Use of Reactor Pressure Vessel Surveillance Materials for Extended [PDF]

R. K. Nanstad, ORNL. G. R. Odette, UCSB ... UCSB/ORNL ATR-2 irradiation project and .... capsules for weld and one forgi

0 downloads 4 Views 777KB Size

Recommend Stories


neutron embrittlement of reactor pressure vessel steels
This being human is a guest house. Every morning is a new arrival. A joy, a depression, a meanness,

Thermography Detection on The Fatigue Damage of Reactor Pressure Vessel
How wonderful it is that nobody need wait a single moment before starting to improve the world. Anne

Pressure Vessel
In every community, there is work to be done. In every nation, there are wounds to heal. In every heart,

Accelerated Corrosion Tests of Nuclear Reactor Pressure Vessel Materials in NaCl–H3BO3
Life isn't about getting and having, it's about giving and being. Kevin Kruse

pressure vessel design criteria
The wound is the place where the Light enters you. Rumi

Pressure Vessel - Slug Catcher.cdr
Stop acting so small. You are the universe in ecstatic motion. Rumi

Section 4.5 Reactor Materials
Do not seek to follow in the footsteps of the wise. Seek what they sought. Matsuo Basho

for pressure vessels pressure vessel engineering note per chapter 5031
When you talk, you are only repeating what you already know. But if you listen, you may learn something

detailed cfx-5 study of the coolant mixing within the reactor pressure vessel of a vver-1000 reactor
Learn to light a candle in the darkest moments of someone’s life. Be the light that helps others see; i

Large Pressure Vessel Lifting Analysis
Don't fear change. The surprise is the only way to new discoveries. Be playful! Gordana Biernat

Idea Transcript


USE OF REACTOR PRESSURE VESSEL SURVEILLANCE MATERIALS FOR EXTENDED LIFE EVALUATIONS USING POWER AND TEST REACTOR IRRADIATIONS

W. L. Server, ATI Consulting R. K. Nanstad, ORNL G. R. Odette, UCSB

What to Expect    



Introduction and importance Brief description of U.S. RPV surveillance programs Long term operation programs in the U.S. UCSB/ORNL ATR-2 irradiation project and commercial RPV surveillance materials Summary

Introduction 







RPV is first line of defense against release of radiation during an operating accident in LWRs Fracture toughness of RPV is diminished over time due to neutron radiation embrittlement Current regulations take embrittlement into account for operating life; e.g.., pressurized thermal shock (PTS) for PWRs Extended operating life beyond 60 years requires more irradiation data to assure continued safe operation

Key Issue – High ft Data Gap 





For 80 years of operation (and even in some cases for 60 year life) fluence (ft) in the RPV can reach or exceed 5 x 1019 n/cm2 (E > 1 MeV) Current PTS embrittlement model (EONY) has very little surveillance data for ft > 3 x 1019 n/cm2 More surveillance data will be generated in the future, but concern exists that there may be an acceleration in embrittlement at high ft – longer time exposure at RPV operating flux (f) levels

EONY Model Prediction Error as a Function of ft plus 2 Sigma Bounds

Mixture of Test and Power Reactor Data 



Data shown was a mixture of test reactor and power reactor data Predominantly test reactor data above ft of 3 x 1019 n/cm2  Part

of non-conservatism likely is due to an artifact of high f irradiation  Physical understanding and more data with matching ft for test and power reactor irradiations is needed

U.S. RPV Surveillance Programs 



All U.S. plants have an RPV surveillance program following a version of ASTM E 185 and Appendix H of 10 CFR Part 50 – original intent was for design validation, but data now used to generate embrittlement trend prediction model Current program will generate data for current licensed life, but data at high ft are needed soon to assess potential enhanced embrittlement  70%

of plants have an extended license life for 60 years, and all remaining plants intend to seek extension  Very little surveillance data exist at ft above 5 x 1019 n/cm2

Industry Surveillance Program Adjustments 

Coordinated reactor vessel surveillance program (CRVSP) just initiated  Adjusts

plant-specific capsule withdrawal to assure high ft data are obtained more efficiently  Does not generate more data than current surveillance programs  Does not greatly enhance obtaining data in a reduced time frame 

More high ft data are needed in a more timely manner

Possible Supplemental Program 

In order to gain more high ft data in the shortest time frame possible, a PWR supplemental surveillance program (PSSP) is being considered  PSSP

would utilize broken irradiated Charpy specimens to be irradiated to a higher ft in a host reactor  Reconstituted Charpy specimens would then be used to measure transition temperature shifts 

Concurrent option would be to combine high ft data from test reactor irradiations with appropriate adjustments for f

Other Industry Programs 

EPRI Long Term Operation (LTO) program Originally focused on defining research needs for operation beyond 60 years  Now part of the EPRI base funding and coordinated with existing EPRI programs including RPV integrity 



Cooperative “Nuclear Plant Life Extension Demonstration (NPLED) Project” Constellation Energy Nuclear Group (CENG), EPRI LTO, and DOE Light Water Reactor Sustainability (LWRS) Programs combined under this joint agreement  Two key CENG plants are participating (operating in LR) 

R.E. Ginna – PWR, two-loop, 580 MW  Nine Mile Point Unit 1 – BWR-2, Mark 1, 620 MW 

R.E. Ginna Surveillance Program 

 

Five of the original six surveillance capsules have been tested; forgings and weld metal in each Last tested capsule had ft = 5.8 x 1019 n/cm2 Measured Charpy 41 J shift vs. EONY prediction:   



Linde 80 weld metal – Measured121oC; EONY 111oC EONY under-predicts by 10oC A508-2 forging – Measured 42oC; EONY 29oC EONY under-predicts by 13oC A508-2 forging – Measured 51oC; EONY 29oC EONY under-predicts by 22oC

A couple of broken Charpy halves from the three highest ft capsules for weld and one forging material have been sent to ORNL for atom probe tomography (APT) and small angle neutron scattering (SANS) as part of DOE LWRS

R.E. Ginna Surveillance Results Compared to EONY & Kirk Models

Atom Probe Tomography (APT) of Mn-Ni Irradiation Clusters in a Model Alloy Mn-Ni clusters, predicted in the 1990s , also have been identified in RPV steels (with little or no Cu) and may act as an additional embrittlement mechanism, particularly at high ft

Test Reactor Irradiations at ATR-2 



 



UCSB-ORNL joint project funded by DOE and using ATR-2 under the National Scientific User Facility (NSUF) With a peak f ≈ 3.3 x1012 n/cm2-s at I-22 position, ft ≈ 1020 n/cm2 can be achieved in 1.2 years Temperature zones: 250, 270, 290 and 310 oC Active temperature control with variable He-Ar gasgap-mixture and monitored with 28 thermocouples Gd shielding of thermal neutron for reducing specimen activation

Large Number of Alloys & Specimens Included in ATR-2 Experiment 



Total of ≈ 180 RPV steel alloys including IVAR program (CM, L-series) and newly prepared slit melt model steels (SMMS), and commercial surveillance program welds and plates and new split melt alloys Specimen types  ≈ 1000 Multi purpose disc coupons with 20 mm diameter  ≈ 400 Miniature tensile specimens (SS-J2) in 20-mm diameter containers  42 20-mm diameter disc compact tension (DCT) specimens (three alloys)

20.0

Overlap of Existing Test Reactor Data with ATR-2 Experiment

Selection of Surveillance Materials 







Highest ft materials tested in PWR surveillance programs Covers range of materials in operating PWRs (welds, plates, and forgings) One weld wire heat from two different weldments with greatly different copper contents (1P3571) Non-irradiated archive material was readily obtainable

Surveillance Materials Added to ATR-2 Plant

Material

Heat Number

Cu-Ni Composition, wt%

Farley Unit 2

SMAW

BOLA

0.03-0.9

Farley Unit 2

Plate, SA533B-1

C7466-1

0.2-0.6

V.C. Summer

Linde 124 Weld

4P4784

0.05-0.91

Kewaunee

Linde 1092 Weld

1P3571

0.22-0.72

Maine Yankee

Linde 1092 Weld

1P3571

0.36-0.78

Farley Unit 1

Linde 0091Weld

33A277

0.14-0.19

Beaver Valley Unit 2

Plate, SA533B-1

B9004-1

0.05-0.56

Kewaunee

Forging, SA508-2

B6307-1

0.06-0.75

Turkey Point Unit 4

Linde 80 Weld

71249 (SA1094)

0.29-0.6

Capsule Layout

1 2

3

180 materials plus different multiples 1661 specimens in 13 capsules 7 dosimetry modules 7 temperature/f variations 250 - 310 ºC 4 – 19x 1019 n/cm2 (for ≈ 390 FPI days) Nominal Target ft

Capsule ID

Materials

Target Temp.

UCSB-1

coupon/tensile

290 ¼C

low 4.2

UCSB-2

coupon/tensile

290 ¼C

low 6.2

UCSB-3

coupon/tensile

290 ¼C

med 8.8

UCSB-4

coupon/tensile

270 ¼C

med 10.3

UCSB-5

coupon/tensile

250 ¼C

med/hi 10.9

UCSB-6

DCT

290 ¼C

hi 11.7

UCSB-7

coupon/tensile

290 ¼C

hi 12.2

UCSB-8

coupon/tensile

290 ¼C

hi 12.3

UCSB-9

DCT

290 ¼C

hi 11.7

UCSB-10

coupon/tensile

310 ¼C

med/hi 11.0

UCSB-11

coupon/tensile

290 ¼C

med 9.8

UCSB-12

DCT

290 ¼C

low 7.6

UCSB-13

coupon/tensile

290 ¼C

low 5.5

(x1019n/cm2)

4 5

6

7

8 9

10 11 12

ATR-2 Coupon & Tensile Summary 290°C high flux

290°C med flux

disc coupons

31split melt commercial model alloys

78

10 simple model alloys

30

16 RPV plates/forgings

34

12

35

26 RPV welds

71

57

61

UCSB/ORNL

(surveillance)

290°C low flux

250°C

270°C

310°C

disc coupons

disc coupons

disc coupons

68

7

36

42

9

4

3

3

13

35

3

10

9

41

50

5

23

21

250°C

270°C

310°C

tensiles

disc coupons

tensiles

disc coupons

69

72

71

290°C high flux

290°C med flux

tensiles

2

290°C low flux

disc coupons

tensiles

disc coupons

tensiles

disc coupons

tensiles

disc coupons

disc coupons

disc coupons

56 RR model alloys & H.T. variations

56

17

106

16

115

15

56

9

10

12 RR archival crossover welds & plates

25

Rolls Royce

290°C high flux

Other participants 5 Bettis plate & weld alloys 13 CRIEPI alloys

disc coupons

25

290°C med flux disc coupons

22

290°C low flux disc coupons

5 13

13

13

12

250°C

270°C

310°C

disc coupons

disc coupons

disc coupons

10

5

5

13

13

ATR-2 Fracture Matrix Three sets of disc compact tension specimens, corresponding tensile specimens and multi-purpose coupons

20 mm dia. disc compact tension specimen

D.C.T. matrix

Irrd. Condition

Specimen set

Palisades B weld

290°C, 3.5 E12

14 DCT, 19 tensiles, 3 coupons

UCSB forging (C17 as tempered)

290°C, 3.5 E12

14 DCT, 18 tensiles, 4 coupons

UCSB forging ( LP as tempered)

290°C, 2.1 E12

17 DCT, 17 tensiles, 1 coupon

Multi Purpose Coupons Majority of coupon specimens are in 2 cm diameter disc form; precision punched, ground and polished on both faces and laser engraved with alloy code and serial number:

C19

-Microhardness -Shear punch tests -Atom Probe / LEAP

07

-TEM 0.5mm 2cm

-Neutron & X-ray scattering spectroscopy

Tensile Specimens 16

1.2

4

5

0.5

R1.4

Flat tensile type SSJ2 all dimensions mm

18 tensiles compressed in fitted pocket and capped

Small Specimen Loading Design Small (8mm dia.) discs: three stacks of 10 pressed into holder

Bettis 1cm sq coupons: stack of 5 compressed by lid

Dosimetry wire canisters: pressed into dummy

Advanced Microstructure Characterization Tools to Be Applied      

Atom probe tomography (APT) Small angle neutron scattering (SANS) X-ray diffraction-scattering (XRDS) Resistivity-Seebeck coefficient (RSC) Positron annihilation spectroscopy (PAS) Transmission electron microscopy (TEM)

ATR-2 Capsule Status Test assembly completed in late spring 2011 and installed in ATR-2 in May 2011  Irradiation began on June 7, 2011 and will achieve ft = 0.9  1020 n/cm2 in autumn of 2012  Thermocouple monitors show specimens are generally being irradiated at or close to target temperatures 

Summary 









Plans to operate PWR plants to 80 years or more will require RPV surveillance data at high ft to assure integrity Current surveillance programs have been adjusted and enhanced to generate key data for 60 years, and now consideration is being given for 80 or more years; but the time horizon is at least 12 years Test reactor irradiations have been initiated with key RPV and model alloy steels, which include surveillance program steels irradiated in current power reactor surveillance programs to high ft All of these data are crucial in understanding radiation embrittlement mechanisms and to enable extrapolation of irradiation effects on toughness properties for extended time periods Potential methods for adjusting higher f test reactor data to predict power reactor vessel conditions are expected

Smile Life

When life gives you a hundred reasons to cry, show life that you have a thousand reasons to smile

Get in touch

© Copyright 2015 - 2024 PDFFOX.COM - All rights reserved.