ML20235A827
| ML20235A827 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 09/18/1987 |
| From: | Schnell D UNION ELECTRIC CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| ULNRC-1618, NUDOCS 8709230432 | |
| Download: ML20235A827 (16) | |
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Union l* Etscraic 143 1901 Gratiot Street. St. Louis Donald F. Schnell September 18, 1987 Vice President U.S. Nuclear Regulatory Commission
' ATTN:
Document Control Desk Washington, DC 20555 Gentlemen:
ULNRC-1618 DOCKET NUMBER 50-483 CALLAWAY PLANT i
RESPONSES TO QUESTIONS ON
__CALLAWAY PLANT UPRATING
References:
1)
ULNRC-1471 dated March 31, 1987
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2)
ULNRC-1494 dated April 21, 1987 3)
NRC letter dated August 5, 1987 from T. W. Alexion to D.
F.
Schnell 4)
ULNRC-1470 dated March 31, 1987 5)
ULNRC-1535 dated June 18, 1987 References 1 and -2 transmitted the license application and additional supporting information for the Callaway plant uprating.
Attached to this letter are responses to your request for additional information transmitted by Reference 3.
Reference 4 transmitted the reload license application for Callaway Cycle 3.
In Reference 5, a revision to the Technical Specifications dealing with 4T and the associated bases were o
transmitted.
With approval of these changes in the Callaway Cycle 3 amendment, there will be no changes necessary for the specification on AT, for the Callaway uprating.-
Therefore, please disregard the changes requested on pages 2-7 and 2-9 which were contained in Attachment 2 of Reference 1.
If there are any further questions, please contact us.
Very truly yours, M
/
1 Donald F. Schnell KGC/ mat Attachment
, d5 gr RBen 88$33
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Alaihng Address: P.O. Box 149. St. Louts MO 631(i6
STATb OF MISSOURI )
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Robert J.
Schukai, of lawful age, being first duly sworn upon oath says that he is General Manager-Engineering (Nuclear) for Union Electric Company; that he has read the foregoing document and I
knows the content thereof; that he has executed the same for and on behalf of said company with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.
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By Robert 2 7 6hukai Gener anager-Engineering Nuclear SUBSCRIBED and sworn to before me this /
day of
/a< / 1987 l
PFAFk BAR6 ARA N01 ARY PUBUC, stair OF MISSOURI MY COMMISSION EXPIRES APRIL 22,192 ST. LOUIS COUNTY.
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cc:
Gerald Charnoff, Esq.
Shaw, Pittman, Potts & Trowbridge 2300 N.
- Street, N.W.
Washington, D.C.
20037 Dr. J. O. Cermak CFA, Inc.
4 Professional Drive (Suite 110)
Gaithersburg, MD 20879 W.
L.
Forney-Chief, Reactor Project Branch 1 U.S.
Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137 Bruce Little Callaway Resident Office U.S.
Nuclear Regulatory Commission i
RR51 l
l Steedman, Missouri 65077 l
Tom Alexion (2)
Office of Nuclear Reactor Regulation l
U.S.
Nuclear Regulatory Commission l
Mail Stop 316 7920 Norfolk Avenue Bethesda, MD 20014
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Ron Kucera, Deputy Director Department of Natural Resources 1
P.O. Box 176 j
Jefferson City, MO 65102 i
Manager, Electric Department l
Missouri Public Service Commission j
P.O.
Box 360 J
Jefferson City, MO 65102 l
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ULNRC-1618 o
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r' RESPONSES TOzQUESTIONS ON 5
CA LAWAY PLANT UPRATING t
1.
You stated in your submittal that:
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a)
It was conclhded that, with the exception of the
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turbine-generator system, they (BOP' systems) have.the.
capability to function, properly at the uprated power 1 2 level of 3579 MWt NSSS power'without any modifications o c) j to the existing design.
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b)
.The turbine-generator system is designed to operate at
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3562 MWt' power.
The performance of the system will be monitored closely by Union Electric (U.E. ) between 3562 MWt and 3579 MWt power.
y Provide the results of the reanalysis which demonstrates that the power uprating will not affect the previous staff approval of the plant turbine missile protection.
In this regard, verify that the turbine over-speed protection system 1
provides adequate control under all operating conditions and will assure that a full-load turbine trip will not cause the turbine to overspeed beyond acceptable limits which could result in turbine missiles.
Response
The previous NRC staff approval of the turbine missile protection for Callaway plant was based on the low probability of any damage to a safety-related component.
The lifetime probabilities (before uprating) were given by GE to be 1-.5:x 10-7 i
for the high speed (runaway) case and 1 x 10-9 for the low speed
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case.
The order of magnitude of these, probabilities will not 1
change after uprating to 3579 MWt because:
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a)
There will be no increase in steam pressure,inside the j
turbine, and i
b' The turbine-generator is already designedu for 35 62 MWt.
I Therefore, the increase in its operating power is very l
small (less than 0.5 percent).
Also, the turbine generator for:Callaway has an overspeed d
protection system employing electro-hyrdraulic controls (EHC).
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These EHC's are extremely reliable employing three electrical and 1
j one mechanical speed inputs.
Logic signals are processed in both electronic and hydraulic channels for redundancy.
As per FSAR Section 3.5.1.3, there have been no runaways of General Electric turbines equipped with EHC.
Since there have been no modifications made to the turbine due to uprating, the overspe(d l
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l-protection will-/ work as designed prior to uprating.
That is, I
even aVier. uprating,' a fuE-load turbine trip will not cause the turbine to.overspeed beyond acceptable limits.
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Aa sb,od on the above, it was concluded that missiles from the turf /ine';would:not be a problem after uprating.
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,2.
You stated in you main feedwater system (MFS) evaluation j
that:
a)
At an uprated level, the feedwater system will see a rise in temperature of 1.5 degrees F and a flow increase of less than 1 percent from the previous valve wide open (VWO) design flow, b)
The effect of such a small increase in flow on the flow 1
velocities, system pressure drop and the high pressure heater performance will be negligible.
For the small change in flow, there will be no impact on the performance of the pumps.
These pumps, including their turbine drivers, have sufficient capacity to produce the uprated flow.
Provide assurance that the safety related portion of the MFS piping and the MFS isolation valves can withstand the uprated conditions and continue to perform their safety function.
Response
The safety-related portion of the Main Feedwater System (MFS) piping (inside containment and isolation valve compartment) has been designed conservatively for a temperature of 450 degrees F and pressure of 1185 psig.
After uprating, the feedwater temperature will increase to 446 degrees F.
There will be no appreciable change in the present feedwater pressure of 1033 psig.
The re f ore, the safety-related portion of the MFS piping will not be af fected by uprating.
The Main Feedwater Isolation Valve (MFIV) is designed for 1950 psig and 450 degrees F, wich will not lme exceeded af ter
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6 uprating.
Als,
he change in flow rate from 15.85 x 10 1b/hr to 6
15.96 x 10 lb/hr af ter uprating will not affect the capability of
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the valve to close and provide isolation.
The MFIV is designed j
to close with feedyater flow 31/2 times the current normal flow
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ra te of 15.85 x 10 lb/hr.
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3.
You stated in your steam generator blowdown system (SGBS)
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evaluation thate at the uprated level, the' processing s
r$p, ability of the blowdown system will be utilized to the t
N extent required to keep the chemistry within specification.
In fact, you indicate that the increase in feedwater/ main stey/ flow at the uprated levey.is so' small (less than 1 percent increase) that no impact on SGBS is expected.
Provide. further details rerf ct ping your evaluation which
./ explains how this conclusion was reached, r
ResV>nsef
[9eimarily, the Steam Generator Blowdown System (SGBS) serves to demove impurities in the secondary side water from the following sources:
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Prf.yarytogecondhryleakage; j
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Main conderMy 1qakage; Sodium carry-over f rom deep-bed condensate Idemineralizers;
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W,ar of oiper seconda cy 6 ;cle components and piping.
'S It J,a unlikely itha t, after uprating, the water chemistry will be affected significantly from any of the sources listed above.
The increase in Condensate, Main Feedwater, and Main Steam flow rate is.less than one percent.
o J The Steam Generator Blowdown System has been provided with a continuous blowdown range of 60-360 gpm.
The extent of l
processing require:d 6tJring normal operation is determined by the operator dependi:tg upon the secondary side water chemistry j
requiremv.cs.
The blowdown rate of 360 gpm (90 gpm per Steam i
Generated is for abrormal operation with excessive main condenser leakage.
Therefore, during normal operation after uprating, the water chemistry requirement can easily be met by adjusting the blowdown rate.
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4.
In your proposal, concerning the reactor makeup water system (RMWS) evaluation, you stated that an increased spent fuel pool evaportion rate due to increased heat loads has been calculated.
The present RMWS design provides sufficient makeup water for this demand.
No other change in the demand for reactor makeup water is likely due to the uprating.
Provide further details regarding your evaluation which explains how this conclusion was reached.
Response
The Reactor Makeup Water System (RMWS) supplies deaerated water for makeup and flushing operations throughout the nuclear i
steam supply steam auxiliaries, the radwaste systems, and the fuel pool cooling and cleanup system.
Table 9.2-20 in the FSAR lists the various systems served by the Reactor Make-up Water System.
The water demands on the RMWS are not simultaneous, and the system was designed for the worst case demand.
The RMWS transfer-pumps and the storage tank were designed to deliver 120 gpm to the boric acid blending tee, which is equivalent to the maximum letdown flow f rom the Reactor Coolant System, and were also designed to deliver 150 gpm, as an alternate source, for cooling the contents of the pressurizer relief tank from 200 degrees F to 120 degrees F-in one hour following a pressurizer safety valve discharge.
These worst case demands on the RMWS are not affected I
due to uprating.
(Refer to Section 6.1 of the NSSS Uprating Licensing Report, ULNRC-1471, Attachment 5, Appendix A. )
There will be some impact on RMWS due to the increased demand from the spent fuel pool due to an increase in evaporation rate.
The new maximum evaporation rate calculated by Union Electric is 641 lbs/hr (approximately 1.30 gpm) as compared to the old rate of 355 lbs/hr (approx. 0.719 gpm).
The RMWS is designed to provide 20 gpm to the spent fuel pool for makeup requirement.
Therefore, this small increase can easily be accommodated.
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5.
You stated in your submittal 'that the only systems with an increase'in flow rates are main feedwater, condensate, and main steam systems.
You further state that this increase is less than one (1) percent and, therefore, will not have any significant impact on the flooding analysis in safety-related areas of the plant.
Verify that the original analysis of flooding contains sufficient conservatism and margin to offset the impact of the increased flow rates in these systems in areas containing safety related equipment.
Response
Flooding was not considered to be a problem af ter uprating for the reasons described below.
The original flooding analysis was done in a very conservative f ashion as indicated by the assumptions listed in Appendix 3B of the FSAR.
The worst case pipe failure in each safety-related room was assumed and the maximum flood levels were based on a reasonable delay after the break or crack.
The safety-related areas that could be impacted by flooding due to an increase in the Main Feedwater, Main Steam, and Condensate Flow rates, are the MFIV/MSIV compartment and the Containment.
For Main Feed / Main Steam Isolation Valve compartment, the original maximum flood level was calculated for a feedwater break which was the worst case.
This was considered in spite of the fact that this is a "No Break Zone".
The most limiting single f ailure, a Main Feedwater Control Valve failure in the fully open position, was assumed.
It was assumed that the plant is operating at 100 percent power and to maximize the water which has to be drained from this area, it was assumed that all the fluid discharged from the break will remain water.
In spite of all this conservatism, there was sufficient drainage available such that the maximum water level in Rooms 1508 and 1509 was ze ro, and in Rooms 1411 and 1412 was l'-4" (Reference FSAR Table
- 3. 6-6).
Since a flood level as high as 3'-0" is acceptable in this area, an increase of less than one percent in feedwater flow af ter uprating does not pose any problem.
Inside containment, the worst possible flood level af ter a MSLB was calculated to be at Elevation 2004'-5".
Th!s was calculated conservatively assuming a slow operator action (31.5 minutes).
The total mass input into the containment was 3,834,725 lbm from several sources such as Blowdown, Aux.
Feedwater, Reactor Water Storage Tank, etc.
The mass input from main steam blowdown, which will be the only source affected due to uprating, was only 301,034 lbm.
Therefore, no change in maximum flood level is expected af ter uprating when the main steam flow increases by less than one percent.
Also, note that the worst flood level in the containment is from LOCA which is i
2004'-6".
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6.
Provide a legible, full size copy of Figure 1 - Valves Wide l-Open (VWO) Heat Balance.
l Response.
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Enclosure A provides a copy of the VWO Heat Balance and also I
a copy of the current 100% (of 3425 MWt NSSS) Heat Balance for comparison.
Note that versions of these heat balances are also j
in the FSAR as Figures 10.1-2 and 10.1-3.
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7.
As part of your request to increase the power level at the Callaway Plant by 4.5%, you stated that "in order to confirm that equipment qualification will not be affected, all equipment inside containment was reviewed."
In order to concur with your conclusions, the staff needs the following additional information:
a) Provide the results of your review including any changes that are required to update your Equipment Qualification Program as stated in FSAR Section 3.ll(B) and FSAR Table 6.2.1-2.
This review should consider.all applicable equipment in harsh environments both inside and outside containment.
In addition to the obvious changes that may appear in FSAR Section 3.11, discuss any changes in previously postulated mild environment (s) (e.g.,
are any of these areas previously considered to be mild environments now harsh due to the increase in power level).
If there are new areas that are now considered to be harsh, all equipment within the scope of 10CFR50.49 must be environmentally qualified accordingly; b) Identify and discuss change (s) in environmental profiles (i.e., pressure, temperature, radiation and humidity) for both normal operating conditions and accident conditions resulting from the power uprating; c) As a result of any postulated increase in normal operating temperature, discuss the affects of such changes on the qualified life of essential equipment (i.e.,
if the "10-degree C rule" is used for calculating qualified life, note that an increase of 10 degrees C will reduce the qualified life by 50%.
Also note that significant changes in qualified life also occur with relatively small changes in temperature when using the Arrhenius methodology).
Response
(a)
FSAR Section 3.ll(B).l.2.2 will be updated to include the discussions on pages 11 and 12 of ULNRC-1471,, Appendix B,Section I (3/31/87).
This addresses the four additional 102% uprated power MSLB cases and the evaluation demonstrating no EQ impact.
In addition, FSAR Figures 3.ll(B)-2 and 3.ll(B)-3 will be revised to reflect the envelope of Figures 3, 5,
7, and 9 of the above referenced Section I.
This will result in a slight adjustment to the EQ temperature profile while there will be no effect on the EQ pressure profile.
No changes are needed for FSAR Table 6.2.1-2, since peak MSLB temperature and pressure parameters are unaffected (i.e.,
384.9 degrees F and 48.1 psig) ; however, Section 6.2.1.4.1.4 will be revised to reflect modeling assumptions discussed in Section 6.2 of ULNRC-1471, Attachment 5, Appendix A.
In addition, FSAR Table 6.2.1-57 will be revised regarding initial conditions (e.g., steam pressure, steam generator inventory, mass added by feedwater, etc.) and FSAR Table 6.2.1-58 will be updated to reflect Table 3 of ULNRC-1471, Attachment 5, Appendix B,
Section I.
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As stated on page 12 of the above referenced Section I, there is no EQ impact on Class lE equipment inside l
containment.
.The effects of uprating have also been j
considered in the SNUPPS submittal on-Information Notice 84-90'regarding MSLB's outside containment (steam tunnel) with superheated.blowdowns'(SLNRC 86-06 dated 4/4/86 and ULNRC-1473 dated 3/24/87).. No areas
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previously considered to be mild environments will be
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changed to harsh environments as a result ~of the
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uprating.
This is due to the insignificant process i
temperature changes. discussed in (b) below and, as j
discussed on page 15 of the above referenced Section I, there will be no effect on pipe break-locations, jet impingement analyses, or moderate energy cracks..
1 As discussed in FSAR Section 3.ll(B).l.2.3, HELB's outside containment include main steam line, main feedwater-line, CVCS, and auxiliary steam line breaks.
The feedwater-line break is enveloped by the above MSLB dicussion whereas process conditions for CVCS and L
auxiliary steam lines are unaffected by the upratinc.
l (b)
There are no' environmental profile changes for normal j
operating conditions due to the uprating.
As discussed
'in. Table 2-1 of ULNRC-1471, Attachment 5, Appendix A j
and in Table 1 of ULNRC-1471, Attachment 5, Appendix B Section I, there will be only slight changes to process temperatures and flows.
Average RCS temperatures-remain the same;. steam temperatures decrease slightly; design.feedwater temperature increases by 1,5 degrees i
Floand steam and feedwater flow increase by less than 1%. - The increased. decay heat load on the RHR heat exchangers in rooms 1309 and 1310 of the auxiliary building pertains only to shutdown conditions.
The I
increase in. time (3.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />) to cool the RCS from 350 degrees F to 140 degrees F will not adversely affect post-DBA operability of Class lE equipment in rooms 1309 and 1310 since the calculations that demonstrate this operability in our EQ files (Arrhenius extrapolations) disregard the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the t
test profile.
As discussed in ULNRC-1571 dated 8/7/87 and ULNRC-1561 dated 7/28/87, total'CCW heat exchanger loads actually decrease from those reported in the FSAR.
j The only accident environment profile changes are those L
discussed in (a) above.
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(c). Qualified lives of Class lE equipment are. based on'120 degrees F inside containment and in the steam tunnel and'on 104 degrees F in other areas of the auxiliary building.
Actual ambient temperatures are 10-35 degrees F Jower than these values.
There will be negligible increases in heat loads for the containment cooling and auxiliary building HVAC systems.
As such,
.there will be no effects on equipment qualified lives due to the uprating.
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