Federal Register / Vol. 69, No. 212 / Wednesday, November 3, 2004 / Notices 64115

7Westinghouse Electric Company Topical Report, 

Addendum 1 to WCAP–12610–P–A and CENPD–

404–P–A, ‘‘Optimized ZIRLO’’, February 2003.

promote consequences beyond those 

currently analyzed. 

3.2 ECCS Performance and 

Exemptions 

Pursuant to 10 CFR 50.12, the 

Commission may, upon application by 

any interested person or own initiative, 

grant exemptions from the requirements 

of 10 CFR part 50 when (1) 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) special circumstances are present. 

Special circumstances are present if 

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 

50.46 is to establish acceptance criteria 

for ECCS performance. In Addendum 1 

to WCAP–12610–P–A (Reference 7)7, 

Westinghouse demonstrates that the 

material properties of Optimized 

ZIRLOTM are similar to those of the 

currently approved ZIRLOTM cladding 

and that the ECCS acceptance criteria 

for ZIRLOTM clad fuel are also 

applicable to fuel with Optimized 

ZIRLOTM cladding. Ring compression 

tests performed by Westinghouse on 

Optimized ZIRLOTM demonstrate an 

acceptable retention of ductility up to 

10 CFR 50.46 limits of 2200 °F peak 

cladding temperature and 17 percent 

total oxidation. Utilizing currently 

approved LOCA models and methods, 

Westinghouse will perform cyclespecific reload evaluations to ensure 

that the Optimized ZIRLOTM LTAs 

satisfy 10 CFR 50.46 acceptance criteria.

Paragraph I.A.5 of Appendix K to 10 

CFR part 50 states that the rates of 

energy, hydrogen concentration, and 

cladding oxidation from the metal-water 

reaction shall be calculated using the 

Baker-Just equation. Since the BakerJust equation presumes the use of 

zircaloy clad fuel, strict application of 

the rule would not permit use of the 

equation for the Optimized ZIRLOTM

LTA cladding for determining 

acceptable fuel performance. Metalwater reaction tests performed by 

Westinghouse on Optimized ZIRLOTM

(documented in Appendix B of 

Addendum 1 to WCAP–12610–P–A) 

demonstrate conservative reaction rates 

relative to the Baker-Just equation. 

Thus, application of Appendix K, 

Paragraph I.A.5, in these circumstances, 

is not necessary for the licensee to 

achieve the underlying purpose of the 

regulation. 

Based upon the results of metal-water 

reaction tests and ring-compression 

tests, which ensure the applicability of 

ECCS models and acceptance criteria 

and the use of approved LOCA models 

to ensure that the Optimized ZIRLOTM

LTAs satisfy 10 CFR 50.46 acceptance 

criteria, the NRC staff finds it acceptable 

to grant an exemption from the 

requirements of 10 CFR 50.46 and 

Appendix K to 10 CFR part 50 for the 

use of up to eight LTAs in STP, Units 

1 and 2. 

3.3 Special Circumstances 

In summary, the NRC staff has 

reviewed the licensee’s request for an 

exemption to allow up to eight LTAs 

containing fuel rods, guide thimble 

tubes, and instrumentation tubes 

fabricated with Optimized ZIRLOTM to 

be used in STP, Units 1 and 2. Based on 

the NRC staff’s evaluation, as set forth 

above, the NRC staff considers that 

granting the proposed exemption will 

not defeat the underlying purpose of 10 

CFR 50.46, or Appendix K to 10 CFR 

part 50. Accordingly, special 

circumstances, are present pursuant to 

10 CFR 50.12(a)(2)(ii). 

3.4 Other Standards in 10 CFR 50.12 

The NRC staff reviewed information 

provided by the licensee in References 

1 and 2 to support the exemption 

request, and concluded that the use of 

Optimized ZIRLOTM would satisfy 10 

CFR 50.12(a) as follows: 

(1) The requested exemption is 

authorized by law: 

No law precludes the activities 

covered by this exemption request. The 

Commission, based on technical reasons 

set forth in rulemaking records, 

specified the specific cladding materials 

identified in 10 CFR 50.46 and 10 CFR 

part 50, Appendix K. Cladding materials 

are not specified by statute. 

(2) The requested exemption does not 

present an undue risk to the public 

health and safety. As stated by the 

licensee in Reference 1:

The lead test assembly safety evaluation 

will ensure that these acceptance criteria are 

met following insertion of the assemblies 

containing Optimized ZIRLOTM material. 

Fuel assemblies using Optimized ZIRLOTM

cladding will be evaluated using NRCapproved analytical methods and will 

address the changes in the cladding material 

properties. The safety analysis for the South 

Texas Project is supported by the applicable 

technical specifications. The South Texas 

Project reload cores containing Optimized 

ZIRLOTM cladding will continue to be 

operated in accordance with the operating 

limits specified in the technical 

specifications. Lead test assemblies using 

Optimized ZIRLOTM cladding will be placed 

in non-limiting core locations. Therefore, this 

exemption will not pose an undue risk to 

public health and safety.

The NRC staff has evaluated these 

considerations as set forth in Section 3.1 

and 3.2 of this Exemption. For the 

reasons set forth in Sections 3.1 and 3.2, 

the NRC staff concludes that Optimized 

ZIRLOTM may be used as a cladding 

material for up to eight LTAs to be 

placed in non-limiting core locations in 

STP, Units 1 and 2, and that an 

exemption from the requirements of 10 

CFR 50.46 and 10 CFR part 50, 

Appendix K, does not pose an undue 

risk to the public health and safety. 

(3) The common defense and security 

are not affected and, therefore, not 

endangered by this exemption. 

4.0 Conclusion 

Accordingly, the Commission has 

determined that, pursuant to 10 CFR 

50.12(a), the exemption is authorized by 

law, will not present an undue risk to 

the public health and safety, and is 

consistent with the common defense 

and security. Also, special 

circumstances are present. Therefore, 

the Commission hereby grants STPNOC 

an exemption from the requirements of 

10 CFR part 50, Appendix K and 

Section 50.46, for the use of up to eight 

LTAs containing Optimized ZIRLOTM in 

STP, Units 1 and 2, up to a lead rod 

average burnup of 62,000 megawatt days 

per metric ton of uranium. 

Pursuant to 10 CFR 51.32, the 

Commission has determined that the 

granting of this exemption will not have 

a significant effect on the quality of the 

human environment (69 FR 45352). 

This exemption is effective upon 

issuance.

For the Nuclear Regulatory Commission. 

Ledyard B. Marsh, 

Director, Division of Licensing Project 

Management, Office of Nuclear Reactor 

Regulation.

[FR Doc. 04–24493 Filed 11–2–04; 8:45 am] 

BILLING CODE 7590–01–P

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COMMISSION 

Draft Appendix C (DG–1138) to 

Regulatory Guide 1.200, ‘‘An Approach 

for Determining the Technical 

Adequacy of Probabilistic Risk 

Assessment Results for Risk-Informed 

Activities,’’ Workshop 

The U.S. Nuclear Regulatory 

Commission (NRC) has issued draft 

Appendix C, ‘‘NRC Staff Position on 

ANS External Hazards PRA Standard’’

in August 2004. This Appendix will be 

64116 Federal Register / Vol. 69, No. 212 / Wednesday, November 3, 2004 / Notices 

part of Regulatory Guide 1.200, ‘‘An 

Approach for Determining the Technical 

Adequacy of Probabilistic Risk 

Assessment Results for Risk-Informed 

Activities’’ which was issued for trial 

use. The Appendix C was issued for 

public comment on August 31, 2004, 

and is available under ADAMS 

Accession Number ML042430314. 

Revision 1 to RG 1.200, which will 

include a final draft Appendix C, will be 

issued next year for public comment. 

Regulatory Guides (RGs) are developed 

to describe and make available to the 

public such information as methods 

acceptable to the NRC staff for 

implementing specific parts of the 

NRC’s regulations, techniques used by 

the staff in evaluating specific problems 

or postulated accidents, and data 

needed by the staff in its review of 

applications for permits and licenses. 

This draft Appendix C is being 

developed to provide the staff’s 

preliminary position on the American 

Nuclear Society, (ANS) Standard, 

External-Events Probabilistic Risk 

Assessment (PRA) Methodology. This 

draft Appendix C has not received 

complete staff approval and does not 

represent an official NRC staff position. 

It is the NRC’s intent to update 

Appendix C when a revised ANS 

standard on external events is 

published. Therefore, if a revision of the 

current ANS standard impacts the staff 

position, this Appendix C will be 

revised. 

The NRC will conduct a workshop on 

November 9, 2004, to be held in room 

O4B6 at NRC headquarters, 11545 

Rockville Pike, Rockville, Maryland. 

The purpose of the workshop is to 

facilitate the comment process. In the 

workshop, the staff will discuss the 

staff’s response to the public comments 

received and the basis for the staff’s 

position, and answer questions. A 

preliminary agenda is attached. The 

staff is also requesting comments on the 

following general issues and two 

specific issues. The general issues are: 

• The intent was that the ANS 

standard be seamless with the American 

Society of Mechanical Engineers 

(ASME) PRA standard for internal 

events. However, this has not been 

achieved for the following reasons: 

In the ASME Standard, the word 

‘‘shall’’ is only used in high level 

requirements, and permissive words 

such as ‘‘should’’ or ‘‘may’’ are not used 

in any requirements. The ANS Standard 

on external-events uses permissive 

words in both high level and supporting 

requirements. Permissive words are not 

to be used because they cannot be used 

to define a minimum requirement. 

The ANS Standard interprets the use 

of supporting requirements that cut 

across capability categories in a 

different manner from the ASME 

Standard (see discussion in Section 1.4 

of the ANS Standard). In the ASME 

Standard, a requirement that is the same 

for more than one capability category, is 

to be interpreted as a pass/no-pass 

requirement with no requirement to 

allocate a capability category.

♦ The organization of the ANS 

Standard is different from that of the 

ASME Standard. In the ASME Standard 

the applications chapter is Chapter 3, 

whereas in the ANS Standard it is 

Chapter 6. 

♦ Some definitions are not consistent 

with those in the ASME Standard. 

• The staff considers the use of 

explanatory notes is helpful in 

principle. However, several of the notes 

contain what the staff interprets as 

requirements (see example, SR WIND–

A1). 

• The staff has identified several 

missing supporting requirements. These 

include, for each of the hazards, 

requirements to identify the Structures 

Systems and Components (SSCs) that 

are critical to plant safety, SSCs that are 

vulnerable to the hazard being 

evaluated, identification of specific 

failure modes, and identification of the 

modification of PRA logic to model 

these failures. 

In addition to these general issues, 

there are two specific issues on which 

the staff requests comment. 

• Section 3.4 of the ANS Standard 

addresses screening of external hazards. 

In Section 3.4.2, three fundamental (sic) 

quantitative screening criteria are 

introduced, that focus on core damage 

frequency (CDF). The last paragraph 

recognizes that large early release 

frequency (LERF) should also be 

considered in the screening but does not 

suggest additional requirements. One 

approach is to lower the numerical 

criteria (e.g., in REQ.EXT–C1) to result 

in screening at a CDF of 1E–07 rather 

than 1E–06. Is this an acceptable 

approach, or are there alternative 

approaches based on a more qualitative 

approach dealing with the releases? 

• Appendix D in the ANS Standard is 

a nonmandatory appendix that provides 

guidance on uses of a seismic margins 

assessment with enhancements. The 

seismic margin approach, while can be 

used for certain applications, is not a 

PRA. Since this standard is providing 

requirements for an external events 

PRA, the staff takes objection to this 

appendix. The staff believes the 

appropriate place to provide its position 

on this appendix would be in the 

NUREG being prepared by the Office of 

Nuclear Regulatory Research addressing 

the use of non-PRA methods in riskinformed decision-making. Is this an 

appropriate strategy? 

For information about the draft 

Appendix C and the workshop, contact 

Mr. A. Singh at (301) 415–0250; e-mail 

axs3@NRC.GOV.

Although a time limit is given for 

comments on this draft Appendix C, 

comments and suggestions in 

connection with items for inclusion in 

guides, currently being developed, or 

improvements in all published guides, 

are encouraged at any time.

Authority: (5 U.S.C. 552(a)).

Dated at Rockville, Maryland, this 26th day 

of October 2004.

For the Nuclear Regulatory Commission. 

Charles E. Ader, 

Director, Division of Risk Analysis and 

Applications, Office of Nuclear Regulatory 

Research.

Public Workshop on Draft Appendix C 

‘‘NRC Staff Regulatory Position on ANS 

External Hazards PRA Standard’’ to 

Regulatory Guide 1.200 for Trial Use 

‘‘An Approach for Determining the 

Technical Adequacy of Probabalistic 

Risk Assessment Results for Risk 

Informed Activities’’

November 9, 2004—10 a.m.–3 p.m. 

Room O–4B6 

Preliminary Agenda 

10 a.m.–10:15 a.m. 

Introduction—NRC 

10:15 a.m.–10:30 a.m. 

Overview of Appendix C—NRC 

10:30 a.m.–11 a.m. 

Overall, general staff’s response to 

public comments 

11 a.m.–12 Noon 

Detailed discussion on specific 

Comments 

12 Noon–1 p.m. 

LUNCH 

1 p.m.–2 p.m. 

Detailed discussion (cont’d) 

2 p.m.–2:45 p.m. 

Open Discussion 

2:45 p.m.–3 p.m. 

Wrap-up 

3 p.m. 

ADJOURN

[FR Doc. 04–24494 Filed 11–2–04; 8:45 am] 

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COMMISSION 

Proposed Collection; Comment 

Request 

Upon written request, copies available 

from: Securities and Exchange