Statement on the letter of the ESK/SSK Asse Ad-hoc Working Group

On account of unclear reports in the media, BfS again points out that a large number of objections raised and suggestions on the topic of Asse which were made by the Ad-hoc Working Group of the Waste Management Commission/Commission on Radiological Protection (ESK/SSK) and by Mr Michael Sailer have already been taken into account in the result of the comparison of options. BfS is also of the opinion that not enough time for recovering each drum has been calculated in the feasibility study for retrieval of the waste. Therefore, BfS has taken into account additional time for the comparison of options. Other than has partially been communicated in the media, the result of the comparison of options does not assume a time of four or, respectively, 4.8 minutes per drum.

Furthermore, BfS plans – in account with the ESK/SSK – to open individual chambers to obtain certainty about the state of the drums and, thus, to arrive at a more realistic estimation of the time required. The statement of the ESK/SSK of 5 January does also not refer to the result of the comparison of options but to an interim state in the process of discussion. This can also be seen from the fact that the ESK/SSK based their statement on results of meetings of the Ad-hoc Working Group of ESK and SSK, which had taken place before the comparison of options was completed.

On 18 January, BfS made a detailed statement on the statement by ESK/SSK:

Within the scope of accompanying the process of comparing options for decommissioning the Asse II mine, BMU had requested the ESK/SSK ASSE Ad-hoc Working Group to write down their opinions about the options and about step 1 of the comparison of options (feasibility studies and characterisation of options), which was presented to the Asse II Accompanying Group by BfS. The ESK/SSK Ad-hoc Working Group dealt with the options and submitted their opinion to BMU in a letter dated 5 January 2010. BfS gives the following statement on this issue:

The statement is mainly based on an evaluation of the three feasibility studies ordered by BfS and on the characterisation of the individual decommissioning options (phase 1 of the comparison of options) presented by BfS. For reasons of time, the Working Group was not able to evaluate the actual comparison.

The notes of the Working Group regarding content, have already been integrated in the result of the comparison of options presented by BfS on 15 January 2010.

If they are not out-dated, the specialist assessment of the decommissioning options and the recommendation for the further approach by the ESK/SSK Ad-hoc Working Group are not suited for generally calling in question the statements and results of the BfS comparison of options. In many cases, they correspond with the statements made by BfS in the report on the comparison of options.

There are some single points where the working group arrives at conclusions which are not shared by BfS. This includes, for example, the question whether the decommissioning options can only be compared after an Integrated Emergency Plan will be available. In the opinion of BfS, such a plan is required for the implementation of each individual decommissioning option but not for performing a comparison of the specific pros and cons of the individual options.

Furthermore, the ESK/SSK ASSE Ad-hoc Working Group identified and evaluated uncertainties of individual decommissioning options, referring concretely to the options of retrieval or relocation, respectively. In the ESK letter, concrete measures for the further approach derived from this are recommended. Part of the mentioned uncertainties and suggested measures were discussed and taken into account in a similar way by BfS when the report on the comparison of options was drafted. As a result, the option of retrieval is considered the best of the examined variants. Just like the ESK/SSK Working Group, BfS arrives at the conclusion that at first some emplacement chambers need to be opened and selected waste packages taken out and examined for their quality and content.

However, BfS does not arrive at the conclusion that there is a considerable probability that solely the concept of complete backfilling will prove to be realisable. BfS rather points out that there is insufficient data available relating to complete backfilling. As regards this decommissioning option, it is currently not possible to prognosticate whether it will be possible to furnish proof of long-term safety.

BfS considers the implementation of a comparison possible and necessary, also in view of the currently available data part of which is incomplete.

The following issues need to be emphasised as essential and fundamental statements on the comparison of options, the uncertainties and deficiencies in knowledge, and the recommendation for the further approach:

• The feasibility studies for the decommissioning options are indeed limited in depth, and partial aspects are incomplete. Nevertheless, on the basis of the additionally available documents and information, a comparison of decommissioning options is possible at present. It would, however, take many months, if not years, to complete the studies and to resolve the deficiencies in knowledge. Irrespective of this, due to the shortage of time and the risk of a further negative change of the situation in Asse, quick action and rash decisions on the basis of the information which is available or can be gained within short time, are necessary. It is absolutely necessary to realise concrete steps as soon as possible and to swiftly tackle the issue of decommissioning the Asse mine. The existing uncertainties need to be considered in the weighting and in the decision-making process.
• The option “complete internal relocation” need not be pursued further because of the necessary exploration phase which would take several years and whose result is uncertain as to whether a suitable relocation horizon can be found.
• For the option of retrieval it is essential what state the emplaced packages are in and what technical effort it would require to recover them. In this respect, uncertainties currently exist affecting also the required time and the radiation exposure to the staff. Therefore, it is necessary to open some emplacement chambers and to take out selected waste packages and examine them with respect to their quality and content. For this purpose, it is intended to evaluate beforehand all available information relating to this topic and, subsequently, take a decision about possible sites where waste packages to be examined can be taken out and the extent of these packages.

In their essential points, the statements made correspond with the appraisement of BfS and support the further approach suggested by BfS. An Integrated Emergency Concept is currently being developed. As soon as possible, BfS will substantiate the plans for retrieval of the waste up to the point where they will be ripe for implementation. Examinations on the state of the geological formation and long-term safety considerations are being intensively advanced.

BfS is of different opinion about some more details of the ESK/SSK ASSE Ad-hoc Working Group statement, respectively, it is necessary to put some things straight, which are outlined in the following:

The view of the ESK/SSK Ad-hoc Working Group that a partial retrieval of the waste cannot improve the situation with respect to long-term safety considerations is not shared by BfS under the present circumstances. From the BfS point of view, further examinations and/or calculations are necessary for a substantiated appraisement, in order to quantify the contribution of individual emplacement areas and/or types of waste packages to the entire radiation exposure to future generations.

The ESK/SSK ASSE Ad-hoc Working Group considers the time frame given in the feasibility studies for the retrieval and relocation and, in particular, the recovery of the waste not plausible, since it is based on optimal conditions for the technical implementation and the licensing procedure. Basically, BfS shares this opinion. Therefore, for lack of additional reliable information, the scheduled time required was increased by 25 % in the comparison of options. The criticism of the ASSE Ad-hoc Working Group that this approach was not comprehensible, not appropriate, and not sufficient for a realistic scheduling, cannot be followed insofar. It needs to be clarified that BfS has not claimed realistic scheduling with regard to time in the comparison of options but has expressly pointed out that the times given in the feasibility studies were considered unrealistically optimistic and not realisable. On the one hand, this is made clear through the chosen additional factor of 1.25. From the BfS point of view, a more realistic estimation of the time required can only be achieved after further knowledge has been gained with respect to the actual state of the waste packages, and after further concrete plans have been made for the technical implementation of the recovery and retrieval of the waste from the Asse mine.

The ESK/SSK ASSE Ad-hoc Working Group doubts that sufficient and reliable ventilation for open handling of radioactive substances, as would be required for retrieval, can be ensured in a one-shaft facility. According to the present state of knowledge, BfS cannot share this opinion without reservation. Those who carried out the feasibility study on retrieval have sketched a concept which is to ensure sufficient ventilation of the facility during retrieval operations, even with one shaft. This ventilation concept is based on a minimisation of the amounts of air in the off-limits or in the control area, among others by using electric vehicles. From the BfS point of view, this approach appears to be plausible and productive in the first instance, since a clearly increased amount of air would also require considerable exhaust air decontamination and filtering. In the opinion of BfS, a final evaluation as to whether an additional ventilation shaft is necessary for providing the required amounts of air when retrieving the waste from the Asse mine, can only be made when advanced concept and implementation plans for the technical implementation of the recovery and the required ventilation and filter systems are available.

In summary, it is to be stated that the ESK/SSK Ad-hoc Working Group gave a number of suggestions and notes, parts of which have positively been integrated in the BfS report, the other part – as shown above – being classified as not relevant to the result. In the phase of public discussion following the presentation of the result on 15 January 2010, the BMU advisory boards will certainly also deal with the result.