4.3.3 Methods to
detect and remedy human errors
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.