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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 Attachment: List of Recently Issued IE Information Notices .
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