AECM-86-0129, Application for Amend to License NPF-29,changing Tech Specs Re Max Extended Operating Domain.Amend Required to Support Cycle 1 Operations & Cycle 2 Reload Licensing Effort.Fee Paid

Application for Amend to License NPF-29,changing Tech Specs Re Max Extended Operating Domain.Amend Required to Support Cycle 1 Operations & Cycle 2 Reload Licensing Effort.Fee Paid

ML20197B867
Person / Time
Site:	Grand Gulf
Issue date:	05/02/1986
From:	Kingsley O MISSISSIPPI POWER & LIGHT CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML20197B873	List: AECM-86-0129, Application for Amend to License NPF-29,changing Tech Specs Re Max Extended Operating Domain.Amend Required to Support Cycle 1 Operations & Cycle 2 Reload Licensing Effort.Fee Paid ML20197B884
References
AECM-86-0129, AECM-86-129, TAC-61083, TAC-61357, NUDOCS 8605130172
Download: ML20197B867 (21)

Text

- _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ -

l i

! MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi EdMdhididd5 P. O. B O X 164 0. J AC K S O N. MIS SIS SIP PI 39215-1640 May 2, 1986 O. D. KINGSLEY. J R.

VICE PRESIDENT - NUCLE AR OPE R ATIONS U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D. C. 20555 Attention: Mr. Harold R. Denton, Director

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 File: 0260/0840/L-860.0 Proposed Amendment to the Operating License (PCOL-86/07 ) - Maximum Extended Operating Domain AECM-86/0129 In accordance with the provisions of 10 CFR 50.59 and 50.90, Mississippi Power & Light (MP&L) request an amendment to License NPF-29, for Grand Gulf Nuclear Station (GGNS) Unit 1.

The attached proposed changes to the technical specifications are requested to support GGNS operations in the " Maximum Extended Operating Domain" is defined in the attached documents. .It is MP&L's intent to implement those changes in Cycle 1 concurrent with previously submitted changes associated with core thermal-hydraulic stability and single loop operations (MP&L letter AECM-86/0092, March 31, 1986). MP&L intends to propose similar provisions for fuel Cycle 2. Therefore, to support Cycle 1 operations and the reload licensing effort for Cycle 2, NRC review and approval is requested by July 21, 1986.

In accordance with the provisions of 10 CFR 50.30, three (3) signed originals and forty (40) copies of the requested amendment are enclosed. The attachment provides the complete technical justification and discussion to support the requested amendment. This amendment has been reviewed and accepted by the Plant Safety Review Committee (PSRC) and the Safety Review Committee (SRC).

Based on the guidelines presented in 10 CFR 50.92, it is the opinion of MP&L that this proposed amendment involves no significant hazards considerations. t 8605130172 860502 $

PDR ADOCK 05000416 P PDR cD p flh \

Member Middle South Utilities System J10AECM86050201 - 1 Q W_________________J

4 AECM-86/0129 Page 2 In accordance with the requirements of 10 CFR 170.21, we have determined that the application fee is $150. A remittance of $150 is attached to this letter.

Yours ly, ODK:Im -

/d.

'~

Attachments: GGNS PCOL-86/07 cc: Mr. T. H. Cloninger (w/a)

Mr. R. B. McGehee (w/a)

Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o)

Mr. R. C. Butcher (w/a)

Mr. James M. Taylor, Director (w/a)

Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Dr. J. Nelson Grace, Regional Administrator (w/a)

U. S. Nuclear Regulatory Commission Region II 101 Marietta St., N. W., Suite 2900 Atlanta, Georgia 30323 Dr. Alton B. Cobb (w/a)

State Health Officer State Board of Health Box 1700 Jackson, Mississippi 39205 J10AECM86050201 - 2

~ ,

REMITTANCE ADVICE CHECK DA" a 04/16/86v'*D US NUC REG COMM VENDOR NUMBE R 929958 C "' C *

• 04-012 ort no a % ' ]w a's / DEscuerfloN " , 0jn ,",I," caoss auouwt oiscouNT NET AMOUNT 04 1 63 10CFR170 APPLICATION FEE 04-2616 50 0 50 0 l

l 1  ! I g 1 j l 1 I i i l

I g

i  ; l I I i ' I I

8e ,

i l

I 8 l

i l l

I

! I l 1 l l g I l

' I i l g l

! I i I

I 1 i i I i i

'  ;  ; I I I l g t ] I l l I I  !

l l e

I I I I I l i I DEPOSIT GUAR ANT Y N ATION AL BANK $5543 Jackson, Mississippt 39205 Y MIDDLE SOUTH ENERGY, INC.

P.O. BOX 1640 + JACKSON, MISSISSIPPI 39205 CHECK NO, JOINT ACCOUNT 04-0125 CHECK OATE oog g a ns 9 g, ,, Ct wTs 04 16 86 $150 DO PAY q

TO THE S N WASHINGTON, DC

(, .... ,, '.-

i croER or 20555 ,

hO . l..,-lN '

l ^

s,a~eo e, L J A/ (.. ', ~~

' "~ " " "

eOO E 2 t. & ?n' - :D G 5 30 5 t. 3 Gs: s' 2 3 = 5 9 S a 2 Gn'

BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION LICENSE NO. NPF-29 DOCKET N0. 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY and MIDDLE SOUTH ENERGY, INC.

and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION AFFIRMATION I, 0. D. Kingsley, Jr., being duly sworn, stated that I am Vice

. President, Nuclear Operations of Mississippi Power & Light Company; that on behalf of Mississippi . Power & Light Company, Middle South Energy, Inc., and South Mississippi Electric Power Association I am authorized by Mississippi Power & Light Company to sign and file with the Nuclear Regulatory Commission, this application for amendment of'the Operating License of the Grand Gulf Nuclear Station; that I signed this application as Vice President, Nuclear Operations of Mississippi Power & Light Company; and that the statements made and the matters set forth therein are true and correct to t best of my knowledge, information and belief. , ,

\

~0. D.' Ki n 's '

STATE OF MISSISSIPPI COUNTY OF HINDS i

SUBSCRIBE 0 AND SWORN T0 before me, a Notary Public, in and for the County and State above named, this day of -//, h , 1986.

y (SEAL) x d4 M

(/ Notary Public My ccarnission expires:

My Commhi:1 Cr; ire: Sep. 21, 1937 JI0AECM86050201 - 4

SUBJECT:

NLS-86/06 Technical Specifications 3.2.1, 3.2.2, 3.4.1.1; Tables 2.2.1-1, 3.3.1-1, 4.3.1.1-1, 3.3.4.2-1, 3.3.6-2, and 4.3.6-1; Figures 3.2.1-2, 3.2.1-3 (new). 3.2.3-1 and 3.2.3-2; and Bases 2.2.1, 3/4.2.1, 3/4.2.2, 3/4.2.3, -

3/4.3.4, Table B 3.2.1-1 and Figure B 3/4 2.3-1.

Index pages iv and xii. Affected pages include: iv, xii, 2-4, B2-7, B2-9, 3/4 2-1, 3/4 2-2A, 3/4 2-2b, 3/4 2-3, 3/4 2-5, 3/4 2-6, 3/4 3-5, 3/4 3-8, 3/4 3-43, 3/4 3-55, 3/4 3-57, 3/4 4-1, B3/4 2-1 through 2-7, and B3/4.3-3.

DESCRIPTION OF CHANGES: The required Technical Specification changes to allow GGNS operations in the Maximum Extended Operating Domain (ME00), accommodate rated power operation with reduced feedwater temperatures and to eliminate the APRM trip setdown are as follows:

1. Table 2.2.1-1(2): revise APRM setpoint and allowable value to raise the two loop operation scram lines to higher power setpoints.

2. Bases 2.2.1: delete sentence which refers to Specification 3.2.2. Add sentence defining w, used in APRM flow biased equations.

3. Bases 2.2.1(10 and 11): additional discussion provided concerning the effects of lower feedwtMer temperature on the 40% power turbine stop and control valve closure scram bypass setpoint.

4. Specification 3/4.2.1: incorporate flow dependent and power dependent VAPLHGR reduction factors (new figures 3.2.1-2 and 3.2.1-3).

The Figure 3.2.1-2 proposed (AECM-86/0092) for the single loop operation APLHGR limits has been deleted.

5. Specification 3/4.2.2: eliminate the specification and surveillance requirements related to the setdown of the APRM rod block and scram,setpoints.

6. Figures 3.2.3-1 and 3.2.3-2: Figures 3.2.3-1 and 3.2.3-2 are revised to reflect new MCPR limits.

I 7. Table 3.3.1-1: revise note (h) regarding scram bypass setpoints. Revise ** to complement the new note (h).

l l

l J14 MISC 86020301 - 1

? -- J

8. Table 4.3.1.1-1: delete the last sentence of footnote (d) which refers to Specification 3.2.2.

~

9. Table 3.3.4.2-1: revise note (b) regarding the trip bypass setpoint. Delete

• note which is no longer required.

10. Table 3.3.6-2: increase the two loop operation APRM flow-biased trip setpoint and allowable value and add the high flow clamped trip to the table. Increase recirculation flow trip setpoint and allowable value. Delete the note referring to Specification 3.2.2.

11. Table 4.3.6-1: delete the last sentence of footnote (f) which refers to Specification 3.2.2.

12. Specification 3.4.1.1: delete references to Specification 3.2.2

13. Bases 3/4.2.1: incorporate the MAPLHGR flow -

and power - dependent reduction factors. The reference to Figure 3.2.1-2 proposed for single loop operation has been deleted.

14 Bases 3/4.2.2: eliminate this discussion.

15. Bases Table B 3.2.1-1: revise the initial MCPR value to refer to MCPR f,

16. Bases 3/4.2.3: revise the discussion to incorporate the assumptions and conclusions from the ME0D analysis. Also, editorial and administrative changes are made.

17. Bases Figure B 3/4 2.3-1: revise the operating map to reflect the MEOD.

18. Bases 3/4.2

References:

add reference 7 for the GE ME0D Analysis.

19. Bases 3/4.3.4: add discussion concerning the relation of the 40% power RPT bypass setpoint and feedwater temperature.

20. Index: administrative changes to reflect the deletion of Specification 3.2.2.

l l J14 MISCE 3020301 - 2

DISCUSSION: The purpose of this change request is to propose charges to provide an expanded operating map for GGNS. Alse

- proposed are changes related to the elimination of the APRM setdown (Specification 3.2.2). The changes have been evaluated and found acceptable as discussed below.

Included in the evaluation was the consideration of operation with feedwater heater (s) out of service (FWHOS) with ratea power feedwater temperatures as low as 370 F.

As noted in the attached analysis, this operation does not require any increase in MCPR limit. Operation with feedwater temperatures below 3700 F would require an increase in MCPR limit; this operation is not requested by the proposed changes. The changes proposed here are derived from evaluations of operation

1) in the ME0D

2) with feedwater heaters out of service, and

3) with the elimination of the APRM setdown.

Each of these areas is discussed separately in the attached analysis:

1) ME0D in the first 12 sections of the analysis,

2) FWHOS in the ME00 in Section 13, and

3) APRM setdown elimination with FWH05 in the ME0D in Section 14.

The current power / flow operating domain is described in Section 4.4.3.3 of the FSAR. This operating map was developed based on restrictions such as recirculation pump NPSH, plant control characteristics and core thermal power and flow limits. Safe operation in this region is justified by the accident and transient analyses described in FSAR Chapters 6 and 15. In order to improve the operating flexibility and the capacity factors for GGNS, MP&L contracted General Electric to evaluate the accident and transient scenarios for the modified operating map called the Maximum Extended Operating Domain (ME0D).

The ME0D actually consists of two regions which supplement the current power / flow map. One region expands the map to permit flows up to 105% of rated core flow; this region is termed the increased core flow region (ICFR). The second region, known as the extended load-line region (ELLR),

permits operation at rated power levels with core flows less than 100%.

By expanding the operating domain allowed on the power / flow map, significant benefits can result leading to greater operational flexibility and improved unit capacity factor. From a core operations and fuel management J14 MISC 86020301 - 3

standpoint the chief benefits are: 1) better power shaping and fuel preconditioning, 2) xenon compensation, and 3) compensation for reactivity reduction due to exposure.

The ability to increase power into the ELL region at low core flows allows withdrawal of more control rod notches.

By doing so, the plant can attain, or closely approach, the full power target rod pattern. This allows more opportunity to obtain optimum axial power shapes prior to encountering fuel preconditioning limitations. The net effect of this capability is an improvement in capacity factor through optimized preconditioning ramps and the elimination of subsequent power reductions to attain the target control rod pattern. This additionally provides a fuel performance improvement through the reduction in thermal duty cycling on the fuel-cladding interface.

If the rated load line control rod pattern is maintained as core flew is increased, changing equilibrium xenon concentrations will result in less than rated power at rated core flow. Additional operating room above the rated rod line on the power / flow map allows compensation for power reductions during plant startups due to transient xenon. The gross power reduction due to the reestablishment of equilibrium xenon conditions at rated power have been observed to be as great as 10%-12% during startups with peak xenon and 8%-10% during xenon free startups. Excess flow capability will ensure, subsequent to attainment of equilibrium xenon, the plant would be capable of maintaining rated power.

In order to maintain a high capacity factor, continued operation at rated conditions is necessary. The effects of xenon buildup and' fuel burnup reduce core thermal power and decrease the plant capacity factor. A significant benefit that ME0D offers during rated power operation lies in the fact that rated power conditions can be maintained for a longer period of time without maneuvering rods. This is made possible because rated power can be achieved at less than rated core flow. In the ELLR, 100% power can be achieved at 75% flow. Reactivity changes due to fuel burnup, burnable poison depletion, and increasing xenon inventory can be countered with variations in core flow.

l Increased core flow above 100% is an additional aid provided by the ICFR of the ,ME0D. The ability to stay at full power can be extended by increases in core flow above rated.

The boundaries of the ME0D operating map are:

a) 100% power b) 105% flow c) curve of low power recirculation system jet pump cavitation restriction curves of low core flow based on low speed d) recirculation pump operation and flow control valve position varying from maximum to minimum J14 MISC 86020301 - 4

e) constant rod line which passes through the analyzed minimum flow (75% flow) at 100% power point

- (approximately the 120% rod line).

The attached technical specification changes are proposed to permit operation in the ME0D. In addition, the proposed changes include the elimination of the APRM trip setdown. The setdown requirement has been replaced by more meaningful power and flow dependent MAPLHGR limits, and new MCPR p limits. The new limits reduce the need for manual APRM setpoint adjustment and allow for a more effective direct administration of the fuel thermal limits.

The current GGNS Technical Specifications require that the flow biased scram and rod block setpoints be lowered when the ratio of the Fraction of Rated Power to the Maximum Fraction of Limiting Power Density is less than 1.0. This setdown requirement originated from a now obsolete Minimum Critical Heat Flux Ratio (MCHFR) criterion. The change to the General Electric BWR Thermal Analysis Basis (GETAB),

NED0-10958-A, as a licensing basis and a secondary reliance on flux scram for transient evaluations (for those transients terminated by a scram) now provides a more effective alternative to the setdown requirement. With a revision in the power dependent MCPR limit and new flow and power dependent MAPLHGR limits, it has been demonstrated that operation remains within design and res ilatory limits.

The attached analysis also provides the justification for rated thermgl power operation with feedwater temperatures down to 370 F with no change to the limits and setpoints developed for ME0D and APRM setdown elimination. Indeed, theanalysisaddressesratedthermalpgweroperationwitha feegwatertemperaturereductionof100F(i.e.,downto 320 F). g0peration with rated feedwater temperatures less than 370 F, however, would require additional technical specification changes. MP&L intends to utilize the capabilitytooperatewitharatedfeedwatertempgrature 0

reduction of no more than 50 F (i.e., down to 370 F), which may be accomplished safely within the limits proposed here.

Normalsteadystateragedpoweroperationwithfeedwtter temperatures below '370 F is not proposed by this su%nittal.

Of the changes described above, items 1, 10, 15, 16, 17, and 18 are needed to allow operation in the ME0D. Items 2, 4, 5, 8, 11, 12, 13, 14 and 20 document the replacement of the APRM setdown with power and flow dependent MAPLHGR factors. Item 5 includes a revised flow dependent MCPR based on the ME00 analysis and a revised power dependent J14 MISC 86020301 - 5

MCPR derived from the evaluation of the APRM setdown elimination. Items 3, 7, 9 and 19 are proposed to clarify existing requirements and reflect changes to address opegationwithratedfeedwatertemperaturesaslowas 370 F.

MP&L has already submitted proposed changes to address increased surveillance of core stability and single loop operation (AECM-86/0092, dated March 31,1986). The core stability changes, which consisted of defining a region in which new surveillance requirements would be imposed, apply without further modification to the requirements proposed in this request. That is, operation above the 80% rod line and between 39% and 45% core flow is subject to surveillance and operation above the 80% rod line and less than 39%

flow is restricted. The attached evaluation of MEOD, FWH05 and the APRM setdown elimination presumed the implementation of the core stability detect and suppress recommendations of GE SIL-380, as outlined in the core stability change request (AECM-86/0092).

Single loop operation (SLO), however, has not been analyzed in the ME00. SLO in the ICFR of the ME0D is physically unattainable, but SLO in the ELLR of the ME0D is to be restricted by maintaining the original APRM rod block and scram setpoints, which were based on SLO within the original 105% rod line. The MCPR and MAPLHGR limits developed for ME0D, FWHOS and the APRM setdown elimination are more conservative than those for which SLO was analyzed and thus the limits proposed in this request are applicable to both one and two loop operation. The flow-dependent MAPLHGR reduction factor is clamped for single loop operation flows above 59% core flow in order to limit the factor to its analyzed value (0.86) for SLO.

Similarly, the power-dependent MAPLHGR reduction factor is clamped at the 70% power value for SLO, because SLO is only permitted up to this power level. At 70% power, MAPFAC is 0.845 which is conservatively below the SLO p

factor of 0.86.

MP&L intends to implement the attached proposed changes concurrently with those for core stability / single loop operation. ,

JUSTIFICATION: The proposed changes to the GGNS Technical Specifications are requested following an extensive evaluation of their impact on the safe operation of the plant. The evaluation is described in the GGNS Maximum Extended Operating Domain Analysis, which is provided as an attachment to this submittal. Based on this evaluation it has been concluded that:

J14 MISC 86020301 - 6

1) it is safe to operate the plant in accordance with these specifications, and

2) all reoutrements of 10CFR50 are met.

This evaluation provides justification for these requested changes. The evaluation considered:

a) LOCA analysis - A bounding BWR-6 analysis determined that the current MAPLHGR and MCPR f limits (FSAR Chapter 6) are adequate for the ME00.

b) Containment response - A conservative containment analysis produced a peak drywell pressure of 23.3 psig. This pressure is greater then the drywell pressure determined in the FSAR Chapter 6 analysis but still well below the design pressure of 30 psig.

c) Abnormal Transients - A bounding BWR-6 analysis concluded that the delta-CPR results for all cases analyzed in the MEOD are enveloped by the current MCPRp limits. The MCPR f curve is revised based on the new analysis of the slow recirculation flow runout transient event to accommodate operation in the ICFR. In addition, the following limiting transients were analyzed in detail for GGNS:

1) Generator Load Rejection with Bypass Failure -

As discussed in FSAR Section 15.2.2 this' limiting vessel pressurization transient produced a peak vessel pressure of 1234 psig in the FSAR results. When evaluated for the ME0D, the peak pressure increased only slightly to 1236 psig.

2) Feedwater Flow Controller Failure - Based on the ME0D evaluation, the existing MCPR p operating limits are adequate to ensure this transient will not violate the MCPR safety limit. (MCPR p has been reviged, however, based on the APRM setdown as discussed below.)

3) Asdescribedintheattachedreport,theresufts of the Chapter 15 evaluations of both the 100 F Loss of Feedwater Heater Transient and the Rod Withdrawal Error Transient were found to provide adequate protection in the ME0D.

J14 MISC 86020301 - 7

4) Flow Runout Transient - The evaluation of this transient in the ME0D established the flow-dependent MCPR limits. This event.

analyzed at two flow limiter settings, resulted in MCPR f values which were found to bound other flow dependent abnormal transient events.

d) Stability Evaluation - Based on implementation of GE SIL-380 recommendations as Nguestad in GGNS Operating License Change Request da'.ed 3-31-8b and on the GE generic stability analys1s (NEDE-2227)-P, December, 1982) operation in toe ME0D region complies with the requirements of 10CFR50, Appendix A, GDC 12.

In addition, analyses have been performed which demonstrate that fuel design limits are not exceeded during limit cycle operation.

e) The effects of increased Reactor Internal Pressure Differences, acoustic loads, flow induced loads and fuel bundle lift forces have been evaluated and shown to not cause design limits to be exceeded.

In addition, internal vessel vibrations have been monitored during startup testing which included the ICFR. The test report, which was issued in February, 1986 (AECM-86/0054), supports the analytical conclusions stated above, f) ATWS Evaluation - The ATWS limiting MSIV closure event was analyzed and all significant parameters were found to be within acceptable limits.

g) Overpressure Protection - the MSIV closure transient was analyzed in the ICFR. The peak vessel pressure increased to 1262 psig but this is still well within the design limit of 1375 psig.

The attached ME00 analysis also addresses the elimination of the APPM setdown. The setdown requirement was derived from a now obsolete analytical methodology. The proposed changes incorporate replacement methods for assuring the margin to safety is, maintained.

The impact of the APRM setdown elimination on LOCA and transient analyses results was evaluated. In the case of the LOCA analysis, it was determined that current MAPLHGR limits are adequate. This is based on the fact that the FSAR Chapter 6 LOCA evaluation was performed without taking credit for the setdown. New plant operating limits (MCPR and MAPLHGR) have been developed based on transient evaluations to assure that margins to fuel integrity limits are greater than or equal to those currently in existence.

J14 MISC 86020301 - 8

The revised limits are discussed in Section 15.D.14.3 of the attached GE evaluation. The revised MAPLHGR limits are determined using power and flow dependent multipliers which are applied to the existing two loop operation limits. These factors are always less than or equal to 1.0. Therefore, the governing MAPLHGR limit has not been increased and the above conclusion regarding the LOCA analysis is not affected.

As noted in the DISCUSSION, the changes proposed in this submittal provide limits and setpoints which accommodate normal safe operation in tge ME0D with rated feedwater temperatures as low as 370 F. Justification of this position is provided by a feedwater heater (s) out of service (FWH05) evaluation which is described in Section 15.D.13 of the attached analysis. This evaluation considered:

1) FSAR Chapter 15 abnormal operating transients

2) fuel mechanical design limits

3) LOCA and containment response as described in FSAR Chapter 6

4) fuel integrity thermal-hydraulic stability, and

5) effects of acoustic and flow induced loads The results of this evaluation demonstrate that operation in the MEOD with FWH05 can be accomplished within design and regulatory limits.

A detailed justification for each change is provided below:

1. Table 2.2.1-1: This proposed change increases the flow biased scram setpoint and allowable value by 16%. This change is made to accommodate operation in the ME0D. Opernion in the ME0D was analyzed as described in ti , attached GE report. It was found that operation is this region would not exceed design limits. This proposed change provides access to the extended load line regior, of the ME0D. The revised setpoints maintain the same slope, the same clip setpoint and the same margin between the scram and rod block setpoints as the current technical specifications.

2. Bases 2.2.1: This change to the APRM scram function is an administrative change to delete the reference to Specification 3.2.2. This specification has been proposed for deletion in this change request.

Justification for this deletion is provided below in item 4. Additionally, the definition of the variable w, used in the flow biased equations is provided due to the deletion of Spectification 3.2.2.

J14 MISC 86020301 - 9

3. Bases 2.*c.1: These changes to the turbine stop and control valve closure scrams describe the background for the utilization of two bypass setpoints, dependent on the feedwater temperature.

Justification for the addition is provided in Item 7.

4. Specification 3/4.2.1: As discussed in Section 15.D.14.1 of the attached analysis, a large data base of transient results was used to develop the MAPLHGR reduction factors. The revised limits ensure that equal or increased margin to fuel integrity limits is maintained without the APRM setdown.

The revised limits are presented in the form of yaphs for both a flow dependent and a power dependent MAPFAC (MAPLHGR factor).

The MAPLHGR reduction factors are applicable to one and two loop operation. As noted in the earlier change request for core stability / single loop operation changes, the SLO MAPLHGR reduction factor is 0.86. A MAPFAC clamp is invoked at this value f

for single loop operation. As SLO is not allowed at power levels greater than 70%, MAPFAC p is conservatively clamped at this level for SLO; the resulting MAPFAC p of 0.845 is less than the 0.86 determined in the SLO analysis and is conservative.

5. Specification 3/4.2.2: This specification provided the setdown implementation. As discussed above and in Section 15.D.14 of the attached analysis, the APRM setdown requirement, and thus this specification, are eliminated. The requirement has been replaced by a new power dependent MCPR limit and new MAPLHGR reduction factors to provide a more effective means of assuring that design limits are met.

6. Figures 3.2.3-1 and 2: As a result of the ME00 analyses of the slow recirculation flow runout transient a new flow dependent MCPR limit was established. The proposed curve is slightly greater than the exist'ing curve but is not expected to unduly restrict normal operation.

J14 MISC 86020301 - 10

A new set of power dependent MCPR limits has been devebped based on the evaluation of the elimination of the APRM setdown. The new limits are derived from

- the results of both a GGNS-specific and a bounding BWR/6 analyses. These limits have been generated considering reduced feedwater temperature, and are therefore applicable to operation with feedwater heater (s) out of service.

The operating limit MCPR at any power / flow condition is the larger of the new MCPRfand the MCPRp . The new values are presented in the revised Figures 3.2.3-1 and 3.2.3-2.

7. Table 3.3.1-1: The current technical specifications call for bypassing the turbine stop valve closure and turbine control valve fast closure scrams when thermal power is less than 40% of rated thermal power. The trip unit which performs this automatic bypass function estimates the power-level based on the turbine first stage pressure. Based on startup tesg results, for a rated feedwater temperature of 420 F, 40% of rated power is equivalent to a turbine first stage pressure of 300 psig or 33% of span. The 30% analytical value provided in the current technical specifications is therefore conservative.

The allowable values provided in the proposed specification are based on this conservative analytical limit. In order to account for the change in the relationship between reactor power and turbine first stage pressure with lower feedwater temperatures,thepressurerepresegtativeof40% power

' with feedwater temperatures of 370 F is also presented.

In addition, because the values derived from startup testing is now presented in the note, the existing

(**) note is no longer needed. A new note has been added to provide supplemental infonnation related to this change.

This proposed change, then, clarifies and expands the

• existing requirement. Based on the confirmatory results of Startup Testing, the analytical limit (30%) has been replaced with an allowable setpoint value (26.9% and 22.5%) for each feedwater temperature range.

8. Table 4.3.1.1-1: This is an administrative change to delete reference to specification 3.2.2. With the elimination of the APRM setdown the specification has been eliminated.

J14 MISC 86020301 - 11

9. Table 3.3.4.2-1: The current technical

~

specifications note the end of cycle recirculation pump trip (E0C-RPT) function is automatically bypassed when thermal power is less than 40% of rated thermal power. The change is identical to that made for the TSV/TCV closure scrams (see item 8 above) and the same justification is applicable here.

10. Table 3.3.6-2: In order to accommodate operation in the ME0D, the APRM rod block setpoint has been increased, a high flow clamp has been instituted and the high flow rod block has been increased.

The increase in the APRM flow-biased rod block setpoint is similar to that for the flow-biased simulated thermal power scram justified in item 1 above. The high flow clamp is added to maintain the same clamp setpoint at rated power / flow conditions as is currently available. That is, the maximum setpoint currently available is 108% (at w=100%).

In the ME0D, the new setpoint (which could be calculated to be as high as 128%) is still to be clamped at this value (108%).

In addition, the Recirculation Flow - High rod block setpoint is increased from 108% to 111%. This change addresses an operational concern. Operation in the increased core flow region (ICFR) of the operating map (i.e., with core flow up to 105% of rated) has been evaluated as discussed in the attached GE analysis.

Raising the rod block setpoint will minimize unnecessary rod block alarms when operating in the ICFR. While the allowable flow range has been extended from 100% to 105%, the rod block setpoint has been conservatively raised only 3%. This improves the margin of safety between the allowable flow and the rod block.

11. Table 4.3.6-1: This is an administrative change to delete the reference to Specification 3.2.2. With the elimination of the APRM setdown, Specification 3.2.2 was deleted.

12. Specification 3.4.1.1: same justification as 10 above.

13. Bases 3/4.2.1: This change is complementary to item 4 above. A discussion of the MAPFAC factors is provided to provide the bases for the changes to Specification 3.2.1.

l J14 MISC 86020301 - 12

14. Bases 3/4.2.2: This change, the deletion of the bases discussion, is made because the APRM setdown has been eliminated. The elimination was justified

- in item 4 above and in the introductory section of the JUSTIFICATION.

15. Bases Table 3.2.1-1: The initial MCPR entry in this table has been generalized to refer instead to the flow dependent MCPR f

. This has been done because the analyses for the ME0D addressed two different flow points at 104.2% power. The initial MCPR at each of these points is different, but are both included on the OLMCPR curves as revised in this submittal. The flow dependent curve is referenced here because, as defined by Specification 3.2.3, MCPR f is the operating limit MCPR at both 73.8% flow,104.2% power and the 107% flow, 104.2% power points.

16. Bases 3/4.2.3: A reference has been added to the discussion to identify the source of system parameters utilized in the ME0D analysis. This change expands the bases discussion to cover operation in the MEOD by reference to the GGNS MEOD Analysis.

The new MCPR , curve which is based on an evaluation f

of the flow runout transient to 107% of core flow, is more conservative (i.e., greater in magnitude) than the required MCPR f based on flow runout to 102.5%

core flow. This new MCPRf was also found to bound the required MCPR f for other transients conservatively evaluated in the ELLR at the 104.2% power and 73.8%

flow condition. Therefore, operation below the ME0D power-flow line, which passes through the 100% power, 75% flow point, is bounded by the conclusions of the attached report and can be performed safely within all design and regulatory requirements.

Two references to 102.5% of rated flow are proposed for deletion since two maximum core flow conditions have been analyzed. As noted in the attached report, flow rates up to 107% ficw limiter setting have now been analyzed for GGNS Increased Core Flow operation.

l J14 MISC 86020301 - 13 i

A sentence referring to the APRM setdown has been deleted because the setdown and the specification

- which implemented it have been deleted. For additional information refer to the JUSTIFICATION for Specification 3/4.2.2 above. As a result of the setdown elimination, the MCPR limits have been p

revised. The new MCPR limits are flow dependent at p

core power below 40% of rated thermal power. Below 40% of rated power, the end of cycle-recirculation purp trip and the turbine stop valve closure and turbine control valve fast closure scrams are bypassed. Because of the bypass there is a significant MCPR sensitivity to initial core flows.

At high core flows (i.e., greater than 50% of rated) the MCPR is increased in order to maintain the margin p

of safety.

Also included in the proposed changes are administrative and editorial changes. Specifically:

a) 'MCPR' corrected to 'CPR' (2nd paragraph) -

because the sentence is referring to the change in critical power ratio rather than the minimum, b) deletion of ' minimum' (2nd paragraph) - the use of the description ' minimum' is unnecessary and redundant when referring to MCPR. -

c) deletion of references to Figures 3.2.3-1 and 3.2.3-2 (4th paragraph) - references are unnecessary as the discussion relates to the concepts of MCPR p and MCPR f

rather than the specific values.

d) deletion of second sentence (4th paragraph) the definition of OLMCPR is provided in l

Specification 3.2.1 and need not be repeated here.

e) move thirti sentence into succeeding paragraph (4th paragraph) - this sentence initiates the discussion of MCPR f which is continued in the next paragraph.

17. Bases Figure B 3/4 2.3-1: This figure is revised to reflect the maximum extended operating domain which is justified based on the individual changes described above.

J14 MISC 86020301 - 14

e 4 i

18. Bases 3/4.2

References:

The addition of reference 7 is done to identify the source of the evaluation conclusions upon which the above changes are based.

19. Bases 3/4.3.4: This addition, concerning the turbine stop and control valve closure RPT function bypass at -

40% power is made to describe the need for two feedwater temperature dependent setpoints. This item is justified in item 8 above.

20. Index: These changes are administrative to reflect the deletion of Specification 3.2.2 as justified in item 5 above.

SIGNIFICANT HAZARDS CONSIDERATION:

The changes proposed in this submittal provide for operation in the Maximum Extended Operating Domain (ME0D) and for the elimination of the APRM setdown requirements. All of the proposed changes have been evaluated and found to be appropriateforratedthgrmalpoweroperationwithfeedwater temperatures down to 370 F.

These changes have been evaluated as discussed in the attached analysis. Based on the evaluations the proposed changes do not involve a significant hazards consideration. Details of the basis for this conc.lusion are provided below by addressing the three factors outlined in 10CfR50.92.

1) the changes do not involve a significant increase in the probability or consequences of an accident previously evaluated The changes to support the ME0D satisfy this factor because plant equipment and systems operate within their design limits. Changes to support operation in the ME0D involve a revision of the MCPR and higher limits for the APRM scram and f

rod block setpnints. The increased OLMCPR is needed to maintain the margin of safety in the ICFR as was available in the current operating domain, during the flow runout transient. The revised, limit ensures the consequences of this event are not increased. The revised APRM setpoints maintain the same scram / rod block to power margin in the MEOD as is currently provided. These conclusions are based on the evaluation (see attached report) which considered:

- A bounding BWR/6 LOCA analysis was performed for the ME0D.

It was determined that current MAPLHGR and MCPR p limits J14 MISC 86020301 - 15

and the revised MCPR limits are adequate to ensure LOCA f

consequences are not increased.

- The containment response for a design basis accident in the ME0D and considering a feedwater temperature reduction due to FWH05 is slightly more resere than the analysis provided in FSAR Section 6.2. As presented in the GE analysis, the differential peak drywell pressure of 23.3 psig is 1.3 psi above Chapter 6 value but is still well below the design limit of 30 psig. (This item is 4 considered similar to that of example (vi) of types of changes considered not to involve significant hazards consideration.)

- The ATWS performance evaluation for the ME0D assumed initiation from the 100% power and 75% flow operating point. While this resulted in a higher power condition following the event, pressures remained below the emergency stress limits, and the maximum neutron flux, heat flux, and vessel pressure remained within their respective acceptable limits.

- Fuel thermal and mechanical performance for transients initiated in the ME0D is bounded by the fuel design bases.

- The effects of acoustic, flow induced, and reactor internal pressure differential induced load and of increased flow on the fuel bundle and reactor internals were found to be well within allowable design limits.

The elimination of the APRM setdown involves revised MCPRp and new MAPLHGR reduction factors. These limits are imposed to ensure that margins to fuel integrity limits are equal to or larger than those currently in existence. The criteria by which these changes were judged include:

a) MCPR safety limit shall not be violated, b) fuel performance shall remain within design and licensing bases, and c) PCT and maximum cladding oxidation fractions shall remain within regulatory limits.

Based on these criteria the APRM setdown elimination is judged to meet this factor for significant hazards consideration.

J14 MISC 86020301 - 16

4 As noted in the justification, there are no technical specification changes needed to support rated thermal power

- operationwithafeedwaterheateroutofserviceaslongas feedwater temperatures are at least 370 F. The changes proposed in items 6 and 8 are merely clarifications of the current requirements. Operation under these conditions was evaluated as described in Section 15.D.13 of the attached analysis. The evaluation considered the Chapter 15 transient evaluations, the Chapter 6 LOCA evaluation, fuel mechanical limits and thermal-hydraulic stability and the effects of flow-induced and acoustic loads on the vessel internals. All results remain within design and regulatory limitg. Rated power operation with feedwater temperatures down to 370 F does not involve a significant hazards consideration.

2) the creation of new or different accidents from those previously evaluated -

Operation in the ME0D does not involve any physical plant design changes. It effectively provides for normal plant operation in an increased area of the power-flow operating map. While the events previously analyzed may be initiated from a new operating point, these events were addressed in item 1 above. There are no new or different accidents created by the MEOD related changes.

The elimination of the APRM setdown similarly involves no design changes. With the incorporation of the new MCPR and MAPLHGR limits, plant operation does not change. Therefore, no new or different accident is created by these changes.

Operation with FWHOS again involves normal plant operating practice and no new or different accidents are created in this mode of operation.

3) significant reduction in the margin of safety -

Operation in the ME0D, the APRM setdown elimination and FWHOS have been evaluated. Revised limits and setpoints have been established which maintain or increase the margin of safety provided by the current values. As noted above, the containment response to a DBA initiated from the ME0D with reduced feedwater temperatures resulted in a slightly higher drywell differential pressure than was determined in the FSAR evaluation. However, these changes are not deemed to result in a significant reduction in the margin of safety.

J14 MISC 86020301 - 17

. . __ _. .__