Radiochemistry of nuclear power plants

[jakeXT]

I knew about eloctrolysis and asked myself where the hydrogen in the recent power plant explosions came from. Looks like it's called Radiolysis...

http://en.wikipedia.org/wiki/Radiolysis

It has now been determined that the explosion at the Fukushima Dai-ichi nuclear power plant some 150 kilometers north of Tokyo was actually caused by efforts to avert a meltdown, technicians having taken a calculated risk with a decision to vent radioactive steam from the severely overheated reactor Number 1. The release set off a hydrogen explosion which partially destroyed the outer turbine building. This did relieve some of the pressure that has been building up in the reactor containment core since off-site power was lost due to the earthquake, halting the flow of coolant water. But the reactor has not yet been brought under control. Four workers were injured in the explosion, and three were later hospitalized for ­radiation exposure.
http://www.ww4report.com/node/9631

I also found this book (Open Book)

Radiochemistry in Nuclear Power Reactors (1996)


6.
RADIATION CHEMISTRY IN REACTOR COOLANT
6.1 INTRODUCTION


The radiation energy generated in the reactor core and absorbed in the coolant is mainly attributed to fast neutrons and gamma rays. Absorption of energy in the coolant results in water radiolysis, which occurs in both BWR and PWR. However, because of hydrogen gas over-pressure in the PWR system, there is no net water decomposition nor oxygen gas production in the PWR system (Section 6.4). The addition of hydrogen in the BWR coolant has become an important technique to reduce the dissolved oxygen level in the coolant and minimize the susceptibility of intergranular stress corrosion cracking (IGSCC) of stainless steel in the BWR primary system.

Because of its reducing nature in the PWR coolant, practically all radioactive and non-radioactive impurities in the coolant are in the reduced chemical forms. On the other hand, the BWR coolant under normal operating conditions is under oxidizing condition and the chemistry of the BWR coolant system is rather complicated due to many oxidizing species (both radicals and stable species). An attempt will be made to describe this complicated system in a limited scope.
http://www.nap.edu/openbook.php?record_id=9263&page=125

[WheelWalker]

1. I think we're all learning a whole lot more than we ever thought we would

about some things we never ever wanted to even consider.

EDIT FOR SYNTAX

[Igel]

2. Hard to tell where the H2 came from.

Radiolysis, possibly; but the chemistry would seem to say that most of the H2 produced radiolytically is going to recombine and yield water. There may be a slight net gain.

On the other hand it also says that they introduce additional H2 in order to stress the system and reduce the amount of O2. LeChatelier would be proud.

In either case, there's going to be H2 in the water; when it's released as steam, there'll be H2 there.

Boom.