development of sc to support decision making for waste retrieval from historical radon-type...

Development of SC to support Decision Making for Waste

Retrieval from Historical RADON-type Facilities

Alexander Smetnik, FSUE VO “Safety”

IAEA Headquarters, Vienna, Austria28 September – 2 October 2015

Technical Meeting of the International Project on Demonstration of the Operational and Long-Term Safety of Predisposal Management Facilities for Radioactive Waste

(CRAFT Part II)

RADON facilities

• The system of RADON facilities was established the USSR in early sixties of the XXth century collection, transportation, processing and

disposal of LILW wastes and disused sealed radioactive sources (DSRS), generated or used in medicine, research institutions, various branches of industry

35 “Radon” facilities in the Soviet Union 16 of them in the Russian Federation

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RADON facilities

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1 - Moscow «Radon» Facility2 - Leningrad «Radon» Facility3 - Volgograd «Radon» Facility4 - Nizhny Novgorod «Radon» Facility5 - Grozny «Radon» Facility6 - Irkutsk «Radon» Facility7 - Kazan «Radon» Facility8 - Samara «Radon» Facility9 - Murmansk «Radon» Facility

10 - Novosibirsk «Radon» Facility 11 - Rostov «Radon» Facility 12 - Saratov «Radon» Facility13 - Sverdlovsk «Radon» Facility14 - Bashkirskiy «Radon» Facility15 - Chelyabinsk «Radon» Facility16 - Khabarovsk «Radon» Facility

RADON facilities

• Typical historical repositories are vaults below the ground level with the volume from 200 to 9000 m3,

• basement made of concrete plates,• walls made of monolithic reinforced

concrete or concrete blocks,• divided with concrete or wooden walls into

cells (sections),• the top is covered with reinforced concrete

plates, sand and waterproof asphalt layer

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RADON facilities

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depth – 3-6 m width – 5,5 up to 32 m length – 16 up to 100 m.

Radon facilities

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Designed and operated as disposal facilities for institutional LILW without intention of the waste retrieval

Don’t fit with the safety requirement for near surface disposal (long lived alpha emitters, high active DSRS etc.)

Don’t fit with the safety requirements for long term storage (waste package inspection, retrievability etc.)

Radon facilities

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Operators of RADON type facilities are obliged to perform safety assessment and upgrade safety

Decision making depends not only from the safety issues but from socio-political, technical and economic aspects

Most common decisions include: decommissioning of facility upgraded storage facility upgraded disposal facility

Measures are often considered: partial or complete RW retrieval and

conditioning reconstruction

Objectives of the RADON-Type Facilities Working Group

(CRAFT)

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to adopt the safety assessment methodology presented in the GSG-3 for the RADON type facility needs;

to develop illustrative test case for applying this methodology to RADON type facility using SAFRAN tool;

to provide Member States with the supporting information for decision making regarding the future of existing historical RADON type facilities.

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Legal & Regulatory Framework -Regulation of RAW Management in Russia

Predisposal RAW management. General Safety Requirements

GSR, part 5

Predisposal RAW management. General Safety Requirements

GSR, part 5

Disposal of radioactive wastes. Principles, criteria and general safety requirements.

NP-055-04

Disposal of radioactive wastes. Principles, criteria and general safety requirements.

NP-055-04

Near-surface disposal of radioactive waste. Safety requirements.

NP-069-06

Near-surface disposal of radioactive waste. Safety requirements.

NP-069-06

Collection, treatment,

storage and conditioning of

solid RAW. Safety

Requirements. NP-020-2000



solid RAW. Safety




liquid RAW. Safety




liquid RAW. Safety


Gaseous RAW management.

Safety Requirements.

NP-021-2000

Gaseous RAW management.

Safety Requirements.

NP-021-2000

Disposal of Radioactive Waste. Special Safety Requirement

SSR-5

Disposal of Radioactive Waste. Special Safety Requirement

SSR-5

Near-surface disposal. Safety Requirements

WS-R-1

Near-surface disposal. Safety Requirements

WS-R-1

Safety FundamentalsSF-1

Safety FundamentalsSF-1

Safety of Radioactive Waste Management. General Provisions

NP-058-04

Safety of Radioactive Waste Management. General Provisions

NP-058-04

RAW WAC for DisposalNP-ХХ-ХХХ

RAW WAC for DisposalNP-ХХ-ХХХ

Decree №1069: Criteria for classifying radioactive waste to special and retrievable RAW

Special RAW

• The collective effective dose for the entire period of the potential danger• The risk of potential exposure

Retrievable RAW

RAW generated:• in result of implementation of the state program of armaments and state defense

order• In result of the use of nuclear weapon for peaceful purposes• In result of nuclear and (or) radiation accident in nuclear facility• liquid RAW, accumulated in surface water-storage facilities, totaling more than

25000 m3, commissioned before the entry into force of the Federal Law "On the treatment of waste ...", as well as the sediments of the storage reservoirs meet the following criteria:

• The cost of moving away, processing, conditioning, transportation to disposal facility and disposal of radioactive waste

Moving awayOn site disposal

• The size of the possible harm to the environment• The cost of disposal of radioactive waste, including

conversion Site of sRAW to RAW disposal facility, its operation and closing, its safety over the period of the potential danger

RAW storage and its sanitary protection zone located outside the boundaries of settlements, protected areas, coastal protection strips and water protection zones of water bodies, and other security protection zones

1

2

3

Other RAW that hasn't been assigned to special RAW

>

> On

sit

e di

spos

al

Mov

ing

away

Legal & Regulatory Framework

Context of the safety case

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GSR Part 5. Predisposal management of radioactive waste. — Vienna: International Atomic Energy Agency, 2009.

Requirement 13: Preparation of the safety case and supporting safety assessment

The safety case has to be prepared by the operator early in the development of a facility as a basis for the process of regulatory decision making and approval.


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No. GSG-3. The safety case and safety assessment for the predisposal management of radioactive waste: General safety guide. — Vienna: International Atomic Energy Agency, 2013.

The safety case provides the basis for safety decisions with respect to siting and location, design, construction, operation and decommissioning of a facility, including for the justification of changes with a significant impact on safety.


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The safety case was developed as the project progress and can be used as a basis for decision making relating to selection of the decommissioning option

The purpose of safety assessment performed as the illustrative test case is to test initial ideas of the waste retrieval and improvement of technological rules for waste retrieval procedure and/or decision making related to the decommissioning options for historical Radon-type facility


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The assessment of the future management of retrieved waste is not part of the current safety assessment and safety case. This can be covered by other relevant safety assessments addressing the management steps for such waste, i.e. its clearance, discharge, processing, storage, transport and disposal


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The endpoint of the safety assessment was the doses for the workers as result of external irradiation and inhalation both for normal and accident scenarios. For treating uncertainties in the safety assessment, cautious assumptions was used, but, in view of the intervention situation, these should be as realistic as possible


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Timeframe for safety assessment for dose calculation is the sum of time required for all considered technological operations. In terms of possible accidents caused by external events the timeframe cover all the period of waste retrieval operations at the site.

Safety assessment calculations were performed using SAFRAN and other tools.

Description of the facilities, activities and the waste

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Murmansk solid radioactive waste storage facility is the typical near surface vault constructed from reinforced concrete below the ground level and divided into four cells of 200 m3 each.


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21


22

Lake


23View of the four RW storage vaults


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Waste is not conditioned and in some cases is packed


Legend Waste Number.Б1 – Б10 Cylindrical metal containers 10К1 – К10 Rectangular metal containers 10ЯБ1 – ЯБ6 Concreted and partially damaged wooden boxes 6Ф Box with air filters 1Balls Blocks of gamma-ray sources ~ 40- Unidentified objects 6

Vault No1

There are DSRSs in transport containers, few wooden boxes with unknown cemented waste, packages with ion-exchange resins and others.

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Rectangular metal containers Concreted and partially damaged wooden boxes

Blocks of gamma-ray sources BGI-75 Blocks of gamma-ray sources E-1M26


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The inventory consists mostly from 226Ra, 152Eu, 137Cs, 60Co and 3H and other radionuclides.

The nearest settlement is in the distances of about 10 km from the facility.


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Construction of temporary protecting building

RADON

Murmansk

Gates

Walls

Storage vaults

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Ground water close location is one of the main reason of RW retrieval from

RADON facilities

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The host rocks of Murmansk RF contain groundwater, the level of which varies throughout the year from 2 m to 5 m from the surface.

Retrieval activities

1

3

2

4

5

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The waste retrieval scheme

Containers, boxes

Radiation control and monitoring

Check of holding devices of packages

Sling and

control lifting

Moving of

packages

Placing into

transport container

Top cord uncouplin

g

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The radiation survey results

ObjectPosition

centre N S W EБ1 15 50 7 30 20Б2 200 120 70 160 150Б3 70 1000 120 56 18Б4 500 600 1000 2000 2000Б5 40 8 600 50 21Б6 19 2 10 12 13Б7 60 50 24 50 50

Dose rate, µSv/h

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Dose criteria for safety

assessment

PersonsIndividual year dose,

mSv Note

Normative

limit

Controllimit

Personnel 20 10 2-multiple reserve

Population 1 0,1 Approved quota

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Stages and operations of waste retrievalStages

Number of operations

№ Name

1 Retrieval of liquid waste

2 Retrieval of containers and packages

~35

3 Retrieval of gamma radiation blocks

40

4 Spillage gathering 20

5 Vault decontamination№ Slinger Crane operator Dosimetrist

1 Go down into vault Waiting of commands Examination of working place

2 Package Sling Hook descent Waste package examination

3 Raise out of vault Raising package on 100 mm

4 Top cord uncoupling Raising package on level of the canyon overlapping

5 Secondary sling Displacement into container

Operations of stage №2

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SAFRAN tool

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The SAFRAN (Safety Assessment Framework) is a user-friendly software application that incorporates the methodologies developed within the IAEA SADRWMS and CRAFT projects.

http://www.safran.facilia.se/safran/show/HomePage



SAFRAN tool structure blocks

Personnel

Phase

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SAFRAN model detailing

38Areas of work and retrieval activities


39Waste retrieval activities for the personnel


40Initiating events for accidental scenarios


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Consequences of the considered events can be generalized as:- Drop of waste package;- Loss of power supply.Workers and members of population are collectively addressed as endpoints for the considered accidental events.At the first accidental scenario it is assumed, that accident leads to loss of tightness of waste packages, ingress of Cesium-137 and Strontium-90 radionuclides into the air of the room and their escape outside (taking into account the filtration efficiency of 0.9).


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Under the second accidental scenario the consequences of ventilation malfunction are considered, due to which the room starts accumulating Radon-222, and occupational personnel exposure increases due to the inhalation component. In case of unavailability of the forced ventilation under permanent ingress of Radon-222 into the room, its concentration value should be controlled by two processes:- air outlet from the room due to natural convection;- radioactive decay (half-life period 3.823 days).

Calculated exposure dose rates

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Conclusions• In summary, based on the available evidence and safety analysis, the conclusion of this safety case is that the waste retrieval operations can be safely undertaken and provide a solution to the hazards currently posed by the interim storage of waste at the Murmansk RADON facility.

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Conclusions

• Comparison with safety criteria: The results of the quantitative safety assessment as reflected above are well within the national and international safety criteria for workers and the public. The anticipated dose for workers is 2.9 mSv in comparison to the dose constraint of 10 mSv/annum. The anticipated dose for public is 0.005 mSv in comparison to the dose constraint of 0.1 mSv/annum.

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Conclusions

• Application of SAFRAN tool allows processing of the input data, creation of the demonstrative safety assessment structure and analysis of the alternative options for personnel response actions, occurring in the course of implementation of the concerned activity – under normal operation mode, abnormal operation mode and accidents.

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Thank you!

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FSUE VO “SAFETY”

development of sc to support decision making for waste retrieval from historical radon-type...

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