[Federal Register Volume 65, Number 8 (Wednesday, January 12, 2000)]
[Proposed Rules]
[Pages 1829-1830]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-725]


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NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[Docket No. PRM-50-68]


Bob Christie; 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 has received and requests 
public comment on a petition for rulemaking filed by Mr. Bob Christie, 
Performance Technology, Knoxville, Tennessee. The petition was docketed 
on November 15, 1999, and has been assigned Docket No. PRM-50-68. The 
petitioner requests that the NRC amend its regulations concerning 
hydrogen control systems at nuclear power plants. The petitioner 
believes that the current regulations on hydrogen control systems at 
some nuclear power plants are detrimental and present a health risk to 
the public. The petitioner believes that similar detrimental situations 
may apply to other systems as well (such as the requirement for a 10-
second diesel start time). The petitioner believes the proposed 
amendments would eliminate those situations that present adverse 
conditions at nuclear power plants.

DATES: Submit comments by March 27, 2000. Comments received after this 
date will be considered if it is practical to do so, but the Commission 
is able to assure consideration only for 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 David L. Meyer, 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 
website at http://ruleforum.llnl.gov. This site provides the capability 
to upload comments as files (any format), if your web browser supports 
that function. For information about the interactive rulemaking 
website, contact Ms. Carol Gallagher, (301) 415-5905 (e-
mail:[email protected]).
    The petition and copies of comments are also available 
electronically at the NRC's Public Electronic Reading Room on the 
Internet at http://www.nrc.gov/NRC/ADAMS/index.html. From this site, 
the public can gain entry into the NRC's Agencywide Document Access and 
Management System (ADAMS), which provides text and image files of NRC's 
public documents.
    The petition and copies of comments received may be inspected and 
copied for a fee at the NRC Public Document Room, 2120 L Street, NW. 
(Lower Level), Washington, DC.

FOR FURTHER INFORMATION CONTACT: David L. Meyer, Chief, Rules and 
Directives Branch, Division of Administrative Services, Office of 
Administration, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001, Telephone: 301-415-7162 or Toll Free: 1-800-368-5642 or 
email: DLM[email protected].

SUPPLEMENTARY INFORMATION:

Grounds for Petition

    The petitioner performed a detailed review of the San Onofre Task 
Zero Safety Evaluation Report (Pilot Program for Risk-Informed 
Performance-Based Regulation) conducted by the NRC staff and dated 
September 3, 1998, concerning that plant's hydrogen control system. The 
petitioner is convinced that action by the Commission is necessary to 
remedy possible adverse conditions at nuclear power plants.

Background

    The petitioner includes three topics of discussion in support of 
the proposed amendments:

A. Public Health Risk From Nuclear Electric Power Units

    The petitioner states that since the publication of the Reactor 
Safety Study (WASH-1400) in 1975, there has been a growing agreement 
between the practitioners of probabilistic risk assessment and 
licensing personnel (both at the NRC and within the industry) that 
there is a greater risk to public health from the release of fission 
products from the reactor core during a severe accident at a nuclear 
power plant, than from a design-basis accident. The petitioner asserts 
that the NRC staff has formally recognized this position. The 
petitioner sets out the following excerpts from the San Onofre Task 
Zero Safety Evaluation Report in support of his assertion.
    1. ``Subsequent risk studies have shown that the majority of risk 
to the public is from accident sequences that lead to containment 
failure or bypass, and that the contribution to risk from accident 
sequences involving hydrogen combustion is quite small.''
    2. ``As mentioned in the previous section, the risk associated with 
hydrogen combustion is not from design-basis accidents but from severe 
accidents.''
    3. ``The overall public risk and radiological consequences from 
reactor accidents is dominated by the more severe core damage accidents 
that involved containment failure or bypass.''

[[Page 1830]]

B. Consideration of Design-Basis Accidents

    The petitioner also states that since the publication of the 
Reactor Safety Study (WASH-1400) in 1975, there has been growing 
agreement between practitioners of probabilistic risk assessment and 
licensing personnel that compliance with some design-basis accident 
requirements can be detrimental to public health. The petitioner 
asserts that the NRC staff has formally recognized this position. The 
petitioner sets out the following excerpts from the San Onofre Task 
Zero Safety Evaluation Report in support of his assertion.
    1. ``Although the recombiners are effective in maintaining the 
Regulatory Guide 1.7 hydrogen concentration below the lower 
flammability limit of 4 volume percent, they are overwhelmed by the 
larger quantities of hydrogen associated with severe accidents which 
are typically released over a much shorter time period (e.g., 2 
hours).''
    2. ``From this information, the NRC staff concludes that the 
quantity of hydrogen, prescribed by 10 CFR 50.44(d) and Regulatory 
Guide 1.7, which necessitates the need for hydrogen recombiners and its 
backup, the hydrogen purge system is bounded by the hydrogen generated 
during a severe accident. The NRC staff finds that the relative 
importance of hydrogen combustion for large, dry containments with 
respect to containment failure to be quite low. This finding supports 
the argument that the hydrogen recombiners are insignificant from a 
containment integrity perspective.''
    3. ``In a postulated Loss of Coolant Accident, the San Onofre 
Nuclear Generating Station Units 2 and 3 Emergency Operating 
Instructions direct the control room operators to monitor and control 
the hydrogen concentration inside the containment after they have 
carried out the steps to maintain and control the higher priority 
critical safety functions. The key operator actions in controlling the 
hydrogen concentration are to place the hydrogen recombiners or 
hydrogen purge system in operation which involves many procedural 
steps. These hydrogen control activities could distract operators from 
more important tasks in the early phases of accident mitigation and 
could have a negative impact on the higher priority critical operator 
actions.''

C. Recommended Policy Statement on ``Design-Basis Accident Requirements 
Versus Severe Accident Information''

    The petitioner states that according to the San Onofre Safety 
Evaluation Report, the NRC granted an exemption to San Onofre from the 
design-basis accident requirements from the hydrogen control system on 
the basis of information obtained in the analysis of severe accidents. 
According to the petitioner, NRC staff's evaluation also indicated that 
adherence to the requirements of design-basis accidents could have a 
detrimental effect on public health. The petitioner asserts that it is 
likely that similar situations exist with respect to the hydrogen 
control systems at other nuclear units, and also for other systems at 
San Onofre and other nuclear units. The petitioner believes that the 
Commission should issue an interim policy statement concerning 
requirements for design-basis accidents. The petitioner believes that 
the interim policy statement would clarify the role of the NRC staff to 
ensure that matters that present a risk to public health are given 
appropriate high-level attention. The petitioner recommends the 
following ``strawman'' statement.

    All situations where there is an indication that adherence to 
design basis requirements would be detrimental to public health must 
be brought to the immediate attention of the Executive Director for 
Operations of the Nuclear Regulatory Commission. The Executive 
Director for Operations will make a decision on whether an exemption 
to the design basis requirements should be granted on an expedited 
basis.

    The petitioner believes that the NRC would want all individuals who 
may be aware of a situation where adherence to design-basis 
requirements could be adverse to public health, to bring the situation 
to the attention of the NRC staff without fear of recrimination and 
regardless of the present licensing basis for each nuclear unit. The 
petitioner states that, in the present culture of licensing at nuclear 
electric power units, there are few individuals (at the NRC or within 
the industry) who would suggest that adherence to design-basis accident 
requirements can be detrimental to safety. The petitioner believes that 
this culture must change and ``change with NRC blessings.''
    The petitioner states that he recommends an interim policy 
statement because the NRC, nuclear industry, and the public are in the 
process of changing the NRC regulations to eliminate situations where 
adherence to the regulations could present a risk to public health.
    The petitioner believes that the current regulations concerning 
combustible gas control systems have serious flaws and proposes that 10 
CFR 50.44 be revised to read as follows:

Section 50.44  Standards for Combustible Gas Control System in Light-
Water Cooled Power Reactors

    (a) An inerted reactor containment atmosphere shall be provided 
for each boiling light-water nuclear power reactor with a Mark I or 
Mark II type containment.
    (b) Each licensee with a boiling light-water nuclear power 
reactor with a Mark III type of containment and each licensee with 
an ice condenser type of containment shall provide its nuclear power 
reactor containment with a hydrogen control system. The hydrogen 
control system must be capable of handling (based on realistic 
calculations) the hydrogen equivalent to that generated from a 
metal-water reaction involving 75 percent of the fuel cladding 
surrounding the active fuel region (excluding the cladding 
surrounding the plenum volume).
    (c) All light-water reactors with other types of containment 
than those in paragraphs (a) or (b) of this section, must 
demonstrate that the reactor containment (based on realistic 
calculations) can withstand, without any hydrogen control system, a 
hydrogen burn for accidents with a high probability of causing 
severe reactor core damage. If such an evaluation of reactor 
containment capability can not be demonstrated, then the licensee 
shall provide a hydrogen control system per the backfit process. 
This hydrogen control system must be capable of handling (based on 
realistic calculations) the hydrogen equivalent to that generated 
from a metal-water reaction involving 75 percent of the fuel 
cladding surrounding the active fuel region (excluding the cladding 
surrounding the plenum volume).
    (d) Each light-water nuclear power reactor shall be provided 
with high point vents for the reactor coolant system, for the 
reactor vessel head, and for other systems required to maintain 
adequate reactor core cooling if the generation of noncondensible 
gases in these systems would realistically lead to severe reactor 
core damage during an accident. High point vents are not required, 
however, for the tubes in U-tube steam generators.

    The petitioner proposes that 10 CFR Part 50, Appendix A--General 
Design Criteria 41 be revised to read as follows:

Appendix A--General Design Criteria 41--Containment Atmosphere Cleanup

    As necessary, systems to control fission products, hydrogen, 
oxygen, and other substances which may be released into the reactor 
containment shall be provided, consistent with the functioning of 
other associated systems, to assure that reactor containment 
integrity is maintained for accidents where there is a high 
probability that fission products may be present in the reactor 
containment.

    Dated at Rockville, Maryland, this 6th date of January, 2000.

    For the Nuclear Regulatory Commission.
Annette L. Vietti-Cook,
Secretary of the Commission.
[FR Doc. 00-725 Filed 1-11-00; 8:45 am]
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