ML19332E670

Rev 1 to Vessel Fatigue Evaluation Considering Revised Thermal Cycles for Quad Cities Nuclear Station,Units 1 & 2

ML19332E670
Person / Time
Site:	Quad Cities
Issue date:	10/26/1989
From:	Caine T, Ranganath S, Stevens G GENERAL ELECTRIC CO.
To:
Shared Package
ML19332E668	List: ML19332E667 ML19332E670
References
SASR-89-02, SASR-89-02-R01, SASR-89-2, SASR-89-2-R1, NUDOCS 8912110088
Download: ML19332E670 (27)

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SASR 89 02 d

DRF 137 0010 October 1989 i

Revision 1 i

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VESSEL FATIGUE EVALUATION CONSIDERING 5

REVISED THERMAL CYCLES i

FOR QUAD CITIES NUCLEAR STATION f

UNITS 1 AND 2

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Prepared by:

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T. A. Caine, Senior Engineer Materials Monitoring &

Structural Analysis Services Verified by:.

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G. L.UStevens, Engineer Materialu Monitoring &

Structurt.1 Analysis Services Reviewed by:

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S. Ranganath Manager Materials Monitoring &

Structural Analysis Services O

GENuclesEnergy 9912110000 891130 PDR ADOCK 05000254 P

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IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT E

PLEASE READ CAREFUL 1Y This report was prepared by the General Electric Company.

The information contained in this report is believed by General Electric to be an accurate and true representation of the facts known, obtained or provided to General Electric at the time this report was prepared.

The. only undertakings of the General Electric Company respecting information in this document 'are contained in the contract governing l

Commonwealth Edison Company Purchase Order No.

32713$ NU 15 and nothing contained in this document shall be construed as changing said contract.

The use of this information except as defined by said contract, or for any purpose other than that for which it is intended, is not authorized; and with respect to any such unauthorized use, neither General Electric Company nor any of the contributors to this docu.sent makes any representation or warranty (express or implied) as to--

the completeness, accuracy or usefulness of the information contained in this document or that such use of such information may not infringe privately owned rights; nor do they assume any responsibility for liability or damage of any kind which may result from such use of such information.

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TABLE OF CONTENTS i-LALL 1.0

SUMMARY

AND RECOMMENDATIONS 11 b

2.0 INTRODUCTION

21

2.1 BACKGROUND

2-1 2.2 REPORT SCOPE 22 3.0 TECHNICAL APPROACH AND ANALYSIS 31 3.1 TECHNICAL APPROACH 31 1

3.2 COMPONENT ANALYSIS FOR SRVB CYCLE DETERMINATION 32 3.2.1 RECIRCULATION INLET 32 3.2.2 SHROUD SUPPORT 33 3.2.3 SUPPORT SKIRT 34 3.2.4 FEEDWATER 34 3.3

SUMMARY

OF SRVB ANALYSIS RESULTS 36 3.4 EVALUATION OF REMAINING COMPONENTS 3-6 3.4.1 RECIRCULATION OUTLET 36 3.4.2 ' CORE SPRAY 37 3.4.3 CRD HYDRAULIC RETURN 37 3.4.4 CRD PENETRATION 38 3.4.5 2" INSTRUMENT N0ZZLE 38 3.4.6 REFUELING CONTAINMENT SKIRT 38 3.4.7 CLOSURE FLANGE REGION 39 3.4.8 VESSEL SHEL13 3 10 4.0 RESULTS 41 L

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5.0 REFERENCES

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1.0

SUMMARY

AND RECOMMENDATIONS This report summarizes the fatigue usage analysis performed for Quad Cities Units 1 and 2 using revised duty cycles.

In addition to the thermal cycles evaluated in Revision 0 of this report, 20 cycles of safety relief valve blowdown (SRVB) have been included in the usage calculations.

This is the largest number of $RVB cycles that can be accommodated without increasing any component fatigue usages above a value of 1.0.

The numbers of cycles analyzed are shown in Table 1 1.

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The analysis results, which are summarized in Table 12, show that the cumulative fatigue usage for the 40 year design life for the revised' duty cycles is less than the allowable value of 1.0 for all components except the closure studs.

The closure studs are replaceable, so the fact that the usage exceeds 1.0 before reaching 40 years does not pose a maj or concern.

The studs are periodically subj ect to visual examination, but a more rigorous inspection is recosamended once the studs are predicted to hava reached a usage of

- 1.0, which is in the year 1990, it is important to note that the studs d2 Int have to be replaced upon reaching a usage of 1.0.

The vessel support skirt, which had a fatigue usage slightly above one (1.07) in the Revision 0 analysis, was reanalyzed with current finite eleinent methods, reducing the 40 year usage to 1.0, even considering 20 cycles of SRVB.

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SUMMARY

OF DESIGN BASIS AND PREDICTED CYCLES i-I UNITS 1 AND 2 UNIT 1 CYCLE UNIT 2 CYCLE NUMBER DESIGN BASIS PREDICTION PREDICTION OF CYCLES l

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CYCLE btstkiPTION AtinVARLE YEAR 40a YEAR 40a ANALY2ED i

Plant Cooldown 119 277 268 278 I

Plant Heatup 120 283 269 296 l

Safety Relief 1

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20 Valve Blowdown Reduction of Power

• 119 50 44 119 for Plant Shutdown Turbine Roll with 120 50 44 120 Feedwater Injection

• Head Spray Injection 119 3

5 119 i

-Loss of Feedwater 80 117 77 117 Heaters Full Loss of Feedwater 80 6

42 80 9

Heaters Partial Loss of Feedwater Flow 80 12 45 80 1

SCRAM 200 281 263 281

. Batch Feedwater 595 0

0 202 Addition During Hot Standby or Plant Cooldown L

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" From Table 1 1 of [5 3), except SRVS cycles are from this report

.b Values can replace design basis cycles for all components but closura studs.

Events not shown are unchanged.

• No more of these cycles are expected, since this mode of shutdown and startup is no longer used.

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2.1 BACKGROUND

The reactor vessel was originally designed for fati ue to a set 5

- of thermal cycles, or design allowables.

The original stress report

[5 1] showed that' the vessel and its components could withstand the designated number of cycles with a fatigue usage factor less than 1.0, as required by the ASME code.

Based on a GE thermal cycle counting procedure [5 2), operating transient cycles through March 1988 were redefined using actual plant data for Units 1 and 2 [5 3).

The method for predicting cycles through 40 years, as recommended in SIL 318

[5 4), resulted in some estimated cycle counts at year 40 that were somewhat higher than the original design basis.

As seen in (5 3),

cycle predictions for the heacup, cooldown, loss of feedwater heaters and SCRAM transients were predicted to exceed the original design basis within 40 years of operation.

Revision 0 of this report recalculated the fatigue usage factors for the vessel and components based on the predicted cycles for 40 years from [5-3), showing usages above 1.0 for the support skirt and the closure studs.

Several developments have made it prudent to revise this report:

A new analysis of the support skirt has been performed [5 5),

showing the fatigue usage for the revised 40 year cycle predictions to be less than 1.0, An estimation of the time for the closure studs to reach a usage of 1.0 was desirable, and A rapid cooldown event, associated with a stuck open relief valve, which is bounded only by the SRVB event, occurred in April 1989 at Unit 1.

This, along with a similar event in 1980, which was inadvertently counted as a cooldown in [5 3), caused the design basis of 1 SRVB cycle to be exceeded.

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• j 2.2 REPORT SCOPE I

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The 40 year cycle predictions from [$ 3) are used to recalculate

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fatigue. usages for the Quad Cities vessel components.

The new

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analysis results for the support skirt are used in place of the original stress analysis.

For several components which have the highest 40 year fatigue usages, the number of SRVB cycles that could be accommodated, keeping usage below 1.0, is determined.

SRVB stresses, which in most cases were not computed in the original stress

report, are determined by scaling stresses for other analyzed I

transients.

For the remaining components, the worst case usage associated with SRVB cycles is conservatively added to the 40 year usage.

Since the fatigue usage of the closure studs is predicted to f

exceed 1.0 before 40 years, the time at which stud usage of 1.0 will be reached is determined.

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3.0 TECHNICAL APPROACH AND ANALYSIS 3.1 TECHNICAL APPROACH The (5 1) stress ' report included a fatigue analysis for the reactor vessel components based on a set of design basis duty cycles.

i In this analysis, fatigue usage factors are recalculated based, in most cases, on methods found in the original stress report, but using the new 40 year cycle predictions as tabulated in (5 3).

This approach results in the original design cycle numbers being applied for all but six transients.

For Heatup, Cooldown, Loss of Feedwater Heaters and SCRAM, ' predicted cycles were increased, based on [5 3)

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results.

Based on input from Commonwealth Edison, the Batch Feedwater Addition During Hot Standby or Plant Cooldown transient is not applicable for operation at Units 1 and 2, so the number of these l

cycles was-reduced. The number of SRVB transients was increased from one cycle to the maximum number possible without exceeding usages of 1.0 in any component (except closure studs, which already exceed 1,0).

l Information from the original stress report was used for all but two components, the feedwater nozzle and the support skirt.

For the feedwater nozzle,. a more recent analysis was available (5 6).

Therefore, the feedwater nozzle reanalysis considered the

[5 6)

report, information-concerning rapid cyclint,,

removal of batch feedwater addition cycles where appropriate, and the inclusion of the additional 40 year transient cycles in arriving at new fatigue usage factors.

For the support skirt, results from the [5 5) fatigue analysis, which are based on the revised 40 year cycles, were used.

Specific calculations of stress and fatigue for the SM.

transirnt were performed for the recirculation inlet nozzle, the shroud support, the support skirt and the _ feedwater nozzle.

These components were selected because of their high fatigue usage factors.

The allowable number of SRVB cycles was detet1 mined from these specific r.aalyses.

For the remaining components, the SRVB fatigue duty was conservatively estimated as being equal to the worst duty of the analyzed components above.

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3.2 COMPONENT ANALYSIS FOR SRVB CYCLE DETERMINATION i

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L Based on the approach outlined in section 3.1, each reactor vessel component considered in (5 1) with a significant predicted usage factor, except for closure studs, was individually analyzed for fatigue usage for the revised duty cycles shown in Table 3 1.

An I

evaluation was then done to estimate the number of SRVB cycles which resulted in a total usage of 1.0.

Closure studs were not considered j

here because the predicted usage exceeds 1.0 without SRVB cycles. The specific details for each component are summarized in individual sections below.

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l 3.2.1 Racirculation Inlet The analysis of this component included separate consideration of a LAS Nozzle, a Type 316 Safe End, and a Type 304 Thermal Sleeve.

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this component, plant heatup/cooldown cycles and improper start were the transients analyzed in [51).

Fatigue usages resulting from the SCRAM and (full) loss of feedwater heater transients were not considered in (5 1).

While the loss of feedwater heater transient cycles - are in fact negligible, the total number of cooldowns and heatups due to SCRAMS associated with the SCRAM and interruption of feedwater flow cycles were included in this reanalysis.

The (5 1) analysis showed very low usage for the safe end and i

nozzle. The single analyzed stress range in [$-1), used to bound all transients was the combination improper start heatup.

New fatigue 1

usage values for both the nozzle and safe end were again L

conservatively calculated by dividing the total number of applicable revised duty cycles from Table 31 by the allowable number of cycles for this transient.

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c,7 The thermal sleeve would have a usage above 1.0 if all cycles were

• 1 umped" under the improper start heatup allowable.

Instead, l

only 10 cycles were counted under thf s transient.

The stresses for cooldown heatup in [5 1] were combined to get a stress range and allowable cycle value for startup shutdown, SCRAM and interruption of i

feedwater flow cycles.

This approach resulted in the 40 year usage, without SRVB cycles, shown in Table 3 2.

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The_SRVB stresses were evaluated by comparison with the improper start ' cooldown.. stresses.

Analysis showed that the improper start f

stresses due to a step change cooldown are more severe than the SRVB i

ramped cooldown case, so the allowable for improper start heatup was used for the SRVB heatup allowable.

The usage per cycle for this stress range and the number of SRVB cycles resulting in a total usage of 1.0 are shown in Table 3 2, 3.2.2 Shroud Suonert The IAS vessel attachment of the shroud support legs was the only I

consideration in the analysis of this component.

For this component, i

the plant heatup/cooldown cycle was the transient evaluated for stress range in (5 1).

In addition, one SRVB cycle was analyzed separately.

Fatigue usages resulting from the SCRAM and (full) loss of feedwater i

heater transients were not considered in [5 1).

While the loss of feedwater heater transient cycles are negligible, the total number of cooldown heatup cycles associated with the SCRAM and interruption of f

feedwater flow cycles were included in this remnalysis.

The stress range associated with SCRAM and interruption of feedwater flow was determined by scaling the range for startup shutdown by the ratio of cooldown temperature differences.

The usage, without SRVB cycles, is shown in Table 3-2.

The additional usage per cycle for the SRVB and the number of cycles at which total usage reaches 1.0 are also shown in Table 3-2.

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0; 3.2.3 Sunnort Skirt I

After Revision 0 of this report showed a usage just over 1.0 for j) the support skirt, an updated analysis was done using current finite element technology [5 5). The heatup cooldown transient was analyzed, just as in the original stress report. Scalig the alternating stress

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of the heatup.cooldown transient by the ratio of temperature differences for the SCRAM and heatup cooldown transients, an L

alternating stress and associated number of allowable cycles for the SCRAM and interruption of feedwater flow transients was calculated.

l The usage for the revised 40 year cycles, reported in [5-5), is shown l

in Table 3 2.

The SRVB was not analyzed in [5 5), but the critical location determined from the finite element analysis is about two inches from the vessel outside surface, or at least 8 inches from the vessel coolant.

Therefore, the rapid cooldown portion of the SRVB transient to 375'F. followed by cooldown at 100*F/hr to 100'F causes no worse stress at the critical location than the normal cooldown transient.

Thus, the SRVB heatup transient is assigned the sanie usage per cycle as ~ the cooldown heatup.

This value, and the number of SRVB cycles required for a total usage of 1.0, are shown in Table 3 2.

3.2.4 Feedvater The analysis'of this component included separate consideration of a LAS.-Nozzle and a Carbon Steel Safe End.

In this case, a more recent analysis was available [5 6) and was therefore utilized.

For this component, 200 plant heatup, 198 plant cooldown, 200 SCRAMS, and 80 (full) loss ' of feedwater heater cycles were among the transients considered in (5 6).

The fatigue tsage effects due to rapid cycling, not included in either (5-1) or [5 6), but available in a report concerning usage resulting from the implementation of the Economic Generation' Control system [5-7), were also included in this analysis.

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From [5 7), the limiting usages due to rapid cycling, assumed

'here to be constant, were.199 for the Nozzle and.322 for the Safe End.

Further, [5 6) considered 2600 Batch Feedwater Additions During l

Hot Standby transients for both the Feedwater Nozzle and the Safe End.

Based on input from Commonwealth Edison, the batch feedwater addition does not occur during hot standby, so the transient is not applicable for operation at Units 1 and 2.

The number of batch feedwater l-addition cycles was reduced (not eliminated) to reflect this.

[

The Feedwater Nozzle-fatigue usage analysis within

[5 6]

consisted of a number of transient combinations.

This analysis isolated the combinations containing the plant heatup, plant cooldown.

SCRAM, and (full) loss of feedwater heater transients and calculated their usage contributions per cycle.

Since these transients, in either a warm up or cooldown form, were each found in a number of combinations, the combination for each that produced the greatest usage.per cycle for each transient was determined.

In this way, the extrapolations to the number of cycles in Table '31 resulted in conservative usages for the nozzle and safe end.

In the analysis presented in (5 6), the calculations for both the Nozzle and the ' Safe End included isolated combinations of batch feedwater -addition cycles.

Removing the usages due to these 2072 cycles with a usage of.3131 for the Nozzle and combinations 2398 cycles with a usage of.4996 for the Safe End - the usage for

-each could be lowered.

While the number of batch feedwater addition cycles was substantially _ reduced, it is important to nota that 202

-such cycles remain in the set of allowables.

Taking into account the information concerning rapid cycling, removal of hot standby cycles, and the incremental usage contributed by the inclusion of the l

additional transient

cycles, new fatigue usage factors were determined, as shown in Table 3 2.

The SRVB transient is less severe than the cooldown associated with the batch feedwater' addition.

The usage per cycle for the batch feedwater addition transient wa's used as a bounding value for the SRVB heatup transient.

The usage per cycle and number of SRVB cycles at which total usage equals 1.0 are shown in Table 3-2.

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l4 3.3

SUMMARY

OF SRVB ANALYSIS RESULTS The results of fatigue analysis including SRVB heatup cycles show that as many as 20 such cycles can be tolerated before any component, other than the closure studs, reaches a 40 year usage of 1.0, Therefore, 20 SRVB cycles and an additional 20 heatup cycles will be considered in each component's fatigue reanalysis.

l.

For the four components already discussed, determination of the I

usage associated with 20 SRVB heatup cycles is done with the numbers i:

in Table 3 2.

For the other components, discussed in Section 3.4, the fatigue is low, so the most limiting SRVB usage per cycle from Table 3 2 is added to the total usage for these components.

3.4 EVALUATION OF REMAININ. COMPONENTS The specific details of the fatigue reanalysis for each of the remaining components are provided in individual sections below.

I l

l 3.4.1 Recirculation Outlet The analysis of this component included separate consideration of a Low Alloy Steel (LAS) Nozzle and a Stainless Steel (SS) Safe End.

For this component, 120 plant heatup/cooldown cycles and 80 SCRAMS were among the transients considered in

[5-1)..

Fatigue usage resulting from the (full) loss of feedwater heater transient was not considered in [$.1) and was assumed to be negligible.

New fatigue usage values for both the Nozzle and Safe End were conservatively calculated by dividing the total number of applicable revised duty cycles from Table 3 1 by the allowable number of cycles representative of the limiting transient event.

Fatigue usage for 20 cycles of SRVB heatup was added as well.

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i o g 3.4.2 Core Serav l

The analysis of this component included separate consideration of

- a 1AS Nozzle and a SS Safe End.

For this component, 120 plant i

heatup/cooldown cycles were among the transients considered in (51).

Fatigue usages resulting from the SCRAM and (full) loss of feedwater 4

heater transients were not considered in [5-1).

While the loss of feedwater heater transient cycles are negligible, the total number of E

SCRAM cycles were also included in this reanalysis. New fatigue usage l

values for both the Nozzle and Safe End were conservatively calculated

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by dividing the total number of applicable revised duty cycles from Table 3 1 by the allowable number of cycles representative of the limiting transient event.

Usage for 20 SRVB heatup cycles was also added.

3.4,3 CRD Hydraulic Return The analysis of this component included separate consideration of a IAS Nozzle and a SS Safe End.

For this component, 120 plant heatup/cooldown cycles and 250 SCRAMS were among the tr nsients considered in (5 1).

Fatigue usage resulting from the (full) loss of feedwater heater transient was not considered in [5 1] and was assumed to be negligible.

New fatigue usage values for both the Nozzle and

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Safe End were conservatively calculated by dividing the total number of applicable revised duty cycles from Table 3 1 by the allowable f

number of cycles representative of the limiting transient event.

Fatigue usage for 20 SRVB cycles was included as well.

The CRD hydraulic return nozzle has not been used for CRD coolant return for some time, and the nozzle is being capped this year.

Therefore, the fatigue results for the nozzle ate conservative.

In fact, the nozzle will probably be exempt from fatigue analysis in the future.

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I 3.4.4 CRD Penetration l

The analysis of this component included separate consideration of t

l SS, IAS, and INCONEL at the penetration.

For this component, a total of 401 cycles representing heatup cooldown and SCRAM were among the l

transients considered in [5 1).

Effects of loss of feedwater heater were not analyzed, but are negligible.

New fatigue usage values for the three materials were conservatively calculated by dividing the l

total number of applicable revised duty cycles from Table 31 by the r-E allowable number of cycles representative of the limiting transient g

event.

SRVB usage was also considered, l

3.4.5 2" Instru==nt Norrie A 1AS Nozzle was the only consideration in the analysis of this component.

For this component, 120 plant heatup/cooldown cycles were among the transients considered in [5 1).

Fatigue usages resulting from the SCRAM and (full) loss of feedwater heater transients were not l

considered in [5 1).

While the loss of feedwater heater transient cycles were assumed to be negligible, the total number of SCRAM cycles were also included in this reanalysis.

A new fatigue usage value for 1

the Nozzle was conservatively calculated by dividing the total number of applicable revised duty cycles from Table 3-1 by the allowable number of cycles representative of the limiting transient event.

Usage for 20 SRVB cycles was also included.

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3.4,6 _Refuelina Containment Skirt l

The IAS Refueling Containment Skirt was the only consideration in the analysis of this component.

For this component, 120 plant heatup/cooldown cycles were the only cycles considered in [5-1).

Fatigue usages resulting from the SCRAM and (full) loss of feedwater 1

heater transients were not considered in [5 1).

While the loss of l

feedwater heater transient cycles were assumed to be negligible, the total number of SCRAM cydles were also included in this reanalysis.

A new fatigue usage value for t'he Refueling Containment Skirt was conservatively calculated by dividing the total number of applicable 38

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0 revised duty _ cycles from Table 31 by the allowable number of cycles representative of the limiting transient event.

SRVB cycles were also included in the fatigue analysis.

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3.4.7 Closure Flanne Rerion The. analysis of this component included separate consideration of a IAS Flange and a IAS Stud.

For this component, 120 plant heatup/cooldown cycles were among the transients considered in [5 11 r.

Fatigue usages resulting from the SCRAM and (full) -loss of feedwater t

l heater transients were not considered in [5 1).

Since different i.

methods are used here for the Flange and Stud, they are discussed

.[

separately.

The Closure Flange analysis in [5 1) considered only the 120 plant heatup/cooldown cycles.

While the loss of feedwater heater transient cycles were assumed to be negligible, the total number of SCRAM cycles were also included in this reanalysis.

A new fatigue usage value for the Closure Flange was conservatively calculated by dividing the total number of applicable revised duty cycles from Tabic 3 1 by the allowable number of cycles representative of the limiting. transient event.

Twenty SRVB cycles were also included in the total usage.

l The analysis of the Stud included 120 plant heatup/cooldown cycles in [5 1] within 12 total transients considered.

However, neitfier SCRAM nor loss of feedwater heaters were included in the analyzed cycles. While the loss of feedwater heater transient cycles we're assumed to be negligible, the total number of SCRAM cycles were included in this reanalysis.

Scaling the alternating stress of the limiting plant heatup/cooldown transient by the ratio of temperature differences for the SCRAM and heatup/cooldown transients, an alternating stress and associated number of allowable cycles for the SCRAM was calculated.

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In determining the stresses for the SRVB transient, which also l

l was not analyzed in-[5 1), the impact on the stud stresses was assumed J

to be the same as a normal cooldown.

This is justified by the facts that the stud is separated from the coolant by a substantial amount of flange metal, and the coolant is steam, rather than water, so heat i

transfer is less effective.

Thus, the rapid cooldown portion of the SRVB would not affect the stud stresses.

-Total usage is the sum of the original usage from [5 1) plus that due to the additional heatup,

cooldown, SCRAM, interruption 'of feedwater flow and SRVB cycles.

Ussge due to SCRAM was determined by dividing the SCRAM and interruption of feedwater flow cycles from Table 31 by the allowable for SCRANs.

Against the heatup/cooldown i

transient allowable, the additional cycles of heatup.cooldown from Table 31 and 20 cycles of SRVB heatup were applied.

3.4,8 Vessel Shells P

The LAS Vessel Shells represented the only consideration in the analysis of this component.

For this component, 120 plant heatup/cooldown cycles were the only cycles considered in [5 1).

Fatigue usages resulting from the SCRAM and (full) loss of feedwater heater transients were not considered in [5 1).

While the loss of feedwater heater transient cycles were assumed to be negligible, the total number of SCRAM cycles were also included in this reanalysis. A new fatigue usage value for the Vessel Shells was conservatively calculated by dividing the total number of applicable revised duty cycles from Table 31 by the allowable number of cycles representative of the limiting transient event.

Usage for 20 SRVB cycles was included as well.

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.w Table 3 1 CYCLES USED TO PREDICT USACE WITHOUT SRVB CYCLES I

UNITS 1 AND 2 UNIT 1 CYCLE UNIT 2 CYCLE NUMBER DESICN BASIS PREDICTION PREDICTION OF CYCLES D

CYCLE DESCRIPTION ATTAVABLE YEAR 40a YEAR 40" ANALY2ED I

Plant Cooldown 119 277 268 278 Plant Heatup 120 278 269 278 j

i Reduction of Power 119 50 44 119

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e for Plant Shutdown j

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Turbine Roll with 120 50 44 120 l

c Feedwater Injection Head Spray Injection 119 3

5 119 Loss of Feedwater 80 117 77 117 Heaters Full' Loss of.Feedwater 80 6

42 80 Heaters Partial Loss of Feedwater Flow 80 12 45 80 SCRAM 200 281 263 281 Batch Feedwater 595 0

0 202 Addition During Hot Standby or Plant Cooldown i-

• From Table 1 1 of Reference [5 3) b Revised Duty Cycles for this' Reanalysis c No more of these cycles are expected, since this mode of shutdown and startup is no longer used.

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/.l1 I MN Table 3 2.

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SUMMARY

OF RESULTS FOR 'SRVB-HEATUP CYCLE FATIGUE i

Total Usage Usage per SRVB Cycles without SRVB Cycle for U-1.0 Comnonent Analyzed-SRVB Cveles (Cvele*1Y (Cveles) 1 s

/\\8 600*1 436

. Recirculation Inlet 0.272 Shroud Support-0.565 950-1 413 I

Feedwater Nozzle 0.530 4000*1 1878

' Support Skirt 0.935 310'1 20 i

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Smallest allowable SRVB cycle value in fourth column becomes design basis number for all components, o

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I Usage for components not listed above:

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4.0 RESULTS i

Utilizing e the methods outlined in section 3.0, vessel fatigue usages were evaluated based on the 40 year cycle predictions provided in L [5 3), including 20 ' cycles of SRVB and 20 additional cycles of I

heatup, as shown in Table 4 1 as " Number of Cycles Analyzed".

The

-usage results based on this set of revised duty cycles is provided as Table 4 2.

i A review of Table 4 2 shows that the fatigue usage values for all components except the closure studs are at or below the limit of 1.0.

The results for the CRD. hydraulic return nozzle, which do not account for' the nozzle-being capped this' year, are conservative.

The fact that the head spray nozzle is also being capped has no effect on the x

results in Table - 4 2, as head spray is not a limiting transient - for any of the. vessel components except the head spray nozzle, 'and that

' nozzle is exempt from fatigue analysis.

Therefore, the analyzed cycles:in Table 41 can be adopted as the revised fatigue design basis cycles for those. components.

Additional analysis has been performed to determine the time at which the closure studs-are predicted to reach a usage of 1.0.

The cycle counting procedure (5 2) included methods for predicting numbers of cycles for. a given year of. operation.

These were used in conjunction with the usage per cycle values for boltup, pressure test and unbolt (one value), for heatup-cooldown and for SCRAM to determine fatigue usage as a function of years of operation. The results, shown I

in Table 4 3, show that both units, should operate about 26 years, or i

to the year 1998, before the stud usage reaches 1.0.

l-l The-analytical nature of the approach used in Table 4-3 gives L

fractions of cycles, which of course is unrealistic as cycles do not l

accumulate in fractional amounts.

There are many combinations of

[

boltup-unbolt, heatup.cooldown, and SCRAM possible.

One such possible 1.

l^

combination is shown at the bottom of Table 4-3.

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Table 4 1

SUMMARY

OF DESICN BASIS AND PREDICTED CYCLES UNITS 1 AND 2 UNIT 1 CYCLE UNIT 2 CYCLE NUMBER DESICN BASIS PREDICTION PREDICTION OF CYCLES b

CYCLE DESCRIPTION AlinWABLE YEAR 40a YEAR 40" ANALYZED 4

b Plant Cooldown 119 277 268 278 Plant Heatup.

120 283 269 298 Safety Relief 1

6-1 20 Valve Blowdown-Reduction of Power" 119 50 44 119 j

for Plant Shutdown

, Turbine Roll with 120 50-44 120 Feedwater Injection

• Head Sprey. Injection 119 3

5 119

' Loss of Feedwater 80 117 77 117 Heaters:

Full-Loss of:Feedwater' 80 6

42 80 Heaters:- Partial Loss of Feedwater Flow 80 12 45 80 SCRAM 200 281 263-281 Batch Feedwater.

595 0

0 202 Addition During Hot Standby'or Plant Cooldown

• From Table 1-ilof (5-3), except SRVB cycles are from this report Values can replace design basis cycles for all L

components'but closure studs.

Events not shown are unchanged.

• No more of these cycles'are expected, since this mode of shutdown and startup is no longer used.

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.Tabte 4-2c CtBFONENT FATIGUE USAGES 38 SED ON REVISE 0 CYCLES,.

(0)

'(C)

(0)

-(E) 1 OELTA USAGE FOR DELTA tfSAEE FOR OELTA USAGE FOR SELTA USAEE FM

-(A+0*C 9*E)

(A) 278 CYCLES OF 201 CYCLES OF~

-117 CYCLES OF:

20 CYCLES OF TOTAL i

CtNFOMENT OLD USfE - ST ARTtP/SIRIT0tRRI SCRAf1 LOSS OF FU NEATER - ' SRV OLOISetAl NEW USadE -

4

..=3 Recirculation Outlet Safe End (SS)*

0.030 0.014

.0.017 0.000 0.065 0.126 Isozzle (LAS)*

0.110' O.050 '

O.064 0.000 0.065 0.209 l

i Recirculation Intet i

Safe End (SS) 0.000 0.000 0.000 0.000 0.033 0.033 Therest 5teeve (SS) 0.220

-0.092 **

.0.144 0.000 0.033 0.306 1

Notzte (LAS) 0.002 0.002

' O.004 0.000 0.033 0.062 l

• Feettsster 4

Sefe End (CS)*

0.480 0.010 0.040 0.000 -

0.005

' O.535 l

Norrte (LAS) 0.382 0.007 0.021 0.001' O.005 0.416 l

Core Sprey Safe End (SS) 0.004 0.002 0.006 0.000 0.065 0.077 Nortte (LAS) 0.013 0.008 0.018 0.000 0.065 0.106 s~

8 CRD Nwdroutic Return Sefe End (SS) 0.007 0.003 0.002 0.000 0.065 0.077 18 o 2 1e (LAS) 0.090 0.030 0.027 0.000 0.065 0.220 l

l CRD Penetration (SS) 0.001 0.000 0.000 0.000 0.065 0.066 (tec0NEL) 0.000 0.000 0.000 0.000 0.065 0.065 i

(LAS) 0.000 0.000 0.000 0.000 0.065 0.065 l

i 2" Instrument mortte (LAS) 0.063 0.027 0.061 0.000 0.065 0.215 Sagsport Skirt (LAS)

~9.935 ***

0.000 0.000 0.000 0.065 1.000 Refuel. Cc62. Skirt (LAS) 0.020 0.026 0.060 0.000 0.065 0.1 71 l

Shroud Sigiport (LAS) 0.340 0.215 0.002 0.000 0.021 0.578 i

l Closure Flange Region l

Ftenge (LAS) 0.006 0.008 0.018 0.000 0.065 0.096 l

Studs (LAS) 0.850

'O.658 0.167 0.000 0.063 1.759 1

Vesset Shetts (LAS) 0.002 0.003 0.006 0.000 0.065 0.075

- SS = Staintess Steet; LAS = Low Attoy Steet; CS = Carbon Steet

- Negative detta usage includes removal of conservatism in originot anstysis

• - Based on revised analysis 15-5), which included att revised cycles except SRVB l

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Table 4-3 USAGE PREDICTION FOR QUAD CITIES CLOSURE STUDS-r

' UNIT 1:

1 STARTUP/

STARTUP/

BOLTUP SHUTDOWN SCRAM BOLTUP SHUTDOWN SCRAM TOTAL-YEAR CYCLES

-CYCLES CYCLES USAGE USAGE USAGE USAGE 16.50 11.00 126.00 135.00 0.03 0.53 0.06 0.68 20.00-

- 13.24 148.68 158.52 0.04 0.62 0.07 0.79 H21.00 13.88 155.16 165.24 0.04 0.65 0.08 0.82 22.00 14.52 161.64, 171.96 0.04 0.67 0.08 0.86 23.00' 15.16 168.12 178.68 0.05.

0.70 0.08 0.89 1

24.00 15.80

'174.60 185.40 0.05 0.73 0.09 0.92 25.00-116.44 181.08 192.12' O.05 0.75 0.09 0.95 j

20.00-17.08:

187.56' 198.84 0.05 0.78 0.09 0.98 27.00 17.72-194.04 205.56 0.05 0.81 0.10 1.02 28.00-118.36 200.52 212.28 0.05 0.84 0.10 1.05 l.s t

L

. UNIT 2:

.STARTUP/

STARTUP/

BOLTUP SHUTDOWN SCRAM BOLTUP SHUTDOWN SCRAM.

TOTAL YEAR-CYCLES CYCLES CYCLES USAGE USAGE USAGE USAGE 16.00 113.00 131.00 140.00 0.04 0.55 0.06 0.71 L

20'00 15.67-154.00 168.00-0.05 0.64 0.08 0.83 121.00:

16.33 159.75 175.00 0.05 0.67 0.08 0.86 22.00 17.00 165.50 182.00 0.05' O.69-0.08 0.88

23.00' 17.67 171'.25 189.00 0.05 0.71 0.09 0.91 24.00 18.33 177.00 196.00' O.05 0.74 0.09 0.94

'25.00' 19.00 182.75~

203.00 0.06 0.76 0.09 0.97

.26.00' 19.67 188.50 210.00 0.06 0.79 0.10 1.00 E

27.00 20.33 194.25 217.00 0.06 0.81 0.10 1.03 28.00 21.00 200.00 224.00 0.06 0.83 0.10 1.06 EXAMPLE:

-2 0. 00 ~

190.00 200.00 0.06 0.79 0.09 1.00

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4 5.0~-REFERENCES f

5-1 Quad' Cities 1 and 2 Stress Report: " Certified Design Document for f

Quad. Cities I & II", B&W Contract No. 610 0122-51/52, GE Order No.- 205-55599. Nuclear Power Generation Division, Babcock &

l

'Wilcox'Co., Mt. Vernon, Indiana, November, 1970.

v.

t 52 Caine, T.

A., " Thermal Cycle Counting Procedure for Dresden Units f

2 and 3-and - Quad Cities Units 1 and 2," GE Report EAS-128-1086, n-July 1987.

r

.. i 5-3 -Caine, T.

A.,

" Tabulation of Thermal Cycles. for Quad Cities n.

Nuclear - Station Units 1 and 2. " GE Report SASR 88 64, October 1988.

- 5 4 "BWR l Reactor. Vessel Cyclic Duty Monitoring," Nuclear Services Information Letter 318, December 1979.

5-5 Papandrea, C; J.,

" Evaluation of Support Skirt Fatigue Usage for Quad Cities Nuclear Station Units 1 and 2," GE Report SASR 89 24,

' March 1989.

i 5-6 "Feedwater' Nozzle Stress Report," GE Report 22A6650 for Dresden l/

Units 2.and 3 and Quad Cities Units 1 and 2, September 1979.

l.

lc~

.5-7: Stevens, G. L. and B. J. Cheek, " Economic Generation and Control

. Fatigue Usage for Dresden Units 2 and 3 and Quad Cities Units 1 and 2," GE Report AE-78-0884, August 1984.

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'"c i AIIACHMERL6 EVALUA110M_0LSIGRIELCANT HAZARDS _CONSIDERAIION r

~

ER0f.QSED CHANGES 'TO FACILITY OPERATING _

l LICERSE_DPR-29 AND DPR-30 DESCRIfl10N OF AMENDMEBLREQUESI An: amendment to-the Quad Cities Unit 1 and 2 Facility Operating

" Licenses is'p'roposed to extend the operating life of Quad Cities Units 1 and 2 p_

.to forty years.

BASIS FOR NO SIGNIFICANT HAZARDS CONSID.ERal10H 1

i L

Commonwealth Ediso'n has evaluated the proposed amendment and

- determined that the= change-involves a no'significant hazards consideration.

In accordance with the criteria of 10 CFR 50.92(C):

1) 1The proposed amendment does not involve a significant increase in the

. probability.or consequences of an accident previously evaluated.

I Quad Cities Units 1-and 2 will continue to be operated within the design

' limits.

The existing inspection and surveillance programs and regulatory

requirements applicable to Units 1 and 2 (discussed in Attachment'4) will

, ensure that the plant systems and components will continue to perform

'their intended function.

This results in the_ continued validity of the assumptions and results of-the Quad Cities Station safety analysis.

-In addition, the proposed license extension will result in a'fofty-year

operating life for Quad Cities Units 1 and 2.

Quad Cities Station was originally designed-for a forty-year operating life.

Station monitoring of plant-thermal cycles has demonstrated that only the closure studs will exceed their. fatigue usage factor in the forty-year period. Consequently, theistuds.will be replaced before'the end of their fatigue-life.

The: extension of Quad Cities Units 1 and 2 operating life-to forty. years will not affect any external phenomena such as the occurrence of an ea'rthquake or'a-tornado.

Thus, the above discussion indicates that the probability of a previously analyzed accident will be unaltered due to the license extension because the overall plant performance is not expected to be altered. Thus, the probability of any accident occurring is unaltered.

The' consequences of any previously evaluated accident will be likewise unaffected.

Since:the plant's system and component operability will be Lpreserved, the applicable safety functions will always be available.

Thus, the consequence of a postulated accident will not be altered from the previous evaluations.

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,2)

The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

As~ discussed above and in Attachment 4, there will be no change in the operating conditions for Quad Cities Units 1 and 2 as a result of the i

-Ilcense extension.

There are no new factors, parameters, or conditions 1

ithat might affect. Quad' Cities Station.

Since the Plant operating.

~ conditions'will-not be altered, then the possibility for a new different kindLof accident could not be created, i

c

3) ;The proposed amendment'does not involve a significant reduction in a-margin.of safety.

r All plant systems and components will continue to function as intended.

.This will be ensured by-the existing inspection and surveillance programs and regulatory. requirements (i.e., 10 CFR 50.49, 50.55a, 50.59 Appendix G.H.etc.)'previously mentioned.

This would include the maintenance of l

all pertinent plant safety functions.

Since all safety functions will continue to be available and since safety system performance will not l

1 degrade, then the margin of safety will not be altered.

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