ML032130047
| ML032130047 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 10/30/2003 |
| From: | Pickett D NRC/NRR/DLPM/LPD3 |
| To: | Skolds J AmerGen Energy Co |
| Pickett , NRR/DLPM, 415-1364 | |
| References | |
| RIS-02-019, TAC MB8365 | |
| Download: ML032130047 (9) | |
See also: RIS 2002-19
Text
October 30, 2003
Mr. John L. Skolds, Chairman
and Chief Executive Officer
AmerGen Energy Company, LLC
4300 Winfield Road
Warrenville, Illinois 60555
SUBJECT: CLINTON POWER STATION, UNIT 1 - REQUEST FOR ADDITIONAL
INFORMATION REGARDING ALTERNATE SOURCE TERM SUBMITTAL
Dear Mr. Skolds:
By letter dated April 3, 2003 (RS-03-060), AmerGen Energy Company, LLC, submitted a
license amendment application to Facility Operating License No. NPF-62 for the Clinton Power
Station to support application of an alternative source term methodology pursuant to Section
50.67, Accident Source Term of Title 10 of the Code of Federal Regulations (10 CFR).
The enclosed request for additional information (RAI) will be necessary for the staff to make the
requisite determination that the analyzed radiological consequences for the design-basis
accident at the Clinton facility, as modified by the proposed changes, will continue to comply
with applicable dose limits. If you believe that any of this information has already been
docketed, please provide a specific citation. Please refer to Regulatory Information Summary
2001-19, Deficiencies in the Documentation of Design Basis Radiological Analysis Submitted
in Conjunction with License Amendment Requests, for further explanation of the staffs data
needs.
In addition to the enclosed RAI, the staff is preparing a standard set of questions concerning
the standby liquid control system which will be provided to you at a later date.
Sincerely,
/RA/
Douglas V. Pickett, Senior Project Manager, Section 2
Project Directorate III
Division of Licensing Project Management
Office of Nuclear Reactor Regulation
Docket No. 50-461
Enclosure: Request for Additional Information
cc w/encls: See next page
October 30, 2003
Mr. John L. Skolds, Chairman
and Chief Executive Officer
AmerGen Energy Company, LLC
4300 Winfield Road
Warrenville, Illinois 60555
SUBJECT: CLINTON POWER STATION, UNIT 1 - REQUEST FOR ADDITIONAL
INFORMATION REGARDING ALTERNATE SOURCE TERM SUBMITTAL
Dear Mr. Skolds:
By letter dated April 3, 2003 (RS-03-060), AmerGen Energy Company, LLC, submitted a
license amendment application to Facility Operating License No. NPF-62 for the Clinton Power
Station to support application of an alternative source term methodology pursuant to Section
50.67, Accident Source Term of Title 10 of the Code of Federal Regulations (10 CFR).
The enclosed request for additional information (RAI) will be necessary for the staff to make the
requisite determination that the analyzed radiological consequences for the design-basis
accident at the Clinton facility, as modified by the proposed changes, will continue to comply
with applicable dose limits. If you believe that any of this information has already been
docketed, please provide a specific citation. Please refer to Regulatory Information Summary
2001-19, Deficiencies in the Documentation of Design Basis Radiological Analysis Submitted
in Conjunction with License Amendment Requests, for further explanation of the staffs data
needs.
In addition to the enclosed RAI, the staff is preparing a standard set of questions concerning
the standby liquid control system which will be provided to you at a later date.
Sincerely,
/RA/
Douglas V. Pickett, Senior Project Manager, Section 2
Project Directorate III
Division of Licensing Project Management
Office of Nuclear Reactor Regulation
Docket No. 50-461
Enclosure: Request for Additional Information
cc w/encls: See next page
DISTRIBUTION:
PUBLIC PD3-2 r/f AMendiola
THarris DPickett RDennig
GGrant, RIII
ADAMS Accession Number: ML032130047
OFFICE PM:PD3-2 LA:PD3-2 SC:SPSB SC:PD3-2
NAME DPickett THarris RDennig* WRuland for,
AMendiola
DATE 10/30/2003 10/29/2003 10/28/03 10/30/2003
- See previous concurrence OFFICIAL RECORD COPY
Clinton Power Station, Unit 1
cc:
Senior Vice President - Nuclear Services Senior Counsel, Nuclear
Exelon Generation Company, LLC Mid-West Regional Operating Group
4300 Winfield Road Exelon Generation Company, LLC
Warrenville, Illinois 60555 4300 Winfield Road
Warrenville, Illinois 60555
Vice President - Mid-West Opns Support
Exelon Generation Company, LLC Document Control Desk-Licensing
4300 Winfield Road Exelon Generation Company, LLC
Warrenville, Illinois 60555 4300 Winfield Road
Warrenville, Illinois 60555
Senior Vice President - Mid-West
Regional Operating Group Site Vice President - Clinton Power Station
Exelon Generation Company, LLC AmerGen Energy Company, LLC
4300 Winfield Road Clinton Power Station
Warrenville, Illinois 60555 RR 3, Box 228
Clinton, IL 61727-9351
Vice President - Licensing and
Regulatory Affairs Clinton Power Station Plant Manager
Exelon Generation Company, LLC AmerGen Energy Company, LLC
4300 Winfield Road Clinton Power Station
Warrenville, Illinois 60555 RR 3, Box 228
Clinton, IL 61727-9351
Manager Licensing - Clinton
Exelon Generation Company, LLC Resident Inspector
4300 Winfield Road U.S. Nuclear Regulatory Commission
Warrenville, IL 60555 RR #3, Box 229A
Clinton, IL 61727
Regulatory Assurance Manager - Clinton
AmerGen Energy Company, LLC R. T. Hill
Clinton Power Station Licensing Services Manager
RR3, Box 228 General Electric Company
Clinton, IL 61727-9351 175 Curtner Avenue, M/C 481
San Jose, CA 95125
Director- Licensing
Mid-West Regional Operating Group
Exelon Generation Company, LLC
4300 Winfield Road
Warrenville, Illinois 60555
Clinton Power Station, Unit 1
cc:
Regional Administrator, Region III
U.S. Nuclear Regulatory Commission
801 Warrenville Road
Lisle, IL 60532-4351
Chairman of DeWitt County
c/o County Clerks Office
DeWitt County Courthouse
Clinton, IL 61727
J. W. Blattner
Project Manager
Sargent & Lundy Engineers
55 East Monroe Street
Chicago, IL 62704
Illinois Department of Nuclear Safety
Office of Nuclear Facility Safety
1035 Outer Park Drive
Springfield, IL 62704
REQUEST FOR ADDITIONAL INFORMATION
APPLICATION OF ALTERNATE SOURCE TERM
CLINTON POWER STATION, UNIT 1
DOCKET NO. 50-461
1. On Page 8 of Attachment 2 to the April 3, 2003, submittal, the last paragraph states that
the leakage of air from the feedwater isolation valve (FWIV) would be 10.98 cfm for a
1-hour period until the feedwater piping is filled with water. However, Table 4 on Page
18 of 35, states the leakage as 10.98 cfm for each of two penetrations from 21.15
minutes to 1-hour, a period of less than 40 minutes. The table on Page 27 of 35 states
that the leakage is 10.98 cfm total. Similar confusion exists over the 2 gpm value after
1-hour. Please clarify the appropriate leakage value, onset, and duration. Please
confirm that the analyses were performed using the correct values. If the 21.15 minute
leakage onset is correct, please provide the basis for this onset timing.
2. On Page 9 of Attachment 2 to the submittal, the third paragraph states that since a
separate dose analysis has been performed for the primary containment purge lines, the
leakage from these penetrations no longer need to be considered in determining
compliance with the secondary containment bypass leakage or primary containment
leakage rate acceptance criteria in technical specifications. This is also shown on Page
18 in Attachment 5. The staff finds this argument to be technically correct but believes
10 CFR Part 50 Appendix J (e.g., III.B.3) requires the leakage from all pathways subject
to testing to be summed. Please provide an explanation of how your proposed protocol
will meet the requirements of Appendix J.
3. On Page 10 of Attachment 2 to the submittal, the control room unfiltered leakage is
established at 600 cfm. Please provide an explanation of the basis or derivation of this
value. Include in your explanation any testing results that confirm the assumed value.
4. On Page 11 of Attachment 2 to the submittal, the second paragraph states that
AmerGen has used the Brockmann-Bixler model for main steamline deposition. The
discussion and the data in Table 6 are insufficient to support staff confirmation. Please
provide the following information.
a. A single-line sketch of the four main steamlines and the isolation valves.
Annotate this sketch to identify each of the control volumes assumed by
AmerGen in the deposition model.
b. A tabulation of all of the parameters input into the Brockmann-Bixler model for
each control volume shown in the sketch (and time step) for which AmerGen is
crediting deposition. This includes:
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- Flow rate
- Gas pressure
- Gas temperature
- Volume
- Inner surface area
- Total pipe bend angle
c. For each of the parameters in 5.b, provide a brief derivation and an explanation
why that assumption is adequately conservative for a design-basis calculation.
Address changes in parameters over time, e.g., plant cooldown.
d. Since the crediting of main steamline deposition effectively establishes the main
steam piping as a fission product mitigation system, the staff expects the piping
to meet the requirements of an engineered safety feature system, including
seismic and single-failure considerations. Your submittal does not appear to
address a single-failure of one of the main steam isolation valve (MSIVs). Such
a failure could change the control volume parameters that are input to the
deposition model. Previous implementations of main steam deposition have
been found acceptable only if the licensee had modeled a limiting single-failure.
Please explain why AmerGen feels that such a limiting failure need not be
considered.
e. Please confirm that the main steam piping and isolation valves that establish the
control volumes for the modeling of deposition were designed and constructed to
maintain integrity in the event of the safe shutdown basis earthquake for Clinton.
If the design-basis for the piping and components does not include integrity
during earthquakes, please provide an explanation of how the Clinton design
satisfies the prerequisites of the staff-approved NEDC-31858P-A, BWROG
Report for Increasing MSIV Leakage Rate Limits and Elimination of Leakage
Control Systems. If piping systems and components at Clinton were previously
found by the staff to be seismically rugged using the methodology of this
BWROG report, please provide a specific reference to the staffs approval.
f. On page 24 of 30 in Table 2, you state that your submittal is in compliance with
Paragraph 6.3 of Appendix A to regulatory guide (RG) 1.183, and reference the
RADTRAD Brockman-Bixler approach apparently as establishing that
conformance. However, Paragraph 6.3 of RG 1.183 states that the model
should be based on well-mixed volumes, but other models such as slug flow may
be used if justified. The Brockman-Bixler model is a slug-flow model. This
paragraph did not endorse RADTRAD as an acceptable approach. RG 1.183
states that main steamline deposition will be considered on a case-by-case
basis. The staff documented its evaluation of the first application of main steam-
line deposition credit in an alternate source term in Appendix A of the staff
report: AEB-98-03, "Assessment of the Radiological Consequences for the
Perry Pilot Plant Application using the Revised (NUREG-1465) Source Term."
The methodology of this report, which can be found online in ADAMS at
ML011230531, was used by at least two additional licensees. The staff did
accept one application of plug flow in which the licensee has committed to
maintaining a seismically rugged drain path from the 3rd MSIV to and through
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the condenser. This safety evaluation is on ADAMS at ML011660142. Please
provide a justification for your proposed modeling approach or re-perform the
analyses.
5. Provide the corresponding information requested in Item 5 for the containment purge
6. Section 4.3 of Attachment 2 to the submittal addresses the main steamline break
accident analysis. AmerGen has proposed a transport model that is based on thermo-
hydraulic rather than the meteorological processes addressed in regulatory guidance.
AmerGens approach appears to maximize the volume of the assumed hemisphere
which minimizes its concentration, exposing the control room intake to a lower
concentration for a longer period. The description in the submittal doesnt provide
sufficient information for the staff to conclude that this is an adequately conservative
approach. Please provide the following information:
a. Whether AmerGen performed a sensitivity analysis to determine if the maximum
hemisphere volume yields the highest control room intake? Did AmerGen
consider heat losses during expansion that could reduce the size of the
expanded hemisphere?
b. The pressure and temperature of the steam at the point of release (prior to
expansion to atmospheric pressure and temperature).
c. A clarification of whether atmospheric pressure and temperature is to be
interpreted as 14.7 psia and the associated saturation temperature. If another
temperature or pressure is assumed, please identify the values and their bases.
d. The assumption regarding control room intake during the puff transit. For
example, a particular flow rate for the duration of the hemisphere movement.
7. Section 4.3 of Attachment 2 to the submittal also states that the meteorological
dispersion model of RG 1.5 is used for offsite doses. The methodology of RG 1.5
requires the release rate to be expressed in terms of release rate. Please explain how
the release quantity for an instantaneous release has been converted to a release rate.
8. Section 4.3 of Attachment 2 to the submittal provides three bullet items related to
establishing the magnitude of the release activity. Please explain the relationship of the
second and third bullet items as they apply to the statement in the first bullet that the
activity in the steam cloud is based on the total mass of water released from the break,
not just that which flashes to steam. These last two bullets appear to conflict with the
first of the three bullets and the break discharge mass entry in Table 8.
9. In Table 4 of Attachment 2 to the submittal, the emergency core cooling system (ECCS)
water component of the FWIV leak rate is reduced at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. It appears that this
assumption is predicated on the RG 1.183 assumption that containment leakage may be
reduced by 50 percent at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. As the staff understands the Clinton design, the
ECCS water is a forced flow intended to seal the penetration. The staff believes that the
pressure associated with this forced flow is that of the ECCS pump discharge pressure,
-4-
less system pressure drops, and is independent of the containment pressure. Please
explain the basis for your assumed reduction at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
10. In Table 4 of Attachment 2 to the submittal, the ECCS system leakage flash fraction is
set at 1.36 percent. Entry 5.5 in Attachment 5 indicates that the value of 1.36 percent is
the current design-basis value derived from ORNL-TM-2412. However, the third
paragraph on Page 9 in Attachment 2 states that the ECCS system leakage is a new
release path for CPS analyzed to comply with RG 1.183. Thus, it would appear that
there is no current licensing basis for the flash fraction.
Paragraph 5.5 of Appendix A of RG 1.183 states that the flash fraction should be
assumed to be 10 percent, unless a smaller value can be justified on the actual sump
pH history and area ventilation rates. Please explain why ORNL-TM-2412 is an
acceptable alternative to the guidance in RG 1.183.
11. In Table 5 of Attachment 2 to the submittal, the control room volume is set at 324,000
cubic feet. Final safety analysis report 6.4.2.1 states that the volume is 405,134 cubic
feet. Please resolve this discrepancy.
12. In Table 5 of Attachment 2 to the submittal, the last table entry refers to inleakage
control necessary to maintain constant iodine protection factor (IPF). Please explain
how these data are being used to show compliance with control room habitability
requirements. Were these two expressions used to establish the 650 cfm filtered and
600 cfm unfiltered inleakage rates shown in Table 5? If these expressions were used as
part of the basis for the inleakage rates, please provide the following information:
a. The derivation of the numeric constants in the two expressions.
b. An explanation of how these expressions were verified and validated.
c. An explanation of how AmerGen resolved the IPF caveat provided in Footnote
15 on Page 1.183-18 of RG 1.183 in finding (as expressed in Table 1 of
Attachment 5 of the submittal) that the AmerGen submittal conformed with
Paragraph 4.2.3 of RG 1.183.
13. On Page 5 of Attachment 2 to the submittal, the last bullet states that AmerGen
developed new offsite and control room atmospheric dispersion factors. Please provide
the following information needed for staff confirmation of these values:
a. The information, including the joint frequency data file, that was input into the
PAVAN code to generate /Q values. An electronic copy or a paper copy of the
PAVAN input file(s) would be an acceptable approach to providing these data.
b. The information, including the meteorological data files, that were used as input
into the ACRON96 code to generate /Q values for the control room. The
meteorological data files should be submitted on electronic media in the format
readable by the ARCON96 code. For the remaining data, tabular data or paper
copies of the ARCON96 input files would be an acceptable approach to
submitting this information.
-5-
14. On Page 8 of Attachment 2 to the April 3, 2003, submittal, the last paragraph states that
the leakage of air from the feedwater isolation valve would be 10.98 cfm for a 1-hour
period until the feedwater piping is filled with water. However, Table 4 on Page 18 of
35, states the leakage as 10.98 cfm for each of two penetrations from 21.15 minutes
to 1- hour, a period of less than 40 minutes. The table on Page 27 of 35 states that the
leakage is 10.98 cfm total. Similar confusion exists over the 2 gpm value after 1-hour.
Please clarify the appropriate leakage value, onset, and duration. Please confirm that
the analyses were performed using the correct values. If the 21.15 minute leakage
onset is correct, please provide the basis for this onset timing.
15. On Page 9 of Attachment 2 to the submittal, the sixth paragraph proposes a new design
function for the standby liquid control (SLC) system as a means of maintaining
suppression pool deposition. General Design Criterion 41 of Appendix A to 10 CFR Part
50 provides requirements for systems to control fission products. Please explain how
SLC system meets the requirements of GDC 41. In particular, address how the system
can accomplish the proposed new design function assuming a single-failure of the
single discharge piping containment isolation check valve.