ML20087C692

Informs of Changes Made to Programs Re Revised Response to NRC Generic Ltr 89-13, Svc Water Sys Problems Affecting Safety Related Equipment

ML20087C692
Person / Time
Site:	Calvert Cliffs
Issue date:	01/06/1992
From:	Creel G BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-13, TAC-M73978, TAC-M73979, NUDOCS 9201140360
Download: ML20087C692 (10)

Text

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i BALTIMOr E GAS AMJ E L E' ,T R I C 1650 CALVERT CLIFFS PARKWAY . LUSBY, MARYLAND 20657 4702 GEoPot C CREEL vice PatsiotNT Nvckt an ENTnoy (480) 860-e456 January 6,1992 U. $. Nuclear Regulatory Commission Washington,DC 20555 ATTENTION: Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Phnt Unit Nos.1 & 2; Docket Nos. $#317 & 50-318 Revised Response to NRC Generic Letter 89-13,

" Service Water 7 stem Problems Affecting Salety Related Equipment"(TAC Nos, h173978 and h173979)

REFERENCES:

(a) NRC Generic Letter 8913, "Senice Water System Problems Affecting Safety Related Equipment," dated July 18,1989 (b) Letter from hir. G. C, Cicel (BG&E) to NRC Document Control Desk, dated January 29, 1990, Response to NRC Generic Letter 8913, same subject l

i l Gentlemen:

l NRC Generic Letter 8913. Reference (a), outlined concerns regarding the safe operation and maintenance of the senice water systems and identified several recommendations associated with ensuring proper heat transfer capability of service water system components. Recommendations were provided to confirm that plant service water systems continue to meet the heat removal requirements associated with their safety functions.

l Baltimore Gas and Electric Company's response to Generic Letter 89-13 was provided in Reference (b). In that response we outlined a program of surveillance and control techniques to significantly reduce the potential for Dow blockage as a result of biofouling (Task I - Saltwater Biofouling Program). We also outlined a test program for the safety-related heat exchangers within the Saltwater, Service Water and Component Cooling Systems to demonstrate that the required heat transfer capability can be met (TASK II Test Program). The iurpose of thLs letter is to inform you of changes which we have made to these two programs No e aanges have been made to Tasks III, IV, or V. /

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Mull 40360 KO104, 4/& 1 FOR \ \

ADOCK Co.sou217 I F FDR -

Document Control Desk January 6,1992

. Page 2 REVISIONS TO TASK ! SAlllWATER lilOFOULING PROGRAM in Reference (b) wc av:aitted to install a new chlorination (sodium hypochlorite) system to reduce biofouling in the Saltwater System. System installation was completed in April 1990. Following further study and operating experience with the Sodium liypochlorite System, we have found that the system is not effective in controlling heat exchanger tube blockage due to macrofouling (grass, mollusks, etc). Instead, we are now successfully controlling macrofouling in the Saltwater System by performing routine cleaning of the intake structure cavity walls, relocation of the ECCS cooler supply line penetration from the bottom of the 24-inch Saltwater header piping to the side of the piping, and removing unnecessary, stagnant water piping runs (dead legs) in the Saltwater System.

Operation of the Sodium Ilypochlorite System is no longer deemed essential to assure the capability of the Saltwater System to perform its safety function; it is being retained for possible use in controlling microfouling (e.g., algae) as an enhancement to heat exchanger performance. Its use can potentially reduce the frequency of Sen' ice Water IIcat Exchanger tube bulleting.

We originally stated that a new program would be established to ensure that Saltwater loops are properly placed in lay-up with biocide if the need arose. To date, cleaning of the intake structure cavity walls has significantly reduced the sloughing and intake of macrofouling debris and the need for lay-up with biocide has not arisen. We will continue periodic inspections of isolated portions of the system and re-evaluate the need for lay-up with biocide if significant macrofouling is observed in the future.

REVISIONS TO TASK 11 TEST PROGRAM NRC Generic Letter 89-13 recommended that a test program be conducted to verify the heat transfer capability of all safety related heat exchangers cualed by senice water. The Reactor Vessel Support Coolers and the Steam Generator Support Coolers are classified in the CCNPP Q-List as non-safety related (NSR) and do not perform any safety-related heat removal function. The Containment Penetration Coolers rnd LPSI Pump Seal and Bearing Coolers are safety grade components but only for the function of being a pressure boundary (PB) in a safety system. They do not perform a safety-related heat removal function. Because these coolers do not have a safetv-related heat removal function we have climinated them from this test procram.

Genotic Letter 8913 stated that an alternative to testing the heat removal capacity of safety-related hev . < changers is to either inspect or functionally test them. Functional testing verifies that a heat exchanger performs its intended function at operating conditions. This alternative is intended for those heat exchan;;crs for which the design heat removal rate cannot be quantified due to testing limitations. One possible testing limitation is measuring flow in small diameter pipes. The Iligh Pressure Cafety Injection (HPSI) Pump Seal and Bearing Coolers have a small diameter pipe which may prevent now measurement, if the pipe diameter of these coolers does prevent now measurement, we may conduct a functional test instead of testing their heat removal canacity.

Attachment (1) contains an updated version of the Heat Exchanger Test Program. Page 4 of this attachment reflects the modifications to the program.

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Document Control Desk January 6,1992 Page 3 i-Should you have any further questions regarding this matter, we will be pleased to discuss them with you.

Vety truly yours, d ') ^

I (,l GCC/LMD/Imd/bjd/dlm Attachment cc: D. A. Brune, Esquire  ;

J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mr Donald, Jr., NRC T. T. Wrtin, NRC A. G. Howe, NRC -

R.1. McLean, DNR J. H. Walter, PSC

'l Page1 of 7 -

A'ITACIIMENT (1) .

~

?

IIEAT EXCHANGER TEST PROGRAM I

IN TEST TEST PERIODICTEST SYSTEM HEATEXCHANGER PROGRAM TYPE FREQUENCY COMMEN'IS Component Cooling ' Y I I At least quarterly. Test Type II.B will also be performed prior to Heat Exchangers and following HX bulleting. Per the

S ILB ILB. At least once ' recommendation of GL 89-13, periodic test A' per Refueling Cycle. frequencies will be adjusted based on results

'L oftesting.

T

.W A- Service Water Y: I I Atleastquarterly. Test Type ILB will also be performed prior to T Heat Exchangers . . and following HX bulleting. P:r the E ILB ILB Atleastonce recommendation of GL 89-13, periodic test R per Refueling Cycle. frequencies will be adjusted based on results

of testing.

l

' ECCS Pump Room . Y. I Atleast once per BasM on the results ofinitial tests, the I 'S . AirCoolers IILA. ' Refueling Cycle. appropriate periodic test type will be Y or selected. Per the recommendation of GL 89-13, 4

~S..

IILB periodic test frequencies will be adjusted .

t . T .; based on restas ef tecting.

i E'

M i- Intake Structure N- -. -

These coolers do not perform a safety-related -

i . Air Coolers function. Saltwater flow is isolated on Sdety 3

InWien Actuation Signal f

i t

4 i

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

4 Page 2 or7 ATTAC11 MENT 0) .

11 EAT EXCIIANGER TEST PROG 8' AM IN TEST TEST PERIODICTEST SYSTEM HEAT EXCHANGER PROGRAM TYPE FREQUENCY COMMENTS i Containment Air Y III.A.

• S Coolers or E IILB R

V I Spent Fuel Pool Y ILB.

• Periodic testing will only be conducted ifit C Cooling Heat Exchangers is shown that a system wide corrosion induced E fouling problem exists.

Diesel Generator Coolers Y ILA W Main Turbine Lube N - -

A Oil Coolers T

E Main Feed Pump Turbine N -

R Lube Oil Coolers l

EHC Oil Coolers N - -

'Ihese HXs do not perform a safety function. '

Service Water flow to these ILXs is isolated on a S SafetyInjection Actuation Signal.

Y S Generator / Exciter N - -

T Air Coolers E

M Stator Liquid Cooling N - -

Heat Exchangers (U-1)

Hydrogen Seal Oil N - -

Coolers (U-2)

Page3 of 7 i

4 ATTACIIMENT (1) ,

i IIEAT EXCIIANGER TEST PROGRAM IN TEST TEST PERIODICTEST

. SYSTEM HEAT EXCHANGER PROGRAM TYPE FREQUENCY COMMENE Aux Feedpump Room ^ N - -

S Air Coolers - i E

, R Isophase Bus Duct Coolers N .- -

V I- I Condenser Air Removal N - -

i

. C Pump Seal Coolers .. .

. .E' '

Waterbox Priming. N - -

Pemp Seal Coolers i

.- W Condensate Booster Pump N -- -

These HXs do not perform a safety funcien.

i: A Lube Oil Coolers Service Water flow to these HXs is isolated on T a Safety Injection Actuation Signal.

. E Instrument and Plant N - -

j. .R Air Compressor Coolers Turbine Plant Sample iN - -

Coolers i i :- 3

, Y . M/U Demin Vacuum N - -

S Pump Cooler (U-1) i- T

.E' N2Compressor After . N - -

l< M Coolers (U-1) ,

i Steam Generator Blowdown N - -

HX does not remove heat from safety-related '

l Recovery System Heat - system / component. HX is safety rela:cd for -

,- Exchanger pressure beandary purposes only.

4 I i' i

I _

< ..- ,.-- , -- , ,m .. . - . . . . _ , . - .

A

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Page 4 of 7 A'ITACllMENT (1) .

IIEAT EXCIIANGER TEST PROGRAM IN TEST TEST PERIODICTEST SYSTEM IIEATEXCIIANGER PROGRAM TYPE FREQUENCY COMMENTS Shutdown Cooling Y - ILB. *

• Periodic testing will not be performed unless it C Heat Exchangers is shown that a system wide corrosion induced O fouling problem exists.

M.

P IIPSI Pump Seal & Y IV.B. *

• Periodic testing will not be performed unless it O Bearing Coolers is shown that a system wide corrmion induced N fouling problem exists. Initial tc4 ting will E verify adequat- component cooling flow and the N bearing and seal cooler temperatures can be T maintained below the design limit.

LPSI Pump Seal & N - - 1 C Bearing Coolers O These Heat Exchangers do not perform a O Containment N - -

safety-related function. They are safety L Penetration Coolers  ;.: lated for pressure boundary purposes only.

I. Main Steam N Main Feedwater G Letdown RCSample r S/G Blowdown S

Y Reactor Vessel N - -

S Support Coolers These Heat Exchangers do not perform any T safety-related heat removal function. They '

E_ S/G Lateral Support - N - --

are classified as non-safety related.

M - Coolers

4

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Page 5 of 7 NITACIIMENT (1) .

IIEAT EXCIIANGER TEST PROGRAM IN TEST TEST PERIODICTEST 4 SYSTEM HEAT EXCHANGER PROGRAM TYPE FREQUENCY COMMENTS I

C Reactor Coolant N - -

O Waste Evaporators M

P Control Element Drive N - -

These IIXs perform no safety-related function.

O Mechanism Coolers Component Cooling flow is isolated on N Containment Isolation Signal.

E Reactor Coolant Pump N -- -

N Seal and Lube Oil Coolers T

Reactor Coolant Drain N - -

Tank. Heat Exchangers C

O Letdown Heat Exchanger N - -

O L Waste Gas Compressor - N - -

I Coolers N

G RCW Degasifier Vacuum N - -

These HXs perform no safety-related function.

Pump Coolers They are classified as safety related for '

Component Cooling System pressure boundary S. NSSS Sample Coolers N g- -

purposes only.

i Y RC Sample  :

S SG Blowdown Sample T MWS Sample E

M Post Accident Sample N - -

System Cooler

I' age Gof 7 ATTACIIMENT (I) .

IIEAT EXClIANGER TESTI'ROGRAM INTEST TEST PERIODlCTEST SYSTEM IIEAT EXCIIANGER PROGRAM TYPE FREQUENCY COMMEN"IS CCS Gas Analyzer Sample N - -

OOY Coolers MOS These HXs perform no safety selated function.

PLT Hey are classified as safety related for OI E MWS Heat Exchanger N -- --

Component Cooling System pressure boundary NNM purposes only.

EG N

T S/G Blowdown RAD Monitor N - -

Sample Cooler 4

4 1

e

' Page 7 of 7 ATTACIIMENT (2)

IIEAT EXCllANGER TEST PROGRAM TEST TYPES

1. Monitor av - -ling water now and inlet and outlet temperatures for all affected heat exchangen , s of t ution in which cooling water is flowing through the heat exchange, 't .

..caem, erhy that the cooling water temperatures and Dows are within desip ' . Niorn of the measurement. The test results from periodic testing shoulo i ~

that flow blockage or excessive fouling acetimulation does not exist.

II.A. Perform functional m. s schonger operating, if practical, at its design heat removal rate to verify u . panni r:. remperature and flow compensation should be made in the calculations to adjust the rafts of the design conditions. Trend the results, as explained above, to monitor degradation, ll.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 Dow and temperature.

Ill.A Perform efficiency testing with the heat exchanger operating under the maximum heat load -

that can be obtained practically. Test results 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.

III.B If it is not possible to test the heat exchanger to provide statistically significant results (ior example, if error in the measurement exceeds the value of the parameter being measured),

then

1. Trend test results for both the air and water flow rates in the heat exchanger.

2. Perform visualinspections, where possible, of both the air and water sides of the heat exchanger to ensure cleanliness of the heat exchanger.

IV.A. If plant conditions 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.B. 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 periodic 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 a : -beduled.

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