ML20029A119
| ML20029A119 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 01/25/1991 |
| From: | Taylor D COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-13, NUDOCS 9102040144 | |
| Download: ML20029A119 (6) | |
Text
_ _ _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _
g Commonwealth Edison 1403 C.1us Place O.
Downers Grove, Illic.ois 00515 January 25, 1991 U.S. Nuclear Regulatory Commission j
Attn:
Document Control Desk Hashington, D."
20555 c
b.'
Dyron Station Units 1 and 2 u
Supplemental Response to Generic letter 89-13 NRC_DockeLNot 50-45LanL50-455
References:
(a) HRC Generic Letter 89-13, dated July 18, 1989.
(b) M.H. Richter letter to tbc NRC dated January 29, 1990.
(c) D. Taylor letter to the NRC dated November 14, 1990.
~
Dear Str:
s NRC Generic Letter 89-13 (Generic Letter) indicated that recent operating experience and studies had 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 'n 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 t..at each licensee had established programs to implement t.,e recommended actions of 1
the Generic letter, or that equally effective actions had been pursued.
Reference (b) provided Commonwealth Edison's response for Dresden, Quad Cities, Zion, LaSalle :ounty, Byron and Braidwood Stations to Generic letter 89-13.
The purpose of this i.'tter is to not'.
t'ic NRC that all the actions committed to by CECO in response to Generic Letter 89-13 have been completed
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for Dyron Unit 2 and systems common to Byron Units 1 and 2.
Attachment I outlines those actions taken.
Please direct any questions that you may have concerning this response to this office.
Respectfully, D.L. Taylor Generic Issues Administrator ettachment
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A.B. Davis - Regional Administrator, Region III g(d A. Hsia - Projectm Manager - NRR
,;3 Resident inspectors - BY
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AIIACHMEMLl GLB9-lLI tem _I:
Implement and maintain an ongoing program of surveillance and control techniques to significantly reduce the incidence of flow blockage problems as a result of blofouling for open cycle service water systems.
Ceco _Ac11ons A new procedure, was written and approved to require and to document an annual underwater inspection of the River Screen House intake structure and the Essential Service Water Cooling Tower basins.
This inspection was completed on November 15, 1990.
As noted in Reference (c) continuous injection of Sodium Hypochlorite is currently being performed into the Essential Service Hater Cooling Tower
- Basins, New procedures have been put in place or existing procedures have been modified to require and docunient periodic flushing of infrequently used or stagnant linee in the Essential Service Heffr system.
The River Screen House and the Essential. Service Hater Cooling Tower bcsins have been sempled for the presence of macrobiological infestation.
The results showed acceptable macro fouling with no asiatic clams present.
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GL_B9-13_ Item _I1:
Conduct a test program consisting of an initial test program and a periodic retest program to verify the heat transfer capability of all safety-related heat exchangers cooled by service water.
CECO-_Ac1Lons The Essential Service Hater system has been determined to be the only safety related open cycle cooling water system at Byron Station, however closed cooling water systems were also studied.
The study 'ndicated that the closed cycle cooling water systems have been acceptably maintained and controlled and therefore testing and inspection of the closed cycle cooling water cycle systems was not performed.
Safety related heat exchangers which
-fall under the requirements of GL 89-13 have been Identified and tested or inspected according to CECO's commitments to the Generic Letter for Unit 0 and Unit 2.
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Gk.89:13_ Item III:
Establish a routine inspection and maintenance program for oper. cycle service water system piping and components so that corrosion, erosion, protective coating failure, silting and biofouling cannot degrade the performance of the safety-related systems supplied by service water.
CECO _Ac t1ons High flow and low flow piping locations were identified and incorporated into Station procedures, which determine whil thinning problems by ultrasonic inspection at the specified locations.
The specified locations were selected based upon their susceptibility to high flow erosion or low flow fouling and corrosion.
The Unit 2 procedure was performed during the Unit 2 refueling outage with satisfactory results.
Corrosion rates are monitored continuously to identify adverse trends, untnou n
GLB9-13_.l_tenLLV:
Confirm that the service water system will p3rform its intended function in accordance with the licensing basis for the plant.
This confirmation should inclede a review of the ability to perform required safety functions in the event of failure of a single active component.
To ensure that the as-built system is in accordance with the appropriate licensing basis documentation this should include recent system walkdown inspections.
CEColc1]om This review has been performed by Commonwealth Edison.
No single active failure vulnerabilities were identified.
However, the single failure analysis discussed in the UFSAR will be enhanced to include discussion of system pumps and valves, During as-built verification walkdowns five discrepancies were identified Detween the as-built and the as designed condition of the plant.
The discrepancies were evaluated and corrective action has been taken and each discrepancy has been resolved.
S til.D7 0i) /15
GLB9-ILLtem Y:
Confirm that maintenance practices, operating 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 this equipment will perform effectively.
CECO Tttions Procedures are continuously validated by use.
The two year review process required by an administrative procedure ensures that all procedures are correct, accurate and will result in operation of all systems in accordance with their design intent.
Any change due to modification of the service water system is controlled by BAP 1610-8 and requires training manuals l
and procedures to be updated to reflect the as-build condition.
Maintenance practices are controlled through station procedures and therefore receive the same level of review.
.Essent'ol Service Hater training is performed in accordance with the INPO accredited initial and requalification license training program.
In 1989 this program consisted of both classroom and simulator scenarios including SX system component failures. As part of the accrediation process, future requalification training on SX will be performed based on industry events, station needs and regulatory requirements.
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