Q 01/05

On what date did reactor 4 at Chernobyl explode?

A) 1 May 1986

B) 26 April 1986

C) 28 April 1985

D) 6 August 1986

Answer · why

B) 26 April 1986

The explosion came at 1:23 in the morning during a test that was supposed to simulate a blackout.

Q 02/05

Which numbered unit at the Chernobyl plant blew up in 1986?

A) 4

B) 1

C) 2

D) 3

Answer · why

A) 4

Reactor 3, next door, kept running until 15 December 2000, when President Kuchma switched it off in a ceremony.

Q 03/05

Besides Chernobyl, what is the only other accident rated at the maximum level of the International Nuclear Event Scale?

A) Fukushima

B) Three Mile Island

C) Kyshtym

D) Windscale

Answer · why

A) Fukushima

The Japanese accident followed the 2011 earthquake and tsunami; both are Level 7 events.

Q 04/05

What was the reactor crew attempting when the accident happened?

A) A routine refuelling of the core

B) A run at record power output

C) An emergency evacuation drill

D) A test simulating cooling in a blackout

Answer · why

D) A test simulating cooling in a blackout

The idea was to see whether the coasting turbine could power the coolant pumps until the diesel generators kicked in.

Q 05/05

What type of Soviet reactor was used at Chernobyl?

A) VVER

B) CANDU

C) BWR

D) RBMK

Answer · why

D) RBMK

The graphite-moderated, water-cooled design had a positive void coefficient, so steam bubbles increased rather than reduced reactivity.