ML20043A908
| ML20043A908 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 05/25/1988 |
| From: | Adamson R, Kessler L, Martin G GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20043A901 | List: |
| References | |
| NUDOCS 9005230269 | |
| Download: ML20043A908 (3) | |
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SELLER AL $ ELECTRIC IHT TRANSMITTAL No. 88+212 0019 NUCLEAR FUEL & ENGINEERING SERVICtB DEPARTtdlENT PLfEL MATERIALS TECHN01hGY TEST REPORT DETERMINATION OF FAST NEUTRON FLUX DENSITY AND TLUENCE:
RIVER BEND STATION May 25, 1988 WA LDZ502932 DRF AOO.02764 J/h/
Prepared By:
. C. MvD
~Date-G. C. Martin Fuel Materials Technology Reviewed By:
a /M
(/////
L.' K. Kessler
'Date Fuel Materials Technology F
N Reviewed By:
R. B. Adamson, Manager Date Puel Materials Tochnology I
9005230269 900514 f
{DR ADOCK 05000458 i
PDC W
f FMT 88 212 0019 DETERMINATION OF FAST NEUTRO,N FLUX DENSITY AND FLUENCE!
RIVER BEND STATION SlMMARY The fast neutron flux density and fluence (integrated neutron flux) at a capsule near the reactor vessel wall of the Rivet Bend Station of Culf States Utilities have been determined to be:
4.4x10' necm.8.s.1
>l MeV full power flux density 7.1x10' necm.8.s.2
>0.1 MeV full power flux density 1.4x1017 necm.2
>l MeV fluence 2.2x1017 n'en 8
>0.1 MeV fluence following the analysis of irradiated iron flux dosimeters, in accordance with the GE CM&S Method No. 10.1.6.0 R3.
EXPERIMENTAL Three iron wires were irradiated in a CE pressure vessel capsule holder at River Bend Station from October 30, 1985 (startup) to September 14, 1987 (end of cycle 1).
Each wire was removed from the capsule, cleaned with 4N MN0s weighed, mounted on a counting card, and analyzed for Mn 54 content by gamma.
spectrometry at a calibrated 4 cm source.to detector distance with 100 ce and 80 ce Ge(Li) detector systems.
I 6
From daily thermal power generation summary tables, three irradiation time periods for Cycle 1 were calculated. Operating days for each period and.the reactor average power fraction are shown in Table 1.
Zero power days between i
periods are also listed.
TABLE 1.
River Bend Station Irradia~ tion Periods Full Power Between Perio3 Period Date Daya Fraction
- Time (Days) 1 10/30/85 10/04/86 340 0.356 i
56 2
11/30/86 - 06/18/87.
201 0.881 10 3
06/29/87 09/14/87 78 0.840
- Full power was 2894 MW.
619 (total) 0.588 (Av)
DISCUSSION OF RESULTS i
From the activity measurements and power history, a reaction rate for s*Fe(n.p)54Mn was calculated. These data appear in Table 2.
The River Bend 1
l 1
m IMT 88 212 0019 Station >l MeV flux density reaction cross section for iron was calcult.ted to be 0.142 barns.
This value was obtained from measured cross section data functions from more than 65 spectral determinations for Bk'Rs and for the GE Test Reactor using activation monitors and spectral unfolding techniques.
These data functions were applied to Bk'R pressure vessel locations based on water gap (fuel to pressure vessel) distances. The >l MeV/ >0.1 MeV cross section ratio at Bk'R pressure vessel locations is approximately 1.6.
The determined full power flux density and actual fluence results at the reactor vessel wall capsule holder location are given in Table 2.
The >l MeV and >0.1 MeV values of 4.4x10' and 7.1x10' n cm 8.s 8 were calculated by dividing the reaction rate measurement data by 0.142 barns and 0.0888 barns, respectively. The corresponding fluence results, 1.4x101? and 2.tx1027 n.cm.2 were obtained by multiplying the full power flux density by the product of the total seconds irradiated (5.348x10's) and the full power fraction (0.588).
The 2a errors of the values in Table 2 are estimated to be:
1 56 for dps/g
[
for dps/ nucleus (sat'd)
)
for ( and dt >1 MeV g
for & and 4t >0.1 MeV The higher than usual uncertainties r}uoted in this report are based on past flux results from several 1 cycle versus 10 year pressure vessel irradiations.
Localized, rather than reactor, power histories should be used when they are different, as has generally been the case during a reactor's initial cycle. i