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| Entered date | Event description | |
|---|---|---|
| ENS 53177 | 18 January 2018 16:06:00 | The following is a summary of the information received from Velan Inc. via facsimile: Affected item: Velan Inc. Disc (part number 8205-012) in 4NPS Class 150 through 900 Swing Check Valve Callaway Nuclear Plant discovered that a Velan check valve installed in 1999 was stuck open. Velan investigated and determined that in 1979, a design change increased the thickness of the disc to allow the check valve to be used in higher pressure applications than the original design. In 1985, the valve body cavity was enlarged which would preclude the disc from sticking. Therefore, the only affected valves are the valves manufactured between 1979 and 1985. Velan's records only go back to 1982 for purchase orders of this valve. Their records indicate 157 discs of this part number were shipped to U.S. utilities. The following actions are being taken with respect to the disc: - Cancel disc part number 8502-012 - Create a new disc part number to fit the body geometry of 1985 and before -Create another disc part number to fit the current body geometry. All affected utilities will be notified within a week, for information and to determine a course of action. As a minimum, Velan will recall all discs of the aforementioned part number in inventory at these utilities. For any additional information on this matter please contact Victor Apostolescu at 514-748-7748 x 2134 or at victor.apostolescu@velan.com. This disc has been purchased by nuclear plants in all four USNRC regions.
Revised Part 21 report with corrected part number on page 1. Part number for disc revised to 8205-012. Notified R1DO (Gray), R2DO (Guthrie), R3DO (Cameron), R4DO (Pick), and Part 21 Group via email. |
| ENS 50284 | 18 July 2014 08:28:00 | The following information was received from Velan Inc by facsimile: SUBJECT NOTIFICATION: 2 INCH BONNETS, VELAN PART NUMBER 8943-014 On May 16, 2014 (Velan) received notification from Westinghouse Electric Co. (WES) that 2 bonnets supplied by Velan to WES in early 2013 for installation at Comanche Peak exhibited the following issues: - The bonnets were intended to be exact replacements for the bonnets built to drawing E73-020 Rev E (OEM is Velan) except for material change to SA-182 FXM-19. Bonnets were visually inspected when received at site. No issues were noted; both bonnets appeared to be identical. - In April 2013, Unit 1 bonnet was installed in valve 1-8109. No issues were noted with the installation. The new bonnet was put into service. -In April 2014, Unit 2 installation was scheduled to begin. After the disassembly of the valve, the old and new bonnets were compared. It was noted that the backseat dimensions are different between the 2 bonnets. The increase in backseat diameter on the new bonnet would cause the stem to not backseat. The decision was made to re-install the old bonnet and send the new bonnet back to the OEM, Velan. On June 10, 2014 the bonnet, identified in the last bullet above, arrived at Velan Plant 2. The review by the (Velan) Evaluation Committee was finalized on July 17 and concluded that: -Four similar bonnets were delivered to WES on three different occasions in 1988 and early 90's -The stem head diameter is 01.312 (inches) so, when opening, the stem may pass through the stem bore of the bonnet and not seat on the backseat. -On opening, if the limit switches on the actuator do not function, the stem may enter the packing chamber. The packing may be deformed and a leak may develop. Stem travel is limited by the disc contacting the bonnet and/or the end of the stem thread stopping on the actuator drive nut. -If the actuator and packing flange nuts are removed, there is the potential for the stem to blow out of the valve. -The packing chamber depth will result in more packing being installed in the valve. This may result in a higher packing friction load on the actuator when operating and reduce the actuator margin. -The smaller packing chamber will not affect safety. A different diameter packing may be required. The gland bushing diameter (01.744 inches) is less than the packing chamber diameter and will work correctly. These bonnets were fabricated against ASME Sec. Ill for installation in Class 2 systems. Not knowing exactly the nature of the application we cannot determine if the (above identified) potential issues may pose a significant safety hazard and therefore we have informed WES by way of a similar letter.
Reporting Organization/Supplier who made the original event report on 07/18/2014 reported to the NRC Operations Center that the Event Notification posted has a typographical error regarding the Velan, Inc part number described in the report. The original documentation provided was concerning Velan Part Number 8943-014 which was mistakenly transcribed as 6943-014 in the original report. This error has been corrected in this updated report. Notified R4DO (Okeefe) and Part 21 Group via email. |
| ENS 46923 | 3 June 2011 16:30:00 | The following is a summary of a Part 21 e-mail notification received from Velan Inc: Velan Inc., a valve vendor, has identified a potential defect in certain lots of 0.5, 0.75 and 1 inch NPS globe valves sold to Areva and Fenoc. The failure could result in the valve travelling into the bonnet cavity and became jammed between body and bonnet. The analysis revealed that the failure was caused by the wrong bonnet being installed on the valve which ultimately allowed the disc to travel too far into the bonnet cavity and consequently the disc dropped into the body-bonnet gap. This prevented the valve from being closed during manual operation. Internal analysis also determined that this failure mode is very plausible in valves installed with the stem in a horizontal orientation. Valves installed with the stem in vertical orientation are far less likely to fail but we cannot guarantee that; on valves that are normally fully open certain flow conditions may cause the disc to tilt and jam between body and bonnet. Nevertheless, operational history seems to suggest that valves installed with the stem in vertical orientation have not experienced this type of failure. Velan has requested that each affected utility reviews the individual applications for the specific valves identified in this notification; in the event of any application where the valves inability to close will impact significantly the safe operation of the plant. Velan will work with the utility towards reaching a suitable solution. Velan does not have specific information concerning the specific system and function applicable to these globe valves and therefore we cannot assess whether a substantial safety hazard exists as a result of their inability to close after falling as described above. Velan's investigation and review of the available manufacturing records revealed that the same bonnet, with an oversized lift, was installed in all valves identified hereunder. CUSTOMER ORDER QTY. VALVE FIGURE No. VALVE SERIAL No. AREVA NP 8 W04-2074B-02AA 971022-1 to-8 AREVA NP 12 W03-2074B-02AA 971042-1 to -12 AREVA NP 27 W04-2074B-02AA 971048-1 to -27 AREVA NP 5 W03-2074B-02AA 981028-1 to-5 AREVA NP 5 W03-20748-02AA 981030-1 to-5 AREVA NP 10 W05-20748-02AA 001012-1 to-10 AREVA NP 13 W03-20748-02AA 001029 -1 to -13 AREVA NP 26 W04 20748-02AA 001056 -1 to -26 ARE VA NP 10 W04-20748-02AA 011035-1 to-10 FENOC 4 W05-2074B 02AA 001033 -1 to-4 |
| ENS 46403 | 8 November 2010 16:02:00 | The following report was received via fax: During the performance testing of our valves equipped with Limitorque SMB-00 we found that the limit switch contacts proved to be defective. These tests took place in July 2010. Flowserve was advised and sent in replacement parts that were installed by their representatives. The valve-actuator assemblies were cycled and proper operation was assessed. These valves have been shipped to Dominion Virginia. At the time we considered the issue isolated and did not pursue an in-depth corrective action response from the Supplier. Later in September when testing three valves equipped with Limitorque SMB-00 and two valves equipped with Limitorque SMB-2-06, we found again that the limit switch contacts were defective, exhibiting similar problems as found earlier in July. These valves are still at our factory, awaiting the response and corrective action from Flowserve. The limit switch boxes (4 gear train limit switches, 16 sets of contacts) appear to be identical on the two types of actuators mentioned above. Upon closer examination, we determined that construction and installation elements appear poorly controlled, resulting in unexpected failure to operate due to the contact blade (called finger base by the Manufacturer) not returning to a position where it can make contact again. This was documented internally on a Velan internal deviation report on September 3, 2010. We advised Flowserve of our findings on September 15 and issued a formal Corrective Action Request (CAR 25500-73903) on September 16, 2010, with a deadline for responding that expired on October 26, 2010. After a number of follow-ups, we managed to make contact with responsible personnel at Flowserve on October 29. An evaluation report (electrical continuity test performed on sample switch assemblies cycled 2000 times) was submitted to our attention by Flowserve. However, we determined that the test did not answer all our concerns and requested Flowserve to provide additional information. Currently the supplier is engaged in retrieving the defective parts from our facilities and performing additional examinations and tests. The Manufacturer expects to have all necessary tests, examinations and evaluations completed on or before November 19, 2010. Based on functional testing performed at Velan we determined that we have no record of similar defects on valve-actuator assemblies produced prior to these events, we therefore believe that the root cause is relatively recent but there is no way to know until Flowserve analyzes and evaluates the deficiency. This type of defect has the potential to affect other valve manufacturers who may have installed Limitorque actuators equipped with this type of limit switch but we cannot say if such deviation could create a substantial safety hazard.
On January 14, 2011, Velan received the final report from Flowserve concerning limit switches identified in this notification. Velan has accepted the conclusions in the report. The following is a synopsis of those conclusions: It was determined that producing a bend in the contact finger cannot occur during normal cyclic operation of the rotor. It is highly likely that the cause of the bent finger assemblies was due to the use of a flat blade screwdriver. A flat blade screwdriver can also exert enough force to damage the cotter pin hole in the spring stud. Based on testing and evaluations of all returned Velan switches and switches from Flowserve stock, a design deficiency has not been identified. Properly set switches will perform their intended functions. A maintenance update will be issued by Flowserve to guide the industry on any recommendations during their regularly scheduled maintenance outages. Notified R1DO (Newport), R2DO (Sykes), R3DO (Bloomer), and R4DO (O'Keefe). Notified Part 21 Group via E-mail. Notified NRR and NRO via facsimile.
Velan Inc. has issued the final report on this problem with no changes from the January 14, 2011 update. Notified R1DO (Bellamy), R2DO (McCoy), R3DO (Duncan), and R4DO (Clark). Notified Part 21 Group via E-mail. |