ML20079A934
| ML20079A934 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 12/09/1994 |
| From: | Barkhurst R ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20079A936 | List: |
| References | |
| W3F1-94-0131, W3F1-94-131, NUDOCS 9501040194 | |
| Download: ML20079A934 (8) | |
Text
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Enter Operations, Inc.
Oma L A 700C6-0751 TN 504 739 6661 Ross P Barkhurst wavm n a, rw Yv 14 :13 W3F1-94-0131 1
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December 9,1994 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.
20555 s
Subject:
Waterford 3 SES Docket No. 50-382 License No. NPF-38 Technical Specification Change Request NPF-38-161 Gentlemen:
The attached description and safety analysis support a change to the Waterford 3 Technical Specifications (TS).
The proposed change modifies the requirement to perform a Moderator Temperature Coefficient (MTC) test near the end of each cycle.
This request constitutes a lead-plant submittal, submitted by Waterford 3 3
on behalf of the Combustion Engineering Owners Group (CE0G). CEN NPSD-911,
" Analysis of Moderator Temperature Coefficients in Support of a Change in The Technical Specification End of Cycle Negative MTC Limit", dated May, 1993 is enclosed for your review.
The proposed change has been evaluated in accordance with 10CFR50.91(a)(1) using criteria in 10CFR50.92(c) and it has been determined that the proposed change involves no significant hazards considerations.
The Plant Operations Review and Safety Review Committees have reviewed and accepted the proposed change based on the evaluation mentioned above.
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b Technical' Specification Change Request NPF-38-161 W3F1-94-0131 Page 2 i
December 9,1994
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l Should you have any questions or comments concerning this request, please contact Paal C3ropino at (504)739-6692.
Very truly yours, t
l R.P. Bar hurst Vice President, Operations Waterford 3 RPB/PLC/ssf
Attachment:
Affidavit NPF-38-161 cc:
L.J. Callan, NRC Region IV C.P. Patel, NRC-NRR R.B. McGehee N.S. Reynolds NRC Resident Inspectors Office Administrator Radiation Protection Division (State of Louisiana)
American Nuclear Insurers
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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l AFFIDAVIT R.P. Barkhurst, 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 j
the attached Technical Specification Change Request NPF-38-161; 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.
\\ L R.P. Barkhurst Vice President, Operations - Waterford 3 l
l STATE OF LOUISIANA
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l
) ss PARISH OF ST. CHARLES
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l Subscribed and sworn to before me, a Notary Public in and for the Parish and State above named this 9
- day of n e c e m s an,
, 1994,
. Yu P Ec. M Notary Public My Commission expires tw.m Litc_
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DESCRIPTION AND SAFETY ANALYSIS OF PROPOSED CHANGE NPF-38-161 The proposed change modifies TS 4.1.1.3.2c by adding a provision that eliminates the need to determine the Moderator Temperature Coefficient (MTC) upon reaching two-thirds of core burnup if the results of the MTC tests required in TS 4.1.1.3.2a and 4.1.1.3.2b are within a tolerance of i0.16X10-4 delta k/k/ F.
In addition the footnote identified by #(1) under applicability has been deleted. This provision was included via License Amendment No.16 and was applicable only during Cycle 2.
Removal of this footnote is purely administrative.
Existinq Soecification i
See Attachment A Proposed Specification See Attachment B TS 3.1.1.3 provides limitations on the MTC to ensure that the assumptions used in the accident and transient analysis remain valid through each fuel cycle. The requirements to measure the MTC at the beginning-of-cycle and near end-of-cycle (i.e., 2/3 expected core burnup) provide confirmation that the measured MTC value is within its limits and will remain in its limits throughout each cycle.
The proposed change modifies the MTC TS to eliminate the 2/3 cycle MTC surveillance if the results of the first two MTC surveillances fall within i0.16X10-4 delta k/k/ F of the calculated MTC (design value). However, if the results of the first two tests are not within that limit, then performance of the 2/3 cycle surveillance will be required.
The MTC relates a change in reactor coolant temperature to a change in core reactivity. A negative MTC means that an increase in coolant temperature causes a decrease in reactivity; a positive MTC means that an increase in coolant temperature causes an increase in reactivity. As such, the accident analysis looks at both overheating and overcooling of the reactor core.
In doing the analysis both the negative and positive MTC must be bounded. The positive MTC is used when considering overheating accidents with the limiting event being a CEA withdrawal accident from zero power. The negative MTC is used when considering overcooling accidents with the limiting event being the Steam Line Break (SLB) event.
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In a effort to improve the TS, the Combustion Enginaering Owners Group (CE0G) sponsored a task to analyze MTC data from CE plants.
The attached report, CE NPSD-911, documents the results of that task and provides the justification for this proposed TS change. The analysis shows that if the MTC at the beginning-of-cycle is within 10.16X10-4 delta k/k/ F of the design margin then the MTC at the end-of-cycle will also be within 10.16X10-4 delta k/k/ F of the design margin.
t The analysis used measured MTC data from several plants and compared that data to the calculated MTC. This was done to evaluate the methodology used in calculating the MTC.
Evaluating the data showed that if the MTC measured at the beginning-of-cycle is within 10.16X10-4 delta k/k/ F of the calculated MTC then the near end-of-cycle calculated MTC will be within 10.16X10-4 delta k/k/ F of the true MTC. Thus, if the method used to calculate the MTC is within 10.16X10-4 delta k/k/ F of the measured MTC at the beginning of tha cycle then t
the method adequately models the MTC for the entire cycle and the near end-of-cycle MTC surveillance is not required.
Based on the results of the enclosed analysis CE-NPSD-911, performance of the 2/3 cycle MTC surveillance should not be required if the beginning of cycle I
measured MTC are within i0.16X10-4 delta k/k/ F of the calculated MTC. As such, Waterford 3 is requesting a change to Technical Specification 3.1.1.3 that states that the 2/3 cycle MTC test need only be performed when the beginning-of-cycle MTC is not within 10.16X10-4 delta k/k/ F of the design value.
Waterford 3 anticipates the following benefits as a result of eliminating the l
2/3 cycle MTC surveillance:
1.
The surveillance requires operation at 93% power for 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />.
The reduction in generation is approximately 1500 MWhr(e).
2.
The surveillance occupies an operating shift and 2 Reactor Engineers for approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> during off-peak demand times.
3.
The surveillance requires support from the Nuclear Engineering and Analysis Department in Jackson, Mississippi for test predictions and plant support to process the work package.
4.
The surveillance requires cycling the primary and secondary plants --
possibly reducing equipment life and increasing required maintenance.
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s Based on the" above, elimination of the 2/3 cycle MTC surveillance would provide' for better use of current resources and reduce cycling of the plant which may have an adverse affect on plant performance while still maintaining the t
bounds of the safety analysis.
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Safety Analysis i
r 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 i
Involve a significant increase in the probability or consequences of any accident previously evaluated?
Response
No Under the proposed change, compliance with the TS Limiting Condition.for Operation is achieved through a surveillance program consisting-of beginning-of-cycle measurements, plant parameter monitoring, and explicit end-of-cycle MTC predictions.
The probability and consequences of an accident previously evaluated will not be increased because this change does not modify any assumptions used in the input to the safety analyses. The current safety calculations will-remain valid because the allowed range of MTC values will not change.
The Combustion Engineering analysis CE NPSD-911, demonstrates that if the j
startup test program has established that the core is operating as intended, and if the isothermal temperature coefficients measured at zero power during the cycle startup program, and at power during the first power ascension, fall within the design margin of 10.16X10-4 delta k/k/ F, then the end-of-cycle best estimate prediction will also be within i0.16X10-4 delta k/k/ F of true MTC.
Removing the footnote that was applicable during Cycle 2 is purely an administrative change.
Therefore, the proposed change will not involve a significant increase in the probability or consequences of any accident previously evaluated.
2.
Will operation of the facility in accordance with this proposed change c'reate the possibility of a new or different type of accident from any accident previously evaluated?
Response
No Plant operation and plant parameter TS limits will remain unchanged.
There are no new changes in plant design nor are any new failure modes introduced. CE NPSD-911 analysis determined that if the MTC at the beginning-of-cycle is within 10.16X10-4 delta k/k/ F of the design margin then the MTC at the end-of-cycle will also be within 10.16X10-4 delta k/k/
F of the design margin.
Removing the footnote that was applicable during Cycle 2 is purely an administrative change.
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 i
The margin of safety will not be reduced because the range of allowed temperature coefficients will not be changed. The surveillance program consisting of beginning-of-cycle measurements, plant parameter monitoring, j
and explicit end-of-cycle MTC predictions will ensure that the MTC remains within the range of acceptable values.
Removing the footnote that was applicable during Cycle 2 is purely an administrative change.
Therefore, the proposed change will not involve a significant reduction in a margin of safety.
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Safety and Sianificant 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 nrt 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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