ML20096F031
| ML20096F031 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 05/14/1992 |
| From: | Jackson M COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-13, NUDOCS 9205200152 | |
| Download: ML20096F031 (6) | |
Text
_
A-Commonwealth Edison s
31 1400 Opus Place Downers Grove, Illinois 60515 May 14, 1992 Office of-Nuclear Reactor Replation U.S. Nuclear Regulatory ComnJ.3sion Washington, D.C.
20555 Attn:
Document Control resk
Subject:
LaSalle Statien Unit 2 Response to Generic Letter 89-13 HRC_Dacte_tlo1_50:314
References:
(a) NRC Generic Letter 89-13, dated July 18, 1989.
(b) M.H. Richter letter to the NRC dated January 29, 1990.
(c) D. Taylor letter to the NRC dated November 14, 1990.
(d) D. Taylor letter to the NRC dated June 7, 1991.
Dear Sir:
NRC Generic Letter 89-13 (Generic Letter) indicated that recent operating experience and studies bad raised concerns about service water systems in nuclear power plants.
The Generic Letter requested licensees to take actions which would ensure that their service water systems were in compliance with, and would be maintained in compliance with, 10 CFR Part 50, Appendix A, General Design Criteria 44, 45, and 46 and Appendix B.Section XI.
Additionally, the Generic Letter required a response which would confirm that each licensee had established programs to implement the recommended actions of the Generic Letter, or that equally effective actions had been pursued.
References (b) and (c) provided Commonwealth Edison's (CECO) response for Dresden, Quad Cities, Zion, LaSalle County, Byron and Braidwood Stations to Generic Letter 89-13.
Reference (d) provided the completed actions for LaSalle Station Unit 1.
The purpose of this-letter is to notify the NRC that all the actions committed to by CECO in response to Generic Letter 89-13 have been completed for LaSalle Station Unit 2.
The attachment to this letter outlines those actions taken.
Please direct any questions that you may have concerning this response to this office.
Rg
.espectf ly, Ano q
EO'
/' MA4LJ L4f77 88 Ma(ci.A.
J kson 4
oo Generic M ues Administrator a s:
Oo oo Attachment ng re -&
cc:
A.B. Davis - Regional Administrator, Region III V
No R. Elliot mject Manager - NRR Resident Ins
' tors - LaSalle ZNLD/902(22) 190133
LASALLE: STATION UNIT 2 RESPONSE to GENERIC LETTER P9-13~
0 4
GL 89-13 IleL11 Implement and maintain an ongoing program of survelliane and control
. techniques-to significantly reduce the incidence of flow blockage problems as a result-of biofouling.
CECcLACIl0RS The Service Hater Tunnel in the Lake Screenhouse is the source of water to LaSalle's essential service water systems, referred to as the Core Stanc'by Cooling-Systems (CSCS).
The Service Water Tunnel, which is common to both Units.1 and 2, receives its water supply form the CH pump Suction Bays through 6 separate-36 inch diameter pipes which connect directly to the CH Pump Suction Bays.
.Due to safety concerns regarding the inspections of the Service Hater Tunnel (ie. extremely turbulent water currents, zero visibility), LaSalle Station will not visually inspect the tunnel.
Due to the turbulent water currents in the--tunnel, sedimentation should not be a problem.
LaSalle Station is also chemically treating the Service Hater Tunnel with a blocide and silt dispersant. - It is expected that this chemical feed system will eliminate the need to inspect this portion of the Lake Screenhouse.
A surveillance is performed once per 18 months to monitor and chart the bottom of the Circulating Hater-(CH) Pump Suction Bays in the Lake Screenhouse.
By comparing the charted depth of the bottom of the CH pump Suction Bays to the known depth of;the bottom of the Lake Screenhouse structure, sediment and macroscopic _biofouling-accumulations are identified and copropriate-corrective actions'are taken.
The surveillance references the 1 foot sediment limit as
' specified in the LaSalle Technical Specifications.
The.CSCS cooling water screen bypass line has been inspected.
The re:ults f
showed acceptable levels of sedimentation with no evidence of biofouling or
(
corbicula.
LaSalle Station has installed a Chemical Feed System, in order to mi.:imize biofouling and silting in the Service. Water System. A biocide and silt d:3persant are injected into each of the six service water tunnel inlet pipes.
1 By treating.the entire Service Water Tunnel; the CSCS Systems, the Fire Protection System and the Non-Essential Service Water System will receive Chemical Treatment.
Initially, the Chemical feed System will be operated continuously to ensure that chemically treated water will always be drawn into the CSCS when they are started for surveillances or by auto start signals.
If inspections and
- testing of CSCS components show that biofouling_and microbiologically influenced corrosion-(MIC) can be controlled through the intermittent use of the biocide', LaSalle Station may pursue this option.
New procedures have been put in place or existing procedures have been revised to require-and document periodic flushing and flow testing of infrequently used or stagnant lines in the CSCS.
LaSalle-Station is in compliance with the Generic Letter to flush and flow test infrequently used CSCS Lines.
All applicable CSCS Lines are periodically flushed and flow tested in accordance with LaSalle Station surveillances.
-ZNLD/902(23)
4_
~
o
. y 0L89-lLIMIL11 Conduct a test program to verify the heat transfer capability of all safety.related heat exchangers cooled by service water.
The total program should consist of an initial test prc, gram and a periodic retest program.
CLco_. ACTIONS LaSalle Station has established a program to test (or inspect / clean) safety-related heat exchangers.
The heat exchanger testing procedures have
,been revised to correspond to the testing program outlined in Enclosure 2 of NRC Generic Letter A9-13.
Each heat exchanger test or inspection has been scheduled and will be performed at least once per 18 months.
the initial test or inspection of each Unit 2 safety-related heat exchanger has been performed in accordance witn the revised procedure.
The heat exchanger test and inspection results were satisfactory, t
y 4
m k_
b t
1
.ZNLD/902(24)-
l 1
l GLB9-1LIlDL111 Ensure by establishing a routine inspection and maintenance program for open-cycle service water system piping and components that corrosion, erosion, protective coating failure, sitting, and biofou'ing cannot degrade the performance of the safety-related system upplied by rarvice water.
The mainten:ne progra>> chould have at ichst the following purposes:
P i
A.
To remove excessive accumulstions of biofouling L
a erits, corrosion products, and silt; t
D.
To repair defective protective coatings and corroded service water system piping and components that could adversely affect performance of their intended safety functions.
RC0J1110HS The results of the Service Water System Evaluation Program concluded that the 1,asalle Station CSCS Service Hater System has no high flow locations susceptible to erosion.
As a result, LaSalle Station will not perform inspections of the CSCS Service Water Syrtem for high flow erosion.
Low flow iccations in the CSC'., service Hater System were identified, based on their susceptibility to corrosion.
The locations were inspected for wall thickness meai,urements and detection of silt.
The Unit 2 inspections were
- trformed during the Unit 2 refueling outage with satisfactory results.
9 F
ZNLD/902(25).
m g e y, n.w ~
w
,,,,vr,cy.,..,,.h,,
.+,,,,,,,,w-
.,,.gr.r~.
--,-..--_.m-.n------__.
)
Gk3hlLilUi.1X Confirm that the service water system will perform its intended function in i
accordance with the licensing basis for the plant.
Reconstitution of the design basis of the system is not intended.
This confirmation should include a review of the abili_ty to perform required safety functions in the event of failure of a single active c.omponent.
To ensure that the as-built system is in accordance w!;h the appropriatc licensing basis documentation, this should include recent system walldown inspections, i
CIC d C110MS A design review for each Safety-Related Service Hater System has ?,ren perfo med.
The design review consisted of the following five areas of stud,.
-System Configuration Review
-Single failure of Active Component Review 1
-field Verification of P&l0's
-flood Protection Review
-Pipe Support Review No open items were identified during the dasign review.
4 L
l ZNLD/902(26)
=
-,.---,-.-.-..,,-a.,:
_ _ _.. _. _.-. _. _ _.. _ _ - _.. _ _.. ~. -. _.. _ _. _ _ _ _ _ _ _ _ _.
L i
L e
GL 69-13..!KttV Confirm that the maintenance practices, operativ and emergency procedures and training that involves the service water system are adequate to ensure that safety-related equipment cooled by the service water system will function as intended and that operators of the equipment will perform effectively.
CECO.AC110tG Maintenance practices. tralning programs, and operating and emergency procedures have been evaluated to assure that the CSCS Service Hater Systems will function'an intended and that operators will perform effectively.
Results of this evaluation will be reviewed for their applicability at LaSalle o
Station.
i b
i e
I h
l-i ZNLD/CQ2(27)
. ~.
. ~
_ _..._ _. _,