification LCO 3.9.8.2, and (5) changing the word " operation" to the phrase " operating status as soon as possible" in Technical Specification Action 3.9.8.2b, making the wording of Technical Specification Action 3.9.8.2b the same as the action statement of Technical Specification 3.9.8.1. These changes improve the clarity of Technical Specification 3.9.8.2 The applicable safety issues or Technical Specification bases were identified, and each safety issue or Technical Specification bases is herein discussed:
One SDC Train in Operation, Sufficient Cooling Capacity Technical Specification bases 3/4.9.8 states that the requirement that at least one shutdown cooling train be in operation ensures sufficient cooling capacity is available to remove decay heat and maintain the water in the reactor pressure vessel below 140*F as required during the refueling mode. The Technical Specifications will still require one shutdown cooling train be in operation, and therefore, this Technical Specification bases is unaffected.
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l One SDC Train in Operation, Sufficient Coolant Circulation Technical Specification bases 3/4.9.8 states that the requirement that at least one shutdown cooling train be in operation ensures sufficient coolant circulation is maintained through the reactor core to minimize the effects of a boron dilution incident i
and prevent boron stratification. The Technical Specifications will still require one shutdown cooling train be in operation, and therefore, this Technical Specification bases is unaffected.
Rupture Of An irradiated Fuel Assembly Technical Specification 3.9.10.1, " Refueling Operations Water Level - Reactor Vessel Fuel Assemblies," states that at least 23 feet of water shall be maintained over the top of the reactor pressure vessel flange during movement of fuel assemblies. Technical Specification bases 3/4.9.10 states the restrictions on minimum reactor vessel water
~ level ensure sufficient water depth is available to remove 99% of the assumed 10%
- iodine gap activity released from the rupture of an irradiated fuel assembly. Also, the fuel handling accident analysis is a function of the water depth over the irradiated fuel assemblies in the reactor core. Technical Specification 3.9.10.1 will not be changed and will be complied with, and therefore, the assumptions related to iodine removal and the fuel handling accident will be preserved.
Reactor Core Cooling Technical Specification bases 3/4.9.8 states that 23 feet above the reactor pressure vessel flange ensures adequate time is available to initiate emergency procedures to cool the core.
An analysis was performed to demonstrate there is sufficient water inventory in the reactor cavity with 23 feet of water above the top of the fuel seated in the reactor vessel to allow the operators to recover from the loss of SDC prior to boiling in the reactor vessel. The analysis was performed in two steps.
- 1) The first step was to determine the time to boiling in the event of a loss of shutdown cooling.
- 2) The second step was to establish a time at which the core would be uncovered due to boil-off, following a loss of shutdown cooling.
The initial pool temperature was assumed to be 140*F. The nozzle dams are assumed j
to be installed. The cooling of the vessel using natural circulation is no longer possible with the nozzle dams installed. Also, the available inventory for heat-up is less with the nozzle dams installed since the water in the steam generator could not be credited.
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1 The volume of water in the cold and hot legs, lower plenum, core bypass, and the downcomer was conservatively ignored for the time to boil and the core uncovery calculations. The available pool volume contributing to heat-up was limited to the upper plenum, the active and inactive core regions, and the cavity pool inventory directly above and in the immediate vicinity of the reactor vessel flange. The volume above the active fuel and the upper plenum in addition to the cavity pool inventory above the twenty (20) foot MSL, volume above vessel flange, were credited for the time to core uncovery calculation.
1 The time to boil was calculated based on a standard heatup calculation using the following relationship:
dT/dt = Q/pVcp The 1979 ANS best estimate decay heat curve was used for the decay heat, Q, in the core.
The time to core uncovery was calculated by determining the mass (m) needed to uncover the core, m = pV, and dividing the mass (m) by the rate of mass dissipated due to boiling, dm/dt = Q/hg The time to core uncovery includes the time first needed to reach boiling.
The time to boil was determined to be 1.00 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />, and the time to core uncovery was determined to be 27.74 hours8.564815e-4 days <br />0.0206 hours <br />1.223545e-4 weeks <br />2.8157e-5 months <br />. Both results are based on twenty three (23) feet of water above the top of the fusi seated in the reactor vessel, approximately 10 feet above the reactor flange, and the decay heat at four days after shutdown.
Containment Closure The ability to establish containment closure is important as a defense in depth measure. The analysis of water inventory establishes the operators would have significant time within which to close the containment prior to the initiation of boiling in the reactor vessel. Waterford 3 has also demonstrated the ability to quickly close the equipment hatch during mid loop operations, approximately 15 minutes, and has implemented measures to ensure the expeditious closure of the equipment hatch.
These measures include, for example, review of procedures among cognizant personnel, equipment hatch area walk downs, and staging of equipment and tools.
Although personnel are not specifically designated to implement these measures when the water level is twenty three feet above the top of the fuel assemblies, the equipment and tools necessary for the closure of the equipment hatch are staged and personnel are available to close the equipment hatch and establish containment closure as expeditiously as possible. Waterford 3 will implement the appropriate measures for the condition with water level twenty three feet above the fuel assemblies to ensure i
containment closure can be established prior to the initiation of boiling. Therefore, the i
ability to establish containment closure will be maintained.
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l Benefit This Technical Specification Change Request revision is a Cost Beneficial Licensing Action (CBLA). This change will allow Waterford 3 personnel to start work on the shutdown cooling system earlier in the refueling outage, and save on average, about 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> of critical path time per refueling outage. The estimated savings of this Technical Specification Change Request is about 13.5 million dollars over the life of the plant.
4 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:
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Will operation of the facility in accordance with this proposed change involve a significant increase in the probability or consequence of any accident?
Response
No The operation of the facility in accordance with this change does_not involve an increase in the probability of any accident.
Changing the water level at which the Shutdown Cooling (SDC) System is required to be maintained operable or be in operation will not increase the probability or J
consequences of an accident. The design, operation, or configuration of the SDC system will not be changed.
At least one shutdown cooling train will be in operation to ensure sufficient cooling capacity is available to remove decay heat and maintain the water in the reactor pressure vessel below 140*F as required during the refueling mode.
At least one shutdown cooling train will be in operation to ensure sufficient coolant circulation is maintained through the reactor core to minimize the effects of a boron dilution incident and prevent boron stratification. Technical Specification 3.9.10.1,
" Refueling Operations Water Level-Reactor Vessel Fuel Assemblies," will be complied with, and therefore, the assumptions related to lodine removal and the fuel handling accident will be preserved.
Sufficient time, approximately 1.00 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />, will be available to the operators to initiate compensatory measures to preclude the initiation of core boiling in the unlikely event SDC should be loss.
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l possibility of a new or different kind of accident from any accident previously evaluated?
Response
No The operation of the facility in accordance with this proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed change will not affect the design, configuration, or operation of the SDC system, and therefore there are no new modes of failure introduced.
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Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?
Response
No
- Operation of the facility in accordance with this proposed change will not involve a significant reduction in a margin of safety.
The calculation of the time to the initiation of boiling based on 23 feet above the top of the fuel seated in the reactor vessel, at four days after shutdown, demonstrates there is significant time available, approximately 1.00 hour0 days <br />0 hours <br />0 weeks <br />0 months <br />, to the operators within which to take compensatory measures to preclude the initiation of boiling. The calculation shows that based on 23 feet of water above the reactor flange there is 2.04 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to the initiation of boiling. Although there is a reduction in the time to the initiation of boiling, compensatory measures could be taken within a few minutes to restore SDC, and thus, there is still a significant margin available to the operators within which to preclude the initiation of boiling. Thus, the margin of safety is not significantly reduced.
The time to core uncovery was determined to be 27.74 hours8.564815e-4 days <br />0.0206 hours <br />1.223545e-4 weeks <br />2.8157e-5 months <br /> based on four days after
-shutdown and water level twenty three (23) feet above the fuel assemblies seated in the reactor vessel.
Safety and Significant Hazards Determination Based on the above safety analysis, it is concluded: (1) the proposed change does not constitute a significant hazards consideration as defined by 10CFR50.92; and (2) there is a reasonable assurance 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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i NPF-38-177, Revision 1 ATTACHMENT A Existing Technical Specifications 4