ML19256B557
| ML19256B557 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 07/26/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Stewart W FLORIDA POWER CORP. |
| References | |
| NUDOCS 7908070749 | |
| Download: ML19256B557 (2) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION If
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5 REGION 11 C, p.dh, j
101 M A ale T T A ST, N W $Ulf E 3100 AT L ANT A, GE ORGI A 30303
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JUL 2 61979 In Reply Refer To:
Rll:JPO 50-302 Florida Power Corporation ATTS:
W.
P. Stewart, Manager Nuclear Operations P. O. Box 14042, Mail Stop C-4 St. Petersburg, FL 33733 Gentlemen:
The enclosed Bulletin 79-17 is forwarded to you for action.
A written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
"{
st.
James P. O'Rei y (w.
Director
Enclosure:
IE hulletin 79-17 l
l 9 0 8 0 7 0,< u, o
n.,
8 9-Florida Power Corporation.
cc w/ encl:
G. P. Beatty, Jr.
Nuclear Plant Superintendent Post Office Box 1228 Crystal River, Florida 32629
UNITED STATES hTCLEAR Pl.GULAT0hY COM".15S10N OFFICE OF INSPECT 105 AE ES70ECEEN1 b ASHI N GT ON,
D. C.
20S53 Juh 26. 1979 IE bulletin h_
PIPE CRACh515 ST AGNANT BORATE!' MTEF SYSTE",5 AT Pb1 FLANTS Desc r 2ption c f Circumstances.
de 2s During the period of havember 197-to February 1977 a number of cr an:
safety-related stainless steel p2p2ng systems or essent2 ally stagnant have been experiencedwhich contain oxygenated, stagnant in port 2 cns of systems revealed these cracks occ rre:.-
Metallurgical invest 2 Fat nns l (sched
.e It affected zone cf E-inch to 10-2nch type 304 materiaand propag: ting 2 berated water.
an the seld heatitiat ing on the p2; 2ng 1.D.
surface transgranular mode typ2 cal of Stress Corrosicr. Crac'..c r
and 4C), 2 corrodents to be chloride and oxygen contar2-intergranular or 2nd2cated the probable Plants affected up te this time were Arkansas Analysis
- 3. Sar H.B. Robinson Un2t 2, Crystal R2ver Unit nat2cn 2n the af f ec ted systems.
76-06 icopy The h'RC 1ssued Circular Nuclear Unit 1, R. E. G2nna, 1 and 2.
Onofre Unit 1, and Surry Units blem.
attached) in view of the apparent generic nature of the pro I which began 2n Februar; refueling outage of Three Mile Island Unittnrough-wall cracks at se:ds of this year, visual 2nspections disclosed f2ve (5) a weld in the deca 3 heat During the (1) at fuel cooling system p2 ping and onefound as a result of local boric acid 2n the spent These cracks were This initial identif2 cat 2cn remcval systetr.
tests.
confirmed by liquid penetrant Repert (LER) dated "ay repcrted to the hTC in a Licensee Event up and later n
A preliminary metallurg2 cal analysis was performed by the of cracking was from the spent fuel cooling system.
16, 1979.
a section of cracked and leaking weld joint conclusion of this analys2s was that cracking was due to Int 1.D.
The cracking or2ginating on the pipe The was local 22ed to the heat affected zone where the type 301 st St ress Cor rc ss or, Cracking (IGSCC )
In addition te the ma2n during welding.
several locations 2n the sensitized (precipitated carbides) cracks were observed atfusion area through-wall crack, inciplent including the weld rootThe stresses responsible for cr weld beat affected zone d applied lack of fusion had occurred. residual welding stresses in as much as the calcul to be primarily stresses were found to be less than code design limits.gressive chee2 cal spe
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- svs t er evidence at this time to ident 2 f y those this 1GSCC attack. Further analy welds are being pursued.
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