[Federal Register Volume 85, Number 122 (Wednesday, June 24, 2020)]
[Notices]
[Pages 37965-37968]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-13651]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-254 and 50-265; NRC-2020-0143]


Exelon Generation Company, LLC and MidAmerican Energy Company 
Quad Cities Nuclear Power Station, Units 1 and 2

AGENCY: Nuclear Regulatory Commission.

ACTION: Exemption; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) has issued an 
exemption in response to a July 22, 2019, request from Exelon 
Generation Company, LLC, from certain regulatory requirements in order 
to permit exclusion of main steam isolation valve (MSIV) leakage from 
the overall integrated leak rate Type A test measurement and MSIV 
pathway leakage contributions from the combined leakage rate of all 
penetrations and valves subject to Type B and Type C tests.

DATES: The exemption was issued on June 18, 2020.

ADDRESSES: Please refer to Docket ID NRC-2020-0143 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly-available information related to this document 
using any of the following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2020-0143. Address 
questions about NRC docket IDs in Regulations.gov to Jennifer Borges; 
telephone: 301-287-9127; email:

[[Page 37966]]

[email protected]. For technical questions, contact the 
individual listed in the FOR FURTHER INFORMATION CONTACT section of 
this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly-available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or 
by email to [email protected]. The ADAMS accession number for each 
document referenced (if it is available in ADAMS) is provided the first 
time that it is mentioned in this document.

FOR FURTHER INFORMATION CONTACT: Robert F. Kuntz, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001; telephone: 301-415-3733, email: [email protected].

SUPPLEMENTARY INFORMATION: The text of the exemption is attached.

    Dated: June 19, 2020.

    For the Nuclear Regulatory Commission.
Russell S. Haskell,
Project Manager, Plant Licensing Branch III, Division of Operating 
Reactor Licensing, Office of Nuclear Reactor Regulation.

Attachment--Exemption

NUCLEAR REGULATORY COMMISSION

Docket Nos. 50-254 and 50-265

Exelon Generation Company, LLC and MidAmerican Energy Company Quad 
Cities Nuclear Power Station, Units 1 and 2

Exemption

I. Background

    Exelon Generation Company, LLC (EGC, the licensee) and 
MidAmerican Energy Company are the holders of Facility Operating 
License Nos. DPR-29 and DPR-30, which authorize operation of the 
Quad Cities Nuclear Power Station (QCNPS), Units 1 and 2. The 
licenses provide, among other things, that the facilities are 
subject to the rules, regulations, and orders of the U.S. Nuclear 
Regulatory Commission (NRC, the Commission) now or hereafter in 
effect. The facilities each consist of a boiling, light-water 
reactor located in Rock Island County, Illinois.

II. Request/Action

    In its letter dated March 5, 2019 (Agencywide Documents and 
Access Management System (ADAMS) Accession No. ML19064B369), as 
supplemented by letters dated May 23, 2019 (ADAMS Accession No. 
ML19143A347), July 22, 2019 (ADAMS Accession No. ML19203A176), 
February 24, 2020 (ADAMS Accession No. ML20055E826), and March 31, 
2020 (ADAMS Accession No., ML20091H576) EGC requested a permanent 
exemption from the Part 50 of Title 10 of the Code of Federal 
Regulations (10 CFR), Appendix J, Option B, Section III.A 
requirements in order to permit exclusion of main steam isolation 
valve (MSIV) leakage from the overall integrated leak rate Type A 
test measurement, and from Option B, Section III.B, requirements in 
order to permit exclusion of the MSIV pathway leakage contributions 
from the combined leakage rate of all penetrations and valves 
subject to Type B and Type C tests. The letters also requested 
license amendments to revise Technical Specification (TS) 3.6.1.3, 
``Primary Containment Isolation Valves (PCIVs),'' Surveillance 
Requirement (SR) 3.6.1.3.10 that would increase the single and 
combined MSIV leakage rate limits; add a new TS 3.6.2.6, ``Residual 
Heat Removal (RHR) Drywell Spray,'' to reflect the crediting of 
drywell spray for fission product removal; and revise TS 3.6.4.1, 
``Secondary Containment,'' SR 3.6.4.1.1 to address short-duration 
conditions during which the secondary containment pressure may not 
meet the SR pressure requirement at QCNPS, Units 1 and 2. The 
license amendment requests are addressed separately.
    Under Part 50 of 10 CFR, paragraph 50.54(o), primary reactor 
containments for water-cooled power reactors are subject to the 
requirements of Appendix J to 10 CFR part 50. Appendix J specifies 
the leakage rate test requirements, schedules, and acceptance 
criteria for tests of the leak-tight integrity of the reactor 
containment, and systems and components that penetrate the 
containment. Option B of 10 CFR 50, Appendix J, ``Performance-Based 
Requirements,'' paragraph III.A, ``Type A Test,'' requires, among 
other things, that the overall integrated leakage rate must not 
exceed the allowable leakage rate (La) with margin, as 
specified in the TSs. The overall integrated leakage rate is defined 
in 10 CFR part 50, Appendix J, as ``the total leakage rate through 
all tested leakage paths, including containment welds, valves, 
fittings, and components that penetrate the containment system.'' 
This includes the contribution through the four main steam (MS) 
lines where each line contains two MSIVs in series. Paragraph III.B, 
``Type B and C Tests,'' requires, among other things, that the sum 
of the leakage rates of Type B and Type C local leakage rate tests 
be less than the performance criterion (La) with margin 
as specified in the TSs. The allowable leakage rates set in the TSs 
ensure that the required dose limits, such as in 10 CFR 50.67, 
``Accident source term,'' will not be exceeded.
    This requested exemption concerns the MS system, which 
penetrates containment. The licensee requested this exemption 
because the MS pathway leakage is treated separately from the 
remainder of the assumed leakage from primary containment in the 
design basis loss of coolant accident (LOCA) analysis. The 
radiological consequences of MSIV leakage are modeled as a separate 
primary containment release path to the environment that bypasses 
secondary containment, and therefore, it is not filtered through the 
standby gas treatment system like other containment leakage. The 
design basis LOCA dose calculation assumes all MSIV leakage migrates 
to the turbine building and then to the environment. By currently 
including the MS pathway leakage with the rest of the primary 
containment leakage test results, it is being accounted for twice--
once as part of the actual containment leakage and again as part of 
the MSIV leakage used in the LOCA dose calculations.

III. 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 as described in 10 
CFR 50.12(a)(2)(i)-(vi) are present. The licensee asserted that 
special circumstances are present under 10 CFR 50.12(a)(2)(ii) 
(stating that the 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 licensee's exemption request was submitted with license 
amendments request to increase the allowable MSIV leakage rate. The 
exemption and amendments together will permit an increase in 
allowable MSIV leakage rate that is excluded from the overall 
integrated leak rate Type A test measurement and excluded from the 
combined Type B and Type C test total. The licensee described its 
view on the special circumstances associated with the MSIV leakage 
path testing in its application dated July 22, 2019.

A. The Exemption Is Authorized by Law

    This exemption permits exclusion of the MSIV pathway leakage 
contribution from the overall integrated leakage rate Type A test 
measurement and from the combined leakage rate of all penetrations 
and valves subject to Type B and Type C tests. As stated above, 10 
CFR 50.12 allows the NRC to grant exemptions from the requirements 
of 10 CFR part 50. The NRC staff has determined that granting of the 
licensee's proposed exemption will not result in a violation of the 
Atomic Energy Act of 1954, as amended, or the Commission's 
regulations. Therefore, the exemption is authorized by law.

B. The Exemption Presents No Undue Risk to Public Health and Safety

    Type A tests to measure the containment system overall 
integrated leakage rate must be conducted under conditions 
representing design basis LOCA containment peak pressure. Type B 
pneumatic tests to detect and measure local leakage rates across 
pressure retaining, leakage-limiting boundaries, and Type C 
pneumatic tests to measure containment isolation valve leakage 
rates, must be conducted to ensure the integrity of the overall 
containment system as a barrier to fission product release to reduce 
the risk from reactor accidents.
    In license Amendment Nos. 233 and Amendment 229 (ADAMS Accession 
No. ML062070290), the NRC approved the use of the alternative source 
term (AST) (as

[[Page 37967]]

prescribed in 10 CFR 50.67) in the calculations of the radiological 
dose consequences of design basis accidents (DBAs), including the 
design basis LOCA, for QCNPS, Units 1 and 2. The NRC staff safety 
evaluation accompanying these amendments acknowledged that once 
fission products are dispersed in the primary containment, their 
release to the environment is assumed to occur through three 
pathways: (1) The leakage of primary containment atmosphere; (2) the 
leakage of primary containment atmosphere through MSIVs; and (3) the 
leakage from emergency core cooling systems that recirculate 
suppression pool water outside of the primary containment. As noted 
above, however, leakage through the MSIVs is considered a separate 
pathway and is calculated as a separate contributor to the dose 
consequence analysis. As such, the inclusion of MSIV leakage as part 
of Type A and as part of Type B and C test results is not necessary 
to ensure the actual radiological consequences of DBAs remain below 
the regulatory limit.
    The proposed exemption does not create any new accident 
precursors. Therefore, the probability of postulated accidents is 
not increased. Also, the consequences of postulated accidents are 
not significantly changed from the previously evaluated consequences 
associated with the design basis LOCA as described in the AST 
amendments. Therefore, there is no undue risk to public health and 
safety.

C. The Exemption Is Consistent With the Common Defense and Security

    The proposed exemption excludes the MSIV pathway leakage 
contribution from the overall integrated leakage rate Type A test 
measurement and from the combined leakage rate of all penetrations 
and valves subject to Type B and Type C tests. This change to 
accounting for leakage rate measurement has no relation to security 
issues. Therefore, the exemption is consistent with the common 
defense and security.

D. Special Circumstances

    Under 10 CFR 50.12(a)(2)(ii) special circumstances include when, 
``[a]pplication 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 test requirements in Appendix J to 10 CFR part 50 ensure 
that leakage through containments or systems and components 
penetrating containments does not exceed allowable leakage rates 
specified in the technical specifications, and integrity of the 
containment structure is maintained during its service life. Option 
B of Appendix J identifies the performance-based requirements and 
criteria for preoperational and subsequent periodic leakage-rate 
testing.
    The licensee has analyzed the MS pathway leakage separately from 
the overall containment integrated leakage; the local leakage across 
pressure-containing or leakage-limiting boundaries; and the 
containment isolation valve leakage in its dose consequence 
analyses. The dose consequences were found to be within the 
applicable acceptance criteria in 10 CFR 50.67, ``Accident source 
term,'' and the guidance of NRC Regulatory Guide 1.183, 
``Alternative Radiological Source Terms for Evaluating Design Basis 
Accidents [DBAs] at Nuclear Power Reactors,'' dated July 2000 (ADAMS 
Accession No. ML003716792). The staff has reviewed the licensee's 
analysis and determined that the dose consequences of implementing 
the proposed change are below the applicable acceptance criteria and 
the containment leaks will continue to be limited by the QCNPS, 
Units 1 and 2, TSs.
    Therefore, because the underlying purposes of 10 CFR part 50, 
Appendix J, is still achieved, the special circumstances required by 
10 CFR 50.12(a)(2)(ii) for the granting of an exemption from 10 CFR 
part 50, Appendix J, Option B, Sections lII.A and III.B, exist.

E. Environmental Considerations

    The NRC staff determined that the issuance of the requested 
exemption meets the provisions of categorical exclusion 10 CFR 
51.22(c)(25) because: (i) No significant hazards consideration; (ii) 
no significant change in the types or significant increase in the 
amounts of any effluents that may be released offsite; (iii) no 
significant increase in individual or cumulative public or 
occupational radiation exposure; (iv) there is no significant 
construction impact; (v) there is no significant increase in the 
potential for or consequences from radiological accidents; and (vi) 
the requirements from which an exemption is sought involve e.g., 
inspection or surveillance requirements. Therefore, in accordance 
with 10 CFR 51.22(b), no environmental impact statement or 
environmental assessment need be prepared in connection with the 
NRC's issuance of this exemption. The basis for the NRC staff's 
determination is provided in the following evaluation of the 
requirements in 10 CFR 51.22(c)(25)(i)-(vi).

Requirements in 10 CFR 51.22(c)(25)(i)

    To qualify for a categorical exclusion under 10 CFR 
51.22(c)(25)(i), the exemption must involve ``no significant hazards 
consideration.'' The NRC staff evaluated whether the exemption 
involves no significant hazards consideration by using the standards 
in 10 CFR 50.92(c), as presented below:

    1. Does the requested exemption involve a significant increase 
in the probability or consequences of an accident previously 
evaluated?
    Response: No.
    The proposed exemption would permit exclusion of the MSIV 
pathway leakage contribution from the overall integrated leakage 
rate Type A test measurement and from the sum of the leakage rates 
from Type B and Type C tests. The leakage of primary containment 
atmosphere through MSIVs is accounted for as a separate contributor 
to the design basis LOCA dose consequence analysis. This exemption 
will allow the leakage testing to be performed in a manner 
consistent with the way MSIV leakage is modeled in the revised 
radiological consequence analysis included as part of the related 
license amendment requests (LARs) submitted in the letter dated 
March 5, 2019 as supplemented by the letters dated March 23, 2019, 
February 24, 2020, and March 31, 2020. This change to the leakage 
rate measurement does not increase the probability or consequences 
of an accident previously evaluated.
    Therefore, the exemption does not involve a significant increase 
in the probability or consequences of an accident previously 
evaluated.
    2. Does the requested exemption create the possibility of a new 
or different kind of accident from any accident previously 
evaluated?
    Response: No.
    The proposed exemption does not involve a physical modification 
to the plant (i.e., no new or different type of equipment will be 
installed and there are no physical modifications to existing 
equipment associated with the proposed change). Similarly, it does 
not physically change any structures, systems, or components 
involved in the mitigation of any accidents.
    Therefore, the exemption does not create the possibility of a 
new or different kind of accident from any accident previously 
evaluated.
    3. Does the requested exemption involve a significant reduction 
in a margin of safety?
    Response: No.

    The proposed exemption does not alter a design basis or safety 
limit nor cause a limit to be exceeded. The proposed exemption allows 
the results of the TS required MSIV leakage pathway tests to no longer 
be accounted for as part of the overall integrated leakage rate Type A 
test measurement and as part of the sum of the local leakage rates from 
Type B and Type C tests. This change only affects which leakage rates 
are included in the Types A, B, and C results. This exemption will 
allow the leakage testing to be performed in a manner consistent with 
the way MSIV leakage is modeled in the revised radiological consequence 
analysis submitted as part of the related LAR.
    Therefore, the exemption does not involve a significant reduction 
in a margin of safety.
    Based on the evaluation above, the NRC staff has determined that 
the proposed exemption involves no significant hazards consideration. 
Therefore, the requirements of 10 CFR 51.22(c)(25)(i) are met.
Requirements in 10 CFR 51.22(c)(9)(ii)
    To qualify for a categorical exclusion under 10 CFR 
51.22(c)(25)(ii), the exemption must result in ``no significant change 
in the types or significant increase in the amounts of any effluents 
that may be released offsite.'' The proposed exemption allows the 
results of the TS-required MSIV leakage pathway tests to be accounted 
for only as part of the design basis LOCA

[[Page 37968]]

consequence analysis. This change only affects the total in which the 
leakage rates are included and does not change the frequency or 
pressure at which the testing must be performed. The underlying purpose 
of 10 CFR part 50, Appendix J, is to demonstrate by periodic testing 
and visual inspection that the primary reactor containment will be able 
to perform its function of providing an essentially leak-tight barrier 
against uncontrolled release of radioactivity to the environment. The 
inclusion of the MSIV leakage testing results in the design basis LOCA 
serves the same purpose as the inclusion in the rate Type A test 
measurement and the sum of the leakage rates from Type B and Type C 
tests required by Appendix J, Option B, paragraphs III.A and III.B. 
Therefore, the proposed exemption will not significantly change the 
types of effluents that may be released offsite, or significantly 
increase the amount of effluents that may be released offsite. 
Therefore, the requirements of 10 CFR 51.22(c)(25)(ii) are met.
Requirements in 10 CFR 51.22(c)(9)(iii)
    To qualify for a categorical exclusion under 10 CFR 
51.22(c)(25)(iii), the exemption must result in ``no significant 
increase in individual or cumulative public or occupational radiation 
exposure.'' The proposed exemption permits the exclusion of the MSIV 
leakage pathway results from the Type A test measurement and the sum of 
the leakage rates from Type B and Type C tests required by Appendix J, 
Option B, paragraphs III.A and III.B, and has no impact on, or change 
to, fuel or core design. Additionally, the TSs still require that the 
MSIV leakage rates be tested and maintained below set limits. As such, 
the calculated public and occupational doses will remain essentially 
the same. Therefore, the proposed exemption will not significantly 
increase individual or cumulative public or occupational radiation 
exposure. Therefore, the requirements of 10 CFR 51.22(c)(25)(iii) are 
met.
Requirement in 10 CFR 51.22(c)(25)(iv)
    To qualify for a categorical exclusion under 10 CFR 
51.22(c)(25)(iv), the exemption must result in ``no significant 
construction impact.'' The exemption does not propose any changes to 
the site, alter the site, or change the operation of the site. 
Therefore, there is no significant construction impact. Therefore, the 
requirements of 10 CFR 51.22(c)(25)(iv) are met.
Requirement in 10 CFR 51.22(c)(25)(v)
    To qualify for a categorical exclusion under 10 CFR 
51.22(c)(25)(v), the exemption must involve ``no significant increase 
in the potential for or consequences from radiological accidents.'' The 
proposed exemption does not remove the requirement to perform leakage 
rate testing of the MSIVs. This exemption will allow the leakage 
testing to be performed in a manner consistent with the way MSIV 
leakage is modeled in the revised radiological consequence analysis 
submitted as part of the related LAR. Therefore, this change to the 
leakage rate measurement does not result in a significant increase in 
the potential for or consequences from radiological accidents. 
Therefore, the requirements of 10 CFR 51.22(c)(25)(v) are met.
Requirement in 10 CFR 51.22(c)(25)(vi)
    To qualify for a categorical exclusion under 10 CFR 
51.22(c)(25)(vi)(C), the exemption must involve inspection or 
surveillance requirements. The exemption seeks to permit exclusion of 
the MSIV leakage from the overall integrated leak rate Type A test 
measurement and the combined leakage rate of all penetrations and 
valves subject to Type B and Type C tests required by Appendix J to 10 
CFR part 50. Appendix J specifies the leakage rate test requirements, 
schedules, and acceptance criteria for tests of the leak-tight 
integrity of the reactor containment, and systems and components that 
penetrate the containment. Therefore, the exemption involves a 
surveillance requirement. Therefore, the requirements of 10 CFR 
51.22(c)(25)(vi) are met.
Conclusion
    Based on the above, the NRC staff concludes that the proposed 
exemption meets the eligibility criteria for the categorical exclusion 
set forth in 10 CFR 51.22(c)(25). Therefore, in accordance with 10 CFR 
51.22(b), no environmental impact statement or environmental assessment 
need be prepared in connection with the NRC's issuance of this 
exemption.

IV. Conclusions

    Accordingly, the NRC has determined that, pursuant to 10 CFR 50.12, 
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 
NRC hereby grants EGC a permanent exemption (1) from the requirements 
of 10 CFR part 50, Appendix J, Option B, Section III.A, to allow 
exclusion of the MSIV pathway leakage from the overall integrated 
leakage rate measured when performing a Type A test; and (2) from the 
requirements of 10 CFR part 50, Appendix J, Option B, Section III.B, to 
allow exclusion of the MSIV pathway leakage from the combined leakage 
rate of all penetrations and valves subject to Types B and C tests for 
QCNPS, Units 1 and 2.
    This exemption is effective upon issuance.

    Dated: 18th day of June 2020.

    For the Nuclear Regulatory Commission

Craig G. Erlanger,
Director, Division of Operating Reactor Licensing Office of Nuclear 
Reactor Regulation.

[FR Doc. 2020-13651 Filed 6-23-20; 8:45 am]
BILLING CODE 7590-01-P