mit-crpg / beavrs

A two-cycle full-core PWR depletion benchmark based on a commercial nuclear power plant

BEAVRS

The BEAVRS benchmark (Benchmark for Evaluation And Validation of Reactor Simulations) represents a 4-loop Westinghouse plant with a detailed description of fuel assemblies, burnable absorbers, in-core fission detectors, core loading and re-loading patterns. This benchmark enables analysts to develop extremely detailed reactor core models that can be used for testing and validation of coupled neutron transport, thermal-hydraulics, and fuel isotopic depletion. The benchmark also provides measured reactor data and assocaited uncertainties for Hot Zero Power (HZP) physics tests, boron letdown curves, and three-dimensional in-core flux maps from 58 instrumented assemblies.

This repository contains the latest release of BEAVRS, including:

• documentation: pdf and latex source files for the specifications and UQ report
• measurement data: detector signals, power history, boron letdown, etc
• models: inputs of simulation codes (e.g., OpenMC) for BEAVRS

Reporting

BEAVRS Users Group: https://groups.google.com/forum/#!forum/beavrs-users

beavrs's Issues

specifications of Composition of Borated Water

It seems that the formula page 145, (source 62) :
rho_Bh2o = h2o_dens / wB_Bh2o
is not correct (I use syntax of https://github.com/mit-crpg/BEAVRS/blob/master/models/openmc/beavrs/materials.py).
according to your sources it should be :
rho_Bh2o = h2o_dens/(1 - wB_Bh2o)

burnable poison rods for cycle 2

Some assemblies with burnable poison rods in cycle 1 move to position with control rod for cycle 2 (N03->H02 for example).

I suppose that all burnable poison rods are removed from these assemblies. Is it correct?

Also, are all the burnable poison rods removed for from the non fresh assemblies ?

specifications of bp geometry : coherency between fig 9, 40

In fig 9, external radius is guide tube at dashpot.
In fig 40, external radius is guide tube above dashpot for the zone described in fig 9.

is figure 9 wrong ?

Nozzles and Support Plate approximation

I wonder if the water density is correct in the nozzle (source 63) because it doesn't take into account the volume of the instrument rod for the lower part and the steel rods above the rods in the upper part

also above the burnable absorber rods

I found https://www.nrc.gov/docs/ML0335/ML033530020.pdf for ref 15 used in source 64. Is it correct?
reading Table 2-3 of [15] it seems that region 1 an 6 have steel inside (respectively 0.1770 and 0.1720). Why is there only water in these parts in figs 32-35?

also, lower nozzle seems to be more or less region 5 of Table 2-3 of [15] (according to elevation), for which steel fraction is 0.1439 and not 0.1720. Is 0.1720 really expected in source 64?

sorry for those questions. if they are not appropriate, just let me know.

Thanks for your questions about the compositions/densities in the nozzle/support plate region. The approximations used may be improved by accounting for the volume of the extra rod, differentiating the nozzle and support plate... But I'm not sure how much they are affecting the simulation results. Have you done any testing before?
Anyway, I'll leave this as another issue. Please go ahead if you are interested to make the changes to the openmc model, do some tests, and submit a PR.

Originally posted by @liangjg in #4 (comment)

Material temperatures in openmc model

All temperatures are at 300K when this a HZP benchmark, so temperatures should be at 560 - 566K.

Water density is for 560K. If 300K is what we want, water density should be changed.
Also mats['Water SPN'] does not have a temperature specified.