17.08.2015   Integral design concepts of advanced water cooled reactors

5. EVALUATION OF THE AMOUNT OF RADWASTE AT THE TIME OF INTEGRAL REACTOR DECOMMISSIONING

Radioactive equipment and structures of AST and VPBER plants can be divided in contaminations groups according to their accumulated activity (m coirespondence with national radiological safety norms, that allows evaluation of mass, volume and methods of handling (Fig-s 7, 8).

The hot equipment and structure mass (in-vessel barrel, guide rubes-connecting device unit, etc.) is -60 t for AST and -90 t for VPBER, the medium equipment mass (reactor vessel, heat exchange equipment, etc.) is -270 t for AST and -1850 t for VPBER, the cold and clean equipment mass (guard vessel, concrete reactor silo structures, etc.) is -1000 t for AST and -3750 t for VPBER.

Liquid radwaste formed during cleaning of the circuit water, the reactor and equipment decontamination (liquid radwaste activity does not exceed 1000 Ci) should be reprocessed — it is evaporated, concentrated and bituminized (AST-500) or cementated (VPBER-600) to confine the activity.

Solid radwaste is also reprocessed it is ground, burnt, pressed and sintered It substantially decreases the total volume of radwaste

Protective

cask

 
image179

Fuel assembly and internals reloading

 

Equi pment parting mani pulator

 

Lifting-and-

 

Cuttei

 
image180

Fia. 6

 

image181image182image183

VPBER-600 MAIN EQUIPMENT MASS AND

RADIOACTIVITY

Equipment

characteristics

Total

radioactivity,

Ci

Mass,

t

Disassembly and transport conditions

Hot, group 3 (in-vessel barrel, guide tube­connecting devices unit, etc.)

~1*107

100

Removed from reactor by standard means used during operation. Transported in protective casks

Medium, group 2 (reactor vessel, steam generator piping, pumps, etc.

170

і

;

l

i

1850

The equipment is dismounted and parted by conventional engineering means under the control of radio­logical safety service. Protective casks are required to transport some equi pment

Cold, group 1 and clean (guard vessel, structures in con­crete silo of reac­tor, etc.

!

і

<4

j

і

і

і

і

і

3750

Dismounted as at general industrial plants and does not require special protective measures. Transported without protective casks, organiza­tional measures are provided

I

Fig. 7

AST-500 MAIN EQUIPMENT MASS AND
RAPT О ACTIVITY

Equipment

characteristics

Total

radioactivity,

Ci

Mass,

t

Disassembly and transport conditions

Hot, group 3 (in-vessel barrel, guide tube­connecting devices unit, etc.)

~1*106

60

Removed from reactor by standard means used during operation. Transported in protective casks

Medium, group 2 (reactor vessel, heat exchanger piping, etc.

80

270

The equipment is dismounted and parted by conventional engineering means under the control of radio­logical safety service. Protective casks are required to transport some equipment

Cold, group 1 and clean (guard vessel, structures in con­crete silo of reac­tor, etc.

1-2

980

!

Dismounted as at general industrial plants and does not require special protective measures. Transported without protective casks, organiza­tional measures are provided

1

I

Fig. S

VPBER-600 AND WER-440 fNPP’ LOVISA ) REAC-
TOR UNIT DECOMMISSIONING CONDITIONS

Parameters

VPBER-600

WER-440 (Atomnaya energiya, v.67, is.2 Aug., 1989)

Power, MW(e)

630

470

Service time, years

60

30

Hold-up time following reactor shutdown, years

1

2

Reactor vessel radioactivity, Ci

50

7000

Total radioactivity, Ci

~105

(without internals)

~1.3*106

(without internals and steel cassette-screens)

Irradiation dose rate in reactor silo, mSv/hr

0.05

130

Radioactive waste amount, t

2200

8460

(for 2 units)

Collective irradiation dose for personnel, man. Sv

2,5

23

(for 2 units)