[Federal Register Volume 66, Number 197 (Thursday, October 11, 2001)]
[Proposed Rules]
[Pages 51884-51886]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-25565]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 66, No. 197 / Thursday, October 11, 2001 /
Proposed Rules
[[Page 51884]]
NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[Docket No. PRM-50-74]
Nuclear Energy Institute; Receipt of Petition for Rulemaking
AGENCY: Nuclear Regulatory Commission.
ACTION: Petition for rulemaking; notice of receipt.
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SUMMARY: The Nuclear Regulatory Commission (NRC) is publishing for
public comment a notice of receipt of a petition for rulemaking, dated
September 6, 2001, which was filed with the Commission by the Nuclear
Energy Institute (NEI). The petition was docketed by the NRC on
September 11, 2001, and has been assigned Docket No. PRM-50-74. The
petition requests that the NRC amend its regulations regarding
Emergency Core Cooling System (ECCS) Evaluation Models to allow
licensees to voluntarily adopt the most current industry consensus
standard for decay heat power, as well as any subsequent NRC-endorsed
revisions to this standard.
DATES: Submit comments by December 26, 2001. Comments received after
this date will be considered if it is practical to do so, but assurance
of consideration can only be given to comments received on or before
this date.
ADDRESSES: Mail comments to: Secretary, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, Attention: Rulemakings and
Adjudications Staff.
Deliver comments to: 11555 Rockville Pike, Rockville, Maryland
between 7:30 a.m. and 4:15 p.m. on Federal workdays.
For a copy of the petition, write to Michael T. Lesar, Chief, Rules
and Directives Branch, Division of Administrative Services, Office of
Administration, U. S. Nuclear Regulatory Commission, Washington, DC
20555-0001.
You may also provide comments via the NRC's interactive rulemaking
Web site at http://ruleforum.llnl.gov. This site allows you to upload
comments as files in any format, if your web browser supports the
function. The petition and any public comments received are available
on the site. For information about the interactive rulemaking Web site,
contact Carol Gallagher at (301) 415-5905 or via e-mail at [email protected].
The petition and copies of comments received may be inspected, and
copied for a fee, at the NRC Public Document Room, (first floor) 11555
Rockville Pike, Rockville, Maryland.
The NRC maintains an Agencywide Documents Access and Management
System (ADAMS), which provides text and image files of NRC's public
documents. These documents may be accessed through the NRC's Public
Electronic Reading Room (PERR) on the Internet at http://www.nrc.gov/NRC/ADAMS/index.html. If you do not have access to ADAMS or if there
are problems in accessing the documents located in ADAMS, contact the
NRC Public Document Room (PDR) Reference staff at 1-800-397-4209, 301-
415-4737 or by e-mail to [email protected].
FOR FURTHER INFORMATION CONTACT: Michael T. Lesar, Office of
Administration, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001. Telephone: 301-415-7163 or Toll-free: 1-800-368-5642. E-
mail: [email protected].
SUPPLEMENTARY INFORMATION:
Background
The Nuclear Regulatory Commission received a petition for
rulemaking dated September 6, 2001, submitted by the Nuclear Energy
Institute (the petitioner). The petition was docketed by the NRC on
September 11, 2001, and has been assigned Docket No. PRM-50-74.
The Petitioner
The Nuclear Energy Institute (NEI), petitioning on behalf of the
nuclear energy industry, requests that the NRC amend its regulations
relating to the standards to be used for the estimation of decay heat
power in licensees' emergency core cooling evaluation models.
The Petitioner's Request
The petitioner requests that the NRC amend Appendix K to 10 CFR
part 50, ECCS Evaluation Models, to allow licensees to voluntarily
adopt the latest industry consensus standard on decay heat rates, ANS/
ANSI-5.1-1994, a standard developed by the American Nuclear Society
(ANS) and approved by the American National Standards Institute (ANSI).
The petitioner also asks that licensees be given the option to adopt,
without further rulemaking, any subsequent revisions to this standard
that the NRC endorses.
History of the Issue Addressed in the Petition
The Standard Cited in the Current Regulation
In Appendix K to 10 CFR part 50, Section I.A.4., Fission Product
Decay, currently reads:
The heat generation rates from radioactive decay of fission
products shall be assumed to be equal to 1.2 times the values for
infinite operating time in the ANS Standard (Proposed American
Nuclear Society Standards--``Decay Energy Release Rates Following
Shutdown of Uranium-Fueled Thermal Reactors.'' Approved by
Subcommittee ANS-5, ANS Standards Committee, October 1971).
The petitioner notes that this proposed ANS standard for decay heat
was submitted to ANSI by ANS in 1971, but claims that ANSI, after
approving minor revisions to the standard, tabled action on the
standard in October 1973. The petitioner maintains that, because ANSI
took no subsequent action on the proposed 1971 ANS standard, it retains
the status of a proposed rather than an adopted industry consensus
standard to this day.
The petitioner states that the proposed 1971 ANS standard was based
on the curve recommended by K. Shure for infinite irradiation of
uranium and for cooling times from 0 to 10 9 seconds.
According to the petitioner, this approach was simplistic in that it
employed a single curve to represent the decay heat power of all
uranium-fueled thermal reactors. The petitioner believes that this
approach ignores the fact that many phenomena make decay heat power
unique to each fuel isotope. These phenomena, explains the petitioner,
were assumed to be included within the appropriately large
uncertainties that were adopted by the ANS-5.1 Working Group on the
basis of the comparison of data available at the time.
[[Page 51885]]
Subsequent ANS Decay Heat Standards
The petitioner states that, in October 1978, the ANS Nuclear Power
Plant Standards Committee (NUPPSCO) approved a standard entitled
``Decay Heat Power in Light Water Reactors.'' According to the
petitioner, this standard was developed to fulfill a need for
evaluations of fission reactor performance based upon improved
knowledge of decay heat power in the fuel elements. The petitioner
notes that, although this new standard replaced the standard proposed
in 1971, the NRC has not endorsed the updated standard in appendix K to
10 CFR Part 50.
According to the petitioner, NUPPSCO approved a standard in August
1994 entitled ``Decay Heat Power in Light Water Reactors,'' which
incorporated new measurements of decay heat that had been published
after adoption of the 1978 standard. The petitioner states that the
1994 standard also drew upon improved nuclear databases, which resulted
in more precise summation calculations of decay heat. According to the
petitioner, comparisons of elements of the 1978 standard with results
of the new measurements and the new summation calculations had been
published in a 1991 report, which proposed improvements to the existing
(1978) standard. In response to this report, tabular data in tables
entitled ``Data for Standard Decay Heat Power'' and associated
uncertainties were re-evaluated for three fuel isotopes--U
235, U 238, and Pu 239--and newly
evaluated for Pu 241. The petitioner notes that the 1994
revision to ANS-5.1, which included the results of these new
evaluations, has not been endorsed by the NRC in Appendix K to 10 CFR
50.
The Petitioner's Proposed Amendment
The petitioner proposes that Appendix K to 10 CFR Part 50 be
amended to give licensees the option to adopt the 1994 standard (ANS/
ANSI-5.1-1994), and to allow licensees to adopt any subsequent
revisions to the standard endorsed by the NRC. The petitioner's
proposed amendment to Appendix K.I.A.4. reads (verbatim) as follows:
4. Fission Product Decay. The heat generation rates from
radioactive decay of fission products shall be either (a) assumed to
be equal to 1.2 times the values for infinite operation time
published in the 1971 ANS Standard (Proposed American Nuclear
Society Standards--``Decay Energy Release Rates Following Shutdown
of Uranium-Fueled Thermal Reactors.'' Approved by Subcommittee ANS-
5, ANS Standards Committee, October 1971). This standard has been
approved for incorporation by reference by the Director of the
Federal Register. A copy of the standard is available for inspection
at the NRC Library, 11545 Rockville Pike, Rockville, Maryland 20852-
2738. The fraction of the locally generated gamma energy that is
deposited in the fuel (including the cladding) may be different from
1.0; the value used shall be justified by a suitable calculation; or
(b) taken from the 1994 ANS Standard (American Nuclear Society
Standards--``Decay Heat Power in Light Water Reactors.'' Approved by
ANS Nuclear Power Plant Standards Committee ANS-5.1 and American
National Standards Institute, Inc., August 1994); or (c) taken from
any subsequent revisions to the ANS Decay Heat standard that are
endorsed by the NRC.
The Petitioner's Justification for the Amendment
Because the petitioner's proposed amendment of appendix K to 10 CFR
part 50 makes adoption of the 1994 standard, or any subsequent revision
to it, optional for licensees, the petitioner declines to provide a
cost-benefit analysis for its proposal. However, the petitioner sets
out the following four arguments in support of the proposed amendment.
The 1994 Standard Incorporates More Precise Results, Is More Explicit,
and Uses a Statistical Approach To Address Uncertainty
According to the petitioner, the uncertainty bands for the proposed
1971 standard currently endorsed by the NRC were chosen on the basis of
data published between 1950 and 1963. The current regulation specifies
that fission product decay rates be calculated by multiplying the
values for infinite operating time in the proposed 1971 ANS Standard by
a factor of 1.2. The petitioner states that the ANS Standards
Subcommittee 5 has concluded that this factor appears to have been
based upon the ANS uncertainty for cooling time (i.e., time after
shutdown) less than or equal to 10 3 seconds.
The petitioner notes that, in contrast, the 1994 ANS standard
expresses uncertainty statistically as one standard deviation in a
normal distribution. The petitioner notes that the 1994 standard
explicitly addresses and incorporates a conservative multiplying factor
of 1.02 for the increase over U\235\ decay heat power from U\238\
fission products at typical U\238\ fission rates. The petitioner notes
that this multiplication factor was determined in 1974 by the ANS-5.1
Working Group, which was comprised of researchers, industry
representatives, and knowledgeable NRC personnel. According to the
petitioner, the basis for the advanced statistical approach used in the
1994 standard was derived from numerous contemporary data measurements,
providing essentially equivalent results. The petitioner states that
the revised 1994 standard for LOCA (loss of coolant accident)
applications includes cooling time up to 10\4\ seconds and incorporates
more precise results than the proposed 1971 standard currently endorsed
by the NRC, including detailed evaluation of the influence of neutron
capture in fission products for the shutdown range, and cooling times
up to 10\9\ seconds.
Federal Law Requires NRC To Utilize Technical Standards Developed by
Voluntary Consensus Standard Bodies
The petitioner states that, pursuant to Management Directive 6.5,
the NRC should amend appendix K to 10 CFR part 50 to endorse the most
current industry consensus standard for decay heat power. The
petitioner notes that the National Technology Transfer and Advancement
Act of 1995 endorses the utilization of consensus technical standards
by Federal agencies. The petitioner further notes that the NRC recently
exercised Management Directive 6.5 by publishing a proposed rule (66 FR
40626; August 3, 2001) that would amend NRC regulations to incorporate
by reference the latest edition and recent addenda of the American
Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code.
The Amendment Would Allow Licensees Greater Operational Flexibility
Without Impacting Safety
The petitioner claims that its amendment would allow licensees to
gain operating margin for emergency core cooling system (ECCS)
equipment based on the more realistic decay heat assumptions in the
1994 standard. According to the petitioner, this would result in more
effective utilization of resources in operating and maintaining ECCS
equipment, and might also allow for higher extended power uprates. The
petitioner contends that safety would not be impacted because the
acceptance criteria for ECCS equipment would not be changed.
The Amendment Would Obviate the Need for Future Rulemakings To Codify
Methods and Practices Found Acceptable to the NRC
The petitioner's proposed amendment would give licensees the option
to adopt future NRC-approved revisions to the ANS standard without the
NRC having to undertake rulemakings to codify these subsequent
revisions.
[[Page 51886]]
The Petitioner's Conclusion
The petitioner maintains that its proposed amendment of appendix K
to 10 CFR part 50 would modernize the regulation by endorsing a
contemporary consensus standard that incorporates results from recent
data measurements and summation calculations.
The petitioner further argues that the proposed amendment is
consistent with NRC's Strategic Performance Goals. The NRC's strategic
performance goals are: (1) To maintain safety, protection of the
environment, and the common defense and security; (2) to increase
public confidence; (3) to make NRC activities and decisions more
effective, efficient, and realistic; and (4) to reduce unnecessary
regulatory burden on stakeholders.
The petitioner claims that its amendment would enhance nuclear
safety by basing decay heat curves and uncertainties on up-to-date data
measurements for specific fuel isotopes, allowing more accurate
decisions involving relative risk. According to the petitioner, the
amendment would also increase public confidence because the bases and
data relied upon in the latest ANS consensus standard are technically
accurate and reproducible. The petitioner maintains that adopting its
proposal would provide the NRC with sound and realistic technical bases
for make accurate decisions about decay heat power. Better decision-
making, says the petitioner, would allow the NRC staff to more
effectively allocate resources to other safety significant issues.
Finally, the petitioner claims that its proposed amendment would reduce
unnecessary technical burden on licensees, allowing them, in turn, to
expend their resources on other issues.
The petitioner states that, because the amendment would merely
codify the latest consensus standard on decay heat, a direct final rule
would be the most appropriate and cost-effective means of
implementation.
Dated at Rockville, Maryland, this 4th day of October, 2001.
For the Nuclear Regulatory Commission.
Annette L. Vietti-Cook,
Secretary of the Commission.
[FR Doc. 01-25565 Filed 10-10-01; 8:45 am]
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