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From “Shelter” to New Safe Confinement

A. GoraDeputy General Director for Personnel ManagementSSE “Chernobyl NPP“, Ukraine

ChNPP Strategic Planning Service2

CommissioningCommissioning

Development of established ChNPP capacities:September 26, 1977

– Unit 1

was commissioned

December 21, 1978 – Unit 2

was commissioned

December 3,

1981 – Unit 3

was commissioned

December 21, 1983 – Unit 4

was commissioned

Turbine HallSight on turbogenerators

TG-1,2

ChNPP Strategic Planning Service3 3

Accident of April 26, 1986Accident of April 26, 1986

Accident at Chernobyl NPP Unit 4 occurred on April, 26, 1986 at 01:23:40 a.m. (Moscow time)

It was possible to stop active release of radioactive substances from destroyed reactor only in the end of May, 1986

プレゼンター

プレゼンテーションのノート

Accident at Unit 4 of Chernobyl NPP occurred on April, 26, 1986 at 01:23:40 a.m. (Moscow time). This event has occurred during design tests with imitation of the maximum designed accident and loss of external power supplies of the equipment. For the guaranteed cooling of the reactor in such conditions the design stipulated supply of the electric power at the power unit from turbogenerators stopping «on stopway». ChNPP Unit 4, as well as other power units with RBMK, has been commissioned without approbation of this mode, though such tests should be a component of pre-commissioning tests of the main designed modes of the power unit. � Tests at Unit 4 had been carried out at the lowered thermal capacity of the reactor 700 MWt, then it was planned to stop the reactor for planned repair work performance. Characteristics of such mode have made direct impact on the magnitude of accident.


Accident of April 26, 1986Accident of April 26, 1986

The rate of gamma-radiation dose was up to 2,000 R/h

(20 Sv/h) and

mainly was determined by radiation from reactor breakdown itself, inside of which measurable values of dose rate amounted to 50,000 R/h

(500 Sv/h).

プレゼンター


Already first measurements of dose rate around destroyed unit and within whole ChNPP site amazed by the values. Near the unit, dose rate of gamma-radiation was up to 2,000 R/h (20 Sv/h) and mainly was determined by radiation from reactor breakdown itself, inside of which measurable values of dose rate amounted to 50,000 R/h (500 Sv/h). In the middle of May 1986, the Governmental Commission took a decision on long-term preservation of destroyed Unit 4. Implementation of this task was complicated by extremely high gamma-radiation doses, absence of reliable information about destruction level and structure condition of Unit 4, lack of world experience in eliminating such accidents.


Creation of Shelter ObjectCreation of Shelter Object

•

Designing of protective sarcophagus (Shelter) commenced on May 20,

1986;•

Construction lasted 206 days and nights from June to November 1986.

プレゼンター


The designing of protective sarcophagus (Shelter) was started on May 20, 1986. Construction lasted 206 days and nights from June to November 1986. About 90 thousand people (builders solely) participated directly in it. On November 30, 1986, the Act of Governmental Commission on accepting preserved Unit 4 of Chernobyl NPP for maintenance was signed, and approximate period of structures operation was defined as 30-40 years. Thus, the first (heroic) stage of ChNPP accident elimination was completed. Unprecedented in its scope man-caused source of danger was localized.


New Safe Confinement Creation (NSC)New Safe Confinement Creation (NSC)

In 2012

it is planned to start production of steel constructions of NSC Arch.

Milestones for NSC creation:•

Foundations construction completion

–

May,

2013.

•

Main Arch construction assembly

–

November, 2014.•

NSC Commissioning

–

October,

2015.

プレゼンター


The beginning of next stage of implementing Shelter transformation strategy was the activity on constructing new protective cover in a form of Arch or New Safe Confinement (NSC) over Shelter Object, being one of the most important conditions for Shelter transformation into ecologically safe system. NSC will be equipped with load-lifting mechanisms (cranes) system enabling in the future to dismantle Shelter structures and get the access to fuel-containing masses for subsequent management of them. Shelter Implementation Plan (SIP) and Strategy of SO transformation into ecologically safe system are developed and are under implementation. In 2012 it is planned to start production of steel constructions of New Safe Confinement Arch. Terms of New Safe Confinement commissioning is October, 2015.


ChNPP Units shutdownChNPP Units shutdown

Chernobyl NPP Unit 3 was finally shutdown on December 15, 2000 at 13:17 according to the Decree of the President of Ukraine. Plant stopped power generation.

プレゼンター


Ukraine, showing good will and carrying out the international obligations, on December 15, 2000 has finally shutdown last operational Unit of Chernobyl NPP, before exhaustion of a designed life-time. Chernobyl NPP Units 1, 2 and 3 were shutdown 30.11.96, 11.10.91 and 15.12.2000 correspondingly, at the moment they are in shutdown stage.


Before the accident Chernobyl NPP generated 150.2 billion kW/h . After the accident – 158.6 billion kW/h. In total it was generated 308.8 billion kW/h.

Unit 1Unit 2Unit 3Shelter Object

1977÷19961978÷19911981÷20001983÷1986

Chernobyl NPP site from satellite

ChNPP Units shutdownChNPP Units shutdown


STRESS-TESTSTRESS-TEST

In 2011 the Chernobyl NPP, the first among Ukrainian NPPs, performed the targeted unscheduled safety assessment of ChNPP nuclear facilities by its own forces taking into consideration the events at Fukushima 1 NPP (stress-test).

The full-scale emergency trainings including personnel actions in case of accident and examination of the capabilities of emergency response units

were conducted.

Safety Improvement Plan for ChNPP facilities was developed:•

control, collection and return system for ISF-1 leakages was created;

•

conditions enabling to connect a mobile diesel generator for ISF-1 consumers were created, tests were carried out;

•

it is planned to conduct psychological training of personnel aimed at increasing resistance to psychological stress, development of endurance, self-control, mutual supportiveness and interaction;

•

system of psychological selection and training of persons involved in managing the accidents with severe consequences is being developed (similar to system of operational personnel selection).

プレゼンター


In 2011 the Chernobyl NPP, the first among Ukrainian NPPs, performed the targeted unscheduled safety assessment of ChNPP nuclear facilities by its own forces taking into consideration the events at Fukushima 1 NPP (stress-test). Under the results of the assessment: A new Plan for ISF-1 safety improvement taking into consideration the creation of conditions for safe storage of all undamaged SNF was developed. Several measures on reconstruction of energy supply, fire protection, control and nuclear safety assurance systems were implemented.


Spent Nuclear Fuel Management (SNF)Spent Nuclear Fuel Management (SNF)

At the moment reactors of Units 1, 2 and 3 are completely released from nuclear fuel.Fuel is only in cooling pools of Units 1 and 2.To reduce risks during New Safe Confinement construction, spent nuclear fuel was transferred from cooling pools of Unit 3 to Interim Spent Fuel Storage Facility (ISF-1).In order to improve nuclear safety, it was proposed to transport SNF from Units 1 and 2 to ISF-1 for storage. In November 2011, the State Nuclear Regulatory Inspectorate of Ukraine agreed the Decision to place all conditioned SNF from Units 1, 2 and 3 to ISF-1.Works on spent nuclear fuel transportation from cooling pools of Units 1 and 2 to ISF-1 were commenced.

プレゼンター


At the moment reactors of Units 1, 2 and 3 are completely released from nuclear fuel. Fuel is in cooling pools of Units 1 and 2. To reduce risks during New Safe Confinement construction, spent nuclear fuel was transferred from cooling pools of Unit 3 to Interim Spent Fuel Storage Facility (ISF-1). In order to improve nuclear safety it was proposed to transport SNF from Units 1 and 2 to ISF-1 for storage. In November 2011, a decision to place all conditioned SNF from Units 1, 2 and 3 to ISF-1 was agreed. It is planned to start the activities on SNF transportation from Units 1 and 2 to ISF-1 in December 2011.


The Final State of Decommissioning NPP can be changed

The Final State of Decommissioning NPP can be changed

"Green field" status

"Brown spot" status

Developed industrial site

ChNPP is located at the territory of Exclusion Zone contaminated with radioactive substances as a result of accident in 1986. That’s why decommissioning of Chernobyl NPP up to the "green field" status is unreasonable.

A brown spot is a condition of ChNPP industrial site when its territory and buildings can be restricted released from the regulating control.

Reuse of ChNPP site as “National operator of NPP units decommissioning, SNF and RAW management”

is the most desirable final state:

•

a fast and cheap way to reach decommissioning objectives

•

using financial and technical resources and qualified staff of ChNPP more effectively;

•

solving problems of nuclear industry.

プレゼンター


Fifteen years ago green field was the final status of Decommissioning ChNPP. Very soon it became obvious that it was unreasonable to obtain green spot in the contaminated Exclusion Zone. In such a way “brawn spot” status appeared. But now reuse of the site is being considered. The most desirable final state is a developed industrial site - a national operator of NPP decommissioning, SNF and RAW management. The site reuse enables: to reach decommissioning objectives in a fast and cheap way to use financial and technical resources and qualified staff of ChNPP more effectively to solve problems of nuclear industry moreover it will solve social problems in the region. We input our efforts in this direction. Now our Parliament is passing the law concerning management of spent nuclear fuel. According to it, the Centralized storage of spent nuclear fuel from all Ukrainian NPPs will be the part of ChNPP’s complex of SNF management. Because of ChNPP location at the territory of Exclusion Zone contaminated with radioactive substances as a result of accident in 1986, and Unit 3 has the common building constructions with the "Shelter" object, and taking into account absence of prospects of new power or other economic facilities construction at the site, to decommission Chernobyl NPP up to the "green field" status (unrestricted release from the regulating control) is inexpedient. Proceeding from that, the most acceptable final objective of ChNPP decommissioning is achievement of a condition, which can be conditionally determined as "brown spot". A brown spot is a condition of ChNPP industrial site at which technological systems and equipment and some auxiliary buildings and constructions are dismantled and activity of main building constructions and remaining buildings as sources of ionizing radiation is reduced up to the levels of the restricted release from the regulating control. It is economically inexpedient to perform complete dismantling of building constructions of ChNPP industrial site within the framework of the Decommissioning Program because of its location in 10-km Exclusion Zone most contaminated with long-lived radionuclides and presence of large quantity of other buildings and constructions at the Exclusion Zone territory (for example Pripyat town). Such task should be solved within the framework of entire Exclusion Zone remediation. Only auxiliary buildings and constructions not used for decommissioning needs and representing hazard to people working at the site owing to their probable collapse because of building construction deterioration are subject to dismantling within the framework of Chernobyl NPP Decommissioning Program.


SSE ChNPP Emergency Preparedness System

SSE ChNPP Emergency Preparedness SSE ChNPP Emergency Preparedness SystemSystem

The Main Tasks of ChNPP Emergency Preparedness and Response System

•

Assurance of preparedness to eliminate accidents and emergencies at SSE “Chernobyl NPP”

facilities;

•

Response to accidents and emergencies at the SSE “Chernobyl NPP”

facilities;

•

Implementation of measures on protecting the NPP personnel and environment.


SSE ChNPP Emergency Preparedness System

SSE ChNPP Emergency Preparedness SSE ChNPP Emergency Preparedness SystemSystem

Emergency organizational structures of SSE “Chernobyl NPP” includes:

Emergency Manager at industrial sites of SSE “Chernobyl NPP”

facilities (EMS);

Coordination and Management Body –

EMS Staff Office or SSE “Chernobyl NPP”

Commission on the Issues of Emergencies (as a synonym);

Standing Management Body –

Emergency Preparedness and Response Department (EP&RD);

SSE “Chernobyl NPP”

emergency teams and units:

Radiation control unit;

Dosimetric survey unit;

Physical protection assurance unit;

Personnel sanitary treatment unit;

Transport unit, etc.;

Teams for elimination of equipment failures.


SSE ChNPP Emergency UnitsSSE ChNPP Emergency UnitsSSE ChNPP Emergency Units

The Main Tasks of NPP Emergency Units are:

Actions on preventing beyond-design-basis accidents and eliminating their consequences;

Measures on personnel protection;

Recommendations on population protection.

A General Director is an Emergency Manager at the ChNPP industrial site.


SSE ChNPP Emergency UnitsSSE ChNPP Emergency UnitsSSE ChNPP Emergency Units

The Main Functions of EMS:

Primary and subsequent classification of an accident;

Notification of personnel and external organizations;

Initiation of Emergency Plan;

Management of actions on accident containment and elimination;

Coordination of actions of external organizations involved into emergency and rescue operations;

Provision of information to a Ministry of Emergencies management, regulatory body, authorities and mass media;

Decision-making on Emergency Plan’s ending.

The SSE ChNPP personnel is contained in protective shelters having ץ-radiation dose rate ≥ 0,5 mSv/h.The SSE ChNPP personnel is evacuated having ץ-radiation dose rate ≥ 1 mSv/h.


Thank you for attention!

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