The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels
Данные испытаний на вязкость разрушения образцов-свидетелей корпусных материалов реакторов ВВЭР-1000 АЭС Украины были переоценены с использованием метода Master Curve. Показано, что экспериментальная температурная зависимость параметров вязкости разрушения и разброс значений KJc для материалов в...
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Інститут проблем міцності ім. Г.С. Писаренко НАН України
2010
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| Назва видання: | Проблемы прочности |
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| Цитувати: | The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels / V.M. Revka, E.U. Grynik, L.I. Chyrko // Проблемы прочности. — 2010. — № 6. — С. 105-112. — Бібліогр.: 8 назв. — англ. |
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irk-123456789-1120122017-01-17T03:03:24Z The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels Revka, V.M. Grynik, E.U. Chyrko, L.I. Научно-технический раздел Данные испытаний на вязкость разрушения образцов-свидетелей корпусных материалов реакторов ВВЭР-1000 АЭС Украины были переоценены с использованием метода Master Curve. Показано, что экспериментальная температурная зависимость параметров вязкости разрушения и разброс значений KJc для материалов в необлученном состоянии и после облучения флюенсом 41,2∙10²² , нейтр/м² (E 0,5 МэВ) хорошо согласуются с формой Master Curve, 5- и 95%-ными доверительными границами. Анализ данных для корпуса реактора блока № 1 Хмельницкой АЭС свидетельствует, что при использовании нормативного подхода ПНАЭ Г-7-002-86 существенно недооценивается измеренная вязкость разрушения сварного шва в необлученном состоянии. Температуру T0 , определенную согласно методу Master Curve, сравнивали с критической температурой хрупкости TK0 для корпусных материалов в необлученном состоянии. Установлено, что температура T0 намного ниже TK0 .Кроме того, различие в значениях T0 и TK0 для материалов существенно разное. Построена корреляционная зависимость для температур T28 J, определенных по результатам испытаний стандартных образцов Шарпи, и T0 , полученных при испытаниях образцов Шарпи с трещиной на вязкость разрушения. Анализ показал, что результаты испытаний образцов Шарпи с усталостной трещиной могут давать неконсервативную оценку вязкости разрушения материалов корпусов реакторов ВВЭР-1000. Дані випробувань на в’язкість руйнування зразків-свідків корпусних матеріалів реакторів ВВЕР-1000 АЕС України було переоцінено за допомогою методу Master Curve. Показано, що експериментальна температурна залежність параметрів в’язкості руйнування і розкид значень KJc для матеріалів у неопроміненому стані та після опромінення флюенсом 41, 2∙10²² нейтр/м² (E 0,5 МеВ) добре узгоджуються з формою Master Curve, 5- і 95%-ними довірчими межами. Аналіз даних для корпусу реактора блока № 1 Хмельницької АЕС свідчить, що при використанні нормативного підходу ПНАЕ Г-7-002-86 суттєво недооцінюється визначена в’язкість руйнування зварного шва в неопроміненому стані. Температуру T0 , що визначена за методом Master Curve, порівнювали з критичною температурою крихкості TK 0 для корпусних матеріалів у неопроміненому стані. Установлено, що температура T0 значно нижча за TK 0 . Окрім того, різниця у значеннях T0 і TK 0 для матеріалів суттєва. Побудовано кореляційну залежність для температур T28 J , що визначені за результатами випробувань стандартних зразків Шарпі, та T0 , отриманих при випробуваннях зразків Шарпі з тріщиною на в’язкість руйнування. Аналіз показав, що результати випробувань зразків Шарпі з тріщиною втоми можуть давати неконсервативну оцінку в’язкості руйнування матеріалів корпусів реакторів ВВЕР-1000. 2010 Article The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels / V.M. Revka, E.U. Grynik, L.I. Chyrko // Проблемы прочности. — 2010. — № 6. — С. 105-112. — Бібліогр.: 8 назв. — англ. 0556-171X http://dspace.nbuv.gov.ua/handle/123456789/112012 539.4 en Проблемы прочности Інститут проблем міцності ім. Г.С. Писаренко НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
Научно-технический раздел Научно-технический раздел |
| spellingShingle |
Научно-технический раздел Научно-технический раздел Revka, V.M. Grynik, E.U. Chyrko, L.I. The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels Проблемы прочности |
| description |
Данные испытаний на вязкость разрушения образцов-свидетелей корпусных
материалов реакторов ВВЭР-1000 АЭС Украины были переоценены с использованием метода Master Curve. Показано, что экспериментальная температурная зависимость параметров вязкости разрушения и разброс значений KJc
для материалов в необлученном состоянии и после облучения флюенсом
41,2∙10²² , нейтр/м² (E 0,5 МэВ) хорошо согласуются с формой Master
Curve, 5- и 95%-ными доверительными границами. Анализ данных для корпуса реактора блока № 1 Хмельницкой АЭС свидетельствует, что при использовании нормативного подхода ПНАЭ Г-7-002-86 существенно недооценивается измеренная вязкость разрушения сварного шва в необлученном состоянии. Температуру T0 , определенную согласно методу Master Curve, сравнивали с критической температурой хрупкости TK0 для корпусных материалов в
необлученном состоянии. Установлено, что температура T0 намного ниже
TK0 .Кроме того, различие в значениях T0 и TK0 для материалов существенно
разное. Построена корреляционная зависимость для температур T28 J, определенных по результатам испытаний стандартных образцов Шарпи, и T0 ,
полученных при испытаниях образцов Шарпи с трещиной на вязкость разрушения. Анализ показал, что результаты испытаний образцов Шарпи с усталостной трещиной могут давать неконсервативную оценку вязкости разрушения материалов корпусов реакторов ВВЭР-1000. |
| format |
Article |
| author |
Revka, V.M. Grynik, E.U. Chyrko, L.I. |
| author_facet |
Revka, V.M. Grynik, E.U. Chyrko, L.I. |
| author_sort |
Revka, V.M. |
| title |
The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels |
| title_short |
The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels |
| title_full |
The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels |
| title_fullStr |
The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels |
| title_full_unstemmed |
The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels |
| title_sort |
use of master curve method for statistical re-evaluation of surveillance test data for wwer-1000 reactor pressure vessels |
| publisher |
Інститут проблем міцності ім. Г.С. Писаренко НАН України |
| publishDate |
2010 |
| topic_facet |
Научно-технический раздел |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/112012 |
| citation_txt |
The Use of Master Curve Method for Statistical Re-Evaluation of Surveillance Test Data for WWER-1000 Reactor Pressure Vessels / V.M. Revka, E.U. Grynik, L.I. Chyrko // Проблемы прочности. — 2010. — № 6. — С. 105-112. — Бібліогр.: 8 назв. — англ. |
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Проблемы прочности |
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| fulltext |
UDC 539.4
The Use of Master Curve Method for Statistical Re-Evaluation of
Surveillance Test Data for WWER-1000 Reactor Pressure Vessels
V. M. Revka, E. U. Grynik, and L. I. Chyrko
Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv, Ukraine
ÓÄÊ 539.4
Âèêîðèñòàííÿ ìåòîäó Master Curve äëÿ ñòàòèñòè÷íî¿ ïåðåîö³íêè
äàíèõ âèïðîáóâàíü çðàçê³â-ñâ³äê³â äëÿ êîðïóñ³â ðåàêòîð³â
ÂÂÅÐ-1000
Â. Ì. Ðåâêà, Å. Ó. Ãðèí³ê, Ë. ². ×èðêî
²íñòèòóò ÿäåðíèõ äîñë³äæåíü ÍÀÍ Óêðà¿íè, Êè¿â, Óêðà¿íà
Äàí³ âèïðîáóâàíü íà â’ÿçê³ñòü ðóéíóâàííÿ çðàçê³â-ñâ³äê³â êîðïóñíèõ ìàòåð³àë³â ðåàêòîð³â
ÂÂÅÐ-1000 ÀÅÑ Óêðà¿íè áóëî ïåðåîö³íåíî çà äîïîìîãîþ ìåòîäó Master Curve. Ïîêàçàíî, ùî
åêñïåðèìåíòàëüíà òåìïåðàòóðíà çàëåæí³ñòü ïàðàìåòð³â â’ÿçêîñò³ ðóéíóâàííÿ ³ ðîçêèä
çíà÷åíü KJc äëÿ ìàòåð³àë³â ó íåîïðîì³íåíîìó ñòàí³ òà ï³ñëÿ îïðîì³íåííÿ ôëþåíñîì
41, 2 1022� íåéòð/ì2 (E � 0,5 ÌåÂ) äîáðå óçãîäæóþòüñÿ ç ôîðìîþ Master Curve, 5- ³ 95%-íèìè
äîâ³ð÷èìè ìåæàìè. Àíàë³ç äàíèõ äëÿ êîðïóñó ðåàêòîðà áëîêà ¹ 1 Õìåëüíèöüêî¿ ÀÅÑ ñâ³ä÷èòü,
ùî ïðè âèêîðèñòàíí³ íîðìàòèâíîãî ï³äõîäó ÏÍÀÅ Ã-7-002-86 ñóòòºâî íåäîîö³íþºòüñÿ âèçíà-
÷åíà â’ÿçê³ñòü ðóéíóâàííÿ çâàðíîãî øâà â íåîïðîì³íåíîìó ñòàí³. Òåìïåðàòóðó T0 , ùî âèçíà-
÷åíà çà ìåòîäîì Master Curve, ïîð³âíþâàëè ç êðèòè÷íîþ òåìïåðàòóðîþ êðèõêîñò³ TK0 äëÿ
êîðïóñíèõ ìàòåð³àë³â ó íåîïðîì³íåíîìó ñòàí³. Óñòàíîâëåíî, ùî òåìïåðàòóðà T0 çíà÷íî
íèæ÷à çà TK0 . Îêð³ì òîãî, ð³çíèöÿ ó çíà÷åííÿõ T0 ³ TK0 äëÿ ìàòåð³àë³â ñóòòºâà. Ïîáóäîâàíî
êîðåëÿö³éíó çàëåæí³ñòü äëÿ òåìïåðàòóð T28 J , ùî âèçíà÷åí³ çà ðåçóëüòàòàìè âèïðîáóâàíü
ñòàíäàðòíèõ çðàçê³â Øàðï³, òà T0 , îòðèìàíèõ ïðè âèïðîáóâàííÿõ çðàçê³â Øàðï³ ç òð³ùèíîþ
íà â’ÿçê³ñòü ðóéíóâàííÿ. Àíàë³ç ïîêàçàâ, ùî ðåçóëüòàòè âèïðîáóâàíü çðàçê³â Øàðï³ ç òð³ùè-
íîþ âòîìè ìîæóòü äàâàòè íåêîíñåðâàòèâíó îö³íêó â’ÿçêîñò³ ðóéíóâàííÿ ìàòåð³àë³â êîðïóñ³â
ðåàêòîð³â ÂÂÅÐ-1000.
Êëþ÷îâ³ ñëîâà: ðåàêòîð ÂÂÅÐ-1000, êîðïóñí³ ñòàë³, çðàçêè-ñâ³äêè, êðèòè÷íà
òåìïåðàòóðà êðèõêîñò³, çðàçêè Øàðï³, â’ÿçê³ñòü ðóéíóâàííÿ, ìåòîä Master
Curve.
Introduction. An estimation of reactor pressure vessel (RPV) steel fracture
toughness is based on the Charpy impact test data according to a normative method
adopted in Ukraine [1]. The normative approach estimates fracture toughness in the
indirect way. An application of the Master curve methodology allows one to
determine directly the RPV materials fracture toughness. According to Wallin’s
investigations [2], the normative approach results in the highly conservative
fracture toughness estimation for Western RPV steels. Furthermore, an analysis of
the ASME database has shown that application of Master curve method improves
essentially the material fracture toughness estimation [3].
© V. M. REVKA, E. U. GRYNIK, L. I. CHYRKO, 2010
ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6 105
However, for comprehensive use of the Master Curve method, several scientific
and technical issues should be solved. One of them is precise determination of
fracture toughness parameters when testing such small specimens as precracked
Charpy V-notch (PCVN) ones. This is a critical issue since PCVN specimens are
inserted into the surveillance capsules for Ukrainian nuclear power plants (NPP).
The aim of present work was to re-evaluate the surveillance fracture toughness
test data for Ukrainian NPPs using the Master curve method and compare the
normative (PNAÉ G-7-002-86) with new statistical approaches in viewpoint of
material fracture toughness characterization.
Material and Specimens. The WWER-1000 type RPV steels (15Cr2NiMoVAA
grade) and their welds are included in the current analysis. The content of key
alloying elements and detrimental impurities in RPV materials is presented in
Table 1. These materials are extremely pure with regard to copper and phosphorus.
At the same time welds have high nickel and manganese content which increases
their susceptibility to neutron irradiation in spite of low Cu and P contents. Weld
metal for the Khmelnitsky NPP unit 1 (KhNPP-1) has the highest Ni and Mn
content.
The experimental data used for the analysis were obtained from surveillance
tests for six Ukrainian RPVs: KhNPP-1, three units of South-Ukrainian (SUNPP-1,
SUNPP-2, and SUNPP-3) and two units of Zaporizhzhya nuclear power plant
(ZaNPP-1 and ZaNPP-3).
The fracture toughness data obtained from precracked Charpy specimen tests
were used for the statistical re-evaluation. The Charpy impact test data were used to
determine temperature indices corresponding to the absorbed energy level of 28 J
[4].
Surveillance specimens were irradiated by flux of about 1015 n/(m s2 � ) that
is usual for WWER-1000 type reactor irradiation condition. The fast neutron
(E � 0.5 MeV) fluence for specimens was 4.2 to 412 1022. � n/m2. Irradiation
temperature is about 300�C. Thermal ageing time was 3813 effective days for
thermally aged specimens.
T a b l e 1
Key Alloying Elements and Detrimental Impurities Content in RPV Materials
Unit Chemical element, wt.%
Ni Mn Cu P Ni Mn Cu P
Base metal Weld metal
KhNPP-1 1.12 0.48 0.06 0.007 1.88 0.97 0.02 0.006
SUNPP-1 1.17 0.46 0.05 0.008 1.70 0.94 0.04 0.007
SUNPP-2 1.19 0.44 0.12 0.016 1.74 0.93 0.05 0.012
SUNPP-3 1.12 0.35 0.05 0.008 1.72 0.74 0.06 0.005
ZaNPP-1 1.20 0.48 0.08 0.007 1.10 0.78 0.03 0.005
ZaNPP-3 1.10 0.43 0.05 0.007 1.55 0.67 0.05 0.007
106 ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6
V. M. Revka, E. U. Grynik, and L. I. Chyrko
Statistical Re-Evaluation Procedure. The available fracture toughness data
were analyzed and a censoring procedure according to the ASTM E 1921-97
standard deformation criterion [4] was applied for invalid K Jc values. Then results
for 0.4T specimen thickness were converted to their 1T equivalents using a
thickness correction ratio:
K K K K
B
BJc Jc( ) min ( . ) min
.
/
( ) ,1 0 4
0 4
1
1 4
T T
T
T
� � �
�
�
�
�� (1)
where K min is the lower bound fracture toughness, which for ferritic steel is equal
to 20 MPa m� 1 2/ .
After thickness correction the reference temperatures, T0 , were calculated
using a maximum likelihood method and solving numerically the equation [5]:
i i
ii
n
JT T
T T
Kexp[ . ( )]
exp[ . ( )]
(0 019
11 77 0 019
0
01
�
� �
�
�
� c
i
i
ii
T T
T T
� �
� �
20 0 019
11 77 0 019
4
0
0
5
) exp[ . ( )]
{ exp[ . ( )]}�
� �
1
0
n
, (2)
where
i �1 when K Jc value is valid and
i �0 when K Jc value does not meet
the ASTM E 1921 standard deformation criterion with M �30. Finally, the Master
curves, 5 and 95% tolerance bounds for materials were obtained.
Fracture Toughness Test Results for the SUNPP-1. Surveillance test data
for SUNPP-1 were re-evaluated using the Master curve approach. In this analysis,
three irradiated sets and one thermally aged set are considered. Surveillance
specimens from the 1st and 2nd withdrawals were tested at the Russian Research
Centre Kurchatov Institute. Testing of surveillance specimens from the 3rd
withdrawal was performed at the Institute for Nuclear Research of the National
Academy of Sciences of Ukraine. The results of re-evaluation are shown in Figs. 1
and 2, where the fracture toughness data are presented in normalized temperature
coordinates. The Master curves, 5 and 95% tolerance bounds for materials are
drawn together with the experimental K Jc values. As seen, the temperature
dependencies of fracture toughness parameters and the statistical scatter of K Jc
values for WWER-1000 RPV steels are in a good agreement with the Master curve
and 95% tolerance bounds.
The Comparison of Normative and Master Curve Approaches. In earlier
investigations [6], it was found that the radiation embrittlement rate of KhNPP-1
RPV weld metal is higher than the design one. The main reason is the high Ni and
Mn content in the material. It means this weld may limit the RPV design life or
prevent the NPP service life extension. On the other hand, it is known that the
normative approach estimates very conservatively the western RPV steel fracture
toughness in some cases [3], and the application of the Master curve methodology
allows us to improve the estimation of unirradiated RPV material fracture toughness.
Taking into account the above-mentioned issues we have compared the
normative PNAÉ G-7-002-86 and statistical Master curve approach in viewpoint of
the fracture toughness assessment for KhNPP-1 weld metal. At first, the normative
ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6 107
The Use of Master Curve Method ...
K cI curve was indexed by the critical brittleness temperature, TK 0 , obtained from
Charpy impact tests only. The design K cI curve for WWER-1000 type RPV welds
has a form [ ] exp[ . ( )].K T Tc KI 3 035 53 0 0217� � � Temperature TK 0 was
determined by the manufacturer of the pressure vessel at the time of RPV material
certification.
After the statistical re-evaluation a 5% Master curve tolerance bound that has
a form K T TJc( . ) . . exp[ . ( )]0 05 025 4 37 8 0 019� � � and the reference temperature, T0 ,
were obtained. A margin was added to cover the uncertainty in T0 that is
associated with the use of a small number of specimens to determine temperature
T0 . Both curves were compared with the thickness-corrected K Jc values based on
the precracked Charpy specimens test data. It is noteworthy that the 5% Master
curve tolerance bound and design K cI curve have almost the same shape.
The results of comparison are shown in Fig. 3. As seen, the normative
approach underestimates essentially the measured fracture toughness in comparison
with the Master curve. A shift between curves is about 50�C. Obviously the use of
108 ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6
V. M. Revka, E. U. Grynik, and L. I. Chyrko
Fig. 1. Master curve for base metal (SUNPP-1).
Fig. 2. Master curve for weld metal (SUNPP-1).
highly conservative data for the RPV integrity assessment may result in unnecessary
limitations of the operational conditions and service life of the reactor pressure
vessel. In this case, an application of the Master curve and temperature T0
calculated from fracture mechanics test data allows one to solve this problem.
The Comparison of Measured Values of TK 0 and T0 . The TK 0 and T0
values are used as temperature indices for the fracture toughness curves. In other
words, these temperatures locate a K cI curve on the temperature axis. In order to
understand to what extent these temperatures correspond to each other, a comparison
of measured values of TK 0 and T0 was made. Figures 4 and 5 demonstrate the
result of the comparison. We can see that temperature T0 is much lower than TK 0
in the most cases. Furthermore, a difference between T0 and TK 0 values varies
essentially from one material to another.
Obviously a conservatism level defined according to the normative approach
also varies considerably from one material to another. Therefore the temperature
TK 0 is not appropriate as an indexing parameter for the K cI curve. Unlike the
normative approach, the Master curve method allows one to establish the same
conservatism level for different RPV materials.
Fig. 3. Comparison of 5% Master curve tolerance bound (solid line) with normative K cI curve
(dashed line) in regard to the measured fracture toughness parameters.
Fig. 4. Comparison of TK 0 and T0 temperatures for the unirradiated base metal.
ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6 109
The Use of Master Curve Method ...
The Correlation between T28J and T0 Temperatures. According to
Wallin’s results [7], the correlation for RPV steels between T28J and T0 values
has the form T T0 28 18� � �J C (standard deviation is 15�C). The temperature T28 J
is the transition temperature corresponding to Charpy impact energy of 28 J. The
fracture toughness data used to determine the correlation were based on the 25 mm
thickness specimen testing.
At present work we have analyzed a relationship between T28 J temperatures
defined from the Charpy energy curves and T0 values calculated from the
precracked Charpy specimen tests. Both the unirradiated and irradiated up to
fluence ~ 41 1022� n/m2 specimens were chosen for the analysis. The correlation
obtained is presented in Fig. 6. Results of the analysis have shown that such a
correlation has the form T T0 28 40� � �J C (standard deviation is 20�C). It means
that T0 values based on precracked Charpy specimen test data tend to be
nonconservative, in comparison with T0 values obtained from larger standard
fracture mechanics specimens (bias is about 20�C). Certainly this is indirect
evidence. In further investigations it would be necessary to perform fracture
mechanics tests of specimens of different sizes and geometry and to estimate in the
direct way a bias for T0 related to the use of PCVN specimen data for the
WWER-1000 RPV steel fracture toughness characterization.
Fig. 5. Comparison of TK 0 and T0 temperatures for the unirradiated weld metal.
Fig. 6. Correlation between temperatures T28J and T0.
110 ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6
V. M. Revka, E. U. Grynik, and L. I. Chyrko
The fact that PCVN specimen test data may underestimate actual material
fracture toughness can be explained by the constraint (crack-front triaxiality) loss
effect. Based on the stochastic simulation it was found [8] that if constraint loss
occurs at PCVN specimen testing the derived T0 has a lower value than that
determined for a data set of fracture toughness values measured under full
constraint conditions (small-scale yielding conditions). Thus, the T0 shift due to
constraint loss occurs in only one direction (reducing the T0 temperature). For a
relatively tough and moderate strain-hardening materials the decrease in T0 due to
constraint loss effect may amount to 20�C when the E 1921 deformation limit M
is equal to 30 [8].
Conclusions. The surveillance fracture toughness test data for WWER-1000
reactor pressure vessel materials from Ukrainian NPPs were re-evaluated using the
Master curve methodology. The fracture toughness data were obtained from
precracked Charpy specimens testing. Moreover, the Master curve approach was
compared to a normative PNAÉ G-7-002-86 method, in viewpoint of adequate
estimation of RPV steel fracture toughness. Results of analysis allow us to make
the following conclusions.
1. The Master curve, 5 and 95% tolerance bounds describe adequately the
temperature dependence of fracture toughness parameters and the statistical scatter
of K Jc values for WWER-1000 RPV steels both in unirradiated condition and
after irradiation up to neutron fluence 41 1022� n/m2 (E � 0.5 MeV).
2. The normative approach estimates highly conservatively the unirradiated
weld metal fracture toughness for Khmelnitsky NPP unit 1, in comparison with the
Master curve method. A shift between the design K cI curve and 5% Master curve
tolerance bound is about 50�C. The application of the initial critical brittleness
temperature, TK 0 , to the assessment of reactor pressure vessel integrity may
unnecessarily limit the operational conditions and service life of the Khmelnitsky
NPP.
3. Precracked Charpy specimen test data may result in the nonconservative
estimation of fracture toughness for WWER-1000 type RPV materials (bias is
about 20�C). This conclusion has been made in the indirect way. Therefore it is
necessary to perform the additional tests of specimens with different geometry and
directly estimate a bias for T0 related to the use of PCVN specimen data for the
RPV steel fracture toughness characterization.
Ð å ç þ ì å
Äàííûå èñïûòàíèé íà âÿçêîñòü ðàçðóøåíèÿ îáðàçöîâ-ñâèäåòåëåé êîðïóñíûõ
ìàòåðèàëîâ ðåàêòîðîâ ÂÂÝÐ-1000 ÀÝÑ Óêðàèíû áûëè ïåðåîöåíåíû ñ èñïîëü-
çîâàíèåì ìåòîäà Master Curve. Ïîêàçàíî, ÷òî ýêñïåðèìåíòàëüíàÿ òåìïåðàòóð-
íàÿ çàâèñèìîñòü ïàðàìåòðîâ âÿçêîñòè ðàçðóøåíèÿ è ðàçáðîñ çíà÷åíèé K Jc
äëÿ ìàòåðèàëîâ â íåîáëó÷åííîì ñîñòîÿíèè è ïîñëå îáëó÷åíèÿ ôëþåíñîì
41 2 1022, � íåéòð/ì 2 (E � 0,5 ÌýÂ) õîðîøî ñîãëàñóþòñÿ ñ ôîðìîé Master
Curve, 5- è 95%-íûìè äîâåðèòåëüíûìè ãðàíèöàìè. Àíàëèç äàííûõ äëÿ êîð-
ïóñà ðåàêòîðà áëîêà ¹ 1 Õìåëüíèöêîé ÀÝÑ ñâèäåòåëüñòâóåò, ÷òî ïðè èñïîëü-
çîâàíèè íîðìàòèâíîãî ïîäõîäà ÏÍÀÝ Ã-7-002-86 ñóùåñòâåííî íåäîîöåíèâà-
ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6 111
The Use of Master Curve Method ...
åòñÿ èçìåðåííàÿ âÿçêîñòü ðàçðóøåíèÿ ñâàðíîãî øâà â íåîáëó÷åííîì ñîñòîÿ-
íèè. Òåìïåðàòóðó T0 , îïðåäåëåííóþ ñîãëàñíî ìåòîäó Master Curve, ñðàâíè-
âàëè ñ êðèòè÷åñêîé òåìïåðàòóðîé õðóïêîñòè TK 0 äëÿ êîðïóñíûõ ìàòåðèàëîâ â
íåîáëó÷åííîì ñîñòîÿíèè. Óñòàíîâëåíî, ÷òî òåìïåðàòóðà T0 íàìíîãî íèæå
TK 0 . Êðîìå òîãî, ðàçëè÷èå â çíà÷åíèÿõ T0 è TK 0 äëÿ ìàòåðèàëîâ ñóùåñòâåííî
ðàçíîå. Ïîñòðîåíà êîððåëÿöèîííàÿ çàâèñèìîñòü äëÿ òåìïåðàòóð T28 J , îïðå-
äåëåííûõ ïî ðåçóëüòàòàì èñïûòàíèé ñòàíäàðòíûõ îáðàçöîâ Øàðïè, è T0 ,
ïîëó÷åííûõ ïðè èñïûòàíèÿõ îáðàçöîâ Øàðïè ñ òðåùèíîé íà âÿçêîñòü ðàçðó-
øåíèÿ. Àíàëèç ïîêàçàë, ÷òî ðåçóëüòàòû èñïûòàíèé îáðàçöîâ Øàðïè ñ óñòà-
ëîñòíîé òðåùèíîé ìîãóò äàâàòü íåêîíñåðâàòèâíóþ îöåíêó âÿçêîñòè ðàçðó-
øåíèÿ ìàòåðèàëîâ êîðïóñîâ ðåàêòîðîâ ÂÂÝÐ-1000.
1. PNAÉ G-7-002-86. Strength Calculation Norm for Nuclear Power Plant
Equipment and Piping [in Russian], Énergoatomizdat, Moscow (1989).
2. K. Wallin, “Statistical re-evaluation of the ASME K cI and K RI fracture
toughness reference curves,” Nucl. Eng. Design, 193, 317–326 (1999).
3. M. Kirk and M. Mitchell, “Potential roles for the Master curve in regulatory
application,” Int. J. Press. Vess. Piping, 78, 111–123 (2001).
4. ASTM E 1921-97. Standard Test Method for Determination of Reference
Temperature, T0 , for Ferritic Steels in the Transition Range, ASTM (1997).
5. K. Wallin, “Validity of small specimen fracture toughness estimates neglecting
corrections of constraint,” in: Constraint Effects in Fracture Theory and
Applications, ASTM STP 1244, Philadelphia (1995), pp. 519–537.
6. E. Grynik, V. Gukalova, L. Chyrko, et al., “Results from surveillance program
and their analysis,” in: Proc. of the IAEA Specialists Meeting Irradiation
Embrittlement and Mitigation (IWG-LMNPP-01/2, May 14–17, 2002,
Gloucester, UK), Vienna (2002), pp. 277–284.
7. K. Wallin, “A simple theoretical Charpy-V – K cI correlation for irradiation
embrittlement,” in: Innovative Approaches to Irradiation Damage and Fracture
Analysis, PVP (1989), Vol. 170, pp. 93–100.
8. C. Ruggieri, R. H. Dodds, and K. Wallin, “Constraint effects on reference
temperature, T0 , for ferritic steels in the transition region,” Eng. Fract. Mech.,
60, 19–36 (1998).
Received 24. 04. 2008
112 ISSN 0556-171X. Ïðîáëåìû ïðî÷íîñòè, 2010, ¹ 6
V. M. Revka, E. U. Grynik, and L. I. Chyrko
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/NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken voor kwaliteitsafdrukken op desktopprinters en proofers. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 5.0 en hoger.)
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/PTB <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>
/SUO <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>
/SVE <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>
/ENU (Use these settings to create Adobe PDF documents for quality printing on desktop printers and proofers. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.)
>>
/Namespace [
(Adobe)
(Common)
(1.0)
]
/OtherNamespaces [
<<
/AsReaderSpreads false
/CropImagesToFrames true
/ErrorControl /WarnAndContinue
/FlattenerIgnoreSpreadOverrides false
/IncludeGuidesGrids false
/IncludeNonPrinting false
/IncludeSlug false
/Namespace [
(Adobe)
(InDesign)
(4.0)
]
/OmitPlacedBitmaps false
/OmitPlacedEPS false
/OmitPlacedPDF false
/SimulateOverprint /Legacy
>>
<<
/AddBleedMarks false
/AddColorBars false
/AddCropMarks false
/AddPageInfo false
/AddRegMarks false
/ConvertColors /NoConversion
/DestinationProfileName ()
/DestinationProfileSelector /NA
/Downsample16BitImages true
/FlattenerPreset <<
/PresetSelector /MediumResolution
>>
/FormElements false
/GenerateStructure true
/IncludeBookmarks false
/IncludeHyperlinks false
/IncludeInteractive false
/IncludeLayers false
/IncludeProfiles true
/MultimediaHandling /UseObjectSettings
/Namespace [
(Adobe)
(CreativeSuite)
(2.0)
]
/PDFXOutputIntentProfileSelector /NA
/PreserveEditing true
/UntaggedCMYKHandling /LeaveUntagged
/UntaggedRGBHandling /LeaveUntagged
/UseDocumentBleed false
>>
]
>> setdistillerparams
<<
/HWResolution [2400 2400]
/PageSize [612.000 792.000]
>> setpagedevice
|