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HomeNRC LibraryDocument CollectionsGeneric CommunicationsInformation Notices1979

# Information Notice No. 79-26, Breach of Containment Integrity  

```
IN79026 

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                          WASHINGTON, D. C. 20555 
                                     
                             November 1, 1979 

MEMORANDUM FOR:     B. H. Grier, Director, Region I 
                    J. P. O'Reilly, Director, Region II 
                    J. G. Keppler, Director, Region III 
                    K. V. Seyfrit, Director, Region IV 
                    R. H. Engelken, Director, Region V 

FROM:               Norman C. Moseley, Director, Division of Reactor 
                      Operations Inspection, IE 

SUBJECT:            Information Notice No. 79-26, BREACH OF CONTAINMENT 
                    INTEGRITY 

The subject document is transmitted for issuance on November 5, 1979. The 
Information Notice should be issued to all power reactor facilities holding 
operating licenses and construction permits. 

Also enclosed is a draft copy of the transmittal letter. 


                                        Norman C. Moseley, Director 
                                        Division of Reactor Operations 
                                          Inspection 
                                        Office of Inspection and Enforcement

Enclosures:
1.   IE Information Notice
       No. 79-26
2.   Draft Transmittal Letter

CONTACT:  P. F. McKee, IE 
          49-28019 
.

(Transmittal letter for Information Notice No. 79-26 to each holder of an 
NRC Operating License and Construction Permit.)  

                                           Information Notice No. 79-26 

Addressee: 

This Information Notice is provided as an early notification of a possibly 
significant matter. It is expected that recipients will review the 
information for possible applicability to their facilities. No specific 
action or response is requested at this time. If further NRC evaluations so 
indicate, an IE Circular, Bulletin, or NRR Generic Letter will be issued to 
recommend or request specific licensee actions. If you have questions 
regarding the matter, please contact the Director of the appropriate NRC 
Regional Office. 


                                        Signature 
                                        (Regional Director) 

Enclosures:
1.   Information Notice No. 
       No. 79-26 
2.   List of IE Information 
       Notices Issued in the 
       Last Six Months
.

                                                              SSINS:  6870 
                                                              Accession No: 
                                                              7908220133   

                              UNITED STATES  
                      NUCLEAR REGULATORY COMMISSION 
                  OFFICE OF INSPECTION AND ENFORCEMENT  
                         WASHINGTON, D. C. 20555  
                                     
                            November 5, 1979  

                                           Information Notice No. 79-26 

BREACH OF CONTAINMENT INTEGRITY 

Description of Circumstances: 

On September 14, 1979, the Consumers Power Company (CPC) notified the NRC of
discovery at the Palisades Nuclear Generating Plant of a valve misalignment 
that had resulted in containment integrity being breached for an 
indeterminate length of time. 

While preparing to perform a Type "C" leak test between two manual valves in
a 3" bypass line around the main 48" containment purge valve, plant 
personnel discovered that both of these manual isolation valves were locked 
in the open position. These valves should have been locked closed. 
Investigation by the licensee indicated that the valves may have been 
improperly positioned since April, 1978, when an efficiency test of the 
bypass line filters was performed. The plant has operated at power for the 
major portion of that time period. 

The valve misalignment had no actual impact on the public health. However, 
in the event of a design basis accident wherein fuel damage and release of 
primary coolant inside the containment are postulated, the open valves would
provide a significant path for a radioactive release from the containment. 

The initial design purpose for the bypass system was to provide a long term 
hydrogen control capability for the containment atmosphere following a 
design basis accident.1  It was intended that after approximately 30 days 
following an accident, when containment pressure and activity levels dropped
sufficiently to permit venting, this system would be manually valved to vent
the containment atmosphere, through high efficiency and charcoal filters, to
the exhaust stack. Thus the components in the bypass line beyond the two 
manual isolation valves were not designed for the severe service they would 
be exposed to with the valves open during the initial pressure surge of the 
design basis accident, and significant uncontrolled release would result. 
High radiation in the vicinity of the bypass line would also make immediate 
closing of the manual isolation valves, even if identified as the source of 
leakage, an extremely hazardous operation. 

The principal cause for this event was inadequacy of the procedures 
addressing proper use and positioning of these valves. The master 
containment integrity valve line-up checklist, which is performed prior to 
each startup from cold 
________________________________ 
 1/ Current NRC requirements call for the use of hydrogen recombiners to 
 control hydrogen buildup. Palisades has recombiners installed. 
.

Information Notice No. 79-26                            November 5, 1979 
                                                           Page 2 of 2     

shutdown, did not include these valves.  The filter efficiency test for the 
3" bypass line did not adequately specify the final position of these 
valves, and this is the probable cause for the valves being left incorrectly
positioned.  The valve misalignment represents a case where human factors in
the form of inadequate procedures resulted in a loss of safety system 
function. 

CPC has updated the above mentioned procedures to assure that proper 
positioning of these valves is addressed. Concurrently, CPC is reviewing 
other paths from containment to assure that procedures and checklists are 
complete. CPC has also hired a qualified consultant to perform an 
independent review for the same purpose. 

This Information Notice is provided as an early notification of a 
significant occurrence. It is expected that recipients will review the 
information for possible applicability to their facilities. No written 
response is required. If you desire additional information regarding this 
matter, contact the Director of the appropriate NRC Regional Office. 
.
```

*Page Last Reviewed/Updated Friday, May 22, 2015*

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