L-MT-12-108, Responses to Request for Additional Information for Trace/Tracg Differences - Maximum Extended Load Line Limit Analysis Plus License Amendment Request

Responses to Request for Additional Information for Trace/Tracg Differences - Maximum Extended Load Line Limit Analysis Plus License Amendment Request

ML13002A261
Person / Time
Site:	Monticello
Issue date:	12/21/2012
From:	Schimmel M Xcel Energy, Northern States Power Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-MT-12-108, TAC ME3145
Download: ML13002A261 (37)

Text

ENCLOSURES 2 AND 5 CONTAIN PROPRIETARY INFORMATION WITHHOLD FROM PUBLIC DISCLOSURE IN ACCORDANCE WITH 10 CFR 2.390 SXcelEnergy~ Monticello Nuclear Generating Plant 2807 W County Rd 75 Monticello, MN 55362 December 21, 2012 L-MT-12-108 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket 50-263 Renewed License No. DPR-22

Subject:

Maximum Extended Load Line Limit Analysis Plus License Amendment Request - Request for Additional Information Responses for TRACE/TRACG Differences (TAC ME3145)

References:

1) Letter from T J O'Connor (NSPM), to Document Control Desk (NRC),

"License Amendment Request: Maximum Extended Load Line Limit Analysis Plus," L-MT-10-003, dated January 21, 2010. (ADAMS Accession No. ML100280558)

2) Email from T Beltz (NRC) to J Fields (NSPM), et al, "Monticello Nuclear Generating Plant - Draft Request for Additional Information re: MELLLA+ License Amendment Review (TAC No. ME3145),"

dated October 4, 2012. (ADAMS Accession No. ML12279A224)

3) Email from T Beltz (NRC) to J Fields (NSPM), et al, "Monticello Nuclear Generating Plant - Draft Requests for Additional Information re: MELLLA+ License Amendment Request Review (TAC No.

ME3145) - Revision 1," dated November 8, 2012. (ADAMS Accession No. ML12319A179)

In Reference 1, Northern States Power Company, a Minnesota corporation (NSPM),

doing business as Xcel Energy, requested approval of an amendment to the Monticello Nuclear Generating Plant (MNGP) Renewed Operating License (OL) and Technical Specifications (TS). The proposed change would allow operation in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+) domain.

In Reference 2 the NRC provided a series of Requests for Additional Information (RAIs) pertaining to differences the NRC identified between TRACE and TRACG codes related

Document Control Desk Page 2 to the transition to stable film boiling (the "Tmin correlation") and the quenching methodology.

On October 16, 2012 the NRC held a conference call with NSPM and General Electric -

Hitachi (GEH) concerning the RAIs provided in Reference 2. During the conference call GEH described several published reports available in the public domain that addressed many of the questions the NRC had related to these correlations. Subsequently, NSPM provided at the NRC's request, the discussed published reports.

Based on these responses, the NRC held an audit of GEH (on October 24 - 25, 2012) where further discussions were held regarding the application of these methods in the TRACG and TRACE codes.

Upon completion of the audit, the NRC issued new RAIs in Reference 3 to complete their documentation needs. The RAIs provided in Reference 3 include NRC requests for augmented information relative to the Tmin correlation and the quenching methodology. to the letter provides the responses to the RAIs provided in Reference 2.

Specific technical documents cited in the response were provided to the NRC via email as these documents are available in the public domain. These technical documents are not reproduced in Enclosure 1. The responses to Reference 2 are non-proprietary. to the letter provides the responses to the RAIs provided in Reference 3.

These responses contain proprietary information to GEH. The response to RAI No. 5 provides a revised peak clad temperature (PCT) value for the anticipated transients without scram with instability (ATWSI) event that exceeds the PCT value previously provided to the NRC in Reference 1. The result in RAI No. 5, case No.3 represents the revised bounding PCT value for the ATWSI event under MELLLA+ conditions. to the letter provides a non-proprietary version of the responses to the RAIs provided in Reference 3. The non-proprietary version of the RAI responses is being provided based on the NRC's expectation that the submitter of the proprietary information should provide, if possible, a non-proprietary version of the document with brackets showing where the proprietary information has been deleted. contains an affidavit executed to support withholding Enclosures 2 and 5 from public disclosure. Enclosures 2 and 5 contain proprietary information as defined by 10 CFR 2.390. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the NRC and addresses with specificity the considerations listed in 10 CFR 2.390(b)(4). Accordingly, NSPM respectfully requests that the proprietary information in Enclosures 2 and 5 be withheld from public disclosure in accordance with 10 CFR 2.390(a)4, as authorized by 10 CFR 9.17(a)4.

Correspondence with respect to the copyright or proprietary aspects of GEH information or the supporting GEH affidavit in Enclosure 4 should be addressed to Francis T.

Document Control Desk Page 3 Bolger, Manager, New Product Introduction, GE Hitachi Nuclear Energy, 3901 Castle Hayne Road, Wilmington, NC 28401. provides a compact disc (CD), entitled "GE-MNGP-AEP-3223, Enclosure 2" containing data requested by the NRC to support responses to RAI 4 in Enclosure 2.

The entire contents of the CD are considered proprietary information. As such this information is also covered by the affidavit provided by GEH in Enclosure 4.

This letter makes no new commitments and no revisions to existing commitments. I declare under penalty of perjury that the foregoing is true and correct.

Executed on: December_, 2012 Mark A. Schimmel Site Vice-President Monticello Nuclear Generating Plant Northern States Power Company-Minnesota Enclosures (5) cc: Regional Administrator, Region III, USNRC (w/o enclosures)

Project Manager, Monticello Nuclear Generating Plant, USNRC Resident Inspector, Monticello Nuclear Generating Plant, USNRC (w/o enclosures)

Minnesota Department of Commerce (w/o enclosures)

L-MT-12-108 ENCLOSURE I RESPONSES TO NRC REQUEST FOR ADDITIONAL INFORMATION DATED OCTOBER 4,2012 5 pages follow

GE-MNGP-AEP-3217 Non-Proprietary Information - Class I (Public) Page 1 of 5 REQUEST FOR ADDITIONAL INFORMATION RELATING TO MONTICELLO LICENSING AMENDMENT REQUEST FOR MAXIMUM LOAD LINE LIMIT ANALYSIS PLUS NORTHERN STATES POWER COMPANY - MINNESOTA MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263 The NRC staff has performed a series of confirmatory calculations for ATWSI (anticipated transients without scram with instability) using the TRACE/PARCS code. These calculations have identified difference between TRACE and TRACG related to the transition to stable film boiling (the "Tmin correlation").

TRACE uses a Tmin correlation that predicts significantly lower temperatures for stable film boiling than the correlation used by TRACG. The impact is significant, because the TRACE confirmatory calculations for a generic BWR5 showed failure to rewet followed by fuel failure (Tclad >2200'F), while the TRACG calculations show clad rewet and that fuel integrity is maintained.

The NRC staff needs to review, in more detail, the available data supporting the applicability of the TRACG correlation. Of special interest is the range of applicability. These correlations were developed primarily to support LOCA conditions, where the power generation is minimal (decay heat) and the pressure is low. The staff needs to ensure that the correlation is applicable to power conditions at full pressure. Emphasis must be provided on the availability of data and its range of applicability.

In addition to the Tmin correlation issue, the NRC staffs confirmatory calculations uncovered a second methodology difference related to the quenching of the vapor film after it forms. The quenching mechanism is by removing heat through axial conduction when the thermal hydraulic conditions of the coolant allow it (e.g., in the down side of the power-flow oscillations). The TRACE quenching model predicts that quenching essentially does not occur while the rods are at power and the vapor film remains stable during the oscillations. The TRACG quenching model, however, predicts that there is sufficient heat conducted axially through the clad to lower the surface temperature, thus eliminating the stable vapor film and increasing the heat transfer.

As with the Tmin correlation issue, the NRC staff needs to review the available benchmark data to validate the TRACG quenching models, and the range of applicability of this data.

GE-MNGP-AEP-3217 Non-Proprietary Information - Class I (Public) Page 2 of 5 Based on the results of the NRC staffs confirmatory analyses, areas of concern were identified that require clarification by the Monticello Nuclear Generating Plant licensee.

1. Provide a short description of the GEH Tmin and quenching methodology. Specifically,

a. What correlations are used?

b. What options can be used (e.g., void dependencies...)?

c. How the quenching is modeled?

2. Tmin benchmark data

a. What experimental data supports the Tmin correlation?

b. What is the range of applicability?

3. Quenching benchmark data

a. What experimental data supports the methodology?

b. Any previous work in the open literature?

c. What is the range of applicability?

GE-MNGP-AEP-3217 Non-Proprietary Information - Class I (Public) Page 3 of 5 NRC Question

1. Provide a short description of the GEH Tmin and quenching methodology. Specifically,

a. What correlations are used?

GEH Response The Shumway correlation for the minimum film boiling temperature is used and is documented in NEDE-32176P, Revision 4, Section 6.6.7. See also the discussion of this model in NEDE-32906P Supplement 3-A, Revision 1, Section 4.1, and in Section 3.7 of the embedded NRC safety evaluation.

The axial conduction quenching model is documented in NEDE-32176P, Revision 4, Section 6.6.13. See also the discussion of this model in NEDE-32906P Supplement 3-A, Revision 1, Section 4.1, and in Section 3.5 of the embedded NRC safety evaluation. The model is adopted from the approved SAFER/CORCL LOCA model NEDE-30996P-A, Volume 1, Section 5.2.6.4.

NRC Question

b. What options can be used (e.g., void dependencies...)?

GEH Response There is an option in TRACG04 to use either the homogeneous nucleation model, the maximum of the homogeneous nucleation model and the Iloeje correlation, or the Shumway correlation for Tmin. The Shumway correlation is the recommended model in the TRACG04 User's Manual.

GEH has furthermore implemented an option in the Shumway correlation to disable the void fraction dependence due to the limited qualification of this dependence.

NRC Question

c. How the quenching is modeled?

GEH Response Quenching when the wall temperature drops below the minimum film boiling temperature is modeled with the transition boiling model, which is documented in NEDE-32176P, Revision 4, Section 6.6.8.

Quench front propagation is implemented by adding the heat transfer due to axial conduction as calculated from the correlation to the heat balance for the node containing a quench front.

GE-MNGP-AEP-3217 Non-Proprietary Information - Class I (Public) Page 4 of 5 NRC Question

2. Tmin benchmark data

a. What experimental data supports the Tmin correlation?

GEH Response The experimental data supporting the Shumway correlation are documented in EGG-RST-6781.

NRC Question

b. What is the range of applicability?

GEH Response The range of applicability for the Shumway correlation is documented in EGG-RST-6781. This includes pressures from 0.4 - 6.9 MPa and Reynolds numbers from 0.1 - 7.0E5. ORNL data reported in EGG-RST-6781 contained data up to 9 MPa, but were not used in the determination of the mean bias and standard deviation for the Shumway correlation due to uncertainty in the exact pressure for the data points.

GE-MNGP-AEP-3217 Non-Proprietary Information - Class I (Public) Page 5 of 5 NRC Question

3. Quenching benchmark data

a. What experimental data supports the methodology?

GEH Response The experimental data supporting the axial conduction controlled quenching model is documented in NEDE-30996P-A, Volume 1, Section 5.2.6.4.

Qualification of the rewetting model has been done primarily through transient flow oscillation tests at normal reactor operational pressure such as the tests documented in NEDE-32177P, Revision 3, Section 3.6.1, core spray heat transfer tests such as the tests documented in NEDE-32177P, Revision 3, Section 3.2.2, and Integral LOCA simulation tests such as the tests documented in NEDE-32177P, Revision 3, Sections 5.1 through 5.6.

NRC Question

b. Any previous work in the open literature?

GEH Response Numerous references from the open literature supporting the Shumway minimum film boiling correlation are documented in EGG-RST-6781. There are many references for axial conduction controlled quenching in the open literature including:

" Yamanouchi, "Effect of core spray cooling in transient state after loss of coolant accident", Journal of Nuclear Science and technology 5(11), p. 547-558, 1969.

• T. S. Thompson, "On the process of rewetting a hot surface by a falling liquid film",

Nuclear Engineering and Design 31(1974) 234-245.

" K. H. Sun, G. E. Dix and C. L. Tien, "Effect of precursory cooling on falling-film rewetting", Journal of Heat Transfer, 1975.

NRC Question

c. What is the range of applicability?

GEH Response The axial conduction controlled quenching model was developed in the 1970s in support of LOCA applications and is based primarily on reflood data and top down quenching by falling liquid films at low pressure.

L-MT-12-108 ENCLOSURE 3 RESPONSES TO NRC REQUEST FOR ADDITIONAL INFORMATION DATED NOVEMBER 8, 2012 - NON-PROPRIETARY 23 pages follow

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 1 of 23 REQUEST FOR ADDITIONAL INFORMATION RELATING TO THE LICENSE AMENDMENT REQUEST FOR MAXIMUM LOAD LINE LIMIT ANALYSIS PLUS (MELLLA+)

NORTHERN STATES POWER COMPANY - MINNESOTA (NSPM)

MONTICELLO NUCLEAR GENERATING PLANT (MNGP)

DOCKET NO. 50-263 TAC NO. ME3145 On October 24-25, 2012, the U.S. Nuclear Regulatory Commission (NRC) staff performed an audit at GE-Hitachi Nuclear Americas (GEH) with respect to Tmin and quenching methodologies, and identified that additional information is needed for the staff to complete its review of the MNGP MELLLA+

license amendment request. The requests for additional information are provided below.

RAI 1

For a typical quench front calculated by TRACG04 for representative ATWSI [anticipated transients without scram with instability] conditions, provide the heat rate to the liquid and vapor state and the quench component of the heat rate. Compare with the measured heat rate values published by Thompson in NED 1974, "On the Process of Rewetting a Hot Surface by a Falling Liquid."

RAI 2

Provide a detailed description of the TRACG implementation of the quench front model.

Provide a numerical comparison of the heat transfer coefficients used by TRACG downstream of the front and "normal" coefficients in nucleate boiling.

RAI 3

Generate TRACG quench model inputs for a number of Halden dryout experiments and provide a comparison of the results to validate the quench front velocity model at high power and pressures.

RAI 4

Provide the TRACG input decks for the Halden experiments including the digitized data from the experiments used to compare the results. In addition, please provide the TRACG output file and CEDAR file (in ascii if possible).

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 2 of 23

RAI 5

Reproduce the ATWSI calculations for MNGP with and without applying the void and the Zr credit in the Shumway Tmin correlation using the latest version of the TRACG code.

Provide a comparison of results.

Provide a plot that shows the hot rod clad temperature on the same plot as the calculated Tmin as function of time.

Provide a comparison for the variables shown in Figs 9-12 through 9-14 of NEDC-33435P, Revision 1.

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 3 of 23 NRC RAI 1 For a typical quench front calculated by TRACG04 for representative ATWSI [anticipated transients without scram with instability] conditions, provide the heat rate to the liquid and vapor state and the quench component of the heat rate. Compare with the measured heat rate values published by Thompson in NED 1974, "On the Process of Rewetting a Hot Surface by a Falling Liquid."

GEH Response The requested plots are provided based on Halden Experiment 4 TRACG run from RAI 3 (See Figure 3-3). Figure 1-1 shows the heat rate to the liquid and vapor and the quench heat rate for heated Node 36 (Location of the upper temperature measurement). ((

The T. S. Thompson paper, listed in the RAI, evaluates the heat transfer at the quench front. Note that the paper used in this RAI (Reference 1-1) is the paper noted on the footnote on page one of the T. S. Thompson paper listed in the RAI, as a better copy of the reference paper was available.

Figures 13 and 14 show the heat flux in the vicinity of the interface (quench front) for variations in pressure and downstream temperature. This shows that the quench front is a "high-heat-flux zone" with heat flux as high as 30 times the liquid heat flux just 0.12 inches (0.3 cm) from the quench front.

The TRACG quench model predicts ((

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 4 of 23 Figure 1-1 Quench Heat Rate - Node 13 References 1-1. T. S. Thompson, AECL-4516, "On the Process of Rewetting a Hot Surface By a Falling Liquid Film," Atomic Energy of Canada Limited, June 1973.

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 5 of 23 NRC RAI 2 Provide a detailed description of the TRACG implementation of the quench front model.

Provide a numerical comparison of the heat transfer coefficients used by TRACG downstream of the front and "normal" coefficients in nucleate boiling.

GEH Response TRACG Quench Front Model Implementation The TRACG model for the axial conduction controlled quench front propagation is documented in the TRACG Model Description (Reference 2-1) Section 6.6.13. It simulates the one- and two-dimensional solutions of References 2-2 and 2-3 and was retained from TRAC-P1A (References 2-4, 2-5, 2-6), which was the starting point for the development of the BWR versions of TRAC and TRACG. The model is based on a solution of the two-dimensional heat conduction in the cladding around the quench front location. Figure 2-1 is an illustration of the temperature profile and heat conduction at a quench front.

ma *#*r00 OCA"041.

Pl~rwgnvw c C010UCT10 I Rr Ir _ Quench Front

] Velocity: v.

tut"1Ac TlMKA0MLW Figure 2-1. Axial Conduction Controlled Quenching Ahead of or downstream of the quench front the wall is in film boiling at a high temperature Tw+ , the wall surface temperature is equal to the quench front temperature To at the quench front, and behind or upstream of the quench front, the wall temperature quickly approaches the saturation temperature.

Heat is conducted axially in the wall due to the temperature gradient from the downstream to the upstream region, and outwards to the liquid in the upstream region. The quench front model

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 6 of 23 correlates the total heat transfer to the liquid upstream of the quench front due to this heat transfer at the quench front. The total heat transfer per unit perimeter to the fluid behind quench front due to the two dimensional heat conduction in the cladding, axially from the dry to the quenched regions and radially to the fluid in the in the quenched region, is given by Equation 2-1.

- Tsar ) (1+0.4B q =kw(T,+,, 5 (2-1)

In this equation the modified Biot number Bi is given by Equations 6.6-153 - 6.6-156 in the TRACG Model Description (Reference 2-1).

For conditions where the energy generation in the fuel rod is small, ((

)), and the quench front propagation velocity Vq is given by:

qq=VqPwCpwd. (TW ~T.a) (2-3)

Combining Equations 2-1 and 2-3 gives:

_ kw (-B (1+O.4_Bii)o. (2-4)

VqPwCpwdw which is identical to Equation 6.6-152 in Reference 2-1.

Equation 2-3 together with measured quench front propagation velocities for conditions where the energy generation rate is small have been used to correlate the quench front temperature TO and the heat transfer coefficient hq immediately behind the quench front. These values are documented in Reference 2-1.

Heat Transfer Coefficients for Halden Test 4 Halden Test 4 (Reference 2-7) is used to illustrate the heat transfer coefficients around the quench front. ((

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 7 of 23

)). The heat transfer coefficients in the upstream and downstream of the quench front are shown in Table 2-1.

Table 2-1. Heat Transfer Coefficients in the Upstream and Downstream of the Quench Front for Halden Test 4 at t = 62.1 sec.

Node Heat Transfer Coefficient, WIm 2 -K' 32 [] Upstream 33 (( ]

34 [

35 [

36 [] Quench Front Location 37 Downstream 38

)). This heat transfer coefficient' hq, which is used in the Biot Number given by Equation 6.6-154 of Reference 2-1, is calculated by Equation 2-5 which has been retained fromTRAC-P1A and TRAC-BD1 (References 2-4, 2-5, 2-8),

1 In the preparation of this response to this RAI, an error in Equation 6.6-158 of Reference 2-1 was discovered. Equation 2-5 is consistent with the coding in TRACG04 and the original coding from TRAC-PlA. Equation 6.6-158 will be corrected in the next revision of Reference 2-1

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 8 of 23 which also employed Equation 2-1 for the calculation of the quench front propagation, and it is based on FLECHT reflood data:

f4.2.10 0.5I(o ---Tsat)-

Vr"9921(To UqVr 10 0 616 T )-1.48. for vr > 0.0092 ,(2-5)

L 1 .81 0v 56 .- T for vr < 0.0092 where Vr is the reflood velocity obtained from the liquid velocity upstream of the quench front. The high value of the quench front heat transfer coefficient is consistent with the observations in Reference 2-9. These models for the quench front heat transfer coefficient and the total quench front heat transfer have been used in the qualification against the Halden Tests as documented in the response to RAI 3.

References 2-1 "TRACG Model Description," NEDE 32176P, Revision 4, January 2008.

2-2 F. D. Shum et. al., "SAFER Model for Evaluation of Loss-of-Coolant Accidents for Jet Pump and Non-Jet Pump Plants," NEDE-30996P-A, GE Proprietary Report, October 1987.

2-3 C. L. Tien and L. S. Yao, "Analysis of Conduction-Controlled Rewetting of a Vertical Surface," Journal of Heat Transfer, May 1975, pp. 161-165.

2-4 "TRAC-P1A: An Advanced Best-Estimate Computer Program for PWR LOCA Analysis,"

NUREG/CR-0665, Los Alamos Scientific Laboratory, May 1979.

2-5 "TRAC-BDI: An Advanced Best-Estimate Computer Program for Boiling Reactor Loss-of-Coolant Accident Analysis," NUREG/CR-2178, October 1981.

2-6 S. S. Dua and C. L. Tien, "A generalized Two-Parameter Relation for Conduction Controlled Rewetting of a Hot Vertical Surface," International Journal of Heat and Mass Transfer, Vol. 20, pp. 174-176, 1977.

2-7 R. laniri, "The Third Dryout Fuel behavior Test Series in IFA-613," HWR-552, February 1998.

2-8 S. K. W. Yu, P. R. Farmer and M. W. Coney, "Methods and Correlations for the Prediction of Quenching Rates on Hot Surfaces," International Journal of Multiphase Flow, 3, 1977, pp. 415-443.

2-9 T. S. Thompson, "On the Process of rewetting a Hot Surface by a Falling Liquid Film,"

Nuclear Engineering and Design 31, 1974, pp. 234-245.

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 9 of 23 NRC RAI 3 Generate TRACG quench model inputs for a number of Halden dryout experiments and provide a comparison of the results to validate the quench front velocity model at high power and pressures.

GEH Response TRACG input models were created to augment the validation basis of the TRACG quench front heat transfer model by simulating a few Halden Third-Series experiments (Reference 3-1). They are performed with actual fuel rods with Zircaloy cladding, at high power, and at high pressure (around 7 MPa). In addition, quenching is observed at temperatures above TRACG-calculated Tmin.

The four Halden experiments that resulted in quenching from elevated temperature (>650 *C) are simulated with TRACG. They are experiments 3, 4, 1 lc, and 12. Unless noted otherwise, all TRACG cases are performed with the quench model on and with the modified (no void term) Shumway correlation for Tmin. The Shumway correlation is documented in Reference 3-2.

Experiment 3 The flow input and PCT result are shown in Figures 3-1 and 3-2. The results show that the TRACG quenching occurs similar to the test. The timing of the start of boiling transition is delayed compared to the test, but this can be expected given test measurement uncertainty (power, flow, temperature, etc.). However, to assess the quench at the higher test temperatures, ((

)) The results show good agreement in the quench.

Experiment 4 The flow input and PCT result are shown in Figure 3-3 and 3-4. The results show that the TRACG quenching occurs similar to the test.

((I Several cases were performed to assess the effect of turning off the TRACG quench model and lowering the Tmrin compared to the modified Shumway Tmin. Trin is lowered by multiplying (Tmin - Tsat) by 0.69, an estimated factor that accounts for Inconel wall properties rather than zircaloy. Figure 3-7 shows the PCT results. ((

)) This shows the importance of using the TRACG quench model which predicts the experimental data very well.

Experiment 11 c Experiment 11 involved a series of 6 dryout tests. Rather than attempt to model the series, only the dryout that resulted in the highest temperature is assessed. This portion of the test occurred between 900 and 1000 seconds and is called Test 1lc.

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 10 of 23

((I

)) The TRACG flow rate input is estimated to result in similar PCT heatup.

The flow input and PCT result are shown in Figures 3-8 and 3-9. The results show that the TRACG quenching occurs similar to the test.

Experiment 12 The flow input and PCT result are shown in Figures 3-10 and 3-11.

)) the TRACG flow rate input is estimated to result in similar PCT heatup. The results show that the TRACG quenching occurs similar to the test.

To show the strong sensitivity of flow on the results and ((

)) Figure 3-11 shows the assumed flow rates that resulted in the PCTs in Figure 3-10. ((

))

Several cases were performed to assess the effect of turning off the quench model and lowering Tmin.

Tmin is lowered by multiplying (Tmin - Tsat) by 0.69, an estimated factor that accounts for Inconel wall properties rather than zircaloy. Figure 3-12 shows the PCT results. ((

)) Again, it shows that use of the TRACG quench model is needed for a reasonable agreement with test data.

In summary, the above TRACG comparison to the Halden experiments further validates the TRACG quench model at ATWS with instability conditions.

References 3-1 HWR-552, "OECD Halden Reactor Project - The Third Dryout Fuel Behaviour Test Series in IFA-613," February 1998.

3-2 R.W. Shumway, "TRAC-BWR Heat Transfer: Assessment of Tmin," EGG-RST-6781, January 1985.

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 11 of 23 1[

Figure 3-1. TRACG PCT Results Compared to Test 3 1[

Figure 3-2. TRACG Inlet Flow Inputs for Test 3

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 12 of 23

((

Figure 3-3. TRACG PCT Results Compared to Test 4 1]

Figure 3-4. TRACG Inlet Flow Inputs for Test 4

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 13 of 23

[1 Figure 3-5. TRACG PCT Results Compared to Test 4 - Nodalization Study 1[

Figure 3-6. TRACG Quench Front Elevation - Nodalization Study

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 14 of 23 Figure 3-7. TRACG PCT Results Compared to Test 4 -

Effects of Quench Model and Tmin Model

((

Figure 3-8. TRACG PCT Results Compared to Test 11

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 15 of 23 1[

Figure 3-9. TRACG Inlet Flow Inputs for Test 11

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 16 of 23 1r

]1 Figure 3-10. TRACG PCT Results Compared to Test 12

]I Figure 3-11. TRACG Inlet Flow Inputs for Test 12

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 17 of 23

((

Figure 3-12. TRACG PCT Results Compared to Test 12 -

Effects of Quench Model and Tmin Model

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 18 of 23 NRC RAI 4 Provide the TRACG input decks for the Halden experiments including the digitized data from the experiments used to compare the results. In addition, please provide the TRACG output file and CEDAR file (in ascii if possible).

GEH Response The following files, which are in ASCII format, are provided on the Enclosure 2 CDROM. Descriptions of variables are contained in the TRACG User's Manual, Reference 4-1, which is also provided on the CDROM. The entirety of the content of all of the data files on the CDROM is Proprietary.

Case Steady-State Transient Input Transient Transient Graphics as~ B-aseldeck ~ File,~ Output File ~ File 03 RUN SS03.BDK TRANS RUN03.INP RUN TR03.OUT RUN TR03-GTRAC.GRA 04 RUN SS04.BDK TRANS RUN04.INP RUN TR04.OUT RUN TR04-GTRAC.GRA 11 RUN SS11.BDK TRANS RUN11.INP RUN TR 1.OUT RUN TR11-GTRAC.GRA 12 RUN SS12.BDK TRANS RUN12.INP RUN TR12.OUT RUN TR12-GTRAC.GRA In addition, the file PCTExperiment.txt is provided that contains the measured clad temperatures extracted from the test report for the four experiments of interest.

The PCT is taken from 5 centimeters from the top of the heated portion of the rod. This corresponds to TRACG parameter RODT230136 for Cases 3 and 4 that use the fresh-fuel rod model and to RODT230138 for Cases 11 and 12 that use the irradiated rod model.

It is noted that the TRACG initial time corresponds to different experiment times:

• Experiment 3 test time of 15.0 seconds corresponds to a TRACG time of 0.0 seconds

" Experiment 4 test time of 30.0 seconds corresponds to a TRACG time of 0.0 seconds

" Experiment 11 c test time of 930.0 seconds corresponds to a TRACG time of 930.0 seconds.

However, the TRACG input conditions prior this time differ. TRACG assumes steady conditions prior to this time.

• Experiment 12 test time of 40.0 seconds corresponds to a TRACG time of 40.0 seconds.

However, the TRACG input conditions prior this time differ. TRACG assumes steady conditions prior to this time.

References 4-1 TRACG04P User's Manual, eECPER 0000-0009-7189-03, December 2011.

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 19 of 23 NRC RAI 5 Reproduce the ATWSI calculations for MNGP with and without applying the void and the Zr credit in the Shumway Tmin correlation using the latest version of the TRACG code.

Provide a comparison of results.

Provide a plot that shows the hot rod clad temperature on the same plot as the calculated Tmin as function of time.

Provide a comparison for the variables shown in Figs 9-12 through 9-14 of NEDC-33435P, Revision 1.

GEH Response The TRACG04 ATWSI Turbine Trip with Full Bypass calculation presented in Figures 9-12 through 9-14 of NEDC-33435P, Revision 1 is reproduced with the latest version of TRACG04. There has been a TRACG04 version change since the cases were run and the cases presented in NEDC-33435P, Revision 1 have a relatively coarse graphics interval (the time interval for graphical data output);

therefore, all the comparison plots shown below are between runs made with the latest version of TRACG04. Note that a special version of TRACG04 is created to enable the requested Shumway sensitivity to be performed and all cases discussed use the ((

)) and some form of the Shumway Minimum Stable Film Boiling Temperature (Tmin) correlation (Reference 5-1).

Three cases are run in this sensitivity. Case 1, Shumway, is a reproduction of the case in NEDC-33435P, Revision 1. Case 2, Shumway - No Void, uses the Shumway Tmin correlation without the void dependence term applied (See Equation 19 of Reference 5-1) and uses Zr properties in the Shumway Beta term. Case 3, Shumway - No Void, SS304 Properties, uses the Shumway Tmin correlation without the void dependence term and uses Stainless Steel 304 (SS304) material properties in the Shumway Beta Term (See Equation 10 and 19 in Reference 5-1). Use of the SS304 properties lowers the Tmin value relative to using the Zr material properties.

Table 5-1 shows the Peak Cladding Temperature (PCT) results for the cases run for this RAI and the result shown in Table 9-5 of NEDC-33435P, Revision 1.

Table 5-1 Tmin Sensitivity Results C C DctPeak Cladding Temperature (K), Limit 2200 0 F.

Original NEDC-33435P 1 Latest TRACG, Shumway (( ))

2 Latest TRACG, Shumway - No Void 3 Latest TRACG, Shumway - No Void, SS304 Properties (( _))

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 20 of 23 Figures 5-1 through 5-3 show the requested Tmin sensitivities. Figures 5-1 and 5-2 show that the ((

)) Figure 5-3 shows that the ((

))The Beta term is related to the interface temperature between the liquid and wall at the conditions that maintain stable film boiling. Reference 5-2 includes several different types of wall and material properties and provides a basis for the Beta term used in Shumway. ((

)) Given that dependence on the Beta term is supported by the data in Reference 5-2 the use of the Shumway correlation with Stainless steel material properties is considered a bounding sensitivity.

Figure 5-4 shows the fuel rod surface temperature and Tmin at Node 13 of the hot fuel rod in Channel 112 for the three Shumway sensitivity cases. ((

))

Figure 5-5 shows the fuel rod surface temperature and Tmin value at Node 21 of the hot fuel rod in Channel 112 for the Shumway - No Void and the No Void, SS304 Properties cases. The figure also shows the elevation of the quench front for the hot fuel rod in the two cases. ((

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 21 of 23

[1 Figure 5-1 Tmin Sensitivity Results - Core Power

[1 1]

Figure 5-2 Tmin Sensitivity Results - Hot Channel Power

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 22 of 23 1[

Figure 5-3 Tmin Sensitivity Results - Channel 112 PCT

[1 Figure 5-4 Tmin Sensitivity Results - Node 13

GE-MNGP-AEP-3223 Non-Proprietary Information - Class I (Public) Page 23 of 23

((

]1 Figure 5-5 Tmin Sensitivity Results - Node 21 References 5-1. R. W. Shumway, EGG-RST-6781, "TRAC-BWR Heat Transfer: Assessment of Tmin,"

January 1985.

5-2. Robert E. Henry, "A Correlation for the Minimum Film Boiling Temperature," Heat Transfer-Research and Design, AIChE Symposium Series No. 138, Vol. 70.

L-MT-12-108 ENCLOSURE 4 GENERAL ELECTRIC - HITACHI AFFIDAVIT FOR WITHHOLDING PROPRIETARY INFORMATION 3 pages follow

GE-Hitachi Nuclear Energy Americas LLC AFFIDAVIT I, Francis T. Bolger, state as follows:

(1) 1 am Manager, New Product Introduction, GE-Hitachi Nuclear Energy Americas LLC

("GEH"), and have been delegated the function of reviewing the information described in paragraph (2) which is sought to be withheld, and have been authorized to apply for its withholding.

(2) The information sought to be withheld is contained in Enclosures 1 and 2 (CDROM) of GEH letter GE-MNGP-AEP-3223, L King (GEH) to J l3jorseth (NSPM),

Subject:

Response

to Monticello Nuclear Generating Plant - Draft Requests for Additional Information re:

MELLLA+ License Amendment Request Review (TAC No. ME3145) - Revision 1, dated December 14, 2012. In Enclosure 1, GEH proprietary text is identified by dark red text inside double square brackets. ((.This. sentence..is an .examp.le...(3)1] Figures and large objects containing proprietary information are identified with double square brackets before and after the object. The label of the CDROM carries the notation "GEH Proprietary Information - Class III (Confidential) (3*. Enclosure 2 (CDROM) is Proprietary in its entirety. In each case, the superscript notation (3} refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination.

(3) In making this application for withholding of proprietary information of which it is the owner or licensee, GEH relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 USC Sec. 552(b)(4), and the Trade Secrets Act, 18 USC Sec. 1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.390(a)(4) for "trade secrets" (Exemption 4). The material for which exemption from disclosure is here sought also qualify under the narrower definition of "trade secret", within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission, 975F2d871 (DC Cir. 1992), and Public Citizen Health Research Group v. FDA, 704F2d1280 (DC Cir. 1983).

(4) Some examples of categories of information which fit into the definition of proprietary information are:

a. Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by GEH's competitors without license from GEH constitutes a competitive economic advantage over other companies;

b. Information which, if used by a competitor, would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product; GE-MNGP-AEP-3223 Enclosures 1 and 2 Affidavit Page I of 3

c. Information which reveals aspects of past, present, or future GEH customer-funded development plans and programs, resulting in potential products to GEH;

d. Information which discloses patentable subject matter for which it may be desirable to obtain patent protection.

The information sought to be withheld is considered to be proprietary for the reasons set forth in paragraphs (4)a. and (4)b. above.

(5) To address 10 CFR 2.390(b)(4), the information sought to be withheld is being submitted to NRC in confidence. The information is of a sort customarily held in confidence by GEH, and is in fact so held. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by GEH, no public disclosure has been made, and it is not available in public sources. All disclosures to third parties, including any required transmittals to NRC, have been made, or must be made, pursuant to regulatory provisions or proprietary agreements which provide for maintenance of the information in confidence. Its initial designation as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set forth in paragraphs (6) and (7) following.

(6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge, or subject to the terms under which it was licensed to GEH. Access to such documents within GEH is limited on a "need to know" basis.

(7) The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist, or other equivalent authority for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside GEH are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary agreements.

(8) The information identified in paragraph (2) is classified as proprietary because it contains a detailed description, including the process and methodology, for application of TRACG to the performance of evaluations for BWRs. The development, reporting, evaluation and interpretations of the results, as they relate to the BWR was achieved at a significant cost to GEH or its licensor.

The development of this methodology, along with the testing, development and approval of the methodology is derived from an extensive experience database that constitutes a major asset of GEH or its licensor.

GE-MNGP-AEP-3223 Enclosures 1 and 2 Affidavit Page 2 of 3

(9) Public disclosure of the information sought to be withheld is likely to cause substantial harm to GEH's competitive position and foreclose or reduce the availability of profit-making opportunities. The information is part of GEH's comprehensive BWR safety and technology base, and its commercial value extends beyond the original development cost.

The value of the technology base goes beyond the extensive physical database and analytical methodology and includes development of the expertise to determine and apply the appropriate evaluation process. In addition, the technology base includes the value derived from providing analyses done with NRC-approved methods.

The research, development, engineering, analytical and NRC review costs comprise a substantial investment of time and money by GEH.

The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial.

GEH's competitive advantage will be lost if its competitors are able to use the results of the GEH experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions.

The value of this information to GEH would be lost if the information were disclosed to the public. Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive GEH of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing and obtaining these very valuable analytical tools.

I declare under penalty of perjury that the foregoing affidavit and the matters stated therein are true and correct to the best of my knowledge, information, and belief.

Executed on this 14 th day of December 2012.

racsT. Bolgeir Manager New Product Introduction GE-Hitachi Nuclear Energy Americas LLC 3901 Castle Hayne Road Wilmington, NC 28401 GE-MNGP-AEP-3223 Enclosures 1 and 2 Affidavit Page 3 of 3