Lots of shielding. The trade off of a simple, component wise, system such as the BWR compared to a PWR with more components means that potentially more radiaoactive systems and areas exist with a BWR design as compared to a PWR. You need a lot more shielding with a BWR. Access to more areas require suiting up. With a PWR, water chemistry is super critical. Tube corrosion and eventual leaks in the steam generators require tube plugging or sleeving. Lots of tubes plugged means reduced power output. Some plants have been forced to replace steam generators which is a mammoth project since the plants weren't designed for steam generator replacement.
A BWR doesn't have steam generators but you have to monitor more areas and systems for radioactive leaks. You learn real quick not to wear anything made out of a polyester blend at a BWR site. Just walking across the turbine deck will cause you to pick up enough radioactivity to setoff the portal monitors. It's short half-life stuff which means you have to stand around and look stupid until the stuff decays.
Accessing the condensor bay in a PWR is simple. There's no radioactivity. At a BWR plant, it's a high rad area.
Like I said---I was around the PWR.
MANY thanks for the full explaination.
I remember the chemistry stuff and all the corrosion problems. I still remember the SG replacement project at Indian Point 2.
Even with all the extra tubing--give me less power and a PWR anytime. I like turbines--and being near them.
I wasn't a nuke myself--not even in submarines.
My background was conventional steamplants (civilian)
I always had a lot of fun going to the power stations (nuclear and fossil) with Dad (trained in PWR's---I'm am from a family of nukes.) A few cousins were involved in the construction of Shoreham (BWR!)---then it's dismantlement. Always thought that was a disgrace.
anyway---thanks again!
FAS