Seminars

Scheduled meeting of Scientific and Technical Council of SEC NRS was held

The issues considered

1. Consideration of the methodological document “Methodology for express-evaluation of release source-term in case of accidents at VVER-1000 types power units (B-320 project)”.
2. Individual plan of postgraduate student G.R. Pipchenko.
3. Regarding implementation of Scientific and Technical Council decisions for the year 2014.

On the first issue

Having heard and discussed the presentation made by Albert S. Shapovalov, Head of laboratory on assessment and forecasting of radiological consequences of nuclear facilities accidents (Nuclear and Radiation Safety Division) and after speaking in debates,

STC has noted that

In the correspondence with Order of Rostechnadzor No. 760 from October 18, 2005, one of the main tasks of the functional subsystem on monitoring over nuclear- and radiation hazardous facilities is provision of Rostechnadzors’ readiness status to response in case of emergency situations at nuclear- and radiation hazardous facilities, wherefore in the event of accident the monitoring of activities to be performed by the Operating Organization (hereinafter to be referred to as – the OO) on localization and elimination of emergencies shall be envisaged and, in particular, monitoring over activities taken by the OO to forecast the radiological situation against the possibility of NPP accident and to evaluate the necessity to implement urgent protective measures.

Aiming to perform this function in accordance with “Provision on Information and Analytical Center of Federal Environmental, Industrial and Nuclear Supervision Service” approved by Order of Rostechnadzor No. 165, dated April 18, 2013, the Information and Analytical Center (hereinafter in text to be referred to as – IAC of Rostechnadzor) includes working groups of management staff and specialists from Rostechnadzors’ Headquarters and SEC NRS to assess and forecast the technological condition of a nuclear facility and to provide prognosis of radiological environment there. Computational tools are necessary for the mentioned groups’ activities, which enable them in the event of accident situation, occurred at NPP or when implementing emergency drills and exercises to comply promptly with appropriate assessment and prognosis independently from the OO.

As far as the initial period of accident progression is concerned, not all source data are known (NPP unit current status performance parameters) that are necessary for the detailed calculation of emergency release and for that reason the uncertainty of radiological consequences with respect to the probable accidents evaluated owing to application of such computational tools will be very great. Due to the fact that such calculations are time consuming, they are not effective for the monitoring over the OO activities fulfilled to assess the necessity to implement urgent protective measures. The corresponding express- evaluations are more appropriate for that.

In the perspective to develop such methods within the frames of Action No.326 of the Federal Target Programm “Provision of Nuclear and Radiation Safety for the Year 2008 and up to 2015”, last year SEC NRS implemented R&D titled “Evaluation of parameters of NPP emergency releases with the purpose to develop methodological support to Information and Analytical Center of Rostechnadzor”. Following the safety case of VVER-1000 type units (of B-320 project) prepared by the OO, this R&D specified pathways (scenarios) for radioactive substances release into atmosphere through power unit physical barriers totality (fuel rod cladding, primary circuit , etc. up to the last barrier, which separates radioactive medium from atmosphere) and proposed the evaluation algorithm in respect to the emergency emissions at such scenarios origination. This algorithm is based on the fact that activity of every radionuclide within the emission is directly proportional to its activity accumulated in core and/or in primary coolant and the coefficient of proportionality is equal to the product of the coefficients which characterize the activity share of each radionuclide that is “released” through the appropriate physical barrier. These coefficients were defined with taking into consideration approaches provided by the IAEA document “Generic Assessment Procedures for Determining Protective Actions during a Reactor Accident” (TECDOC-955).

The methodology on emergency emissions evaluation in the event of accidents at VVER-1000 type reactor (of B-320 project) had been produced using these results of this R&D.

In the correspondence with the R&D outcomes draft methodological document “Methodology for express-evaluation of release source-term in case of accidents at VVER-1000 types units (B-320 project)” was prepared. Its application in case of accident at VVER-1000 type NPPs and in conducting of exercises and drills at IAC of Rostechnadzor within implementation of para. 9 of “Actions Plan on Improvement of Performance Effectiveness Regarding the Monitoring System over Nuclear Facilities in the Event of Nuclear Accident Origination and the System of Information Support to State Control of NPPs and Nuclear Research Installations within Normal Operation and Emergencies” that has been approved by Deputy Chairman of Rostechnadzor Alexey V. Ferapontov on January, 25, 2013 will allow to increase the regulatory role of Rostechnadzor.

STC has decided to

1. Take into account the information presented.
2. Perform testing of the proposed methodology of express-evaluation of the release source-term in the event of accidents at VVER-1000 types units (B-320 project) in the framework of emergency exercises at IAC of Rostechnadzor (responsible for: Nuclear and Radiation Safety Division; deadline December 31, 2015).
3. Following the results of testing to finalize the draft methodological document “Methodology of express-evaluation of release source-term in case of accidents at VVER-1000 types units (B-320 project)” and submit it for approval within the established procedure (responsible for : Nuclear and Radiation Safety Division; deadline: February 01, 2016).

On the second issue

Having heard the presentation made by postgraduate student G.R. Pipchenko,

STC has noted that

Postgraduate student of the year 2014 G.R. Pipchenko has presented Individual Plan for education within the period of 2015. This plan has been was prepared in the correspondence with Basic educational program for post-graduate professional development (with the specialization No.05.14.03 in “Nuclear power installations, including design, operation and decommissioning”) and it covered the chosen direction of scientific work. The Individual Plan included training, research work on dissertation topic and list of publications planned.

In respect to the second issue, STC has decided

1. The Individual Plan of postgraduate student G.R. Pipchenko to be recommended for approval.
2. Scientific tutor Mr. Oleg Yu. Kavun, Ph.D, is recommended to address in detail the following aspects of the dissertation work with G.R. Pipchenko:
   • academic novelty;
   • what is to be considered for the thesis defense;
   • practical relevance.

On the third issue

Upon hearing the report made by Аnatoly А. Afanasiev, Scientific Secretary of SEC NRS,

STC has noted that

1. All recommendations approved by STC in the course of the year 2014 , by the subdivisions of SEC NRS are, in general, fulfilled.

STC has decided to

1. Take into account the information presented by Аnatoly А. Afanasiev, Scientific Secretary of SEC NRS, regarding the implementation of decisions from Scientific and Technical Council of SEC NRS for the year 2014.

Chairman: А.А. Khamaza

Scientific Secretary: А.А. Аfanasiev