Dominion Nuclear Connecticut, Inc.; Millstone Power Station, Unit No. 2; Exemption, 8851-8855 [05-3398]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 70, Number 35 (Wednesday, February 23, 2005)]
[Notices]
[Pages 8851-8855]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-3398]


-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

[Docket No. 50-336]


Dominion Nuclear Connecticut, Inc.; Millstone Power Station, Unit 
No. 2; Exemption

1.0 Background

    Dominion Nuclear Connecticut, Inc. (DNC or the licensee) is the 
holder of Facility Operating License No. DPR-65, which authorizes 
operation of the Millstone Power Station, Unit No. 2 (MP2). The license 
provides, among other things, that the facility is subject to all 
rules, regulations, and orders of the Nuclear Regulatory Commission 
(NRC, the Commission) now or hereafter in effect.
    The facility consists of a pressurized water reactor located in New 
London County, Connecticut.

2.0 Request/Action

    By letter dated November 5, 2004, as supplemented by letters dated 
January 6 and January 25, 2005, the licensee submitted a request for an 
exemption from the requirements of title 10 of the Code of Federal 
Regulations (10 CFR) section 50.68(b)(1) for loading, unloading, and 
handling of the components of the Transnuclear (TN) NUHOMS[supreg]-32PT 
dry cask storage system at MP2.
    Section 50.68(b)(1) of 10 CFR 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.

    The licensee is unable to satisfy the above requirement for 
handling the 10 CFR part 72 licensed contents of the TN NUHOMS[supreg]-
32PT system. Section 50.12(a) allows licensees to apply for an 
exemption from the requirements of 10 CFR part 50 if the regulation is 
not necessary to achieve the underlying purpose of the rule and other 
conditions are met. The licensee stated in the application that 
compliance with 10 CFR 50.68(b)(1) is not necessary for

[[Page 8852]]

handling the 10 CFR part 72 licensed contents of the cask system to 
achieve the underlying purpose of 10 CFR 50.68(b)(1).

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. Therefore, in determining 
the acceptability of the licensee's exemption request, the staff has 
performed the following regulatory, technical, and legal evaluations to 
satisfy the requirements of 10 CFR 50.12 for granting the exemption.

3.1 Regulatory Evaluation

    The MP2 Technical Specifications (TSs) currently permit the 
licensee to store spent fuel assemblies in high-density storage racks 
in the MP2 spent fuel pool (SFP). In accordance with the provisions of 
10 CFR 50.68(b)(4), the licensee 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) of 10 CFR also requires that, 
if credit is taken for soluble boron, the keff must remain 
below 1.0 (subcritical) if flooded with unborated water. However, the 
licensee is unable to satisfy the requirement to maintain the 
keff below 1.0 (subcritical) with unborated water, which is 
also the requirement of 10 CFR 50.68(b)(1), during cask handling 
operations in the SFP. Therefore, the licensee's request for exemption 
from 10 CFR 50.68(b)(1) proposes to permit the licensee 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. It should be noted 
that an exemption from the requirements of 10 CFR 50.68(b)(4) is not 
necessary because it is only applicable to the spent fuel storage 
racks, which have been determined to be subcritical if flooded with 
unborated water.
    Part 50, Appendix A of 10 CFR, ``General Design Criteria (GDC) for 
Nuclear Power Plants,'' provides a list of the minimum design 
requirements for nuclear power plants. According to GDC-62, 
``Prevention of Criticality in Fuel Storage and Handling,'' the 
licensee must prevent criticality in the fuel handling and storage 
system by physical systems or processes.
    Section 50.68 of 10 CFR part 50, ``Criticality Accident 
Requirements,'' provides the NRC requirements for maintaining 
subcritical conditions in SFPs. Section 50.68 of 10 CFR provides 
criticality control requirements which, if satisfied, ensure that an 
inadvertent criticality in the SFP is an extremely unlikely event. 
These requirements ensure that the licensee has appropriately 
conservative criticality margins during handling and storage of spent 
fuel. Section 50.68(b)(1) of 10 CFR 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) ensures that the licensee will 
maintain the pool in a subcritical condition during handling and 
storage operations without crediting the soluble boron in the SFP 
water.
    The licensee has received a license to construct and operate an 
Independent Spent Fuel Storage Installation (ISFSI) at MP2. The ISFSI 
permits the licensee to store spent fuel assemblies in large concrete 
dry storage casks. As part of its ISFSI loading activities, the 
licensee transfers spent fuel assemblies to a dry shielded canister 
(DSC) in the cask pit area of the SFP. The licensee performed 
criticality analyses of the DSC fully loaded with fuel having the 
highest permissible reactivity, and determined that a soluble boron 
credit was necessary to ensure that the DSC would remain subcritical in 
the SFP. Since the licensee is 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, the 
licensee 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 staff evaluated the possibility of an inadvertent criticality 
of the spent nuclear fuel at MP2 during DSC loading, unloading, and 
handling. The staff has established a set of acceptance criteria that, 
if met, satisfy the underlying intent of 10 CFR 50.68(b)(1). In lieu of 
complying with 10 CFR 50.68(b)(1), the staff determined that an 
inadvertent criticality accident is unlikely to occur if the licensee 
meets the following five criteria:\1\
---------------------------------------------------------------------------

    \1\ The criteria have been used previously in the review of 
similar exemptions from the requirements of 10 CFR 50.68(b)(1) for 
Diablo Canyon Units No. 1 and 2 and Sequoyah Units No. 1 and 2. The 
evaluations for these exemptions are available in the Agencywide 
Documents Access and Management System under accession numbers 
ML040300693 and ML041540213, respectively.
---------------------------------------------------------------------------

    1. The cask criticality analyses are based on the following 
conservative assumptions:
    a. All fuel assemblies in the cask are unirradiated and at the 
highest permissible enrichment,
    b. Only 75 percent of the Boron-10 in the Boral panel inserts is 
credited,
    c. No credit is taken for fuel-related burnable absorbers, and
    d. The cask is assumed to be flooded with moderator at the 
temperature and density corresponding to optimum moderation.
    2. The licensee's ISFSI TS requires the soluble boron concentration 
to be equal to or greater than the level assumed in the criticality 
analysis and surveillance requirements necessitate the periodic 
verification of the concentration both prior to and during loading and 
unloading operations.
    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.
    4. The quantity of other forms of special nuclear material, such as 
sources, detectors, etc., to be stored in the cask will not increase 
the effective multiplication factor above the limit calculated in the 
criticality analysis.
    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. To demonstrate that it can safely identify 
and terminate a boron dilution event, the licensee must provide the 
following:
    a. A plant-specific criticality analysis to identify the critical 
boron concentration in the cask based on the highest reactivity loading 
pattern.
    b. A plant-specific boron dilution analysis to identify all 
potential dilution pathways, their flowrates, and the time necessary to 
reach a critical boron concentration.
    c. A description of all alarms and indications available to 
promptly alert operators of a boron dilution event.
    d. A description of plant controls that will be implemented to 
minimize the potential for a boron dilution event.
    e. A summary of operator training and procedures that will be used 
to ensure

[[Page 8853]]

that operators can quickly identify and terminate a boron dilution 
event.

3.2 Technical Evaluation

    In determining the acceptability of the licensee's exemption 
request, the staff reviewed three aspects of the licensee's analyses: 
(1) Criticality analyses submitted to support the ISFSI license 
application and its exemption request, (2) boron dilution analysis, and 
(3) legal basis for approving the exemption. For each of the aspects, 
the staff evaluated whether the licensee's analyses and methodologies 
provide reasonable assurance that adequate safety margins are developed 
and can be maintained in the MP2 SFP during loading of spent fuel into 
canisters for dry cask storage.
3.2.1 Criticality Analyses
    For evaluation of the acceptability of the licensee's exemption 
request, the staff reviewed the criticality analyses provided by the 
licensee in support of its ISFSI license application. Appendix M, 
Chapter 6, ``Criticality Evaluation,'' of the Standardized NUHOMS Final 
Safety Analysis Report (FSAR) contains detailed information regarding 
the methodology, assumptions, and controls used in the criticality 
analysis for the DSCs to be used at MP2. The staff reviewed the 
information contained in Chapter 6 as well as information provided by 
the licensee in its exemption request to determine if Criteria 1 
through 4 of Section 3.1 were satisfied.
    First, the staff reviewed the methodology and assumptions used by 
the licensee in its criticality analysis to determine if Criterion 1 
was satisfied. The licensee provided a detailed list of the assumptions 
used in the criticality analysis in Appendix M, Chapter 6 of the NUHOMS 
FSAR as well as in its exemption request. The licensee stated that it 
took no credit in the criticality analyses for burnup or fuel-related 
burnable absorbers. The licensee also stated that all assemblies were 
analyzed at the highest permissible enrichment.
    Additionally, the licensee stated that all criticality analyses for 
a flooded DSC were performed at temperatures and densities of water 
corresponding to optimum moderation conditions. In its supplemental 
response, dated January 25, 2005, the licensee provided the results of 
additional analyses it performed to determine the optimum moderation 
(i.e. maximum k\eff\) conditions in the DSC. The licensee, using 
previously approved methodologies, determined the optimum moderation 
condition occurred at 75 percent of full-water density in the DSC. The 
licensee determined that this condition would only occur during a 
boiling condition in the cask that resulted in significant voiding. The 
maximum design basis temperature for the MP2 SFP is 150 degrees 
Fahrenheit. Therefore, the cooling system in the SFP is designed to 
preclude reaching the conditions calculated in the optimum moderation 
analysis. This provides additional conservative margin in the 
criticality analysis.
    Finally, the licensee stated 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.'' In its review of the Standardized NUHOMS cask 
design, the staff reviewed and accepted the results of additional data 
supplied by the manufacturer which demonstrated that a 90-percent 
credit for the fixed neutron absorbers was acceptable in the TN 
NUHOMS[supreg]-32PT design. 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. 
Subsequently, based on its review of the criticality analyses contained 
in Appendix M, Chapter 6 of the NUHOMS FSAR and the information 
submitted in its exemption request, the staff finds that the licensee 
has satisfied Criterion 1.
    Second, the staff reviewed the proposed MP2 ISFSI TSs. The 
licensee'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, the licensee must have a 
conservative TS capable of ensuring that sufficient soluble boron is 
present to perform its safety function. The most limiting loading 
configuration of a DSC requires 2500 parts-per-million (ppm) of soluble 
boron to ensure the k\eff\ is maintained below 0.95, the regulatory 
limit relied upon by the staff for demonstrating compliance with the 
requirements of 10 CFR 72.124(a). MP2's ISFSI TSs require the soluble 
boron concentration in the DSC cavity to be greater than or equal to 
the concentrations assumed in the criticality analyses under a variety 
of DSC loading configurations. In all cases, the boron concentration 
required by the ISFSI TS ensures that the k\eff\ will be below 0.95 for 
the analyzed loading configuration. Additionally, the licensee's ISFSI 
TSs contain surveillance requirements which ensure it will verify that 
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 MP2 ISFSI TSs, the staff finds that the licensee has 
satisfied Criterion 2.
    Third, the staff reviewed the MP2 Updated Final Safety Analysis 
Report (UFSAR) and the information provided by the licensee 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. As a condition of receiving 
and maintaining an operating license, the licensee must comply with 
GDC-63. The staff reviewed the MP2 UFSAR and exemption request to 
determine whether it had provided sufficient information to demonstrate 
continued compliance with GDC-63. Based on its review of both 
documents, the staff finds that the licensee complies with GDC-63 and 
has satisfied Criterion 3.
    Finally, as part of the criticality analysis review, the staff 
evaluated the storage of non-fuel related material in a DSC. The 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[supreg]-32PT cask design 
are listed in the Standardized NUHOMS Certificate of Compliance (CoC) 
1004 Amendment 5 TSs. The contents have been reviewed for storage in 
the DSCs to be used at MP2 to ensure that subcritical conditions can be 
maintained. As such, MP2 is restricted to the storage of only those 
approved contents listed in the TSs. Additionally, the TSs restrict the 
loading patterns for storage of the approved contents. All of these 
controls ensure that the DSCs will remain subcritical under the most 
adverse conditions. Therefore, the staff determined that the loading 
limitations described in the CoC 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 staff finds that 
the licensee has satisfied Criterion 4.
3.2.2 Boron Dilution Analysis
    Since the licensee's ISFSI application relies on soluble boron to 
maintain subcritical conditions within the DSCs

[[Page 8854]]

during loading, unloading and handling operations, the staff reviewed 
the licensee'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.
    By letter dated October 25, 1996, the staff issued a safety 
evaluation (SE) of licensing topical report WCAP-14416, ``Westinghouse 
Spent Fuel Rack Criticality Analysis Methodology.'' This SE specified 
that the following issues be evaluated for applications involving 
soluble boron credit: the events that could cause boron dilution, the 
time available to detect and mitigate each dilution event, the 
potential for incomplete boron mixing, and the adequacy of the boron 
concentration surveillance interval.
    The TS requirements for the NUHOMS[supreg]-32PT Cask System include 
a minimum boron concentration requirement of 2500 ppm boron when spent 
fuel assemblies with enrichments less than or equal to 3.8 weight-
percent (wt-percent) U-235 are loaded into an DSC canister. For higher 
enrichments, a combination of poison rod assemblies (PRAs) and SFP 
soluble boron concentration are used to ensure subcritical conditions 
are maintained in the DSC. The quantity of PRAs needed is a function of 
the initial, unirradiated enrichment of the fuel assemblies to be 
loaded in the DSC. For the purposes of this exemption review, the 
limiting critical boron concentration was determined for the 3.8 wt-
percent enrichment loading with no PRAs. Therefore, the approval of 
this exemption is limited to the DSC loading, unloading, and handling 
of combustion engineering 14 x 14 fuel assemblies enriched to a maximum 
of 3.8 wt-percent U-235 and no PRAs. The NUHOMS soluble boron TS 
requirements ensure that k\eff\ is maintained less than 0.95. TS 
surveillance requirements require the boron concentration in the DSC 
water to be verified by two independent measurements within 4 hours 
prior to commencing any loading or unloading of fuel and verified every 
48 hours thereafter while the DSC is in the SFP when one or more fuel 
assemblies are installed.
    The licensee contracted with TN to perform a criticality analysis 
to determine the soluble boron concentration that results in a k\eff\ 
equal to 1.0 for 3.8 wt-percent U-235 fuel enrichments using the same 
methodology as approved in the Standardized NUHOMS Cask System Final 
Safety Analysis. The analysis determined the critical boron 
concentration level for 3.9 wt-percent U-235 enriched fuel was 1700 
ppm. The licensee selected 3.9 wt-percent U-235 enriched fuel as 
opposed to the 3.8 wt-percent limit in the TSs for added conservatism. 
The boron concentration within the canister would have to decrease from 
the TS limit to the critical boron concentration before criticality is 
possible. The licensee based its boron dilution analyses and its 
preventive and mitigative actions on dilution sources with the 
potential to reduce the boron concentration from the TS minimum value 
to the critical concentration.
    During the current analysis, the licensee referenced a previous 
analysis of the boron dilution event performed for MP2 and submitted to 
the NRC via letter on November 5, 2001. In this analysis the licensee 
identified all credible potential sources that could dilute the SFP to 
critical conditions. The licensee determined that the limiting boron 
dilution event occurs when primary make-up water (PMW), with a maximum 
flow rate of 200 gpm (gallons per minute), is added to the SFP. The 
licensee identified the following additional credible bounding dilution 
sources and their flow rates: 100 gpm from the auxiliary feedwater 
makeup to the SFP through an open valve directly to the SFP; 142 gpm 
from the reactor building closed component cooling water leaking to the 
SFP through a heat exchanger tube rupture; 93 gpm from a piping leak in 
the fire protection system, domestic water or the turbine building 
closed cooling water system. The staff found the scope and results of 
the dilution source evaluation acceptable.
    The licensee's calculations show that at least 5 hours will be 
available before the DSC water boron concentration decreases from 2500 
ppm to the critical concentration of 1700 ppm when a slug flow (no 
mixing) model is assumed.
    To demonstrate that sufficient time exists for plant personnel to 
identify and terminate a boron dilution event, the licensee provided a 
description of 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 an hour for 
a 200 gpm dilution rate. Since it would take an additional hour before 
the pool begin to overflow, at least 3 hours would be available for 
mitigation of the dilution. The staff finds that this is sufficient 
time to terminate the event before 1700 ppm in the DSC is reached.
    The configuration of the cask laydown pit in the pool could allow 
localized boron dilution and stratification because the pit is open to 
the SFP only through a narrow transfer path above the level of stored 
fuel. Addition of cold water directly to the cask loading area that is 
denser than the warm, borated pool water could fill the bottom of the 
cask pit with water having a low boron concentration. To avoid direct 
dilution to the cask pit area, the licensee has committed to include 
several requirements to its ISFSI operational procedures whenever a DSC 
is in the SFP with fuel inside. The procedures will require (1) 
verification that the opening of the cask pit is free from obstructions 
so that adequate flow between the SFP and the cask pit is established, 
(2) verification that the return isolation valve to the cask laydown 
pit is open, which will ensure adequate mixing and cooling within the 
cask pit area, thereby minimizing the possibility that boron 
stratification occurs, (3) continuous personnel presence on the SFP 
floor to promptly identify any inadvertent dilution that could cause 
stratification in the cask pit, and (4) maintaining 850 gpm of SFP 
cooling flow to establish adequate mixing throughout the pool.
    To ensure that operators are capable of identifying and terminating 
a boron dilution event during DSC loading, unloading, and handling 
operations, operator training will be conducted. The training will 
emphasize the importance of avoiding any inadvertent additions of 
unborated water to the SFP, responses to be taken for notifications or 
alarms that may be indicative of a potential boron dilution event 
during DSC loading and fuel movement, and identification of the 
potential for a boron dilution during decontamination activities.
    Based on the staff's review of the licensee's exemption request 
dated November 5, 2004, the supplemental information provided by 
letters dated January 6, and January 25, 2005, and its boron dilution 
analysis, the staff finds the licensee 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 not credible. Based on its review of the boron 
analysis and enhancements to the operating procedures and operator 
training program, the staff finds the licensee has satisfied Criterion 
5.
    Therefore, in conjunction with the conservative assumptions used to

[[Page 8855]]

establish the TS required boron concentration and critical boron 
concentration, the boron dilution evaluation demonstrates that the 
underlying intent of 10 CFR 50.68(b)(1) is satisfied.

3.3 Legal Basis for the Exemption

    Pursuant to 10 CFR 50.12, ``Specific Exemption,'' the staff 
reviewed the licensee's exemption request to determine if the legal 
basis for granting an exemption had been satisfied, and concluded that 
the licensee has satisfied the requirements of 10 CFR 50.12. With 
regard to the six special circumstances listed in 10 CFR 50.12(a)(2), 
the staff finds that the licensee's exemption request satisfies 
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.'' 
Specifically, the staff concludes that since the licensee has satisfied 
the five criteria in Section 3.1 of this exemption, the application of 
the rule is not necessary to achieve its underlying purpose in this 
case.

3.4 Summary

    The following limitations and/or conditions are applicable to this 
exemption:
    A. Loading, unloading, and handling of the DSC for the TN 
NUHOMS[supreg]-32PT shall only be done at MP2.
    B. Loading, unloading, and handling in the DSC at MP2 is limited to 
Combustion Engineering 14 x 14 fuel assemblies that had a maximum 
initial, unirradiated U-235 enrichment of 3.8 wt-percent.
    C. The licensee will implement the actions as stated in Attachment 
2 of its supplement dated January 25, 2005, namely:
    1. DNC will revise ISFSI procedures or calculations to state that 
poison rod assembly (PRA) use is not authorized by the proposed 10 CFR 
50.68(b)(1) exemption.
    2. DNC will revise ISFSI procedures to require that when a fueled 
32PT DSC is in the MPS2 [Millstone Power Station, Unit No. 2] SPF[,] 
Spent Fuel Pool Cooling Flow must be at least 850 gpm.
    3. During the time that a fueled DSC is in the SFP procedural 
controls will be implemented to ensure that the transfer canal bulkhead 
gate will not be used to block the transfer canal opening to the SFP.
    4. An additional precaution will be added to the SFP high level 
alarm response procedure to identify that if there is a fueled DSC in 
the SFP additional boron concentration limits apply. These limits will 
be specified in the procedure.
    5. Training will be conducted to ensure operators are aware of the 
32PT DSC TS SFP boron concentration requirements, and should a boron 
dilution occur, at what boron concentration criticality in the DSC 
could occur. The training will emphasize the importance of avoiding any 
inadvertent additions of unborated water to the SFP, responses to be 
taken for notification or alarms that may be indicative of a potential 
boron dilution event during cask loading and fuel movement in the SFP, 
and identification of the potential for a boron dilution event during 
decontamination rinsing activities.
    6. Appropriate controls or measures to minimize the possibility of 
direct dilution of the cask handling area of the SFP will be 
established prior to DSC loading.
    (a) DNC will revise ISFSI procedures to require an individual 
remain on the SFP floor at all times when a fueled 32PT DSC is in the 
MPS2 SFP to ensure that the SFP is not overflowing and that water is 
not unintentionally spilling into the SFP.
    (b) DNC will revise ISFSI procedures to require Valve 2-RW-350 [to] 
remain open when a fueled 32PT DSC is in the MPS2 SFP.
    (c) DSC procedures will be modified to include a requirement that 
the SFP will be sampled for boron concentration after each intentional 
addition of a maximum of 500 gallons of unborated water.
    7. DNC will revise ISFSI procedures to require [that] Valve 2-RW-2 
will be closed when a fueled 32PT DSC is in the MP2 SFP.
    The staff finds, based upon the review of the licensee's proposal 
to credit soluble boron during DSC loading, unloading, and handling in 
the MP2 SFP, that pursuant to 10 CFR 50.12(a)(2), the licensee's 
exemption request 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 Dominion Nuclear Connecticut, 
Inc. 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[supreg]-32PT dry cask storage system at MP2. Any changes to the 
cask system design features affecting criticality or its supporting 
criticality analyses will invalidate this exemption.
    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 (69 FR 2012).
    This exemption is effective upon issuance.

    Dated in Rockville, Maryland, this 15th day of February, 2005.

    For the Nuclear Regulatory Commission.
Ledyard B. Marsh,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. 05-3398 Filed 2-22-05; 8:45 am]
BILLING CODE 7590-01-P