[en] A complete safety analysis is performed every 10th year for each nuclear power reactor in Sweden. NIRP review the radiation protection conditions. Analyses of different areas gives the status of the radiation protection activities at the reactor unit and points out which fields will require most attention in the nearest future. 6 figs. (Author)

[en] The objective of the strategy for CDA is to obtain information as soon as possible and to continue the assessment until stable conditions are established. CDA methods are: 1) information of process parameters; 2) dose rates within the containment; 3) activity content (Swedish post accident sampling system PASS); 4) hydrogen concentration. (orig.)

[en] During the outage 2003 at Forsmark unit 2 it was planned to make a modification to the moist separator (an internal part of the reactor vessel.), see Figure 1. The work was initiated due to extensive cracking found in welds, which challenged the mechanical integrity of the moist separator and also loose parts lost in the reactor vessel. The cracks had been known for several years but until now no measures were deemed necessary. (authors)

[en] Due to national regulations, all Swedish nuclear power plants are provided with filtered containment venting. Strategies for severe accident management have also been developed and implemented. A question of greatest importance for adequate accident management is the extent of core damage. The answer to that question may influence actions to be taken, in the short term as well as for long term actions, and it is also essential when estimating environmental consequences of an automatic or deliberate containment venting. The objective of the strategy for core damage assessment (CDA) is to obtain information as soon as possible and to continue the assessment until stable conditions are established. It is recognized that methods available immediately after the onset of an accident are mainly indicative and fairly imprecise. More detailed and accurate information can be obtained in the longer time span. A specific example of implemented procedures for Core Damage Assessment (CDA ) is given. Methods to judge the core damage include: dose rate readings in the containment, post accident sampling system, process parameters, hydrogen concentration. The first two methods are quantitative, in particular the post-accident sampling system. The process parameters can be used as a source of information if the core has been uncovered. The hydrogen measurements can only be used as a supportive argument confirming that zircaloy oxidation has occurred. It is pointed out in the discussion that the uncertainty on the amount of hydrogen generated is important, but that an equally important uncertainty is the possibility of hydrogen stratification in the containment. Thus, the importance of having a sufficient number of hydrogen sensors is stressed