United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #: 9710280289



Conval Inc.



285 FIELD ROAD, P.O. BOX 1049, SOMERS, CT 06071 PHONE 880-749-0761 FAX

860-763-3557



                                             October 24, 1997



United States Nuclear Regulatory Commission

Document Control Desk         Fax: 301-816-5151

Washington, DC 20555



Subject:  10CFR-Part 21,

          Notification of Potential Safety Related Defect



Dear Commissioners:



This letter serves officially to notify the Commission of a potential

safety-related defect in a basic component of five (5) valves supplied by

Conval to three (3) nuclear power plants in the United States.



The three (3) nuclear plants affected are:



     o    Maine Yankee Atomic Power          (3) Valves*_/



     o    Indiana & Michigan Power,

          D.C. Cook 1 & 2                    (2) Valves*_/



     *_/ All three (3) Maine Yankee Atomic Power Valves were unused and

     uninstalled as of October 22, 1997; a UPS Call Tag was issued

     October 24, 1997 for all three (3) valves to be returned to Conval.

     **_/ One (1) of these two (2) valves has been unused and

     uninstalled.



The basic component addressed is the forged valve body of Conval's 1"-

1500# design, #5, Y-Globe, stop valve and check valve, which are

identified as Conval's basic Fig.# 1.00-12G2J-S165F and Fig. # 1.00-12C2-

S165F respectively.  These valves are designed and manufactured by Conval

to meet the requirements of ANSI/ASME B16.34.  The body is forged to the

requirements of ASME SA182-F316.  The forgings were ordered as commercial

grade items and dedicated for safety-related nuclear order use in

accordance with Conval's



                                             Continued next  page.....



NRC 10CFR-Part 21 Notification - 316 Stainless Steel Forgings Page 2 of 3

October 24, 1997



dedication procedure, which is based on EPRI NP-5652 guidelines.



Failure of the body forging in field service could lead to system leakage

or possible body rupture.



The forgings in question were produced by Ideal Forging Corporation,

located at 165 Center Street, Southington, CT.  Ideal produces these

forgings in accordance with the material specification as defined by

Conval's engineering specification.



The information that led to the engineering investigation and reporting

of this potential safety related defect was initiated on Sept. 22, 1997

by Conval's Quality Assurance Manager.



The specific potential safety-related defect relates to a possible crack

within the forging wall at the die flash line.  The forgings affected are

identified as Ideal Forge Heat Code Lot "M7", which is stamped on each

body forging.  During investigation of a valve failure with an "MT" body

on a commercial order, it was determined that the forging process had

generated the potential for an internal body wall defect condition

neither detected by standard visual nor hydrostatic testing methods.

After installation of that valve, operation at a pressure of 2200 psig

and a temperature of 650 degrees F, and subsequent cool-down, a leak was

detected through the body wall.  The valve was removed from the system by

the customer and returned to Conval for review and analysis.



Laboratory analysis revealed that the cracked area of the forging

contained oxides that could only have been generated at the forging

temperature.  The analysis also revealed that the failed body forging

material flow was not optimal in the affected area.  These two conditions

were most likely caused by less than optimal forging temperatures.



Analysis of other Ideal 316 stainless steel Heat Code lots and bodies

forged from other materials causes us to conclude that the reportable

problem is limited to this "M7" heat code lot.



Ideal has taken corrective action steps to eliminate their processing

problem.  They have procured newer temperature monitoring devices at the

forging area heating ovens.  They have also instructed all foremen from

the hammer forge areas on the cause of this defect.  Ideal also conducted

a re-creation experiment duplicating this defect.  This defect was

extremely difficult to re-create, which reinforced their conclusion that

the defect was limited to the "M7" heat Code lot.



NRC 10CFR-Part 21 Notification - 316 Stainless Steel Forgings Page 3 of 3

October 24, 1997



The three (3) nuclear plants affected have been notified of this

potential safety-related defect verbally and in writing as of this date.

These sites have been advised to remove the valves from service and

return them to Conval for replacement of bodies, or replacement of whole

valve assemblies if they desire.  Due to the nature of the defect, Conval

does not advise using any nondestructive testing methods to determine

acceptability of body forgings in the field.



If you have any questions and need additional information concerning this

notification please contact me directly or Mr. David Boyden, Engineering

Manager, immediately.



Sincerely,

CONVAL, INC.



Edward N. Sharpless,

President



GENERAL INFORMATION or OTHER                 EVENT NUMBER: 33144



LICENSEE: CONVAL, INC.                  NOTIFICATION DATE: 10/24/97

    CITY: SOMERS         REGION: 1      NOTIFICATION TIME: 14:09 (ET]

  COUNTY: TOLLAND         STATE: CT     EVENT DATE: 10/24/97

LICENSE#:             AGREEMENT: N      EVENT TIME: 00:00[EDT]

  DOCKET:                               LAST UPDATE DATE: 10/24/97



                                             NOTIFICATIONS



                                        CURTIS COWGILL      RDO



NRC NOTIFIED BY: EDWARD N. SHARPLESS    GEOFFREY WRIGHT     RDO

HQ OPS OFFICER:  STEVE SANDIN           VERN HODGE          NRR



EMERGENCY CLASS: NOT APPLICABLE

10 CFR SECTION:

CCCC 21.21          UNSPECIFIED PARAGRAPH



                               EVENT TEXT



FIVE (5) CONVAL FORGED VALVE BODIES 1"-1500# DESIGN, #5, Y-GLOBE, STOP

AND CHECK VALVE, WHICH ARE IDENTIFIED BY CONVAL'S BASIC FIG. # 1.00-

12G2J-S165F AND FIG. # 1.00-12C2-S165F SUPPLIED TO BOTH MAINE YANKEE

ATOMIC POWER (3 VALVES) AND INDIANA & MICHIGAN POWER (D.C. COOK 1&2)

(2

VALVES) MAY HAVE A DEFECT RELATED TO A POSSIBLE CRACK WITHIN THE

FORGING

WALL AT THE DIE FLASH LINE.  ONLY ONE OF THE FIVE VALVES IS KNOWN TO

BE

INSTALLED AT THE D.C. COOK SITE. THE FORGINGS FOR THESE FIVE VALVES ARE

IDENTIFIED AS IDEAL FORGE HEAT CODE LOT "M7", WHICH IS STAMPED ON EACH

BODY FORGING.  CONVAL DISCOVERED THE FORGING DEFECT DURING AN

INVESTIGATION OF A VALVE RETURNED BY A CUSTOMER.  IDEAL HAS TAKEN

CORRECTIVE ACTION TO ELIMINATE THE PROCESSING PROBLEMS.  THE

AFFECTED

NUCLEAR POWER PLANTS HAVE BEEN NOTIFIED BOTH VERBALLY AND IN

WRITING.



265 Field Road, Somers, CT 06071-1049

Tel. 860-763-3551 ext. 201, FAX 860-763-3557

email: esharpless@conval.com                                 CONVAL, INC.



Fax



To: Untied States Nuclear Regulatory         From: Edward N.  Sharpless

     Commission



Firm:



Fax: 301-816-5151                  Pages: 4 including cover



Phone: 301-961-0550                Date: October 24,1997



Re: 10CFR-Part 21 Notification     CC: D. Boyden, H. Smith



[] Urgent [] For Review Please Comment [] Reply [] Please Recycle



o Comments:



The following three pages are a 10CFR-Part 21, Notification of Potential

Safety Related Defect



*** END OF DOCUMENT ***

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