Text

Transmittal of TSTF-538, Revision 0, Add Actions to Preclude Entry Into LCO 3.0.3 - RITSTF Initiatives 6b & 6c.
	ML12087A202
Person / Time
Site:	Technical Specifications Task Force
Issue date:	03/27/2012
From:	Browning R, Croft W, Steelman W, Stringfellow N; BWR Owners Group, PWR Owners Group
To:	; Office of Nuclear Reactor Regulation, Document Control Desk
References
	TSTF-12-06, Rev 0
	Download: ML12087A202 (47)
	v • d • e

TECHNICAL SPECIFICATIONS TASK FORCE TSTF A JOINT OWNERS GROUP ACTIVITY March 27, 2012 TSTF-12-06 PROJ0753 Attn: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Transmittal of TSTF-538, Revision 0, "Add Actions to Preclude Entry into LCO 3.0.3 - RITSTF Initiatives 6b & 6c" Enclosed for NRC review is Revision 0 of TSTF-538, "Add Actions to Preclude Entry into LCO 3.0.3 - RITSTF Initiatives 6b & 6c." TSTF-538 is applicable to Babcock & Wilcox plants.

We request that NRC review of the TSTF-538 be granted a fee waiver pursuant to the provisions of 10 CFR 170.11. Specifically, the request is to support NRC generic regulatory improvements (risk managed technical specifications), in accordance with 10 CFR 170.11(a)(1)(iii). This request is consistent with the NRC letter to A. R. Pietrangelo on this subject dated January 10, 2003 (ADAMS accession number ML030100090).

Should you have any questions, please do not hesitate to contact us.

Norman J. Stringfellow (PWROG/W) Roy A. Browning (BWROG)

William J. Steelman (PWROG/CE) Wendy E. Croft (PWROG/B&W)

Enclosure cc: Robert Elliott, Technical Specifications Branch, NRC Michelle Honcharik, Licensing Processes Branch, NRC 11921 Rockville Pike, Suite 100, Rockville, MD 20852 Phone: 301-984-4400, Fax: 301-984-7600 Administration by EXCEL Services Corporation

BWOG-119, Rev. 0 TSTF-538, Rev. 0 Technical Specifications Task Force Improved Standard Technical Specifications Change Traveler Add Actions to Preclude Entry into LCO 3.0.3 - RITSTF Initiatives 6b & 6c NUREGs Affected: 1430 1431 1432 1433 1434 Classification 1) Technical Change Recommended for CLIIP?: Yes Correction or Improvement: Improvement NRC Fee Status: Exemption Requested Benefit: Avoids a Plant Shutdown See attached.

Revision History OG Revision 0 Revision Status: Active Revision Proposed by: Areva Revision

Description:

Original Issue Owners Group Review Information Date Originated by OG: 07-Feb-12 Owners Group Comments (No Comments)

Owners Group Resolution: Approved Date: 22-Feb-12 TSTF Review Information TSTF Received Date: 22-Feb-12 Date Distributed for Review 22-Feb-12 OG Review Completed: BWOG WOG CEOG BWROG TSTF Comments:

(No Comments)

TSTF Resolution: Approved Date: 27-Mar-12 NRC Review Information NRC Received Date: 27-Mar-12 Affected Technical Specifications Action 3.6.6.B Containment Spray and Cooling Systems Change

Description:

Renamed C 27-Mar-12 Traveler Rev. 3. Copyright(C) 2012, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

BWOG-119, Rev. 0 TSTF-538, Rev. 0 Action 3.6.6.B Containment Spray and Cooling Systems Change

Description:

New Action Action 3.6.6.B Bases Containment Spray and Cooling Systems Change

Description:

New Action Action 3.6.6.B Bases Containment Spray and Cooling Systems Change

Description:

Renamed C Action 3.6.6.C Containment Spray and Cooling Systems Change

Description:

Renamed D Action 3.6.6.C Bases Containment Spray and Cooling Systems Change

Description:

Renamed D Action 3.6.6.D Containment Spray and Cooling Systems Change

Description:

Renamed E Action 3.6.6.D Bases Containment Spray and Cooling Systems Change

Description:

Renamed E Action 3.6.6.E Containment Spray and Cooling Systems Change

Description:

Renamed G Action 3.6.6.E Bases Containment Spray and Cooling Systems Change

Description:

Renamed G Action 3.6.6.F Containment Spray and Cooling Systems Change

Description:

Renamed G Action 3.6.6.F Bases Containment Spray and Cooling Systems Change

Description:

Renamed G Action 3.6.6.G Containment Spray and Cooling Systems Change

Description:

Renamed H Action 3.6.6.G Bases Containment Spray and Cooling Systems Change

Description:

Renamed H Action 3.7.10.D CREVS Change

Description:

Renamed F Action 3.7.10.D CREVS Change

Description:

New Action Action 3.7.10.D Bases CREVS Change

Description:

New Action Action 3.7.10.D Bases CREVS Change

Description:

Renamed F Action 3.7.10.E CREVS Change

Description:

Renamed G 27-Mar-12 Traveler Rev. 3. Copyright(C) 2012, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

BWOG-119, Rev. 0 TSTF-538, Rev. 0 Action 3.7.10.E CREVS Change

Description:

New Action Action 3.7.10.E Bases CREVS Change

Description:

New Action Action 3.7.10.E Bases CREVS Change

Description:

Renamed G Action 3.7.10.F CREVS Change

Description:

Deleted Action 3.7.10.F Bases CREVS Change

Description:

Deleted Bkgnd 3.7.12 Bases EVS S/A 3.7.12 Bases EVS LCO 3.7.12 Bases EVS Action 3.7.12.C EVS Change

Description:

New Action Action 3.7.12.C EVS Change

Description:

Renamed D Action 3.7.12.C Bases EVS Change

Description:

Renamed D Action 3.7.12.D EVS Change

Description:

Renamed E Action 3.7.12.D Bases EVS Change

Description:

Renamed E 27-Mar-12 Traveler Rev. 3. Copyright(C) 2012, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

TSTF-538, Rev. 0 1.0 Summary Description The proposed change provides risk-informed Technical Specifications (TS) modifications which will improve plant safety by precluding certain unnecessary, exigent plant shutdowns. It revises the current Required Actions of two Technical Specifications when both system trains are inoperable from a Limited Condition for Operation (LCO) 3.0.3 entry to an action to restore inoperable systems with a Completion Time (CT) of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

The three TS modified by the proposed change are:

3.6.6, Containment Spray and Cooling Systems;

3.7.10, Control Room Emergency Ventilation System (CREVS); and

3.7.12, Emergency Ventilation System (EVS).

To support the proposed change, a conservative analysis was performed using the Alternative Source Term (AST) methodology that is intended to bound any differences that may exist between the Babcock & Wilcox (B&W) designed plants for which these changes are intended. At present, all B&W designed plants have implemented the AST except for Davis-Besse. During adoption of the AST, the licensees relocated the Emergency Ventilation System Technical Specification. Therefore, a plant-specific evaluation using the classical (TID) methodology has been performed for Davis-Besse that addresses the use of the EVS. These measures ensure the proposed change is applicable to all Babcock & Wilcox designed plants.

2.0 Detailed Description In response to the Nuclear Regulatory Commission (NRC) initiative to improve plant safety by developing risk-informed TS, the industry has undertaken a program for defining and obtaining risk-informed TS modifications. This proposed change will modify the Required Actions applicable when both trains of Containment Spray or both trains of CREVs are inoperable to extend the time required to initiate a plant shutdown from 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months in accordance with LCO 3.0.3 to a risk-informed Completion Time of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

This Traveler revises the following Specifications in NUREG-1430 to preclude immediate entry into LCO 3.0.3 under some circumstances:

1. TS 3.6.6, "Containment Spray and Cooling Systems," for the condition of two containment spray trains inoperable;

2. TS 3.7.10, "Control Room Emergency Ventilation System (CREVS)," for the condition of two CREVS trains inoperable in Modes 1, 2, 3, and 4, for reasons other than an inoperable control room boundary; and

3. TS 3.7.12, "Emergency Ventilation System (EVS)," for the condition of two EVS trains inoperable in Modes 1, 2, 3, and 4, for reasons other than an inoperable auxiliary building negative pressure area boundary. Note that all B&W plants 1

TSTF-538, Rev. 0 have relocated the EVS specification except for Davis-Besse. The proposed change will revise NUREG-1430 and provides plant-specific justification for Davis-Besse adoption of the proposed change to TS 3.7.12.

The Bases are modified to reflect the changes to the Specifications. As Davis-Besse is the only B&W plant which has an EVS specification, the Bases are revised to be consistent with the Davis-Besse design and the analysis of the proposed change. contains the proposed model application for plant-specific adoption of the change.

3.0 Technical Evaluation The Containment Spray System and the Control Room Emergency Ventilation System are designed to mitigate either off-site or on-site dose following a design basis accident with successful containment isolation. As such, these systems are designed to ensure that the following requirements are met:

For Plants without AST implementation

10 CFR 100.11 - An individual located at any point on the boundary of the exclusion area for two hours immediately following onset of the postulated fission product release will not receive a total radiation dose to the whole body in excess of 25 rem or a total radiation dose in excess of 300 rem to the thyroid from iodine exposure.

An individual located at any point on the outer boundary of the low population zone who is exposed to the radioactive cloud resulting from the postulated fission product release (during the entire period of its passage) will not receive a total radiation dose to the whole body in excess of 25 rem or a total radiation dose in excess of 300 rem to the thyroid from iodine exposure.

10 CF 50, Appendix A, General Design Criteria (GDC) Adequate radiation protection shall be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of 5 rem whole body, or its equivalent to any part of the body, for the duration of the accident.

For Plants with AST Implementation

An individual located at any point on the boundary of the exclusion area for any 2-hour period following the onset of the postulated fission product release, will not receive a radiation dose in excess of 0.25 Sv (25 rem) total effective dose equivalent (TEDE).

An individual located at any point on the outer boundary of the low population zone, who is exposed to the radioactive cloud resulting from the postulated fission product release (during the entire period of its passage), will not receive a radiation dose in excess of 0.25 Sv (25 rem) total effective dose equivalent (TEDE).

Adequate radiation protection is provided to permit access to and occupancy of the control room under accident conditions without personnel receiving radiation 2

TSTF-538, Rev. 0 exposures in excess of 0.05 Sv (5 rem) total effective dose equivalent (TEDE) for the duration of the accident.

Regulatory Guide 1.174 (RG 1.174) and Regulatory Guide 1.177 (RG 1.177) are used to provide an evaluation of risk presented by modifying the Completion Time of Required Actions applicable when both trains of these systems are inoperable. Both RG 1.174 and RG 1.177 provide risk goals based on the increase in frequency of large early release events (LERF) for plant modifications and Technical Specification changes.

Regulatory Guide 1.174 RG 1.174 provides an approach for using Probabilistic Risk Assessment for risk-informed decisions on plant specific changes to existing licensing basis. RG 1.174 is intended to provide a general approach to risk-informed decision making and addresses specific topics common to all risk-informed regulatory applications. RG 1.174 provides the following guideline for the impact of LERF:

"When the calculated increase in LERF is very small, which is taken as being less than 10-7 per reactor year, the change will be considered regardless of whether there is a calculation of the total LERF."

Regulatory Guide 1.177 RG 1.177 provides guidance specifically for risk-informed assessment of the impact of TS changes to Completion Times and Surveillance Test Intervals (STIs). In addition to meeting the provided risk metrics, RG 1.177 highlights the need to ensure traditional engineering goals are still maintained. These traditional engineering goals include:

Defense in Depth - The proposed TS change must be consistent with traditional defense in depth philosophy. In this regard, the intent is to maintain the defense in depth, and not to prevent changes to the way in which the defense in depth is maintained.

Safety Margins - The proposed TS change must ensure that sufficient safety margins are maintained. This includes maintaining codes and standards and FSAR acceptance criteria. If safety margins are impacted, justification must be provided to ensure sufficient safety margin will continue to exist.

RG 1.177 directs that the resulting quantitative results for CDF and LERF be incorporated within a three-tiered assessment. The three tiers are as follows:

Tier 1: Access the impact of the proposed TS change on plant CDF and LERF.

Tier 2: Ensure that risk-significant equipment outage configurations will not result additional plant equipment being out of service simultaneously with the TS implementation

Tier 3: Develop a program for evaluating the risk impact of out of service equipment simultaneous with the TS equipment out of service. Tier 3 shall augment Tier 2, since all possible risk significant configurations may not be identified in Tier 2.

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TSTF-538, Rev. 0 3.1 Risk Assessment Risk of an event is characterized by the combination of the frequency of the event in combination with the resulting consequences of that event. Because the systems evaluated are designed to mitigate radioactive dose, either onsite or offsite, their risk was evaluated based on the LERF guidelines. The objective of the analyses was to show that:

The consequences resulting from these systems being unavailable during an accident will be well below that experienced by an LER.

The frequency of an event occurring simultaneously with the system unavailable (assuming the extended Completion Time) will be comparable to the guidelines presented for LER events.

Therefore, by meeting the above objectives, it can be shown that the proposed Completion Time modifications will be acceptable based on the guidelines presented in R.G 1.174 and RG 1.177.

3.1.1 Characterization of Risk Risk is defined by the combination of estimated frequency and estimated consequences.

It should be noted that a plant transition from power operation (Mode 1) to cold shutdown (Mode 5), in itself, results in some small additional increase in plant risk. To evaluate the risk presented by the proposed change, both the frequency of events challenging these systems and the expected radiological consequences need to be determined. The guidelines presented in RGs 1.174 and 1.177 will be utilized to provide a basis for estimating the potential risk posed by these Completion Time modifications.

To assess the resulting risk of the proposed TS modifications, the following steps have been performed.

The incremental frequency was estimated for a plant event challenging the system in question, simultaneous with that system being inoperable during the period allowed by the proposed Completion Time, and

Radiological calculations were performed to evaluate the dose results, with these systems either being Operable to mitigate a Large Early Release, or inoperable for DBAs that rely on these systems for dose-consequence mitigation.

3.2 Radiological Assessment 3.2.1 Systems of Interest and Accident Scenarios The systems of interest are for the control of radioactivity releases, and include the following:

(a) Containment Spray System (CSS),

(b) Control Room Emergency Ventilation System (CREVS), and (c) Station Emergency Ventilation System (EVS) (non-ISTS).

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TSTF-538, Rev. 0 The CSS and CREVS are of interest for all the B&W plants, while the EVS (which is credited for the filtration of containment leakage) is applicable only to Davis-Besse.

To assess the impact of the proposed change on the various systems, radiological calculations were performed for scenarios in which the systems are both available and unavailable. To evaluate these systems, two accident scenarios were considered in the radiological analyses, as follows:

A Large Early Release (LER), and

A Maximum Hypothetical Accident (MHA).

LER (Large Early Release)

An LER is defined as an event resulting in release fractions to the environment of the volatile/semi-volatile fission products (iodine, cesium, tellurium) equal to or greater than about 2.5% to 3% of the entire core as a result of severe core melt and failed containment (un-isolatable or bypassed). Such a release, with a release duration of about 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , will give rise to one mean early fatality within 1 mile of the plant boundary.

MHA (Maximum Hypothetical Accident)

The MHA is a design basis event at a nuclear power plant characterized by partial fuel melt, with significant release of volatile/semi-volatile fission products from the fuel matrix to the containment. Unlike the LER, however, the containment remains intact (though leaking at a TS limit), and significant dose reduction can be achieved as a result of holdup of the radionuclides therein. In addition, release filtration and/or containment sprays provide significant reduction of airborne radioactivity, when Operable.

The release pathway of interest is the direct release of airborne radioactivity from the primary containment to the atmosphere, with or without filtration, as applicable. Other concurrent release pathways, such as post-LOCA ESF-component leakage of contaminated fluids to the Auxiliary Building, and back-leakage to the Refueling Water Storage Tanks, are of no interest since they have minimal impact on the radiological consequences of an LER (in which failure of the primary containment is postulated).

Similarly, other LOCA scenarios (such as an LBLOCA and an SBLOCA) are also of no interest for two reasons:

Their radiological consequences are bounded by the MHA, and

Their scenario differences from the MHA have no impact on the LER since the latter is based on a pre-defined release of activity to the atmosphere.

With respect to the radiological assessment models, use was made of both of the following:

The classical (TID) methodology (based on RG 1.195, and applicable only to Davis-Besse), and 5

TSTF-538, Rev. 0

The Alternative Source Term (AST) methodology (based on RG 1.183, and applicable to all B&W plants except Davis-Besse).

3.2.2 Acceptance Criteria The acceptance criteria for the Completion Time modifications consist of a combination of the frequency of occurrence of a plant event and the ensuing potential radiological consequences. Specifically, the following must be demonstrated:

(a) The incremental frequency of occurrence of the plant event challenging the system in question is approximately of the same magnitude as a "very small" change in the plant LERF (i.e., an incremental frequency of 1.0E-07 per reactor-yr, as described in Section 3.0), and (b) The ensuing radiological consequences of the analyzed MHA without the mitigating effects of an inoperable system are significantly lower than those for an LER with full credit for the mitigating effects of the system being evaluated.

Acceptance criterion (b) implies that a comparison needs to be carried out between of the radiological consequences of an MHA and the corresponding consequences of an LER.

However, the same conclusion can be arrived at by simply comparing the atmospheric releases of a prominent radionuclide without the need of dose computations at receptors of interest. This has the advantage of eliminating the need to specify the exposure-pathway variables (namely, atmospheric dispersion factors, breathing rates, occupancy factors and dose conversion factors). The analyses summarized in the present document were based on the post-accident atmospheric releases of I-131, a significant contributor to the dose.

The I-131 release ratio, as described, is directly applicable to the Completion Time evaluation for the Containment Spray System (CSS) and the Davis-Besse Emergency Ventilation System (EVS). To extend the model to the Control Room Emergency Ventilation System (CREVS), it was necessary to make an additional modeling simplification. Specifically, the LER atmospheric releases calculated for the CSS and EVS Completion Time evaluations were subjected to an adjustment factor that would make the releases suitable for evaluation of the CREVS Completion Time. This adjustment factor was selected to be equal to the maximum Iodine Protection Factor (IPF) that the CREVS would provide (i.e., that under equilibrium conditions). Thus, if an LER to the atmosphere is divided by the maximized IPF, and the result is higher than the MHA atmospheric release with all systems operable, the Completion Time for CREVS based on this result would be acceptable.

3.2.3 Design Input The following design inputs are noted:

(a) The analyses involve the use of both TID and AST methodologies. Because of the large fraction of organic iodines in the TID model (4% vs. 0.15% for the AST), and because this iodine species is not reduced by the Containment Spray System, the acceptance criterion for the proposed 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months CSS Completion Time for plants licensed under the TID methodology cannot be met unless some other 6

TSTF-538, Rev. 0 system can be credited for mitigating the atmospheric releases. Consequently, two sets of variables are presented for the radiological evaluations, as follows:

For generic analyses applicable to all plants that have implemented the AST methodology, with CSS as the only system for mitigation of the atmospheric releases, when Operable, and

For a plant-specific analysis, applicable to Davis-Besse (TID methodology) and the potential for atmospheric release mitigation by the CSS and/or EVS, as applicable.

(b) The power level employed in the generic analysis (3000 MWt) has no impact on the final results since the acceptance criterion is based on comparative analyses between the LER and MHA releases.

(c) As noted above, the LER is defined as a containment failure leading to the release of 2.5% to 3.5% of the core inventory within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . As a conservative measure (to minimize the LER/MHA release ratio), use was made of the lower core-release fraction, i.e., 2.5%. In addition, for sensitivity evaluations, two LER scenarios were analyzed:

LER-1, where the 2.5% core-inventory release is attained within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months (as defined), and

LER-2, where the release is attained in half the time (2 hrs).

(d) Since it was not clear a priori whether high or low containment spray effects would be conservative, use was made of two sets of spray removal constants in the generic LER analyses, for sensitivity analyses.

Typical values, selected to bound the B&W plants, and

Conservative values.

For the Davis-Besse case, only the site-specific spray removal constants were used.

3.3 Results 3.3.1 Frequency of Occurrence The incremental frequency, FREQEvent, for the occurrence of a plant event simultaneous with two trains inoperable is defined as:

FREQEvent = FREQEvent

t / T (Eq. 2.1) where FREQEvent = frequency of plant event t = length of Completion Time (hrs) 7

TSTF-538, Rev. 0 T = time interval (hrs) during which the Completion Time will be entered once.

The scenario that provides the most significant challenge to the CSS, EVS and CREVS is the MHA. There has been one occurrence of an MHA in the US plant operating history.

Based on Reference 2, there have been 3,567 reactor years of operation during the years 1973 through 2011. Based on this conservative data point (which excludes the operating years prior to 1973, as well as the operating times since 2010), the frequency of an MHA is estimated to be:

FREQMHA = 1 / 3,567 (reactor-yrs) = 2.8E-4 per reactor-yr Given the improvements in plant design arising from post-TMI activities (such as the Individual Plant Examination process and more sophisticated accident management capabilities), it is likely that this value is high and that a Bayesian update would improve it. However, based on this conservative estimate of MHA frequency, the incremental challenge frequency defined by the above equation is summarized in Table 3-1 for various combinations of t and T.

Table 3-1: Incremental Challenge Frequency for an MHA (FREQMHA)

Interval during which Incremental Challenge (FREQMHA) per Required Action will be T vs. Completion Time Duration t Entered T' (years) T (hrs) t =24 hr t =48 hr t =72 hr 1 8760 7.7E-07 1.5E-06 2.3E-06 2 17520 3.8E-07 7.7E-07 1.2E-06 3 26280 2.6E-07 5.1E-07 7.7E-07 t and T values suitable for the present application were selected to be as follows:

CSS: 24-hr Completion Time assumed to be entered once every 3 years (FREQMHA = 2.6E-07)

EVS: 24-hr Completion Time assumed to be entered once every 3 years (FREQMHA = 2.6E-07)

CREVS: 24-hr Completion Time assumed to be entered once every 3 years (FREQMHA = 2.6E-07) 3.3.2 Radiological Consequences Tables 3-2 and 3-3 summarize the results of the radiological evaluations performed. The results are presented as ratios of LER release versus MHA release with the system in question unavailable. Included in the tabulations are the sensitivity evaluations for two LER cases, as well as for two sets of spray removal constants for the generic LER analyses (as described in Section 3.2.3).

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TSTF-538, Rev. 0 Table 3-2: I-131 Release Ratios for Generic Completion Time Evaluations I-131 Release Ratios Description Conservative Spray Typical Spray Removal Constants Removal Constants Containment Spray System (CSS)

LER-1/MHA without 9.9 7.4 CSS LER-2/MHA without 5.6 5.0 CSS Control Room Emergency Ventilation System (CREVS)

LER-1/MHA with CSS 4.3 5.4 LER-2/MHA with CSS 2.5 3.6 Table 3-3: I-131 Release Ratios for Davis Besse Completion Time Evaluations I-131 Release Description Ratios Containment Spray System (CSS)

LER-1/MHA with EVS but w/o 102 CSS LER-2/MHA with EVS but w/o 67 CSS Station Emergency Ventilation System (EVS)

LER-1/MHA with CSS but w/o 75 EVS LER-2/MHA with CSS but w/o 49 EVS Control Room Emergency Ventilation System (CREVS)

LER-1/MHA with CSS and EVS 6.6 LER-2/MHA with CSS and EVS 4.4 Note, LER/MHA release ratios are equivalent to the LER/MHA dose-consequence ratios.

3.4 Summary and Conclusions 3.4.1 Frequency of Occurrence Section 3.3.1 presents a description of incremental challenge frequency for an MHA (FREQMHA), along with a tabulation of its values for various combinations of t (the length of Completion Time) and T (the time interval during which the Completion Time will be used once). As described in that section, the selected t and T values for the 9

TSTF-538, Rev. 0 various systems analyzed, and the corresponding frequencies for an MHA simultaneous with two system trains inoperable at the same time are as follows:

CSS: 24-hr Completion Time assumed to be entered once every 3 years (FREQMHA = 2.6E-07)

EVS: 24-hr Completion Time assumed to be entered once every 3 year (FREQMHA = 2.6E-07)

CREVS: 24-hr Completion Time assumed to be entered once every 3 years (FREQMHA = 2.6E-07) 3.4.2 Radiological Evaluation The radiological results are summarized in Table 3-4 (based on the minimum LER/MHA ratios in Tables 3-2 and 3-3). It is seen that in all cases the LER radiological impact bounds the corresponding impact of an MHA with both trains of any given system inoperable at the same time.

Table 3-4: Summary of (LER/MHA) Dose Consequence Ratios Minimum Dose Consequence Ratio Description (LER/MHA)

Evaluation Generic Plant-Specific Radiological Evaluation AST TID Methodology Arkansas 1 Crystal River 3 Power Plant Davis-Besse Oconee 1,2,3 Three Mile Island 1 CSS 5.0 67 System EVS N/A 49 CREVS 2.5 4.4 Note that the maximum EVS benefit is a factor of 20 reduction in the iodine release (for an exhaust filtration efficiency of 95%). Thus, for the EVS being out of service in addition to the CSS, the minimum dose consequence ratio would still be in excess of unity [or (67/20) = 3.35] for Davis-Besse. This observation provides additional justification for the 24-hour Completion Time proposed for the EVS.

In summary, based on the fact that the expected MHA doses with the noted systems being unavailable during the extended Completion Times are well below those of an LER event, and that the estimated frequencies are similar to the guideline value used for LER events, it is judged that that the recommended Completion Times, as given above, for inoperability of both trains of any given system, are acceptable based on a risk perspective.

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TSTF-538, Rev. 0 3.5 Additional Discussion of the Proposed Technical Specification Changes 3.5.1 Containment Spray System Current Technical Specification Requirement If two trains of containment spray are inoperable, enter LCO 3.0.3 immediately.

Licensing Basis The design basis analysis assumes the worst case single failure as the loss of one ESF bus, resulting in one train of containment spray and one train of containment cooling being inoperable. For the design basis accident (Large Break Loss of Coolant Accident, LBLOCA), one Operable containment spray train and one Operable containment cooling train maintain the resulting containment pressure and temperature to within design limits.

Defense-in-Depth Consideration Inoperability of the containment spray systems will degrade the ability of the plant personnel to control containment temperature and pressure following various transients and accidents that release primary or secondary system energy to containment. The containment spray system is not credited for reducing iodine releases.

The containment air coolers are designed such that they alone can maintain containment temperature and pressure within design limits. To ensure adequate defense in depth, all trains of the containment air coolers must be Operable when both trains of CS are inoperable. This provision is implemented by the existing Technical Specification Condition which requires immediate entry into LCO 3.0.3 should any combination of three or more trains become inoperable.

Tier 2 Recommendations Ensure that all trains of containment air coolers are Operable when both trains of containment spray are inoperable. This provision is implemented by the existing Technical Specification Condition which requires immediate entry into LCO 3.0.3 should any combination of three or more trains become inoperable. In addition, the CREVS should be verified to be Operable within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months to provide additional protection to the control room staff from released radioactive material.

Tier 3 Recommendations Tier 3 is implemented by the licensee implementation of 10 CFR 50.65, the Maintenance Rule.

3.5.2 Control Room Emergency Ventilation Current Technical Specification Requirement If two trains of CREVS are inoperable for reasons other than an inoperable control room boundary, enter LCO 3.03. immediately.

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TSTF-538, Rev. 0 Licensing Basis The CREVS provides a protected environment from which operators can control the unit following an uncontrolled release of radioactivity, hazardous chemicals, or smoke.

Defense-in-Depth Consideration Should both trains of CREVS be inoperable, immediate action must be taken to implement mitigating actions. These mitigating actions are the same as those required by existing Required Action B.1. Action B.1 was added by TSTF-448-A, Revision 3, "Control Room Habitability," which was approved by the NRC on January 17, 2007.

The Technical Specification Bases of Condition B and of SR 3.7.10.4 describe acceptable mitigating actions. Licensees desiring to adopt the proposed change to TS 3.7.11 that have not adopted TSTF-448-A must implement mitigating actions equivalent to those described in TSTF-448-A.

Tier 2 Recommendations Immediately implement mitigating actions to protect the control room occupants.

Tier 3 Recommendations Tier 3 is implemented by the licensee implementation of 10 CFR 50.65, the Maintenance Rule.

3.5.3 Emergency Ventilation System Limiting Condition for Operation If two trains of EVS are inoperable for reasons other than an inoperable auxiliary building negative pressure area boundary, enter LCO 3.03. immediately.

Licensing Basis for Operation The EVS collects post-accident primary-containment leakage to the shield building and filters it prior to releases to the atmosphere. Total system failure could result in atmospheric release from the negative pressure area boundary exceeding 10 CFR 100.11 limits in the event of a Design Basis Accident.

Defense-in-Depth Consideration The EVS limits the radioactive release to the atmosphere by filtering primary containment leakage. With both trains of EVS unavailable, releases may be reduced by a train of CSS.

Tier 2 Recommendations A train of CSS should be verified to be Operable within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months to reduce releases from the containment.

Tier 3 Recommendations Tier 3 is implemented by the licensee implementation of 10 CFR 50.65, the Maintenance Rule.

12

TSTF-538, Rev. 0 4.0 Regulatory Evaluation 4.1 Applicable Regulatory Requirements/Criteria General guidance for evaluating the technical basis for proposed risk-informed changes is provided in Section 19.2, "Review of Risk Information Used to Support Permanent Plant-Specific Changes to the Licensing Basis: General Guidance," of the NRC Standard Review Plan (SRP), NUREG-0800. More specific guidance related to risk-informed TS changes, including changes to TS CTs, is provided in SRP Section 16.1, "Risk-Informed Decisionmaking: Technical Specifications." The proposed change is consistent with the acceptance criteria in the SRP for risk-informed changes.

10 CFR 50.36 provides the requirement for all licenses to contain Technical Specifications. 10 CFR 50.36(c)(2) states that when a limiting condition for operation is not met, the licensee shall shut down the plant or follow any remedial action permitted by the technical specifications until the condition can be met. Thus, the regulatory requirements are not specific regarding the actions to be followed when Technical Specification requirements are not met. The proposed change to the Technical Specification Actions does not affect regulatory requirements.

In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the approval of the proposed change will not be inimical to the common defense and security or to the health and safety of the public.

4.2 No Significant Hazards Consideration Determination The TSTF has evaluated whether or not a significant hazards consideration is involved with the proposed generic change by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change provides a short Completion Time to restore an inoperable system for conditions under which the existing Technical Specifications require a plant shutdown to begin within one hour in accordance with Limiting Condition for Operation (LCO) 3.0.3. Entering into Technical Specification Actions is not an initiator of any accident previously evaluated. As a result, the probability of an accident previously evaluated is not significantly increased. The consequences of any accident previously evaluated that may occur during the proposed Completion Times are no different from the consequences of the same accident during the existing one hour allowance. As a result, the consequences of any accident previously evaluated are not significantly increased.

13

TSTF-538, Rev. 0 Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

No new or different accidents result from utilizing the proposed change. The changes do not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. In addition, the changes do not impose any new or different requirements.

The changes do not alter assumptions made in the safety analysis.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed change provides a short Completion Time to restore an inoperable system for conditions under which the existing Technical Specifications require a plant shutdown to begin within one hour in accordance with LCO 3.0.3. The justification demonstrates that there is an acceptably small increase in risk due to a limited period of continued operation in these conditions and that this risk is balanced by avoiding the risks associated with a plant shutdown. As a result, the change to the margin of safety provided by requiring a plant shutdown within one hour is not significant.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, the TSTF concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

5.0 Environmental Consideration A review has determined that the proposed change would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement.

However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, 14

TSTF-538, Rev. 0 pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed change.

6.0 References

1. U.S. AEC (now NRC) Document TID-14844, "Calculation of Distance Factors for Power and Test Reactor Sites" (Mar. 1962).

2. U.S Energy Information Administration, November 2010 Monthly Energy Review.

15

TSTF-538, Rev. 0 Attachment 1 Model Application for Adoption

TSTF-538, Rev. 0

[DATE] 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 PLANT NAME DOCKET NO. 50-[xxx]

SUBJECT:

APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT TSTF-538, "ADD ACTIONS TO PRECLUDE ENTRY INTO LCO 3.0.3 - RITSTF INITIATIVES 6B & 6C," USING THE CONSOLIDATED LINE ITEM IMPROVEMENT PROCESS Pursuant to 10 CFR 50.90, [LICENSEE] is submitting a request for an amendment to the Technical Specifications (TS) for [PLANT NAME, UNIT NOS.].

The proposed amendment would modify TS requirements to adopt the changes described in TSTF-538, Revision 0, "Add Actions to Preclude Entry into LCO 3.0.3 - RITSTF Initiatives 6b

& 6c." provides a description and assessment of the proposed changes, the requested confirmation of applicability, and plant-specific verifications. Attachment 2 provides the existing TS pages marked up to show the proposed changes. Attachment 3 provides revised (clean) TS pages. Attachment 4 provides existing TS Bases pages marked up to show the proposed changes.

Approval of the proposed amendment is requested by [date]. Once approved, the amendment shall be implemented within [ ] days.

In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated [STATE] Official.

[In accordance with 10 CFR 50.30(b), a license amendment request must be executed in a signed original under oath or affirmation. This can be accomplished by attaching a notarized affidavit confirming the signature authority of the signatory, or by including the following statement in the cover letter: "I declare under penalty of perjury that the foregoing is true and correct.

Executed on (date)." The alternative statement is pursuant to 28 USC 1746. It does not require notarization.]

Page 1

TSTF-538, Rev. 0 If you should have any questions regarding this submittal, please contact [NAME, TELEPHONE NUMBER].

Sincerely,

[Name, Title]

Attachments: 1. Description and Assessment

2. Proposed Technical Specification Changes (Mark-Up)

3. Revised Technical Specification Pages

4. Proposed Technical Specification Bases Changes (Mark-Up) cc: NRC Project Manager NRC Regional Office NRC Resident Inspector State Contact Page 2

TSTF-538, Rev. 0 ATTACHMENT 1 - DESCRIPTION AND ASSESSMENT

1.0 DESCRIPTION

The proposed change provides a short Completion Time to restore an inoperable system for conditions under which the existing Technical Specifications require a plant shutdown. The proposed amendment is consistent with TSTF-538, Revision 0, " Add Actions to Preclude Entry into LCO 3.0.3 - RITSTF Initiatives 6b & 6c."

2.0 ASSESSMENT 2.1 Applicability of Published Safety Evaluation

[LICENSEE] has reviewed the model safety evaluation dated [DATE] as part of the Federal Register Notice of Availability. This review included a review of the Nuclear Regulatory Commission (NRC) staff evaluation, as well as the information provided in TSTF-538, Revision 0. [As described in the subsequent paragraphs, ][LICENSEE] has concluded that the justifications presented in the TSTF-538 proposal and the model safety evaluation prepared by the NRC staff are applicable to [PLANT, UNIT NOS.] and justify this amendment for the incorporation of the changes to the [PLANT] Technical Specifications.

2.2 Optional Changes and Variations

[LICENSEE is not proposing any variations or deviations from the Technical Specifications changes described in the TSTF-538, Revision 0, or the applicable parts of the NRC staffs model safety evaluation dated [DATE].] [LICENSEE is proposing the following variations from the Technical Specifications changes described in the TSTF-538, Revision 0, or the applicable parts of the NRC staffs model safety evaluation dated [DATE].]

[The [PLANT] Technical Specifications do not include an [Emergency Ventilation System.]

Therefore the TSTF-538 changes for that system are not included.]

[The [PLANT] Technical Specifications utilize different [numbering][and][titles] than the Standard Technical Specifications on which TSTF-538 was based. Specifically, [describe differences between the plant-specific Technical Specifications numbering and/or titles and the TSTF-538 numbering and titles.] These differences are administrative and do not affect the applicability of TSTF-538 to the [PLANT] Technical Specifications.]

2.3 Licensee Verifications

((LICENSEE] confirms that plant procedures can establish temporary alternate means of control room cooling, as assumed in the justification of the proposed change to the Control Room Emergency Ventilation System.]

[The [PLANT] Technical Specifications are not based on the NUREG-1430, "Standard Technical Specifications, Babcock & Wilcox Plants." [LICENSEE] [confirms] [proposes to modify] the Containment Spray and Cooling Technical Specification [to] contain Page 3

TSTF-538, Rev. 0 requirements equivalent to NUREG-1430 with regard to simultaneous inoperability of three trains of containment spray and containment cooling.]

3.0 REGULATORY ANALYSIS

3.1 No Significant Hazards Consideration Determination

[LICENSEE] requests adoption of TSTF-538, Revision 0, "Add Actions to Preclude Entry into LCO 3.0.3 - RITSTF Initiatives 6b & 6c," which is an approved change to the standard technical specifications (STS), into the [PLANT NAME, UNIT NOS] Technical Specifications. The proposed change provides a short Completion Time to restore an inoperable system for conditions under which the existing Technical Specifications require a plant shutdown to begin within one hour in accordance with Limiting Condition for Operation (LCO) 3.0.3.

[LICENSEE] has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change provides a short Completion Time to restore an inoperable system for conditions under which the existing Technical Specifications require a plant shutdown to begin within one hour in accordance with Limiting Condition for Operation (LCO) 3.0.3. Entering into Technical Specification Actions is not an initiator of any accident previously evaluated. As a result, the probability of an accident previously evaluated is not significantly increased. The consequences of any accident previously evaluated that may occur during the proposed Completion Times are no different from the consequences of the same accident during the existing one hour allowance. As a result, the consequences of any accident previously evaluated are not significantly increased.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

No new or different accidents result from utilizing the proposed change. The changes do not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. In addition, the changes do not impose any new or different requirements. The changes do not alter assumptions made in the safety analysis.

Page 4

TSTF-538, Rev. 0 Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed change provides a short Completion Time to restore an inoperable system for conditions under which the existing Technical Specifications require a plant shutdown to begin within one hour in accordance with LCO 3.0.3. The justification demonstrates that there is an acceptably small increase in risk due to a limited period of continued operation in these conditions and that this risk is balanced by avoiding the risks associated with a plant shutdown. As a result, the change to the margin of safety provided by requiring a plant shutdown within one hour is not significant.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, [LICENSEE] concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

4.0 ENVIRONMENTAL EVALUATION The proposed change would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed change.

Page 5

TSTF-538, Rev. 0 Containment Spray and Cooling Systems 3.6.6 3.6 CONTAINMENT SYSTEMS 3.6.6 Containment Spray and Cooling Systems LCO 3.6.6 Two containment spray trains and two containment cooling trains shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One containment spray A.1 Restore containment spray [7] days train inoperable. train to OPERABLE status.

B. ------------ NOTE ----------- B.1 Verify LCO 3.7.10, 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Not applicable when "CREVS," is met.

second containment spray train intentionally AND made inoperable.

B.2 Restore at least one 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months containment spray train to Two containment spray OPERABLE status.

trains inoperable.

CB. Required Action and CB.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time of Condition A or B AND not met.

CB.2 --------------NOTE---------------

LCO 3.0.4.a is not applicable when entering MODE 4.

Be in MODE 4. 60 hours6.944444e-4 days 0.0167 hours 9.920635e-5 weeks 2.283e-5 months DC. One [required] DC.1 Restore [required] 7 days containment cooling containment cooling train to train inoperable. OPERABLE status.

Babcock & Wilcox STS 3.6.6-1 Rev. 4.0

TSTF-538, Rev. 0 Containment Spray and Cooling Systems 3.6.6 ED. One containment spray ED.1 Restore containment spray 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months train and one [required] train to OPERABLE status.

containment cooling train inoperable. OR ED.2 Restore [required]

containment cooling train to OPERABLE status.

Babcock & Wilcox STS 3.6.6-2 Rev. 4.0

TSTF-538, Rev. 0 Containment Spray and Cooling Systems 3.6.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME FE. Two [required] FE.1 Restore one [required] 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months containment cooling containment cooling train to trains inoperable. OPERABLE status.

GF. Required Action and GF.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time of Condition CD, E AND or D F not met.

GF.2 --------------NOTE---------------

LCO 3.0.4.a is not applicable when entering MODE 4.

Be in MODE 4. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months HG. Two containment HG.1 Enter LCO 3.0.3. Immediately spray trains inoperable.

OR Any combination of three or more trains inoperable.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.6.1 Verify each containment spray manual, power [ 31 days operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in OR position is in the correct position.

In accordance with the Surveillance Frequency Control Program ]

Babcock & Wilcox STS 3.6.6-3 Rev. 4.0

TSTF-538, Rev. 0 CREVS 3.7.10 3.7 PLANT SYSTEMS 3.7.10 Control Room Emergency Ventilation System (CREVS)

LCO 3.7.10 Two CREVS trains shall be OPERABLE.

NOTE--------------------------------------------

The control room envelope (CRE) boundary may be opened intermittently under administrative control.

APPLICABILITY: MODES 1, 2, 3, 4, [5, and 6],

[During movement of [recently] irradiated fuel assemblies].

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One CREVS train A.1 Restore CREVS train to 7 days inoperable for reasons OPERABLE status.

other than Condition B.

B. One or more CREVS B.1 Initiate action to implement Immediately trains inoperable due to mitigating actions.

inoperable CRE boundary in MODE 1, 2, AND 3, or 4.

B.2 Verify mitigating actions 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ensure CRE occupant exposures to radiological, chemical, and smoke hazards will not exceed limits.

AND B.3 Restore CRE boundary to 90 days OPERABLE status.

Babcock & Wilcox STS 3.7.10-1 Rev. 4.0

TSTF-538, Rev. 0 CREVS 3.7.10 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. Required Action and C.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time of Condition A or B AND not met in MODE 1, 2, 3, or 4. C.2 --------------NOTE---------------

LCO 3.0.4.a is not applicable when entering MODE 4.

Be in MODE 4. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months D. ------------ NOTE ----------- D.1 Initiate action to implement Immediately Not applicable when mitigating actions.

second CREVS train intentionally made AND inoperable.

D.2 Restore at least one 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months CREVS train to Two CREVS trains OPERABLE status.

inoperable in MODE 1, 2, 3, or 4 for reasons other than Condition B.

E. Required Action and E.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time of Condition D not AND met in MODE 1, 2, 3, or

4. E.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months FD. [ Required Action and DF.1 --------------NOTE---------------

associated Completion Place in emergency mode if Time of Condition A not automatic transfer to met [in MODE 5 or 6, or] emergency mode is during movement of inoperable.

[recently] irradiated fuel -------------------------------------

assemblies.

Place OPERABLE CREVS Immediately train in emergency mode.

OR DF.2 Suspend movement of Immediately ]

Babcock & Wilcox STS 3.7.10-2 Rev. 4.0

TSTF-538, Rev. 0 CREVS 3.7.10

[recently] irradiated fuel assemblies.

Babcock & Wilcox STS 3.7.10-3 Rev. 4.0

TSTF-538, Rev. 0 CREVS 3.7.10 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME EG. [ Two CREVS trains EG.1 Suspend movement of Immediately ]

inoperable [in MODE 5 [recently] irradiated fuel or 6, or] during assemblies.

movement of [recently]

irradiated fuel assemblies.

OR One or more CREVS trains inoperable due to an inoperable CRE boundary [in MODE 5 or 6, or] during movement of [recently] irradiated fuel assemblies.

F. Two CREVS trains F.1 Enter LCO 3.0.3. Immediately inoperable in MODE 1, 2, 3, or 4 for reasons other than Condition B.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.10.1 Operate each CREVS train for [ 10 continuous [ 31 days hours with the heaters operating or (for systems without heaters) 15 minutes]. OR In accordance with the Surveillance Frequency Control Program ]

Babcock & Wilcox STS 3.7.10-4 Rev. 4.0

TSTF-538, Rev. 0 EVS 3.7.12 3.7 PLANT SYSTEMS 3.7.12 Emergency Ventilation System (EVS)

LCO 3.7.12 Two EVS trains shall be OPERABLE.

NOTE--------------------------------------------

The auxiliary building negative pressure area boundary may be opened intermittently under administrative control.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One EVS train A.1 Restore EVS train to 7 days inoperable. OPERABLE status.

B. Two EVS trains B.1 Restore auxiliary building 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months inoperable due to negative pressure area inoperable auxiliary boundary to OPERABLE building negative status.

pressure area boundary.

C. ------------ NOTE ----------- C.1 Verify at least one train of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Not applicable when Containment Spray is second EVS train OPERABLE.

intentionally made inoperable. AND C.2 Restore at least one EVS 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Two EVS trains train to OPERABLE status.

inoperable for reasons other than Condition B.

DC. Required Action and DC.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time not met. AND DC.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months Babcock & Wilcox STS 3.7.12-1 Rev. 4.0

TSTF-538, Rev. 0 EVS 3.7.12 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.12.1 Operate each EVS train for [ 10 continuous hours [ 31 days with the heaters operating or (for systems without heaters) 15 minutes]. OR In accordance with the Surveillance Frequency Control Program ]

SR 3.7.12.2 Perform required EVS filter testing in accordance In accordance with the [Ventilation Filter Testing Program (VFTP)]. with the [VFTP]

SR 3.7.12.3 Verify each EVS train actuates on an actual or [ [18] months simulated actuation signal.

OR In accordance with the Surveillance Frequency Control Program ]

SR 3.7.12.4 Verify one EVS train can maintain a pressure [ ] [ [18] months on a inches water gauge relative to atmospheric pressure STAGGERED during the [post accident] mode of operation at a TEST BASIS flow rate of [3000] cfm.

OR In accordance with the Surveillance Frequency Control Program ]

Babcock & Wilcox STS 3.7.12-2 Rev. 4.0

TSTF-538, Rev. 0 EVS 3.7.12 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.7.12.5 [ Verify each EVS filter cooling bypass damper can [ [18] months be opened.

OR In accordance with the Surveillance Frequency Control Program ] ]

Babcock & Wilcox STS 3.7.12-3 Rev. 4.0

TSTF-538, Rev. 0 Containment Spray and Cooling Systems B 3.6.6 BASES ACTIONS (continued) concluded that extending the Completion Time to [7] days for an inoperable containment spray train proves plant operational flexibility while simultaneously reducing overall plant risk. This is because the risks incurred by having the containment spray train unavailable for a longer time at power will be substantially offset by the benefits associated with avoiding unnecessary plant transitions and by reducing risk during plant shutdown operations.

B.1 and B.2 With two required containment spray trains inoperable, at least one of the required containment spray trains must be restored to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Both trains of containment cooling must be OPERABLE or Condition H is also entered. In addition, verification that LCO 3.7.10, "CREVS," is met must be made within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . With no Operable containment spray, the CREVS provides additional radiological protection to the control room staff. The Condition is modified by a Note stating it is not applicable if the second containment spray train is intentionally declared inoperable. The Condition does not apply to voluntary removal of redundant systems or components from service. The Condition is only applicable if one train is inoperable for any reason and the second train is discovered to be inoperable, or if both trains are discovered to be inoperable at the same time. The components in this degraded condition are capable of providing greater than 100% of the heat removal needs after an accident. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time is acceptable based on the redundant heat removal capabilities afforded by the containment cooling trains, the infrequent use of the Required Action, and the small incremental effect on plant risk.

BC.1 and BC.2 If the inoperable containment spray train(s) cannot be restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which overall plant risk is minimized. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 4 within 60 hours6.944444e-4 days 0.0167 hours 9.920635e-5 weeks 2.283e-5 months .

Remaining within the Applicability of the LCO is acceptable because the plant risk in MODE 4 is similar to or lower than MODE 5 (Ref. 6). The release of stored energy to the Reactor Building in the event of an accident in MODE 4 is substantially less than the energy release assumed due to an accident at power. Therefore, the challenge to the containment systems is substantially reduced. Because of the reduction in Reactor Coolant System (RCS) pressure and temperature in MODE 4, Babcock & Wilcox STS B 3.6.6-5 Rev. 4.0

TSTF-538, Rev. 0 Containment Spray and Cooling Systems B 3.6.6 the likelihood of an event is also reduced. In addition, there are more accident mitigation systems available and there is more redundancy and diversity in core heat removal mechanisms in MODE 4 than in MODE 5.

However, voluntary entry into MODE 5 may be made as it is also an acceptable low-risk state.

Required Action BC.2 is modified by a Note that states that LCO 3.0.4.a is not applicable when entering MODE 4. This Note prohibits the use of LCO 3.0.4.a to enter MODE 4 during startup with the LCO not met.

However, there is no restriction on the use of LCO 3.0.4.b, if applicable, because LCO 3.0.4.b requires performance of a risk assessment addressing inoperable systems and components, consideration of the results, determination of the acceptability of entering MODE 4, and establishment of risk management actions, if appropriate. LCO 3.0.4 is not applicable to, and the Note does not preclude, changes in MODES or other specified conditions in the Applicability that are required to comply with ACTIONS or that are part of a shutdown of the unit.

The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

The extended interval to reach MODE 4 allows additional time to attempt Babcock & Wilcox STS B 3.6.6-6 Rev. 4.0

TSTF-538, Rev. 0 Containment Spray and Cooling Systems B 3.6.6 BASES ACTIONS (continued) restoration of the containment spray train and is reasonable when considering the driving force for a release of radioactive material from the Reactor Coolant System is reduced in MODE 3.

CD.1 With one of the required containment cooling trains inoperable, the inoperable containment cooling train must be restored to OPERABLE status within 7 days. The components in this degraded condition provide iodine removal capabilities and are capable of providing at least 100% of the heat removal needs after an accident. The 7 day Completion Time was developed taking into account the redundant heat removal capabilities afforded by combinations of the Containment Spray System and Containment Cooling System and the low probability of a DBA occurring during this period.

DE.1 and DE.2 With one containment spray and one [required] containment cooling train inoperable, one of the required containment cooling trains must be restored to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . The components in this degraded condition provide iodine removal capabilities and are capable of providing at least 100% of the heat removal needs after an accident. The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time was developed taking into account the redundant heat removal capabilities afforded by combinations of the Containment Spray System and Containment Cooling System, the iodine removal function of the Containment Spray System, and the low probability of a DBA occurring during this period.

EF.1 With two of the required containment cooling trains inoperable, one of the required containment cooling trains must be restored to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . The components in this degraded condition (both spray trains are OPERABLE or else Condition G H is entered) provide iodine removal capabilities and are capable of providing at least 100% of the heat removal needs after an accident. The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time was developed taking into account the redundant heat removal capabilities afforded by combinations of the Containment Spray System and Containment Cooling System and the low probability of a DBA occurring during this period.

Babcock & Wilcox STS B 3.6.6-7 Rev. 4.0

TSTF-538, Rev. 0 Containment Spray and Cooling Systems B 3.6.6 BASES ACTIONS (continued)

FG.1 and FG.2 If the Required Actions and associated Completion Times of Condition CD, ED, or FE of this LCO are not met, the plant must be brought to a MODE in which overall plant risk is minimized. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 4 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

Remaining within the Applicability of the LCO is acceptable because the plant risk in MODE 4 is similar to or lower than MODE 5 (Ref. 6). The release of stored energy to the Reactor Building in the event of an accident in MODE 4 is substantially less than the energy release assumed due to an accident at power. Therefore, the challenge to the containment systems is substantially reduced. Because of the reduction in RCS pressure and temperature in MODE 4, the likelihood of an event is also reduced. In addition, there are more accident mitigation systems available and there is more redundancy and diversity in core heat removal mechanisms in MODE 4 than in MODE 5. However, voluntary entry into MODE 5 may be made as it is also an acceptable low-risk state.

Required Action FG.2 is modified by a Note that states that LCO 3.0.4.a is not applicable when entering MODE 4. This Note prohibits the use of LCO 3.0.4.a to enter MODE 4 during startup with the LCO not met.

However, there is no restriction on the use of LCO 3.0.4.b, if applicable, because LCO 3.0.4.b requires performance of a risk assessment addressing inoperable systems and components, consideration of the results, determination of the acceptability of entering MODE 4, and establishment of risk management actions, if appropriate. LCO 3.0.4 is not applicable to, and the Note does not preclude, changes in MODES or other specified conditions in the Applicability that are required to comply with ACTIONS or that are part of a shutdown of the unit.

The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

GH.1 With two containment spray trains or any combination of three or more containment spray and containment cooling trains inoperable, the unit is in a condition outside the accident analysis. Therefore, LCO 3.0.3 must be entered immediately.

Babcock & Wilcox STS B 3.6.6-8 Rev. 4.0

TSTF-538, Rev. 0 CREVS B 3.7.10 BASES ACTIONS (continued) and diversity in core heat removal mechanisms in MODE 4 than in MODE 5. However, voluntary entry into MODE 5 may be made as it is also an acceptable low-risk state.

Required Action C.2 is modified by a Note that states that LCO 3.0.4.a is not applicable when entering MODE 4. This Note prohibits the use of LCO 3.0.4.a to enter MODE 4 during startup with the LCO not met.

However, there is no restriction on the use of LCO 3.0.4.b, if applicable, because LCO 3.0.4.b requires performance of a risk assessment addressing inoperable systems and components, consideration of the results, determination of the acceptability of entering MODE 4, and establishment of risk management actions, if appropriate. LCO 3.0.4 is not applicable to, and the Note does not preclude, changes in MODES or other specified conditions in the Applicability that are required to comply with ACTIONS or that are part of a shutdown of the unit.

The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

D.1 and D.2 If both CREVS trains are inoperable in MODE 1, 2, 3, or 4 for reasons other than an inoperable control room boundary (i.e., Condition B), at least one CREVS train must be returned to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The Condition is modified by a Note stating it is not applicable if the second CREVS train is intentionally declared inoperable. The Condition does not apply to voluntary removal of redundant systems or components from service. The Condition is only applicable if one train is inoperable for any reason and the second train is discovered to be inoperable, or if both trains are discovered to be inoperable at the same time. During the period that the CREVS trains are inoperable, action must be initiated to implement mitigating actions to lessen the effect on CRE occupants from potential hazards while both trains of CREVS are inoperable. In the event of a DBA, the mitigating actions will reduce the consequences of radiological exposures to the CRE occupants.

At least one CREVS train must be returned to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time is acceptable based on the infrequent use of the Required Actions and the small incremental effect on plant risk.

E.1 and E.2 Babcock & Wilcox STS B 3.7.10-5 Rev. 4.0

TSTF-538, Rev. 0 CREVS B 3.7.10 If the inoperable CREVS trains cannot be restored to OPERABLE status within the associated Completion Time of Condition D in MODE 1, 2, 3, or 4, the unit must be placed in a MODE that minimizes the accident risk.

To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and in MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

[ FD.1 and FD.2

[ In MODE 5 or 6, or] during movement of [recently] irradiated fuel assemblies, if the inoperable CREVS train cannot be restored to OPERABLE status within the required Completion Time, the OPERABLE CREVS train must immediately be placed in the emergency mode. This action ensures that the remaining train is OPERABLE, that no failures preventing automatic actuation will occur, and that any active failure will be readily detected.

An alternative to Required Action DF.1 is to immediately suspend activities that could release radioactivity that might require isolation of the CRE. This places the unit in a condition that minimizes the accident risk.

This does not preclude the movement of fuel to a safe position.

Required Action DF.1 is modified by a Note indicating to place the system in the emergency mode if automatic transfer to the emergency mode is inoperable. ]

Babcock & Wilcox STS B 3.7.10-6 Rev. 4.0

TSTF-538, Rev. 0 CREVS B 3.7.10 BASES ACTIONS (continued)

[ GE.1

[In MODE 5 or 6, or] during movement of [recently] irradiated fuel assemblies, when two CREVS trains are inoperable or with one or more CREVS trains inoperable due to an inoperable CRE boundary [in MODE 5 or 6, or] during movement of [recently] irradiated fuel assemblies, action must be taken immediately to suspend activities that could result in a release of radioactivity that might require isolation of the CRE. This places the unit in a condition that minimizes the accident risk. This does not preclude the movement of fuel to a safe position. ]

F.1 If both CREVS trains are inoperable in MODE 1, 2, 3, or 4 for reasons other than an inoperable CRE boundary (i.e., Condition B), the CREVS may not be capable of performing the intended function and the unit is in a condition outside the accident analysis. Therefore, LCO 3.0.3 must be entered immediately.

SURVEILLANCE SR 3.7.10.1 REQUIREMENTS Standby systems should be checked periodically to ensure that they function properly. As the environment and normal operating conditions on this system are not severe, testing each train once every month adequately checks this system. Monthly heater operations dry out any moisture that has accumulated in the charcoal because of humidity in the ambient air. [Systems with heaters must be operated for 10 continuous hours with the heaters energized. Systems without heaters need only be operated for 15 minutes to demonstrate the function of the system.]

[ The 31 day Frequency is based on the known reliability of the equipment and the two train redundancy available.

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

Babcock & Wilcox STS B 3.7.10-7 Rev. 4.0

TSTF-538, Rev. 0 EVS B 3.7.12 B 3.7 PLANT SYSTEMS B 3.7.12 Emergency Ventilation System (EVS)

BASES BACKGROUND The function of the Emergency Ventilation System (EVS) is to collect and process potential leakage from the containment to minimize environmental activity levels resulting from all sources of containment leakage following a loss of coolant accident (LOCA).

The EVS is required to:

a. Maintain a negative pressure (minimum of 1/4 inch water gauge), with respect to outside atmosphere, within the annular space between the shield building and the containment vessel and in the penetration rooms following a LOCA; and

b. Provide a filtered exhaust path from the shield building annulus and the penetration and pump rooms following a LOCA.

The EVS filters air from the area of the active Emergency Core Cooling System (ECCS) components during the recirculation phase of a loss of coolant accident (LOCA).

The EVS consists of two independent, redundant trains. Each train consists of a prefilter, a high efficiency particulate air (HEPA) filter, an activated charcoal adsorber section for removal of gaseous activity (principally iodines), and a fan. Ductwork, valves or dampers, and instrumentation also form part of the system. The system initiates filtered ventilation of the Auxiliary Building negative pressure area following receipt of a safety features actuation signal (SFAS).

Normally, the EVS is idle during normal plant operations. Following a LOCA, a Safety Features Actuation System (SFAS) signal will start both fans and then the EVS suction dampers and the discharge dampers to the station vent stack will open. The recirculating dampers remain closed until the annulus differential pressure reaches the setpoint.

Interconnecting dampers will automatically closed if they are open by the SFAS signal in the event of a LOCA. The SFAS signal will also isolate the area being serviced by the EVS by closing the Containment Purge and Exhaust System valves and the ECCS pump room isolation valves to ensure that the EVS can draw down the shield building area to the required negative pressure.

Prefilters are provided to remove coarse airborne particles to prolong HEPA filter life. HEPA filters are provided to remove fine airborne particulates that penetrate the prefilter. The activated charcoal adsorbers are impregnated to remove methyl iodide as well as elemental iodine contaminants resulting from a LOCA.

Babcock & Wilcox STS B 3.7.12-1 Rev. 4.0

TSTF-538, Rev. 0 EVS B 3.7.12 The EVS is a standby system. During emergency operations, the EVS dampers are realigned, and fans are started to begin filtration. Upon receipt of the SFAS signal(s), normal air discharges from the negative pressure area are isolated, and the stream of ventilation air discharges through the system filter trains. The prefilters remove any large particles in the air, and any entrained water droplets present, to prevent excessive loading of the HEPA filters and charcoal adsorbers.

The EVS is discussed in the FSAR, Sections [6.2.3], [9.4.2], and 15.4.6]

(Refs. 1, 2, and 3, respectively).

APPLICABLE The design basis of the EVS is established by the large break LOCA.

SAFETY The system evaluation assumes a passive failure of the ECCS outside ANALYSES containment, such as an ECCS pump seal failure during the recirculation mode. In such a case, the system limits radioactive release to within 10 CFR 100 (Ref. 4) requirements. The analysis of the effects and consequences of a large break LOCA is presented in Reference 3. The EVS also actuates following a small break LOCA, in those cases where the unit goes into the recirculation mode of long term cooling, and to cleanup releases of smaller leaks, such as from valve stem packing.

Two types of system failures affect are considered in the accident analysis assumptions: complete loss of function, and excessive leakage.

Either type of failure may result in a lower efficiency of removal of any gaseous and particulate activity released to the ECCS pump rooms following a LOCA.

Following a LOCA, an ESFAS signal starts the EVS fans and opens the EVS suction dampers and the discharge dampers to the station vent stack , dampers located in the penetration room outlet ductwork. The ESFAS signal closes all containment isolation valves and mechanical penetration room dampers, Purge and Exhaust System valves, and the connection between the Emergency Ventilation System and the spent fuel pool areapurge system valves. The purge system fans, if running, are shut down automatically.

Babcock & Wilcox STS B 3.7.12-2 Rev. 4.0

TSTF-538, Rev. 0 EVS B 3.7.12 BASES APPLICABLE SAFETY ANALYSES (continued)

The EVS satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO Two independent and redundant trains of the EVS are required to be OPERABLE to ensure that at least one is available, assuming that a single failure disables the other train coincident with loss of offsite power.

Total system failure could result in atmospheric release from the negative pressure area boundary exceeding Reference 4 limits in the event of a Design Basis Accident (DBA).

The EVS is considered OPERABLE when the individual components necessary to maintain the negative pressure area boundary filtration are OPERABLE in both trains.

An EVS train is considered OPERABLE when its associated:

a. Fan is OPERABLE,

b. HEPA filter and charcoal adsorber are not excessively restricting flow, and are capable of performing their filtration functions, and

c. [Heater, demister,] dDuctwork, valves, and dampers are OPERABLE, and air circulation can be maintained.

The LCO is modified by a Note allowing the Auxiliary Building negative pressure area boundary to be opened intermittently under administrative controls. For entry and exit through doors, the administrative control of the opening is performed by the person(s) entering or exiting the area.

For other openings, these controls consist of stationing a dedicated individual at the opening who is in continuous communication with the control room. This individual will have a method to rapidly close the opening when a need for Auxiliary Building negative pressure area isolation is indicated.

APPLICABILITY In MODES 1, 2, 3, and 4, the EVS is required to be OPERABLE consistent with the OPERABILITY requirements of the ECCS.

In MODES 5 and 6, the EVS is not required to be OPERABLE since the ECCS is not required to be OPERABLE.

ACTIONS A.1 With one EVS train inoperable, action must be taken to restore OPERABLE status within 7 days. During this time, the remaining OPERABLE train is adequate to perform the EVS safety function.

However, the overall reliability is reduced because a single failure in the OPERABLE EVS train could result in loss of EVS function.

Babcock & Wilcox STS B 3.7.12-3 Rev. 4.0

TSTF-538, Rev. 0 EVS B 3.7.12 BASES ACTIONS (continued)

The 7 day Completion Time is appropriate because the risk contribution is less than that of the ECCS (72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time), and this system is not a direct support system for the ECCS. The 7 day Completion Time is based on the low probability of a DBA occurring during this time period, and ability of the remaining train to provide the required capability.

B.1

REVIEWERS NOTE-----------------------------------

Adoption of Condition B is dependent on a commitment from the licensee to have written procedures available describing compensatory measures to be taken in the event of an intentional or unintentional entry into Condition B.

If the Auxiliary Building negative pressure area boundary is inoperable, the EVS trains cannot perform their intended functions. Actions must be taken to restore an OPERABLE Auxiliary Building negative pressure area boundary within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . During the period that the Auxiliary Building negative pressure area boundary is inoperable, appropriate compensatory measures [consistent with the intent, as applicable, of GDC 19, 63, 64 and 10 CFR Part 100] should be utilized to protect plant personnel from potential hazards such as radioactive contamination, toxic chemicals, smoke, temperature and relative humidity, and physical security. Preplanned measures should be available to address these concerns for intentional and unintentional entry into the condition. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time is reasonable based on the low probability of a DBA occurring during this time period, and the use of compensatory measures. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time is a typically reasonable time to diagnose, plan and possibly repair, and test most problems with the Auxiliary Building negative pressure area boundary.

C.1 and C.2 With two EVS trains inoperable for reasons other than an inoperable boundary, action must be taken to restore at least one EVS train to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The Condition is modified by a Note stating it is not applicable if the second PREACS train is intentionally declared inoperable. The Condition does not apply to voluntary removal of redundant systems or components from service. The Condition is only applicable if one train is inoperable for any reason and the second train is discovered to be inoperable, or if both trains are discovered to be inoperable at the same time. In addition, at least one train of containment spray must be verified to be OPERABLE within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . In the event of an Babcock & Wilcox STS B 3.7.12-4 Rev. 4.0

TSTF-538, Rev. 0 EVS B 3.7.12 accident, containment spray reduces the potential radioactive release from the containment which reduces the consequences of the inoperable EVS trains. The Completion Time is acceptable based on the infrequent use of the Required Actions and the small incremental effect on plant risk.

DC.1 and DC.2 If the EVS train or the Auxiliary Building negative pressure area boundary cannot be restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and in MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

Babcock & Wilcox STS B 3.7.12-5 Rev. 4.0

TSTF-12-06, Transmittal of TSTF-538, Revision 0, Add Actions to Preclude Entry Into LCO 3.0.3 - RITSTF Initiatives 6b & 6c.

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TSTF-12-06, Transmittal of TSTF-538, Revision 0, Add Actions to Preclude Entry Into LCO 3.0.3 - RITSTF Initiatives 6b & 6c.

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