Resolution of Generic Safety Issues: Issue 102: Human Error in Events Involving Wrong Unit or Wrong Train (Rev. 2) ( NUREG-0933, Main Report with Supplements 1–34 )
In January 1984, AEOD issued a special study report (AEOD/S401)640 describing the number of events that resulted from human error in identification of the correct unit or train. This study focused on LERs issued during 1981, 1982, and part of 1983.
Although the scope of its study was narrow, AEOD found that 19 out of 27 events identified resulted from human error during maintenance and surveillance testing; 16 of these occurred while the plants were at power. Although most of the events had limited safety significance because of the short duration of the condition and/or because redundant systems were operable and available, AEOD considered them to be examples of events that could have high safety significance under other circumstances. As a result, AEOD concluded that the above statistic was evidence that human errors in maintenance and testing operations are major contributors to loss of safety system events. Following the issuance of the AEOD report,640 Information Notice Nos. 84-51641 and 84-58642 were issued to alert licensees to the potential problem.
Safety functions can be inadvertently defeated by human errors involving the wrong unit, wrong train, or wrong system.
(1) Consider the need for further clarification and/or guidance on what constitutes an acceptable independent verification program.
(2) Review the wrong unit/train events and develop appropriate guidance to minimize such events.
(1) As part of the Maintenance and Surveillance Program Plan (MSPP), consider the high proportion of events that were due to human error in maintenance and testing operations at power.
(1) Human Error in the Performance of Maintenance
(2) Indicators of Maintenance Effectiveness
(3) Counteracting Aging Effects and the Role of Preventive Maintenance
(4) Management and Organization Impacts on Maintenance Effectiveness
(5) Maintenance Program Criteria and Standards
(6) The Maintenance and Operations Interface
AEOD Recommendations (1) and (2) outlined above are to be addressed in MSPP Technical Issues (6) and (5), respectively.645 The AEOD suggestion is covered in MSPP Technical Issue (1).645 In April 1985, the MSPP (Issue HF08) was presented to the Commission in SECY-85-129.764 Issue 102 was specifically addressed as Item 3.2.9 of the MSPP; however, in June 1986, the staff decided to pursue the resolution of Issue 102 separately from Issue HF08.990
In addressing this issue, the staff reviewed operating experience, conducted site visits, and interviewed licensee personnel to determine the nature and root causes of 35 wrong unit and wrong train events. The results indicated that the primary causes of these events were inadequate labeling of areas, equipment, and components, inadequate personnel training and experience, and inadequate procedures; these results were reported in NUREG-1192.1120 In June 1987, Information Notice No. 87-251121 was issued and reiterated the primary causes of the subject events and called for the industry to increase its attention in this area. Wrong unit/wrong train component concerns are being addressed in the broader context of the Emergency Operating Procedure Inspection program, Detailed Control Room Design Reviews, and future integrated inspections which include assessment of local control stations and maintenance programs. During discussions with INPO, subsequent to publication of NUREG-1192,1120 the staff learned that INPO reviews licensee actions to resolve this issue as part of their plant evaluations and INPO expects to continue such reviews in the future.
Based on the above staff actions and industry initiatives, NRR concluded that no further staff action was warranted.1122 Thus, this issue was RESOLVED and no new requirements were established.