[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