United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 82-30: Loss of Thermal Sleeves in Reactor Coolant System Piping at Certain Westinghouse Pwr Power Plants

                                                            SSINS No.: 6835 
                                                            IN 82-30 

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                          WASHINGTON, D. C. 20555 

                               July 26, 1982 

Information Notice No. 82-30:   LOSS OF THERMAL SLEEVES IN REACTOR 
                                   COOLANT SYSTEM PIPING AT CERTAIN 
                                   WESTINGHOUSE PWR POWER PLANTS 

Addressees: 

All nuclear power reactor facilities holding an operating license (OL) or 
construction permit (CP) and applicants for operating license (NTOL). 

Purpose: 

This information notice is to provide further notification regarding the 
continuance of thermal sleeve failures in both pressurized and boiling water
reactor (PWR and BWR) plants. The potential safety significance of this 
problem is still under review by the Nuclear Regulatory Commission (NRC) 
staff. If NRC evaluation so indicates, further licensee action may be 
requested. In the interim, the staff expects licensees to review the 
information herein for applicability to their facilities. No specific action
or response is required at this time. 

Description of Circumstances: 

Past operating experience has identified fatigue failure problems associated 
with nozzle-thermal sleeve assemblies in piping systems of both BWR and PWR 
plant designs. (1)  Similar fatigue failure problems have occurred more 
recently in certain PWR plants designed by Babcock & Wilcox and are 
described in Information Notice No. 82-09, dated March 31, 1982. 

On June 9, 1982, NRC was notified by Portland General Electric (PGE) that a 
steel sheet about 7" x 15" x 1/8" thick, with torn edges, was discovered in 
the bottom plenum of the Trojan reactor vessel during an underwater 
television inspection of in-reactor fuel conditions. Further inspection 
revealed another metal piece lodged between the lower core plate and core 
support plate. The pieces appeared to be parts of thermal sleeves initially 
installed in the safety injection accumulator piping nozzle connections to 
the reactor coolant system (RCS) cold leg piping. Radiography and ultrasonic
examination further confirmed the 10-inch thermal sleeves were missing from 
all four safety injection (SI) piping nozzle connections. 

The thermal sleeves consist of straight cylindrical sections. Two retainer 
welds about 5/8- to 3/4-inch in length, located 180 apart, attach the 
sleeve to the SI nozzle inlet. Four nozzle button welds and a raised, 
integral machined ring on the thermal sleeve provide axial alignment of the 
sleeve at the nozzle-to-RCS interface. 


(1)NEDO-21821, 1978; NEDO-9693, 1980; WCAP-7477, 1980; NUREG-0691, 1980. 

8204210403 
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                                                           IN 82-30 
                                                           July 26, 1982  
                                                           Page 2 of 2 

Based on the above results, the nozzle-thermal sleeve assemblies of similar 
design were examined with the following results. A crack indication was 
found in one of the two retainer welds of the 14-inch sleeve in the 
pressurizer surge line, to RCS hot leg connection. A slight indication was 
found in a retainer weld on one of the two 3-inch thermal sleeves in the 
normal and alternate charging lines. 

Plans are being developed by PGE for recovery of the thermal sleeve 
components from the vessel and analysis of the failure mechanism. PG and 
Westinghouse are currently evaluating the need for replacement sleeves that 
have failed or those that may be removed because of potential failure. 

Duke Power Company also notified NRC that a radiography examination and 
underwater camera inspection on July 4 and 5, 1982, respectively, indicated 
the thermal sleeve in one of the four SI accumulator piping nozzles to RCS 
cool leg piping (i.e., Loop B) in McGuire Unit 1 was missing. Radiography 
confirmed the sleeves in Loops A, C, and D, as well as the pressurizer surge
line to RCS hot leg piping, to be in place. However, conditions of all th.e 
retainer welds in the affected systems remain to be established. 

Westinghouse has notified its PWR customers of affected operating and 
nonoperating plants with regard to the thermal sleeve problem. For the 
operating plants, Westinghouse has recommended that (1) the loose parts 
monitoring system be fully operational and (2) a nondestructive examination 
be performed to assess thermal sleeve conditions of affected systems at the 
next extended plant outage. Implementation of these measures would appear 
prudent until this matter can be fully resolved. 

If you have any questions regarding this matter, please contact the Regional
Administrator of the appropriate NRC Regional Office, or this office. 



                              Edward L. Jordan, Director 
                              Division of Engineering and 
                                Quality Assurance 
                              Office of Inspection and Enforcement 

Technical Contact:  W. J. Collins 
                    301-492-7275 

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