Федеральное бюджетное учреждение Научно-технический центр по ядерной и радиационной безопасности

Transcription

1 Федеральное бюджетное учреждение Научно-технический центр по ядерной и радиационной безопасности Emergency zones setting in order to control the spread of contamination and for monitoring the contamination levels of vehicles, personnel and territories Albert Shapovalov Vienna, 2013

2 Post-Fukushima issues due to Fukushima accident the process of strengthening and developing of emergency preparedness and response regulations and guides, including those related to postaccident phase, was considerably enhanced by Russian nuclear regulatory body (Rostechnadzor) and its technical support organization SEC NRS; as a part of this process in the year 2013 the safety guide Minimization of crosscontamination of areas, traffic routes and vehicles during post-accident phase (further RB ), have been developed and issued; the RB contains guidelines on post-accident zoning and applicable in case of accident on facilities (including NPPs). This guidelines should be used to control the spread of contamination. 2

3 Division of competence Competence Rostechnadzor Social welfare service Establishment of reference levels or generic intervention levels - + Emergency zoning + - Establishment of OILs - + 3

4 Approaches for planning protective actions Generic criteria for planning protective actions Residual dose concept as recommended by: IAEA General Safety Guide GSG-2 (2011) ICRP Publication 103 (2007) Avertable dose concept partially in accordance with: the IAEA Basic Safety Standards SS-115 (1996). ICRP Publication 63 Principles for intervention for protection of public in a radiological emergency In Russia the concept of avertable dose for urgent protective actions established by NRB-99/2009 (sanitary norms & rules) 4

5 Russian regulatory basis. Intervention levels for urgent protective actions according to NRB-99/2009. Protective measures Intervention level of averted dose, msv Whole body Thyroid А-level B-level А-level B-level Sheltering Stable iodine administration: adults children Evacuation if the avertable dose less than A-level, then no protective actions required; if avertable dose less than B-level and exceeds A-level, then decision are to be made according to optimization principle; in case the avertable dose exceeds B-level, then protective action shall be undertaken under any circumstances. There is no commonly accepted procedures on how to make a decision based on optimisation principle Reference level for post accident phase is 10 msv/2months 5

6 Accident threat categories (as established in regulatory requirements NP (applicable for NPPs) Category А01 characteristic Following consequences are expected: Deterministic effects Transboundary transfer А02 А03 А04 Public exposure that higher than B-level according to NRB-99/2009 Public exposure that higher than A-level according to NRB-99/2009 Public exposure over 5 msv/a 6

7 Russian regulatory basis. Buffer zone concept. Buffer zone off-site area (area around facility fence) beyond which in normal operation conditions, exposure of member of public shall not exceed dose constraint set for this NPP (OSPORB-99/2010, SANPiN ) Inside Buffer zone following are prohibited permanent or temporary dwelling of members of public deployment of childcare facilities deployment of industrial and auxiliary facilities not related to facility Buffer zone concept are used for facility threat category determining 7

8 Facility threat categories classification 1. OSPORB-99/ A guide for establishment of facility threat category MU I category If worst-case accident can lead to exposure that exceeding 1 msv for member of public (beyond the buffer zone) than this facility is I category II category If facility not related to I category and worst-case accident can lead to exposure of personnel that exceeding 5 msv (in area that between buffer zone and facility site boundary) than this facility is II category III category If facility are neither related to I category nor to II category and if there is a possibility of workers exposure that exceeding 5mSv than this facility is III category facility IV category remainder 8

9 IAEA documents used for developing of RB Point 4.91 Preparedness and response for a nuclear or radiological emergency GS-R-2: For the emergency zones, arrangements shall be made for monitoring the contamination levels of vehicles, personnel and goods moving into and out of contaminated areas in order to control the spread of contamination. 9

10 IAEA documents used for developing of RB (contd.) As a basis for defining sizes of zones in RB used recommendations of IAEA EPR series document Method for Developing Arrangements for Response to a Nuclear or Radiological Emergency (EPR Method-2003), concerning predefined emergency zones and radius sizes for threat category I and II facilities. 10

11 IAEA documents used for developing of RB (contd.). Emergency zones and radius sizes for threat category I and II facilities, suggested by EPR Method

12 Scope of RB RB applicable for such facilities of threat category I and II as: NPPs and research reactors; Spent nuclear fuel storage facilities; Spent nuclear fuel reprocessing plants; Radwaste storage facilities. According to guide for establishment of facility threat category MU threat categories I and II defined as: I category If worst-case accident can lead to exposure that exceeding 1 msv for member of public (beyond the buffer zone) than this facility is I category II category If facility not related to I category and worst-case accident can lead to exposure of personnel that exceeding 5 msv (in area that between buffer zone and facility site boundary) than this facility is II category 12

13 Two- and three-zone system In RB is recommended to set two- or three-zone system depending on emergency class or projected doses. Three-zone system in case of accident on NPP are to be set in case if accident classified as A01 according to NP Three-zone system in case of accident on facility different from NPP are to be set in case if accident classified as a category similar to A01 from NP (for these facilities documents other than NP define appropriate threat categories) Three-zone system consists of following zones: nearby zone; intermediate zone; common use zone. 13

14 Two- and three-zone system (contd.) two-zone system are to be set in case if radionuclide release could result in exceeding of generic intervention level (effective dose 50 msv) for evacuation, established in Russian basic safety standard NRB-99/2009 and adopted from ICRP Publication 63 Principles for intervention for protection of public in a radiological emergency; In case of accident on NPP two-zone system are to be set in case if accident classified as A02 A03 according to NP ; Two-zone system in case of accident on facility different from NPP are to be set in case if accident classified as a category similar to A02 A03 from NP (for these facilities documents other than NP define appropriate threat categories) Two-zone system consists of following zones: nearby zone; common use zone. 14

15 Recommended zones radii for various facilities 15

16 Examples of protective actions to be fulfilled upon setting of three-zone system Prevent traffic from nearby zone to intermediate zone Implementation of following measures in nearby zone: Traffic speed should not exceed 30 km/h; Sediments should be washed-off from traffic routes to roadside and immobilized with special reagents Radioactive sediments which are result of washing-off of sediments from transport routes should be relocated far away from routes; Caution signs, which prohibit crossing of roadside and staying on it, should be set along the traffic routes; Those vehicles, used by responders, which couldn t be used anymore due to contamination, should kept in nearby zone and substituted by clear vehicles from outside of nearby zone; Arrange a transfer of personnel between vehicles when entering from nearby zone to intermediate zone and from intermediate zone to nearby zone. 16

17 Thank you for your attention! 17