ML20070D539

Provides Final Response to GL 89-13, Svc Water Sys Problems Affecting Safety-Related Equipment

ML20070D539
Person / Time
Site:	Calvert Cliffs
Issue date:	06/30/1994
From:	Denton R BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-13, TAC-M73978, TAC-M73979, NUDOCS 9407080176
Download: ML20070D539 (10)

Text

'

ftom n s IL lhs sm Italtirnore Gas and 1:Irctric Compmy Yurl'rt5ident Coin'11 CIWs Nucian l'us ucr I'lant Nw It or I no r n "'3" ("I" (I'N' I'"' 5 "'"5 Imin. Manland 20157 1 4 to $Wnw 1 tt 445$ la al 410 lrgo44$$ llultimore June 30,1994 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk SUllJECT: Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50 317 & 50 318 Final Response to Generic Letter 8913, "Senice Water System Problems AfRflip23afrudchted.listipment"ITAGps. M73978 anO173979)

ItEFEllENCES: See Attachment (2)

NRC Generic Letter (GL) 8913 outlined concerns regarding the safe operation and maintenance of open-cycle cooling water systms and identified several recommendations associated with ensuring proper heat transfer capability of their components. For Calvert Cliffs Units 1 and 2, the open-cycle, cooling water system in the scope of GL 89-13 is the Saltwater System.

Due to the large amount of correspondence describing our plans and actions to address the GL, the status of our actions may be unclear. Therefore, Attachment (1) to this letter provides the status of the five tasks outlined in the original response (Reference b). Attachment (1) supersedes all previous correspondence on GL 8913 and all commitments made to address GL 8913 issues.

Should you have any further questions regarding this matter, we will be pleased to discuss them with you.

Very truly yours, s

[ ] ~

\

RED /JMOldlm Attachments: (1) Status of Actions for Generic Letter 8913 (2) Generic Letter 8913 Correspondence Chrenological List i

9407000176 940630 0 1 l PDR ADOCK 05000317 i l P POR i

. . . I

+

Document Control Desk June 30,1994 l' age 2 cc: D. A. Ilrune, Esquire J. E. Silberg. Esquire M. K. Iloyle, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC P. R. Wilson, NRC R.1. McLean, DNR J. II. Walter, PSC t

. A1TACilSIENT (1)

STATUS OF ACTIONS FOR GENERIC LINTER 89-13 SERVICE WATER SYSTEh! PROllLEhlS AFFECTING SAFLTY RELATED EQUIPhlENT ,

5

1. TASK 1 - sal,TWATER IllOFOUI.ING PROGRAM e

The purpose of TASK 1 was to implement and maintain an or. going program of surveillance and control techniques to significantly reduce the incidence of flow blockage problems as a result of biofouling in open cycle systems. All activitics to address TASK I have been completed as described Lelow:

A. Repetitive maintenance tasks have been developed to ensure the intake Structure is cleaned and inspected on a pericdic basis.

11. Procedures are in place to ensure that infrequently-used, safety related Salts ter (SW) loops are flushed routinely. Flow through these loops is monitored monthly and afler debris-causing events II. TASK 2 - TEST PROGRAM FOR SAFETY-REl,ATED IIEAT EXCilANGERS The purpose of TASK 2 was to conduct a test program to verify the heat transfer capability of all safety-related heat exchangers (llXs) cooled by the SW, Service Water (SRW) and Component Cooling (CC) Systems (i.e., closed- and open-cycle systems).

A. Closed-sycle Initial Test Progam

• lhe goal of the closed-cycle test program was to determine if the quality of chemistry control programs has been sufficient to conclude that testing of closed cycle, safety-related ilXs under the scope of Generic Letter (GL) 8913 is not necessary. In the original response, we stated that closed-cycle systems would be removed from the scope of the GL 89-13 test program if none of them exhibited fouling caused by sys'em-wide corrosion.

%crefore, if no such fouling was identified in these systems, then the adequacy of chemistry control programs over the entire operating history of the plant was established.

The initial test activities included testing some IIXs and inspecting others. From the results of the initial test activities detailed in References (h) and (j), it was concluded there was no system-wide, corrosion-induced fouling in the closed-cycle systems, and confirmed that the closed-cycle llXs adequately transfer heat. They have been removed from the scope of our GL 8913 test program. The results arc shown below:

1

ATTACllMENT (1)

STATUS OF ACTIONS FOR GENER!C LI" ITER 89-13 SERVICE WATER SYSTEM PROllLEMS AFFECTING SAFETY-RELATED EQUIPMENT l

13. C]pigd-Cycle iigat.fiqban2C.[11C11.;md. InspsqtioMcsgJh Closed-Cycle IIcat Exchanger Test / Inspection Repits Containment Air Coolers Type Ill.B All coolers tested satisfactorily and all coolers were cleaned.

Spent Fuel Pool Cooling IlXs TvpcII.B All coolers tested satisfactorily.

Emergency Diesel Generator Type ll.A No.1I EDO Jacket Water and Air (EDG) Coolers Coolant ilX tested satisfactorily. All EDG coolers are inspected at 18-month intervals.

Shutdown Cooling IIXs Type ll.B /.11 coolers tested satisfactorily.

liigh Pressure Safety injection Type IV.13 (oolers for No.12 were flow-tested (IIPLI) Pump Seal and Bearing satisfactorily. Coolers for No. 21 were Coolers inspected.

C. Opsn-Cycig Initial Testhegana

%c goal of the open-cycle program was to determine the heat removal capability of systems that are cooled by Chesapeake Bay (i.e., raw) water. There are three groups of IlXs in open-cycle systems - SRW llXs, CC IIXs and Emergency Core Cooling System (ECCS) pump room air coolers. From the results of the initial test activities, it was concluded that the open-cycle llXs are designed and maintained such that their safety-related heat removal requirements are satisfied. Our conclusion is based on the results of completing the initial test activities as indicated below:

1. SRW IIcat Exci anggrj As described in Reference (h), difficulties were encountered with establishing sufficient heat load (i.e., appropriate plant conditions) to conduct valid tests of the Unit 1 SRW llXs during the 1992 refueling outage. A valid test has reasonable uncertainties in comparison to its acceptance criteria. As described in Reference (j), it was decided there was no benefit to performing initial tests or; the Unit 2 SRW !!Xs prior to comple ing significant modifications that would be installed during the spring 1993 r'.iueling outage. He modifications included replacing most concrete-lined nb witn mbber-lined pipe, modifying pipe runs and diameters where possible, and improving ixations for installing test equipment.

Additionally, similar to the Unit i SRW llXs, a valid test of the Unit 2 SRW IIXs requires suflicient heat load. For both of the Unit I and 2 SRW HXs, initial testing was performed afler they were cleaned by quarterly tube bulleting. The results of the tests were reviewed and determined to be valid. The HXs were able to remove the required amount of accident heat load for the highest recorded bay temperature (i.e.,85 F).

2

m ATTACIISIENT m STATUS OF ACTIONS FOR GENERIC LITTER 89-13 SERVICE WATER SYSTEM PROllLEMS AFFECTING SAFETY-RELATED EQUIPMENT in LER 50-317/93-007 (Reference 1), BGE reported that the results of thermal performance tests performed in fall 1993 indicated that the SRW llXs may not have been capable of meeting their intended safety function during the most limiting design basis requirement for bay temperature, (i c.,90*F). The original design calculation assumed minimum SRW flow was the limiting case. When maximum SRW design now rate to the CACs is assumed, heat is transferred from containment to the SRW System at a faster rate. This causes higher SRW temperatures than previously calculated, with the result being higher EDO temperatures. Since that report, it was concluded that the plant was safe in the past based on the following:

> the bay water temperature has never exceeded 85'F; and,

> the EDO vendor (Fairbanks Morse) reviewed the worst-case transient and concluded that EDG performance is not impacted.

To provide additional assurances of SRW llX heat removal capability for maximum expected bay temperatures, How control valves were installed for the CACs and SW pump differential pressure indication was improved (Reference m).

These modifications have been credited in re >idons to plant operating instructions.

2. CmnenLQlo igJilegt fischangey _

Due to an unscheduled shutdown just prior to the 1992 Unit I refueling outage, the Unit I CC IIXs could not be tested during the cooldown es scheduled.

Reference (h) describes difficulties associated with performing a valid test of the Unit 1 CC llXs due to insufficient heat loads. Specifically, the test was invalid because SW Dow had to be reduced to a level that maintained the CC water teniperature at 95'F so that the controlled bleed-off temperature for the Reactor Coolant Pump Seals did not fall below 110 F. If the Unit I test could have been performed during the plant cooldown, we expect that we could have met these requirements and also had sufficient SW Cow to perform a valid test.1-lowever, since the EPRI guidelines for IIX testing (Reference k) are based on steady-state cenditions, we had an additional concern that we would have difficulties achievir.g the required steady-state criteria during a plant cooldown. Therefore, in Reference (h), we stated that we would develop and validate a method to account for transient ilX conditions that exist during a plant cooldown (i.e., transient test).

During the cooldown for the 1993 Unit 2 refueling outage, both a standard and a transient type of test were performed on the Unit 2 CC llXs. When the data was analyzed, it was concluded that both tests had met the criteria of the EPRI guidelines. The results of the transient test were essentially identical to those of the standard test. Ilowever, since the cost of pe hrming the transient test was significantly higher than the standard test, BGE ducs not plan to perform it in the 3

. A1TACllMENT (1)

STATUS OF ACTIONS FOR GENERIC Li~lTER 89-13 l SERVICE WATER SYSTEM PROllLEMS AFFECTING SAFL'IT-RELATED EQUIPMENT future, in Reference 0), when we reported that the Unit 2 CC llXs had been tested to conclude that they have adequate heat transfer capability, we did not srecifically state which type of test was used.

1 During the cooldown for the 1994 Unit I refueling outage, initial testing was l performed again on the Unit 1 CC IIXs. These tests did not meet the EPRI l guidelines even though test instrument locations were optimized for the existing system configuration. During the outage, thermal wells were installed. They should improve the ability to perform valid thermal performance tests in the i future.

For the following reasons, we have concluded that the Unit 2 CC llX test results are applicable to the Unit I CC liXs, and that the initial test program for the CC llXs is complete:

> their design and construction are identical; t

> the raw water in their open-cycle sides is identical;

> the chemistry control program for the water in their closed-cycle sides is identical;

> based on other plant activitics, there is no evidence of fouling in closed-cycle systems, i

> their maintenance and testing programs are identical; and,

> they are operated identically.

3. ErnergnqnCortCoglintSystemBminRoom Air Cal _ers In References (h) and G), we reported that the initial testing for the Unit I and 2 air coolers had been performed satisfactorily.

D. Continuina Test Prograrn <

Based on the results of our Open and CloscGCycle initial Test Programs, our GL 8913 Continuing Test Program only includes the SRW, CC and ECCS IlXs. We have established a continuing test program to verify the thermal performance of these llXs.

4-p --wy-g >e.- w. -- y yhg .g-r,-y-wy,,--m.mwy,.y- w.7w,p.,g,--a.7,,,-,y .-yy,-, g-w--- ,,---y, ,.-- --

~ _... .. _ . - . - . . - ~ . - - . . - - - . - - . _ ... - _.- - - - .-. _ - -.

A1TACllMENT (1) 4 STATUS OF ACTIONS FOR GENERIC LETTER 89-13 SERVICE WATER SYSTEM PROllLEMS AFFECTING SAFETY RELATED EQUIPMENT t

111. TASK 3 - INSPECTION AND MAINTENANCE PROGRAM The purpose of TASK 3 was to establish a routine inspection and maintenance program for the SW piping and components to ensure that corrosion, crosion, protective coating failure, silting and biofouling cannot degrade system performance. All planned actions to address TASK 3 have been completed as described below:

A. Differemial pressure across the SRW llX is momtored twice per shift The SRW llXs and the CC llXs are bulleted quarterly, f it The program for cleaning and inspecting SRW, CC and ECCS IlXs is established. It will be revised as necessary based on the results of plant maintenance and testing activities.

Recommendations from System Engineering, based on their monitoring activitics, arc also r used to establish appropriate cleaning and inspection frequencies. New technologies will be incorporated as necessary.

C. The piping ultrasonic thickness inspection program has been reviewed and revised.

D. An underground piping inspection program has been established.

I V. TASK 4 - 1,1 CENSING llASIS REVIEW i

' Die purpose of TASK 4 was to confirm that the SW, SRW and CC Systems will perform their intended function in accordance with the liccnsing basis for the plant. All planned actions to address TASK 4 have been completed as described below:

A. Sys'em hydraulic and ilX models have been developed. The software was validated by duplicating a number of plant specific hydraulic calculations and comparing the results to the original calculations. System models were validated by comparison to actual plant data. The models have been used to evaluate a variety of flow cases, corresponding to

- system responses to various demands, including associated single failures. - Design basis ,

hydraulic and heat transfer calculations have been validated.

II. System drawings were reviewed and walkdowns were performed to ensure that the syste.ns -

were not vulnerable to single active failures.

V. 'I n * - SERVICE WATER SYSTEMS PROGRAMS REVIEWS The purposes of TASK 5 were to confinn that: 1) maintenance practices, operating and emergency j procedures, and training associated with the SW, SRW and CC Systems are adequate to ensure that safety-related systems will function as intended; and, 2) operators of this equipment will perform efTectively. All planned actions to address TASK 5 have been completed as described below:

5 a,-. .aw.-_, . , - - . , , .,-.,,,,...-n--.._-_n -

,,-.n , , , , , , , - - , - - , - - , , , - - , - - - ne.n,.,, -...nr -v r + oc,-,, v - -

NIT 4C1131f.NT m STATUS OF ACTIONS FOlt GENEltlC LE'ITElt 89-13 SEltYlCE WATEll SYSTEM l'ItOllLEMS AFFECTING SAFETY-ItELATED EQUll' MENT A. Under the Prcwedure Upgrade Program, numerous technical procedures associated with operating, testing and maintaining SW, SRW and CC Systems have been revised to enhance human factors and technical accuracy. These include Abnormal Operating Procedures, Operating instructions, Surveillance Test Procedures and Chemistry Procedures. Ruisd Wintenance Procedures inchide procedures associated tutn ricaning IlXs, overhauling pt.:r,rs, pipe repair, vahr repair, component cleaning and component inspection.

II. Site administrathe piocedures require that all plant modifications and changes to both administrative and technical procedures must be evaluated to dete mine if training must bc __

conducted prior to their implementation a,

P 6

- . . .. . - . - - _ . - . - - . . . _ . - - . - - - . . . . . .-. -~

ATTACllMENT 4)

GENERIC LETTER 89-13 CORRESPONDENCE CI'RONOLOGICAL LibT

REFERENCES:

(a) Senice Water System Problems Affecting Safety-Related Equipment (Generic Letter 8913), dated July 18,1989 (b) Letter from Mr. G. C. Creel (BGE) to NRC Document Control Desk, dated January 29, 1990, Response to Generic Letter 8913, "Senice Water System Problems Affecting Safety Related Equipment" (c) Senice Water System Problems AfTecting Safety-Related Equipment  ;

(Generic letter 89-13, Supplement 1), dated April 4,1990 (d) Letter from Mr. D. G. Mcdonald, Jr. (NRC) to Mr. G. C Creel (BGF),  !

dated April 27,1990, NRC Generic Letter 89-13, "Senice Water System l Problems Affecting Safety-Related Equipment," Calvert Cliffs Nuclear  !

Power Plant - Unit 1 & 2 (c) Letter frorn Mr. G. C. Creel (BGE) to NRC Document Control Desk, dated January 6,1992, Revised Response to NRC Generic Letter 89-13 "Semice Water System Problems Affecting Safety Related Equipment" (TAC Nos. M73978 and M73979) _!

l (f) Letter from Mr. D. G. Mcdonald (NRC) to Mr. G. C. Creel (BGE), dated February 6,1992, Updated Res9anse to NRC Generic Letter (GL) 89-13, j "Senice Water System Problems Affecting Safety-Related Equipment,"

Calvert Cliffs Nuclear Power Plant - Unit I & 2 (g) 1xtter from Mr. G. C, Creel (BGE) to_ NRC Document Control Desk, dated August 4, 1992, Revised Testing Schedule; NRC Gener;c Letter 89-13, " Service Water System Problems Affecting Safety-Related ,

Equipment"(TAC Nos M73978)

(h) Letter from Mr. G. C. Creel (BGE) to NRC Document Control Desk, dated September 16, 1992, Summary of Completed Actions; NRC Generic Letter 89-13, "Senice Water System Problems Afreeting Safety- .

Related Equipment"(TAC Nos. M73978 and M73979) 4 (i) Letter from Mr. D. G, Mcdonald, Jr. (NRC) to Mr. R. E. Denton (BGE),

dated December 9,1992, Generic Letter (GL) 89-13. "Senice Water System Problems AtTecting Safety-Related Equipment," - Calvert Clifts

+

Nuclear Power Plant - Unit I & 2 (TAC Nos. M73978 and M73979) l j (j) ' Letter from Mr. R.' E. Denton (BGE) to NRC Document Control Desk, dated July 12, 1993, Summary of Completed Actions; NRC Generic Letter 8913 "Scnice Water System Problems Affecting Safety-Reitted - .

Equipment"(TAC Nos. M73978 and M73979) l 1

. NITACll%1ENT (2)

GENERIC 1IIITER 89-13 CORRESPONDENCE CilRONOLOGICAL LIST llEIT.RENCES: (k) IIcat Exchanger Performance hionitoring Guidelines (EPGI NP-7552) (

(1) Letter from hir. C.11. Cruse (BGE) to NRC Document Control Desk, dated December 29,1993, Licensee Event Report 93-007, " Performance Tests Indicate Possibility of SRW llcat Exchanger Inoperability" (m) Letter from hir. C.11. Cruse (BGE) to NRC Document Control Desk, dated June 17, 1994, Reply to Request for Additional Information -

Service Water System Operational Performance Inspection f

2 I u i . . . . _ . . .. ._ _ . _ . _. _ _ . _ _ _ _ _ _ _ _ _ . _ _ _ _ . _ _ . _ _ _ _ _ _ _