ML19329A238
| ML19329A238 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Indian Point, Saint Lucie  |
| Issue date: | 05/03/1978 |
| From: | Shao L Office of Nuclear Reactor Regulation |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001020733 | |
| Download: ML19329A238 (3) | |
Text
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l NOTE TO:
D. Eisenhut, Assistant Director
~
for Systems & Projeds
,4 i
p Division of Operating Reactors
't FROM:
L. C. Shao, Chief.
Engineering Branch Division of Operating Reactors
SUBJECT:
STATUS OF STEAM GENERATOR OPERATION AT OCONEE UNIT 1.
ST. LUCIE UNIT 1. AND INDIAN POINT UNIT 2 DATE:
APRIL 27,1978
.The following is a sumary of the current status of the steam generator at Oconee Unit 1. St. Lucie Unit 1, and Indian Point Unit 2.
OCONEE UNIT l I
A primary to secondary stear generator leak was detected at Oconee Unit 1 on the morning of Thursday
.pril 20,1978 at 4:30 A.M.
The leak in-creased steadily until it leveled off at a. rate'of 0.25 GPM at 9:00 P.M.
It then fluctuated just above 0.25 GPM until Friday April 21 at 10:15 A.M.
s when the leak rate exceeded the unit's 0.3 GPM technical specification 4
leakage rate limit and the unit was shut down. The plant was operating at 100% power up to the time of shut down. Inspection of the steam generator for the leak did not begin until Wednesday, April 26 because I
of excessive airborne reactivity in the containment. No results from the on-going inspecti'on are available at this time. Duke Power Company l
has not postulated the nature of the leak although they believe it is in Steam Generator "B" and because of the sudden indication and relatively l
rapid increase in leak rate they do not believe that it is a leaking tube plug. Duke Power Company is working closely with Babcock and Wilcox in establishing an inspection program and has' indicated that they intend to perform tube inspections possibly including all tubes with previously known degradations. Although the inspection program has not been officially established we advised them that inspection of those tubes would be prudent. We are being continuously informed on the development of this situation and will provide additional information as it becomes j,
F available.
ST. LUCIE UNIT 1 f
m.
St. Lucie Unit 1 (Florida Power and Light Co.)eis currently conducting l'
steam generator inspections during their first refueling outage. The }
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- D. Eisenhut 21, 1976 has unit which began comercial operation on December 1
Combustion Engineering Steam Generators similar in design to Millstone Unit 2 and has operated continually with AVT secondary wat The inspection program to date included-380 hot leg tubes l
Preliminary results chemistry.
and 110 cold leg tubes in one steam generator.The average dent magnitude is in 1
indicated 55 tubes with dent signals.
the range of 0.001" to 0.002" with the maximum dent magnitude o We requested through P. Erickson ORPM, the following being 0.004".
from Florida Power and 1.ight Company:
a ' tube map indicating the locations and elevations of the den (1) the number of dondanser tube failures during the first cycle of tubes.
(11) t.hthe measured chloride levels following condenser tube failures, operation / -
(l11) and to look for signs of support plate cracking.
j (iv)
WE have also requested that a detailed report of the inspection re I
20, 1978.
submitted prior to the plants tentative restart date of May me m,
g-be l
INDIAN POINT UNIT 2_
a we c
Con Edison (licensee) removed a section of the No l
support plate containing the Inconel tubes from steam generato On April 25, 1978 l
The support plate section contained the first two The rows of tubes in columns 3 thru 13 occupying an area ~14" by 5".
at Indian Point 2.
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procedure specified cutting the section including the Inconel tub the EDM process and removal was through a 6 inch diameter hand h i
While
~38 inches below the No.1 support plate near the tube sheet area.
guiding the support plate through the hand hole, the"s.upport. p i
resulting in six of twenty-two tubes falling away from the support p Thirteen tubes remained intact in the and three other tubes were loose. support plate in which the J
l Preliminary visual examination revealed the following:
I Corrosion p'roducts appear to be holding the tubes in the support 1.
plate.
Measurement of the flow slots indicated flow slot clo leg side of.3 inches while
- 1. inches was reasured on the cold side.
2.
Flow holes between rows 1 and 2 were deformed into an eliptical shape where the difference in the major and minor diameters is
. 3.
The major axis is perpendicular to the flow slot.
~1/4 inch.
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D. Eisenhut !
4.
Flow holes between the second and third rows were not as distorted as those between rows one and two.
5.
Flow holes beyond the 3rd row of tubes do not appear distorted i
by bor6 scope observations.
- 6. ' Cracks in the support plate appeared between the flow holes and l
the tube holes (ligaments) with missing tubes. These cracks do l
not appear to have occurred during support plate removal.
The licensee is preparing a report on this matter and has requested tA meet with the staff on May 5,1978. Presently the plant is shut down
~ and start-up is expected between May 8 and May 23, 1978.
t i
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l L. C. Shao, Chief a
l Engineering Branch Division of Operating Reactors cc:
V. Stello, Jr.
J. Reece B. K. Grimes A. Schwencer l
P. Erickson T. Wambach M. Fairtile i
B. D. Liaw i
F. M. Almeter i
D. D11 anni R. G. LaGrange D**
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J. R. Strosnider nj.S R. Mattson J. P. Knight i
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