4.3.3 Methods to detect and remedy human errors

Disclosing of human errors, including root cause analysis and taking of measures to prevent them from repeating in the future is an integral part of the events investigation system at nuclear installation; event investigation feedback groups are established at divisions of power plant technical support. Section 5.3.5 provides a detailed description of the events investigation process at nuclear installations. Here, only some aspects concerning human factor are described.

The efficiency of the system is being evaluated and analyzed at regular intervals by feedback group staff. The results, along with draft measures and recommendations, are included in annual reports submitted to the power plant board for approval.

Safety culture and the human factor are also important components of a comprehensive reports on the status of the nuclear and radiation safety of SE, a.s., regularly presented to the company board.

In 2000, SE, a.s. recorded a total of 49 (25% of the overall number) NIE, where human error was one of the causes, thereof 15 and 32 events at nuclear installations due to the human factor at NPP Bohunice and Mochovce units, respectively. The higher numbers of events occurring at Mochovce were due to mainly poorer operating experience of the staff (a new power plant).

On the average, the human factorś contributions is about 26% of NIE in all the three branch plants of SE, a.s. within the recent five years, thereof about one quarter of the events being due to the staff of contractors and/or external substations.

Fig. 4.3.1 Share of operating events with human error causes - overall SE, a.s.

It is evident from Figure 4.3.1 that the share of staff’s errors has been stable in recent years. The power plant staff are being briefed on a regular basis on the investigation results of NIE causes and their analyses. Moreover, such information are also available on the company’s computer networks.

To improve the safety culture and for the purposes of self-assessment, individual branch plants develop so-called action plans of safety culture, evaluated annually and presented to the boards of the branch plants for approval. Action plans are issued as Director Orders, they thus are of generally binding nature within the corresponding branch plant. Safety culture parameters have been defined for the purposes of evaluation.

A special group for self-assessment of safety culture was established at NPP Mochovce . The objective is to make the system of self-assessment more effective based on a survey within employees. The aim is besides existing instruments (newspapers, training, program STAR) for safety culture improvements to provide managers at all levels with an instrument for assessing the level of safety culture. For this purpose a set of indicators and rules for their application have been developed.

To prevent human errors, so-called program SAKO was put in place at NPP Bohunice (an analogy of the world-wide known program STAR - i.e. Stop, Think, Act, Review). The program is of a rather illustrative nature, with a fire-fly called SAMKO as logo; fliers, stickers, articles in company’s magazine, etc. are used.