NRC-87-0177, Application for Amend to License NPF-43,revising Tech Specs 3/4.2.3, Min Critical Power Ratio & 3/4.7.9, Main Turbine Bypass Sys & Associated Bases to Clarify Operation W/ Moisture Separator Reheater Out of Svc.Fee Paid

Application for Amend to License NPF-43,revising Tech Specs 3/4.2.3, Min Critical Power Ratio & 3/4.7.9, Main Turbine Bypass Sys & Associated Bases to Clarify Operation W/ Moisture Separator Reheater Out of Svc.Fee Paid

ML20148Q126
Person / Time
Site:	Fermi
Issue date:	01/27/1988
From:	Sylvia B DETROIT EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20148Q130	List: ML20148Q133 NRC-87-0177, Application for Amend to License NPF-43,revising Tech Specs 3/4.2.3, Min Critical Power Ratio & 3/4.7.9, Main Turbine Bypass Sys & Associated Bases to Clarify Operation W/ Moisture Separator Reheater Out of Svc.Fee Paid
References
CON-NRC-87-0177, CON-NRC-87-177 TAC-65400, NUDOCS 8801290337
Download: ML20148Q126 (9)

Text

F 1

D. Ralph SyMa f Gwr bce Pres dent Detroit Edison ==r...,

_ ~.

January 27, 1988 NIC-87-0177 U. S. !bclear Regulatory Comission Attn: Docunent Control Desk Washington, D. C. 20555

References:

1) Fermi 2 NIC Docket tb. 50-341 tHC License No.15'F-43

2) Detroit dison to hTC, "Fermi 2 Operation with Roduced Feedwater Tenterature and Moisture Separator Reheater Out-of-Service (T/C-65400) ,"

dated Septenber 11,1987 (tGC-87-0129)

Subject:

Proposed Technical Specification (License Anerdnent)

Change - Mininum Critical Power Ratio (3/4.2.3) ard Main AIIbine_BypMS_Sys19m_DL4_.7& _ _

On Septenber 11, 1987, Detroit Fdison committed to the hTC (Refererce

2) to provide a proposed Technical Specification change clarifying the bases of operation with a Moisture Separator Reheater (MSR) out-of-service . Pursuant to 10CFR50.90, Detroit Fdison Conpany hereby proposes to anerd Operating License 13T-43 for the Fermi 2 plant by incorporating the enclosed changes into Technical Specification 3/4.2.3, Mininum Critical Power Ratio and 3/4.7.9, Main Airbine Bypass System. Detroit dison also proposes to arend Bases 3/4.2.3 ard 3/4.7.9.

Detroit Eison has evaluatcd the proposed Technical Specifications against the criteria of ICCFR50.92 and determined that no significant hazards consideration is involved. The Fermi 2 Cnsite Review Organization has approved and the !bclear Safety Review Group has reviewed these proposed Technical Specification changes ard corcurs with the enclosed determinations.

Pursuant to 10CFR170.12(c), enclosed with this amerdnent is a chcck for one lurdred fif ty dollars ($150.00) . In accordance with ICCFR50.91, Detroit dison has provided a copy of this letter to ttm State of Michigan.

8801D90337 0801D7 k PDR ADOCK 05000341 pa y row ,)

1. 253f

.. i

• USNIC f January 27, 1988 ,

NIC-87-0177 Page 2  ;

l If you have any questions, please contact Ms. Lynne Gocdman at (313) 586-4211.

Sincerely, Enclosure cc: Mr. A. B. Davis Mr. E. G. Greenman ,

Mr. T. R. Quay l Mr. W. G. Rogers .

alpervisor, Myanced Planning and Review Section, Michigan Public Service Connission i

i i

i l

f t

i i

i

USNBC

' January 27, 1988

!. NBC-87-0177 Page 3 I, B. RALPH SYLVIA, .do hereby affirm that the foregoing statements are ba3ed on facts and cire'.mtances whi._: are true and accurate to the best of my knowledge and belief.

'B'.

J PS4H SYINiA ks Group Vice President On this 27M day of APA(LwP , 1988, before me personally appeared B. Ralph Sylvla, being"first duly sworn and says that he executed the foregoing as his free act and deal.

"fkhtim. $l . keld Notary Public KAREN M. REED Mcnroe County, Mich, feng stifEn Expires M31 M' #

E Enclosure to NBC-87-0177 Page 1 I HAdGnuurO/bISCUSSICE

'Ite current Technical Specifications 3/4.2.3, Mininum Critical Power i Ratio, and 3/4.7.9, Main 'Ibrbine Bypass System, are not explicit with regards to the operating limitations with the Moisture Separator Reheater (MSR) out-of-service. The proposed change request:

A. Modifies 'Ibchnical Specification 3/4.7.9 by specifying operating limitations of the MSR.

B. Demonstrates conservatism to the existing transient analysis and clarifies that the limits in Technical Specification 3/4.2.3, Figure 3.2.3-1 (Curve B) bounds the operating scenario for the MSR out-of-service.

C. Provides an additional limitation (Curve C) to 'Itchnical Specification 3/4.2.3, Figure 3.2.3-1 for the operating scenario of an inoperable main turbine bypass aM MSR out-of-service.

The 'Ibchnical Specification Figure 3.2.3-1 provides two operating limit Mininum Critical Power Ratio (MCPR) curves which are based on the delta-CPRs resulting from the following transients:

Curve A provides the bCPR limit assuming operation above 25 percent rated thermal power with both the MSR and main turbine bypass system operable. The curve was developed based upon the operating ICPR limits for a Rod Withdrawal Error transient (UFSAR, Section 15.4.2) and a Main Turbine Trip with 'Ibrbine Bypass Failure transient (UFSAR, Section 15.2.3) . The analysis of the Main 'Ibrbine Trip with 'Ibrbine Bypass Failure takes credit for the steam flow (10 percent of rated) to tha MSR. As shown in UFSAR Figure 15.0-1, the operating limit MCPR for the two limiting transients is bounded by the limits of 1.24 0 T = 0 and 1.25 @ T = 1 as provided in Curve A.

Curve B provides the !CPR limit assuming operation above 25 percent rated thermal power with the MSR operable and the main turbine bypass system inoperable. The curve was developed based upon the operating ICPR limits for a Feedwater Controller Failure with Inoperable Turbine Bypass transient. The analysis of the Feedwater Controller Failure transient also takes credit for steam flow (10 percent of rated) to the MSR. With the postulated inoperability of the main turbine bypass system, the Feedwater Controller Failure becomes the most limiting transient and yields a FCPR limit of 1.24 @ T = 0 aM 1.310 T = 1.

l ..

Enclosure to NBC-87-0177 Page 2 The main turbine bypass system is an active bypass system designed to open the bypass valves in the event of a turbine trip to decrease the severity of the pressure transient. Each valve is sized to pass a nominal 13 percent reactor steam flow in the full-open position for a controlled total bypass of approximately 26 percent reactor steam flow. The primary purpose of the MSR is to inprove cycle efficlency by using primary system steam to heat the high pressure turbine exhaust before it enters the la-pressure turbines. In doing so, it also provides a passive steam bypass flow of about 10 percent that mitigates the early effects of over-pressure transients.

The main turbine bypass system and the MSR conbines for a total (active and passive) reactor steam flow bypass capability of 36 percent. Curve A represents the MCPR limitations when both the MSR and rain turbine bypass system are operable. This represents a total reactor steam flow bypass capability of 36 percent. Curve B represents the MCPR limitations when the main turbine bypass system is inoperable. This represents a total reactor steam flow bypass capability of 10 percent (through the MSR) . Curve B represents the more limiting transient scenario of the two curves.

A Main Turbine Trip with Turbine Bypass Failure transient assuming an inoperable MSR results in a W PR limit of 1.19 0 T = 0 and 1.30 0 T = 1. This transient is bounded by the MCPR limits for a Feedwater Controller Failure with Inoperable Turbine Bypass (Curve B). Additionally, the consequences of a Feedwater Controller Failure, assuming an operable rain turbine bypass system and inoperable MSR, results in a less severe (smaller delta-CPR's) transient than the Feedwater Controller Failure with Inoperable Turbine Bypass (Curve B) . The consequences are less severe because the Feedwater Controller Failure event with inoperable MSR provides approximately 26 percent bypass flow capability while the Feedwater Controller Failure event with inoperable main turbine bypass provides approxirately 10 percent bypass flow capability.

Considering the Main '1brbine Trip with Turbine Bypass Failure and the Feedwater Controller Failure transients, the resulting MCPR limits from an operational coMition with the MSR inoperable ard main turbine bypass operable would no' result in a pressure transient as severe as that postulated for a Fecdwater Controller Failure with Inoperable Turbine Bypass. Thus, these MCPR limits are bounded by those limits in Curve B. Since Curve B is bounding, clarifying the applicability of Curve B when the MSR is inoperable or when the main turbine bypass is inoperable, would allow the plant greater operational flexibility should there ever be a need to perform preventative or corrective maintenance above 25 percent ratcd thermal power.

Enclosure to NFC-87-0177 Page 3 .

Additionally, Detroit Fdison requests the incorporation of Curve C to i

Technical Specification 3/4.2.3, Figure 3.2.3-1. Curve C provides the FCPR operating limit assuming operation above 25 percent rated thermal power with both the MSR and the main turbine bypass inoperable. The curve was developed based upon the operating FCPR limits for a.

Feedwater Controller Failure with Inoperable Turbine Bypass transient, his transient is the same as that used to develop Curve B, however, the analysis of the Feedwater Controller Failure transient did not, in this case, take credit for steam flow to the MSR. As a result, the analysis yields a ICPR limit of 1.28 @ T = 0 and 1.35 @ T = 1. ts in the case of the two existing curves, Curve C provides the most limiting transient for the specified bypass condition that results in the largest reduction of CPR. This assures that the fuel c1Mding integrity Safety Limit MCPR of 1.06 is not exceeded during any anticipated abnormal operation transient.

SIGNTFICANP HAZAIDS CONSTDERATION In accordance with 10CER50.92, Detroit niison has mMe a determination that the proposed amendment involves no significant hazards considerations. To make this determination, Detroit a31 son must establish that operation in accordance with the proposed amendnent would not: 1) involve a significant increase in the probability or consequences of an accident previously evaluated, or 2) create the possibility of a new or different kind of accident from any accident previously evaluated, or, 3) involve a significant reduction in a margin of safety.

1) The proposed change clarifying the basis of operation with the Moisture Separator Reheater (MSR) out-of-service does not involve a significant increase in the probability of an mcident previously evaluated as the !CPR Curve B of Figure 3.2.3-1 is still applicable and bounding to this coMition. The MSR is a passive bypass capable of passing a nominal reactor steam flow of 10 percent. We consequences of a Main 'Ibrb!ne Trip with Bypass Failure transient with the MSR inoperable and Feedwater Controller Failure transient with the MSR inoperable result in less severe transients (sraller delta-CPR's) than that of the Feedwater Controller FE.ilure with Inoperable Turbine Bypass. The incorporation of FCPR Curve C of Figure 3.2.3-1 does not involve a significant increase in the probability of an accident previously evaluated as the reduction of CPR'9 specified for the operating scenario of an inoperable main turbine bypass and MSR out-of-service continues to assure that the Safety Limit :CPR of 1.06 is not exceeded. The operating limitations, provided in Curve C, are based upon the consequences of a Feedwater Controller

' ~

% Enclosure to NBC-87-0177 Page 4' Failure with Inoperable Wrbine Bypass transient with no steam flow tnrough the MSR.

2) The proposed change clarifying the basis of operation with MSR out-of-cervice does not create the possibility of a new or different kiM of accident from any accident previously evaluated.

The proposed change only addresses the operating MCPR limits and does not involve any hardware or physical changes to the plant.

The consequences of the Main Turbine Trip with W rbine Bypass Failure and MSR inoperable have been evaluated and 3re bounded by the limits of MCPR Curve B. The consequences of a Feedwater Controller Failure assuming an operable main turbine bypass system and inoperable MSR are less severe because the transient provides approximately 26 percent bypass flow capability while the Feedwater Controller Failure with Inoperable Turbine Bypass transient provides approximately 10 percent bypass flow capability. These events result in a less severe pressure transient than that postulatd for a Feedwater Controller Failure with Inoperable Turbine Bypass. The incorporation of MCPR Curve C of Figure 3.2.3-1 continues to assure that the Safety Limit CPR of 1.06 is not exceeded.

3) The proposed change clarifying the basis of operation with MSR out-of-service does not involve a significant reduction in a margin of safety as detailM in 1) a d 2) above. The Fedwater Controller Failure with Inoperable Turbine Bypass as specified by

!CPR Curve B remains the bounding limit. The incorporation of ICPR Curve C of Figure 3.2.3-1 does not involve a significant reduction in a margin of safety as detailed in 1) aM 2) above.

The Safety Limit MCPR of 1.06 has not been reduced.

ENVIBOLNNIR IMPACT l

Detroit Fdison has reviewed the proposed Technical Specification

changes against the criteria of 10CFR51.22 for environmental I considerations. As shown above, the proposed changes do not involve a significant hazards consideration, nor significantly change the types or significantly increase the amounts of effluents that may be released offsite, nor significantly increase individual or cunulative occupational radiation exposures. Based on the foregoing, Detroit

Edison concludes that the proposed Technical Specifications do meet l

the criteria given in 10CFR51.22(c) (9) for a categorical exclusion from the requirement for an Environmental Impact Statement.

I

~ _ __ _ _

Enclosure to hPC-87-0177 Page 5 Catc w si m Considering the Main Turbine Trip with Turbine Bypass Failure and the Feedwater Controller F111ure transients, the resulting MCPR limits from an operational condition with the MSR inoperable and the main turbine bypass operable would not result in a pressure transient as severe as that postulated for a Feedwater Controller Failure with Inoperable 'Ibrbine Bypass (basis for Curve B) . Thus, these 14'PR limits are bounded by those limits in Curve B. Since Curve B is bounding, clarifying the applicability of Curve B when the MSR is inoperable o_t when the main turbine bypass is inoperable, would allow the plant greater operational flexibility should there ever be a need to perform preventative or corrective naintenance above 25 percent rated thermal power. tdditionally, the incorporation of HCPR Curve C of Figure 3.2.3-1 would allow the operation with an inoperable rain turbine bypass and MSR out-of-service. The limits provided in Curve C are based upon a Feedwater Controller Failure with 'Ibrbine Bypass Failure transient assuming no steam flow through the MSR. The

. proposed scenario of operating with an inoperable main turbine bypass and MSR out-of-service is offset by the restrictions of MCPR limits which assure that the Safety Limit of 1.06 is not exceeded.

Based on the evaluations above: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2)- such activities will be conducted in conpliance with the Commission's regulations and proposed amendments will not be inimical to the comon defense and security or to the health ard safety of the public.

l

"hclosure

.: to hTC-87-0177 Page 6

{

i l

PROPOSED PAGE CHAtGES s

k

>4 4

1 '

i 1

l l

I

)

l l

l l

l

. . .