Part 21 Report - 1997-801
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
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