ML032130047

RAI, Alternate Source Term Submittal

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

(TAC NO. MB8365)

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

(TAC NO. MB8365)

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

OGC

ACRS

GHill (2)

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

Exelon Generation Company, LLC

4300 Winfield Road

Warrenville, Illinois 60555

Vice President - Mid-West Opns Support

Exelon Generation Company, LLC

4300 Winfield Road

Warrenville, Illinois 60555

Senior Vice President - Mid-West

Regional Operating Group

Exelon Generation Company, LLC

4300 Winfield Road

Warrenville, Illinois 60555

Vice President - Licensing and

Regulatory Affairs

Exelon Generation Company, LLC

4300 Winfield Road

Warrenville, Illinois 60555

Manager Licensing - Clinton

Exelon Generation Company, LLC

4300 Winfield Road

Warrenville, IL 60555

Regulatory Assurance Manager - Clinton

AmerGen Energy Company, LLC

Clinton Power Station

RR3, Box 228

Clinton, IL 61727-9351

Director- Licensing

Mid-West Regional Operating Group

Exelon Generation Company, LLC

Senior Counsel, Nuclear

Mid-West Regional Operating Group

Exelon Generation Company, LLC

4300 Winfield Road

Warrenville, Illinois 60555

Document Control Desk-Licensing

Exelon Generation Company, LLC

4300 Winfield Road

Warrenville, Illinois 60555

Site Vice President - Clinton Power Station

AmerGen Energy Company, LLC

Clinton Power Station

RR 3, Box 228

Clinton, IL 61727-9351

Clinton Power Station Plant Manager

AmerGen Energy Company, LLC

Clinton Power Station

RR 3, Box 228

Clinton, IL 61727-9351

Resident Inspector

U.S. Nuclear Regulatory Commission

RR #3, Box 229A

Clinton, IL 61727

R. T. Hill

Licensing Services Manager

General Electric Company

175 Curtner Avenue, M/C 481

San Jose, CA 95125

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:

-2-

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

-3-

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

penetrations.

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.