United States Nuclear Regulatory Commission - Protecting People and the Environment

Bulletin 75-01: Through-Wall Cracks in Core Spray Piping at Dresden-2

BL75001 

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                          WASHINGTON, D. C. 20555 

J. P. O'Reilly, Director, Region I 
N. C. Moseley, Director, Region II 
J. G. Keppler, Director, Region III
E. M. Howard, Director, Region IV
R. H. Engelken, Director, Region V 

IE BULLETIN NO. 75-01 -  THROUGH-WALL CRACKS IN CORE, SPRAY PIPING AT 
                         DRESDEN-2 

The subject Bulletin should be dispatched for action to all BWR facilities 
with operating licensees by close of business today. 

The Bulletin should also be dispatched for information to all BWR facilities
with construction permit and to all PWR facilities with operating license no
later than close of business on January 31, 1975. 

The text of the Bulletin and draft letters to licensees are enclosed for 
this purpose. 


                              John G. Davis, Deputy Director 
                                   for Field Operations 
                              Office of Inspection and Enforcement 

Enclosures: 
As stated 
.

(Draft letter to all BWR facilities with operating license) 

                                                     IE Bulletin No. 75-01 

Gentlemen: 

Enclosed is IE Bulletin No. 75-01 which requires action by you with regard 
to your boiling water reactor facility(ies) with operating license. 

Should you have questions regarding this Bulletin or the actions required of
you, please contact this office. 

                                        Sincerely, 


                                        Director 

Enclosure:
IE Bulletin No 75-01 

               Approved by GAO, B-180225 (R0072), clearance expires 7-31-77.
               Approval was given under a blanket clearance specifically for
               identified generic problems. 
.

(Draft letter for information to all BWR facilities with construction permit
and to all PWR facilities with operating license.)   

                                                         IE Bulletin 75-01 

Gentlemen: 

Enclosed is IE Bulletin 75-01-which is forwarded to you for information.  No
action is required of you if you do not have,boiling water reactor with 
operating license. 

Should you have questions regarding this Bulletin, please contact this 
office. 

                                        Sincerely,   


                                        Director 

Enclosure:
IE. Bulletin 75-01  
.

IE Bulletin No. 75-01                                       Date: 1/30/75 

THROUGH-WALL CRACKS IN CORE SPRAY PIPING AT DRESDEN-2 

DESCRIPTION OF CIRCUMSTANCES: 

The Commonwealth Edison company notified the Region III Office of the Office
of Inspection and Enforcement by telephone on January 28, 1975, of the 
finding of five through-wall cracks in the 10" diameter core spray piping 
system at the Dresden 2 facility. 

The licensee reported that 3 cracks were identified in the "A" core spray 
loop and 2 cracks were identified in the "B" core spray loop. The cracks 
were revealed when moisture was observed seeping from them after the pipe 
insulation gas removed in preparation for in-service inspection. The cracks 
range from 1/8" to 3/4" in length on the outside surface. 

The three cracks in the "A" loop are in an approximately 9" long "dutchman" 
insert which is welded on one end to the reactor vessel nozzle safe-end and 
on the other end to the core spray inlet piping. The safe-end and dutchman 
insert are reportedly fabricated from Type 316 stainless steel while the 
core spray piping is Type 304 stainless steel. Two of these cracks are 
longitudinal and in the heat affected zones of the weld between the safe-end 
and dutchman insert. The other cracks are longitudinal and in the heat 
affected zone of the weld between the safe-end and dutchman insert. The 
other crack is circumferential and in the heat affected zone of the weld 
between the inlet piping and dutchman insert. 

The two cracks in the "B" loop are circumferential and on the pipe side of 
the heat affected zone of the weld between the inlet piping and the dutchman
insert. 

Volumetric examination of all welds in the core spray lines is currently in 
progress by the licensee. 

ACTION TO BE TAKEN BY LICENSEES: 

For all boiling water reactors with operating license: 

1.   Complete, within 20 days of the date of this Bulletin, the inspection 
     and test program described below. The inspection should be performed 
     generally in accordance with the requirements of Appendix I of the 1974
     Edition of Section XI of the ASME Code, except that volumetric 
.

                                 - 2 - 

examination should cover a distance of one pipe radius on each side of the 
of welds. Where necessary for evaluation or confirmation of ultrasonic 
indications, supplementary examination techniques shall be used. 

a.   Examine all circumferential welds in each core spray loop up to and 
     including the valve-to-pipe weld in the second isolation valve from the
     reactor pressure vessel. 

     Conduct a system functional test or hydrostatic test on the core spray 
     system piping beyond the second isolation valve. 

b.   Select for examination a representative sampling of the pressure 
     retaining welds in austenitic piping that is a part of the reactor 
     coolant pressure boundary. This sample should include a minimum of two 
     selected circumferential welds in one loop of each of the piping 
     systems (as applicable to your facility) listed below, and two selected 
     circumferential welds in each representative branch piping run of 
     greater than 2" nominal pipe size in those piping systems listed below.
     
     1)   Main recirculation piping, including jet pump riser. 

     2)   Low pressure coolant injection system. 

     3)   Reactor head spray system. 

     4)   Control rod drive return system. 

     5)   Standby liquid poison system. 

     6)   Reactor cleanup system. 

     7)   Reactor feedwater system. 

2.   Notify this Office by telephone within 72 hours and in writing within 
     10 days of your schedule for conducting the examinations and tests 
     described in 1 above. 

3.   Notify this Office within 24 hours (with written confirmation within 10
     days) of their completion, of the results of the examinations and tests
     conducted in response to this Bulletin. A copy of the written 
     notification of examination results (including all enclosures) should 
     be sent to the Assistant Director for Construction and Operations, 
     Office of Inspection and Enforcement, Nuclear Regulatory Commission, 
     Washington, D. C. 20555. 
.

                                  - 3 -

We would also appreciate your comments regarding the significance and 
resolution of the problems involving the several cracks which have been 
revealed in boiling water reactor piping systems in recent months. 
Page Last Reviewed/Updated Tuesday, July 23, 2013