4.0 Summary of Major DCISC Review Topics, 17th Annual Report - July 1, 2006 thru June 30, 2007
4.4 Human Performance: Human Errors and Improving Safety and Efficiency of Plant Performance
4.4.1 Overview and Previous Activities
Human Performance is usually used to refer to "human error" and the term is used herein in that manner. The issues around plant safety and plant efficiency having to do with human error reduction are also included in this section.
The goal of the human performance program is to reduce the number of human errors to improve plant safety and plant efficiency by improving human performance.
In past reporting periods the DCISC included the following topics in their review under “Human Performance” at DCPP:
- Human Performance Improvements
- Human Performance Overview
- Human Performance Initiatives
- Management Observations Program
- Human Performance and DCPP Business Plan
- Corrective Actions for Human Performance Improvement
- Human Performance Improvement for Engineering
In previous periods, progress in reducing human errors was evident. The DCISC concluded that it appeared that DCPP was moving positively in making improvements in the Human Performance area and has acquired experienced personnel to enhance that process. DCPP Engineering was taking a pro-active approach to reducing human errors in engineering functions.
4.4.2 Current Period Activities
During the current period (2006-2007) the DCISC reviewed the following human performance-related items:
- Human Performance
- Mispositioning Errors
Human Performance
The DCISC Fact-finding Team met with Cary Harbor, Manager Problem Prevention and Resolution, for an update on DCPP Human Performance at the March 21-22, 2007 Fact-finding Meeting (Volume II, Exhibit D.7, Section 3.5).
Human Performance (HP) has improved at DCPP as shown by the following:
| Year | Number of Event-Free Human Performance Clock Resets |
|---|---|
| 2003 | 14 |
| 2004 | 10 |
| 2005 | 7 |
| 2006 | 4 |
| 2007 (to date) | 0 |
Similar trends are shown in the Plant Improvement Report Human Errors charts. DCPP has set their 2007 goal at 2 and notes that INPO best plants have 0 or 1 Event-Free Day (EFD) resets per year.
A Utility Service Alliance (USA) Human Performance Assist Visit took place at DCPP in late 2006. The team looked at seven Organizational Factors and six Job Site Conditions in assessing DCPP human performance. Positive observations included the following:
As part of their response to the assessment, DCPP developed its Error Prevention Tools Standards document in January 2007. Its purpose it to "define standards and expectations for the use of specific Error Prevention Tools (EPTs) at DCPP with the goal of improving plant performance by reducing human error and eliminating plant human performance events". Roles, responsibilities, standards and expectations are described as well as the "whens" and "hows" of using EPTs.
The document is a comprehensive collection of the following Fundamental EPTs:
| Fundamental EPTs | |
|---|---|
| - Task Preview | - Self-Checking (STAR: Stop, Think, Act, Review) |
| - Two Minute Rule | - Procedure Use and Adherence |
| - Questioning Attitude | - Three-Way Communication |
| - Stop When Unsure | - Phonetic Alphabet |
| The following Conditional Tools are included: | |
| - Pre-Job Briefing (Tailboard) | - Flagging |
| - Verification Practices | - Place keeping |
| - Concurrent Verification | - Turnover |
| - Independent Verification | - Post-Job Review |
| - Peer-Checking | |
The recent Utility Service Alliance (USA) Human Performance Assist Visit to DCPP found some gaps in DCPP’s expectations and use of Error Prevention Tools (EPTs) and procedure quality which could have adverse effects on human performance. DCPP has responded appropriately with its Error Prevention Tools Standards which addresses many of the USA recommendations and should enhance error prevention. Procedure upgrades are underway.
Mispositioning Errors
The Fact-finding Team met with James Edwards, DCPP Operations Support Manager, at the March 21-22, 2007 Fact-finding Meeting (Volume II, Exhibit D.7, Section 3.6) to discuss the status of mispositioning errors (MEs which are errors causing components (mostly valves and relays) to be left in a nonconforming position usually following test or maintenance.
DCPP experienced a relatively high number of MEs during Outage 2R12. MEs were the subject of a January 29, 2006 Outage 2R13 Quality Verification Audit which stated that DCPP would be unable to achieve top level performance until mispositioning and procedure non-adherence (one of the main causes of mispositioning) issues were addressed and improved. Mispositioning errors increased in July and August 2006, and the issues were again raised in the Quality Performance Assessment Report (QPAR). Management attention has been directed to the issue. Both NRC and INPO had concerns regarding mispositioning.
DCPP performed a root cause analysis as a result of writing a Nonconformance Report (NCR). It also compared mispositioning error data with other plants. Since 2003, DCPP’s ME trend has shown the following results:
| Type of Error | Trend | Number Events in 2006 |
|---|---|---|
| Consequential | Improving | 6 |
| Non-Consequential | Little Improvement | 23 |
| Clearance Issues | Improving | 4 |
| Near Miss Reports | (Too little data) | 15 |
Analysis of the event data showed the following breakdown of causes:
| Organizational Weaknesses | 45% |
|---|---|
| Standards and Expectations | 55% |
| Quality of Documentation | 38% |
| Management Systems | 7% |
| Leadership practices | 35% |
| Communication | 60% |
| Monitoring | 40% |
| Individual practices | 20% |
| Self-Verification | 56% |
| Independent Verification | 44% |
Corrective Actions are:
- Management Ownership and Institutionalization
- Develop station and department-level human performance plans
- Develop a system to analyze, trend and utilize HP data
- Standardize communication practices across the station
- Implement best-practices for management observation programs
- Implement best-practices for supervisory effectiveness programs
- Integrate measures and metrics into SAP
- Evaluate the effectiveness of documentation improvement efforts
- Implement station-wide verification practices that meet or exceed the standards set forth in INPO AP-931, “Verification Practices”
(Note: these corrective actions are being implemented along with those which resulted from the USA visit in the above section Human Performance.)
DCPP had already begun identifying low-level errors and error precursors and is including them in its measures rollup process. They have also initiated procedure changes for human factors.
DCPP has established a Mispositions Performance Indicator, which tracks occurrences on a monthly basis, based on a goal of 100, from which points are deducted as determined by severity of the potential consequences of a misposition occurrence.
A consequential mispositioning occurred during refueling outage 1R14 when an inadvertent water transfer from the Reactor cavity to the Refueling Water Storage Tank (RWST) took place when a valve was mispositioned and the correct valve was not positioned correctly. The Operations Review Team determined the event had two root causes: loss of focus during a tailboard briefing concerning a repetitive task; and mistaken identification of the valve which was manipulated. An Operations Awareness bulletin was issued for this event to emphasize the need to review the description rather than just looking at a valve number. During 1R14 a consistent message was sent to the Operations workforce that if an unexpected condition was discovered in the plant, the proper procedure is to resolve the question before continuing to perform the work.
DCPP uses the concept of a human performance clock reset, on both a departmental and a site-wide basis, to gauge progress on human performance and stated that consequential mispositionings result in a clock reset, while non-consequential occurrences do not.
There have been three non-consequential mispositionings resulting in a one-half point deduction each from the Performance Indicator for:
- Air valve to MSR dump valve found closed (Unknown).
- Clearance problem during RTS (Operations).
- FWP-1 filter found closed (Operations).
Outage 1R14 represented the best outage performance relative to Operations errors for DCPP, with a total of 3 errors, attributed to operators’ use of the human performance tools developed to reduce error. Errors tend to occur at the beginning and end of refueling outage periods.
There were six noteworthy errors in Outage 2R13, not all of which were due to mispositioning. Operations department-level events during 1R14 included:
- Danger tag found on a "closed" disconnect switch.
- Inadvertent water transfer from U-1 cavity to RWST.
- Clearance hung with a danger tag “open” on a valve.
DCPP believed that the nine noteworthy errors from 2R13 and 1R14 did not appear to indicate a common theme or precursor. The Operations Review Team evaluates each event for consequences and issues an operator bulletin within 24-hours of any Operations department-level event. An INPO-identified Area for Improvement (AFI) is related to mispositioning and the related need for clear standards and procedural adherence. The NRC is interested in every mispositioning event at DCPP.
DCPP has taken aggressive, appropriate corrective actions to improve Operations human performance regarding mispositioning errors. The DCISC will follow up on action implementation and results.
4.4.3 Conclusions and Recommendations
- Conclusions:
- DCPP continues to improve its Human Performance Program by implementing more explicit and understandable expectations, standards and tools to prevent human errors and, in particular, by focusing on mispositioning errors.
- Recommendations: None