ML20207J604

From kanterella
Jump to navigation Jump to search

Evaluation of LPCI & Core Spray Sys Pressure Permissive- Plant Hatch Units 1 & 2
ML20207J604
Person / Time
Site: Hatch  Southern Nuclear icon.png
Issue date: 11/30/1985
From: Erbes B, Sozzi G, Stoll C
GENERAL ELECTRIC CO.
To:
Shared Package
ML20207J601 List:
References
DRF-B21-00311, DRF-B21-311, MDE-263-1185, TAC-62029, NUDOCS 8607290186
Download: ML20207J604 (25)
v • d • e


Text

- -_

APPENDIX TO ENCLOSURE 1

. MDE-263-1185 DRF B21-00311 Normber 1985 i

EVALUATION OF LPCI AND CORE SPRAY SYSTEM PRESSURE PERMISSIVE -

PLANT HATCH UNITS 1 &2 i

Prepared by: '

C.H.Stoll, Principal Engineer Application Analysis Services Reviewed by: -

B.J.Erbes. _ Manager Southern Region Licensing Services 1

Approved by: O

) d.L.Sozf;i, $r/ager Application Analysis. Services i

Approved by: N'I /v i < M A.E.Rodra MWanaj;er [

Application Engineering Servicae 8607290186 860718 PDR ADOCK 05000366 PDR l

GENER AL h ELECTRIC MUC:1^Jt ENERCn' B'JE! NESS OPEPATIONS GENERAL ELECTRIC COMPANY

  • 175 CURTNER AVENUE e SAN JOSE, CAUFORNIA 95125

APPENDIX TO ENCL.05URE 1 (Continued) MDE-263-1185 IMPORTANT NOTICE REGARDING ,

CONTENTS OF THIS REPORT Please read carefully The only undertakings of General Electric Company respecting infor-mation in this document are contained in the contract between the customer and General Electric Company, as identified in the pur-chase order for this report and nothing contained in this document shall be construe'd as changing the contract. The use of this infor-mation by anyone other than the custosier or for any purpose other than that for which it was intended, is not authorized; and mith respect to any unauthorized use, General Electric Company makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document.

i e

l

)

i

(

APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185 TABLE OF CONTENTS ,

1. INTRODUCTION ................................................ 1

1.1 BACKGROUND

.............................................. 1 1.2 PURPOSE ................................................. 2

2. EVALUATION OF OPERATING LIMITS .............................. 3 2.1 FUEL THERMAL LIMITS ..................................... 3 2.2 EQUIPMENT OPERATING LIMITS .............................. 3 2.3 LOCA LIMITS ............................................. 3
3. EVALUATION OF IMPACT ON LOCA PERFORMANCE .................... 5 3.1 SINGLE FAILURE EVALUATION ............................... 5 3.2 LOCA SCENARIOS POTENTIALLY AFFECTED ..................... 6
4. ECCS PERFORMANCE ANALYSIS ................................... 8 4.1 LIMITING LARGE BREAK LOCAs .............................. 8 4.2 OTHER LARGE BREAK LOCAs ................................. 9 4.3 SMALL BREAK LOCAs ....................................... 10 4.4 INTERMEDIATE SIZED LOCAs ................,............... 11
5. SEMMARY AND CONCLUSIONS ..................................... 12
6. TABLE 1-PERTINENT FAILURE & BREAK COMBINATIONS .............. 13
7. FIGURE 1 - Hatch Unit 1 Limiting LOCA Pressure Time History . 14
8. FIGURE 2 - Hatch Unit 2 Limiting LOCA Pressure Time History . 15
9. FIGURE 3 - Hatch Suction DBA Pressure Time History .......... 16
10. FIGURE 4 - Hatch Small Break Pressure Time History ......... 17
11. FIGURE 5 - Hatch Intermediate Break Pressure Time History .. 18 L _ __. . _ _ _ _ _ __ . - - _ _ . . _

APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185 ABSTRACT An evaluation has been performed to deterweine the potential impact of lowering the lower bound injection-valve-pressure-permissive setpoint for the low pressure core spray system (LPCS) and the low pressure coolant injection system (LPCI) at Plant Hatch Units 1 &

2. The results indicate that the lower bound technical specifica-tion limit for this pressure permissive setpoint may bo lowered by 75 psi to 350 psia. The Lnpact of this change on the peak cladding temperatures (PCTs ) is negligible. Therefore the plant operating limits do not require any changes for operating with this setpoint reduced. The impact on the safety of the plant for this amount of change is judged to be negligible.

- -111-

APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185

1. INTRODUCTION .

1.1 BACKGROUND

The current technical specifications for Plant Hatch Units 1 & 2 state that the LPCI system and the LPCS system injection-valve-pressure -permissive setpoint should have a maximum value of 500 psia vessel pressure and a minimum value of 425 psia vessel pres-sure. The purpose of the pressure permissive is to avoid opening the valves prematurely at high vessel pressure before the vessel has depressurized to near the operating range of the low pressure ECCS.13oth the LPCS and the LPCI system injection lines are also equipped with check valves between the low pressure pumps and the reactor vessel to prevent potential overpressure of the low pres-sure piping even if the injection valves were to be opened prema-turely.

The primary consideration governing the lower limit of the pressure permissive setpoint (which is proposed to be changed ) is to ensure that the injection valves will open soon enough during a postulated loss of coolant accident ( LOCA ) to allow tLuely coolant injection to the reactor vessel.

A significant range exists between the lower limit and upper limit

  • LPCI means the low pressure coolant injection mode of the RHR system which utilizes all four RHR pumps to inject water from the suppression pool to the reactor vessel. LPCS means either or both of the two low pressure core spray systems which are designed to inject water from the suppression pool to the reactor core.

- - . . - . . . . , - - . . . . . . . _ _ . - . . ~ . _ . - - . , , - . . , . - , . . _ - - , - . _ . - . . - , . - - -

f APPENDIX TO ENCLOSURE 1 (Continued) f1DE-263-1185

)

values that isill satisfy these design basis requirements for this ,

setpoint. The upper limit was historically established based on the l

piping design of the LPCI and LPCS systems and the lower limit was set as high as practical allowing a reasonable margin beloos the upper limit for instrument accuracy and potential instrument drift.

The minimum allowable value that will conform with current licens-ing analysis will be investigated in this evaluation.

1.2 PURPOSE The purpose of this report is to present the results of an evalua-tion performed for the Plant Hatch Units 1 & 2 to determine the impact (if any ) on plant operating limits due to a proposed change to the lower bound limit of the low pressure ECCS injection-valve-permissive setpoint from 425 psia to 350 psia.

l APPENDIX TO ENCLOSURE 1 (Continued) 1DE-263-1185

2. EVALUATION OF OPERATING LIMITS .

2.1 FUEL THERMAL LIMITS The transients governing fuel thermal ILnits occur at relatively high vessel pressure. Since the LPCI and LPCS cannot inject water into the reactor vessel until the reactor is depressurized, the fuel thermal limits are not impacted by the performance of these low pressure ECCS systems. Therefore the proposed change in the permissive setpoint has no bmpact on fuel thenmal limits.

2.2 EQUIPMENT OPERATING LIMITS The purpose of the subject pressure permissive is to avoid opening the low pressure ECCS injection valves prematurely at high reactor pressure before the vessel has depressurized to near the operating pressure of these systems. Since the upper limit in the technical specifications for this setpoint is not proposed to be changed, l

there is no increase in the potential for premature opening of the injection valves. Therefore there is no Lnpact on equipment operat-ing lLnits due to the proposed change.

2.3 LOCA LIMITS The core MAPLHGR limits are determined by analyses of postulated LOCAs to ensure compliance with 10CFR50.46 and Appendix K to 10CFR50. The limiting scenarios for these analyses involve the operation of the low pressure ECCS. Therefore the proposed change

4 APPENDIX TO ENCLOSURE 1 (Continued) 11DE-263-1185 in persaissive setpoint could potentially have an impact on LOCA, lisaits.

es em

[

APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185

3. ' EVALUATION OF IMPACT ON LOCA PERFORMANCE .

Based on the above evaluation of operating limits, the proposed change in permissive setpoint has a potential impact only on LOCA MAPLHGR limits and on maximum PCT in the core during postulated LOCAs. Therefore, the LOCA analysis was re-evaluated to determine the potential Lnpact on these parameters.

First, the potential single failures during postulated LOCAs were evaluated to determine which LOCA scenarios could be affected by the proposed change. Next the effect on the ECCS performance for the pertinent LOCA scenarios were evaluated.

3.1 SINGLE FAILURE EVALUATION The limiting single failure for the limiting large break LOCA for Plant Hatch Units 1 & 2 is the failure of the LPCI Injection valve to open. Other relevant single failures considered for large break LOCA analysis include a failure of one of the emergency diesel I generators resulting in the loss of function of more than one j l

emergency core cooling system. The pertinent single failures and .

the systems that continue to inject water into the vessel after the .

I postulated break and single failure are summarized in Table 1 for Plant Hatch Units 1 & 2.

l t

(

l The calculated PCT for the failure of one of the emergency diesels (which results in at least one LPCI injecting to the vessel) is substantially less than the PCT for the LPCI injection valve failure which results in no LPCI injection. Furthenmore, the i i

APPENDIX TO ENCLUSURE 1 (Continued) MDE-263-1185 licensing analysis ,

for Plant Hatch Units 1 & 2 assumes no credit ,

for any LPCI flow into the vessel until the discharge valve in the unbroken recirculation loop has completely closed preventing any LPCI back-flow through the recirculation pump into the down-comer region of the vessel. The pressure permissive on the closure of the recirculation discharge valve is set at approximately 300 psia (much lower than the LPCI injection valve permissive) and the valve stroke time is nominally 30 seconds (longer than the LPCI injection I

valve stroke time of approximately 24 seconds). Therefore the limiting time delay assumed for LPCI injection is based on the time j to close the recirculation discharge valve and is not sensitive to changes in the time the LPCI injection valve begins to open. The time of LPCI injection valve opening would have to change by a very large amount (approximately 20 seconds increase) before the licens-ing analysis would be affected.

Based on the above evaluation, the only potential effect that the proposed change in setpoint could have on the licensing analysis of the plants is an effect on the time of core spray injection.

3.2 LOCA SCENARIOS POTENTIALLY AFFECTED From the above evaluations the only LOCA scenarios that could be affected by the proposed change in setpoint are the scenarios where the primary core cooling is from the core spray systems and the potential for impact is greatest where the depresourization rate is rapid ( i.e. for large breaks). Since the limiting LOCA scenario for Plant Hatch Units 1 & 2 is based on cooling the core with the two

APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185 core spray systems for a large break as shown in Table 1, a change, in the time of core spray injection could potentially affect the limiting calculated PCT. Therefore the impa:.t of the proposed change on this LOCA scenario is the limiting impact. This fact is further substantiated by the evaluations for large, small, and intermediate sized LOCAs given below.

6

[

APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185

4. ECCS PERFORMANCE ANALYSIS The potential impact of the proposed change in setpoint on the core spray system performance in to slightly delay the time of injection into the vessel. The core spray injection valves for Plant Hatch Units 1 & 2 have an injection valve stroke time of 11 seconds maximum. The vessel pressure at incipient core spray injection flow is approximately 310 psia for the core spray systems of Plant Hatch Unita 1 & 2. However, a conservative value of 279 psia is assumed in the licensing analysis previously performed by GE and in this evaluation.

4.1 LIMITING LARGE BREAK LOCAs The limiting LOCA scenarios for Plant Hatch Units 1 & 2 were re-analyzed with the GE licensing evaluation models SAFE and REFLOOD.

The pressure time history for the limiting breaks are shown in Figures 1 & 2 for Units 1-& 2 respectively. For Plant Hatch Unit 1 the current pressure permissive of 425 psia is reached at 36 seconds and the the core spray flow begins to enter the vessel at injection valve (which is a gate 42 seconds. In this case the valve) is approximately 54% open by the time spray flow first I

starts entering the vessel ( at approximately 8% of rated flow ) and is 100% open before the time rated flow is achieved.

For Plant Hatch Unit 2 the pressure permissive of 425 paia is reached at 34 seconds and the spray flow starts entering the vessel at 39 seconds. In this case the injection valve is 45% of the way

_a_

_ _ _ _ _ _ . _ . ~ . _ _ _ _ _ _ - - _ _ - , _ _ - - _ _ _ . _ . . _ _ _ _ _ _ . _ . _ _ _ , _ _ _ _ _ . _ _ . _ _ _ _ . _ _ - . _ , . _ . _ _ _ - . _ _ _ _ _

l

{~

APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185 open by the tLme the spray flow first starts entering the vessel, and is approximately 100% open before the time rated flow is achieved.

If the pressure permissive were changed to 350 psia, the time at which the injection valves would start to open would be only ap-proximately 3 seconds later. The valves would be greater than 25%

open for both Plant Hatch Unit 1 and Unit 2 by the time spray flow

( approx imately 8% of rated ) started entering the vessel and would still be 100% open by the time rated pressure for the core spray system is achieved. The loss coefficient for flow through a gate valve becomes relatively negligible by the time the valve is 50%

open and the flow rate of the system is maall until vessel pressure approaches the system rated pressure. Therefore a reduction in the injection valve pressure permissive to 350 psia would not sig-nificantly affect the performance of the core spray system for the 1Luiting large break LOCA.

(

4.2 OTHER LARGE BREAK LOCAs i Other postulated large break scenarios that are not limiting for Plant Hatch Units 1 & 2, but involve even larger break sizes and therefore more rapid depressurization, are the recirculation suc-tion line breaks. The largest liquid break with the most rapid depressurization is the guillotine fracture of the recirculation auction line. The depressurization rate of this LOCA was also

evaluated for completeness for Plant Hatch Unit 1 and the pressure time history is shown in Figure 3.

_ 9_

l APPENDIX TO ENCLOSURE 1 (Continued) MDE-263-1185 For this break the current pressure permissive of 425 psia is ,,

reached at approximately 18 seconds and the core spray injection valve is 100% open by the time the core spray system is assumed to inject into the vessel in licensing analysis. If the pressure pennissive were changed to 350 psia the tLue the injection valves would start opening is only delayed by approximately 2 seconds compared with a 425 psia setpoint and the valve is still 100% open by the time spray flow commences. Therefore even for the largest liquid break with the most rapid depressurization a change in i

permissive setpoint to 350 psia would have no impact on ECCS per-I fonmance.

4.3 SMALL BREAK LOCAs Small break LOCAs ( breaks approximately 0.1 sq ft and maaller) are not large enough to depressurize the reactor in the short term. For a maall break LOCA with the most limiting single failure (a failure of the HPCI sys tem ) the ADS will automatically depressurize the vessel to the operating pressure of the LPCS and the LPCI. The depressurization rate is primarily a function of the ADS capacity and therefore will not vary significantly for breaks from 0.0 to approximately 0.15 sq ft. Analysis of a 0.1 sq f t recirculation line break assuming the most limiting single failure for small breaks ( the failure of the HPCI ) was performed for Plant Hatch Unit 1 with the GE licensing evaluation model SAFE. The pressure time history is shown in Figure 4. In this case the vessel pressure reaches the current injection valve permissive setpoint of 425 psia

_ _ _ _ _ _ _ . ~ . . . _ _ . _ _ _ _ _ _ . . _ _ . _

I APPENDIX TO ENCLOSURE I (Continued) MDE-263-1185 at 275 seconds and the injection valves are 100% open long before the tLae spray flow commences at approximately 309 seconds. If the permissive setpoint were changed to 350 psia the injection valves for either LPCI or LPCS would still be 100% open by the time system flow commences. Therefore a change in the pressure pennissive to 350 psia would have no Lnpact at all on ECCS performance for small break LOCAs.

4.4 INTERMEDIATE SIZED LOCAs 0.8 sq ft was An intermediate sized recirculation line break of also analyzed with the GE licensing evaluation model SAFE. The l

vessel pressure time history for this case is shown in Figure 5. In this case the vessel pressure reaches the current pennissive set-point of 425 psia at approximately 73 seconds and the core spray injection valve is 72% open by the time spray flow commences (at 8%

of rated flow) and the valve is 100% open before the rated pressure of the core spray system is reached. If the permissive setpoint Mere changed to 350 psia the time the injection valve would start l

opening would be delayed by approximately 4 seconds. However the valve would be 36% open by the time spray flow commences and would still be 100% open by the time rated core spray system pressure and flow are achieved. Therefore a change in pennissive setpoint to 350 l

significant affect on intermediate sized psia would not have a LOCAs.

APPENDIX TO ENCLOSURE 1 MDE-263-1185 (Continued)

5.

SUMMARY

AND CONCLUSIONS ,

Based on the above evaluations a setpoint as low as 350 psia for the LPCS and LPCI pressure permissive is within the plant design basis and safety analysis assumptions and may therefore be imple-mented without any changes to operating limits or licensing )

analysis. Any value lower than this would require more detailed re-evaluation to determine the potential Lapact on operating limits.

O 6

/

f APPENDIX TO ENCLOSURE 1 MDE-263-1185 (Continued)

6. TABLE 1-PERTINENT FAILURE & BREAK COMBINATIONS HATCH UNITS 1 & 2 PLANT FAILURE BREAK SYSTEMS INJECTING TO VESSEL HATCH 1 LPCI Inj. Valve LARGE DISCHARGE 2 LPCS + HPCI

i

  • LIMITING SINGLE FAILURE & BREAK COMBINATION m

39 85 c.x E8 3

5

HATCH 1-80% DSCG DBA Depressurization (Magnified Scale) j m

jg 450 a i

I z 400 -

a.

r i

m 350 -

O @p.

'E a

,S SPRAY STARTS 300 - @

W m l E r- e 3 10 E e i h 250 - E Y e E  :

E a g g;j 200 -

a g M n

$ 150 - SPRAY RATED

a 100 -

=

L 4 l 50 i , i i i i i E

35 45 55 65 75 e z

TIME AFTER SCRAM (sec) 7 o

a

i 29 85 c.*

,i

=s i E 8. m

! HATCH 2-86.5% DSCG DBA Depressurization ~!5 i (Magnified Scale) M O

, 450- E i i m

~

x

400 -  %

i

' o.

r m 350 - E a e y O 300 -

w [ , Es r a

., ci Y

' m r w y 250 - g 1

. e n -a a R g P

l d

in 200 -

8 j IA >

150 - SPRAY RATED y I

I e

e

! e 1

100 - 5 a

50 30 40 50 SO

, ,o 70 f

TIME AFTER SCRAM (sec) a e

i O t 1 1

) _ __ _ _ _ _ __. ___ . _ _ _ _ _ _ _ . _ _ _ . _ _

I

, , m m

95 ER

.  ;~

I 8

HATCH -100% SUCT DBA Depressurization ,,

35 (Spray on at Roted Flow) o 8 i

450 g g m m J

~

400 - W i

c 4

350 - m

^ Ei 1

$a 300 -

7 m a v c e w .

o m i l E " 8

a a 250 -
  • N l
  • M 0 $

I M g

! W e 4

E 200 - e .*

G- > a

.a UI w 1 m 150 - e is IC i

100 - SPRAY STARTS

! o

! 4 50 - E i

o =

1 O i e i i e i i i i a I 15 25 35 45 55 65 o j TIME AFTER SCRAM (sec) 1 i

m m" 98 ER

p l HATCH - 0.1 Sq Ft SUCT Depressurization , 35 (ADS Depressurization) .-.

S 440 Q. g 420 - $ [

400 -

  • l 380 -

I E

l m 360 - $

O

- 'E 340 - b ,

320 - E, SPRAY STARTS I.

1 300 - [ @

s $.

' y 280 - y Y f k 260 -  !

w

[;j 240 -

l m m 220 - e

$ 200 -

m 4

,E 180 - .

s l

l 160 -

f.

140 -

s 120 , , , , , , , , r 270 290 310 330 350 $

o j TIME AFTER SCRAM (sec) E l

l

J l 4

. A

! 95 i a;:

n 1

m 5 l HATCH -0.8 Sq Ft SUCT Depressurization 5 35o

o l 450 * $

i i G~

1 - .

400 - g l
  • a.

o 350 - :r 1 a m

~

D :s n

300 - SPRAY STARTS e a e z O

14 . m E

, 1 3 250 - [

r g' et to M a to 1

W e .ia E e

n. 200 -

e a a 9 G

! w e l Q 150 - SPRAY RATED E 1

y ,

9 100 - e u

l c I 50 - e 1 -

= 3 j

O , , , , , , , e j 70 90 110 130 150 m r

i TIME AFTER SCRAM (sec) i O

9

! M t

I 1 .

I i

/

Georgia Power4Lh ENCLOSURE 2 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNIT 2 REQUEST TO REVISE SETPOINTS FOR CERTAIN ANALOG TRANSMIIIER TRIP SYSTEM INSTRUMENTS 10 CFR 50.92 EVALUATION Pursuantamendment proposed to 10 CFR 50.92, Georgia Power Company has evaluated the attached for Plant adoption would not involve Hatch Unit a significant 2 and consideration.

hazards has determined that its for this determination is as follows: The basis Proposed Change 1:

This proposed change would revise Technical Specifications allowable values for certain Barton, ATTS instruments to allow for the use of Rosemount, as well as transmitters.

I Basis This change' does not involve a significant increase in the probability or consequences of an accident, because the proposed allowable values are calculated using NRC-approved to the analytical limits. methodology and preserve appropriate margins The possibility of a different kind of accident from any analyzed previously is not created by this change, because the trip function, as described in the FSAR, is not changed.

Margins of safety are not significantly reduced by this change, because the proposed allowable values are calculated using NRC-app:oved methodology and preserve appropriate margins to the analytical limits.

Proposed Change 2:

This proposed change would provide administrative corrections to Technical Specifications pertainingclarifications to the and ATTS instrumentation.

I E2-1 0622C 07/18/86 nwns

GeorgiaPowerkh ENCLOSURE 2 (Continued)

NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. HATCH NUCLEAR PLANT. UNIT 2 REQUEST TO REVISE SETPOINTS FOR CERTAIN ANALOG TRANSMITTER TRIP SYSTEM INSTRUMENTS 10 CFR 50.92 EVALUATION Basis:

This proposed change corrects inaccurate descriptive information and also adds descriptive information. No changes to plant operation will result from this change.

This change does not involve a significant increase in the probability or consequences of an accident, because it is administrative in nature.

The possibility of a different kind of accident from any analyzed previously is not created by this change, because plant design and operation are not affected.

Margins of safety are not significantly reduced by this change, because the plant safety analyses are not affected.

This change is consistent with Item (i) of the " Examples of Amendments that are Considered Not Likely to Involve Significant Hazards Considerations,"

listed on page 14,870 of the Federal Register, April 6,1983. The proposed editorial change corrects errors and adds clarification to the Technical Specifications and, therefore, meets the requirements of Item (i) for an amendment involving no significant hazards considerations.

Proposed Change 3:

This proposed change would revise the Technical Specifications allowable value for instrumentation which provides the high drywell pressure trip function.

Basis This change does not involve a significant increase in the probability or consequences of an accident, because the proposed allowable value is calculated using NRC-approved methodology and preserves appropriate margins to the analytical limits.

E2-2 0622C 07/18/86

GeorgiaPower d ENCLOSURE 2 (Continued)

NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNIT 2 REQUEST TO REVISE SETPOINTS FOR CERTAIN ANALOG TRANSMITTER TRIP SYSTEM INSTRUMENTS 10 CFR 50.92 EVALUATION The possibility of a different kind of accident from any analyzed previously is not created by this change, because the trip function, as described in the FSAR, is not changed.

Margins of safety are not significantly reduced by this change, because the proposed allowable value is calculated using NRC-approved methodology and preserves appropriate margins to the analytical limits.

Proposed Change 4:

This proposed change would revise the Technical Specifications allowable value for instrumentation which provides the permissive to open the RHR-LPCI and core spray injection valves upon decreasing reactor pressure.

Basis This change does not involve a significant increase in the probability or consequences of an accident, because the proposed allowable value is based upon a new analytical limit which has been shown to be within the plant design basis and safety analysis assumptions.

The possibility of a different kind of accident from any analyzed previously is not created by this change, because the equipment function, as described in the FSAR, is not changed.

Margins of safety are not significantly reduced by this change, because the ,

proposed allowable value preserves appropriate margins to the new analytical j limit.

E2-3 0622C 07/18/86

- _ . _ d

Retrieved from "https://kanterella.com/w/index.php?title=ML20207J604&oldid=3320184"