United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-56: Operability of Required Auxiliary Equipment

                                                            SSINS No.: 6835 
                                                            IN 83-56       

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF INSPECTION AND ENFORCEMENT
                           WASHINGTON, D.C. 20555
                                     
                               August 26, 1983

Information Notice No. 83-56:   OPERABILITY OF REQUIRED AUXILIARY 
                                   EQUIPMENT 

Addressees: 

All nuclear power facilities holding an operating license (OL) or a 
construction permit (CP). 

Purpose: 

This information notice is provided as a notification of a potentially 
significant problem pertaining to operability of required auxiliary 
equipment. The event described below illustrates the need to identify 
equipment whose operability is required to support the operation of 
safety-related systems. It is expected that recipients will review this 
information notice for applicability to their facilities. No specific action
or response is required. 

Description of Circumstances: 

Baltimore Gas and Electric Co. notified the NRC about an event on May 27, 
1983 at Calvert Cliffs Unit 1 in which both emergency core cooling system 
(ECCS) room air coolers were out of service for 22 hours. The coolers could 
have been required to support long term operation of engineered safety 
feature pumps under accident conditions. The coolers were removed from 
service for routine maintenance. Following this equipment outage, 
calculations performed by the licensee questioned the ability of the 
safety-related equipment located in the two ECCS rooms to perform their 
required functions in case of an accident because of temperature 
limitations. The equipment included all high-pressure safety injection, 
low-pressure safety injection, and containment spray pumps (Ref. LER 
50/317-83/028). 

The definition of "operable" and "operability" as quoted from Standard 
Technical Specifications is as follows: 

     "A system, subsystem, train, component, or device shall be OPERABLE or 
     have OPERABILITY when it is capable of performing its specified 
     function(s). Implicit in this definition shall be the assumption that 
     all necessary attendant instrumentation, controls, normal and emergency
     electrical power sources, cooling or seal water, lubrication, or other 
     required auxiliary equipment that are required for the system, 
     subsystem, train, component, or device to perform its function(s) are 
     also capable of performing its function(s)." 


8308040035 
.

                                                            IN 83-56       
                                                            August 26, 1983 
                                                            Page 2 of 2    

In the context of the above definition, the ECCS room coolers may have 
represented "required auxiliary equipment" and, if so designated, they 
should have been maintained operable to the same, extent as the equipment 
that they supported. 

Other auxiliary equipment may be required for these and other safety-related
equipment to perform their functions. Licensees are reminded that "required 
auxiliary equipment" should have already been identified and such equipment 
should be maintained in the same high state of operability as the 
safety-related equipment it supports. 

No written response to this information notice is required. If there are 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 Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contact:  M. S. Wegner, IE
                    (301) 492-4511

                    D. H. Jaffe, NRR
                    (301) 492-8140

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