ML20118A671
| ML20118A671 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/16/1992 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-13, TAC-M73978, TAC-M73979, NUDOCS 9209240378 | |
| Download: ML20118A671 (14) | |
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B ALT IMORE GAS AND ELECTRIC 1650 CALVERT CLIFFS PARKWAY e LUSBY, MARYLAND 20657-4702 GEORGE C CAEEL semnn v.ct rme unw (410)260-3690 September 16,1992 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2: Docket Nos. 50-317 & 50-318 Summary of Completed Actions; NRC Generic Letter 89-13, "Sersice Water Systera Problems Affecting Safety Related Equipment" (TAC Nos. h173978 and h173979)
REFERENCES:
(a) NRC Generic Letter 89-13. dated July 18,1989, " Service Water System Problems Affecting Safety Related Equipment" (b) Letter from hir. G. C. Creel (BG&E) to NRC Document Control Desk, dated January 29, 1990, Response to NRC Generic Letter 89-13, same subject (c) NRC Generic Letter 89-13, Supplement 1, dated April 4,1990, same subject (d) Letter from hir. G. C. Creel (BG&E) to NRC Document Control Desk, dated January 6,1992, Revised Response to NRC Generic Letter 89-13, same subject (c) Letter from hir. G. C. Creel (BG&E) to NRC Document Control Desk, dated August 4,1992, Revised Testing Schedule, same subject Gentlemen:
NRC. Generic Letter 89-13, Reference (a), outlined concerns ;cgarding the safe operation and maintenance of the service water (SRW) systems and identified several recommendations associated with ensuring proper heat transfer capability of SRW system components.
Baltimore Gas and Electric (BG&E) Campany's response to Generic Letter 89-13 was provided in Reference (b). In that response we outlined our planned actions and stated all initial activities will be campleted before plant st >rt up (hinde 2) from the next refueling outages for each unit. This ,
letter summarizes the Generic Letter 89-13 activities completed for Unit 1. g o
9209240378 920914 PDR ADOCK 05000317 PDR Ok(f kN6>qp (
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. Document Control Desk September 16,1992
-. Page 2 Reference (b) outlined five tasks that would be performed to address the recommended actions of the genene letter.
TASK I Sultwater Illoroutine Program All initial activities have been completed.
TASK 2 Test Procrum
'The original commitment to test heat exchangers was revised in References (d) and _(e).
Enclosure (1) is a summary of the initial test results. Generic Letter 89-13 requests us to implement the recommended actions or justife our alternatives to them. Enclosure (2) is a " Justification of -
Alternatives to Testing" requested in the Reporting Requirements of Generic Letter 89-13 page 7.
Initial activities are complete. For testing the SRW and Component Cooling Heat Exchangers, we could not establish satisfactory r:lant conditions to meet EPRI Heat Exchanger Performan':e-Monitoring Guidelines. Consequently, the baseline tests for these heat exchangers did not produce conclusive results. As described int _ Enclosure (2), we are confident that these heat exchangers adequately perform their heat removal functions. In order to provide further assurances _that these open-cycle heat exchangers can perform their heat removal function, we are developing test methods to retest these heat exchangers when pisnt conditions are satisfactory.
In Reference (b), we committed to perform initial testing of our closed eycle systems (SRW and Component Cooling) to determine which heat exchangers should be included in the periodic test program. This commitment was a result of our inability to confirm the adequacy of our chemistry control program over the total operating history of the plant, Based on the results of testing and inspecting these closed cycle systens, we have concluded the quality of our chemistry control program maintains adequate heat transfer rapability. Future periodic testing of Unit 1 closed-cycle systems under the scope of Generic Letter E9-13 is not necessary and will not be performed.
TASK 3 Inspection und Maintenanco socrum l
All planned actions have been completed. All underground saltwater pipe was inspected. Repairs were made as necessary. The ultrasonic test program has been reviewed and revised.
I TASK 4 Licensine Itasis Review l
l The planned actions described in Reference (b) have been completed. System and heat exchanger software hydraulic models have been developed. The software was validated by duplicating a number of BG&E hydraulic calculations and comparing the results to the original calculations and actual plant data. System drawings were reviewed and walkdowns were performed to ensure the systems were not vulnerable to single active failures l:
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Document Control Desk Septemb;r 16,1992 Page 3 TASK 5 Service Water Systems Pronnim Review The planned actions described in Reference (b) have been completed with the exception of procedure upgrades. The Procedure Update Project is on schedule to complete the upgrades to the technical procedures by December 1994.
Should you have any further questions reganting this matter, we will be pleased to discuss them with ,
you. )
Very truly yours, N
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for G. C. Creel Senior Vice President GCC/JMO/dtm/bjd Enclosures cc: D. A. Brune, Esquire J. E, Silbe> g Esquire R. A. Capra, NRC D. G Mcdonald, Jr., NRC T. T. Martin, NRC P. R. Wilson, NRC R. I. McLean, DNR J. II. Walter, PSC i
1 l' age 1 of 7 ENCLOSURE (I)
IIEAT EXCIIANGER TEST PROGRAM IN TEST TEST TEST PROGRAM TYPE RESULTS COMMENTS SYSTEM IIEAT EXCIIANGER Y I Inconclusive due to Tube side cleaned each quarter. Traiaient Test Component Cooiing Methodology will be acyclopal by IIcat Exchangers or law saltwater flow.
II.B See Enclosure (2) January 31,1993. Transient test wi!! be ,
S 11 & 12 for details. periormed during the next planned shutdown l A l to Mcdc 5 after April 30,1993.
L I T
W A Tube side cleaned each quarter. Test will be Y I Inconclusive due to T Senrice Wat . r performed when the other train is removed from E IIcat Exchangers or low heat load. See 11 B Enclosure (?) for service after January 31,1993.
R 11 & 12 details Y I 11 & 12 SAT Air side cleaned.
ECCS Pump Room S Air Coolers III.A.
Y 11 & 12 or S
Ill.fi T
E M N/A Intake Structrre N N/A N/A Air Coolers g
Page 2 of 7 ,
ENCLOSURE (1) 11 EAT EXCIIANGER TEST PROGRAM IN TEST TEST TEST
' SYSTEM IIEAT EXCIIANGER PROGRAM TYPE RESUL'IS COMMEN~IS Containment Air Y Ill.A. 12 & 13 SAT Based on cleaning all coolers and testing the two Coolers 11,12,13,14 or most limiting coolers, it was not necessary to test i III.B #11 and #14.
S Spent Fuel Pool Y II.B. 11 & 12 SAT No cleaning necessary.
E Cooling IIcat Exchangers R ._
V Diesel Generator Coo.ers Y II.A 11 EDG ucket Water Nos.11,12 & .21 EDG coolers are inspected at i Cooler & Air Coolant 18-month intervals. Results have been SAT. All C 11 cat Exchanger coolers are identical. Testing Lube Oil Coolers is .
E tested SAT.11 EDG not practical; however, inspections indicate Gere Lube Oilcooler has been no r.ced to clean them. See
- inconclusive due to Enclosure (2) for details. -
kw oil flow W
A Main Feed Pump Turbine N NA NA NA i T Lube Oil Coolers E
R ELIC Oil Coolers N NA NA NA Main Turbine Lube N NA NA NA S Oil Coolers Y
S Generator / Exciter N NA NA NA T Air Coolers E ~
M Stator Ligaid Cooling N NA NA- NA IIcat Exchar.gers (U-1)
Ilydrogen Seal Oil .N NA NA- NA Coolers (U-2) -
Page 3 of 7 , .
ENCLOSURE (1) .
IIEAT EXCIIANGER TEST PROGRAM IN TEST TEST TEST SYSTEM IIEAT EXCIIANGER PROGRAM TYPE RESULTS COMMENTS Aux Feedpump Room N NA NA NA S Air Coolers E
, R isophase Bus Duct Coolers N NA NA NA i
V I Condenser Air Removal N NA NA NA i C Pump Seal Coolers E
Waterbox Priming N NA NA NA Pump Seal Coolers W Condensate Booster Pump N NA NA NA A Lube Oil Coolers T
E Instrur'ent and Plant N NA NA NA R Air Compressor Coolers Turbine Plant Sample N NA NA NA Coolers S
Y M/U Demin Vacuum N NA NA NA S Pump Cooler (U-1)
T E N 2Compressor After N NA NA NA M Coolers (U-1)
Steam Generator Bkmdown N NA NA NA Recovery System Ileat Exchanger i
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Page 4 of 7 : , ..
ENCLOSURE (1)
IIEAT EXCIIANGER TEST PROGRAM .
IN TEST TEST TEST SYSTEM IIEAT EXCHANGER PROGRAM TYPE RESULTS COMMENTS C Shutdown Cooling Y II.B. 11 & 12 SAT No cleaning necessary.
O Ileat Exchangers M 11 & l2 P
O HPSI Pump Seal & Y IV.B. Flow test for Bearing and seal cooler temperature maintained N Bearing Coolers 12 coolers SAT below design limit. Based on testing the limiting E 11,12, & 13 pump coolers (#12 HPSI), testing of the
, N #11 & 13 coolers was not necessary.
T LPSI Pump Seal & N NA NA NA '
C Bearing Coolers O
O Containment N NA NA NA L Penetration Coolers I Main Steam N Main Feedwater G Letdown !
RC Sample S/G Blowdown S
Y Reacter Vessel N NA NA NA S Support Coolers T
E S/G Lateral Support N NA NA NA M Coolers
A Pcge 5 of 7:. .
ENCLOSURE (l_).
IIEAT EXCIIANGER TEST PROGRAM i
~i IN TEST TEST TEST SYSTEM IIEAT EXCIIANGER PROGRAM TYPE RESULTS COMMENTS C Reactor Coolant , N NA NA NA 7 O Waste Evaporators
- M '
P Control Element Drive N NA NA N/-
O Mechanism Coolers N ,
E Reactor Coolant Pump N- NA NA NA N Seal and Lube Oil Coolers
-T Reactor Coolant Drain N NA NA NA Tank Heat Exchangers C
O Letdown lical Exchanger N NA NA NA O
L Waste Gas Compressor N NA NA NA I Coolers N
G RCW Degasifier Vacuum N NA NA NA Pump Coolers S NSSS Sample Coolers N NA NA NA Y RC Sample S SG Blowdown Sample '
T MWS Sample E
M Post Accident Sampic N NA NA NA System Cooler ,
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g w 4' S 3 , 1 m --
.)7 m
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ItgeGof7 J. _y ENCLOSURE (1) .
1IEAT EXCIIANGER TEST PROGRAM .
IN TEST TEST TEST SYSTEM HEAT EXCHANGER PROGRAM TYPE RESULTS COMMENTS CCS Gas Analyict Sample N NA NA NA O O .Y Coolers MOS >
P L.T
- OI E MWS IIcat Exchanger N NA NA NA NNM EG ;
N !
T S/G Blowdown RAD Monitor N NA NA MA Sample Cooler I
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ENCI OSURE (1)
IIEAT EXCIIANGER TEST PROGRAM TEST TYPES
- 1. Monitor and record cooling water Cow and inlet and outlet temperatures for all affected heat exchangers during the modes of operation in which cooling water is flowing thtough the heat exchanger. For each measurement, verify that the cooling water temperatures and Dows are within design limits for the conditions of the measurement. The test results from periodic testing should be trended to ensure that now tlockage or excessive fouling accumulation does not evist.
II.A. Perform functional testing with the heat exchanger operating, if practical, at its design heat removal rate to verify its capabilities. Temperature and flow compensation should be made in the calculations to adjust the results of the design conditions. Trend the results, as explained above, to monitor degradation.
II.B. If it is not practical to test the heat exchanger at the design heat removal rate, then trend test results for the heat exchanger efficiency or the overall heat transfer coefficient, Verify that heat removal would be adequate for the system operating with the most limiting combination of now and temperature.
Ill.A Perform ef0ciency testing with the heat exchanger operating under the maximum heat load that em be obtained practica!!y. T=t re: ult: should be corrected for the off-design conditions. Design heat removal capacity should be verified. Results should be trended, as explained above, to identify any degraded equipment.
111.13 If it is not possible to test the heat exchanger to provide statistically significant results (for example, if error in the measurement exceeds the value of the para.acter being measured),
then
- 1. Trend test results for both the air and water Dow rates in the heat exchanger.
- 2. Perform visual inspections, where possible, of both the air and water sides of the heat exchanger to ensure cleanliness of the heat exchanger.
IV.A. If plant condition:. allow testing at design heat removal conditions, verify that the heat exchanger performs its intended functions. Trend the test results, as explained above, to monitor degradation.
IV.II. If testing at design conditions is not possible, then provide for extrapolation of test data to Design conditions. The heat exchanger efficiency or the overall heat transfer coefficient of the heat exchanger should be determined whenever possible. Where possible, provide for periodie visual inspection of the heat exchanger. Visual inspection of a heat exchanger that is an integral part of a larger component can be performed during the regularly scheduled disassembly of the larger component. For example, a motor cooler can be visually inspected when the motor disassembly and inspection are scheduled.
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. ENCLOSURE (2)
JUSTIFICATION OF ALTERNATIVES TO TESTING FOR GENERIC IEITER 8913 Described below is the justification of actions we have tak in lieu of the testing we committed to in Reference (b) for the following heat exchangers: Service Water (SRW), Component Cooling, liigh Pressure Safety injection (llPSI) pumps, Emergency Diesel Generator (EDG) and Containment Air Cooling. While evaluating the initial test data for the current Unit I refueling outage, we discovered some of tne measured parameters did not meet the criteria of IIcat Exchanger Performance Monitorine Guidelines (EPRI NP4552). Specifically for the SRW and Component Cooling licat Exchangers, we were unable to obtain enough heat load at steady state conditions to achieve minimum acceptable differential temperature to assure conclusive test results. The EPRI Guidelines are based on steady state conditions. Section 5.5.1 of the guideline recommends a minimum acceptable differential temperature that is based on test instrument accuracy. For No.11 EDG, we are unable to obtain sufficient lube oil Covohrough the EDG lube oil cooler to assure conclusive test results. The EPRI guideline recommen that the now should be a fully developed turbulent How (Section 5.4.3). For the llPSI pumps' seal and hearing coolers, we concluded, since testing verified that No.12 IIPSI coolers can perform their heat removal function and all Unit 1 IIPSI pumps are identical, testing of the Nos.11 and 13 IIPSI pumps is not necessary. Similarly for Containment Air Coolers, we concluded, since testing verified that cooler Nos.12 and 13 can perform their heat removal function and all Unit I containment coolers are identical, testing of the Nos.11 and 14 Coolers is not necessary, I. SEltVICE WATER ANI) COMPONENT COOL.ING llEAT EXCIIANGERS Sersice Water lleat Exchancer i
InsufGeient heat load was available on the SRW lleat Exchangers during initial tests to obtain a minimum acceptable differential temperature. Both of these heat exchangers will be retested with maximited heat loads during normal operations at 100% Reactor Power. Their normal operating heat loads at 100G Reactor Power are approximately 25% of their accident heat load. A new test method, requiring minor rndifications to the Saltwater System, will be developed. The new test will be performed on each heat exchanger after January 31,1993, l when the test method and modiReations are completed.
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Component Cooline lleat Exchangers Similarly, insufficient heat load was available on the Component Cooling IIcal Exchangers.
Du 95, Fring normal operations, the system maintains component cooling water temperature to ensure the contgolled bleed-off temperature for the Reactor Coolant Pump Seal does not fall below 110 F. In order to meet this requirement, the saltwater flow was insufficient to consider the test valid. A test methodology will be developed and validated to account for the transient heat exchanger conditions that will exist during a plant cooldown.
! Tlie methodology will be developed by January 31,1993. We will develop the performance test and obtain required instrumentation within three months of completing the test methodology. We expect to be able to test the component cooling heat exchangers during the next planned shutdown after April 30,1993, that includes a cooldown to Mode 5 when the transient heat load on them is maximized.
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ENild)SUltE (2)
. JUSTIFICATION OF Al,TERNATIVES TO TESTING 1 OR GENERIC LEITER 8913 There is no safety impact due to extending the heat exchanger test schedule. Generic lxtter 8913, Supplement 1 l Reference (c), Question 6, page 19] states that a program of periodic inspection, maintenance and clean ng may be proposed as an alternative to heat exchanger testing when it is impractical to perform these tests. It is our opinion that conclusive results can only be obtained if these heat exchangers are tested at higher heat loads when the effect of instrument inaccu'. vies are at acceptable levels. Therefore, llG&E is not proposing an alternative to testing the SRW and Component Cooling flent thchangers, llowever, we have concluded an extension to the schedule is acceptable based on the following actions that we have taken. These actions are similar to those that would be appropriate for a proposed ahernative:
- 1. A design review of these heat exchangers has been conducted. We have confirmed from the review that their design is adequate to accomplish the requircJ safety functions under worst case accident conditions.
- 2. The tube side of both sets of heat exchangers have been cleaned by
- bulletin ( during the curient Unit 1 outage. Tube hulleting is currently performed quarterly.
- 3. The combination of maintenance, 'nspection, testing activity and chemistry control of the SRW and Component Cooling System provides us with reasonable assurance that these systems have not experienced any change in heat it:msier cui nbility since these inspections.
6 SRW - The shell side of the SRW Ucat Exchangers was inspected and videotaped in June WA), and found clean.
- Ce mponent Cooling - The shell side of the Shutdown Coolin;, lleat Excham;cr was visually inspected during the current outage and found clean.
Component Cooling Water flows through its shell side.
Therefore, there is no safety impact from extending the heat exchanger test schedule.
II. plERGENCY 1)lENEl, COOL.ERS The EDGs have three coolers cach - a lobe oil cooler, a jacket water cooler and an air coolant heat exchanger - which are cooled ty SRW (a closed system). After our original tests failed to provide conclusive test results, we made permanent and temporary modifications to me No,1I EDG to improve the test. From the second test, we obtained conclusive results that both the jacket vaier cooler and the air coolant heat exchanger tre capable of performing their heat removal function for No.11 EDO. We did not obtain conclusive test sesuhs for the No.11 lu' "I cooler since the 1.be oi) Oow was not the fully developed turbulent flow recomme y the EPRI Gttidelines. Pe vendor recommenued mimuu a lube oit temperature F wouldof not160,rforming a test that meets the allow us to obtain acceptable tube oil flow. e endor ha> reviewed the No.11 EDG test data and confirmed that no other optiom are ahk: to obtain conclusive 't results without removing the cooler from ti.- EDG for iutther testing. 'Iherefore, we have concluded that it is not practical to test any liDG !ube oil cooler We inspect EDG coolers on 18-month intenals per vendor recommendations to verify their cleanliness. These inspections indicate there is 2
JNCLOSilHE G1 JtNUFIPATION OF ALTERNATIVES TO TESTING I
FOR GENERIC LLTIER 8913 '
no need to clean them. He lube oil is sampled and analyzed monthly. Reference (c) 1 IOucation 6, page 19] states that when it is not 3ractical to test a heat exchanger, an alternative such as inspection may be proposed. Adt itionally, during the performance of the engineering test for Generic 1.ctter 89-13, we observed high heat exchanger bypass flow for the No.11 EDO lube oil cooler. This is a qualitative incication that its heat transfer capabilities are adequate to perform its intended function.
We are confident that all of the EDO coolers are performing their heat removal function.
Our decision is consistent with Reference (c) (Question 8, page 20) which states that the initial heat exchanger test program may consist of performance testing of the most limiting heat exchangers combined with maintenance or cleaning of o*hers. The family of heat
, exchangers is identical for each EDO. The engine-side water for all EDOs is similar. The water chemistry of the jacket water cooler and air coolant heat exchanger is identical since these sptems are typically cross-connected. Ilowever, the water for No.1I EDO is the most s limiting since historically we have had more problems maintaining its water chemistry control than the otner two EDOs.
%crefore, there is no safety impact from substituting inspection for a heat exchanger test.
Since the SRW System is a closed system that is exhibiting no system-wide corrosion, we can now confirm the quality of our chemistry control prograrn is sufficient to maimain adequate heat transfer capability. Future periodic testing of the heat exch4mgers is not necesary as long as the chemistry cortrol program is adequately maintained l Reference (a), page 5).
t il. LilGli PRESSUlti: sal'IrlY INJECTION PUMP COOI.ERS He llPSI pumps include integral seal and bearing coolers that are mounted to the pump bse and supplied by the pump ver. dor. There is continuous How through the component cooling water skle of the cooiers. Here is flow through the Reactor Coolant System (RCS) side of the bearing ccaler only when the pump is operating. Otherwise, the RCS side is stagnant. The No.12 pump was tested to verify adequate component cooling How and that the bearing and seal cooler temperatures can be maintained below the design limit as we committed in Reference (b). After reviewing these results and coniltming the Unit 1 pumps are identical, we concluded there was no benefit from testing the other two pumps. Plant records were reviewed. There is no history of operating problems or rnaintenance orders for the Unit 1 pump coolers. The water chemistry progiam for the RCS side of the seal cooler is a documented, high quality closed k>op water system. The component cooling water side of the !! PSI bearing coolers are always operated cross-connected, so the water chemistry is identical in all llPSI cooleis. Visual inspection of the shell side of the Shutdown Cooling Ileat Exchanger indicates that the Component Cooling Water System is clean. We have determined the No.12 IIPSI pump bearing cooler is the most limiting since No.1211 PSI-pump has had the lowest run time. Therefore, it has experienced the largest amount of stagnant conditions where any foulant on the RCS side is most likely to form a colloid and precipitate.
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. , ILNL'l OSUl{E (21 JUSTil'lCNilON OF AlTEltNATIVES TO TINI'ING l'OR GENERIC Ll!!TEll 8913
'lhe cambination of the visual inspection of the Shutdown Cooling Ileat Exchanger, the results of the No.12 IIPSI test and identical construction of the Unit ? IIPSI purips gives us confidence that the llPSI coclers have adequate heat transfer capability to perform their intended function. Our decisan is consisterit with Reference (c). Therefore, there is no safety impact from testing only the No.1211 PSI Coolers. Since the Component Cooling Water System is a clo ed system that is exhibiting no system wice corrosion, we can now confirm the quality of our chemistry control program is sutiicient to maintain adequate heat transfer capability. Future periodic testing of the heat exchangers is not necessary as long as the chemistry control program is adequately maintained [ Reference (a), pa;c 5).
IV. CONTAINS1ENT AIR COOL.1RS There are four Containment Air Coolers in Unit 1. Cooler Nos.11 and 12 are normQ supplied by SRW Subsystem 11. Cooler Nos. I'l and 14 are normally supplied by SRW Subsystem 12. Ilowever, any cooler can be supplied from any subsystem.
All four coolers were cleaned. We have determined the most limiting cooler from each subsystem. For Subsystem 11, it is Cooler No.12 since it has the lowest SRW flow. For Subsystem 12, it is Cooler No.13 since it has the most restrictive air flow configuration.
Testing verified that these two limiting coolers adequately perform their heat removal function. Therefore, the test results and identical construction of the coolers gives us confidence that Unit 1 containment air coolers have adequate heat transfer capability to perform their intended function. Our decision is consistent with Reference (c). Therefore, there is no safety impact from testing two of the four air coolers. Similar to the llPSI coolers, future [miodic testing of the air coolers is not necessary as long as the chemistry control p:ogram is adequately maintamed l Reference (a), page 5).
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