Fukushima -II

This is my second note in the series of Nuclear Reactors...

As i have promised here i will discuss what went wrong actually there in Fukushima..and by describing that i hope i would able to explain to you what are the hazards that can occur due to a Nuclear reactor.

So let us start this with a piece of news that came from Fukushima( i m taking here somelines from the news that would give us some basic points through which we will able to undestand the whole picture)

" The highest priority was placed on the No. 2 reactor, whose reactor containment vessel is feared to have been damaged in the aftermath of the magnitude-9.0 quake that hit the Tohoku region on March 11."----News 1

"It is feared rising water temperature in the temporary storage pool at the No. 4 reactor will lower the water level in the pool and expose fuel rods, resulting in the leakage of radioactive material into the air."----News 2

"At the No. 3 reactor, on which Tokyo firefighters sprayed water from 2:05 p.m. Saturday until 3:40 a.m. Sunday, pressure within the reactor containment vessel started rising again, forcing TEPCO officials to consider releasing steam in the vessel to lower the pressure, TEPCO said.
Pressure in the containment vessel went up from about 2.8 atmospheres at 1:10 a.m. to 3.4 atmospheres at 4:30 a.m." ----News3

"Water temperatures in storage pools in the Nos. 5 and 6 reactors were 37.1 C and 41.0 C, respectively, as of 7 a.m., and were within or near the target temperature range of 40 C or below, TEPCO officials said.
TEPCO said the number of its workers whose radiation exposure exceeded 100 sieverts increased to seven from six as of 5 a.m. Sunday. The government had raised the upper limit of the radiation exposure for workers at the Fukushima plant from the ordinary 100 sieverts to 250 sieverts as an exceptional measure."-----News4

There are many new things for a Layman out there and evrythings desereve a fair amount of expalantion.....so best method of dicussing anything is asking the question...question,,,question and more questions...so first see the array of all the questions:

from News1:
Question 1: What is a conatinment vessel?
In a layman term a containment vessel is a final barrier to radioactive release.."darr gaye first new se na..."
It is designed, in any emergency, to contain the escape of radiation to a maximum pressure in the range of 60 to 200 psi[citation needed] ( 410 to 1400 kPa). There are lots of things that we can discuss about the containment vessel, you can do the wiki for same..though i wil defintely write my own version...later :)
from News2:
Question 2: Where is this water came from and what is this temporary storage pool?
Spent reactor fuel is extremely radioactive, and its radioactivity also makes it a source of heat. It is needed to be shielded and cooled. This is accomplished by putting the spent fuel in a water storage pool located next to the reactor. Water in the pool conatins large amount of boric acid, which is a heavy absorber of neutrons. Now since there is no means to cooling this water, hence the temperature is rising and the water is evaporated and hence the readiation from this fuel can go to the environment.

Question 3: How the pressure in the containment vessel is increasing?
The pressure inside the containment vessel is increasing due to the increase in temperature. As i have said above it can handle pressure from 60 to 200 psi.

Keep looking in to my notes..there are lots of lots of interesting things..out there..we just need to stop and think...he he he..Feynaman se churaya h yeh dialogue...

Enjoy the exploration...

cyaaa