ML20236G494
| ML20236G494 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 07/30/1987 |
| From: | Randazza J Maine Yankee |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20236G499 | List: |
| References | |
| 8667L-HFJ, MN-87-87, NUDOCS 8708040286 | |
| Download: ML20236G494 (6) | |
Text
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- POMCOMM
- AUGUSTA A E 04336 h
July 30, 1987 MN-87-87 Proposed Change #132 United States Nuclear Regulatory Commission Attention:
Document Control Desk Hashington, D. C.
20555
References:
(a)
License No. DPR-36 (Docket No. 50-309)
(b) MYAPCo Letter to USNRC dated January
'2, 1987 (MN-87-04)
Proposed Change #128 - Cycle 10 Technical Specifications
Subject:
Proposed Change No.132 - Technical Specification 3.10, Revised LOCA Monitoring Limits for Incore Monitoring System Inoperable Gentlemen:
In accordance with 10 CFR 50.90, Maine Yankee proposes a change to Technical Specifications addressing the LOCA Monitoring Limits when the Incore Monitoring System is Inoperable. The change is as follows:
Replace Page 3.10-4 of Specification 3.10.C with the enclosed revised page.
The proposed change would modify the Technical Specifications to increase the flexibility of core operation when the Incore Monitoring System is
-inoperable. Maine Yankee uses the Incore Monitoring System to monitor the LOCA LHGR limits under normal operating conditions.
If the incore alarms become inoperable, power operation can continue under Technical Specification 3.10.C.3.1.1.
This specification applies a penalty factor to the last incore LOCA Linear Heat Generation Rate (LHGR) measurement and establishes additional CEA and symmetric offset restrictions.
The penalty factor accounts for the maximum possible loss in margin due to peaking increases that could result from operation within these restrictions. Operation for a maximum of two weeks is allowed under these restrictions.
The specification, therefore, establishes conditions under which the LOCA LHGR limits will be maintained.
The proposed specification increases the flexibility of core operation by separating the penalty factor into CEA and symmetric offset components.
The proposed specification expresses the penalty as a function of CEA movement relative to the CEA position at the time of the measurement.
Finally, the proposed specification defines two separate ranges of symmetric offset to cover the most likely conditions of core operation.
The proposed specification is more flexible than the existing specification in allowing trade-offs between CEA and symmetric offset restri(.tions. Both specifications, however, perform the same function of establishing conditions under which operation within the LOCA LHGR limits is ensured.
A detailed description of the basis for the Technical Specification 3.10.C.3.1.1 and justification for the revised LOCA Monitoring Limits when the Incore Monitoring System is Inoperable is provided in Attach en, C.
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M AINE Y ANKEE ATOMIC POWER COMPANY United States Nuclear Regulatory Commission Page Two Attention:
Document Control Desk MN-87-87 l
i Maine Yankee has evaluated the proposed changes and has determined that they do not involve a significant increase in the probability or consequences of an accident previously evaluated; increase the possibility of a new or different kind of accident from any accident previously evaluated; or involve a significant reduction in a margin of safety.
Therefore, these proposed changes do not include a significant hazards consideration as defined in 10 CFR 50.92.
The evaluation is included in Attachment A.
This proposed change has been reviewed by the Plant Operation Review Committee and the Nuclear Safety Audit and Review Committee.
The Plant Operations Review Committee has concluded that the proposed Technical Specification changes do not constitute an unreviewed safety question.
A State of Maine representative has been sent a copy of this proposed change.
A license amendment application fee of $150.00 is enclosed per 10 CFR 50.71.
Very truly yours, MAINE YANKEE ATOMIC POWER COMPANY John B. Randazza Executive Vice President JBR/bjp Attachments:
(A) Description of Proposed Change and Sigiiricant Hazards Evaluation (B) Proposed Technical Specification Changes for Revised LOCA Monitoring Limits when the Incore Monitoring System is Inoperable (C) Basis and Justification fer Revised LOCA Monitoring Limits when the Incore Monitoring System is Inoperable cc: Mr. Victor Nerses Mr. Hilliam T. Russell Mr. Cornelius F. Holden Mr. Pat Sears Mr. Clough Toppan STATE OF MAINE Then personally appeared before me, John B. Randazza, who being duly sworn did state that he is Executive Vice Pres'< dent of Maine Yankee Atomic Power Company, that he is duly authorized to vecute and file the foregoing request in the name and on behalf of Maine Yr# u Atomb Power Company, and that the statements therein are true to the W M his knowledge and belief.
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V Notary Public STEPHEN D. EVANS NOTARY PUBUC. MAINE 8667L-HFJ uy c0MMLSS10N EXPlRES OCTOBER 3.
l MAINE YANKEE QTOMIC POWER COMPANY l
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ATTACHMENT A HN-87-87 l
1 Description of Proposed Change and 4
Significant Hazards Evaluation i
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MAINE YANKEE ATOMIC POWER COMPANY ATTACHMENT A
-MN-87-87 Description of ProDosed Chanae The proposed change.provided in Attachment B would modify the Technical Specifications to reflect revised LOCA Monitoring Limits which could be used i
when the Incore. Monitoring System is inoperable.
Maine Yankee currently uses the Incore Monitoring System to monitor the LOCA Linear Heat Generation Rate (LHGR) Limits.
If the incore alarms become inoperable, power operation can be continued as allowed by Technical Specification 3.10.C.3.1.1.
This specification places limits on CEA position and axial symmetric offset, and based on these restrictions, penalizes the last incore LHGR measurement for potential power peaking increases and establishes a maximum allowable power level for operation.
The following conditions must be met:
o CEAs are maintained above the 100% power insertion limit.
o Excore symmetric offset remains within 10.05 of the value measured when the last incore readings were taken.
o Core power is reduced to less than or equal to P (% of rated power), where l
P is given by:
P = 0.85 x R, where R is the minimum ratio of (Linear Heat Rate Permitted by Specification 3.10.C.1 x 100)
(Latest Measured Peak Linear Heat Rate Corrected to 100% Power)
The intent of. this specification is to permit continued. operation based on the latest measured LOCA LHGR margin to limits. The penalty factor of 0.85 accounts for the m1ximum possible loss in margin due to peaking increase that could result from operation within the restricted CEA and symmetric offset limits.
The flyspeck analysis used in the determination of the Reactor Protection System setpoints forms the basis of this penalty factor, which is evaluated each cycle, i
The proposed specification separates this combined penalty factor into CEA l
and symmetric offset components and expresses the penalty as a function of CEA i
movement relative to the CEA position at the time of the measurement.
In addition, the proposed specification defines two symmetric offset ranges to l
cover the most likely conditions of core operation.
The actual LOCA LHGR Limits specified in Technical Specification 3.10.C.1, which are determined using an approved ECCS Evaluation Model and meet the criteria established in i
10 CFR 50.46 and 10 CFR 50, Appendix K, remain the same.
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Significant Hazards Evaluation The proposed changes to the Technical Specifications for revised LOCA Monitoring Limits when the Incore Monitoring System is Inoperable for the Maine Yankee plant have been evaluated against the standards of 10CFR50.92 and have been determined to not involve a significant hazards consideration.
These proposed changes do not.
i i
1.
Involve a significant increase in the probability or consequence of I
an accident previously evaluated.
Operation of the plant at the revised LOCA Monitoring Limit when the j
Incore Monitoring System is Inoperable does not increase the probability of a LOCA.
Furthermore, Maine Yankee has evaluated j
operation of the plant during Cycle 10 for Non-LOCA events and has established Non-LOCA Limits independent of LOCA Limits, Reference 4
(b). The imposition of a LOCA Monitoring Limit when the Incore Monitoring System is Inoperable further restricts operation and does i
not affect Non-LOCA events.
Therefore, the proposed changes do not increase the probability of an accident previously evaluated.
The LOCA Limits specified in Technical Specification 3.10.C.1 are i
determined using methods found to be in compliance with 10CFR50.46 and 10CFR50 Appendix K.
These regulations establish the criteria which assure that the consequences of LOCAs are acceptable.
The revised LOCA Monitoring Limits when the Incore Monitoring System is Inoperable assures adequate margin exists to the LOCA LHGR Limits in Technical Specification 3.10.C.I.
Therefore, operation of the plant at the revised LOCA Monitoring Limit when the Incore Monitoring System is Inoperable does not significantly increase the consequences of LOCAs.
Furthermore, operation with the revised limits does not j
increase the consequences of Non-LOCA events for the reason stated in
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the previous paragraph.
Therefore, the proposed changes do not
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increase the consequences of an accident previously evaluated.
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2.
Create the possibility of a new or different kind of accident from any previously evaluated.
1 The proposed change revises the LOCA Monitoring Limit when the Incore
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Monitoring System is Inoperable. Operating within the revised limits assures adequate margin exists to the LOCA LHGR Limits specified in Technical Specification 3.10.C.1.
These limits meet the criteria of 10 CFR 50, Appendix K.
Furthermore, operation with the revised LOCA Limits for Non-LOCA events does not create the possibility of a new or different kind of accident for the reason stated in Item 1.
Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any previously evaluated.
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'3.
Involve a-significant reduction in a margin of safety.
The' LOCA Limits were specified in Technical Specification 3.10.C.1 are determined using methods found to be in compliance with
'10CFR50.46 and-10CFR50 Appendix K.
These regulations establish the criteria which assure that adequate margin of safety exists for LOCAs.
The. revised LOCA Monitoring Limits when the Incore Monitoring SystemLis Inoperable assures adequate margin exists to the LOCA LHGR Limits in Technical Specification 3.10.C.1.
Furthermore, operation with the revised limits does not reduce a margin of safety for Non-LOCA events for the reason stated in Item 1.
Therefore, the proposed changes do not involve a significant reduction in.a margin of safety, i
' Maine Yankee has-concluded that the proposed changes to Technical Specifications do.not involve a significant hazards consideration as defined by 10 CF1 50.92.
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