ML19344D945
| ML19344D945 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 08/07/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| References | |
| NUDOCS 8008260416 | |
| Download: ML19344D945 (1) | |
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'#o UNITED STATES NUCLEAR REGULATORY COMMISSION
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- E REGION I o,
g 631 PARK AVENUE
,d KING OF PRUSSIA. PENNSYLVANIA 19406 August 7, 1980 Docket No. 50-29 Yankee Atomic Electric Company ATTN:
Mr. James A. Kay Senior Engineer - Licensing 25 Research Drive 1
Westborough, Massachusetts 01581 Gentlemen:
The enclosed IE Information Notice No. 80-29," Broken Studs on Terry Turbine Steam Inlet Flahga," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely.
. A % d, Boy e H. Grier Director
Enclosures:
1.
IE Information Notice No. 80-29 2.
List of Recently Issued IE Information Notices CONTACT:
D. L. Caphton (215-337-5266) i CC W/enCls:
H. Autio, Plant Superintendent J. E. Tribble, President 8008260 416
O ENCLOSURE 1 SSINS No.: 6835 UNITED STATES Accession No.:
NUCLEAR REGULATORY COMMISSION 8006190028 0FFICE OF INSPECTION AND ENFORCEFENT WASHINGTON, D.C.
20555 IE Information Notice No. 80-29 Date:
August 7, 1980 Page 1 of 1 BROKEN STUDS ON TERRY TURBINE STEAM INLET FLANGE When removing the governor and stop valve on the Unit 1 steam driven emergency feedwater pump at Arkansas Nuclear One for repair of a steam leak at the steam inlet flange, Arkansas Power and Light discovered that five of the eight studs securing the flange were broken.
The cause of the stud failure is unknown at this time.
Metallurgical evalua-tion of the failed bolting will be performed to identify the mode of failure.
The failed studs are 3/4 in. diameter by 3-1/2 in.
long and are thought to be of ASTM-A-193 grade B7 steel.
The turbine flange bolting is generally covered with insulation and not visible fer inspection.
From the information available, the bolting has not been removed or inspected since installation seven tr.
eight years ago.
The steam driven emergency feedwater pump turbine at ANO-1 is a type G turbine manufactured by the Terry Steam Turbine Company of Hartford, Connecticut.
The turbine is rated at 680 BHP and 3560 RPM.
The turbine operates at a reduced steam pressure of 270 psig and temperature of 400 F and has previously experienced overspeed trips and vibrations which may have been caused by slugs of water from the piping.
Licensees are encouraged to carefully examine insulation in the flange to turbine casing region for evidence of leakage and consider inspection of the turbine steam inlet flange bolting.
Further, during surveillance testing, care should be taken to observe if abnormal vibration or other transients occur which could promote loss of bolting integrity.
This Information Notice is provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
It is expected that recipients will review the information for possible applicability to their facility.
No specific action or response is requested at this time.
If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
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3 IE Information Notice No. 80-29 August 7, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued Supplement to Notification of 7/29/80 All holders of power 80-06 Significant Events at reactor OLs and near Operating Power Reactor tern OL applicants Facilities 80-28 Prompt Reporting Of 6/13/80 All applicants for and Required Information holders of power To NRC reactor construction permits 80-27 Degradation of Reactor 6/11/80 All holders of Coolant Pump Studs pressurized water power reactor OLs or cps 80-26 Evaluation of Contractor 6/10/80 All holders of QA Programs a Part 50 License Sn-25 Transportation of 5/30/80 Material Licensees in Pyrophoric Uranium Priority / Categories II-A, II-D, III-I and IV-DI; Agreement State Licensees in equivalent categories 80-24 Low Level Radioactive 5/30/80 All holders of an Waste Burial Criteria NRC or NRC Agreement State License 80-23 Loss of Suction 5/29/80 All holders of to Emergency Feedwater power reactor Pumps Ols or cps 80-22 Breakdown In Contamina-5/28/80 All holders of tion Cor. trol Programs power reactor OLs and near term OL applicants 80-21 Anchorage anc Support of 5/16/80 All holders of Safety-Related Electrical power reactor i
Equipment OLs or cps 80-20 Loss of Decay Heat 5/8/80 All holders of Removal Capability at power reactor Davis-8 esse Unit 1 While OLs or cps in a Refueling Mode
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