ML20003E952

From kanterella
Jump to navigation Jump to search
Forwards Updated LER 81-007/03L-1.Detailed Event Analysis Encl
ML20003E952
Person / Time
Site: Millstone Dominion icon.png
Issue date: 04/08/1981
From: Mroczka E
NORTHEAST NUCLEAR ENERGY CO.
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20003E954 List:
References
MP-2-4646, NUDOCS 8104170549
Download: ML20003E952 (2)


Text

.

c

. LE3[1TTU3/*!E'L' Cf'ETE.UET[!!i P.O. 00X 270

\  !.ll T.'l'l'T/,: ,'C:L.,,

. mnu ono. cowxcneur moi

(*"""

g

. W. . . :::;;':.'. l. :',,'.' ,

Ap'ril 8,1981 HP-2-4646 Mr. Boyce H. Grier Director, Region 1 5 m Office of Inspection and Enforcement \

U. S. t;uclear Regulatory Commission f 631 Park Avenue 6 i King of Prussia, Pennsylvania 19406  ; (2t Facility Operating License No. DPR-65 E, %/lpg1 G 1987g

Reference:

    • /h Docket flo. 50-336 Reportable Occurrence R0-50-336/81-7/3L-1 E g i.
  • #y

Dear ftr. Grier:

This letter forwards update Licensee Event Report 81-7/3L-1 subnitted pursuant to itillstone Unit 2 Appendix A Technical Specifications, Section 6.9.1.9.b, conditions leading to operation in a degraded mode permitted by a limiting condition for operation. An additional three copies of the report are enclosed.

- 'Yours truly, NORTHEAST I;UCLEAR ENERGY C0!iPAtlY

/W Ga./ .

E. . 11roczka  !

Station S;perintendent Millstone fluclear Power Station EJM/JDB:mw

Attachment:

LER 81-7/3L-1 cc: Director, Office of Inspection and Enforcement, Washington, D.C. (30)

Director, Office of flanagement Information and Program Control, Washington, D.C. (3)

U. S. fluclear Regulatory Commission, c/o Document Management Branch, Washington, D.C. 20555

  • ~

810.41705'/7 y

ATTACitMENT LER 81-007/031-1 Millstone Unit 2 Docket No. 05000336 Cause Description and Corrective Action An excessively corroded sacrificial zinc anode caused the leakage. This. '

was replaced and the remaining zincs were inspected and replaced as necessary.

Prior to October 22, 1980, the D/G heat exchangers were inspected and cleaned of mussels on a weekly planned maintenance schedule. The zines were inspected and replaced as necessary during this activity but were not documented as part of the activity. After October 22, 1980, weekly inspection and cleaning of the D/G heat exchangers was discontinued due to addition of strainers in the service water inlet lines. This lack of inspection allowed the corrosion of the zincs to go unnoticed until the leak occurred.

To determine an appropriate schedule for inspecting the zincs, weekly inspection has been added to the planned maintenance schedule. This will be continued until adequate data on the zinc corrosion rate is collected; after which an appropriate planned maintenance schedule, not to exceed monthly, will be adopted.

l e f .' .

s. -

"..~ ,-.

1 1---  ; .

' : 2 '. oM . .
  • 9; '. .~i".~.

r '. '. ; ~. . .

2.-

~

. = . ...=.. v..- :5 + -.  :. v ..

.a .

.