67922 Federal Register / Vol. 62, No. 249 / Tuesday, December 30, 1997 / Notices

Date, Time & Room:

January 14, 1998; 8:30 am–5:00 pm; NSF

Conference Room 380

January 19, 1998; 8:30 am–5:00 pm; NSF

Conference Room 390

January 20, 1998; 8:30 am–5:00 pm; NSF

Conference Room 390

January 21, 1998; 8:30 am–5:00 pm; NSF

Conference Room 390

January 22, 1998; 8:30 am–5:00 pm; NSF

Conference Room 320

January 23, 1998; 8:30 am–5:00 pm; NSF

Conference Room 320

Place: National Science Foundation, 4201

Wilson Boulevard, Arlington, VA 22230.

Type of Meeting: Closed

Contact Person: Dr. Lorretta J. Inglehart,

Program Director, National Facilities and

Instrumentation, Division of Materials

Research, Room 1065, National Science

Foundation 4201 Wilson Boulevard,

Arlington, VA 22230, Telephone: (703) 306–

1817.

Purpose of Meeting: To provide advice and

recommendations concerning proposals

submitted to NSF for financial support.

Agenda: To review and evaluate the 1998

Proposals for Instrumentation in Materials

Research (IMR) as part of the selection

process for awards.

Reason For Closing: The proposals being

reviewed include information of a

proprietary or confidential nature, including

technical information; financial data, such as

salaries and personal information concerning

individuals associated with the proposals.

These matters are exempt under 5 U.S.C. 552

b(c) (4) and (6) of the Government in the

Sunshine Act.

Dated: December 22, 1997.

M. Rebecca Winkler,

Committee Management Officer.

[FR Doc. 97–33899 Filed 12–29–97; 8:45 am]

BILLING CODE 2555–01–M

NATIONAL SCIENCE FOUNDATION

Special Emphasis Panel in Physics;

Notice of Meeting

In accordance with the Federal

Advisory Committee Act (Pub. L. 92–

463, as amended), the National Science

Foundation announces the following

meeting.

Name: Special Emphasis Panel in Physics

(1208).

Date and Time: Thursday, January 15, 1998

8:00am–5:00pm; Friday, January 16, 1998

8:00am–5:00pm.

Place: Room 920, 4201 Wilson Blvd.

Arlington, VA 22230.

Type of Meeting: Closed.

Contact Person: Dr. Marvin Goldberg,

Program Director for Elementary Particle

Physics, Division of Physics, Rm 1015,

National Science Foundation, 4201 Wilson

Blvd., Arlington, VA 22230. Telephone: (703)

306–1894.

Purpose of Meeting: To review proposals

submitted to NSF for financial support,

especially in experiments involving

international collaborations.

Agenda: Reviewing and evaluating

Elementary Particle Physics proposals as part

of the selection process for awards.

Reason for Closing: The proposals being

reviewed include information of a

proprietary or confidential nature, including

technical information; financial data, such as

salaries; and personal information

concerning individuals associated with the

proposals. These matters are exempt under 5

U.S.C. 552b(c) (4) and (6) of the Government

in the Sunshine Act.

Dated: December 22, 1997.

M. Rebecca Winkler,

Committee Management Officer.

[FR Doc. 97–33900 Filed 12–29–97; 8:45 am]

BILLING CODE 7555–01–M

NATIONAL SCIENCE FOUNDATION

Special Emphasis Panel in

Undergraduate Education; Notice of

Meetings

This notice is being published in

accord with the Federal Advisory

Committee Act (Pub. L. 92–463, as

amended). During the periods January

through April, 1997, the Special

Emphasis Panel will be holding panel

meetings to review and evaluate

research proposals. The dates, contact

person, and types of proposals are as

follows: Special Emphasis Panel in

Division of Undergraduate Education.

1. Date: January 11–13, 1998.

Contact: Terry Woodin, Program Director,

Room 835, 703–306–1666 TIMES: 7:30 p.m.

to 9:30 p.m. (January 11); 8:30 a.m. to 5:00

p.m. each day (January 12–13).

Place: National Science Foundation, 4201

Wilson Boulevard, Arlington, VA.

Type of Proposal: NSF Collaboratives for

Excellence in Teacher Preparation (CETP)

Program Reverse Site.

2. Date: January 21–24, 1998.

Contact: Duncan McBride, Program

Director, Room 835, 703–306–1666 TIMES:

7:30 p.m. to 9:30 p.m. (January 21); 8:30 a.m.

to 5:00 p.m. each day (January 22–23); 8:30

a.m. to 1:00 p.m. (January 24) PLACE:

Doubletree Hotel, 300 Army/Navy Drive,

Arlington, VA.

Type of Proposal: Instrumentation &

Laboratory Improvement (ILI) Program Phase

I.

Date: January 28–31, 1998.

Contact: Duncan McBride, Program

Director, Room 835, 703–306–1666 TIMES:

7:30 p.m. to 9:30 p.m. (January 28); 8:30 a.m.

to 5:00 p.m. each day (January 29–30); 8:30

a.m. to 1:00 p.m. (January 31) PLACE:

Doubletree Hotel, 300 Army/Navy Drive,

Arlington, VA.

Type of Proposal: Instrumentation &

Laboratory Improvement (ILI) Program Phase

II.

4. Date: April 6–8, 1998.

Contact: Terry Woodin, Program Director,

Room 835, 703–306–1666 TIMES: 7:30 p.m.

to 9:30 p.m. (April 6); 8:30 a.m. to 5:00 p.m.

each day April 7–8.

Place: National Science Foundation, 4201

Wilson Blvd., Arlington, VA TYPE OF.

Proposal: NSF Collaboratives for

Excellence in Teacher Preparation (CETP).

Program Reverse Site (3rd Year).

Type of Meetings: Closed.

Purpose of Meetings: To provide advice

and recommendations concerning proposals

submitted to NSF for financial support.

Agenda: To review and evaluate proposals

submitted to the Directorate as part of the

selection process for awards.

Reason For Closing: The proposals being

reviewed include information of a

proprietary or confidential nature, including

technical information, financial data, such as

salaries, and personal information

concerning individuals associated with the

proposals. These matters are exempt under 5

U.S.C. 552b(c) (4) and (6) of the Government

in the Sunshine Act.

Dated: December 22, 1997.

M. Rebecca Winkler,

Committee Management Officer.

[FR Doc. 97–33901 Filed 12–29–97; 8:45 am]

BILLING CODE 7555–01–M

NUCLEAR REGULATORY

COMMISSION

[Docket No. STN 50–457]

Commonwealth Edison Company

(Braidwood Nuclear Station, Unit No.

2); Exemption

I.

Commonwealth Edison Company

(ComEd, the licensee) is the holder of

Facility Operating License No. NPF–77,

which authorizes operation of the

Braidwood Nuclear Station, Unit 2. The

license provides, among other things,

that the licensee is subject to all rules,

regulations, and orders of the

Commission now or hereafter in effect.

II.

In its letter dated November 30, 1994,

as supplemented on May 11, 1995, the

licensee requested an exemption from

the Commission’s regulations. Title 10

of the Code of Federal Regulations, Part

50, Section 60 (10 CFR 50.60),

‘‘Acceptance Criteria for Fracture

Prevention Measures for Lightwater

Nuclear Power Reactors for Normal

Operation,’’ states that all lightwater

nuclear power reactors must comply

with the fracture toughness and material

surveillance program requirements for

the reactor coolant pressure boundary as

stated in Appendices G and H to 10 CFR

Part 50. Appendix G to 10 CFR Part 50

defines pressure-temperature (P–T)

limits during any condition of normal

operation, including anticipated

operational occurrences and system

hydrostatic tests to which the pressure

boundary may be subjected over its
Federal Register / Vol. 62, No. 249 / Tuesday, December 30, 1997 / Notices 67923

service lifetime, and that are obtained

by conforming to the methods of

analysis and the margins of safety in the

American Society of Mechanical

Engineers (ASME) Boiler and Pressure

Vessel Code (Code), Section XI,

Appendix G. It is required in 10 CFR

50.55a that any reference to the ASME

Code, Section XI, in 10 CFR Part 50

refers to the addenda through the 1988

Addenda and editions through the 1989

Edition of the Code unless otherwise

noted. It is specified in 10 CFR 50.60(b)

that alternatives to the described

requirements in Appendix G to 10 CFR

Part 50 may be used when an exemption

is granted by the Commission under 10

CFR 50.12.

To mitigate low-temperature

overpressure transients that would

produce pressure excursions exceeding

the required limits while the reactor is

operating at low temperatures, the

licensee installed a low-temperature

overpressure protection (LTOP) system.

The system contains pressure-relieving

devices called power-operated relief

valves (PORVs). The PORVs are set at a

low enough pressure so that if an LTOP

transient occurred, the mitigation

system would prevent the pressure in

the reactor vessel from exceeding the

required limits. To prevent the PORVs

from lifting as a result of normal

operating pressure surges, some margin

is needed between the PORV setpoint

and the normal operating pressure. In

addition, normal operating pressure

must be high enough to prevent damage

to reactor coolant pumps that may result

from cavitation or inadequate

differential pressure across the pump

seals. Hence, the licensee must operate

the plant within a pressure window that

is defined as the difference between the

minimum pressure required for reactor

coolant pumps and the operating margin

to keep the PORVs from lifting. When

instrument uncertainty is considered,

the operating window is small and

presents difficulties for plant operation.

The licensee has requested the use of

the ASME Code Case N–514, ‘‘Low

Temperature Overpressure Protection,’’

for determining the LTOP system

setpoint. Code Case N–514 allows use of

an LTOP system setpoint so that system

pressure does not exceed 110 percent of

the P–T limits during an LTOP event.

Code Case N–514 is consistent with

guidelines developed by the ASME

Working Group on Operating Plant

Criteria to define pressure limits during

LTOP events that avoid certain

unnecessary operational restrictions,

provide adequate margins against failure

of the reactor pressure vessel, and

reduce the potential for unnecessary

activation of pressure-relieving devices

used for LTOP. The content of this code

case has been incorporated into the

ASME Code, Section XI, Appendix G,

and was published in the 1993 Addenda

to Section XI.

III.

Pursuant to 10 CFR 50.12, the

Commission may, upon application by

any interested person or upon its own

initiative, grant exemptions from the

requirements of 10 CFR Part 50 (1) when

the exemptions are authorized by law,

will not present an undue risk to public

health or safety, and are consistent with

the common defense and security; and

(2) when special circumstances are

present. Special circumstances are

present whenever, according to 10 CFR

50.12(a)(2)(ii), ‘‘Application of the

regulation in the particular

circumstances would not serve the

underlying purpose of the rule or is not

necessary to achieve the underlying

purpose of the rule * * *.’’

The underlying purpose of 10 CFR

50.60 and 10 CFR Part 50, Appendix G,

is to establish fracture toughness

requirements for ferritic materials of

pressure-retaining components of the

reactor coolant pressure boundary to

provide adequate margins of safety

during any condition of normal

operation, including anticipated

operational occurrences, to which the

pressure boundary may be subjected

over its service lifetime. Section IV.A.2

of Appendix G to 10 CFR Part 50

requires that the reactor vessel be

operated with P–T limits at least as

conservative as those obtained from

following the methods of analysis and

the required margins of safety of

Appendix G of Section XI of the ASME

Code.

Appendix G of the ASME Code

requires that the P–T limits be

calculated (1) Using a safety factor of 2

on the principal membrane (pressure)

stresses, (2) assuming a flaw at the

surface with a depth of one-fourth of the

vessel wall thickness and a length of 6

times its depth, and (3) using a

conservative fracture toughness curve

that is based on the lower bound of

static, dynamic, and crack arrest fracture

toughness tests on material similar to

the Braidwood reactor vessel material.

For determining the LTOP system

setpoint, the licensee proposed to use

safety margins based on an alternate

methodology consistent with ASME

Code Case N–514. The code case allows

the setpoint for mitigating LTOP events

to be so determined that the maximum

pressure in the vessel would not exceed

110 percent of the Appendix G P–T

limits. This results in a safety factor of

1.8 on the principal membrane stresses.

All other factors, including assumed

flaw size and fracture toughness, remain

the same. Although this methodology

would reduce the safety factor on the

principal membrane stresses, the

proposed criteria will produce adequate

margins of safety for the reactor vessel

during LTOP transients and, thus, will

satisfy the underlying purpose of 10

CFR 50.60 for fracture toughness

requirements. Further, by relieving the

operational restrictions, the potential for

undesirable lifting of the PORVs would

be reduced, thereby making the plant

safer.

IV.

For the foregoing reasons, the NRC

staff has concluded that the licensee’s

proposed use of the alternate

methodology in determining the

acceptable setpoint for LTOP events will

not present an undue risk to public

health and safety and is consistent with

the common defense and security. The

NRC staff has determined that there are

special circumstances present, as

specified in 10 CFR 50.12(a)(2)(ii), in

that application of 10 CFR 50.60 is not

necessary in order to achieve the

underlying purpose of this regulation

which is to provide adequate fracture

toughness of the reactor pressure

boundary.

Accordingly, the Commission has

determined that, pursuant to 10 CFR

50.12(a), an exemption is authorized by

law, will not endanger life or property

or the common defense and security,

and is, otherwise, in the public interest.

Therefore, the Commission hereby

grants an exemption from the

requirements of 10 CFR 50.60; in

accordance with ASME Code Case

N–514, the LTOP system setpoint may

be determined so that system pressure

does not exceed 110 percent of the

Appendix G P–T limits in order to be in

compliance with these regulations. This

exemption is applicable only to LTOP

conditions during normal operation.

Pursuant to 10 CFR 51.32, the

Commission has determined that

granting this exemption will not have a

significant effect on the quality of the

human environment (62 FR 59008).

This exemption is effective upon

issuance.

Dated at Rockville, Maryland, this 12th day

of December 1997.

For the Nuclear Regulatory Commission.

Frank J. Miraglia,

Acting Director, Office of Nuclear Reactor

Regulation.

[FR Doc. 97–33846 Filed 12–29–97; 8:45 am]

BILLING CODE 7590–01–P