RULEMAKING ISSUE

INFORMATION

December 22, 2003 SECY-03-0219

FOR: The Commissioners

FROM: William D. Travers 

Executive Director for Operations

SUBJECT: TERMINATION OF RULEMAKING TO ADD M5TM CLADDING TO

10 CFR 50.46, “ACCEPTANCE CRITERIA FOR EMERGENCY CORE

COOLING SYSTEMS FOR LIGHT-WATER NUCLEAR POWER REACTORS”

(WITS 200300060)

PURPOSE:

To inform the Commission of the staff’s decision to terminate rulemaking to add M5TM fuel

cladding to the cladding materials listed in 10 CFR 50.46, “Acceptance Criteria for Emergency

Core Cooling Systems for Light-Water Nuclear Power Reactors.” The staff had planned to add

M5TM by way of a final rule to resolve, in part, the Nuclear Energy Institute’s (NEI’s) Petition for

Rulemaking (PRM) 50-71, “Use of Cladding Material Other Than Zircaloy or ZIRLOTM,” which

requested that the Nuclear Regulatory Commission (NRC) allow licensees to use zirconiumbased cladding materials other than zircaloy or ZIRLOTM. However, the staff is now planning to

develop a performance-based rule that will grant PRM 50-71 in its entirety, by replacing the list

of trademarked cladding materials in 10 CFR 50.46 with the words “zirconium-based cladding

materials,” as soon as the necessary technical basis can be developed to support the change. 

Development of the technical basis will include identification of the critical characteristics of the

fuel cladding under both normal operating conditions and accident conditions, as well as the

testing criteria needed to confirm adequate cladding material performance under those

conditions.

CONTACT: Merrilee Banic, NRR/DRIP

(301) 415-2771
1

A final rule(68 FR 54123) deletes the references to zircaloy and ZIRLOTM fuel cladding

from 10 CFR 50.44 as part of the risk-informed rulemaking to revise 10 CFR 50.44.

The Commissioners 2

DISCUSSION:

On May 31, 2000 (65 FR 34599), the NRC published a notice in the Federal Register

requesting comment on a petition for rulemaking submitted by NEI. The petitioner requested

that the NRC amend its regulations in 10 CFR 50.44, “Standards for combustible gas control

system in light-water-cooled power reactors,” and 50.46, “Acceptance criteria for emergency

core cooling systems for light-water nuclear power reactors,” to allow nuclear power plant

licensees to use zirconium-based cladding materials other than zircaloy or ZIRLOTM. The

petitioner noted that after these regulations were issued, commercial nuclear fuel vendors

developed, and continue to develop, materials other than zircaloy or ZIRLOTM that NRC reviews

and approves for use with commercial power reactor fuel. Each of these approvals requires the

NRC to grant an exemption to the licensee that requests use of fuel in cladding materials other

than zircaloy or ZIRLOTM. The petitioner requested that NRC amend §§ 50.44 and 50.46 to

provide licensees the discretion to use zirconium-based cladding materials other than zircaloy

or ZIRLOTM, provided that the cladding materials meet staff “accepted fuel cladding

performance requirements.” The petitioner asserted that the proposed amendment would not

degrade the ability to meet regulatory criteria. Rather, it would remove an unwarranted

licensing burden without increasing risk to public health and safety.

After the staff recommended proceeding with the proposed M5TM rulemaking, the Commission

approved the staff’s efforts to develop a performance-based rule for 10 CFR 50.46. In a Staff

Requirements Memorandum dated March 31, 2003, on SECY-02-0057, the Commission

approved the staff’s recommendation to proceed with modifications to 10 CFR 50.46 to provide

for a more performance-based approach to meeting ECCS acceptance criteria. The

performance-based approach includes developing acceptance criteria for cladding performance

such that licensees would be able to use materials other than zircaloy or ZIRLOTM without an

exemption.1

 The research necessary to support the performance-based rulemaking is currently

underway. 

Once the information from research becomes available, the staff will proceed with developing

the proposed performance-based rule. The proposed performance-based rule would achieve

the full purpose of the NEI petition, whereas a more limited rulemaking adding one specific alloy 

would be a temporary step, since additional cladding materials are being developed. Given that

fuel vendors are continuing to introduce new cladding materials with improved performance 

characteristics, the staff believes that adding new trademarked cladding materials to the list in

10 CFR 50.46 each time a new material is developed is not an efficient use of agency

resources. Therefore, the staff plans to proceed with resolution of the NEI petition through the

performance-based rulemaking, and to terminate the more limited rulemaking effort to explicitly

add M5TM to 10 CFR 50.46.
The Commissioners 3

RESOURCES:

Resources are available within the current budget to continue the activity to develop the

technical basis for a performance-based rule. Resources for a performance-based rule will be

included in the Fiscal Year (FY)06 budget. 

SCHEDULE:

The Office of Nuclear Regulatory Research is currently conducting confirmatory research on

irradiated zircaloy cladding and unirradiated M5 cladding, which should be completed in late

FY04. The results of this research will help the staff develop the technical basis to support

performance-based criteria for fuel cladding material in FY05. The staff plans to include the

performance-based rulemaking effort in the FY06 budget. If the performance-based criteria is

developed ahead of schedule, the staff will consider beginning the rulemaking effort in FY05, if

resources are available.

COORDINATION:

The Office of the General Counsel has no legal objection to this paper.

/RA/

William D. Travers

Executive Director 

 for Operations
The Commissioners 3

RESOURCES:

Resources are available within the current budget to continue the activity to develop the

technical basis for a performance-based rule. Resources for a performance-based rule will be

included in the Fiscal Year (FY)06 budget. 

SCHEDULE:

The Office of Nuclear Regulatory Research is currently conducting confirmatory research on

irradiated zircaloy cladding and unirradiated M5 cladding, which should be completed in late

FY04. The results of this research will help the staff develop the technical basis to support

performance-based criteria for fuel cladding material in FY05. The staff plans to include the

performance-based rulemaking effort in the FY06 budget. If the performance-based criteria is

developed ahead of schedule, the staff will consider beginning the rulemaking effort in FY05, if

resources are available.

COORDINATION:

The Office of the General Counsel has no legal objection to this paper.

/RA/

William D. Travers

Executive Director 

 for Operations

ADAMS ACCESSION NO.: ML033381047

WITS 200300060

OFFICE RPRP Tech Ed RPRP RPRP:PD D:DSSA D:DRIP

NAME MBanic* PKleene* DSkeen* CHaney* SBlack* DMatthews*

DATE 10/15/03 10/15/03 12/3/03 12/3/03 12/3/03 12/3/03 

OFFICE ADM OGC D:RES ADIP D:NRR EDO

NAME MLesar STreby* AThadani JCraig JDyer WTravers

DATE 12/4/03 12/4/03 12/4/03 12/10/03 12/12/03 12/22/03 

OFFICIAL RECORD COPY