ML19340E063
| ML19340E063 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 11/26/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Millen C PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 8101060293 | |
| Download: ML19340E063 (1) | |
Text
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UNITED STATES PDR:HQ e
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NUCLEAR REGULATORY COMMISSION
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8 611 RYAN PLAZA DRIVE, SUITE 1000 h,, [, ~#
ARLINGTON. TEXAS 76011 STATE November 25, 1980 Cocket No. 50-267 Public Service Comoany of Colorado ATTN:
Mr. C. K. Millen Senior Vice President P. O. Box 840 Denver, Colorado 80201 Gentlemen:
This IE Information Notice is provided as an early notification of a possible significant matter.
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 further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recomend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely,
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v Karl V. Seyfri' Director l
Enclosures:
1.
IE Information Notice l
No. 80-29 Supplement No.1 2.
List of Recently Issued IE Information Notices cc:
D. W. Warembourg, Nuclear Production Manager Fort St. Vrain Nuclear Station l
P. O. Box 368 Platteville, Colorado 80651 L. Brey, Manager, Quality Assurance 810106000
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SSINS No.:
6835 l
Accession No.:
4 8006190028 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 IE Information Notice No. 80-29 Supplemental No. 1 Date:
November 26, 1980 Page 1 of 1 BROKEN STUDS ON TERRY TURBINE STEAM INLET FLANGE Description of Circumstances:
In the original Information Notice the failed Terry Turbine steam inlet flange studs were identified as probably manufactured from ASTM-A193-Grade 87 steel.
Subsequently, the vendor has informed the NRC that the bolting material used at ANO-1 was AISI C-1117 steel.
Independent laboratory analyses by the NRC and Arkansas Power and Light have verified that the bolting material was a re-sulphurized, re phosphorized cold drawn carbon steel.
From the analysis performed, the failure was caused by high overload which resulted in a primarily brittle transgranular fracture (cleavage) in probably less than 10 cycles.
This is consistent with the operating experience (water slugging) and the inherent low toughness of the bolting material used.
Licensees are encouraged to review the materials selected for safety-related bolting applications considering especially those situations where impact loadings could occur.
The use of low toughness carbon steel (re-sulphurized free machining plain carbon steel) for bolting is discouraged by the NRC; particularly in situations where possible high loading conditions could be anticipated.
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 j
appropriate NRC Regional Office.
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IE Information Notice No. 80-29~
Supplemental No. 1 November 26, 1980 LISTING 0F RECENTLY ISSUED j
IE INFORMATION NOTICES l
Information Subject Date Issued To Notice No.
Issued 80-37 Containment Cooler Leaks 10/24/80 All nuclear power and Reactor Cavity facilities holding Flooding at Indian Point power reactor Operating Lait 2 Licenses (OLs) or Construction Permits (cps) 80-38 Cracking in Charging 10/30/80 All Pressurized Water Pump Casing Cladding Reactor Facilities holding power reactor Operating Licenses (OLs) and Construction Permits (cps) 80-39 Malfunctions Of Solenoid 10/31/80 All light water reactor j
Valves Manufactured By facilities holding Valcor Engineering Corporation power reactor Operating Licenses (0Ls) or Construc-tion Permits (cps) i 80-40 Excessive Nitrogen 11/7/80 All power facilities Supply Pressure with an Operating License Actuates Safety-Relief (OL) or Construction Valve Operation to Permit (CP)
Cause Reactor Depressuriza-tion 80-41 Failure of Swing Check 11/10/80 All power reactor Valve in the Decay Heat facilities with an Operating Removal System at David-License (0L) or Construction Besse Ur,it No. 1 Permit (CP) 80-42 Effect of Radiation 11/24/80 All power reactor j
on Hydraulic Snubber Fluid facilities with an Operating License (0L) or Construction Permit (CP) l Enclosure l
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