ML20031F162
| ML20031F162 | |
| Person / Time | |
|---|---|
| Issue date: | 09/30/1977 |
| From: | Zudans J Office of Nuclear Reactor Regulation |
| To: | Shao L Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13319A640 | List:
|
| References | |
| FOIA-81-313 NUDOCS 8110190287 | |
| Download: ML20031F162 (4) | |
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g UNITED STATES
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NUCLEAR REGULATORY COMMisslON Y
WASHING TON, D. C. 20555 k, * * "
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,.... 7 MEMORANDUM FOR:
L. C. Shao, Chief Engineering Branch, D0R FROM:
J. Zudans, Engineering Branch, DOR THRU:
R. Stuart, Section B Leader Engineering Branch, 00R l
SUBJECT:
TRIP REPORT - LYNCHBURG B&W MEETING: SAFETY RELATED RESEARCH AND DEVELOPMENT On Thursday, September 6,1977 B&W held their annual meeting with NRC to describe present and future R&D efforts being conducted at the Lynchburg Research Center. Highlight of the areas of special interest and a complete agenda are enclosed.
j C0 Jj' Zudahs
'ingineering Branch Division of Operating Reactors
Enclosures:
As stated cc:
V. Stello R. Mattson D. Eisenhut J. Knight R. Cudlin J. Guibert R. Stuart EB Members ff,**Cee7 PDR e,
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LYNCHBURG B&W MEETING: SAFETY RELATED RESEARCH AND DEVELOPMENT DATE OF MEETING:
SEPTEMBER 8, 1977
. MEETING ATTENDED AND REPORTED BY:
J. J. Zudans The following !tems of interest were presented:
1.
OTSG Tube Examination and Field Instrumentation Program A brief history indicates that out of 14 B&W steam generators in service 4 have developed leaks and all 11 leaking tubes in these steam generators are located at Duke Power Co., Oconee units 1, 2 and 3.
Most of the leaks have occurred in the super heat region of the S.G. in the open lane sector, from support plates 13 through 15.
In a effort to curtail these tube failures B&W has initiated an inspection capability, and a tube sample removal capability.
In addition a tube stabilizer
" nail" has been developed and field instrumentation has even installed in Oconee 2 steam generator B.
The inspection methods involve eddy current tests, visual examinations utilizing fiber optics,and video, chemical, and X-ray diffraction examinations.
Eddy current tests have provided identification of leak defects, distorted tubesheets and damaged support plates. Visual examinations have provided data on the ci.anliness of the tubes, deposit variations at different elevations of the S.G., and tub 'afects. Five tubes have been removed from the steam generators at Oconee and have yielded material data using lab examinations and X-ray diffraction procedures.
t Typical examination results atsupport plate 15 Tube 77-25 unit 1-B showed:
1.
Crack within the confines of the support plate 2.
Single 0.D. crack Origin 0
3.
One level propagation with a 90 span
- 4. Origin related to 0.D. surface depression 5.
Probable cause - High cycle - Low stress fatigue 6.
No intergranular stress-corrosion cracking
,e 7.
No evidence of metal loss i
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The lab exam on tube 77-25 showed:
1.
Abnormal Eddy Current Signal.
2.
Depression circumscribes 250 of tube with an 1 mil depth 3.
Axial wear in the depression Generally corrective measures taken have entailed:
1.
Plugging tube affected.
7 2.
Installing tube stabilizer " nail" 3.
Removal of tube Fixes presently proposed by B&W entail:
1.
Plugging aux. noz2.lcs in the super heat region which inject chilled water into the steam generators 2.
Stabilize open lane tube 8-30 3.
Restrict turbine stop valve testing (no recomendations for intervals were made) 4.
Implement Corrective measures.
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In addition to the above stated work B&W has instrumented the Oconee II-B S.G. in order to provide greater knowledge of actual OTSG operating parameters relative to structural and thermal response. Their objectives are to:
1.
Obtain vibration data in the oper lane.
2.
Instrument two stabilizers 3.
Obtain pressure drop & flow data in the steam line.
In order to accomplish this objective the following instrumentation has been installed:
1.
Internal bi-axial accelerometers in a tube between 114 support plate and the tube sheet.
2.
External accelerometers 3,
Fluctuating pressure probe between the S.G. shroud and S.G. wall at the auxiliary nozzle 4.
Bulk s' team flow measurement device j
Data has been compiled and results of these measurements will be available soon.
SEPTEMBER 8,1977 SAFETY-RELATED R&D' MEETI'NG
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f B8W/NRC
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SPEAKER l
AGENDA
, 8:00, INTRODUCTIONS s
8:15 PIE PROGRAM.
M.H.110NTG0ERY 9:30 DEMONSTRATION ASSEMBLIES l
10iOO EP'RI PWR PROGRN1 T.F. PAPAZ0GLOU 11:00 R0D B0}l (ECilANICAL. ASPECTS)
[
R.A. KING 11:30 MK-C DEVELOPENT j
)
i 12-1 LUNCH l
t l
'1:00 OTSG TUBE EXAMINATION AND D.F. LEVSTEK FIELD INSTRUENTATION PROGRAM L.H. B0HN R.H. ST0UDT
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2:00 CHF PROGR M 3:00 STATISTICAL CORE DESIGN B.E. BINGHAM 3i30
- RABIATION CONTROL D.L. UHL
- ll:00 ADJ00RNIENT/LRC TO'UR AS TlHE PERMITS
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