ML20235M192

Application for Amends to Licenses DPR-53 & DPR-69,changing Tech Spec Figures 2.2-1,3.2-2 & 3.2-4 Re Axial Power Distribution Trip Limit,Linear Heat Rate Axial Flux Offset & DNB Axial Flux Offset Control Limits.Fee Paid

ML20235M192
Person / Time
Site:	Calvert Cliffs
Issue date:	09/25/1987
From:	Tiernan J BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20235M195	List: ML20235M192 ML20235M250
References
NUDOCS 8710060094
Download: ML20235M192 (5)

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. BALTIMORE GAS AND ELECTRIC CHARLES CENTER P. O. BOX 1475 BALTIMORE, MARYLAND 21203 I I

JOSEPH A.TIERNAN vice Passiotwv NucLEAn Ewenov l 1

September 25, 1987 l U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Reauest for Amendment

REFERENCES:

(A) Setpoint Methodology Topical Report, CENPD-199-P, Rev.1-P- A.

(B) 48FRl4870, April 6,1983.

Gentlemen:

The Baltimore Gas and Electric Company hereby requ'sts an Amendment to its Operating License Nos. DPR-53 and DPR-69 for Calvert Cliffs Unit Nos.1 & 2, respectively, with the submittal of the proposed changes to the Technical Specifications.

CIIANGE (BG& E FCR 87-3003)

Change Figure 2.2- 1, 3.2-2, and 3.2-4 of the Unit I and Unit 2 Technical Specifications as shown on the marked-up copies attached to this transmittal. i l

LISCUSSION l This proposed change will revise the following Unit I and Unit 2 Technical Specification figures:

1. Figure 2.2-1 (Axial Power Distribution Trip Limiting Safety System Settings (APD LSSS)). This figure is associated with Technical Specification 2.2- 1 (Table 2.2- 1, item 8) and is widened in both the positive and negative directions below 70% power.

2. Figure 3.2-2 (Linear 11 eat Rate Axial Flux Offset Control Limits). This figure is associated with Technical Specification 3.2.1 (Linear lleat Rate Limiting Condition for Operation (L11R LCO) and is widened in the negative h direction below 50% power. /;A B710060094 B70925 00 PDR p

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r Document Centrol Desk September 25, 1987 Page 2 L

3. Figure 3.2-4 (DNB Axial- Flux Offset Control Limits). Th*s  ; figure is associated 'with Technical Specification 3.2.5 (DNB Limiting Condition for Operation (DNB LCO) and is widened in the negative direction below 50%

f power.

During plant startup, when power is below the APD trip bypass of 15% power, the measured Axial Shape Index (ASI) can be more negative than the current APD trip limit.

This is caused by xenon and reactivity feedback induced perturbations in the axial power shape associated with rapidly changing power and temperatures. Technical Specification 2.2-1 requires that the plant remain below 15% power until the ASI falls within the APD LSSS operating band, or the reactor will trip. An APD trip at this power level is not a safety concern, since the induced perturbations in the axial shape will usually dampen out before a significant power level is reached (i.e., in the 20-40% power range). In addition, at low power levels sufficient conservatism exists in the current APD LSSS, DNB LCO, and LHR LCO to permit relaxation of the ASI operatir.g bands without compromising any safety margin.

DETERMIN ATION OF SIGN!FICANT HAZARDS This proposed change has been evaluated against the standards in 10 CFR 50.92 and has been determined to involve no significant hazards considerations, in that operation of the facility in accordance with the proposed amendment would not:

(i) involve a significant increase in the probability or consequences of an accident previously evaluated; or The APD trip is not credited directly in any transient analysis for Calvert Cliffs Unit I and Unit 2 (i.e., its performance is not modeled). Instead the APD trip is cred:ted indirectly.

By virtue of the Setpoint methodology, the APD LSSS ensures that the Specified Acceptable Fuel Design Limit (SAFDL) on fuel centerline melt is not violated during certain Design Basis Events (DBE). A transient simulation is therefore not required except for those events which result in system changes not considered in the APD LSSS analysis (e.g., CEA drop which resr.its in a violation of the Power Dependent Insertion Limits, Technical Specification Figure 3.1 -2). The transient simulations determine the margin degradation for those events not covered and the corresponding Required Overpower Margin (ROPM) data to be factored into the Limiting Conditions for Operation. This methodology is described in Chapter 1 of Combustion Engineering's (C-E) approved setpoint methodology topical report, [Ref.

( A)]. Therefore, the proposed change to the APD LSSS will not impact the transient analyses of Chapter 14. ,

I At low power levels, the operating band set by the DNB LCO and LHR LCO is I credited, at zero power conditions, in the following accident analyses:

1. Control Element Assembly (CEA) Withdrawal,

2. Excess Load, and

3. CEA Ejection.

The CEA Ejection analysis considers axial shapes of positive ASI values.

Since no changes are proposed in the positive ASI region of the LCOs, the

l Document Control Desk l ' September 25, 1987 Page 3 l

CEA E.iection event will not be affected. Thus, the proposed changes will l only affect the CEA Withdrawal and Excess Load events.

L An evaluation of the CEA Withdrawal and Excess Lsad analyses showed that the proposed changes will make the transient minimum DNBR more limiting.

However, the impact is very small and the current minimum DNBR values are high enough for these events that the DNBR design limits will not be violated. Therefore, the proposed changes to the DNB LCO and LHR LCO do not significantly impact the Unit 1 Cycle 9 and Unit 2 Cycle 8 transient analyses.

(ii) create the possibility of a new or different type of accident from any accident previously evaluated; or The proposed changes to the APD LSSS, DNB LCO, and LHR LCO do not result in any change in the configuration of the plant, equipment design or equipment used nor does it require any changes in the accident analysis methodology.

Therefore, the proposed changes will not create the possibility of a new or different kind of accident from any accident previously evaluated.

(iii) involve a significant reduction in a margin of safety.

1 The proposed changes were evaluated for potential impact on the following items:

a. The margin to fuel centerline melt limits

b. The margin to DNB limits

c. The margin to the LOCA peak linear heat rate limits j

d. The core power versus planar radial peaking factor LCO 1 (Technical Specification Figure 3.2-3a) I

e. The Thermal Margin / Low Pressure LSSS (Technical Specification Figures 2.2-2 and 2.2-3) 1

f. The core power versus integrated radial peaking factor LCO  !

(Technical Specification Figure 3.2-3c) j l

The evaluation of each of these items is discussed below.

a. Marcin to Fuel Centerline Melt Limits An evaluation of the Calvert Cliffs Unit i Cycle 9 and Unit 2 Cyde 8 APD LSSS analysis was performed. This evaluation showed that at pov er levels less than 70 % of rated power there exists sufficient conservatism in the current APD LSSS to accomodate the proposed change.

The proposed change still contains sufficient margin to the current i fuel centerline melt safety limits. Therefore, the proposed change I does not significantly impact the margin to the fuel centerline melt limits. l

b. Marcin to DNB L.imits An evaluation of the Calvert Cliffs Unit 1 Cycle 9 and Unit 2 Cycle 8 i DNB LCO enalysis was performed. This evaluation showed that at power i l

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Document Control Desk September 25, 1987 Page 4 levels less than 50 % of rated power there exists sufficient conservatism in the current DNB LCO to accomodate the proposed change.

The proposed change still contains sufficient margin to the current DNB safety limits. Therefore, the proposed change does not significantly impact the margin to the DNB limits.

c. Marcin to the LOCA Peak Linear Heat Rate Limits An evaluation of the Calvert Cliffs Unit ! Cycle 9 and Unit 2 Cycle 8 LliR LCO analysis was performed. This evaluation showed that at power levels less than 50 % of rated power there exists sufficient conservatism in the current LIIR LCO to accomodate the proposed change.

The proposed change still contains sufficient margin to the current LOCA peak linear heat rate limits. Therefore, the proposed change does not significantly impact the margin to the LOCA peak linear heat rate limits,

d. Core Power Versus Planar Radial Peakinn Factor LCO The core power versus planar radial peaking factor tradeoff curve ensures that the APD LSSS remains conservative if the measured unrodded planar radial peaking factor is greater than the Technical Specification limit of 1.70. This limit curve was reanalyzed using the proposed APD LSSS changes. The results showed that there is no impact on the Unit 1 Cycle 9 and Unit 2 Cycle 8 tradeoff curves,

c. Thermal Marcin/ Low Pressure LSSS The Calvert Cliffs Unit I Cycle 9 and Unit 2 Cycle 8 Thermal Margin / Low Pressure LSSS was reanalyzed because the APD LSSS is credited in that analysis. This analysis was performed using the proposed APD LSSS changes. The results showed that there is no impact on the Thermal Margin / Low Pressure LSSS.

f. Core Power Versus Intenrated Radial Peakinn Factor LCO The Calvert Cliffs Unit 1 Cycle 9 and Unit 2 Cycle 8 core power versus integrated radial peaking factor tradeoff curve was reanalyzed because the APD LSSS and DNB LCO are credited in that analysis. This analysis was performed using the proposed APD LSSS and DNB LCO changes. The results showed that there is no impact on the tradeoff curves.

The methodology used in the safety evaluation is found in C-E's approved setpoint methodology topical report [ Reference ( A)].

The Commission has provided guidance concerning the application of the standards for determining whether a significant hazards consideration exists by providing certain examples of amendments that are considered least likely to involve significant hazards considerations (Reference (B)]. The proposed changes are most like example (vi) because the proposed changes will allow an expanded operating envelope for ASI at low power levels; however, the results of the changes are clearly within all acceptable criteria.

.______________D

. Document Control Desk September 25, 1987 Page 5 Therefore, based on the above considerations, BG&E has -determined that this change does not involve a significant hazards consideration.

E6FETYCOMMITTEE REVIEW These proposed' changes to the Technical Specifications and our determination of significant hazards have been reviewed by our Plant Operations and Off-Site Safety Review Committees, and they have concluded that implementation of these changes will not result in an undue risk to the health and safety of the public.

FEE DETERMINATION Pursuant to 10 CFR 170.21, we are including BG&E Check No. ( 1912793 )

in the amount of $150.00 to the NRC to cover the application fee for this request.

Very truly yours, STATE OF MARYLAND :

TO WIT:

COUNTYOFCALVERT :

Joseph A. Tiernan, being duly sworn states that he is Vice President of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the foregoing response for the purposes therein set forth; that the statements made are true and correct to the best of his knowledge, information, and belief; and that he was authorized to provide the response on behalf of said Corporation.

WITNESS my lland and Notarial Seal: >W C 0 Notary Public My Commission Expires: ph h /j/998 V ( B 7[W 3t4) M / 7 8 7 Date JAT/JES/Imt Attachments cc: D. A. Brune, Esquire J. E. Silberg, Esquire R. A.Capra,NRC S. A.McNeil, NRC W. T. Russell, NRC T. Foley/D. C. Trimble, NRC T. Magette, DNR