Nuclear Management Company, LLC, Palisades Plant; Exemption, 60375-60379 [E5-5689]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 70, Number 199 (Monday, October 17, 2005)]
[Notices]
[Pages 60375-60379]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E5-5689]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-255]


Nuclear Management Company, LLC, Palisades Plant; Exemption

1.0 Background

    Nuclear Management Company, LLC (NMC) is the holder of Facility 
Operating License No. DPR-20, which authorizes operation of the 
Palisades Nuclear Plant (PNP). The license provides, among other 
things, that the facility is subject to all rules, regulations, and 
orders of the Nuclear Regulatory Commission (NRC or Commission) now or 
hereafter in effect.
    The facility consists of a pressurized-water reactor located in 
VanBuren County in Michigan.

2.0 Request/Action

    Title 10 of the Code of Federal Regulations 10 CFR part 50, Section 
50.68(b)(1) specifies requirements for handling and storing spent fuel 
assemblies during cask loading, unloading, and handling operations. 
Section 50.68(b)(1) sets forth the following requirement that must be 
met, in lieu of a monitoring system capable of detecting criticality 
events:

    Plant procedures shall prohibit the handling and storage at any 
one time of more fuel assemblies than have been determined to be 
safely subcritical under the most adverse moderation conditions 
feasible by unborated water.

    NMC is unable to satisfy the above requirement for handling the 10 
CFR part 72 licensed contents of the Transnuclear (TN) NUHOMS[reg]-32PT 
storage system. Section 50.12(a) allows licensees to apply for an 
exemption from the requirements of 10 CFR part 50, if special 
circumstances are demonstrated. NMC's letter of June 21, as 
supplemented August 25, 2005, requested a license exemption from the 
requirements of 10 CFR, part 50, Section 50.68(b)(1) for handling and 
storing spent fuel assemblies during cask loading, unloading, and 
handling operations for PNP. NMC stated in its letters that complying 
with 10 CFR 50.68(b)(1) is not necessary for handling the 10 CFR part 
72 licensed contents of the cask system to achieve the underlying 
purpose of the rule. Additionally, NMC contends that complying with the 
rule in this case will result in undue hardship.

3.0 Discussion

    Pursuant to 10 CFR 50.12, ``Specific Exemption,'' 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 circumstance listed in 
10 CFR 50.12(a)(2)(iii), where ``Compliance would result in undue 
hardship or other costs that are significantly in excess of those 
contemplated when the regulation was adopted, or that are significantly 
in excess of those incurred by others similarly situated.''
    In its exemption supplement of August 25, 2005, NMC provided a 
justification for satisfying the hardship special circumstance. The 
staff agrees with NMC that due to the short duration between the March 
23, 2005, issuance of Regulatory Issue Summary (RIS) 2005-05, 
``Regulatory Issues Regarding Criticality Analyses for Spent Fuel Pools 
and Independent Spent Fuel Storage Installations'' (ADAMS ML043500532), 
and the scheduled October 2005 cask loading campaign at PNP, 
insufficient time exists for NMC to perform the required analyses 
necessary to demonstrate compliance with 10 CFR 50.68. RIS 2005-05 
identified an acceptable methodology for demonstrating compliance with 
the 10 CFR 50.68(b)(1) requirements during cask loading, unloading, and 
handling operations in pressurized water reactor SFPs. The staff has 
determined that a hardship claim may be acceptable for licensees that 
have previously scheduled loading campaigns commencing before March 31, 
2006 (1 year after the issuance of the RIS). Therefore, the staff 
concludes that pursuant to 10 CFR 50.12(a)(2)(iii), NMC has provided 
sufficient justification to support a conclusion that undue hardship 
would occur if NMC were required to postpone its scheduled cask-loading 
campaign until it could comply with 10 CFR 50.68.
    However, since NMC's justification is based on the time needed to 
perform the necessary analyses, the staff has determined that NMC must 
comply with the regulations within an appropriate amount of time. In 
its exemption supplement, NMC proposed that the exemption remain valid 
until July 31, 2006. This will provide enough time for NMC to perform 
the necessary analyses and submit a license amendment request (LAR) to 
comply with 10 CFR 50.68. If NMC submits an LAR by July 31, 2006, this 
exemption will remain in effect until such time as the NRC staff either 
approves or denies the LAR. In this case, the NRC staff finds it 
acceptable to leave the exemption in effect because it will allow NMC 
to unload any previously loaded cask should it become necessary. 
However, if NMC does not submit a license amendment by July 31, 2006, 
this exemption will expire, and NMC will not be able to load, unload, 
or handle dry shielded canisters (DSCs) in the spent fuel pool (SFP). 
In its exemption supplement, NMC committed to complete supporting 
criticality analyses and submit a LAR to allow credit for burnup to 
meet the requirements of 10 CFR 50.68(b)(1) in July 2006 or earlier.
    The NRC staff also evaluated NMC's request to determine if NMC has 
provided reasonable assurance that it can conduct the proposed cask 
loading, unloading, and handling activities in a safe and effective 
manner. PNP's Technical Specifications (TSs) currently permit NMC to 
store spent fuel assemblies in high-density storage racks in its SFP. 
In accordance with the provisions of 10 CFR 50.68(b)(4), NMC takes 
credit for soluble boron for criticality control, and ensures that the 
effective multiplication factor (keff) of the SFP does not 
exceed 0.95 if flooded with borated water. Section 50.68(b)(4) also 
requires that if credit is taken for soluble boron, the keff 
must remain below 1.0 (subcritical) if flooded with unborated water. 
However, NMC is unable to satisfy the requirement to maintain the 
keff below 1.0 with unborated water at all times, which is 
also the requirement of 10 CFR 50.68(b)(1). Therefore, NMC's request 
for exemption from 10 CFR 50.68(b)(1) proposes to permit NMC to perform 
spent fuel loading, unloading, and handling operations related to dry 
cask storage without being subcritical under the most adverse 
moderation conditions feasible by unborated water.
    Appendix A, ``General Design Criteria (GDC) for Nuclear Power 
Plants,'' of 10 CFR, part 50, lists the minimum design

[[Page 60376]]

requirements for nuclear power plants. According to GDC 62, 
``Prevention of criticality in fuel storage and handling,'' PNP must 
have physical systems or processes to limit the potential for 
criticality in the fuel handling and storage system. Section 5.1.7.3 of 
PNP's Updated Final Safety Analysis Report (UFSAR) describes PNP's 
compliance with GDC 62. Section 5.1.7.3 specifically references the 
design of the spent fuel storage racks to maintain a geometrically safe 
configuration that provides spacing and neutron poisons sufficient to 
maintain a keff of less than 1.0 when flooded with unborated 
water.
    Section 50.68 of 10 CFR part 50, gives NRC requirements for 
maintaining subcritical conditions in SFPs. Section 50.68 specifies 
criticality-control requirements that, if satisfied, ensure that an 
inadvertent criticality in the SFP is an extremely unlikely event. 
These requirements include appropriate, conservative criticality 
margins during handling and storage of spent fuel. Section 50.68(b)(1) 
states, ``Plant procedures shall prohibit the handling and storage at 
any one time of more fuel assemblies than have been determined to be 
safely subcritical under the most adverse moderation conditions 
feasible by unborated water.'' Specifically, 10 CFR 50.68(b)(1) 
requires NMC to maintain the SFP in a subcritical condition during 
handling and storage operations without crediting the soluble boron in 
the SFP water.
    NMC received a license to construct and operate an Independent 
Spent Fuel Storage Installation (ISFSI) at PNP. The ISFSI permits NMC 
to store spent fuel assemblies in large concrete dry storage casks 
(Horizontal Storage Modules). As part of its ISFSI loading campaigns, 
NMC transfers spent fuel assemblies to a DSC in the cask pit area of 
the SFP. NMC performed criticality analyses of a fully-loaded DSC with 
fuel having the highest permissible reactivity. It determined that a 
soluble-boron credit was necessary to ensure that the DSC would remain 
subcritical in the SFP. NMC is thus unable to satisfy the requirement 
of 10 CFR 50.68(b)(1) to ensure subcritical conditions during handling 
and storage of spent fuel assemblies in the pool with unborated water. 
Accordingly, NMC identified the need for an exemption from the 10 CFR 
50.68(b)(1) requirement to support DSC loading, unloading, and handling 
operations, without being subcritical under the most adverse moderation 
conditions feasible by unborated water.
    The NRC staff evaluated the possibility of an inadvertent 
criticality of the spent nuclear fuel at PNP during DSC loading, 
unloading, and handling. The NRC staff has established a set of 
acceptance criteria that, if met, minimize the potential for an 
inadvertent criticality event. In lieu of complying with 10 CFR 
50.68(b)(1), the NRC staff determined that an inadvertent criticality 
accident is unlikely to occur if NMC meets the following five criteria:

 Criterion 1--The cask criticality analyses are based on the 
following conservative assumptions:
    --No credit is taken for fuel-related burnable absorbers.
    --All fuel assemblies in the cask are unirradiated and at the 
highest permissible enrichment.
    --The cask is assumed to be flooded with moderator at the 
temperature and density corresponding to optimum moderation.
    --Only 75 percent of the Boron-10 in the fixed poison panel inserts 
is credited.
 Criterion 2--NMC's ISFSI TSs require the soluble boron 
concentration to be equal to, or greater than, the level assumed in the 
criticality analysis. TS surveillance requirements specify periodically 
verifying the concentration both prior to, and during, loading and 
unloading operations.
 Criterion 3--Radiation monitors, as required by GDC 63, 
``Monitoring Fuel and Waste Storage,'' are provided in fuel storage and 
handling areas to detect excessive radiation levels and to initiate 
appropriate safety actions.
 Criterion 4--The quantity of other forms of special nuclear 
material (e.g., sources, detectors, etc.) to be stored in the cask will 
not increase the effective multiplication factor above the limit 
calculated in the criticality analysis.
 Criterion 5--Sufficient time exists for plant personnel to 
identify and terminate a boron dilution event prior to achieving a 
critical boron concentration in the DSC. NMC must provide the following 
to demonstrate that it can safely identify and terminate a boron 
dilution event:
    --A plant-specific criticality analysis to identify the critical 
boron concentration in the cask based on the highest reactivity loading 
pattern.
    --A plant-specific boron dilution analysis to identify all 
potential dilution pathways, their flowrates, and the time necessary to 
reach a critical boron concentration.
    --A description of all alarms and indications available to promptly 
alert operators of a boron dilution event.
    --A description of plant controls that NMC will implement to 
minimize the potential for a boron dilution event.
    --A summary of operator training, and procedures that will be used, 
to ensure that operators can quickly identify and terminate a boron 
dilution event.

    In RIS 2005-05, the NRC identified an acceptable methodology for 
demonstrating compliance with the 10 CFR 50.68(b)(1) requirements 
during cask loading, unloading, and handling operations in pressurized 
water reactor SFPs. The NRC staff has determined that licensee 
implementation of this methodology will eliminate the need to grant 
future exemptions for cask storage and handling evolutions. NMC 
submitted its exemption request on June 21, 2005, 3 months after the 
issuance of the RIS. Since the exemption request was submitted after 
the issuance of the RIS, and an acceptable methodology for complying 
with the regulation exists, the staff has determined that it is not 
appropriate to approve the exemption based on the 50.12(a)(2)(ii) 
special circumstance related to the underlying purpose of the rule.
    In its August 25, 2005, supplement, NMC contends that due to the 
short duration available between the March 2005 issuance of the RIS, 
and the October 2005 planned cask loading campaign, an undue hardship 
exists. Section 50.12 of 10 CFR provides for a special circumstance 
that allows the staff to review an exemption request based on undue 
hardship. Specifically, 10 CFR 50.12(a)(2)(iii) states the following:

    Compliance would result in undue hardship or other costs that 
are significantly in excess of those contemplated when the 
regulation was adopted, or that are significantly in excess of those 
incurred by others similarly situated.

    Since the NRC staff has determined that it is not appropriate to 
grant the exemption based on satisfying the underlying intent of the 
rule, it reviewed the exemption request based on the undue hardship 
special circumstance in 10 CFR 50.12(a)(2)(iii). In determining the 
technical acceptability of NMC's exemption request, the NRC staff 
reviewed NMC's criticality analyses submitted to support the ISFSI 
license application and its exemption request, and NMC's boron dilution 
analysis. For each of the aspects, the NRC staff evaluated whether 
NMC's analyses and methodologies provide reasonable

[[Page 60377]]

assurance that adequate safety margins are developed, and can be 
maintained, in the PNP SFP during loading of spent fuel into DSCs for 
dry cask storage.

3.1 Criticality Analyses

    The NRC staff's review of NMC's criticality analyses, as described 
in the Standardized NUHOMS[reg] Fuel Safety Analysis Report, dated 6/
30/04 (ADAMS ML051040570), consists of four parts. First, the NRC staff 
reviewed the methodology and assumptions NMC used in its criticality 
analysis to determine if Criterion 1 was satisfied. NMC stated the 
following:

 It took no credit in the criticality analyses for burnup or 
fuel-related burnable neutron absorbers.
 All assemblies were analyzed at the highest permissible 
enrichment.
 All criticality analyses for a flooded DSC were performed at 
temperatures and densities of water corresponding to optimum moderation 
conditions.

    In its exemption request, NMC provided the results of its optimum 
moderation analysis that effectively demonstrated that the optimum 
moderation condition had been identified. NMC also said that it 
credited 90 percent of the Boron-10 content for the fixed neutron 
absorber in the DSC. NUREG-1536, ``Standard Review Plan for Dry Cask 
Storage System,'' states that ``[f] or a greater credit allowance 
[i.e., greater than 75 percent for fixed neutron absorbers] special, 
comprehensive fabrication tests capable of verifying the presence and 
uniformity of the neutron absorber are needed.'' The NRC staff accepted 
a 90-percent credit for the fixed neutron absorbers as described in 
Section 6 of Appendix M of the Standardized NUHOMS[reg] Final Safety 
Analysis Report. Therefore, for the purposes of this exemption, the 
staff finds a 90-percent credit acceptable on the basis that it has 
previously been reviewed and approved by the NRC. Based on its review 
of the criticality analyses and the information submitted in its 
exemption request, the NRC staff finds that NMC has satisfied Criterion 
1.
    Second, the NRC staff reviewed the proposed PNP ISFSI TSs. NMC's 
criticality analyses credit soluble boron for reactivity control during 
DSC loading, unloading, and handling operations. Since the boron 
concentration is a key safety component necessary for ensuring 
subcritical conditions in the pool, NMC must have a conservative ISFSI 
TS capable of ensuring that sufficient soluble boron is present to 
perform its safety function. The ISFSI TSs applicable to the 
NUHOMS[reg]-32PT DSC, and attached to the Certificate of Compliance No. 
1004, contain the requirements for the minimum soluble boron 
concentration as a function of fuel assembly class, DSC basket type, 
and corresponding assembly average initial enrichment values. In all 
cases, the boron concentration required by the ISFSI TS ensures that 
the keff will be below 0.95 for the analyzed loading 
configuration. Additionally, NMC's ISFSI TSs contain surveillance 
requirements that assure it will verify the boron concentration is 
above the required level both prior to, and during, DSC loading, 
unloading, and handling operations. Based on its review of the PNP 
ISFSI TSs, the NRC staff finds that NMC has satisfied Criterion 2.
    Third, the NRC staff reviewed the PNP's UFSAR, and the information 
provided by NMC in its exemption request, to ensure that it complies 
with GDC 63. GDC 63 requires that licensees have radiation monitors in 
fuel storage and associated handling areas to detect conditions that 
may result in a loss of residual heat removal capability and excessive 
radiation levels and initiate appropriate safety actions. In its 
exemption request, NMC stated that its radiation monitoring system 
consists of gamma-sensitive detector assemblies in the SFP area, with 
audible alarm at the initiating detector and in the main control room. 
NMC stated in its exemption request that operations personnel will 
investigate the cause of high radiation levels and initiate appropriate 
safety actions. Furthermore, NMC's compliance with GDC 63 is described 
in its UFSAR, Sections 5.1.7.4 and 9.11.4.4. Based on its review of the 
exemption request and the PNP UFSAR, the NRC staff finds that NMC has 
satisfied Criterion 3.
    Fourth, as part of the criticality analysis review, the NRC staff 
evaluated the storage of non-fuel related material in a DSC. The NRC 
staff evaluated the potential to increase the reactivity of a DSC by 
loading it with materials other than spent nuclear fuel and fuel 
debris. The approved contents for storage in the NUHOMS[reg]-32PT cask 
design are listed in the PNP ISFSI TS Limiting Condition for Operation 
(LCO) 1.2.1 ``Fuel Specifications.'' This ISFSI TS LCO restricts the 
contents of the DSC to only fuels and non-fissile materials irradiated 
at PNP. As such, PNP is prohibited from loading other forms of special 
nuclear material (e.g., sources, detectors, etc.) in the DSC. 
Therefore, the NRC staff determined that the loading limitations 
described in PNP's ISFSI TSs will ensure that any authorized components 
loaded in the DSCs will not result in a reactivity increase. Based on 
its review of the loading restrictions, the NRC staff finds that NMC 
has satisfied Criterion 4.

3.2 Boron Dilution Analysis (Criterion 5)

    Since NMC's ISFSI application relies on soluble boron to maintain 
subcritical conditions within the DSCs during loading, unloading, and 
handling operations, the NRC staff reviewed NMC's boron dilution 
analysis to determine whether appropriate controls, alarms, and 
procedures were available to identify and terminate a boron dilution 
accident prior to reaching a critical boron concentration.
    The NRC's letter of October 25, 1996, ``Topical Report Evaluation 
of WCAP-14416, Westinghouse Spent Fuel Rack Criticality Analysis 
Methodology'' (ADAMS 9610300008), issued a safety evaluation 
on licensing topical report WCAP-14416, ``Westinghouse Spent Fuel Rack 
Criticality Analysis Methodology.'' This safety evaluation specified 
that the following issues be evaluated for applications involving 
soluble boron credit:
     Events that could cause boron dilution;
     Time available to detect and mitigate each dilution event;
     Potential for incomplete boron mixing;
     Adequacy of the boron concentration surveillance interval.
    The criticality analyses performed for the NUHOMS[reg]-32PT DSC are 
described in the FSAR for the Standardized NUHOMS[reg] Horizontal 
Modular Storage System for Irradiated Nuclear Fuel. NMC used the same 
criticality analysis methods, models, and assumptions for its boron 
dilution evaluation. These PNP criticality calculations are based on 
the KENO V.a code. The calculations determined the minimum soluble 
boron concentration required to maintain subcriticality 
(keff < 1.0) following a boron dilution event in a 
NUHOMS[reg]-32PT DSC loaded with fuel assemblies that bound the PNP 
fuel designs (Combustion Engineering 15 x 15 fuel). To ensure that the 
calculated critical boron concentrations were bounding for all loading 
conditions, NMC employed conservative fuel enrichments in its analysis. 
NMC's criticality analyses were based on 3.6 weight-percent Uranium-235 
enriched fuel, as opposed to the 3.4 weight percent limit in the 
NUHOMS[reg]-32PT DSC TSs. The results of these calculations for the 
bounding case indicate that subcriticality is maintained if the soluble 
boron concentration remains greater than or equal to 1850 ppm. PNP's 
ISFSI TSs

[[Page 60378]]

require NMC to maintain the soluble boron concentration greater than 
2500 ppm in the DSC at all times. NMC indicated that proposed Amendment 
9 to the NUHOMS[reg] Certificate of Compliance 1004 provides analyses 
to support a variable, minimum-required, soluble-boron concentration as 
a function of the initial enrichment of the fuel to be stored. NMC 
committed in its exemption request to not implement this proposed 
change. Instead, NMC will continue to conduct DSC operations at a boron 
concentration of greater than or equal to 2500 ppm.
    TS surveillance requirements for the NUHOMS[reg]-32PR Cask System 
require the boron concentration in the SFP, and in the water to be 
introduced in the DSC, to be verified as follows:
     Within 4 hours prior to flooding the DSC cavity;
     Within 4 hours prior to inserting the first spent fuel 
assembly into the DSC;
     Reconfirmed at intervals not to exceed 48 hours until such 
time as the DSC is removed from the SFP;
    NMC's analysis identified all credible potential sources that could 
dilute the SFP to critical conditions. NMC determined that the limiting 
boron dilution event occurs when water from the fire protection system, 
with a maximum flow rate of 210 gpm from a 1.5-inch diameter hose, is 
added to the SFP. NMC's calculations show that at least 4 hours will be 
available to terminate the event before the DSC water boron 
concentration decreases from 2500 ppm to the critical concentration of 
1850 ppm, assuming a straight dilution to the SFP overflow limit and a 
feed and bleed operation thereafter with instantaneous complete mixing.
    The Palisades' SFP is a large rectangular structure filled with 
borated water which completely covers the spent fuel assemblies. During 
loading, unloading, and handling activities, the DSC is located in a 9 
by 9 foot area in the north east corner of the SFP. This area is open 
to the SFP, thereby ensuring that thermal currents within the pool will 
mix the volume near the DSC with the remainder of the pool.
    To demonstrate that sufficient time exists for plant personnel to 
identify and terminate a boron dilution event, NMC described all alarms 
available to alert operators, and plant controls that will be 
implemented. There is no automatic level control system for the SFP; 
therefore, the SFP will overflow on an uncontrolled water addition. 
However, a high-level alarm in the control room would alert personnel 
of a potential boron dilution event within 45 minutes for a 210 gpm 
dilution rate; 30 additional minutes will elapse before the pool begins 
to overflow. From this point, NMC calculated that at least 3 more hours 
are available to mitigate the dilution event before the boron 
concentration is reduced to the critical concentration of 1850 ppm.
    In its exemption request of June 21, 2005, NMC stated that ``to 
ensure defense-in-depth regarding the detection of a boron dilution 
event, NMC will revise procedures to include a requirement that 
whenever a 32PT DSC is in the SFP and fuel is in the DSC, the SFP level 
will be monitored on at least an hourly frequency (via television 
monitor or locally) to ensure that the SFP is not overflowing, and that 
SFP water level is not unintentionally rising.'' Therefore, should a 
boron dilution event occur, the most conservative time for the 
individual to detect the event would be when the SFP begins to 
overflow. Assuming the pool water level starts just above the low-level 
alarm setpoint, then at most 73.3 minutes could elapse since the start 
of the dilution. With a limiting value of 210 gpm of unborated water 
being added to the pool, there would be 2.96 additional hours to 
mitigate and terminate the event. The staff finds that this is 
acceptable.
    To ensure that operators are capable of identifying and terminating 
a boron dilution event during DSC loading, unloading, and handling 
operations, NMC stated that operator training will be conducted. NMC 
said that during training activities, operators will receive revised 
alarm manual procedures, which verify that the SFP boron concentration 
is in compliance with the new ISFSI TS limit prior to the loading of a 
NUHOMS[reg]-32PR DSC.
    Based on the staff's review of NMC's exemption request dated June 
21, 2005, and its boron dilution analysis, the staff finds that NMC has 
provided sufficient information to demonstrate that an undetected and 
uncorrected dilution from the TS required boron concentration to the 
calculated critical boron concentration is very unlikely. Based on its 
review of the boron analysis and enhancements to the operating 
procedures and operator training program, the staff finds NMC has 
satisfied Criterion 5.
    Therefore, in conjunction with the conservative assumptions used to 
establish the TS-required boron concentration and critical boron 
concentration, the boron dilution evaluation demonstrates that the SFP 
and DSC will remain subcritical during spent fuel loading, unloading 
and handling operations.
    Accordingly, the NRC staff concludes that since NMC has satisfied 
the five criteria, as described in Section 3.0 of this exemption, NMC 
has provided reasonable assurance that it can conduct the proposed cask 
loading, unloading, and handling activities in a safe and effective 
manner.
    Section 50.68(b)(1) of 10 CFR was promulgated to require that 
adequate controls are in place so that the handling and storage of fuel 
assemblies is conducted in a manner that provides reasonable assurance 
that the fuel assemblies will remain safely subcritical. Based on the 
NRC staff's review of NMC's exemption request, the staff has determined 
the following:
     NMC has demonstrated that sufficient controls are in place 
to provide reasonable assurance that there is no undue risk to public 
health and safety given conservative assumptions in the criticality 
analysis (Criterion 1).
     Surveillances periodically verify the boron concentration 
before, and during, loading and unloading (Criterion 2).
     Radiation monitoring equipment is used to detect excessive 
radiation and initiate appropriate protective actions (Criterion 3).
    Only fuel authorized by the ISFSI TSs will be loaded and stored in 
the ISFSI (Criterion 4).
     Boron dilution events have been analyzed, and there are 
sufficient monitoring capabilities and time for NMC to identify and 
terminate a dilution event prior to achieving a critical boron 
concentration in the cask (Criterion 5).
    Therefore, the NRC staff concludes that NMC has established 
sufficient controls to ensure the fuel assemblies remain subcritical 
during loading, unloading, and handling within the SFP and DSC so that 
there is no undue risk to public health and safety.
    This exemption results in changes to the operation of the plant by 
allowing the operation of the new dry fuel storage facility and loading 
of the NUHOMS[reg]-32PT DSC.

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 NMC, an exemption from the 
requirements of 10 CFR 50.68(b)(1) for the loading, unloading, and 
handling of the components of the TN NUHOMS[reg]-32PT

[[Page 60379]]

dry cask storage system at PNP. However, since NMC does not have an 
NRC-approved methodology for evaluating changes to the analyses or 
systems supporting this exemption request, the NRC staff's approval of 
the exemption is restricted to those specific design and operating 
conditions described in NMC's June 21, 2005, exemption request. NMC may 
not apply the 10 CFR 50.59 process for evaluating changes to specific 
exemptions. Any changes to the design or operation of (1) the dry cask 
storage system; (2) the SFP; (3) the fuel assemblies to be stored; (4) 
the boron dilution analyses; or (5) supporting procedures and controls, 
regardless of whether they are approved under the general Part 72 
license or perceived to be conservative, will invalidate this 
exemption. Upon invalidation of the exemption, NMC will be required to 
comply with NRC regulations prior to future cask loadings.
    Based upon the review of NMC's exemption request to credit soluble 
boron during DSC loading, unloading, and handling in PNP's SFP, the NRC 
staff concludes that pursuant to 10 CFR 50.12(a)(2)(iii), NMC's 
exemption request is acceptable. However, the NRC staff places the 
following limitations/conditions on the approval of this exemption:
    1. This exemption is limited to the loading, unloading, and 
handling of the DSC for only the TN NUHOMS[reg]-32PT at the PNP.
    2. This exemption is limited to the loading, unloading, and 
handling in the DSC at PNP of Combustion Engineering 15 x 15 fuel 
assemblies, without burnable poison rod assemblies, that had maximum 
initial, unirradiated U-235 enrichments less than 3.6 weight percent.
    3. This exemption is limited to the one-time only loading, 
unloading, and handling of the 7 TN NUHOMS[reg]-32PT cask systems (224 
assemblies total) scheduled for the October 2005 cask loading campaign 
at PNP.
    4. If NMC submits a LAR by July 31, 2006, this exemption will 
remain in effect until such time as the NRC staff either approves or 
denies the LAR. In this case, the NRC staff finds it acceptable to 
leave the exemption in effect because it will allow NMC to unload any 
previously loaded cask should it become necessary. However, if NMC does 
not submit a license amendment by July 31, 2006, this exemption will 
expire, and NMC will not be able to load, unload, or handle DSCs in the 
SFP. In its exemption supplement, NMC committed to complete supporting 
criticality analyses and submit a LAR to allow credit for burnup to 
meet the requirements of 10 CFR 50.68(b)(1) in July 2006 or earlier.
    5. During DSC loading, unloading, and handling at PNP, the SFP 
soluble boron concentration must be greater than or equal to 2500 ppm 
at all times.
    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 (70 FR 57899).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 6th day of October 2005.

    For the Nuclear Regulatory Commission.

Ledyard B. Marsh,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. E5-5689 Filed 10-14-05; 8:45 am]
BILLING CODE 7590-01-P