This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents. Prices of

new books are listed in the first FEDERAL

REGISTER issue of each week.

Rules and Regulations Federal Register

34913

Vol. 65, No. 106

Thursday, June 1, 2000

NUCLEAR REGULATORY

COMMISSION

10 CFR Part 50

RIN 3150–AF95

Monitoring the Effectiveness of

Maintenance at Nuclear Power Plants;

Confirmation of Effective Date and

Availability of Guidance

AGENCY: Nuclear Regulatory

Commission.

ACTION: Final rule: Confirmation of

effective date and availability of

guidance.

SUMMARY: The Nuclear Regulatory

Commission amended its regulation

concerning requirements for monitoring

the effectiveness of maintenance at

nuclear power plants on July 19, 1999

(64 FR 38551). The effective date of this

amendment was deferred until guidance

on assessing and managing increases in

risk associated with maintenance

activities was issued to nuclear power

plant licensees. This document

announces the availability of that

guidance (Regulatory Guide 1.182,

‘‘Assessing and Managing Risk Before

Maintenance Activities at Nuclear

Power Plants’’) and specifies the

effective date for the July 19, 1999,

amendment to the maintenance rule.

EFFECTIVE DATE: November 28, 2000.

ADDRESSES: Regulations, certain

regulatory guides, and certain endorsed

NUMARC documents are available for

inspection or downloading at the NRC’s

web site, <WWW.NRC.GOV>. Single

copies of regulatory guides may be

obtained free of charge by writing the

Reproduction and Distribution Services

Section, U.S. Nuclear Regulatory

Commission, Washington, DC 20555–

0001, or by fax to (301) 415–2289, or by

email to <DISTRIBUTION@NRC.GOV>.

Issued guides may also be purchased

from the National Technical Information

Service on a standing order basis.

Details on this service may be obtained

by writing NTIS, 5285 Port Royal Road,

Springfield, VA 22161. Copies of

regulations, regulatory guides, and

endorsed NUMARC documents are

available for inspection or copying for a

fee from the NRC Public Document

Room at 2120 L Street NW.,

Washington, DC; the PDR’s mailing

address is Mail Stop LL–6, Washington,

DC 20555; telephone (202) 634–3273 or

(800) 397–4209; fax (202) 634–3343;

email <PDR@NRC.GOV>.

Comments and suggestions in

connection with items for inclusion in

regulations and regulatory guides are

encouraged at any time. Written

comments may be submitted to the

Rules and Directives Branch, Office of

Administration, U.S. Nuclear Regulatory

Commission, Washington, DC 20555.

FOR FURTHER INFORMATION CONTACT: W.E.

Scott, Office of Nuclear Reactor

Regulation, U.S. Nuclear Regulatory

Commission, Washington, DC 20555;

telephone (301) 415–1020; email

<WES@NRC.GOV>.

SUPPLEMENTARY INFORMATION:

Background

The Nuclear Regulatory Commission

amended its maintenance rule, 10 CFR

50.65, ‘‘Requirements for monitoring the

effectiveness of maintenance at nuclear

power plants,’’ on July 19, 1999 (64 FR

38551). This amendment requires

nuclear power plant licensees to assess

and manage the increase in risk that

may result from proposed maintenance

activities. The implementation date of

this amendment was made dependent

upon guidance being issued to nuclear

power plant licensees on assessing and

managing increases in risk associated

with maintenance activities.

Rather than issue Revision 3 to

Regulatory Guide 1.160, ‘‘Monitoring

the Effectiveness of Maintenance at

Nuclear Power Plants,’’ the NRC staff

decided to issue Regulatory Guide

1.182, ‘‘Assessing and Managing Risk

Before Maintenance Activities at

Nuclear Power Plants,’’ as guidance to

nuclear power plant licensees on

assessing and managing risk before

maintenance activities are conducted at

the nuclear power plant. Regulatory

Guide 1.182 is being issued as a

companion guide to Regulatory Guide

1.160, which provides guidance on the

structure of the licensees’ maintenance

effectiveness monitoring programs.

Regulatory Guide 1.160 endorses a

document prepared by the Nuclear

Energy Institute (formerly NUMARC),

NUMARC 93–01, ‘‘Industry Guideline

for Monitoring the Effectiveness of

Maintenance at Nuclear Power Plants.’’

Regulatory Guide 1.182 endorses a

revised Section 11, ‘‘Assessment of Risk

Resulting from Performance of

Maintenance Activities,’’ of NUMARC

93–01. Regulatory Guide 1.182 was

published for public comment (64 FR

70098, December 15, 1999) as DG–1082,

‘‘Assessing and Managing Risk Before

Maintenance Activities at Nuclear

Power Plants.’’ There were no public

comments on the draft guide, and NEI

addressed the comments on Section 11

of NUMARC 93–01 with minor

revisions, and the NRC staff concurs in

these revisions.

Therefore, the effective date of the

July 19, 1999, amendment to 10 CFR

50.65 is November 28, 2000.

Dated at Rockville, Maryland, this 26th day

of May, 2000.

For the Nuclear Regulatory Commission.

J. Samuel Walker,

Acting Secretary of the Commission.

[FR Doc. 00–13746 Filed 5–31–00; 8:45 am]

BILLING CODE 7590–01–P

NUCLEAR REGULATORY

COMMISSION

10 CFR Part 50

RIN 3150–AG26

Emergency Core Cooling System

Evaluation Models

AGENCY: Nuclear Regulatory

Commission.

ACTION: Final rule.

SUMMARY: The Nuclear Regulatory

Commission (NRC) is amending its

regulations to allow holders of operating

licenses for nuclear power plants to

reduce the assumed reactor power level

used in evaluations of emergency core

cooling system (ECCS) performance.

This amendment provides licensees the

option to apply a reduced margin for

ECCS evaluation or to maintain the

value of reactor power that had been

mandated in the regulation. This action

allows interested licensees to pursue

small, but cost-beneficial, power uprates

and reduces unnecessary regulatory

34914 Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations

burden without compromising the

margin of safety of a facility.

EFFECTIVE DATE: The rule becomes

effective July 31, 2000.

ADDRESSES: The final rule and any

related documents are available on the

NRC’s rulemaking website at http://

ruleforum.llnl.gov. For information

about the interactive rulemaking

website, contact Ms. Carol Gallagher,

(301) 415–5905 (e-mail: cag@nrc.gov).

FOR FURTHER INFORMATION CONTACT: Mr.

Joseph E. Donoghue, Office of Nuclear

Reactor Regulation, U.S. Nuclear

Regulatory Commission, Washington,

DC 20555–0001; telephone: 301–415–

1131; or by Internet electronic mail to

jed1@nrc.gov.

SUPPLEMENTARY INFORMATION:

Background

A holder of an operating license (i.e.,

the licensee) for a light-water power

reactor is required by regulations issued

by the NRC to submit a safety analysis

report that contains an evaluation of

emergency core cooling system (ECCS)

performance under loss-of-coolant

accident (LOCA) conditions. 10 CFR

50.46, ‘‘Acceptance criteria for

emergency core cooling systems for

light-water nuclear power reactors,’’

requires that ECCS performance under

LOCA conditions be evaluated and that

the estimated performance satisfy

certain criteria. Licensees may conduct

an analysis that ‘‘realistically describes

the behavior of the reactor system

during a LOCA’’ (often termed a ‘‘bestestimate analysis’’), or they may develop

a model that conforms with the

requirements of Appendix K to 10 CFR

part 50. Most ECCS evaluations are

based on Appendix K requirements.

Before this revision, the opening

sentence of Appendix K specified that a

power level of 102 percent be assumed

when conducting ECCS analyses.

Licensees have proposed using

instrumentation that would reduce the

uncertainties associated with

measurement of reactor power when

compared with existing methods of

power measurement. This development

could justify a reduced margin between

the licensed power level and the power

level assumed for ECCS evaluations.

This final rule amends this provision in

Appendix K and allows licensees the

option of using a value lower than 102

percent of licensed power in their ECCS

analyses where justified.

Several licensees have expressed

interest in using updated feedwater flow

measurement technology discussed later

in ‘‘Calorimetric Uncertainty and

Feedwater Flow Measurement’’ as a

basis for seeking exemptions from the

Appendix K power level requirement

and to implement power uprates. One

licensee, TXU Electric Company,

obtained an exemption from the

Appendix K requirement for Comanche

Peak Units 1 and 2 as well as an

increase in licensed power based, in

part, on more accurate feedwater flow

measurement capability. The prospect

of additional exemption requests from

other licensees provides the impetus for

the final rule.

The objective of this rulemaking is to

reduce an unnecessarily burdensome

regulatory requirement. Appendix K

was originally issued to ensure an

adequate performance margin of the

ECCS in the event a design-basis LOCA

were to occur. The margin is provided

by conservative features and

requirements of the evaluation models

and by the ECCS performance criteria.

The original regulation did not require

that the power measurement uncertainty

be demonstrated, but rather mandated a

2-percent margin. The final rule allows

licensees to justify a smaller margin for

power measurement uncertainty.

Because there will continue to be

substantial conservatism in other

Appendix K requirements, sufficient

margin to ECCS performance in the

event of a LOCA will be preserved,

which is the underlying purpose of

Appendix K. The final rule does not

significantly affect plant risk, as

discussed in the section entitled, ‘‘ECCS

Evaluation Conservatism.’’

Another objective is to avoid

unnecessary exemption requests. A

licensee has obtained an exemption

from the 2-percent margin requirement

in 10 CFR part 50, Appendix K. The

final rule eliminates the need for

licensees to obtain exemptions.

The final rule gives licensees the

option of applying a reduced margin

between the licensed power level and

the assumed power level for ECCS

evaluation, or maintaining the current

margin of 2-percent power. As

discussed in the section entitled ‘‘ECCS

Evaluation Conservatism,’’ the NRC has

concluded that the 2 percent power

margin requirement in the original rule

appeared to be based solely on

considerations associated with power

measurement extant at the time of the

original ECCS rulemaking. The original

rule unnecessarily restricted operation

for licensees that can show that the

uncertainties associated with power

measurement instrumentation errors are

less than 2 percent.

This amendment gives licensees the

opportunity to use a reduced margin if

they determine that there is a sufficient

benefit. Licensees may apply the margin

to gain benefits from operation at higher

power, or the margin could be used to

relax ECCS-related technical

specifications (e.g., pump flows).

Another potential benefit could be in

modifying fuel management strategies

(e.g., possibly by altering core power

peaking factors). However, the final

rule, by itself, does not allow increases

in licensed power levels. Because

licensed power level for a plant is a

technical specification limit, proposals

to raise the licensed power level must

be reviewed and approved under the

license amendment process. The license

amendment request should include a

justification of the reduced power

measurement uncertainty and the basis

for the modified ECCS analysis,

including the justification for reduced

power measurement uncertainty, should

then be included in documentation

supporting the ECCS analysis (see

Section-by-Section Analysis).

As licensees apply the final rule and

the NRC gains experience reviewing

related license amendment requests, the

NRC will consider the need for specific

guidance to help licensees appropriately

account for power measurement

uncertainty in safety analyses. In the

absence of specific guidance, the NRC

expects that power uprate amendment

requests based on this amendment to

the regulations will address the

suitability of non-LOCA analyses for

operation at proposed higher power

levels. Licensees can refer to available

instrumentation guidance such as the

Instrument Society of America Standard

ISA 67.04, 1982, ‘‘Safety-Related

Instrumentation Used in Nuclear Power

Plants,’’ and NRC Regulatory Guide

1.105, Revision 2, ‘‘Instrument Setpoints

for Safety-Related Systems.’’

Conservatisms in Appendix K ECCS

Evaluation Model

Appendix K defines conservative

analysis assumptions for ECCS

performance evaluations during designbasis LOCAs. Large safety margins are

provided by conservatively selecting the

ECCS performance criteria as well as

conservatively establishing ECCS

calculational requirements. The major

analytical parameters and assumptions

that contribute to the conservatisms in

Appendix K are set forth in sections A

through D of the rule: (A) ‘‘Sources of

Heat During the LOCA’’ (the 102-

percent power provision is a key factor);

(B) ‘‘Swelling and Rupture of the

Cladding and Fuel Rod Thermal

Parameters;’’ (C) ‘‘Blowdown

Phenomena;’’ and (D) ‘‘Post-Blowdown

Phenomena: Heat Removal by ECCS.’’ In

each of these areas, several assumptions

are typically used to ensure substantial

conservatism in the analysis results. For

Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations 34915

1This statement in the SOC was taken unchanged

from section I of the Commission’s ECCS decision.

See CLI–73–39, 6 AEC 1085, 1093–94 (December

28, 1973).

instance: under ‘‘Sources of Heat During

the LOCA,’’ decay heat is modeled on

the basis of an American Nuclear

Society standard with an added 20-

percent penalty, and the power

distribution shape and peaking factors

expected during the operating cycle are

chosen to yield the most conservative

results. In ‘‘Blowdown Phenomena,’’ the

rule requires use of the Moody model

and the discharge coefficient that yields

the highest peak cladding temperature.

‘‘Post-Blowdown Phenomena; Heat

Removal by the ECCS,’’ requires that the

analysis assume the most damaging

single failure of ECCS equipment.

One of several conservative

requirements in section A of the original

Appendix K was to assume that the

reactor was operating at 102 percent

power when the LOCA occurred ‘‘to

allow for such uncertainties as

instrumentation error * * *.’’

(Appendix K, section I.A., first sentence,

emphasis added). The phrase, ‘‘such

as,’’ suggested that the two percent

power margin was intended to address

uncertainties related to heat source

considerations beyond instrument

measurement uncertainties. However,

the basis for the required assumption of

102 percent power (2 percent power

margin) does not appear to be contained

in the rulemaking record for the ECCS

rules, 10 CFR 50.46 and Appendix K.

These rules were adopted in 1974 (39

FR 1001; January 4, 1974), and were

preceded by a formal rulemaking

hearing which ultimately resulted in a

Commission decision on the proposed

rulemaking, CLI–73–39, 6 AEC 1085

(December 28, 1973). Neither the

statement of considerations (SOC) for

the final rule nor the Commission

decision appear to provide specific basis

for the required assumption of 102

percent power.

The SOC for the January 4, 1974, final

rule discusses the 102 percent power

assumption in general terms, and does

not mention instrumentation

uncertainty:

The Commission believes that the

implementation of the new regulations will

ensure an adequate margin of performance of

the ECCS should a design basis LOCA ever

occur. This margin is provided by

conservative features of the evaluation

models and by the criteria themselves. Some

of the major points that contribute to the

conservative nature of the evaluations and

the criteria are as follows:

(1) Stored heat. The assumption of 102

percent of maximum power, highest allowed

peaking factor, and highest estimated thermal

resistance between the UO2 and the cladding

provides a calculated stored heat that is

possible but unlikely to occur at the time of

a hypothetical accident. While not

necessarily a margin over the extreme

condition, it represents at least an

assumption that an accident happens at a

time which is not typical. 39 FR at 1002 (first

column).1

Thus, while the pre-accident power

level assumption is connected with the

modeling of the rate of heat generation

after the LOCA occurs, a clear basis for

the 102 percent assumed power level

requirement is not provided, nor does

the SOC explain whether there are other

uncertainties besides instrumentation

uncertainties for which the 102 percent

assumed power level is intended to

compensate.

The Commission’s decision in the

ECCS rulemaking hearing also does not

explain whether the 102 percent

assumed power level was intended to

address uncertainties other than

instrumentation uncertainties. Section I

of the Commission decision was the

basis for the SOC discussion on the 102

percent assumed power level (see 6 AEC

at 1093–94). Section III. A. of the

Commission’s decision, ‘‘Required and

Acceptable Features of the Evaluation

Model,’’ does not offer a detailed

technical basis for the power level

chosen, but instead uses the language

ultimately adopted in the original

Appendix K rule:

For the heat sources listed in paragraphs 1

to 4 below it shall be assumed that the

reactor has been operating continuously at a

power level at least 1.02 times the licensed

power level (to allow for such uncertainties

as instrumentation error), with the maximum

peaking factor allowed by the technical

specifications (6 AEC at 1100).

Thus, the Commission’s decision does

not shed further light on the basis for

the 102 percent assumed power level,

nor whether the Commission had in

mind uncertainties other than those

associated with the instrumentation for

measurement of power level.

NRC review of the ECCS rulemaking

hearing record did not disclose

presentations relating to quantification

of power measurement uncertainties, or

the magnitude of other uncertainties

that the 102 percent assumed power

level may have been intended to

address. The Commission decision

(CLI–73–39, 6 AEC 1085, December 28,

1973) cited three documents in the

rulemaking hearing record.

The first, cited in the Commission

decision as Exhibit 1113, was

‘‘Supplemental Testimony of the AEC

Regulatory Staff on the Interim

Acceptance Criteria for Emergency Core

Cooling Systems for Light-Water Cooled

Power Reactors’’ (filed October 26,

1972). In section 10 of the document,

stored energy in the fuel was

considered, specifically the expected

power distributions in fuel rods. The

102-percent power analysis requirement

is not discussed.

The second item, cited in the

Commission decision as Exhibit 1137

was ‘‘Redirect and Rebuttal Testimony

of Dr. Donald H. Roy on Behalf of

Babcock & Wilcox,’’ (October 26, 1972)

in which the characteristic of the decay

heat release following reactor shutdown

was discussed. In this document, the

102-percent assumption is associated

with the predicted decay heat

generation rate. The over-power

condition is associated with a ‘‘designbasis maneuvering operation,’’ but the

basis for the value of power chosen for

the analysis (i.e., 102 percent) is not

disclosed.

Finally, in the ‘‘Concluding Statement

of Position of the Regulatory Staff—

Public Rulemaking Hearing on:

Acceptance Criteria for Emergency Core

Cooling Systems for Light-Water Cooled

Nuclear Power Reactors,’’ April 16, 1973

(the Concluding Statement), the power

level assumption is included as part of

the proposed rule itself. The proposed

rule language clearly states that the

power level assumption is to ‘‘allow for

instrumentation error.’’ The term ‘‘such

as’’ does not appear here. It is unclear

when or why the proposed language in

this regard was changed to its current

form. The power level assumption is

mentioned again in the Concluding

Statement indirectly in association with

power level changes before the LOCA

and the effect on decay heat generation.

But it is discussed most directly with

regard to initial stored energy in the

fuel. In the discussion on stored energy,

the 102-percent assumption is attributed

to ‘‘uncertainties inherent in the

measurement of the operating power

level of the core’’ (page 144 of the

Concluding Statement). Reasons for

choosing 102-percent as the value are

not discussed.

When Appendix K was first issued, as

is the case today, the thermal power

generated by a nuclear power plant was

determined by steam plant calorimetry,

which is the process of performing a

heat balance around the nuclear steam

supply system (called a calorimetric).

The heat balance depends upon

measurement of several plant

parameters, including flow rates and

fluid temperatures. The differential

pressure across a venturi installed in the

feedwater flow path is a key element in

the calorimetric measurement.

Licensees have proposed using

instrumentation other than a venturiVerDate 11<MAY>2000 14:49 May 31, 2000 Jkt 190000 PO 00000 Frm 00003 Fmt 4700 Sfmt 4700 E:\FR\FM\01JNR1.SGM pfrm03 PsN: 01JNR1
34916 Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations

based system to obtain feedwater flow

rate for calorimetrics. The lower

uncertainty associated with the new

instrumentation is information that was

apparently not available during the

original Appendix K rulemaking.

In view of the regulatory history for

Appendix K, the Commission now

believes that the 2-percent margin

embodied in the requirement for a 102-

percent assumed power level in

Appendix K was based solely on

uncertainties associated with the

measurement of reactor power level.

Reduction in 102 Percent Assumed

Power Level

The Commission believes that other

requirements of Appendix K modeling

contain substantial conservatisms of

much greater magnitude than the 2

percent margin embodied in the

requirement for a 102 percent assumed

power level. This point was discussed

in ‘‘Conservatisms in Appendix K ECCS

Evaluation Model,’’ above.

The Commission is also aware of new

information gained since the 1974

rulemaking which shows that the

Appendix K model contains additional

conservatisms not recognized in 1974.

Evidence from experiments designed to

simulate LOCA phenomena suggest that

these conservatisms added hundreds of

degrees Fahrenheit to the prediction of

peak fuel cladding temperature than

would actually occur during a LOCA.

The significant conservatism was

necessary when the rule was written

because of a lack of experimental

evidence at that time with respect to the

relative effects of analysis input

parameters, including pre-accident

power level. Since that time, there has

been substantial additional research on

LOCA. NUREG–1230, ‘‘Compendium of

ECCS Research for Realistic LOCA

Analysis,’’ December 1988, contains the

technical basis for improved

understanding of LOCA progression and

ECCS evaluation gained after the ECCS

rule was issued. The NUREG includes a

discussion of the basis for uncertainties

in detailed fuel bundle power

calculations as part of the consideration

of overall calculational uncertainty

inherent in best-estimate evaluations.

Chapters 7 and 8 of the NUREG include

consideration of the changes in licensed

power level that could result from

application of best-estimate evaluation

methods. The discussion includes an

estimated sensitivity of predicted peak

clad temperature (PCT) associated with

changes in pre-accident power level.

From that estimate, the NRC expects

peak cladding temperature changes of

approximately 15 °F to result from 1-

percent changes in plant power level

that could result from the final rule.

In view of: (i) Substantial

conservatisms known in 1974 that were

embodied in the Appendix K

requirements for ECCS evaluations; (ii)

new information developed since the

1974 rulemaking which shows

additional conservatism in the

Appendix K modeling requirements

beyond that understood by the

Commission when it adopted the 1974

rule; and (iii) the relative insensitivity of

the calculated clad temperatures to

assumed power level, the Commission

concludes that it is acceptable to allow

a reduction in the currently-required

102 percent power level assumption if

justified by the actual power level

measurement instrumentation

uncertainty. Accordingly, the

Commission is amending the Appendix

K requirement for an assumed 102

percent power level. This amendment

allows a licensee to use an assumed

power level of less than 102 percent (but

not less than 100 percent), if the

licensee has determined that the

uncertainties in the measurement of

core power level justifies the reduced

margin.

Calorimetric Uncertainty and

Feedwater Flow Measurement

The NRC staff has approved an

exemption to the 102-percent power

level requirement for Comanche Peak

Units 1 and 2. The basis for the action

is application of upgraded feedwater

flow measurement technology at the

plant. As indicated, the prospect of

additional licensees requesting similar

action has prompted the final rule.

Other methods, systems, or analyses

could be used as the basis for

demonstrating reduced power

measurement uncertainty.

In most nuclear power plants,

operators obtain a continuous indication

of core thermal power from nuclear

instruments that provide a measurement

of neutron flux. The nuclear

instruments must be periodically

calibrated to counteract the effects of

changes in flux pattern, fuel burnup,

and instrument drift. Steam plant

calorimetry, which is the process of

performing a heat balance around the

nuclear steam supply system (called a

calorimetric), is used to determine core

thermal power and is the basis for the

calibration. The differential pressure

across a venturi installed in the

feedwater flow path is a key element in

the calorimetric measurement. Some

plants use this calorimetric value

directly to indicate thermal power; the

nuclear instruments are used as

anticipatory indicators for transients

and for reactivity adjustments made

with the control rods.

The system in use at Comanche Peak

Units 1 and 2 is the Leading Edge

Flowmeter (LEFM), manufactured by

Caldon, Inc. The LEFM system is an

ultrasonic flow meter that measures the

transit times of pulses traveling along

parallel acoustic paths through the

flowing fluid. LEFM technology has

been employed in non-nuclear

applications, such as petroleum,

chemical, and hydroelectric plants for

several years. This operating experience

will provide reliability data,

supplementing data from nuclear

applications. Additional information on

the Comanche Peak Appendix K

exemption and on the Caldon, Inc.

LEFM system appears in safety

evaluations issued by the NRC staff on

March 8, 1999, and May 6, 1999.

The NRC issued a safety evaluation on

March 20, 2000, on the ABB

Combustion Engineering ultrasonic

flow-measuring system known as

Crossflow. The Crossflow system is

expected to be part of a licensee

amendment request for power uprate in

the near future.

Public Comment

In the proposed rulemaking (64 FR

53270; October 1, 1999), the NRC sought

comments from the public on four

issues related to the revision of

Appendix K. The NRC received

comments from four utility companies,

the Nuclear Energy Institute (NEI), and

Caldon, Inc., manufacturer of the LEFM

system. All of the commenters

supported the proposed rule. NEI and

Caldon offered comments on the four

issues that the Commission included in

the proposed rule. NEI and the New

York Power Authority commented on

several other issues as well.

The issues that accompanied the

proposed rule were:

1. The current rule states that the

required 2-percent analysis margin is to

account for ‘‘such uncertainties as

instrumentation error * * *.’’

(emphasis added). This suggests that the

2-percent margin was intended to

account for other sources of uncertainty

in addition to instrumentation error.

However, explicit documentation of the

basis for the value of the margin does

not appear to be contained in the

rulemaking record for the original 1974

ECCS rulemaking. The Commission was

interested in whether there were other

sources of uncertainty, relevant to

sources of heat following a LOCA, that

should be considered when licensees

seek to reduce the margin in the

Appendix K requirement for assumed

power.

Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations 34917

As discussed in the section entitled,

‘‘Conservatisms in Appendix K ECCS

Evaluation Model,’’ the Commission

considered the rulemaking historical

record for Appendix K and concluded

that instrument uncertainty was likely

the only source of uncertainty that was

to be accounted for by the 2-percent

margin. NEI and Caldon have not

identified other sources of uncertainty,

relevant to sources of heat following a

LOCA, that are connected with the

power level assumption.

2. Were there rulemaking alternatives

to the proposed rule that were not

considered in the regulatory analysis?

The Commission considered

rulemaking alternatives in the

accompanying regulatory analysis. The

alternatives were: (i) No rule change; (ii)

removal of the 102 percent requirement

while requiring justification of a power

level margin; (iii) the approach taken in

the amended rule to maintain the 102

percent requirement and offer the

option to reduce the margin; (iv)

elimination of the power level margin;

and (v) broad revision of Appendix K

addressing all analysis requirements.

Additional alternatives were not

identified in the comments received for

the proposed rule.

3. What criteria should be used for

determining whether a proposed

reduction in the 2 percent power margin

has been justified, based upon a

determination of instrumentation error?

For example, should a demonstrated

instrumentation error of 1 percent in

power level be presumptive of an

acceptable reduction in assumed power

margin of 1 percent?

The comments from NEI on this point

emphasized that any criteria developed

to evaluate proposed reductions in

ECCS analysis power margin should be

based only on the instrumentation error

associated with power measurement.

NEI said that the conservatism inherent

in the ECCS analysis requirements

embodied in Appendix K provide

sufficient margin to maintain safety so

that instrumentation uncertainty should

be the only basis for the power level

assumption. The comments also stated

that the overall impact on safety should

be considered and that degradation in

safety should not be allowed.

The Commission agrees that the main

criteria determining the suitability of

proposed power level margin reductions

should be the details associated with

uncertainties in power level

measurement. The Commission also

agrees that the overall impact on plant

safety should be considered, preferably

in a risk-informed manner. However,

the commenter contended that a lower

probability of exceeding the analyzed

power level translates to an overall

improved level of safety at a facility.

The Commission does not necessarily

equate a lower probability of exceeding

an analysis limit with improved safety

for facilities that obtain approvals to

increase reactor thermal power or make

other changes based on the amendment.

For example, when plants obtain power

uprates in conjunction with the

relaxation in the amended rule, other

factors come into play that may reduce

the overall margin of safety, albeit

probably only slightly for the small

power increases anticipated with the

amendment. Such changes in safety

margin, if small and controlled, can be

acceptable in light of other substantial

conservatisms or associated risk-related

information.

Caldon offered detailed comments on

this issue. Their comments went beyond

general instrumentation uncertainty

considerations by proposing a list of

criteria that appeared to be based on

application of the LEFM to power

measurement at a plant. Although the

Commission considers the criteria

provided by Caldon to be helpful, the

Commission is not yet prepared to

formalize any criteria for evaluating

reductions in the power level margin for

ECCS analysis. The safety evaluations

associated with the Appendix K

exemption and power uprate for

Comanche Peak granted to TXU Electric

Company set forth basic review criteria,

including many of those proposed by

Caldon. In those reviews, the NRC staff

referred to available instrumentation

guidance such as the Instrument Society

of America Standard ISA 67.04, 1982,

‘‘Safety-Related Instrumentation Used in

Nuclear Power Plants,’’ and NRC

Regulatory Guide 1.105, Revision 2,

‘‘Instrument Setpoints for Safety-Related

Systems.’’

The NRC staff intends to gain further

experience with licensee proposals that

pursue the relaxation offered by the

amendment before deciding whether a

regulatory guide providing detailed

acceptance criteria needs to be

developed. Licensee proposals may

involve use of advanced flow

measurement systems or other

approaches to determine the level of

power measurement uncertainty and to

reduce it. However, the Commission

does not believe that generic acceptance

criteria should be too closely based on

any particular measurement technology

or analysis method.

4. How should the rule address cases

in which licensees determine that

power measurement instrument error is

greater than 2 percent?

Both NEI and Caldon offered

comments on this issue. Caldon

maintained that current regulatory

processes provide a sufficient basis for

dealing with such situations. NEI

recommended that licensees should

conduct Appendix K ECCS evaluations

at rated thermal power level plus the

value of power measurement

uncertainties, regardless of the

magnitude of the uncertainty. The

comments clearly stated that this

position also applies for uncertainties

determined to be greater than 2 percent.

NEI considered the need for licensees to

ensure that safety analyses are valid for

their facility. According to NEI, if the

required margin for power level

measurement were found to be

insufficient to account for actual

uncertainty levels, then licensees must

take appropriate action, including

lowering the operating power level. NEI

offered alternatives for licensees to

accommodate uncertainties above 2

percent, including demonstration that

the PCT margin for a facility could

accommodate greater-than-expected

uncertainty. Also, NEI indicated that

other conservatisms in Appendix K

methodologies could be applied to

‘‘offset’’ the excessive power

measurement uncertainty.

The Commission agrees that licensees

who find that the power measurement

uncertainty for their facilities is greater

than expected should take action to

ensure that their plant is operated

within the assumptions used in safety

analyses. This follows from the

requirement in 10 CFR 50 Appendix B,

section III, ‘‘Design Control.’’ The

Appendix B requirement states that

design control measures will be applied

to items such as accident analyses, and

that design changes shall be subject to

design control measures. Therefore,

licensees must take action if the power

measurement uncertainty is greater than

typically expected or as determined in

a plant-specific analysis. The expected

magnitude of uncertainty at a facility

could be the 2-percent margin that is

preserved in the final rule, or it could

be based on a plant-specific analysis

supporting a smaller value. As already

considered, the basis for the value in the

rule is not clearly illuminated in the

rulemaking history of Appendix K.

However, the Commission believes that

the Appendix K value represents a

typical value for power measurement

uncertainty, unless demonstrated

otherwise for a particular facility.

The Commission does not believe that

it is necessary to allow application of

safety margins based on other

conservative factors in an Appendix K

ECCS evaluation to offset excessive

uncertainties discovered in power

measurement for a plant. By proposing

34918 Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations

to use safety margin ‘‘offsets’’ to justify

higher-than-expected power

measurement uncertainties, NEI is

proposing an alternative to Appendix K

ECCS evaluation methods already

permitted by § 50.46. The Commission

considers the available analysis

alternatives offered by § 50.46 (i.e.,

those based on Appendix K and the socalled best estimate methods) to offer

sufficient flexibility to licensees without

introducing large complexities to the

review and approval process that could

be anticipated if Appendix K were to be

applied in a ‘‘piecemeal’’ fashion.

The Commission originally instituted

the ECCS evaluation requirements with

the understanding that substantial

conservatisms existed. Later, the relative

contributions of various conservative

factors were estimated on a largely

generic basis to demonstrate the

feasibility of best-estimate evaluations.

However, when the revisions to § 50.46

were considered in 1988, the

Commission deliberately maintained

two distinct options: (i) Licensees could

use the method defined by Appendix K;

or (ii) they could develop a bestestimate approach. The alternatives

discussed in the NEI comment can be

accommodated by a licensee using the

best-estimate option offered by § 50.46,

rather than applying Appendix K in a

‘‘piecemeal’’ fashion.

On the basis of the ‘‘best-estimate’’

alternative to Appendix K requirements

available in § 50.46, the Commission

takes the position that Appendix K

requirements should not be applied in

a ‘‘piecemeal’’ fashion, as discussed in

the NEI comment. Rather than searching

for customized adjustments to

Appendix K requirements, licensees

should develop a ‘‘best-estimate’’

method, as permitted in § 50.46. The

Commission position does not present

licensees with an onerous burden.

Licensees discovering that actual power

measurement uncertainty at their plant

is greater than the uncertainty assumed

in safety analysis can take corrective

action to address the problem while

continuing plant operation. For

example, plant power level may be

reduced while the problem is addressed.

Therefore, in the final rule the

Commission has not adopted the NEI

approach of applying offsetting

uncertainties.

The comments received from NEI

addressed four additional areas:

1. Uncertainties from additional heat

sources. NEI commented that utilities

would be able to use the amended rule

to reduce the decay heat input used in

Appendix K evaluations. NEI proposed

that licensees could use the power

measurement uncertainty to, ‘‘ensure

that the expected decay heat bounds the

full rated plant power plus the

uncertainty value.’’

The NEI comment expands the scope

of the proposed revision to Appendix K,

bringing into consideration decay heat

uncertainty, which is a separate analysis

requirement in the rule. The

Commission agrees that the decay heat

level used in the Appendix K analysis

could be reduced commensurate with a

lower assumed power level. However,

the reduced power level assumption

must be justified by an acceptable

analysis of the power measurement

uncertainty. Also, the decay heat level

used in the analysis must continue to

meet the requirement in Appendix

K(I)(A)(4), ‘‘Fission Product Decay.’’

Discussion of the uncertainty involved

with decay heat value required by

Appendix K(I)(A)(4) is beyond the scope

of this rulemaking. Licensees who wish

to address the uncertainty of the decay

heat level in their ECCS analysis should

develop a ‘‘best-estimate’’ method

which addresses uncertainties of all of

the ECCS analysis parameters.

2. Consistency among NRC

documents. NEI pointed out that other

Commission documents besides

Appendix K contain the 1.02 power

level multiplier. In the regulatory

analysis accompanying the rule, the

Standard Review Plan sections and

Regulatory Guide 1.49 are listed as part

of the current regulatory framework

considered during the rulemaking.

The NRC staff agrees with the

comment that changes to guidance

documents may be necessary and will

make the necessary revisions to these

documents to maintain consistency with

the amended rule.

3. Requirement for upgrade to

feedwater flow measurement. NEI

commented that the proposed rule

appeared to be based upon application

of upgraded feedwater flow technology.

NEI recommended that the rule or

associated guidance make clear that

availability of the relaxation offered by

the final rule is not restricted to

licensees applying upgraded flow

measurement technology.

The preamble for the proposed rule

does indeed discuss application of

improved flow measurement

technology. This discussion is

appropriate because this new

technology is the impetus for the

exemption granted to one licensee and

is a key justification for the Commission

action in amending the current rule. In

the section, ‘‘Calorimetric Uncertainty

and Feedwater Flow Measurement,’’ the

Commission pointed out that methods

other than application of improved flow

measurement technology could be used

as the basis for demonstrating reduced

power measurement uncertainty. Also,

in its discussion of the Caldon

comments on issue number 3, the

Commission acknowledged that licensee

proposals may involve use of advanced

flow measurement systems or other

approaches. To prevent

misinterpretation of the rule, the

Section-by-Section analysis has been

modified to reiterate that other methods

not considered in the rulemaking could

be used to justify a reduced power

measurement uncertainty allowance.

Although various approaches to reduce

the uncertainty involved with PCT

calculation may be used, the only

uncertainty considered under this

amendment is that associated with

power level measurement.

4. Reportability under 10 CFR

50.46(a)(3). NEI cited the Section-bySection analysis of the proposed rule,

where the Commission stated that,

‘‘estimated changes in ECCS

performance due to final analysis inputs

are reported under section 50.46 (a)(3),

at least annually.’’ NEI recommended

clarification of the statement to reflect

an interpretation of § 50.46 so as to

relate only to evaluation model

parameters, but not to plant design

parameters. NEI contended that plant

parameters change from cycle to cycle

and that changes in PCT caused by plant

specific input parameter changes to

design information fall outside the

scope of reportability under 10 CFR

50.46(a)(3).

Although the Commission accepts

that the results of ECCS evaluations

could change as a result of cycle specific

variations in model inputs, the

Commission does not agree with NEI on

this point. In their comment, NEI drew

a distinction between design inputs and

model inputs to ECCS evaluations. The

amended rule does not change the

reporting requirements of 10 CFR 50.46

for changes to ECCS evaluations. The

regulations are clear on the definition of

an ECCS evaluation model and when

reports are required. 10 CFR 50.46 (c)(2)

defines ECCS evaluation models and

provides a list of the elements

including, ‘‘one or more computer

programs and all other information

necessary for application of the

calculational framework to a specific

LOCA, such as * * * values of

parameters, and all other information

necessary to specify the calculational

procedure.’’ In other words, the ECCS

evaluation model is comprised of the

computer code or codes, the input

parameters (including plant-specific

design parameters), and the

calculational results. The Commission

should be informed as described in 10

Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations 34919

CFR 50.46(a)(3) when even a relatively

small change to the calculational

framework is made, especially when the

PCT result is affected. As discussed in

the statement of considerations to the

September 16, 1988, final rule (53 FR

35996), the Commission needs to be

cognizant of such changes to be able to

confirm licensee or vendor assessments

of the significance of the changes and to

ensure that approved models continue

to be used.

10 CFR 50.46 (a)(ii) contains an

unambiguous requirement that changes

to the ECCS evaluation must be reported

at least annually: ‘‘For each change to or

error discovered in an acceptable

evaluation model or in the application

of such a model that affects the

temperature calculation, the applicant

or licensee shall report the nature of the

change or error and its estimated effect

on the limiting ECCS analysis to the

Commission at least annually as

specified in § 50.4.’’ Therefore, on the

basis of the definition of an evaluation

model in § 50.46, the Commission does

not accept the distinction made by NEI

between ‘‘model parameters’’ and

‘‘design parameters.’’ Based on the

requirements of § 50.46, changes to the

ECCS evaluation model under the

amended Appendix K rule which affect

the temperature calculation must be

reported at least annually.

The comments from one licensee, the

New York Power Authority (NYPA),

considered two areas not already

discussed:

1. Other potential benefits. NYPA

commented that licensees could seek

benefits other than increasing licensed

power under the amended rule. The

commenter offered two examples of

such benefits—revised containment

analyses conducted at power levels

below 102 percent power and relaxation

of operating restrictions on ultimate

heat sink temperatures.

The Commission agrees that licensees

could request the relaxation offered by

the amended rule while not pursuing a

power level increase. In the Background

section the Commission recognized that

other benefits are available to licensees

and that power level increase is just one

option. The examples offered by the

NYPA comments may be suitable to a

licensee, depending on plant

characteristics and plant-specific safety

analyses.

2. Changes to technical specifications.

NYPA interpreted statements in the

proposed rule to suggest that licensees

pursuing the relaxation offered in the

amendment would need to change their

plant technical specifications to include

a limiting condition for operation for

new feedwater flow instrumentation.

Further, the comments suggested that

clarification was needed to address

when license amendments were

required for changes associated with the

rule.

In the Section-by-Section Analysis,

the Commission discusses technical

specification modifications that might

be necessary when a power

measurement uncertainty reduction is

used in safety analyses. Typically, when

an ECCS methodology is changed, a

revision is made to the technical

specification list of references

associated with plant safety analysis

methods. Technical specifications for

nuclear power plants do not contain

explicit requirements for feedwater flow

instrumentation. The Commission does

not believe that technical specification

requirements for feedwater flow

instruments are necessary for licensees

to use the relaxation offered by the

amended rule. Clarification regarding

this point has been added to the

Section-by-Section Analysis.

Section-by-Section Analysis

Appendix K to Part 50—ECCS

Evaluation Models (I)(A)—Sources of

Heat During the LOCA

This section is amended by removing

words from the first sentence in the

section to specifically associate the

power level requirement with

instrumentation error, and by adding a

sentence immediately following the first

sentence in the section. The new

sentence indicates that licensees may

assume a power level lower than 102

percent, but not less than 100 percent,

if the proposed lower alternative value

can be shown to account for core

thermal power measurement

instrumentation uncertainty. Licensee

proposals may involve use of advanced

flow measurement systems or other

approaches to determine the level of

power measurement uncertainty and to

support reduction of the power level

assumption. Only the uncertainty

associated with power level

measurement is considered in this

amendment.

Appendix K, part II (1)(a) requires that

the values of analysis parameters or

their basis be sufficiently documented

to allow NRC review. The requirement

applies to all analysis input parameters,

including those related to other plant

instrumentation, such as temperature

and pressure. Changes to other inputs

are documented in the same manner as

the power measurement uncertainty

would be documented under the final

rule. NRC review and approval is not

needed to change a parameter in an

approved ECCS evaluation model unless

the change is associated with technical

specification or license condition

modfications, or a final safety analysis

report change not covered by § 50.59,

‘‘Changes, tests and experiments.’’

Estimated changes in ECCS performance

due to revised analysis inputs are

reported under § 50.46 (a)(3), at least

annually. As discussed in the Statement

of Considerations for a final rule

amending Appendix K (53 FR 36001;

September 16, 1988), the annual reports

keep NRC apprised of changes. This

should ensure that the NRC staff can

evaluate a licensee’s assessment of the

significance of changes and maintain

cognizance of modifications made to

NRC-approved evaluation models. The

licensee must include revised

parameters and other changes in the

ECCS evaluation model as required by

§ 50.46 (a)(3) when a single change or an

accumulation of changes is expected to

affect peak cladding temperature by

50°F or more. The basis for the revised

analysis parameter (i.e., the assumed

power level) should be included in

documentation of the evaluation model,

as required by Appendix K, Part II (1)(a).

Licensees could take advantage of the

amended rule without a change to

technical specifications or to the plant

license by simply updating the ECCS

analysis and following the reporting

requirements of § 50.46. However, in

most cases the NRC expects that the

analysis supporting the power

measurement uncertainty, as well as the

description of the relevant

instrumentation and associated plantspecific parameters involved in the

uncertainty analysis, would be

submitted for NRC review and approval

before being used. These requests are

expected because most licensees have

adopted Generic Letter 88–16, ‘‘Removal

of Cycle-Specific Parameter Limits from

Technical Specifications.’’ The generic

letter provided guidance for licensees to

transfer cycle-specific parameters from

their technical specifications to a Core

Operating Limits Report (COLR).

Licensees following the generic letter

guidance added an administrative

requirement to their technical

specifications that specifically identifies

NRC-reviewed and approved methods

used to determine core operating limits

(e.g., topical reports). Because a number

of core operating limits are based on

LOCA analysis results, ECCS evaluation

methods are included in the technical

specification list. Therefore, most

licensees opting to use the relaxation in

the final rule will need to amend

technical specifications to include a

reference to an NRC-approved topical

report that includes the uncertainty

34920 Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations

analysis justifying reduced power

measurement uncertainty. However, a

technical specification requirement

specifically related to feedwater flow

measurement system operability is not

needed.

An additional technical specification

consideration for licensees pursuing

changes based on the final rule could

involve nuclear instrument (NI)

requirements. Existing plant technical

specifications include surveillance

requirements to calibrate the power

range NIs based on the calorimetric

measuring reactor thermal power. The

NIs provide the indication of reactor

power used as an input for safety

systems. Licensees obtaining the

relaxation offered in the final rule are

expected to change some operating

parameter of the plant, whether it be

power level, required ECCS flow, etc. By

incorporating the justification of

reduced uncertainty in power

measurement in the basis for their ECCS

analysis, licensees would be placing a

condition on an input to the

calorimetric. The NI calibration required

by the plant licensee would then be

based on a calorimetric assuming the

reduced power measurement

uncertainty. If, for some reason, during

the course of plant operation the

reduced uncertainty did not apply (e.g.,

the new feedwater flow meter was no

longer operating), the calorimetric

would no longer be a valid source of

calibration for the NIs. Licensees would

need to take action to maintain

compliance with their technical

specification, for example, by using an

alternate input to the calorimetric. The

power measurement uncertainties

associated with the alternate input

would then apply and the plant would

need to adjust its operating condition

(possibly lower its operating power

level) to satisfy the final rule and to

maintain the validity of applicable

safety analyses. A change to technical

specifications for NIs is not required in

this situation.

Referenced Documents

Copies of GL–88–16, and CLI–73–39,

and ‘‘Supplemental Testimony of the

AEC Regulatory Staff on the Interim

Acceptance Criteria for Emergency Core

Cooling Systems for Light-Water Cooled

Power Reactors,’’ and ‘‘Redirect and

Rebuttal Testimony of Dr. Donald H.

Roy on Behalf of Babcock & Wilcox,’’

and ‘‘Concluding Statement of Position

of the Regulatory Staff—Public

Rulemaking Hearing on: Acceptance

Criteria for Emergency Core Cooling

Systems for Light-Water Cooled Nuclear

Power Reactors,’’ and NRC safety

evaluations are available for inspection

and copying for a fee at the NRC Public

Document Room, 2120 L Street, NW.

(Lower Level), Washington, DC. GL–88–

16 is also available via the Internet at

http://www.nrc.gov/NRC/GENACT/GC/

index.html#GL.

NUREG–1230 is available from the

Superintendent of Documents, U.S.

Government Printing Office, Post Office

Box 37082, Washington, DC 20013–7082

or from the National Technical

Information Service, Springfield, VA

22161.

Voluntary Consensus Standards

The National Technology Transfer Act

of 1995, Pub. L. 104–113, requires that

Federal agencies use technical standards

that are developed or adopted by

voluntary consensus standards bodies

unless the use of such a standard is

inconsistent with applicable law or

otherwise impractical. In this final rule,

the NRC provides holders of operating

licenses for nuclear power plants the

option of reducing the assumed reactor

power level used in ECCS evaluations.

This action constitutes a modification to

an existing government-unique

standard, 10 CFR part 50, Appendix K

issued by the NRC on January 4, 1974.

The NRC is not aware of any voluntary

consensus standard that could be

adopted instead of the governmentunique standard. The NRC considered

using a voluntary consensus standard.

However, an appropriate standard was

not identified.

Finding of No Significant

Environmental Impact: Availability

The NRC has determined under the

National Environmental Policy Act of

1969, as amended, and the NRC’s

regulations in subpart A of 10 CFR part

51, that this regulation is not a major

Federal action significantly affecting the

quality of the human environment and,

therefore, an environmental impact

statement is not required.

The action is likely to result in

relatively small changes to ECCS

analyses or to the licensed power of

nuclear reactor facilities. The NRC staff

expects that no significant

environmental impact will result from

the final rule, because licensee actions

based on the rule should not

significantly increase the probability or

consequences of accidents; no changes

will be made in the types of any

effluents that may be released off site;

and there should be no significant

increase in occupational or public

radiation exposure. Therefore, there are

no significant radiological

environmental impacts associated with

the action. The action does not involve

non-radiological plant effluents and has

no other environmental impact.

Therefore, there are no significant nonradiological environmental impacts

associated with the final rule.

The determination of the

environmental assessment is that there

will be no significant offsite impact on

the public from this action. Also, the

NRC has committed itself to complying

in all its actions with Executive Order

(E.O.) 12898, ‘‘Federal Actions To

Address Environmental Justice in

Minority Populations and Low-Income

Populations,’’ dated February 11, 1994.

The NRC has determined that there are

no disproportionately high and adverse

impacts on minority and low-income

populations. The NRC uses the

following working definition of

environmental justice: Environmental

justice means the fair treatment and

meaningful involvement of all people,

regardless of race, ethnicity, culture,

income, or educational level with

respect to the development,

implementation and enforcement of

environmental laws, regulations, and

policies. In the letter and spirit of E.O.

12898, the NRC requested public

comments on environmental justice

considerations or other questions

related to this rule, but none were

received.

Paperwork Reduction Act Statement

This final rule increases the burden

on licensees opting to use a reduced

power level assumption for ECCS

analysis (i.e., below 102 percent) to

include the change in their annual

report required under 10 CFR 50.46

(a)(3)(ii). The public burden to modify

the annual report is estimated to average

one-half hour per response. The

estimated public burden for record

keeping, analysis, and other effort

associated with this information

collection will be included in the Office

of Management and Budget FY2000

Information Collection Budget. Existing

requirements were approved by the

Office of Management and Budget,

approval number 3150–0011.

Public Protection Notification

If a means used to impose an

information collection does not display

a currently valid OMB control number,

the NRC may not conduct or sponsor,

and a person is not required to respond

to, the information collection.

Regulatory Analysis

The Commission has prepared a

regulatory analysis on this regulation.

Copies of the regulatory analysis may be

obtained as indicated in the ADDRESSES

section.

Federal Register / Vol. 65, No. 106 / Thursday, June 1, 2000 / Rules and Regulations 34921

Regulatory Flexibility Certification

As required by the Regulatory

Flexibility Act of 1980, 5 U.S.C. 605(b),

the Commission certifies that this final

rule does not have a significant

economic impact on a substantial

number of small entities. This final rule

would affect only the licensing and

operation of nuclear power plants. The

companies that own these plants do not

fall within the definition of ‘‘small

entities’’ found in the Regulatory

Flexibility Act or within the size

standards established by the NRC in 10

CFR 2.810.

Backfit Analysis

The NRC has determined that the

backfit rule in 10 CFR 50.109 does not

apply to this final rule and that a backfit

analysis is not required for this

amendment because the change does

not involve any provisions that impose

backfits as defined in 10 CFR

50.109(a)(1). The final rule establishes

an alternative approach for ECCS

performance evaluations that may be

voluntarily adopted by licensees.

Licensees may continue to comply with

existing requirements in Appendix K.

The final rule does not impose a new

requirement on current licensees and

therefore, does not constitute a backfit

as defined in 10 CFR 50.109(a)(1).

Small Business Regulatory Enforcement

Fairness Act

In accordance with the Small

Business Regulatory Enforcement

Fairness Act of 1996, the NRC has

determined that this action is a major

rule and has verified this determination

with the Office of Information and

Regulatory Affairs of‘OMB.

List of Subjects in 10 CFR Part 50

Antitrust, Classified information,

Criminal penalties, Fire protection,

Intergovernmental relations, Nuclear

power plants and reactors, Radiation

protection, Reactor siting criteria,

Reporting and recordkeeping

requirements.

For the reasons set out in the

preamble and under the authority of the

Atomic Energy Act of 1954, as amended;

the Energy Reorganization Act of 1974,

as amended; and 5 U.S.C. 552 and 553,

the NRC is adopting the following

amendments to 10 CFR part 50.

PART 50—DOMESTIC LICENSING OF

PRODUCTION AND UTILIZATION

FACILITIES

1. The authority citation for part 50

continues to read as follows:

Authority: Sections 102, 103, 104, 105,

161, 182, 183, 186, 189, 68 Stat. 936, 937,

938, 948, 953, 954, 955, 956, as amended,

sec. 234, 83 Stat. 444, as amended (42 U.S.C.

2132, 2133, 2134, 2135, 2201, 2232, 2233,

2236, 2239, 2282); secs. 201, as amended,

202, 206, 88 Stat. 1242, as amended, 1244,

1246 (42 U.S.C. 5841, 5842, 5846).

Section 50.7 also issued under Pub. L. 95–

601, sec. 10, 92 Stat. 2951 (42 U.S.C. 5851).

Section 50.10 also issued under secs. 101,

185, 68 Stat. 955, as amended (42 U.S.C.

2131, 2235), sec. 102, Pub. L. 91–190, 83 Stat.

853 (42 U.S.C. 4332). Sections 50.13,

50.54(dd), and 50.103 also issued under sec.

108, 68 Stat. 939, as amended (42 U.S.C.

2138). Sections 50.23, 50.35, 50.55, and 50.56

also issued under sec. 185, 68 Stat. 955 (42

U.S.C. 2235). Sections 50.33a, 50.55a, and

Appendix Q also issued under sec. 102, Pub.

L. 91–190, 83 Stat. 853 (42 U.S.C. 4332).

Sections 50.34 and 50.54 also issued under

sec. 204, 88 Stat. 1245 (42 U.S.C. 5844).

Sections 50.58, 50.91, and 50.92 also issued

under Pub. L. 97–415, 96 Stat. 2073 (42

U.S.C. 2239). Section 50.78 also issued under

sec. 122, 68 Stat. 939 (42 U.S.C. 2152).

Sections 50.80–50.81 also issued under sec.

184, 68 Stat. 954, as amended (42 U.S.C.

2234). Appendix F also issued under sec.

187, 68 Stat. 955 (42 U.S.C. 2237).

2. Appendix K to part 50 is amended

by revising the introductory paragraph

of I. A., ‘‘Sources of heat during the

LOCA,’’ to read as follows:

Appendix K to Part 50—ECCS

Evaluation Models

I. Required and Acceptable Features of the

Evaluation Models

A. Sources of heat during the LOCA. For

the heat sources listed in paragraphs I.A.1 to

4 of this appendix it must be assumed that

the reactor has been operating continuously

at a power level at least 1.02 times the

licensed power level (to allow for

instrumentation error), with the maximum

peaking factor allowed by the technical

specifications. An assumed power level

lower than the level specified in this

paragraph (but not less than the licensed

power level) may be used provided the

proposed alternative value has been

demonstrated to account for uncertainties

due to power level instrumentation error. A

range of power distribution shapes and

peaking factors representing power

distributions that may occur over the core

lifetime must be studied. The selected

combination of power distribution shape and

peaking factor should be the one that results

in the most severe calculated consequences

for the spectrum of postulated breaks and

single failures that are analyzed.

* * * * *

Dated at Rockville, Maryland, this 26th day

of May 2000.

For the Nuclear Regulatory Commission.

J. Samuel Walker,

Acting Secretary of the Commission.

[FR Doc. 00–13745 Filed 5–31–00; 8:45 am]

BILLING CODE 7590–01–P

NATIONAL CREDIT UNION

ADMINISTRATION

12 CFR Part 745

Share Insurance and Appendix

AGENCY: National Credit Union

Administration (NCUA).

ACTION: Final rule.

SUMMARY: The NCUA is issuing a final

rule amending its share insurance rules.

The amendments simplify and clarify

these rules and provide parity between

them and the Federal Deposit Insurance

Corporation’s (FDIC) deposit insurance

rules. Specifically, the amendments:

increase available share insurance

coverage on some revocable trust

accounts; simplify the method for

determining the insurance coverage a

member has in one or more joint

accounts; treat a revocable trust account

held in connection with a living trust as

any other revocable trust accounts, if the

living trust meets all requirements

pertaining to revocable trusts; provide

separate insurance coverage for

qualifying joint revocable trust

accounts; treat Roth IRAs as traditional

IRAs and Education IRAs as irrevocable

trusts for insurance purposes; liberalize

insurance coverage for some kinds of

public unit accounts; clarify the degree

of control state or local law has on share

insurance determinations and revise the

substance and format of the Appendix

to part 745.

DATES: This rule is effective July 3,

2000.

ADDRESSES: National Credit Union

Administration, 1775 Duke Street,

Alexandria, VA 22314–3428.

FOR FURTHER INFORMATION CONTACT:

Frank S. Kressman, Staff Attorney,

Division of Operations, Office of

General Counsel, at the above address,

or telephone: (703) 518–6540.

SUPPLEMENTARY INFORMATION:

A. Background

In accordance with NCUA’s

regulatory review process, at year end

1998, NCUA staff identified part 745 as

one of its regulations in need of

updating, clarification and

simplification. On April 15, 1999, the

NCUA Board issued an interim final

rule adopting changes to its share

insurance rules regarding joint accounts

and revocable trust accounts. 64 FR

19685 (April 22, 1999). The FDIC

adopted similar changes to its deposit

insurance rules on March 23, 1999. 64

FR 15653 (April 1, 1999). When issuing

the interim rule, NCUA was aware that

additional changes to part 745 were

necessary and would be forthcoming,