Transmittal of Information on NRC "Nuclear Data Link Specifications" (Generic Letter 80-24)

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

                                March 12, 1980 




In response to the Kemeny Report, established to investigate the accident at
the Three Mile Island Unit 2 nuclear plant, on December 7, 1979, the 
President issued a number of actions to improve the safety of nuclear power 
plants. Included in these actions was for "the NRC to evaluate the need for 
a federal presence in the control room of operating reactors, such as by 
observers or continued computer monitoring of vital plant parameters."  The 
staff believes that the most effective and timely response to the announced 
initiative would be to continue in its evaluation of a computerized 
monitoring system of vital plant parameters. 

The staff is currently engaged in improving the capabilities of its NRC 
Operations Center (OC) at Bethesda, Maryland, in order to provide the 
Commission and senior staff members with vital plant parameters and 
information from licensed nuclear plants in the event of incidents or 
accidents.  Improved capabilities which are under consideration for the OC 
will include automatic data processing, data storage, data display and data 
recall capability to be achieved through the use of digital computer.  The 
overall objective for obtaining such information is to enable the NRC, in 
the event of a nuclear accident at a licensed reactor facility:  (1) to 
monitor and evaluate the situation and potential hazards; (2) to advise the 
licensee's operating staff as needed; and (3) in an extreme case, to be able 
to issue orders governing such operations. 

A system study of a digital computer based Nuclear Data Link (NDL) to bring 
this type of information from nuclear plants to the OC has been instituted 
with Sandia Laboratories.  The system study has been directed toward digital
communication systems because of the proven availability of the technology 
and the successful, reliable, operating experience, and the operating costs 
of well designed systems in the business community.  The goal is to achieve 
an initial operating capability to receive, process, display, evaluate and 
record essential, but limited, data at the new OC installation by January 1, 
1982.  A subsequent program will delineate improvement and refinements to 
the system. 

The data which are being considered for acquisition, transmission, receipt 
and display will consist of those plant parameters required to evaluate the 
status of the core cooling process.  Furthermore, event data, status of 
safety-related systems and radiological data would also be transmitted for 
purposes of evaluating licensee's actions, safety of the plant, and 
radiological releases.  In our opinion, the quantity of data to be 
transmitted by the link is a small fraction of the total data required to 
operate and control the plant. 

The purpose of this letter is to advise you of the foregoing and to 
encourage your cooperation and participation to ensure timely completion of 
the evaluation of the NDL.  It is also recognized that several related 
programs are also being implemented based upon the results of the NRC 
Lessons Learned Task Force Reports (NUREG-0578 and -0585); e.g., the Onsite 
Technical Support Center (OSTSC) and Control Room Evaluation.  These actions 
will interface with the NDL and the OC.  It is apparent that close 
coordination is needed between the requirements being established for the 
NDL and those of the OSTSC and therefore improved control rooms at 
individual plants. 

To fully understand the plant parameter data systems presently in use at 
each nuclear plant, the staff through the Office of Nuclear Regulatory 
Research and the Sandia Laboratories will conduct a survey over the next six 
months.  The results of this survey will then be used to finalize the 
specifications for an NDL such as digitized data access protocol and 
transmission link design requirements.  The immediate objective will be to 
select lead plants and data to ensure early and meaningful operation of the 
NDL.  A copy of the initial NDL specifications is enclosed for your 
information.  The data protocol will be a fixed format data matrix that 
would be transmitted by all plants. Initially, blanks would be transmitted 
where data access is not available at a given plant.  Subsequent actions by 
licensees would be to upgrade their capability to complete the data protocol 
and ensure uniform digitized computer data capability from each nuclear 
plant to the OC. 

We will keep you advised of our progress in the NDL program.  We are 
presently in contact with members of INPO who are helping in establishing 
basic requirements. 

We appreciate your help and cooperation and your personal assistance in our 
deliberations to date and solicit your continued support in this important 

                                      Darrell G. Eisenhut, Acting Director 
                                      Division of Operating Reactors 

Nuclear Data Link Specifications
  February 21, 1980 


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