ML19332B223
| ML19332B223 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 08/07/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8009260298 | |
| Download: ML19332B223 (1) | |
Text
I j, f* *% y t
!j o.
UNITED STATES 3
NUCLEAR REGULATORY COMMISSION
,E REGION V o,
g 1990 N. CALIFORNIA BOULEVARD
%*e,,* e SUITE 202, WALNUT CREEK PLAZA WALNUT CREEK CALIFORNIA 94596 August 7, 1980 Docket No. 50-312 Sacramento Municipal Utility District P. O. Box 15830 Sacramento, California 95813 Attention: Mr. John J. Mattimoe Assistant General Manager Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the infonnation for possible applicability to their facilities.
No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, m NA c
R. H. Engelken Director Enclosures :
1.
IE Information flotice i
No. 80-29 2.
List of Recently Issued IE Information Notices cc w/ enclosures:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD t
l 8 000260D
/
~'
SSIflS No.: 6835 Accession No.:
UNITED STATES 8006190028 NUCLEAR REGULATORY COMMISSI0ft 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 August 7, 1980 IE Information Notice No. 80-29 BROKEfl STUDS ON TERRY TURBINE STEAM INLET FLANGE When renoving 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-193 grade B7 steel. The turbine flange bolting is generally covered with insulation and not visible for inspection.
From the information available, the bolting has not been removed or inspected since installation seven to eight years ago.
The steam driven emergency feedwater pump turbine at AN0-1 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 turbirr operates at a reduced steam pressure of 270 psig and temperature of 400F 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.
i 4
9
g..
IE Information flotice No. 80-29 Enclosure August 7, 1980 RECENTLY ISSVED IE IfiFORMATI0ft NOTICES Information Subject Date Issued To flotice No.
Issued Supplement to Notification of 7/29/80 All holder of Reactor 80-06 Significant Events at OLs and to near Operating Power Reactor operating license Facilities applicants 80-28 Prompt Reporting Of 6/13/80 All applicants for and Required Information
~
holders of nuclear power To NRC reactor construction 80-27 Degradation of Reactor 6/11/80 All Pressurized Water Coolant Pump Studs Reactor Facilities holding power reactor Ols or cps 80-26 Evaluation of Contractor 6/10/80 All Part 50 Licensees QA Programs 80-25 Transportation of 5/30/80 Material Licensee 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 NRC and Agreement Waste Burial Criteria State Licensees 80-23 Loss of Suction to 5/29/80 All power reactor to Emergency Feedwater f3cilities with an Pumps OL or CP 80-22 Breakdown In Contamina-5/28/80 All power reactor tion Control Programs OLs and near term cps 80-21 Anchorage and Support of 5/16/80 All power reactor Safety-Related Electrical facilities with an Equipment OL or CP EO-20 Loss of Decay Heat 5/8/80 All light water reactor x
Removal Capability at facilities holding Davis-Besse Unit 1 While power reactor OLs or cps in a Refueling Mode l