ML15331A202

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Official Exhibit - NYS000518-00-BD01 - Kirk, Mark and Sheng, Simon, USNRC, Assessment of BTP 5-3 Protocols to Estimate Rtndt(U) and Use, (June 4, 2014) (ML14163A524)
ML15331A202
Person / Time
Site: Indian Point  Entergy icon.png
Issue date: 06/04/2014
From:
State of NY, Office of the Attorney General
To:
Atomic Safety and Licensing Board Panel
SECY RAS
References
RAS 27910, ASLBP 07-858-03-LR-BD01, 50-247-LR, 50-286-LR
Download: ML15331A202 (37)
v • d • e


Text

United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of: Entergy Nuclear Operations, Inc.

(Indian Point Nuclear Generating Units 2 and 3)

ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 l 05000286 Exhibit #: NYS000518-00-BD01 Identified: 11/5/2015 NYS000518 Admitted: 11/5/2015 Withdrawn:

Rejected: Stricken:

Submitted: June 9, 2015 Other:

ML14163A524

Assessment of BTP 5-3 Protocols to Estimate RTNDT(u) and USE Mark Kirk Simon Sheng Senior Materials Engineer Senior Materials Engineer RES/DE/CIB NRR/DE/EVIB mark.kirk@nrc.gov simon.sheng@nrc.gov NRC/EPRI Annual Materials Issue Program Information Exchange Meeting 4th June 2014 Rockville, Maryland, USA

Outline of Presentation

  • Un-Irradiated RTNDT (RTNDT(u)) & Un-Irradiated Upper Shelf Energy (USE) definitions & estimates
  • Background of questions concerning BTP 5-3
  • Staff Assessment Part I - Technical evaluation of BTP 5-3 estimation of RTNDT(u) & USE
  • Staff Assessment Part I - Potentially Affected Plants
  • Next steps

Definitions: RTNDT(u) & USE Specimens notched transverse to RD USE average of all energies > 95%

shear per ASTM E185-82 RT NDT(u)= MAX {T NDT , T35 / 50 60}

per ASME NB-2331 Break: Crack No-Break: Fracture completely severs (darkened region) does tension surface of not extend to the sides specimen. of the specimen Temperature NDT is the lowest temperature of no-break performance

RTNDT(u) & USE Estimated by NUREG-0800 BTP 5-3 Approximations Position 1.1(4)

Positions 1.1(1) & 1.1(2)

Position 1.1(3)

RT NDT(u)= MAX {T NDT , T35 / 50 60}

per ASME NB-2331 Position 1.2 USE average of all energies > 95%

shear per ASTM E185-82

Background of Questions Concerning BTP 5-3

  • AREVA Letter (30 Jan 2014, AREVA Ref. NRC:14:004) & PVP Paper (PVP2014-28897) claim Position 1.1(4) of BTP 5.3 is sometimes non-conservative for A508-2 forgings
  • Literature search reveals 1983 EG&G report & 1985 IJPVP paper

- Evaluation of BTP 5-3 (then MTEB 5-2) for NRC

- Conclusions

  • Always conservative

- Position 1.1(1): estimates TNDT

- Position 1.1(2): estimates TNDT

  • Sometime non-conservative

- Position 1.1(3): estimates TCVE(50/35)

- Position 1.1(4): estimates RTNDT

- Position 1.2: estimates USE

Background of Questions Concerning BTP 5-3

  • AREVA Letter (30 Jan 2014, AREVA Ref. NRC:14:004) & PVP Paper (PVP2014-28897) claim Position 1.1(4) of BTP 5.3 is sometimes non-conservative for A508-2 forgings
  • Literature search reveals 1983 EG&G report & 1985 IJPVP paper

- Evaluation of BTP 5-3 (then MTEB 5-2) for NRC

- Conclusions

  • Always conservative

- Position 1.1(1): estimates TNDT

- Position 1.1(2): estimates TNDT

  • Sometime non-conservative

- Position 1.1(3): estimates TCVE(50/35)

- Position 1.1(4): estimates RTNDT

- Position 1.2: estimates USE

NRC Staff Assessment Process Part I: Technical evaluation of BTP Part II: Assessment of 5-3 estimation of RTNDT(u) and USE applicability to plants

  • Data sources
  • Query RVID

- Processed data (T50, USE, ) from - RTNDT(u): establishes BTP 5-3 1983 EG&G report use, but not which position was

- Raw data (CVE, MLE, temp) in used both specimen orientations from - USE: establishes BTP 5-3 use surveillance reports (stored in REAP)

  • Search for documents

- Raw data (NDTT) from RVID refs. referenced by RVID in ADAMS legacy

  • Focus on - Focus on plants closest to PTS

- Plates & forgings only (50.61) limit, these being most

  • No plants have used BTP 5-3 for prone to influence by potential welds non-conservatisms

- Positions identified as sometimes - References establish which non-conservative in 1983 by position of BTP 5-3 was used EG&G report for RTNDT(u)

  • Position 1.1(3): estimates TCVE(50/35)
  • Position 1.1(4): estimates RTNDT
  • Position 1.2: estimates USE

Part I: Technical Evaluation Overview

  • Data sources
  • While similar answers are expected from both sources

- Processed data (T50, USE, )

  • Given the potential impact of this evaluation, going from 1983 EG&G report back to the raw data was seen to be important.

- Raw data (CVE, MLE, temp) 150 A508-2: Heat 527536 from surveillance reports Longitudinal 125 (stored in REAP)

- Raw data (NDTT) from RVID 100 refs. 75 Impact Energy [ft-lbs]

  • Focus on 50 tanh Fit

- Plates & forgings only 25 Data

  • No plants have used BTP 5-3 0 150 for welds Transverse

- Positions identified as 125 sometimes non-conservative 100 by 1983 EG&G report 130°F 47%

  • Position 1.1(3): estimates 75 TCVE(50/35) 50
  • Position 1.1(4): estimates RTNDT 28%

25% tanh Fit

  • Position 1.2: estimates USE 25 43% Data 0

-200 -100 0 100 200 300 Temperature [°F]

Position 1.1(3)

Quotation Tests Required If transversely-oriented Charpy V-notch Longitudinally oriented CVN specimens specimens were not tested, the temperature at which 68 J (50 ft-lbs) and Clear Interpretation 0.89 mm (35 mils) LE would have been Note that this position applies only to conversion between longitudinal obtained on transverse specimens may and transverse Charpy values.

be estimated by one of the following There are two approximations. They may not produce the same criteria: results. They are as follows

- Test results from longitudinally-oriented specimens reduced to 65% of their (a) ETRANS = 0.65xELONG, then calc TC(TRANS) value to provide conservative estimates MLETRANS = 0.65xMLELONG, then calc TC(TRANS-MLE) of values expected from transversely oriented specimens. (b) TC(TRANS) = TC(LONG) + 20 °F

- Temperatures at which 68 J (50 ft-lbs) TC(TRANS-MLE = TC(LONG-MLE) + 20 °F and 0.89 mm (35 mils) LE were obtained on longitudinally-oriented specimens where increased 11 °C (20 °F) to provide a ELONG is CVN energy measured by a longitudinally conservative estimate of the oriented specimen temperature that would have been ETRANS is the estimated CVN for a transversely oriented necessary to obtain the same values on specimen transversely-oriented specimens. TC(LONG) is the temperature at which the minimum of three longitudinal CVN tests exhibits >35 mils AND >50 ft-lbs TC(TRANS) is the estimated temperature at which the minimum of three transverse CVN tests exhibits

>35 mils AND >50 ft-lbs

Position 1.1(3)

Assessing(a): Trans = 0.65xLong

1. Per the BTP, reduce longitudinal measurements to Longitudinal 65% of the measured values Energy
2. Fit Charpy curves

- Energy vs. temperature Transverse =

- Lateral expansion vs. 0.65xLongitudinal temperature Temperature

3. Determine MAX(T50ft-lb, T35mills)
4. Value from Step 3 estimates the transition temperature of transverse data

Position 1.1(3)

Assessing(a): Trans = 0.65xLong Same data plotted two different ways 200 Non-conservative predictons: 33% Plates, 43% Forgings, 36% Overall Non-conservative predictons: 33% Plates, 43% Forgings, 36% Overall 1.0 Transverse T50 Estimate Error [°F]

Plate 0.9 150 Forging 0.8 BTP 5-3 Position 1.1(3) (+20F) 0.7 100 Percentile 0.6 50 Non-conservative 0.5 0.4 0

0.3 Non-conservative 0.2 Plate

-50 Forging 0.1 BTP 5-3 Position 1.1(3) (+20F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Trans T50 est. from Longx0.65 [°F] Transverse T50 Estimate Error [°F]

Position is non-conservative about 36% of the time EG&G Data

Position 1.1(3)

Assessing(a): Trans = 0.65xLong Same data plotted two different ways 200 Non-conservative predictons: 19% Plates, 48% Forgings, 30% Overall 1.0 Non-conservative predictons: 19% Plates, 48% Forgings, 30% Overall Trans. T50ft-lbs&35mills Estimate Error [°F]

Plate 0.9 150 Forging 0.8 BTP 5-3 Position 1.1(3) (0F) 0.7 100 Percentile 0.6 50 Non-conservative 0.5 0.4 0 0.3 Non-conservative 0.2 Plate

-50 Forging 0.1 BTP 5-3 Position 1.1(3) (0F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Trans. T50ft-lbs&35mills est. from Longx0.65 [°F] Transverse T50ft-lbs&35mills estimate error [°F]

T50ft-lbs determines the value of T50ft-lbs&35mills

  • 81% of the time for longitudinal specimens
  • 92% of the time for transverse specimens Position is non-conservative about 30% of the time Raw Data

Position 1.1(3)

Assessing(b): Alternative TC(TRANS) Estimates 250 Mean: T50T = 0.72xT50(e) + 12.5 Bound: T50T = 0.72xT50(e)- 27.5 Plate & Forging 200 Outlier (excluded)

Mean Transverse T50 [°F]

150 Lower Bound 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Trans. T50 from Longx0.65[°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. EG&G Data

Position 1.1(3)

Assessing(a): Alternative TC(TRANS) Estimates 250 Mean: T50&35T = 0.66xT50&35(e) + 13 Bound: T50&35T = 0.66xT50&35(e) - 34 Plate & Forging Transverse T50ft-lbs&35mills [°F]

200 Mean Lower Bound 150 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Trans. T50ft-lb&35mills est. from Longx0.65 [°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. Raw Data

Position 1.1(3)

Assessing(b): TC(TRANS) = TC(LONG) + 20 °F Same data plotted two different ways 200 Non-conservative predictons: 70% Plates, 50% Forgings, 64% Overall 1.0 Non-conservative predictons: 70% Plates, 50% Forgings, 64% Overall Transverse - Longitudinal T50 [°F]

0.9 150 0.8 0.7 100 Percentile 0.6 Non-conservative 50 0.5 0.4 0

0.3 Non-conservative Plate 0.2 Plate

-50 Forging Forging 0.1 BTP 5-3 Position 1.1(3) (+20F) BTP 5-3 Position 1.1(3) (+20F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Longitudinal T50 [°F] Transverse - Longitudinal T50 [°F]

Position is non-conservative about two-thirds of the time EG&G Data

Position 1.1(3)

Assessing(b): TC(TRANS) = TC(LONG) + 20 °F Same data plotted two different ways 200 Non-conservative predictons: 63% Plates, 57% Forgings, 60% Overall 1.0 Non-conservative predictons: 63% Plates, 57% Forgings, 60% Overall 0.9 Trans. - Longl. T50ft-lbs&35mills [°F]

150 0.8 0.7 100 Percentile 0.6 Non-conservative 50 0.5 0.4 0 0.3 Non-conservative Plate 0.2 Plate

-50 Forging Forging 0.1 BTP 5-3 Position 1.1(3) (+20F) BTP 5-3 Position 1.1(3) (+20F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Longitudinal T50ft-lbs&35mills [°F] Transverse - Longitudinal T50ft-lbs&35mills [°F]

T50ft-lbs determines the value of T50ft-lbs&35mills

  • 81% of the time for longitudinal specimens
  • 92% of the time for transverse specimens Position is non-conservative about two-thirds of the time Raw Data

Position 1.1(3)

Assessing(b): Alternative TC(TRANS) Estimates 250 Mean: T50T = 0.58xT50L + 44.7 Lower Bound: T50T = 0.58xT50L + 2.0 Plate & Forging 200 Outlier (excluded)

Mean Transverse T50 [°F]

150 Lower Bound 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Longitudinal T50 [°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. EG&G Data

Position 1.1(3)

Assessing(b): Alternative TC(TRANS) Estimates 250 Mean: T50&35T = 0.68xT50&35L + 35 Low Bound: T50&35T = 0.68xT50&35L - 17 Plate & Forging Transverse T50ft-lbs&35mills [°F]

200 Mean Lower Bound 150 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Longitudinal T50ft-lb&35mills [°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. Raw Data

Position 1.1(4)

Quotation Tests Required If limited Charpy V-notch tests Limited longitudinally oriented CVN tests at a single temperature were performed at a single temperature to confirm that at Interpretation least 41 J (30 ft-lbs) was obtained, Define: TTEST = the temperature at which limited that temperature may be used as longitudinally oriented CVN tests were an estimate of the RTNDT provided conducted CV = absorbed energy observed at TTEST that at least 61J (45 ft-lbs) was IF CV 45 ft-lbs then RTNDT = TTEST obtained if the specimens were ELSE RTNDT = TTEST + 20 °F longitudinally oriented. If the minimum value obtained was less When assessed using data sets for than 61 J (45 ft-lbs), the RTNDT which full Charpy energy curves are may be estimated as 11 °C (20 °F) available, EG&G interpreted Position above the test temperature. 1.1(4) as having 2 possible meanings:

- RTNDT = T45(LONG), and

- RTNDT = T30(LONG) + 20 °F These might not produce the same result. Therefore, both were assessed.

Position 1.1(4)

Assessed for Forgings RTNDT = T30(LONG) + 20 °F RTNDT = T45(LONG) 150 SA-508-2 Forging. RTndt per BTP 5-3 1.1(4) 150 SA-508-2 Forging. RTndt per BTP 5-3 1.1(4)

Estimated RTNDT = T30L+20 [°F]

Estimated RTNDT = T45L [°F]

100 Forging 100 SA-508-2 50 50 Top &

0 0 bottom panel of

-50 -50

-100 -100

-150 Non-Conservative

-150 Non-Conservative each pair

-150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 -150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 are the 1.0 0.9 93% of data under-predicted. Max =-95F 1.0 0.9 93% of data under-predicted. Max =-86F same data 0.8 0.7 0.8 0.7 plotted two different Percentile Percentile 0.6 0.6 Non-Conservative Non-Conservative 0.5 0.5 0.4 0.3 0.4 0.3 ways 0.2 0.2 0.1 0.1 0.0 0.0

-100 -50 0 50 100 150 200 -100 -50 0 50 100 150 200 Error in Estimated RTNDT [°F] Error in Estimated RTNDT [°F]

Position is non-conservative about 90% of the time EG&G Data

Position 1.1(4)

Assessed for Plates RTNDT = T30(LONG) + 20 °F RTNDT = T45(LONG) 150 SA-533B-1 Plate. RTndt per BTP 5-3 1.1(4) 150 SA-533B-1 Plate. RTndt per BTP 5-3 1.1(4)

Estimated RTNDT = T30L+20 [°F]

Estimated RTNDT = T45L [°F]

100 Plate 100 SA-533B-1 50 50 Top &

0 0 bottom

-50 -50 panel of

-100 -100

-150 Non-Conservative

-150 Non-Conservative each pair

-150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 -150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 are the 1.0 0.9 38% of data under-predicted. Max =-38F 1.0 0.9 38% of data under-predicted. Max =-27F same data Non-Conservative Non-Conservative 0.8 0.7 0.8 0.7 plotted 2 different Percentile Percentile 0.6 0.6 0.5 0.5 0.4 0.3 0.4 0.3 ways 0.2 0.2 0.1 0.1 0.0 0.0

-100 -50 0 50 100 150 200 -100 -50 0 50 100 150 200 Error in Estimated RTNDT [°F] Error in Estimated RTNDT [°F]

Position is non-conservative about 40% of the time EG&G Data

Position 1.2 Quotation Tests Required For the beltline region of reactor vessels, Longitudinally oriented CVN specimens tested on the upper shelf.

the upper shelf toughness must account for the effects of neutron radiation. Clear Interpretation Reactor vessel beltline materials must USETRANS = 0.65 x USELONG have Charpy upper shelf energy, in the where transverse direction for base material and along the weld for weld material USELONG is CVN energy measured by longitudinally oriented specimens on according to the ASME Code, of no less the upper shelf than 102 J (75 ft-lbs) initially and must USETRANS is the estimated CVN energy for maintain Charpy upper shelf energy transversely oriented specimens on the upper shelf throughout the life of the vessel of no less than 68 J (50 ft-lbs).

If Charpy upper shelf energy values were not obtained, conservative estimates should be made using results of tests on specimens from the first surveillance capsule removed.

If tests were only made on longitudinal specimens, the values should be reduced to 65% of the longitudinal values to estimate the transverse properties.

Position 1.2 Assessing: USETRANS = 0.65 x USELONG Same data plotted two different ways Non-conservative predictons: 20% Plates, 14% Forgings, 18% Overall 1.0 Non-conservative predictons: 20% Plates, 14% Forgings, 18% Overall 1.4 Transverse / Longitudinal USE Ratio 0.9 1.2 Plate 0.8 Forging 1.0 0.7 BTP 5-3 Position 1.2 (0.65)

Percentile 0.6 0.8 0.5 0.6 0.4 Non-conservative 0.3 0.4 Plate Non-conservative 0.2 0.2 Forging 0.1 BTP 5-3 Position 1.2 (0.65) 0.0 0.0 0 50 100 150 200 250 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Longitudinal Upper Shelf Energy [ft-lbs] Transverse / Longitudinal USE Ratio Position is non-conservative about 18% of the time EG&G Data

Position 1.2 Assessing: USETRANS = 0.65 x USELONG Same data plotted two different ways Non-conservative predictons: 13% Plates, 33% Forgings, 21% Overall 1.0 Non-conservative predictons: 13% Plates, 33% Forgings, 21% Overall 1.4 Transverse / Longitudinal USE Ratio 0.9 1.2 Plate 0.8 Forging 1.0 0.7 BTP 5-3 Position 1.2 (0.65)

Percentile 0.6 0.8 0.5 0.6 0.4 Non-conservative 0.3 0.4 Plate Non-conservative 0.2 0.2 Forging 0.1 BTP 5-3 Position 1.2 (0.65) 0.0 0.0 0 50 100 150 200 250 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Longitudinal Upper Shelf Energy [ft-lbs] Transverse / Longitudinal USE Ratio Position is non-conservative about 21% of the time Raw Data

Position 1.2 Assessing: Alternative USETRANS Estimates 250 Mean: Tuse = 0.61xLuse + 21.2 Lower Bound: Tuse = 0.61xLuse - 22.1 Transverse Upper Shelf Energy [ft-lb]

200 Plate Forging 150 Mean Lower Bound 100 50 0

0 50 100 150 200 250 Longitudinal Upper Shelf Energy [ft-lb]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse USE values in a manner that is always conservative. EG&G Data

Position 1.2 Assessing: Alternative USETRANS Estimates 250 Mean: Tuse = Luse - 36 Lower Bound: Tuse = Luse - 65 Transverse Upper Shelf Energy [ft-lb]

200 Plate Forging 150 Mean Lower Bound 100 50 0

0 50 100 150 200 250 Longitudinal Upper Shelf Energy [ft-lb]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse USE values in a manner that is always conservative. Raw Data

Summary on Part I - Technical Evaluation

  • Positions 1.1(3) and 1.2

- Results of the two studies are similar

- Staff analysis confirms non-conservatism

  • Position 1.1(4)

- EG&G report demonstrates position is non-conservative

- Awaiting NDTT data from Archives to complete staff assessment Forging Non-Conservative Plate Non-Conservative Position of BPT 5-3 Prediction Rate Prediction Rate EG&G Data Raw Data EG&G Data Raw Data (a) TRANS = 0.65xLONG 43% 48% 33% 19%

1.1(3)

(b) TC(TRANS) = TC(LONG) + 20 °F 50% 57% 70% 63%

RTNDT = T45(LONG) 93% TBD 38% TBD 1.1(4)

RTNDT = T30(LONG) + 20 °F 93% TBD 38% TBD 1.2 USETRANS = 0.65 x USELONG 14% 33% 20% 13%

Part II: Assess Potentially Affected Plants - Position 1.1(3)

Plant Identification

  • Search RVID for plants using BTP 5-3 to determine plate (forging) RTNDT(u):

20 operating plants

  • Rank plates (forging) according to the difference between RTPTS at 32 EFPY and 270 °F:

Eight plants have their limiting plates or forgings using BTP5-3 with difference less than 100 °F.

Plant-specific evaluation results

  • The majority of the plants did not specify which BTP 5-3 B1.1 position was used in determining their RTNDT(u) values
  • Details of calculation of RTNDT(u) values are not available.
  • One plant has full transverse Charpy data and the staff confirmed that BTP 5-3 was not used , so it will be dropped from the list
  • A few plants have full longitudinal Charpy data

- The staffs RTNDT(u) values using lower bound Charpy data and linear interpolation between two temperatures are lower than the licensees value by 10 °F

  • A few plants may have PTS concern because the RTPTS values are below 270 °F by less than 75 °F

- In one case, the longitudinal Charpy data for one plate are significantly higher than other plates, indicating potential mislabeling

Why do we use the Selecting criterion of 75 °F?

- Identify raw data with the greatest conservatism and non-conservatism Wattss Bar 1 - greatest non-conservatism Millstone 2 - greatest conservatism 200 Non-conservative predictons: 63% Plates, 57% Forgings, 60% Overall Trans. - Longl. T50ft-lbs&35mills [°F]

150 Watts Bar 1 100 Non-conservative 50 0

Plate

-50 Forging BTP 5-3 Position 1.1(3) (+20F)

-100

-50 -25 0 25 50 75 100 125 Longitudinal T50ft-lbs&35mills [°F]

Closer Look at the Charpy Data with the Greatest Non-Conservatism 150 150 125 125 Impact Energy [ft-lbs] Impact Energy [ft-lbs]

100 100 75 75 50 50 tanh Fit 25 25 tanh Fit Data Data 0 0

-200 -100 0 100 200 300 -200 -100 0 100 200 300 Temperature [F] Temperature [F]

T50flb T35mill T50flb T35mill T50flb T35mill

[oF] [oF] [oF] [oF] [oF] [oF]

114.5 83.0 31 - -15.5 -9.4 Transverse Data Longitudinal Data X .65 Longitudinal Data

Determine the RTNDT for the Raw Data with the Greatest Non-Conservatism

  • Nil-ductility transition temperature (NDTT): -22 °F
  • Official RTNDT(u) value: = 54.5 °F (114.5 °F - 60 °F)
  • RTNDT(u) based on BTP 5-3B1.1(3)a: -22 °F (At 31 °F, the equivalent Charpy energy (.65 x longitudinal data) is 50 ft-lb; RTNDT = NDTT)
  • RTNDT(u) based on BTP 5-3B1.1(3)b: -22 °F (At -15.5 °F, the Charpy energy is 50 ft-lb; since the adjusted temp is (-15.5 °F + 20 °F ), less than (-22°F +

60 °F), RTNDT = NDTT)

Summary on the Study Focusing on the Raw Data with the Highest Non-Conservatism

  • The highest non-conservative raw data is about 75 °F
  • RTNDT determination is not sensitive to whether B1.1(3)a or B1.1(3)b is used for this case
  • RTNDT determination is affected by whether curve fitting of the entire Charpy data or hand calculations based on Charpy data at two temperatures are used

Part II: Assess Potentially Affected Plants - Position 1.2

  • Plant Identification

- 45 operating plants identified in RVID as using Position 1.2

- RVID clearly identifies Position 1.2 as UNIRR_USE_METHOD=65%

- Spot-checking of RVID references to confirm accuracy still TBD

  • Non-conservatism

- Data analysis shows the Position 1.2 estimate to be non-conservative between 13% and 33% of the time

Next Steps NRC

  • Complete technical analysis

- Need NDTT data from Archives to complete assessment of Position 1.1(4)

- Investigate GE RTNDT(u) procedure

- Document findings

  • Complete plant assessment

- Need to assess the impact to Pressure-temperature limits

- Recommend to NRC management regarding use of interim conservatism in defining RTNDT(u) for the plants which may need to update their PTS evaluations

  • Communicate findings to affected plants

- Precise means TBD

  • May need to revise BTP 5-3 in Standard Review Plan Industry
  • Assess the impact of reported potential non-conservatism including the need to redefine the RTNDT(u) on pressure-temperature limits and PTS evaluations

BACKUP SLIDES Comparison of 75 Transverse Charpy Fit Methods 50 NDTT Meas. T50 Trans. T50 RTNDT Non Conservatism Method

[°F] [°F] [°F] [°F] [°F] 25 Charpy Fit Method: tanh (mean) tanh Fit NB-2331 -22 114.5 114.5 54.5 --- Data 1.1(3)a: 0

-22 31 31 -22 76.5 100 Energy*0.65 Charpy Energy [ft-lbs]

1.1(3)b: Longitudinal x 0.65

-22 -15.5 4.5 -22 76.5 T50(LONG)+20 °F 75 Charpy Fit Method: Interpolate lower bound data NB-2331 -22 109.5 109.5 49.5 --- 50 1.1(3)a:

-22 41 41 -19 68.5 Energy*0.65 25 1.1(3)b: tanh Fit

-22 0 20 -22 71.5 Data T50(LONG)+20 °F 0

150 Main Points Longitudinal 125

  • There is some effect of tanh fitting versus lower-bound interpolation 100

- Interpolation can produce higher or 75 lower transition temperature values 50 tanh fit interpolate than tanh fitting lower tanh bound Fit 25 data Data

  • Using either Charpy fitting method, 0 BTP 5-3 Position 1.1(3) is non- -200 -100 0 100 200 300 conservative Temperature [F]

United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of: Entergy Nuclear Operations, Inc.

(Indian Point Nuclear Generating Units 2 and 3)

ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 l 05000286 Exhibit #: NYS000518-00-BD01 Identified: 11/5/2015 NYS000518 Admitted: 11/5/2015 Withdrawn:

Rejected: Stricken:

Submitted: June 9, 2015 Other:

ML14163A524

Assessment of BTP 5-3 Protocols to Estimate RTNDT(u) and USE Mark Kirk Simon Sheng Senior Materials Engineer Senior Materials Engineer RES/DE/CIB NRR/DE/EVIB mark.kirk@nrc.gov simon.sheng@nrc.gov NRC/EPRI Annual Materials Issue Program Information Exchange Meeting 4th June 2014 Rockville, Maryland, USA

Outline of Presentation

  • Un-Irradiated RTNDT (RTNDT(u)) & Un-Irradiated Upper Shelf Energy (USE) definitions & estimates
  • Background of questions concerning BTP 5-3
  • Staff Assessment Part I - Technical evaluation of BTP 5-3 estimation of RTNDT(u) & USE
  • Staff Assessment Part I - Potentially Affected Plants
  • Next steps

Definitions: RTNDT(u) & USE Specimens notched transverse to RD USE average of all energies > 95%

shear per ASTM E185-82 RT NDT(u)= MAX {T NDT , T35 / 50 60}

per ASME NB-2331 Break: Crack No-Break: Fracture completely severs (darkened region) does tension surface of not extend to the sides specimen. of the specimen Temperature NDT is the lowest temperature of no-break performance

RTNDT(u) & USE Estimated by NUREG-0800 BTP 5-3 Approximations Position 1.1(4)

Positions 1.1(1) & 1.1(2)

Position 1.1(3)

RT NDT(u)= MAX {T NDT , T35 / 50 60}

per ASME NB-2331 Position 1.2 USE average of all energies > 95%

shear per ASTM E185-82

Background of Questions Concerning BTP 5-3

  • AREVA Letter (30 Jan 2014, AREVA Ref. NRC:14:004) & PVP Paper (PVP2014-28897) claim Position 1.1(4) of BTP 5.3 is sometimes non-conservative for A508-2 forgings
  • Literature search reveals 1983 EG&G report & 1985 IJPVP paper

- Evaluation of BTP 5-3 (then MTEB 5-2) for NRC

- Conclusions

  • Always conservative

- Position 1.1(1): estimates TNDT

- Position 1.1(2): estimates TNDT

  • Sometime non-conservative

- Position 1.1(3): estimates TCVE(50/35)

- Position 1.1(4): estimates RTNDT

- Position 1.2: estimates USE

Background of Questions Concerning BTP 5-3

  • AREVA Letter (30 Jan 2014, AREVA Ref. NRC:14:004) & PVP Paper (PVP2014-28897) claim Position 1.1(4) of BTP 5.3 is sometimes non-conservative for A508-2 forgings
  • Literature search reveals 1983 EG&G report & 1985 IJPVP paper

- Evaluation of BTP 5-3 (then MTEB 5-2) for NRC

- Conclusions

  • Always conservative

- Position 1.1(1): estimates TNDT

- Position 1.1(2): estimates TNDT

  • Sometime non-conservative

- Position 1.1(3): estimates TCVE(50/35)

- Position 1.1(4): estimates RTNDT

- Position 1.2: estimates USE

NRC Staff Assessment Process Part I: Technical evaluation of BTP Part II: Assessment of 5-3 estimation of RTNDT(u) and USE applicability to plants

  • Data sources
  • Query RVID

- Processed data (T50, USE, ) from - RTNDT(u): establishes BTP 5-3 1983 EG&G report use, but not which position was

- Raw data (CVE, MLE, temp) in used both specimen orientations from - USE: establishes BTP 5-3 use surveillance reports (stored in REAP)

  • Search for documents

- Raw data (NDTT) from RVID refs. referenced by RVID in ADAMS legacy

  • Focus on - Focus on plants closest to PTS

- Plates & forgings only (50.61) limit, these being most

  • No plants have used BTP 5-3 for prone to influence by potential welds non-conservatisms

- Positions identified as sometimes - References establish which non-conservative in 1983 by position of BTP 5-3 was used EG&G report for RTNDT(u)

  • Position 1.1(3): estimates TCVE(50/35)
  • Position 1.1(4): estimates RTNDT
  • Position 1.2: estimates USE

Part I: Technical Evaluation Overview

  • Data sources
  • While similar answers are expected from both sources

- Processed data (T50, USE, )

  • Given the potential impact of this evaluation, going from 1983 EG&G report back to the raw data was seen to be important.

- Raw data (CVE, MLE, temp) 150 A508-2: Heat 527536 from surveillance reports Longitudinal 125 (stored in REAP)

- Raw data (NDTT) from RVID 100 refs. 75 Impact Energy [ft-lbs]

  • Focus on 50 tanh Fit

- Plates & forgings only 25 Data

  • No plants have used BTP 5-3 0 150 for welds Transverse

- Positions identified as 125 sometimes non-conservative 100 by 1983 EG&G report 130°F 47%

  • Position 1.1(3): estimates 75 TCVE(50/35) 50
  • Position 1.1(4): estimates RTNDT 28%

25% tanh Fit

  • Position 1.2: estimates USE 25 43% Data 0

-200 -100 0 100 200 300 Temperature [°F]

Position 1.1(3)

Quotation Tests Required If transversely-oriented Charpy V-notch Longitudinally oriented CVN specimens specimens were not tested, the temperature at which 68 J (50 ft-lbs) and Clear Interpretation 0.89 mm (35 mils) LE would have been Note that this position applies only to conversion between longitudinal obtained on transverse specimens may and transverse Charpy values.

be estimated by one of the following There are two approximations. They may not produce the same criteria: results. They are as follows

- Test results from longitudinally-oriented specimens reduced to 65% of their (a) ETRANS = 0.65xELONG, then calc TC(TRANS) value to provide conservative estimates MLETRANS = 0.65xMLELONG, then calc TC(TRANS-MLE) of values expected from transversely oriented specimens. (b) TC(TRANS) = TC(LONG) + 20 °F

- Temperatures at which 68 J (50 ft-lbs) TC(TRANS-MLE = TC(LONG-MLE) + 20 °F and 0.89 mm (35 mils) LE were obtained on longitudinally-oriented specimens where increased 11 °C (20 °F) to provide a ELONG is CVN energy measured by a longitudinally conservative estimate of the oriented specimen temperature that would have been ETRANS is the estimated CVN for a transversely oriented necessary to obtain the same values on specimen transversely-oriented specimens. TC(LONG) is the temperature at which the minimum of three longitudinal CVN tests exhibits >35 mils AND >50 ft-lbs TC(TRANS) is the estimated temperature at which the minimum of three transverse CVN tests exhibits

>35 mils AND >50 ft-lbs

Position 1.1(3)

Assessing(a): Trans = 0.65xLong

1. Per the BTP, reduce longitudinal measurements to Longitudinal 65% of the measured values Energy
2. Fit Charpy curves

- Energy vs. temperature Transverse =

- Lateral expansion vs. 0.65xLongitudinal temperature Temperature

3. Determine MAX(T50ft-lb, T35mills)
4. Value from Step 3 estimates the transition temperature of transverse data

Position 1.1(3)

Assessing(a): Trans = 0.65xLong Same data plotted two different ways 200 Non-conservative predictons: 33% Plates, 43% Forgings, 36% Overall Non-conservative predictons: 33% Plates, 43% Forgings, 36% Overall 1.0 Transverse T50 Estimate Error [°F]

Plate 0.9 150 Forging 0.8 BTP 5-3 Position 1.1(3) (+20F) 0.7 100 Percentile 0.6 50 Non-conservative 0.5 0.4 0

0.3 Non-conservative 0.2 Plate

-50 Forging 0.1 BTP 5-3 Position 1.1(3) (+20F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Trans T50 est. from Longx0.65 [°F] Transverse T50 Estimate Error [°F]

Position is non-conservative about 36% of the time EG&G Data

Position 1.1(3)

Assessing(a): Trans = 0.65xLong Same data plotted two different ways 200 Non-conservative predictons: 19% Plates, 48% Forgings, 30% Overall 1.0 Non-conservative predictons: 19% Plates, 48% Forgings, 30% Overall Trans. T50ft-lbs&35mills Estimate Error [°F]

Plate 0.9 150 Forging 0.8 BTP 5-3 Position 1.1(3) (0F) 0.7 100 Percentile 0.6 50 Non-conservative 0.5 0.4 0 0.3 Non-conservative 0.2 Plate

-50 Forging 0.1 BTP 5-3 Position 1.1(3) (0F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Trans. T50ft-lbs&35mills est. from Longx0.65 [°F] Transverse T50ft-lbs&35mills estimate error [°F]

T50ft-lbs determines the value of T50ft-lbs&35mills

  • 81% of the time for longitudinal specimens
  • 92% of the time for transverse specimens Position is non-conservative about 30% of the time Raw Data

Position 1.1(3)

Assessing(b): Alternative TC(TRANS) Estimates 250 Mean: T50T = 0.72xT50(e) + 12.5 Bound: T50T = 0.72xT50(e)- 27.5 Plate & Forging 200 Outlier (excluded)

Mean Transverse T50 [°F]

150 Lower Bound 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Trans. T50 from Longx0.65[°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. EG&G Data

Position 1.1(3)

Assessing(a): Alternative TC(TRANS) Estimates 250 Mean: T50&35T = 0.66xT50&35(e) + 13 Bound: T50&35T = 0.66xT50&35(e) - 34 Plate & Forging Transverse T50ft-lbs&35mills [°F]

200 Mean Lower Bound 150 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Trans. T50ft-lb&35mills est. from Longx0.65 [°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. Raw Data

Position 1.1(3)

Assessing(b): TC(TRANS) = TC(LONG) + 20 °F Same data plotted two different ways 200 Non-conservative predictons: 70% Plates, 50% Forgings, 64% Overall 1.0 Non-conservative predictons: 70% Plates, 50% Forgings, 64% Overall Transverse - Longitudinal T50 [°F]

0.9 150 0.8 0.7 100 Percentile 0.6 Non-conservative 50 0.5 0.4 0

0.3 Non-conservative Plate 0.2 Plate

-50 Forging Forging 0.1 BTP 5-3 Position 1.1(3) (+20F) BTP 5-3 Position 1.1(3) (+20F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Longitudinal T50 [°F] Transverse - Longitudinal T50 [°F]

Position is non-conservative about two-thirds of the time EG&G Data

Position 1.1(3)

Assessing(b): TC(TRANS) = TC(LONG) + 20 °F Same data plotted two different ways 200 Non-conservative predictons: 63% Plates, 57% Forgings, 60% Overall 1.0 Non-conservative predictons: 63% Plates, 57% Forgings, 60% Overall 0.9 Trans. - Longl. T50ft-lbs&35mills [°F]

150 0.8 0.7 100 Percentile 0.6 Non-conservative 50 0.5 0.4 0 0.3 Non-conservative Plate 0.2 Plate

-50 Forging Forging 0.1 BTP 5-3 Position 1.1(3) (+20F) BTP 5-3 Position 1.1(3) (+20F)

-100 0.0

-50 -25 0 25 50 75 100 125 -100 -50 0 50 100 150 200 Longitudinal T50ft-lbs&35mills [°F] Transverse - Longitudinal T50ft-lbs&35mills [°F]

T50ft-lbs determines the value of T50ft-lbs&35mills

  • 81% of the time for longitudinal specimens
  • 92% of the time for transverse specimens Position is non-conservative about two-thirds of the time Raw Data

Position 1.1(3)

Assessing(b): Alternative TC(TRANS) Estimates 250 Mean: T50T = 0.58xT50L + 44.7 Lower Bound: T50T = 0.58xT50L + 2.0 Plate & Forging 200 Outlier (excluded)

Mean Transverse T50 [°F]

150 Lower Bound 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Longitudinal T50 [°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. EG&G Data

Position 1.1(3)

Assessing(b): Alternative TC(TRANS) Estimates 250 Mean: T50&35T = 0.68xT50&35L + 35 Low Bound: T50&35T = 0.68xT50&35L - 17 Plate & Forging Transverse T50ft-lbs&35mills [°F]

200 Mean Lower Bound 150 100 50 0

-50

-100

-50 -25 0 25 50 75 100 125 Longitudinal T50ft-lb&35mills [°F]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse T50 values in a manner that is always conservative. Raw Data

Position 1.1(4)

Quotation Tests Required If limited Charpy V-notch tests Limited longitudinally oriented CVN tests at a single temperature were performed at a single temperature to confirm that at Interpretation least 41 J (30 ft-lbs) was obtained, Define: TTEST = the temperature at which limited that temperature may be used as longitudinally oriented CVN tests were an estimate of the RTNDT provided conducted CV = absorbed energy observed at TTEST that at least 61J (45 ft-lbs) was IF CV 45 ft-lbs then RTNDT = TTEST obtained if the specimens were ELSE RTNDT = TTEST + 20 °F longitudinally oriented. If the minimum value obtained was less When assessed using data sets for than 61 J (45 ft-lbs), the RTNDT which full Charpy energy curves are may be estimated as 11 °C (20 °F) available, EG&G interpreted Position above the test temperature. 1.1(4) as having 2 possible meanings:

- RTNDT = T45(LONG), and

- RTNDT = T30(LONG) + 20 °F These might not produce the same result. Therefore, both were assessed.

Position 1.1(4)

Assessed for Forgings RTNDT = T30(LONG) + 20 °F RTNDT = T45(LONG) 150 SA-508-2 Forging. RTndt per BTP 5-3 1.1(4) 150 SA-508-2 Forging. RTndt per BTP 5-3 1.1(4)

Estimated RTNDT = T30L+20 [°F]

Estimated RTNDT = T45L [°F]

100 Forging 100 SA-508-2 50 50 Top &

0 0 bottom panel of

-50 -50

-100 -100

-150 Non-Conservative

-150 Non-Conservative each pair

-150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 -150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 are the 1.0 0.9 93% of data under-predicted. Max =-95F 1.0 0.9 93% of data under-predicted. Max =-86F same data 0.8 0.7 0.8 0.7 plotted two different Percentile Percentile 0.6 0.6 Non-Conservative Non-Conservative 0.5 0.5 0.4 0.3 0.4 0.3 ways 0.2 0.2 0.1 0.1 0.0 0.0

-100 -50 0 50 100 150 200 -100 -50 0 50 100 150 200 Error in Estimated RTNDT [°F] Error in Estimated RTNDT [°F]

Position is non-conservative about 90% of the time EG&G Data

Position 1.1(4)

Assessed for Plates RTNDT = T30(LONG) + 20 °F RTNDT = T45(LONG) 150 SA-533B-1 Plate. RTndt per BTP 5-3 1.1(4) 150 SA-533B-1 Plate. RTndt per BTP 5-3 1.1(4)

Estimated RTNDT = T30L+20 [°F]

Estimated RTNDT = T45L [°F]

100 Plate 100 SA-533B-1 50 50 Top &

0 0 bottom

-50 -50 panel of

-100 -100

-150 Non-Conservative

-150 Non-Conservative each pair

-150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 -150 -100 -50 "Official" RTNDT per ASME NB-2331 [°F]

0 50 100 are the 1.0 0.9 38% of data under-predicted. Max =-38F 1.0 0.9 38% of data under-predicted. Max =-27F same data Non-Conservative Non-Conservative 0.8 0.7 0.8 0.7 plotted 2 different Percentile Percentile 0.6 0.6 0.5 0.5 0.4 0.3 0.4 0.3 ways 0.2 0.2 0.1 0.1 0.0 0.0

-100 -50 0 50 100 150 200 -100 -50 0 50 100 150 200 Error in Estimated RTNDT [°F] Error in Estimated RTNDT [°F]

Position is non-conservative about 40% of the time EG&G Data

Position 1.2 Quotation Tests Required For the beltline region of reactor vessels, Longitudinally oriented CVN specimens tested on the upper shelf.

the upper shelf toughness must account for the effects of neutron radiation. Clear Interpretation Reactor vessel beltline materials must USETRANS = 0.65 x USELONG have Charpy upper shelf energy, in the where transverse direction for base material and along the weld for weld material USELONG is CVN energy measured by longitudinally oriented specimens on according to the ASME Code, of no less the upper shelf than 102 J (75 ft-lbs) initially and must USETRANS is the estimated CVN energy for maintain Charpy upper shelf energy transversely oriented specimens on the upper shelf throughout the life of the vessel of no less than 68 J (50 ft-lbs).

If Charpy upper shelf energy values were not obtained, conservative estimates should be made using results of tests on specimens from the first surveillance capsule removed.

If tests were only made on longitudinal specimens, the values should be reduced to 65% of the longitudinal values to estimate the transverse properties.

Position 1.2 Assessing: USETRANS = 0.65 x USELONG Same data plotted two different ways Non-conservative predictons: 20% Plates, 14% Forgings, 18% Overall 1.0 Non-conservative predictons: 20% Plates, 14% Forgings, 18% Overall 1.4 Transverse / Longitudinal USE Ratio 0.9 1.2 Plate 0.8 Forging 1.0 0.7 BTP 5-3 Position 1.2 (0.65)

Percentile 0.6 0.8 0.5 0.6 0.4 Non-conservative 0.3 0.4 Plate Non-conservative 0.2 0.2 Forging 0.1 BTP 5-3 Position 1.2 (0.65) 0.0 0.0 0 50 100 150 200 250 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Longitudinal Upper Shelf Energy [ft-lbs] Transverse / Longitudinal USE Ratio Position is non-conservative about 18% of the time EG&G Data

Position 1.2 Assessing: USETRANS = 0.65 x USELONG Same data plotted two different ways Non-conservative predictons: 13% Plates, 33% Forgings, 21% Overall 1.0 Non-conservative predictons: 13% Plates, 33% Forgings, 21% Overall 1.4 Transverse / Longitudinal USE Ratio 0.9 1.2 Plate 0.8 Forging 1.0 0.7 BTP 5-3 Position 1.2 (0.65)

Percentile 0.6 0.8 0.5 0.6 0.4 Non-conservative 0.3 0.4 Plate Non-conservative 0.2 0.2 Forging 0.1 BTP 5-3 Position 1.2 (0.65) 0.0 0.0 0 50 100 150 200 250 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Longitudinal Upper Shelf Energy [ft-lbs] Transverse / Longitudinal USE Ratio Position is non-conservative about 21% of the time Raw Data

Position 1.2 Assessing: Alternative USETRANS Estimates 250 Mean: Tuse = 0.61xLuse + 21.2 Lower Bound: Tuse = 0.61xLuse - 22.1 Transverse Upper Shelf Energy [ft-lb]

200 Plate Forging 150 Mean Lower Bound 100 50 0

0 50 100 150 200 250 Longitudinal Upper Shelf Energy [ft-lb]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse USE values in a manner that is always conservative. EG&G Data

Position 1.2 Assessing: Alternative USETRANS Estimates 250 Mean: Tuse = Luse - 36 Lower Bound: Tuse = Luse - 65 Transverse Upper Shelf Energy [ft-lb]

200 Plate Forging 150 Mean Lower Bound 100 50 0

0 50 100 150 200 250 Longitudinal Upper Shelf Energy [ft-lb]

Preliminary analysis suggests that alternative formulae could be developed to convert longitudinal to transverse USE values in a manner that is always conservative. Raw Data

Summary on Part I - Technical Evaluation

  • Positions 1.1(3) and 1.2

- Results of the two studies are similar

- Staff analysis confirms non-conservatism

  • Position 1.1(4)

- EG&G report demonstrates position is non-conservative

- Awaiting NDTT data from Archives to complete staff assessment Forging Non-Conservative Plate Non-Conservative Position of BPT 5-3 Prediction Rate Prediction Rate EG&G Data Raw Data EG&G Data Raw Data (a) TRANS = 0.65xLONG 43% 48% 33% 19%

1.1(3)

(b) TC(TRANS) = TC(LONG) + 20 °F 50% 57% 70% 63%

RTNDT = T45(LONG) 93% TBD 38% TBD 1.1(4)

RTNDT = T30(LONG) + 20 °F 93% TBD 38% TBD 1.2 USETRANS = 0.65 x USELONG 14% 33% 20% 13%

Part II: Assess Potentially Affected Plants - Position 1.1(3)

Plant Identification

  • Search RVID for plants using BTP 5-3 to determine plate (forging) RTNDT(u):

20 operating plants

  • Rank plates (forging) according to the difference between RTPTS at 32 EFPY and 270 °F:

Eight plants have their limiting plates or forgings using BTP5-3 with difference less than 100 °F.

Plant-specific evaluation results

  • The majority of the plants did not specify which BTP 5-3 B1.1 position was used in determining their RTNDT(u) values
  • Details of calculation of RTNDT(u) values are not available.
  • One plant has full transverse Charpy data and the staff confirmed that BTP 5-3 was not used , so it will be dropped from the list
  • A few plants have full longitudinal Charpy data

- The staffs RTNDT(u) values using lower bound Charpy data and linear interpolation between two temperatures are lower than the licensees value by 10 °F

  • A few plants may have PTS concern because the RTPTS values are below 270 °F by less than 75 °F

- In one case, the longitudinal Charpy data for one plate are significantly higher than other plates, indicating potential mislabeling

Why do we use the Selecting criterion of 75 °F?

- Identify raw data with the greatest conservatism and non-conservatism Wattss Bar 1 - greatest non-conservatism Millstone 2 - greatest conservatism 200 Non-conservative predictons: 63% Plates, 57% Forgings, 60% Overall Trans. - Longl. T50ft-lbs&35mills [°F]

150 Watts Bar 1 100 Non-conservative 50 0

Plate

-50 Forging BTP 5-3 Position 1.1(3) (+20F)

-100

-50 -25 0 25 50 75 100 125 Longitudinal T50ft-lbs&35mills [°F]

Closer Look at the Charpy Data with the Greatest Non-Conservatism 150 150 125 125 Impact Energy [ft-lbs] Impact Energy [ft-lbs]

100 100 75 75 50 50 tanh Fit 25 25 tanh Fit Data Data 0 0

-200 -100 0 100 200 300 -200 -100 0 100 200 300 Temperature [F] Temperature [F]

T50flb T35mill T50flb T35mill T50flb T35mill

[oF] [oF] [oF] [oF] [oF] [oF]

114.5 83.0 31 - -15.5 -9.4 Transverse Data Longitudinal Data X .65 Longitudinal Data

Determine the RTNDT for the Raw Data with the Greatest Non-Conservatism

  • Nil-ductility transition temperature (NDTT): -22 °F
  • Official RTNDT(u) value: = 54.5 °F (114.5 °F - 60 °F)
  • RTNDT(u) based on BTP 5-3B1.1(3)a: -22 °F (At 31 °F, the equivalent Charpy energy (.65 x longitudinal data) is 50 ft-lb; RTNDT = NDTT)
  • RTNDT(u) based on BTP 5-3B1.1(3)b: -22 °F (At -15.5 °F, the Charpy energy is 50 ft-lb; since the adjusted temp is (-15.5 °F + 20 °F ), less than (-22°F +

60 °F), RTNDT = NDTT)

Summary on the Study Focusing on the Raw Data with the Highest Non-Conservatism

  • The highest non-conservative raw data is about 75 °F
  • RTNDT determination is not sensitive to whether B1.1(3)a or B1.1(3)b is used for this case
  • RTNDT determination is affected by whether curve fitting of the entire Charpy data or hand calculations based on Charpy data at two temperatures are used

Part II: Assess Potentially Affected Plants - Position 1.2

  • Plant Identification

- 45 operating plants identified in RVID as using Position 1.2

- RVID clearly identifies Position 1.2 as UNIRR_USE_METHOD=65%

- Spot-checking of RVID references to confirm accuracy still TBD

  • Non-conservatism

- Data analysis shows the Position 1.2 estimate to be non-conservative between 13% and 33% of the time

Next Steps NRC

  • Complete technical analysis

- Need NDTT data from Archives to complete assessment of Position 1.1(4)

- Investigate GE RTNDT(u) procedure

- Document findings

  • Complete plant assessment

- Need to assess the impact to Pressure-temperature limits

- Recommend to NRC management regarding use of interim conservatism in defining RTNDT(u) for the plants which may need to update their PTS evaluations

  • Communicate findings to affected plants

- Precise means TBD

  • May need to revise BTP 5-3 in Standard Review Plan Industry
  • Assess the impact of reported potential non-conservatism including the need to redefine the RTNDT(u) on pressure-temperature limits and PTS evaluations

BACKUP SLIDES Comparison of 75 Transverse Charpy Fit Methods 50 NDTT Meas. T50 Trans. T50 RTNDT Non Conservatism Method

[°F] [°F] [°F] [°F] [°F] 25 Charpy Fit Method: tanh (mean) tanh Fit NB-2331 -22 114.5 114.5 54.5 --- Data 1.1(3)a: 0

-22 31 31 -22 76.5 100 Energy*0.65 Charpy Energy [ft-lbs]

1.1(3)b: Longitudinal x 0.65

-22 -15.5 4.5 -22 76.5 T50(LONG)+20 °F 75 Charpy Fit Method: Interpolate lower bound data NB-2331 -22 109.5 109.5 49.5 --- 50 1.1(3)a:

-22 41 41 -19 68.5 Energy*0.65 25 1.1(3)b: tanh Fit

-22 0 20 -22 71.5 Data T50(LONG)+20 °F 0

150 Main Points Longitudinal 125

  • There is some effect of tanh fitting versus lower-bound interpolation 100

- Interpolation can produce higher or 75 lower transition temperature values 50 tanh fit interpolate than tanh fitting lower tanh bound Fit 25 data Data

  • Using either Charpy fitting method, 0 BTP 5-3 Position 1.1(3) is non- -200 -100 0 100 200 300 conservative Temperature [F]
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