ML19339A901
| ML19339A901 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 11/22/1972 |
| From: | US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| References | |
| PNO-721122, RO-74, NUDOCS 8011050672 | |
| Download: ML19339A901 (3) | |
Text
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,I No.
74 Date 11/22/72 DIRECTORATE OF REGULATORY OPERATIONS
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- NOTIFICATION OF AN INCIDENT OR OCCURRENCE Facility:
YANKEE ATOMIC ELECTRIC COMPANY (YANKEE)
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Problem:
The Yankee reactor was shutdown on October 20, 1972, for a scheduled four-week maintenance outage. The primary purpose of the outage was
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to replace the cruciform control rods which had exhibited indications P
of binding during recent operations. On November 13, 1972, RO Region 1 y
(Newark) Office was informed by the licensee that, during the control g
rod interchange, foreign objects were observed on the reactor vessel lower core support plate. Examination of the Reactor vessel internals by the licensee, utilizing an underwater TV camera, revealed that two control rod shrouds had been displaced and that the foreign objects were tie down bolts for the shrouds. (The enclosed sectional view of the Yankee reactor vessel shows the location of the control rod shrouds.)
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(=yish An RO inspection was conducted on November 17, 1972, to review the E
licensee's investigative program and findings.
The reactor vessel internals had been removed and a total of eight shroud bolts had been
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recovered from the vessel. The cause of the failure has not as yet been determined. The extent of the delay in resumption of reactor operations is not known at this time; however, RO estimates the reactor
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will be shutdown through January 1973.
No other domestic Westinghouse pressurized water reactors utilize control rod shrouds.
Action:
1.
Yankee is continuing to investigate the matter and will submit a report of this occurrence to the Directorate of Licensing.
2.
RO will follow the progress of the li ensee's investigations and will examine the licensee's findings and corrective action prior to resumption of nuclear operations.
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3.
Commissioner Ramey's Technical Assistant, Commissioner Doub's f' i;d Technical Assistant, the Staf f of the Joint Cocnittee on Atomic Energy and the Office of Information Services are being informed by copy of this notification.
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Contact:
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Further information on this problem can be obtained from:
J. H. Sniezek - X7421 I
J. G. Keppler - X7421 R. H. Engelken-X7356
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Distribution:
Chairman Schlesinger M. Biles, OS D. A. Nussbaumer, L Commissioner Ramey R. F. Fraley, ACRS (3)
R. E. Cunningham, L l
Commissioner Larson L. R. Rogers, RS F. E. Kruesi, R0 Commissioner Doub J. B. Minogue, RS P. A. Morris, RO Commissioner Ray J. J. Davis, RS H. D. Thornburg, RO L. M. Muntzing, DR J. F. O' Leary, L T. R. Wilson, R0 E. J. Bloch, DDR E. G. Case, L R. H. Engelken, R0 C. K. Beck, DRGL J. M. Hendrie, L D. Thompson, R0 S. H. Hanauer, DRTA A. Giambusso, L R. D. O'Neill, OCR D. J. Donoghue, DRA F. Schroeder, L J. R. Totter, DBER W. MacDonald, OPS S. H. Smiley, L J. D. Goldstein, DBER
[7 General Manager (2)
R. S. Boyd, L G. A. Arlotto, RS
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Secretary (2)
D. J. Skovholt, L S. Levine, OEA J. Fouchard, IS R. C. DeYoung, L
- 4. J. Schemel,.L M. Shaw, RDT D. R. Muller, L R0 Regional Offices p;;;.3 J. A. Harris, IS D. F. Knuth, L DR Reading File E
E. J. Bauser, JCAE R. R. Maccary, L REG Central File J. H. Rubin, AGM R. L. Tedesco, L PDR
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J. D. Anderson, INS H. R. Denton, L Local PDR F. Ingram, IS d
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CONTROL ROD LIFTING LUGS
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ORIVE MECHANISM A APTERS REACTOR YESSEL HEAD THERMAL INSULATION RET &lNER GASKET MONITORING TAPS
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CONTROL R00 HEAD ALIGNMENT P;NS HEAD GASKETS
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SEAL WELD MEMBRANE
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W DE BulTONS GUIDE TUBE, i
LOWER CORE SUPPORT BARREL
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ba CONTROL R00 GUIDE TUBE E
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J REACTOR VESSEL SUPPORT LUOS 0L R UPPER CORE SUPPORT PLATE #
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F CORE PLATE GUIDE BLOCKS BATFLE SUPPORTFLANGE sM
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CORE BAFFLE THERMAL SHIELD f-WRR m
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REACTOR VESSEL 7
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LOWER CORE SUPPORT PLATE F
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'Cs FUEL ASSEuBLY TROL R00 HR0 THERMAL SH: ELD SUPPORT LUGS SHROUD TIE PLATE f
c THERMAL INSULATION SUPPORT BRACKETS CONTROL R00 EXTENSION CONTROL ROD SHROUD BOLT LOCATION c:
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REACTOR VESSEL ASSEMBLY
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