NEA Mandates and Structures

Technical Review Group for the International Assay Data of Spent Nuclear Fuel Database

Mandate (Document reference):

• Agreed by written procedure following the Nuclear Science Committee bureau meeting in December 2006 [NEA/NSC/DOC(2006)25]
• Extended as a part of WPNCS activities at the 21^st meeting of the Nuclear Science Committee in June 2010 [NEA/SEN/NSC(2010)3]
• Extended as a part of WPNCS activities at the 23^rd meeting of the Nuclear Science Committee in June 2012 [NEA/SEN/NSC(2012)3]
• Extended at the 16^th meeting of the WPNCS held in September 2012 [NEA/NSC/WPNCS/DOC(2013)6]
• Extended at the 19th meeting of the WPNCS held in July 2015
• Name change agreed at the 21^st meeting of the WPNCS held in June 2017, [NEA/NSC/WPNCS/DOC(2017)2]; formerly the Expert Group on Assay Data of Spent Nuclear Fuel
• Extended at the 21^st meeting of the WPNCS held in June 2017, [NEA/NSC/WPNCS/DOC(2017)2]
• Mandate of the Technical Review Group for the International Assay Data of Spent Nuclear Fuel Database (SFCOMPO) [NEA/NSC/WPNCS/DOC(2018)1]

Mandate (Document extract):

Extract from document NEA/NSC/WPNCS/DOC(2018)1

Mandate:

The Technical Review Group will review the facilities available for measurement of isotopic composition of spent nuclear fuel, especially in the OECD member countries. The Technical Review Group will also analyse the SFCOMPO database in order to assess the current situation and the need for new experimental data.

The Technical Review Group will collect new isotopic composition data from PIE and input them, and their associated operating histories/data, into SFCOMPO. It will also review the format of the SFCOMPO database. The members of the Technical Review Group will provide the interface to contact specialists in their own country and in other international communities to identify and obtain new data to be included in SFCOMPO and used by the public.

The Technical Review Group will keep and archive original reports on any PIE data included in the SFCOMPO database, and add supporting technical references that were used in the original development. The NEA Secretariat services will be used to archive the experimental reports to be made available via the NEA website.

The Technical Review Group will provide technical advice in support of PIE activities in member countries and promote international collaboration in order to compensate for the fact that few PIE data are freely available. With the help of experts, the group will identify and define the methods for obtaining the different types of isotopic composition data (experimental techniques for dissolution, separations, mass measurements, etc.). The expert group will:

1) develop criteria and procedures to assure the quality of future experiments by identifying a set of minimum requirements for fuel characterisation and operating history data to qualify samples to be used in isotopic composition measurements; and

2) update the format used in SFCOMPO and investigate and confirm the quality of experimental data already available in the database.

Scope and Objectives for the Extended Mandate

Under the guidance of the Working Party on Nuclear Criticality Safety (WPNCS), the Technical Review Group has identified the following main areas under which it will conduct activities:

• Preservation of Data: One of the main objectives of the Technical Review Group is to ensure preservation of already existing assay data, as well as continuously capturing new data as it becomes available. This is important in order to profit both from the operator and experimentalist knowledge of the conditions under which samples and measures were obtained, before such information is lost.
• Accessibility of Data: Experimental data are made accessible to users in a standardised format through the database SFCOMPO. As new parameters are identified by the Technical Review Group as required fields of a complete evaluation, the database and its interface tools will have to be adapted accordingly.
• Evaluation of Assay Data: This significant and challenging objective seeks complete documentation of data sets, including all relevant design and reactor operating data, as well as an independent, peer-reviewed assessment of these data. This review process is intended to vet the data for potential errors and produce qualified data suitable for use in code validation.
• Knowledge Transfer: Guidance for the qualification of the evaluation of isotopic assay data will be developed by the Technical Review Group. Similar guidelines have already been established for the qualification of benchmark data by the International Criticality Safety Benchmark Evaluation Project (ICSBEP) for criticality experiments, and by the International Evaluated Reactor Physics Experiments Evaluation Project (IRPhE) for reactor physics benchmarks.

Deliverables

• Yearly update and maintenance of the SFCOMPO database, which includes the following tasks:
  • Collect, capture, format, and include new experimental assay data;
  • Provide input models for selected data to assist future evaluations of the data;
  • Expand the type of assay data included in SFCOMPO database (open to discussion).

Meeting frequency

The Technical Review Group will meet on average once per year.

Links to other NEA bodies

Because of the importance of the assay data to many different areas of spent fuel management, the Technical Review Group consists not only of the WPNCS members representing nuclear criticality safety, but also members of the Committee on the Safety of Nuclear Installations (CSNI) and the Integration Group for the Safety Case (IGSC), the main technical advisory body to the Radioactive Waste Management Committee (RWMC) on the deep geological disposal of long-lived and high-level radioactive waste.