ML20070E025
| ML20070E025 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 06/30/1994 |
| From: | IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT |
| To: | |
| Shared Package | |
| ML20070E023 | List: |
| References | |
| NUDOCS 9407140011 | |
| Download: ML20070E025 (10) | |
Text
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RTS-240A to NG-94-2451 Page 1 of 1 PROPOSED CHANGE (RTS-240A) TO THE DUANE ARNOLD ENERGY CENTER TECHNICAL SPECIFICATIONS The holders of license DPR-49 for the Duane Arnold Energy Center propose to amend Appendix A (Technical Specifications) to said license by revising the attached pages as indicated.
The List of Affected Pages is given below.
LIST OF AFFECTED PAGES vii 3.8-6 3.8-7 3.8-11
SUMMARY
OF CHANGES:
The following list of proposed changes is in the order that the changes appear in the Technical Specifications.
Page Description of Changes vil Remove Figure 4.8.E-1 from Technical Specifications List of Figures.
l 3.8-6 Revise surveillance requirement for ESW pump and valve operability test to state "As specified in the IST Program."
Remove the requirement for the flow rate test.
Remove the requirement for weekly testing when river water temperature exceeds 80 F.
Add hourly surveillance for river water temperature.
Revise surveillance requirement for one ESW pump inoperable to delete reference to Surveillance 4.5.G.1.
(This surveillance requirement necessitates operating the Emergency Diesel Generator, which is inappropriate for a train of ESW inoperable.)
3.8-7 Delete this page.
3.8-11 Add information to the Bases to describe the revised surveillance requirements and make some editorial changes.
9407140011 940630 PDR ADOCK 05000 1
P
t DAEC-1 TECHNICAL SPECIFICATIONS LIST OF FIGURES FIGURE fiUMBER TITLE 1.1-1 Power / Flow Map 2.1-1 APRM Flow Biased Scram and Rod Blocks 4.1-1 Instrument Test Interval Determination curves 4.2-2 Probability of System Unavailability vs. Test Interval 3.3-1 Thermal Power vs Core Flow Limits for Thermal Hydraulic Stability Surveillance 3.4-1 Sodium Pentaborate Solution Volume Concentration Requirements 3.4-2 Minimum Temperature of Sodium Pentaborate Solution 3.6-1 DAEC Operating Limits
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i vil-RTs -zvo A Amendment No.157,75A.766,J67.789.J83,197-oW44
I i
i DAEC-1 LIMITING CONDITIONS FOR OPERATION SURVEI* *_ANCE REOUIREMENTS E.
Emercency Service Water System E.
Emercency Service Water System 1.
Except as required in 1.
Emergency Service Water System Specification 3.8.E.2 below, both surveillance shall be as follows:
Emergency Service Water System loops shall be OPERABLE whenever a.
Simulated auto-Once/
1rradiated fuel is in the reactor matic actuation OPERATING CYCLE vessel and reactor coolant test.
l temperature is greater than 212*F.
b.
Pump and motor tac./0 act.th; operated valve As s peciFred in g
OPERABILITY 4h*::5T Pr*y=**
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Tisw T;te Test-2.ch Ise;;;ncy
'f t;r r;j;; p. y Ce..ie; ".?;te;
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- d; 20*".-
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With one of the Emergency Service 2.
With one Emergency Service Water l
Water System pumps or loops System pump or loop inoperable, I
inoperable, REACTOR POWER the OPERABLE pump and loop s 11 OPERATION must be limited to b verified f; p nornang y &
l seven days unless OPERABII.MY of additica, th...yul.
.a; cf_
that system is restored vithin
-specification 0. 0.0.1 ;h:11 5; l
this period. During sur,h seven
-mes,-
days all active componr.nts of the other Emergency Servica Water
- c. River Wa.ter Te mpe ~f u re System shall be OPERASLE, provided the requirements of Specification 3.5.G are met.
([) Recocol r*Ve r w e. h r f erpe re f er-bod.
y bo*cl river Wa te r 3.
If the requirements of g Vffh any y
Specification 3.8.5 cannot be y,
ceJ s n3 p M *F ve c' fy 3
met, be in at least HOT SHUTDOWN 8 '"P COLD SHUTDOWN within the o f +6 pudou 3 gy within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in Ae aver ^j e g,7g re d; ny g 95 *F e ve, ry hw r following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, d 24 b*"rs.
4 3.8-6
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Amendment No.10,32,733,J A3, ff D,197 o6,/W
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700 600 b/
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N 80 85
'90 95
.. River Water Temperature - Degreet F
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Duane Arnold Energy 65n't Iowa Electric Light.and P r company Technical ~ Specifications DAEC Emergency Service Water. Flow Requirement.-
Figure 4.8.E-1
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\\-
ndment No.197 3.a-7 RTs-2.4oA
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olo/94
4' e
DAEC-1 stored fuel oil will provide further assurance that the fuel oil is not deteriorating to the point that EDG operation would be af fected.
This characteristic is trended so that actions can be taken to restore fuel quality prior to reaching unacceptable levels.
Should a test result show unacceptable particulate accumulation which does not fit an established trend, a second sample is allowed to be tested prior to
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taking actions to restore the fuel.
Although the station batteries will deteriorate with time, utility experience indicates there is almost no possibility of precipitous failure.
The type of surveillance described in this specification is :
that which has been demonstrated over the years to provide an indication of a cell becoming irregular or unserviceable long before it becomes a failure.
1 The Service Discharge Test provides adequate indication of the batteries' ability to satisfy the design requirements (battery duty cycle) of the associated DC system.
This test will be performed using simulated loads at the rates and for the durations specified in the 1
design load profile.
The Performance Discharge Test provides adequate indication and assurance that the batteries have the specified ampere hour capacity.
The rate of discharge during this test shall be in accordance with the
'i manufacturer's discharge characteristic curves.
The results of these tests will be recorded and compared with the manufacturer's l
1 recommendations of accept C5w The r enev servica e
y em has two loops with one pump each.
If 7 ::rci:: =-*--
ystem loop becomes inoperable, the other.
Y pr$g :
sGYrletent-co'oling to components to assure performance of
.j ESW ides the safety function after an accident.
Continued plant operation with
-j one. loop-inoperable tricted *o a e n-day period during which-4 time the OPERABL 4.
.,-..:7 0;.. i;; 'f:t r loop is verified to be OPERABLE.
ESW s
_..; - - _ _ _ _ _ _7_
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,_s The ESW System is a parallcl branch flow system A comprehensive analysis of ESW flow requirements was performed to evaluate the maximum individual design heat loads of the components cooled by the ESW System. Dascline branch flow verification tests have been performed to assure that all the individual component cooling requirements are met. Vonitoring the pump performance in accordance with the ASME In-Service Testing program and periodic flow measurement in the major branches provides assurance that the ESW System is performing acceptably. The surveillance test intervals for the ESW
(.l pumps and associated valves are based upon Section XI of the ASME Code.
The ESW analysis established minimum branch flow rates necessary to remove the design heat load with i
river water temperatures up to 95'F. Peak temperatures exceeding 95'F will not degrade long term ESW performance, however river water temperature trends at or near 95 F couldjcopardize ESW performance.
Therefore, when river water temperatures exceed 95'F, a rolling 24-hour average is calculated. If, at any time, the 24-hour average exceeds 95'F, the ESW System cannot reliably perform its design ftmetion in the event of an accident and is considered inoperabic.
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RTS-240A to NG-94-2451 Page 1 of 4 IES Utilities Review of Technical Evaluation of DAEC ESW Technical Specification Change Request This document provides IES Utilities' (IES) responses to the NRC concerns discussed in Reference 2.
Those concerns are discussed in the conclusions (section 8) of the Technical Evaluation (Reference 2).
NRC concern:
" Fouling factors.
The fouling factors used for the ESW flow requirements appear to be non-realistic for DAEC service use."
IES Response:
The assumed Fouling Factor in the original calculation was 0.0005.
Based upon NRC concerns, this value was reconsidered.
IES routinely cleans the heat exchangers so that' fouling is not expected to be as severe; however, the Tubular Exchanger Manufacturer Association (TEMA) tables specify a fouling factor of 0.001 for this application, so that value will be used at the DAEC.
Heat transfer testing performed on the heat exchangers provides additional support for the use of 0.001 as the fouling factor.
Therefore, the calculations have been revised to use the more-conservative value of 0.001.
NRC Concern:
" Methodology.
Some calculations employed an approach which involved too many unknowns, or did not sufficiently document the calculational results to assure that the approech was adequate, as was the case in employing the Wilson Method."
IES Response:
Heat exchanger calculations employed different methodologies, depending on the information available for each heat exchanger.
l The analysis of the Emergency Diesel Generator (EDG) heat exchangers assumes full shell side flow to maximize the heat load on the cooler and ultimately the ESW flow l
requirement.
The calculated EDG shell side film coefficient was conservative (i.e.,
lower, resulting in increased ESW required flow) with respect to the film coefficient originally used by the vendor.
The analysis of the room coolers included a calculated number of tube rows in order to match the inside and outside heat transfer
}
1 RTS-240A to NG-94-2451 Page 2 of 4 rates.
The calculated number of tube rows is less than actual, resulting in greater-than-actual required ESW Flow.
The analysis of the Control Building Chiller condenser utilized the Wilson Method because the vendor was unable to provide design data for the specific heat exchanger installed at the DAEC.
The Wilson Method, which takes advantage of the fact that the freon film coefficient remains constant over the normal condenser operating range, was used to determine the required ESW flow rates.
This is conservative, since condenser performance is a function of tube side (ESW) flow rate and fouling factor only.
NRC Concern:
" Assumptions.
In many cases, assumptions used in the calculations could have been verified and hence removed as assumptions with a request for information to DAEC or vendors."
IES Response:
IES and its contractor did perform many field walkdowns in order to gather as much information as practicable.
Some of the assumptions could have been verified through additional walkdowns, however all assumptions used were conservative as confirmed by subsequent walkdowns.
NRC Concern:
"As-built conditions.
Field observations gave the impression that the calculation preparers did not perform walkdowns or request confirming information from the field."
IES Response:
As stated above, field walkdowns were performed.
Subsequent walkdowns have further confirmed that the data used in the calculations are either accurate or conservative.
The concern specifically deals with the amount of uninsulated piping.
The amount of heat added to the rooms by uninsulated piping is a small portion of the total heat load due to equipment and piping.
Furthermore, several conservatisms in the calculation outweigh any impact due to uninsulated portions of piping:
actual pipe diameters were used for determining surface area, however the heat transfer coefficient for the smallest diameter pipe was used throughout (for a greater
RTS-240A to
~
NG-94-2451 Page 3 of 4 heat transfer coefficient); all pipes were assumed to be horizontal (also r9sulting in a greater heat transfer coefficient because the characteristic dimension is greater for horizontal pipe); higher insulation heat conductance was used (0.2175 vs.
0.1806); and finally, a 5% margin was added to the total room heat loads.
Therefore, because of the margin already included in the calculation and the relatively small amount of additional heat attributable to uninsulated portions of piping, the calculations have not been revised to incorporate this comment.
NRC Concern:
" Equipment Qualification (EQ).
In at least one calculation (RHR pump seal cooling), an argument is made that the EQ temperature envelope for the seal can be exceeded for a short time.
Supporting justification for this condition was not addressed."
IES Response:
During minimum flow conditions, the RHR pump seal temperature does exceed the vendor's specified maximum, however, this condition only exists for short periods of time.
The vendor was contacted regarding this matter and confirmed that higher than specified seal cooling water temperatures are acceptable for short periods of time.
IES has reviewed the modes of RHR operation and determined that the safety-related modes require a much lower amount of seal cooling flow.
The minimum flow bypass to the torus is a short duration feature i
for protection of the RHR pumps.
No operational conditions result in minimum flow bypass for more than a few minutes at a time.
Therefore, since the seal cooling water temperature exceeds the manufacturer's specified maximum for a very short time and the manufacturer has stated that this condition is acceptable for short times, IES has concluded that this condition is acceptable.
NRC Concern:
" Administrative controls.
A revision to one calculation, and all the calculations dealing with control room habitability, lacked checker sign-off."
IES Response:
The calculations conform to the contractor's IES-approved Quality Assurance Program.
The contractor's procedures allow a document checker
m.
i-r.,,.,
RTS-240A to NG-94-2451 Page 4 of 4 the option to either initial each page, or just the cover sheet of a calculation.
The checker exercised both options for various calculations and revisions.
All calculations and revisions thereto were verified in accordance with the contractor's IES-approved Quality Assurance Program as required.
NRC Concern:
" Computer code validation and verification.
The documentation for the pump room cooler coil computer code was validated but the review team did not have sufficient documentation to assure verification."
IES Response:
Code verification was performed as part of the calculation checking process.
The checker of the calculations is responsible for verifying that the purpose, background, approach and assumptions are correct.
The computer code. utilizes basic heat transfer equations and is based on methods developed by the original coil manufacturer.
Summary:
In general, it appears that many of the NRC reviewer's concerns could have been resolved through additional dialogue or a formal request for information.
-IES is anxious to provide any information necessary to answer NRC concerns so that-this Technical Specification change request can be resolved.
The proposed change will improve ESW reliability by not requiring additional. testing when river water' temperatures are higher, and will simplify operability testing by specifying ESW surveillance in accordance with the DAEC Inservice Testing program.
A further enhancement.
is the new surveillance on river water temperature.
These requirements are consistent with the draft Improved Technical' Specifications, and together will demonstrate the system's capability to perform its design function.