ML20006C158

Forwards Response to Generic Ltr 89-13 Re safety-related Open Svc Water Sys.Instruments in Place on Component Cooling Water Sys/Auxiliary Component Cooling Water Sys HXs Which Connect to Plant Monitor Computer

ML20006C158
Person / Time
Site:	Waterford
Issue date:	01/29/1990
From:	Burski R LOUISIANA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-13, W3P90-0207, W3P90-207, NUDOCS 9002060409
Download: ML20006C158 (10)

Text

l

,_m l . Louisiana Power & Light Company

-- g 317 Baronne Street P. O. Box 60340

• New Orleans. LA 70160-0340

. Tel 504 595 2005

- R. F. Durahl

^ Nuclear Galety & Regulatory Attaire-Manapor W3P90-0207 A4.05 QA January 29, 1990 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555

Subject:

_ Waterford 3 SES Docket No. 50-382 License No. NPF-38 NRC Geparic Letter 89-13 Gentlemen:

Generic Letter 89-13 reviews the regulatory requirements.applicabic to safety-related open service water systems at nuclear. power plants. The NRC' cites instances where service water systems cannot remove the amount of heat assumed in the safety analysis. Juch systems experience biological fouling.. erosion, corrosion, coating failure, and silt accumulation.

Consequently, the Eeneric letter asks licensees to commit to a plant.

specific program to upgrade their open service water systems and effectively combat biological fouling.

LP&L examined Waterford systems to determine which ones were within the scope of the generic letter. LP&L identified one system at Waterford as meeting the inclusion criteria of Generic Letter 89-13 -- Auxiliary Component Cooling Water (ACCW). The ultimate heat sink at Waterford is a unique wet and dry tower arrangement. ACCW can transfer heat from either the Component Cooling Water System, or in unusual cases the Essential Chillers, to the wet cooling tower (which includes a self contained pair of basins with a controlled make-up source).

The attachments to this letter address each action recommended by Generic Letter 89-13 for the ACCW system. As described herein, LP&L's program is already extensive and covers many of the issues raised in the generic letter.

t 8\

g2]{f{[$$O g2 An Entorgy Company .

P

ni ~

y '.'

~

-i

.g.

-W3P90-0207 NRC Ceneric Letter 89-13

-Page 2-LJanuary 29 1990

=If there are any.further questions please contact me or T.H. Smith at.(504)..

464-3127.

Very.truly yours,-.

. a RFB/SEF/ssi Attachments cet Messrs. R.D. Martin. NRC Region IV F.J. Hebdon. NRC-NRR D.L. Wigginton NRC-NRR -

E.L. Blake W.M. Stevenson

-NRC Resident Inspectors Office'-

l

[

o i

Y.

4

E ,

UNITED STATES OF AMERICA'

. NUCLEAR REGULATORY COMMISSION In the matter of )

) .

Louisiana Power & Light _ Company ) Docket No. 50-382 Waterford 3 Steam Electric Station )

AFFIDAVIT R.F. Burski, being duly sworn, hereby deposes and says that he is

. Nuclear Safety and Regulatory Affairs Manager of Louisiana Power 6 Light Company; that he is duly authorized to sign and file with the Nuclear -

Regulatory Commission the attached response to NRC Generic Letter 89-13; that he is familiar with the content thereof; and that the matters set.

forth therein are true and correct to the best of his knowledge, information and belief.

fw R.F. Butski Nuclear Safety & Regulatory _ Affairs -

Manager STATE OF LOUISIANA)

) as PARISH'0F ORLEANS )

Subscribedandsworntobeforeme,aNotaryPub{$nandforthe-Parish

,,' ,;n 1.0<v-and State above named this- eM9/L day of ' ,

1990. p /-

. A [ qfh.

Notary Public (/,;

My Commission expires /dtku .

/ 0 l

Y

-n

..- Attcchment to W3P90-0207 Page 1 of 7  :

l CENERIC LETTER 89-13  :

ACTION I Action I asks for an on-going program to reduce flow blockage problems l caused by biofouling in the safety-related open service water system (i.e., ,

Waterford's auxiliary component cooling water system). The program may control chemistry, control intake physical cleanliness, and inspect for i success by sampling-for organisme.

The auxiliary component cooling vater system (ACCW) is a wet cooling: tower system. Because this safety-related system contains open basins, it may be considered an "open"' service water system.. It employs demineralized water-for make-up.

The make-up water comes through demineralizero.-filters and a reverse osmosis unit. Its total organic carbon (TOC) content is,.thus, quite low.

LP&L stores it under nitrogen over-pressure and deoxygenates it..

.Therefore, organisms cannot grow in the stored make-up water.

The ACCW is never in aflay-up mode. LP&L'uses a phosphate-silicate based chemical corrosion inhibitor to maintain a low corrosion rate. pH is kept between 8 and 11 for the same reason.

LP&L monitors the ACCW basins for biological fouling by visual inspection as well as analysis of water for biological activity on a weekly basis.

When biological activity exists. LP&L injects a non-oxidizing biocide into the system. LP&L does not regularly add biocide to the system because organisms can develop immunities to the biocide. Because'LP&L has found no flow blockage or clams, and monitors /takeo action when microbes are present in ACCW, LP&L considers the chemical control program to be' effective.

. Attcch: nt to W3P90-0207 Page 2 of 7 i

- GENERIC LETTER 89-13 ACTION 11 This action asks that licensees confirm adequate chemical controls on the primary (tube) side of the saf ety-related open service water system heat exchangers. A high quality primary side provides the basis for minimizing surveillances of the tube (component cooling water) side. With this assurance in hand, licensees need to perform a heat removal capacity check on the safety-related open service water system heat exchangers, i.e., the ,

auxiliary component cooling water heat exchangers. This check fulfills the requirement outlined in 10 CFR 50, Appendix B, i.e., a test program to ensure all structures, systems, and components perform satisfactorily in-service according to written tests (re Criterion XI).

The Waterford component cooling water system (CCW) forms the tube side of the two heat exchangers in the auxiliary component cooling water system --

the safety-related "open" service water system. CCW is a closed system '

that uses demineralized and deaerated water for make-up. LP&L adds a nitrite based corrosion inhibitor to the CCW water. Nitrite concentration is maintained above 500 ppm leading to less than 1.0 mils per year corrosion rate (according to the Calgon Company method). Further LP&L monitors CCW for biological activity on a weekly basis. If biological activity were present LP&L vould add a non-oxidizing biocide. Experience shows this program to be effective because there has been no evidence of CCW blockage.

Because LP&L has historically maintained high water quality in CCW, LP&L's response to this action concentrates on ACCW heat exchanger thermal performance.

LP&L tested the CCW and ACCW systems during initial plant startup. The pre-operational tests measured flows and balanced the system. The integrated startup tests verified the performance and heat exchanger capacity. These test results allow LP&L to confidently use vendor supplied information as a baseline from which'to judge heat exchanger performance in the future without reperforming the integrated startup tests.

LP&L already has instruments in-place on the CCW/ACCW Heat Exchangers which are connected to the Plant Monitor Computer (PMC). The PMC can be queried for inlet and outlet temperatures and flows on both the heat exchanger shell and tube sides (ACCW and CCW sides respectively). LP&L will develop a procedure to collect and trend the data from the PMC no less frequently than once per fuel cycle. That procedure will be in place before the end of the next refueling outage.

The collection of heat exchanger data from the PMC und the evaluation of that data will follow the recommendations in Enclosure 2 of Generic Letter 89-13. Simulation of design conditions is not practical but the results will be adjusted to design conditions according to Enclosure 2. The design heat transfer rates, heat transfer coefficients and efficiency will be compared to the baseline. The results will-determine the need for corrective action and will be trended to monitor for any degradation.

I .~

.- ~Attcch;;nt to' W3P90-0207 j Page 3 of 7' ,

GENERIC LETTER 89-13 ACTION III '

This action asks licensees to inspect the safety-related open service water -

system for erosion, corrosion, coating failures, silting, and biofouling.  ;

The' generic _ letter. notes industry experience where corrosion and erosion of . ,

system piping often progressed to a through-wall 11eak before detection.

The LP&i erosion / corrosion program for Waterford was thoroughly presented ,

in its supplemental response to Generic Letter 89-08 (re W3P89-1592, dated November. 17, 1989). . Components from auxiliary component cooling water -- +

the Waterf ord safety-related "open" service water system -- will be added ~i to that program before the start.of the next refueling outage. Those components'will,be inspected according to the established program.

In the meantime, Waterford design and programs eliminate or closely monitor 'l for problems with coating f ailures, silting, and biofouling. For instance,  !

the auxiliary component cooling water system (ACCW) piping is not coated internally; therefore, coating cannot fail. Furthcr, ACCW uses .

demineralized water for make-up; therefore, no silting problem can exist.

Lastly, LP&L monitors ACCW for biological activity as discussed in Action 1 l and selected sites for Asiatic Clama.

h l [

t l -f

-i I

i t

i i

l' I

t i

m.- -

. Att:chment to W3P90-0207 Page 4 of 7 GENERIC LETTER 89-13 ACTION IV This action asks for confirmation that license basis statements are implemented. Particular emphasis was placed on ensuring a single failure cannot eliminate all the safety-related functions that the open service water system needs to perform according to the Final Safety Analysis Report. Furthermore, the as-built system should already match the appropriate licensing basis documents, as confirmed by a recent (within the past two years) system walkdown.

LP&L conducted a review of most of these issues in preparing its Design Basis Document (DBD) for the component cooling water / auxiliary component cooling water system (CCW/ACCW). The DBD for CCW/ACCW addressed the following areas:

1. Verify the adequacy of the design to accomplish design basie-safety functions without relying on non-safety-related equipment.

2. Verify the adequacy of documentation supporting the above design.

3. Verify the correlation and consistency of design documents.

4. Verify the incorporation into the design of regulatory

, requirements, licensing commitments, and design bases as specified in the Final Safety Analysis Report and associated correspondence.

5. Verify the consistency of information between various design' groups and disciplines.

LP6L administrative corrective action controls provide the_ mechanism for j tracking and resolving problems uncovered during the DBD development. 1 The already pubidshed DBD describes the CCW and ACCW functions, design requirements, interlocks, interfaces, documented margins, accident analysis assumptions, drawings and documente applicable to the systems.- It also describes the CCW and ACCW component design requirements and specific equipment design. The DBD also addresses accident and normal operation.

The DBD collects the design information for the CCW and ACCW. It allows easy access to information required for evaluations and decisions. The DBD assists personnel in making decisions on plant modifications, providing background for securing future technical specification relief, documenting licensing commitments and design changes, and providing background information for 10 CFR Part 50, 550.59 determinations.

At the end of 1988, LP&L conducted a review of selected CCW/ACCW features in a-Safety System Functional Inspection (SSFI). The LP&L' corrective .

action program is tracking and resolving questions raised during the SSFI. -l l

p

. Attachment to W3P90-0207 Page 5.of 7 f- GENERIC LETTER 89-13 ACTION IV (Continued) e.

During and since initial' plant startup, LP&L has conducted numerous checks (e.g., construction,-turn over punchlist, functional testing, normal. system operation) which ensure ACCW was constructed correctly. Note, ACCW is a comparatively simple system with few active mechanica1Lcomponents.

LP&L is confident that the above information . verifies that this. system matches its FSAR description. To' fully address the intent of Generic letter 89-13. Action IV,.however, LP&L.will walkdown ACCW before the end of' the next' refueling outage. . The walkdown is to confirm that observable ACCW hardware features contained in the FSAR actually. exist in the' field.' The walkdown itself will not cause equipment disassembly for inspection.

Its results will be documented and-retained in appropriate plant records.

7..

L '

. Attatchsnt ' to

. . '-

• W3P90-0207 Page 6 of-7 GENERIC LETTER 89-13 ACTION V-l l-This action asks licensees to upgrade their maintenance, operating, and i emergency procedures and training related to the.. safety-related open service water system.

l' . .

The LP&L maintenance program for Waterford includes.135 routine tasks for the ACCW to ensure that adequate maintenance is being performed. A review directed at concluding this action will' covert.

1.. Checking that all components required to perform the saf ety l functica of the system have adequate preventive maintenance-performed on them.

2.- Ensuring that the procedures applicable for 'each ACCW tanA are- 3 adequate to perform the task {

l

3. Checking the frequency for each ACCW task to ensure that they are ..

performed at the correct interval.

l

4. Checking the corrective maintenance performed'in the past to l

determine if any ACCW components with recurring problems can be j better addressed through enhancements to preventive maintenance practices.

5. Ensuring that the environmental qualification requirements for. ij l- each ACCW component included in the Equipment Qualification 3 j.- "regram are adequate and that, where appropriate. there are ,

rourine tasks for. actions required to maintain ACCW' component j

!n,ironmental qualification.

l l LP&L wi13 complete these five items'before the end of the next refueling outage. j i

Maintenance personnel are required to complete General Plant Systems :j '

Training before being qualified to perform maintenance' at Unterford without supervision. CCW and ACCW are featured in one of the-coursellectures.

i In addition, mechanics require training on heat exchanger operation and.

maintenance as part of the Basic Mechanical Maintenance Training Program.. 4 Instrument and control (I&C) technicians and electricians receive training 'j on components that support these systems as part of their own Basic 160 and 1 Electrical Maintenance Training Programs. Separately,.the operations staff l reesives initial and continuing training on the CCW and ACCW. This tra;ning includes normal and off-normal system operation.

J

+

s

Attach 2:nt to W3P90-0207-Page'7 of,7 GENERIC LETTER 89-13 t ACTION V (Continued) i LP&L operators start the ACCW system up at least once per week using. i procedure OP-901-003 (manual operation) to allow a check of its water chemistry. _For this reason, LP&L believes special training on ACCW system-operation is unnecessary. Further, the system is operated continuously during the months of May to November, compensating for the naturally hot outside. temperatures. Control room staff routinely use operating '

procedures and training for ACCW and, thus, LP&L can show that operators of ,

the ACCW equipment perform effectively.

{

s s

s

.i r1 ts j