[Federal Register Volume 68, Number 68 (Wednesday, April 9, 2003)]
[Notices]
[Pages 17412-17414]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-8628]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-286]
Entergy Nuclear Operations, Inc., Indian Point Nuclear Generating
Unit No. 3; Exemption
1.0 Background
Entergy Nuclear Operations, Inc., (ENO or the licensee) is the
holder of Facility Operating License No. DPR-64 which authorizes
operation of the Indian Point Nuclear Generating Unit No. 3 (IP3). The
license provides, among other things, that the facility is subject to
all rules, regulations, and orders of the U.S. Nuclear Regulatory
Commission (NRC, the Commission) now or hereafter in effect.
The facility consists of a pressurized-water reactor located in
Westchester County in the State of New York.
2.0 Request/Action
Title 10 of the Code of Federal Regulations (10 CFR), part 50.44,
``Standards for combustible gas control system in light-water-cooled
power reactors,'' requires that each pressurized light-water nuclear
power reactor fueled with oxide pellets within cylindrical zircaloy or
ZIRLO cladding must be provided with the capability for controlling the
combustible gas concentrations in the containment following a
postulated loss-of-coolant accident (LOCA). A combustible gas control
system is defined by 10 CFR 50.44(h) as a system that operates after a
LOCA to maintain the concentrations of combustible gases within the
containment, such as hydrogen, below flammability limits. Combustible
gas control systems are of two types:
(1) Systems that allow controlled release from containment such as
a purge or vent system, and
(2) Systems that do not result in a significant release from
containment such as hydrogen recombiners. The combustible gas control
system at IP3 consists of a hydrogen recombiner system and a backup
purge system.
When IP3 was initially licensed, the post accident containment
ventilation (PACV) system was installed to meet the requirements of 10
CFR 50.44(f). Section 50.44(f) requires:
For facilities with respect to which the notice of hearing on
the application for a construction permit was published between
December 22, 1968, and November 5, 1970, if the incremental
radiation dose from purging (and repressurization if a
repressurization system is provided) occurring at all points beyond
the exclusion area boundary after a postulated LOCA calculated in
accordance with Sec. 100.11(a)(2) of this chapter is less than 2.5
rem to the whole body and less than 30 rem to the thyroid, and if
the combined radiation dose at the low population zone outer
boundary from purging and the postulated LOCA calculated in
accordance with Sec. 100.11(a)(2) of this chapter is less than 25
rem to the whole body and less than 300 rem to the thyroid, only a
purging system is necessary, provided that the purging system and
any filtration system associated with it are designed to conform
with the general requirements of Criteria 41, 42, and 43 of appendix
A to this part. Otherwise the facility shall be provided with
another type of combustible gas control system (a
[[Page 17413]]
repressurization system is acceptable) designed to conform with the
general requirements of Criteria 41, 42, and 43 of appendix A to
this part. If a purge system is used as part of the repressurization
system, the purge system shall be designed to conform with the
general requirements of Criteria 41, 42, and 43 of appendix A to
this part. The containment shall not be repressurized beyond 50
percent of the containment design pressure.
When the Commission issued what is now paragraph c(3)(ii) of 10 CFR
50.44 in 1981, a safety related hydrogen recombiner system was
installed. Paragraph c(3)(ii) requires:
By the end of the first scheduled outage beginning after July 5,
1982 and of sufficient duration to permit required modifications,
each light-water nuclear power reactor that relies upon a purge/
repressurization system as the primary means for controlling
combustible gases following a LOCA shall be provided with either an
internal recombiner or the capability to install an external
recombiner following the start of an accident. The internal or
external recombiners must meet the combustible gas control
requirements in paragraph (d) of this section. [* * *]
As a result, the recombiner system became the primary method of
combustible gas control while the PACV system became a backup method.
The purpose of this exemption request for 10 CFR 50.44(f) is to
remove requirements for the PACV system from the IP3 licensing basis.
The licensee is not requesting an exemption from GDC 41, ``Containment
Atmosphere Cleanup,'' or 10 CFR 50.44(c). The licensee is requesting
this exemption in accordance with 10 CFR 50.12. Pursuant to 10 CFR
50.12, the Commission may, upon application by any interested person or
upon its 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) when special
circumstances are present. These circumstances include the special
circumstances stated in 10 CFR 50.12(a)(2)(ii), ``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 PACV system also has a role in
severe accident management. The Commission stated in Attachment 1 to
SECY-02-0080, ``Proposed Rulemaking--Risk-Informed 10 CFR 50.44,
Combustible Gas Control In Containment,'' their position concerning the
ability to vent the containment as a severe accident strategy.
Specifically, Attachment 1 to SECY-02-0080 states:
The Commission continues to view severe accident management
guidelines as an important part of the severe accident closure
process. Severe accident management guidelines are part of a
voluntary industry initiative to address accidents beyond the design
basis and emergency operating instructions. In November 1994, the
U.S. nuclear industry committed to implement severe accident
management at their plants by December 31, 1998, using the guidance
contained in NEI 91-04, Revision 1, ``Severe Accident Issue Closure
Guidelines.'' Generic severe accident management guidelines
developed by each nuclear steam system supplier owners group
includes either purging and venting or venting the containment to
address combustible gas control. On the basis of the industry-wide
commitment, the Commission is not proposing to require such
capabilities, but continues to view purging and/or controlled
venting of all containment types to be an important combustible gas
control strategy that should be considered in a plant's severe
accident management guidelines.
3.0 Discussion
Pursuant to 10 CFR 50.12, the Commission may, upon application by
any interested person or upon its 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) when special circumstances are present. These circumstances include
the special circumstances that the PACV system is not needed to meet
the underlying purpose of 10 CFR 50.44. As mentioned above, the
underlying purpose of 10 CFR 50.44 is to show that following a LOCA, an
uncontrolled hydrogen-oxygen recombination would not take place, or
that the plant could withstand the consequences of uncontrolled
hydrogen-oxygen recombination without loss of safety function.
The staff examined the licensee's rationale to support the
exemption request of eliminating the licensing basis requirements for
the PACV system and concluded that retaining the licensing basis
requirements for the PACV system is not necessary to achieve the
underlying purpose of 10 CFR part 50.44. As mentioned above, the PACV
system is the backup combustible gas control system. The primary system
is the electric hydrogen recombiner system which meets the requirements
of 10 CFR 50.44 c(3)(ii). Each of the recombiner subsystems is capable
of maintaining the hydrogen concentration below the required limit
following a design-basis LOCA. The PACV system is not necessary to meet
the intent of the rule.
In their January 16, 2003, letter, the licensee stated that even
with the retirement of the PACV system, they will be able to meet all
their severe accident management commitments. Their current Severe
Accident Management Guidelines (SAMGs) identify, in addition to the
PACV system, three alternate methods of containment depressurization
and combustible gas control. These methods are backflow to the steam
ejector line, containment pressure relief line, and the containment
purge system. The licensee stated that the decommissioning of the PACV
system will include a revision to the SAMGs that will include the three
alternative methods listed above. The staff concludes that the licensee
continues to address the Commission's concerns regarding the use of
purging and/or controlled venting of containment as an important
combustible gas control strategy that should be considered in the
licensee's severe accident management guidelines.
Based on the above, the staff determined that the requested
exemption from the requirements of 10 CFR 50.44(f) meets the
requirements of 10 CFR 50.12. The staff finds the requested exemption
acceptable. Therefore, the staff concludes that pursuant to 10 CFR
50.12(a)(2) the licensee's requested exemption from the requirements of
10 CFR 50.44(f) for IP3 as specified in a letter dated October 3, 2002,
and as supplemented by letters dated January 16 and March 11, 2003, is
acceptable.
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 ENO an exemption from the
requirement to maintain a purge/repressurization system of 10 CFR
50.44(f) for IP3.
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 (68 FR 15487).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 2nd day of April, 2003.
[[Page 17414]]
For the Nuclear Regulatory Commission
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear
Reactor Regulation.
[FR Doc. 03-8628 Filed 4-8-03; 8:45 am]
BILLING CODE 7590-01-P