ML19290A473

Deficiency Rept Re Grease Leakage Discovered on 730720 from 2090P Casing Filler Mfg by Viscosity Oil Co Into Vertical Tendon Conduits.Liner Plate Checked & No Bulging or Buckling Found.Samples of Leaking Matl Taken

ML19290A473
Person / Time
Site:	Palisades, Arkansas Nuclear, Three Mile Island
Issue date:	08/17/1973
From:	John Miller METROPOLITAN EDISON CO.
To:
Shared Package
ML19290A468	List: ML19290A473
References
NUDOCS 7911070647
Download: ML19290A473 (3)

Text

. .

^'U &"rjgL7  !

, ,a g.. -- -- /

n .n an ex nocom

/

/

/

METROPOLITAN EDISON COMPANY .scunoc anesavusucunune:ccarosanc:. l ,

POST OFFICE BOX 542 READING, PENNSYLVANIA 19603 TELEPHONE 215 - 929-3601 August 17, 1973 P

Dr. D. F. Knuth, Director Directorate of Regulatory Operations United States Atomic Energy Commission Washington, D. C. 20545

SUBJECT:

Three > Ele Island Nuclear Station Unit No. 1 Docket No. 50-289 Grease Leakage from the Vertical Bulk Filled Reactor Building Tendons

Dear Dr. Knuth:

You were notified on July 20, 1973, of a situation which could be considered reportable under 10 CFR 50.55 (e)(1)(iii), " Conditions of Construction Permits." This situation relates to grease leakage from the vertical bulk filled reactor building tendons.

DESCRIPTION OF INCIDENT On July 20, 1973, an investigation was conducted of the reactor con-tainment building exterior concrete wall between the elevations of 279'0" and 284'6". This investigation was conducted as a result of a report of unusual staining of the concrete in that area.

It was found that there was an cil-like substance emerging from approxi-mately 30 vertical hairline shrinkage cracks just above the base mat. The area around the cracka were stained and in some cases there was small accu-mulation on the floor below the cracks. Approximately 12 other leaks were observed higher up on the exposed wall. It appeared that these leaks were also from vertical hairline shrinkage cracks. The actual length of the cracks appeared to be about one foot.

The source of this oil-like substance was concluded to be the 2090P casing filler, manufactured by Viscosity 011 Company, that had been bulk-filled into the vertical tendon conduits. Only the vertical tendon had been stressed and conduits bulkfilled at this time.

The vertical tendons had been bulkfilled during the period June 7 to June 15, 1973. No leakage was observed during this period of bulkfilling or during the period immediately following that tine. It is unknown how long the leaks had been evident before they were discovered.

1557 344

1. 81107o Gp7

Dr. D. F. Knuth ~'

Page Two a

CORRECTIVE ACTION The following are results of actions taken as of August 17, 1973:

1. The liner plate was checked and no bulging or buckling was found.

2. Samples of the bulk fill material were taken from two of the vertical tendons, tested in accordance with ASTM test requirements, and found .

to comply with ASTM and Engineer's specification. A sample of the substance eminating from the cracks will be analyzed and compared with a similar analysis of 2090P casing filler material to determine any separation.

3. It was reported that two plants have experienced similar problems--

Palasades & Arkansas. Viscosity 011 Company has supplied casing filler to both of these projects. At Palasades the material was Visconorust 2090P. At Arkansas two casing fillers were used, Visconorust 2090P and 2090P-1. The Visconorust 2090P-1 is a modification of the original 2090P which increases the consistency slightly at lower temperatures.

According to Viscosity 011 Company, the bulkfill =aterial is wax base and is self-sealing where microcracks are the leakage path as the case here.

4. A total of*59 " Crack / stains" have been discovered as of August 10, 1973, sixteen (16) having appeared af ter the initial survey on July 20, 1973.

A daily survey has been initiated so as to observe the degree of acti-vity of the seeping oily substance. The concrete surfaces at each loca-tion have been cleaned (with solvent) periodically so as to facilitate the evaluation of the degree of flow of the substance.

Of the 59 " crack / stains," apprcximately 37 have maintained a steady flow rate, 11 have reduced flow rates and 11 have become inactive.

Cessation of 20 percent of the presently located leaks indicates a possible self-sealing effect is in progress, which should be aided by stressing of all hoop tendons. Surveillance during doce and hoop tendon bulk filling will be conducted regularly over the entire exterior building surface.

Plans presently call for using Visconorust 2090P-2, the third generation casing filler, which is heavier in consistency than all previously supplied material. This casing filler will be used for the balance of tendon greasing.

Very truly yoursg' ^

v y, / %

J[ G. Miller bav Vice President ec: Mr. J. P. O'Reilly, Director Region I f Directorate of Regulatory Ope, rations Mr. W. A. Verrochi 1557 345 Vice President GPU Service Corporation