PWR differences.

[Higgs]

Friends,

I am licensing on a Westinghouse 3 looper..., can anyone tell me what the major differences are between a Westinghouse PWR and a CE PWR?

Thanks

Justin

PS CM you don't know, so don't reply.

[Fermi2]

Two pumps per loop. 2 Loops. A few different RPS parameters mostly due to OTDT and OPDT.

[Higgs]

A lot less than I thought! Thanks BZ!

Justin

[Pman52]

A few different RPS parameters mostly due to OTDT and OPDT.

Can you please explain this a little more?  What does OTDT and OPDT stand for?  Thanks!

EDIT: Just did a quick search and found Over Temperature Delta Temperature (OTDT) and Over Power Delta Temperature (OPDT).  This was referring to trip functions.

But I guess I still would like to know more if you wouldn't mind explaining...

[Fermi2]

They are sliding RPS set points based on not exceeding certain limits. By Sliding I mean the lower the power the higher the set point. OTDT (Over Temperature Delta Temperature) means for a certain power based on Delta T across the core you can only have a certain temperature for a certain pressure. Power based on Delta T, RCS Pressure, Tave, and Delta Flux (The difference between power in the top and bottom of the core) are all mixed into an equation, if these parameters are outside a certain band for a given Delta T they generate a setpoint change. At 100% power the Setpoint is about 115% or so.  This doesn't necessarily mean 115% power it's simply a setpoint. It's designed to prevent core boiling. One common question we like to ask PWR Operators is if you have a rapidly lowering Pressurizer Pressure what causes the reactor to scram? Most say Low Pzr Pressure. In fact in most cases OTDT will get you first because lowering pressure rapidly changes the setpoint downward.

OPDT is OverPower Delta Temperature. It looks at the same stuff as OTDT with the exception of Pressure. It's not so much a thermal limit to protect from core boiling. It's there to protect the fuel from melting. At 100% its setpoint is about 108.7%

Delta T is used as it's the best quickest way to get power in the core.

It's pretty cool watching the meters move as we maneuver the plant around.

IIRC in a CE plant they use a Core Protection Calculator which I believe calculates similar setpoints.

CE EOPs are nearly identical to Westinghouse EOPs though the rules of usage are a bit different.

They have identical Rod Control Systems and the NRC considers them to be nearly equivalent plants.

[Higgs]

Ah good to know! And, I am at the point in my license class that I totally understood what you posted about OP/OTDT.

[HydroDave63]

PS CM you don't know, so don't reply.

Sure I do.

10 letters.

Nope, 12 letters...

[RDTroja]

westinghouse = 12 letters
CE = 2 letters

net difference of 2 letters. 

Remedial Math classes available cheap. IM for details.

[Higgs]

In all fairness, Combustion Engineering doesn't exist anymore with the nuclear portion being owned by Westinghouse..., so one could argue there is no difference.

[MacGyver]

OMG one little typo.......... :p


friggin nukes...

edit: 10 letters. TEN rawr.

rawr?

or rawr?

or rawr?

or rawr?

Charlie Tuna you're so smooth ....