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Winfrith Water/Iron Benchmark Experiment (ASPIS-PCA REPLICA)

1. Name of Experiment:
 Winfrith Water/Iron Benchmark Experiment (PCA Replica)

2. Purpose and Phenomena Tested:
Determination of neutron spectra and detector reaction rates at different depth in the ASPIS facility in a water/iron shield reproducing the ex-core radial geometry of a Pressurized Water Reactor (PWR).
A replica of the Oak Ridge PCA experiment with a highly enriched fission plate in place of the core source. The cross-sectional area of the fission plate was identical to that of the PCA source.

3. Description of the Source and Experimental Configuration:
The PCA-REPLICA duplicated precisely the Oak Ridge PCA 12/13 configuration (12 and 13 cm of water respectively between the core and thermal shield and between the thermal shield and the pressure vessel-RPV) with the exception that the reactor source was replaced by a thin fission-plate to provide a well characterized neutron source. The fission-plate was irradiated by the NESTOR reactor at UKAEA-Winfrith (30 kW max. power) through a graphite thermal column of total thickness 43.91 cm, in the ASPIS shielding facility.

 The REPLICA shielding array was arranged in a large steel tank (square section; side 180.0 cm) filled with water and surrounded by a thick concrete shield. After the first water gap (12.1 cm), there was the stainless steel thermal shield (TS) simulator (5.9 cm thick) and the second water gap (12.7 cm). Then the mild steel RPV simulator (thickness T = 22.5 cm) was located and tightly connected with a void box made of a thin layer of aluminium, simulating the cavity  (thickness = 29.58 cm) between the RPV and the biological shield in a real PWR.

4. Measurement System and Uncertainties:
The detectors used were:

 Detector       Diameter     Systematic    Random Error
(mm)       Error (%)     (1 sigma) (%)

 Mn-55(n,gamma)   12.7          1.5

 Rh-103(n,n')      *            3.0          1-4

 In-115(n,n')      *            2.0        0.9-1.5

 S-32(n,p)         *            4.0        1.3-1.9

 U-235(n,f)        *            1             3

 SP-2 counter     40.0 (internal diam.)

 NE213 Spectr.   spherical,vol=3.5 ml
* thin foils, can be neglected in the calculations.

 Hydrogen-filled proportional counters with gas fillings of approximately 0.5, 1.0, 3.0, and 10.0 atmospheres were used in combination to cover the energy range from 50.0 keV to 1.2 MeV. Neutron fluxes between 1.0 and 10.0 MeV were determined with a NE213 organic liquid scintillator.

5. Description of Results and Analysis:

 Threshold detectors were located at 10 different positions: in the water gaps 1.91, 7.41, 12.41, 14.01, 19.91, 25.41, 30.41 cm from the fission plate (Rh measurements only) and at 1/4 and 3/4 thickness of the RPV and in the void box (Rh, In, S).
Spectral measurements were performed at two positions: at 1/4 thickness of the RPV and in the void box.
The spectra were unfolded by the RADAK [6] computer code.
At least 2-D calculational model has been recommended by the authors.
Monte-Carlo code McBEND, TRIPOLI, 2-D discrete ordinates transport code DOT-3.5 and 3-D discrete ordinates transport code TORT-3.2 have been used in refs. [1], [3], [9] and [11].

6. Special Features:


7. Author/Organizer
Experiment and analysis:
J. Butler, M.D. Carter, I.J. Curl, M.R. March, A.K. McCracken, M.F. Murphy,
A. Packwood
AEA Technology
WINFRITH, Dorchester
Dorset DT2 8DH

 Compiler of data for Sinbad:
I. Kodeli
OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France

 Reviewer of compiled data:
M. Pescarini(*), S. Zheng(**)
(*) ENEA, Via Don Fiammelli 2, 40129 Bologna, Italy
(**)CEA-Saclay/DMT/SERMA/LEPP, 91191 Gif-sur-Yvette CEDEX, France

8. Availability:


9. References:

[1] J. Butler, M.D. Carter, I.J. Curl, M.R. March, A.K. McCracken, M.F. Murphy, A. Packwood, The PCA Replica Experiment PART I, Winfrith Measurements and Calculations, AEEW-R 1736 (1984)
[2] J. Butler, The NESTOR Shielding and Dosimetry Improvement Programme NESDIP for PWR Applications, PRPWG/P(82)5, Internal UKAEA Document, (1982)
[3]A) M. Pescarini, DOT 3.5-E (DOT 3.5-E/JEF-1) Analysis of the PCA-Replica (H2O/Fe) Shielding Benchmark for the LWR-PV Damage Prediction, ENEA Technical Report, RT/INN/90/21 (1990)
B) M. Pescarini, ENDF/B VI Iron Validation on the PCA-Replica (H2O/Fe) Shielding Benchmark Experiment, ENEA Technical Report, RT/INN/94/11.
[4] M. Pescarini, PCA Replica Shielding Benchmark: Final Comparison of the Validations of the ENDF/BVI and JEF-2.1 Iron Cross Sections, JEF Working Group Meetings, JEF-DOC-392 (1992)
[5] M.D. Carter, I.J. Curl, P.C. Miller, A. Packwood, Light-Water Reactor Radial Shield Benchmark Studies of the NESTOR Shielding and Dosimetry Improvement Programme (NESDIP), Reactor Dosimetry: Methods, Applications, and Standardization, ASTM STP 1001, Harry Farrar IV and E.P. Lippincott Editors, ASTM, Philadelphia
[6] M.J. Grimstone, The RADAK User's Manual, AEEW-M1455 (1976)
[7] McELROY W. N. (Ed), LWR Pressure Vessel Surveillance Dosimetry Improvement Programs: PCA Experiments and Blind Test,
HEDL-TME 80-87, R5 (NUREG/CR-1861), July 1981
[8] STALLMANN F. W., Reactor Calculation Benchmark PCA Blind Test Results, ORNL/NUREG/TM-428 (NUREG/CR-1872), January 1981
[9] J. C. Nimal, S. H. Zheng, Rapport DMT 94/1616, CEA-Saclay
[10] P. C. Miller, A Review of LWR Pressure Vessel Dosimetry and Associated Shielding Studies, Proceedings, 7th International Conference on Radiation Shielding, Sept. 12-16, 1988, Bournemouth, UK, Vol.1, p.37.
[11] M. Pescarini, R. Orsi, M. Frisoni, PCA-Replica (H2O/Fe) Neutron Shielding Benchmark Experiment – Deterministic Analysis in Cartesian (X,Y,Z) Geometry Using the TORT-3.2 3D Transport Code and the BUGJEFF311.BOLIB, BUGENDF70.BOLIB and BUGLE-96 Cross Section Libraries, ENEA-Bologna Technical Report, UTFISSM-P9H6-009 (2014)

10. Data and Format:

    Filename          Size[bytes] Content
---------------- ----------- -------------
1 repl-abs.htm         11.637  This information file
2 repl-exp.htm         34.855  Description of Experiment
3 tripoli4rep_r.inp    24.573  Input for TRIPOLI4 fast neutron calculations (by C. Jouanne)
4 tripoli4rep_t.inp    27.961  Input for TRIPOLI4 thermal neutron calculations (by C. Jouanne)
5 tripoli3rep.inp      11.232  Input for TRIPOLI3 calculations (by S.H.Zheng)
6 REPL-XZ.INP          29.728  Input data for DOT-3.5 (X,Z) calculations (by M. Pescarini)
7 REPL-YZ.INP          29.318  Input data for DOT-3.5 (Y-Z) calculations (by M. Pescarini)
8 REPL-Z.INP           25.790  Input data for DOT-3.5 Z calculations (by M. Pescarini)
9 REPL-1V.TIF          47.024  Fig. 1: NESTOR Neutron Source Reactor (high quality)
10 REPL-2V.TIF          35.034  Fig. 2: ASPIS Shielding Facility (high quality)
11 REPL-3V.TIF          15.834  Fig. 3: REPLICA Layout of the 12/13 Configuration (high quality)
12 REPL-4V.TIF          18.394  Fig. 4: Detail of the REPLICA Fission-plate (high quality)
13 REPL-5AV.TIF          9.326  Fig. 5a: Co-ordinate System (high quality)
14 REPL-5BV.TIF         80.792  Fig. 5b: Mn Foil Measurements (high quality)
15 REPL-6V.TIF          77.104  Fig. 6: Fuel Tablet Arrangement in a Fission Plate Element (high quality)
16 REPL-1V.gif          26.090  Fig. 1: NESTOR Neutron Source Reactor (preview)
17 REPL-2V.gif          21.736  Fig. 2: ASPIS Shielding Facility (preview)
18 REPL-3V.gif          11.126  Fig. 3: REPLICA Layout of the 12/13 Configuration (preview)
19 REPL-4V.gif          13.751  Fig. 4: Detail of the REPLICA Fission-plate (preview)
20 REPL-5AV.gif          6.860  Fig. 5a: Co-ordinate System (preview)
21 REPL-5BV.gif         15.052  Fig. 5b: Mn Foil Measurements (preview)
22 REPL-6V.gif          14.212  Fig. 6: Fuel Tablet Arrangement in a Fission Plate Element (preview)
23 REP_1.pdf         2.708.595  Reference 
24 REP_3A.pdf        2.665.843  Reference
25 REP_3B.pdf        1.392.429  Reference
26 JEF_392.pdf       1.307.352  Reference
27 REP_9.pdf           659.402  Reference
28 aspis_0.pdf         608.178  Reference
29 radak.pdf          1110.016  Reference
Input data for TORT-3.2 (X,Y,Z) calculations (by M. Pescarini)
31 UTFISSM-P9H6-009_rev0.pdf

 Figures describing the geometry of the experiment are included in TIFF4 image and GIF (preview) format.


    1. Fission Product Activity at Certain Positions in the Fission Plate
2. Axial Variation of the Mean Fission-Rate Profile
3. Source Distribution in the 0.6 cm Thick Fission Plate
4. Cylindrical Representation of Fission-Source
5. Dimensions and Materials in PCA-REPLICA
6. Chemical Analysis of the REPLICA Materials
7. Investigation of the Al Plate Bowing
8. Centreline Activation Measurements:  Rh-103, In-115, S-32
9. Fluxes of NE213 Spectrometer
10,11. Activation Measurements on Horizontal Axis:  Rh-103, S-32
12. Cosine Fits
13. Estimation of NESTOR Background
14. Activation Measurements on Horizontal Axis:  Mn-55

SINBAD Benchmark Generation Date: 1995
SINBAD Benchmark Last Update: 02/2016