ML19256D705
| ML19256D705 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/28/1977 |
| From: | Shao L Office of Nuclear Reactor Regulation |
| To: | Goller K Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7910220623 | |
| Download: ML19256D705 (3) | |
Text
. _
~~
w e
om D
D l
f NOV 2 81977 TowA Ej._
o MEMORAMDUM FOR:
K. R. Goller, Assistant Director for Operating Reactors, Division of Operating Reactors FRON:
L. C. Shao, Chief. Engineering Branch, Division of Operating P.eactors
SUBJECT:
THREE MILE ISLAND UNIT NO.1 - REACTOR CONTAINMENT BUILDING - RING GIRDER SURVEILLANCE TEST THREE YEARS AFTERS.I.T.(TAC 7033)
Plant Name: Three Mile Island Unit No. 1 Licensing Stage: Operating Plant Docket No: 50-289 Documents Reviewed:
- 1. Three Mile Island Nuclear Station Unit 1 -
Reactor Containment Building Ring Girder Surveillance Test Three Years After S.I.T.,
~
June 17,1977 2.
Additional information provided by Licensee in letter to R. W. Reid, dated August 26, 1977 Branch and Project Manager Requesting Assistance: ORB-4, G. Zwetzig, R. Reid Requested Completion Date: 12/1/77 Operating Reactors Branches Involved: Engineering Branch Description of Request: TAC 7033 Review Status: Complete The Engineering Branch, Division of Operating Reactors has reviewed
. the structural and material aspects of the infonnation subnitted by the Metropolitan Edison Company in a submittal dated June 17, 1977 detailing the reactor butiding ring girder surveillance program done three years after the drudural integrity tests. This is in accordance with TMI-1 Technical Specification 4.4.2.2.
Scope of Licensee's Inspection In the document sited above the licensee has addressed the following items:
1 1.
Surveia11ance acceptance criteria 1453 105 2.
Strain gage measurements 3.
Visual inspection of concrete cracks and crack; patterns ir, selected areas a
Tae y t4na n# Aa-- t-L -
1 ;7j7,g p];+2 ; 7. ;; 707 ::.jetjeg,.,ej d; 3.q scaling 4
" OATE >
g.--.
Md.
.e e-Es
-a 1 4
a w
c.
K.'Goller 2
NOV 2 81977 The surveillance test was conducted during the period from May ?, 1977 to May 27, 1977. Strain gage measurements were taken to monitor the stresses in the ring girder reinforcing bars. There has been no appreciable change in these stresses since the previous tests.
Concrete cracks and crack patterns in four whitewashed areas were measured and recorded.
All of the observed cracks widths were found to be within acceptable limits. However, seven concrete voids were previously found adjacent to the reactor building dome tendon bearing plates.
The voids were measured and an evaluation was made to find the impact of these voids on the structural integrity of the reactor building.
It was found that the volds do not decrease the safety factors to which the buidling was originally built. The licensee plans to repair these voids although it is fe'lt that the voids do not impair structural integrity. A timetable for this repair has been provided along with a discussion of r.ne methods and materials to be incorporated.
D**} *D'Tl}
Evaluation
,,h, Ad Theinformationprovidehbythelicenseeinthedocumentcitedabove
,E
' indicates that the surveillance tests have been performed in accord-
_ ance with existing regulations and that the actual safety margins 1r in the structure, at the present time, are adequate. Reasonable assurarce has been provided to confirm that the containment structure 1:.
will continue to perform its, specified safety function.
Conclusions and Recommendat1on_ s The main conclusion by the licensee is that the repaired ring girder is capable of fulfilling its design functions as repuired, deppite minor deteriorations disclosed by the surveillance tests.
We concur with this conclusion. However, we have the following reconnendations:
1.
We insist again that the repairs should be performed as planned and not later than the end of the refueling outage of 1978.
2.
Section 4.4.2.2A of the Technical Specifications for Three Mile Island Unit No.1 (TMI-1) requires four inspections of the containment ring girder at various times after the Structural Integrity Test. It also states that the requirement for further inspection will be determined following review of the report of the fourth inspection.
-14
' since the six month,'one year,53 106 The licensee indicates that years, and three years surve,illance inspections have not uncovered two any significant structural problem, Metropolitan Edison Company, in accordance with Technical Specification 4.4.2.2A does not plan to ennAvt Anethme n=4nn n4=4as. eueaum411mnea +ae+e amen n eveveates h cate> g.
~
- u. F C N " J3: g y a m 9 9,,,,,,
- p.==
--nn. ome s. in.
e (g _
h K. Goller NOV 2 81977 On the basis of our previous evaluations and the new information provided by the licensee in the report cited above, we concur with the licensee's decision. This recormendation is contingent upon the performance of planned repairs in accordance with our recomendation (1) above.
3.
We also recomend that during further service surveillance procedures performed in accordance with the reconmendations of the !!agulatory Guide 1.35 a visual inspection of the ring girder be performed by the licensee and its results reported to the NRC as provided in R.G. 1.35.
.s r -
L. C. Shao, Chief Engineering Branch 3..'
~p Division of Operating Reactors y
o.
~.
.:Contacti '
4-s.O,
~
i.. ~
.. A. Gluckmann
/ - /
u S.;.. +,
s
~
28060 J. 3 r ! v'..
[q, y;
_j-,,.
1,
~
14 cc:
- 7. Stallo" n
~
fr R. Mattson
.. ? '" '
i
-J. Knight
.. D. Ziemann t-
~
" Io m
N R. Reid
~
L. Shao '
- 3. f,, &
]A)uino R. Stuart D**D 1
A. Gluckmann e'
.. f a
l G. Zwetzig H. Lavin R. Cudlin J. Guibert
~
1453 107 r
i e
~
/1 4
orrica w FR DOR #1.
FP Dna FR-nnD s
l ~~
r rJ QQ
(("
summaus h AGlitrakmtnn dr DRtith et 1(Rhnn 11/25/77 11/df77 11/?M77
..a= m me><> x=c= a24a_. m. a.- -
- r -
a _
.