Text

Proposed License Amendment Request, TS 3.7.12 - ECCS Pump Room Exhaust Air Cleanup System (Preacs) Addition of Conditions/Action Statements
	ML092730468
Person / Time
Site:	North Anna
Issue date:	09/28/2009
From:	Price A; Virginia Electric & Power Co (VEPCO)
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	09-034A
	Download: ML092730468 (42)
	v • d • e

10 CFR 50.90 VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 September 28,2009 U.S. Nuclear Regulatory Commission Serial No. 09-034A Attention: Document Control Desk NL&OS/GSS RO Washington, D.C. 20555 Docket Nos. 50-338/339 License Nos. NPF-4/7 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION UNITS 1 AND 2 PROPOSED LICENSE AMENDMENT REQUEST TS 3.7.12 - ECCS PUMP ROOM EXHAUST AIR CLEANUP SYSTEM (PREACS)

ADDITION OF CONDITIONS/ACTION STATEMENTS Pursuant to 10 CFR 50.90, Dominion requests amendments, in the form of changes to the Technical Specifications to Facility Operating License Numbers NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2, respectively. The proposed changes will add new Conditions Band C with associated Action Statements and Completion Times to TS 3.7.12 and modify Conditions A and D. The changes specifically address the filtration function of ECCS PREACS and are consistent with the associated design and licensing basis accident analysis assumptions.

This change request is a revision and re-submittal of a previous request, which had been withdrawn when the NRC identified it as insufficiently detailed to complete a review. Accordingly, additional technical information and clarification have been included in the discussion. provides a discussion of and the basis for the proposed amendments.

The marked-up and proposed Technical Specifications pages are provided in Attachments 2 and 3, respectively. The associated marked-up Bases changes are provided in Attachment 4 for information only and will be implemented in accordance with the Technical Specification Bases Control Program.

The proposed changes have been reviewed and approved by the Facility Safety Review Committee. We have evaluated the proposed Technical Specification changes and have determined that they do not involve a significant hazards consideration as defined in 10 CFR 50.92. The basis for that determination is provided in Attachment 1. We have also determined that operation with the proposed changes will not result in any significant increase in the amount of effluents that may be released offsite and no significant increase in individual or cumulative occupational radiation exposure.

Therefore, the proposed amendment is eligible for categorical exclusion as set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment is needed in connection with the approval of the proposed changes. The basis for that determination is also provided in Attachment 1.

Serial No. 09-034A Docket Nos. 50-338/339 EGGS PREAGS Page 2 of 3 Dominion requests approval of the proposed changes by September 30,2010 with a 60 day implementation period following NRC approval of the license amendments.

In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the appropriate designated officials of Virginia.

If you have any questions or require additional information, please contact Mr. Thomas Shaub at (804) 273-2763.

Very truly yours, Price President - Nuclear Engineering Attachments

1. Discussion of Change

2. Marked-up Technical Specifications Changes

3. Proposed Technical Specifications Pages

4. Marked-up Technical Specifications Bases Changes Commitments made in this letter: None.

COMMONWEALTH OF VIRGINIA COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. Alan Price, who is Vice President - Nuclear Engineering of Virginia Electric and Power Company. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.

clB 1J'day of ~4td Acknowledged before me this My Commission Expires: 4 .J~ ,)(J/o .

,2009.

w'L~

VICKI L. HULL Notary Public commonwealth of VIrginia

,.OU2 Notary Public My Commllllon Expire. May 31. 2010

Serial No. 09-034A Docket Nos. 50-338/339 EGGS PREAGS Page 3 of 3 cc: U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. J. E. Reasor, Jr.

Old Dominion Electric Cooperative Innsbrook Corporate Center 4201 Dominion Blvd.

Suite 300 Glen Allen, Virginia 23060 State Health Commissioner Virginia Department of Health James Madison Building - i h floor 109 Governor Street Suite 730 Richmond, Virginia 23219 NRC Senior Resident Inspector North Anna Power Station Dr. V. Sreenivas NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North MaiI Stop 8 H4A 11555 Rockville Pike Rockville, Maryland 20852-2738 Ms. K. R. Cotton NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 16E15 11555 Rockville Pike Rockville, Maryland 20852-2738

Attachment 1 (Serial No. 09-034A)

Discussion of Change North Anna Power Station Units 1 and 2 Virginia Electric and Power Company (Dominion)

09-034A Docket Nos. 50-338/339 Attachment 1 Page 1 of 17 Discussion of Changes 1.0 Introduction Pursuant to 10 CFR 50.90, Virginia Electric and Power Company (Dominion) requests an Amendment to Facility Operating License Numbers NPF-4 and NPF-7 in the form of changes to the Technical Specifications (TS) for North Anna Power Station Units 1 and

2. The proposed changes will add new Conditions Band C with associated Action Statements and Completion Times to TS 3.7.12 and modify Conditions A and D to specifically address the filtration function of Emergency Core Cooling System (ECCS)

Pump Room Exhaust Air Cleanup System (PREACS). The proposed changes are consistent with the associated design and licensing basis accident analysis assumptions.

The current Technical Specifications are overly restrictive when considering the current design analysis/dose analysis of record. The design analysis/dose analysis of record includes consideration of ECCS leakage in the determination of primary ventilation filtration requirements. However, TS requirements do not account for ECCS leakage in determining the need for filtration and are therefore overly restrictive. Therefore, any equipment issues with the shared portions of the ventilation system (e.g., filtration train bypass dampers) adversely affect both Units, which could result in a two unit simultaneous shutdown regardless of the actual lack of need for filtration to meet the dose analysis of record. TS 3.0.3 has been entered multiple times during the life of the plant due to this condition, and each time the filtration function was not required for the design basis. To avoid the unnecessary risk associated with a dual unit shutdown coupled with the fact that the filtration function of the PREACS is normally not necessary to meet the accident dose analysis, Dominion has developed and modified Actions and required Completion Times to consider low ECCS leakage conditions, and better reflect the time it takes to evaluate and repair an equipment issue with the filter system.

The filtration requirements are stipulated in the Technical Specification - Ventilation Filter Testing Program and include particulate filtration, charcoal adsorption capabilities, and system bypass leakage, etc. Therefore, when "filtration" or "filters" are used in this document it includes both particulate filtration and gaseous adsorption.

The proposed changes qualify for categorical exclusion from an environmental assessment as set forth in 10 CFR 51.22(c)(9). Therefore, no environmental impact statement of environmental assessment is needed in connection with the approval of the proposed changes.

2.0 Proposed Changes The proposed changes will modify Conditions A and D and add new Conditions Band C with associated Action Statements and Completion Times to TS 3.7.12, as follows:

09-034A Docket Nos. 50-338/339 Attachment 1 Page 2 of 17

Condition A is being modified to remove the filtration function from the operability requirements of a PREACS train. The actions addressing the ventilation exhaust function (cooling) of the ECCS PREACS train remain unchanged.

The proposed two new Conditions (B and C) with Actions and Completion Times will address the operability of the filtration function of ECCS PREACS only.

Condition D (pump room boundary) is also being modified to be consistent with new Conditions 8 and C to account for ECCS leakage.

The existing remaining Conditions are renumbered due to the addition of the two new Conditions.

PROPOSED ACTIONS FOR TS 3.7.12 (bold/italicized indicate changes)

ACTIONS

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

Separate Condition entry is allowed for each Function.

CONDITION REQUIRED ACTION COMPLETION TIME A. One ECCS PREACS A.1 Restore ECCS PREACS train to 7 days train inoperable for OPERABLE status.

reasons other than Condition B.

B. One ECCS PREACS B.1.1 Verify ECCS leakage log is less than 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months train inoperable due the maximum allowable unfiltered to inoperable filtration leakage.

capability.

AND B.1.2 Verify by field walkdown that ECCS Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months leakage is less than the maximum thereafter allowable unfiltered leakage.

AND B.1.3 Restore ECCS PREACS train to 30 days OPERABLE status.

OR B.2 Restore ECCS PREACS train to 7 days OPERABLE status.

C. Two ECCS PREACS C.1.1 Verify ECCS leakage log is less than 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months trains inoperable due the maximum allowable unfiltered to inoperable filtration leakage.

capability.

AND C.1.2 Verify by field walkdown that ECCS Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months leakage is less than the maximum thereafter allowable unfiltered leakage.

AND

09-034A Docket Nos. 50-338/339 Attachment 1 Page 3 of 17 G.1.3 Restore at least one EGGS PREAGS 14 days train to OPERABLE status.

OR G.2 Restore one EGGS PREAGS train to OPERABLE status. 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months D. Two ECCS PREACS 0.1.1 Verify EGGS leakage log is less than 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months trains inoperable due to the maximum allowable unfiltered inoperable ECCS pump leakage.

room boundary AND affecting filtration capability. 0.1.2 Verify by field walkdown that EGGS Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months leakage is less than the maximum thereafter allowable unfiltered leakage.

AND 0.1.3 Restore EGGS pump room boundary 14 days to OPERABLE status.

OR 0.2 Restore ECCS pump room boundary to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months OPERABLE status.

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 not met. AND E.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months The TS Bases B 3.7.12 are being modified to incorporate the basis for the new Conditions and are included for information. The Bases changes will be incorporated into the TS in accordance with the Bases Control Program after NRC approval of the proposed TS changes.

3.0 Design/Licensing Bases System Design/Operation TS 3.7.12 addresses the ECCS PREACS. This ventilation system consists both of unit-specific subsystems (Unit 1 and Unit 2 Safeguards Exhaust), a shared subsystem (Auxiliary Building Central Exhaust), and the associated common ductwork. The system is operated both during normal operations and during accident conditions. The system is connected to several other subsystems which are shutdown and isolated during an accident as a result of an ECCS actuation. During normal operation ECCS PREACS provides cooling and the filters are normally bypassed.

09-034A Docket Nos. 50-338/339 Attachment 1 Page 4 of 17 The ECCS PREACS filters potentially radioactive air from the area of the active ECCS components during the recirculation phase of a loss-of-coolant-accident (LOCA). In addition, the ventilation system provides cooling for the ECCS pumps. The ventilation system includes the provision of multiple exhaust fans, once-through ventilation discharge through the vent stack, and the capability of diverting the effluent through the common HEPAlcharcoal filter banks.

During emergency operations, the ECCS PREACS dampers are realigned to begin filtration through charcoal adsorbers. Specifically, the charcoal adsorber assembly adsorbs radioiodines before releasing the exhaust air to the environment. The existing accident (dose) analysis of record assumes that filtration by ECCS PREACS does not begin for 60 minutes following an accident, which is reflected in the current TS Bases Section B 3.7.12 Applicable Safety Analyses. The licensing basis for ECCS PREACS is for the ventilation exhaust to be filtered within 60 minutes following an accident, and to be capable of providing filtration efficiencies as stated within Technical Specifications Sections 3.7.12 and 5.5.10.

Dose Consequences The design basis for ECCS PREACS is to maintain both off-site radiation dose and radiation dose to the Control Room operators within the allowable limits, as described in UFSAR Section 15.4.1.8, Dose Consequences of a Loss of Coolant Accident. The ECCS PREACS is only used to mitigate the consequences of a design basis LOCA.

The operation of ECCS PREACS subsystems during normal and accident conditions is described in UFSAR Sections 9.4.2, Auxiliary Building (ventilation); 9.4.6, Engineered Safety Features Area (ventilation); 9.4.8, Auxiliary Building HEPAlCharcoal Filter Loops and 12.2.2.1, Auxiliary Building (ventilation).

The existing LOCA dose analysis of record was submitted to the NRC in a letter dated October 3, 2006 [Sections 2.6 and 4 of Attachment 1 to Reference 6] and reviewed and approved by the NRC in a letter dated March 13, 2007 [Reference 7]. This dose analysis modified the previously approved alternate source term analysis [Section 3.1 of to Reference 10] to account for changes associated with the GOTHIC re-analysis of containment. The assumptions in the dose analysis relevant to this change for the filtration function of the PREACS as documented in Reference 6 are:

The source term and core power were unchanged.

The EAB, LPZ, and control room XlQ's were unchanged.

The dose conversion factors remained consistent with Federal Guidance Reports 11 and 12.

The core release fractions and phases were consistent with RG 1.183.

The chemical form of the iodines released from the fuel and also found in the sump was consistent with RG 1.183.

The off-site and control room breathing rates were consistent with RG 1.183.

09-034A Docket Nos. 50-338/339 Attachment 1 Page 5 of 17

ECCS leakage was assumed to begin 14 minutes into the LOCA with the start of an Outside Recirculation Spray pump.

Credit was taken for the timed release of radionuclides into the containment sump over 1.8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months in accordance with RG 1.183.

The containment sump volume was modeled as increasing over the first 8000 seconds of the LOCA.

Auxiliary Building (PREACS) filtration was aligned at 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months post LOCA.

ECCS leakage was modeled using different scenarios. They ranged from 3,400 cc/hr of only unfiltered leakage, 34,400 cc/hr of only filtered leakage, and combinations of both. The limiting unfiltered ECCS leakage scenario was 3,400 cc/hr (note that the allowable operating leakage limit is one-half of the analyzed amount consistent with RG 1.183).

The PREACS and control room filter efficiencies for aerosols and elemental iodine remained at 98% and 95%, respectively.

The PREACS filter efficiency for organic iodides was increased to 90%.

The Control Room filter efficiency for organic iodides was increased to 95%.

The Control Room volume was increased to 7.910E+04 fe.

The control room was isolated at t=O hours post-LOCA from a safety injection (Sl) signal.

The control room unfiltered inleakage rate was assumed to be 250 cfm. This is supported by tracer gas testing, which resulted in 150 cfm inleakage in a non-pressurized alignment of the control room.

One emergency control room fan was aligned to provide the control room with 900 cfm of filtered outside air at 60 minutes after the control room was isolated. Unfiltered inleakage of 250 cfm remains constant even during pressurization.

Control room filtered recirculation flow was not credited.

No credit was taken for the MCR bottled air system.

The flash fraction for iodines in the ECCS leakage analysis was consistent with RG 1.183 at 10%.

No credit was taken for holdup in the auxiliary building.

No changes to the analysis of record were required to support this PREACS License Amendment Request because the current analysis assumes 3400 cc/hr of unfiltered ECCS Leakage. As documented in Reference 6, the dose consequences remain as follows:

09-034A Docket Nos. 50-338/339 Attachment 1 Page 6 of 17 Current Design Basis LOCA Dose Results Control Room Exclusion Low (Rem TEDE) Area Population Boundary Zone (Rem TEDE) (Rem TEDE)

Total Dose Consequences including contributions from 4.1 2.1 0.2 containment, ECCS and RWST leakage 10 CFR 50.67 dose limits 5 25 25 Ventilation/Cooling The ECCS PREACS, in conjunction with other normally operating ventilation systems, provides environmental control of temperature in the ECCS pump room areas. The charging/high head safety injection pump motors have internal fans that provide design cooling requirements without reliance on ECCS PREACS. The safeguards building has sufficient cooling capability to ensure the associated equipment, Low Head Safety Injection (LHSI) and Outside Recirculation Spray (OSRS) pumps, remain operable for at least 60 minutes without the safeguards exhaust fans in service (in the event the ventilation system is not running at the beginning of a DBA). The licensing basis for ECCS PREACS is to provide ventilation exhaust within 60 minutes of the DBA at greater than the minimum required air flow from the Safeguards Building, as stated within Technical Specifications Section 5.5.10. Thus, ECCS pump/equipment cooling requirements are met, consistent with the accident analysis assumptions.

4.0 Technical Analysis & Safety Considerations To meet the design/licensing basis requirement to maintain both off-site radiation dose and radiation dose to the Control Room operators within the allowable limits, the analyses for one accident (large break LOCA) take credit in certain circumstances for filtration by ECCS PREACS. This filtration may be needed when ECCS is placed into the recirculation mode for long-term cooling to accommodate airborne radiation from potential water leakage from ECCS components (Le., "ECCS leakage"). If the ECCS leakage is less than a specific calculated value of 3400 cc/hr (which corresponds to an operational leakage limit of 1700 cc/hr), the dose calculations show that both the off-site radiation dose and radiation dose to the Control Room operators will be maintained within the NRC approved analysis-of-record dose, even with no ECCS PREACS filtration.

09-034A Docket Nos. 50-338/339 Attachment 1 Page 7 of 17 Monitoring of EGGS Leakage The amount of EGGS leakage is an operating parameter that is periodically monitored by Operations and is documented in the Operations logs. EGGS leakage is evaluated as: 1) the amount of EGGS leakage located within the EGGS pump rooms (where exhaust air is filtered), and 2) the amount of EGGS leakage located outside of the EGGS pump rooms (unfiltered). Since the air within the EGGS pump rooms is exhausted by the EGGS PREAGS and is aligned to the filters post-accident, a larger amount of EGGS leakage can be accommodated in these rooms. The maximum amount of EGGS leakage that can be accommodated both in the pump rooms (filtered) and remaining areas (unfiltered) is established by the assumption in the analysis (dose) of record. This relationship is shown in Figure 15.4-111 of Revision 44 of the UFSAR. If all measured EGGS leakage is conservatively assumed to be located within unfiltered areas, then as long as the total leakage is less than the analyzed value for maximum allowable unfiltered leakage as documented in Figure 15.4-111 of Revision 44 of the UFSAR, the radiation dose will be maintained within the NRG approved analysis of record.

Procedures which address monitoring of EGGS leakage include provisions such that the EGGS leakage measurement will be adjusted by conservative calculation to reflect the accident conditions (i.e., higher leakage due to higher system operating pressure).

Therefore, there is assurance that actual leakage during an accident will be less than or equal to the operating parameter of EGGS leakage identified prior to the accident.

There is adequate margin of safety provided between the operating parameter limit for EGGS leakage to the maximum allowable unfiltered leakage. Dose calculations include several conservatisms, including the fact that the EGGS leakage rate is increased in the calculation by a factor of two above its operating limit.

System Leakage Performance There are several potential sources for EGGS leakage, such as charging pump (also known as High Head Safety Injection or HHSI pump) seals, valve packing, or valve body-to-bonnet; however, pump seals are typically the largest source. The North Anna charging pump seals have experienced excessive leakage in the past, which was subsequently resolved through modification (during 2003-05) and improved installation and operating procedures.

Review of the operating history of the EGGS components during the past several years indicates the following observations:

Review of the EGGS leakage indicates that total leak rate (after calculated adjustment to accident conditions) since 2003 is typically less than 500 cc/hr (usually 100-300 cc/hr). This includes all leakage, both in areas with unfiltered ventilation and in areas served by EGGS PREAGS, which is well below the value for maximum allowable unfiltered leakage of 1700 cc/hr. For example, the total EGGS leakage on May 27, 2009 was 85 cc/hr in Unit 1 and 135 cc/hr in Unit 2,

09-034A Docket Nos. 50-338/339 Attachment 1 Page 8 of 17 and on May 1, 2008 the total ECCS leakage was 366 cc/hr in Unit 1 and 310 cc/hr in Unit 2.

Occasionally, a leakage (most often associated with a pump seal) between 500 and 1000 cc/hr (calculated leak rate) has been noted and then repaired promptly (for example, twice during 2008).

Since the pump seals were modified, there have been only two instances of individual components with calculated leakage greater than 1700 cc/hr, and in both cases actions were immediately initiated to isolate the component (valve packing on October 20, 2003 and pump endbell on July 4, 2005).

Based on this operating experience, Dominion considers it very unlikely that ECCS leakage will be above 1700 cc/hr during a LOCA.

Evaluation of Potential Pump Seal Leakage As part of our GSI-191 initiative, an evaluation was completed of the mechanical seal assembly of the North Anna charging pumps (HHSI), Low Head Safety Injection (LHSI) pumps and Outside Recirculation Spray (OSRS) Pumps and submitted to the NRC in a letter dated February 27, 2009 [Reference 9]. The evaluation confirms that DBA-generated debris will not be a mechanism to cause additional mechanical seal leakage.

The tandem seal design of the LHSI and OSRS pumps minimizes the probability of DBA-generated debris from entering between the seal faces. In particular, clean water sources are used to fill the annular volume between the inboard and outboard seals, which will minimize the possibility of debris laden process water entering between the seal faces. Therefore, this seal configuration prevents excessive pump seal wear and ensures there is no significant impact on pump flow or seal leakage.

Independent evaluations, completed by Westinghouse and MPR Associates Inc.,

confirmed that the performance of the HHSI pump mechanical seals will not be affected by debris-laden water from the containment sump in a post-LOCA environment. Using debris loading data from the North Anna GSI-191 initiative, it was shown that the debris is too large to pass through the primary seal and cause wear and that no sizeable amount of debris will be entrained in the fluid flushing the seals due to the flushing fluids low velocity. As stated in Reference 9 [page 16 of Attachment 1 to Reference 9]:

"The evaluation concluded that the HHSI pump seals would be adequately cooled and seal faces would not wear significantly from particulate debris during the mission time. In addition, the amount of debris entering the seal chamber would be insignificant such that the function of the seal internal mechanism would not be affected. The seal analysis determined that no additional leakage is anticipated as a result of debris-laden pumped fluid. Therefore, the HHSI pump seals meet performance criteria and would continue to function as required for the duration of the mission time."

09-034A Docket Nos. 50-338/339 Attachment 1 Page 9 of 17 For these reasons, the evaluations show that debris would not be expected to be a failure mechanism for the mechanical seal assemblies in the charging pumps, LHSI pumps, or OSRS pumps and the pumps will perform their design basis functions during the 3D-day mission time, with no increase in ECCS leakage.

Time Needed to Complete Repairs There are several conditions which could affect the filtration function but not affect the cooling function of ECCS PREACS. For example, a problem with the HEPA filter or charcoal adsorber or the associated housing may just affect a single train. In this case, two trains remain operable to perform the cooling function using either the flow path of the remaining filter or the flow path of the bypass ductwork. However, a problem with closure or leak-by through the bypass dampers, or with control of the filter & bypass dampers, on one of the subsystems may affect the filtration capability of both trains.

The time necessary to complete repairs on the filter assembly and/or associated dampers may be significant, depending on the specific problems discovered. For example, damper or filter assembly bypass leak-by requires a significant time to identify the source of the issue, get it resolved, and perform required leak testing. Leak testing requires vendor support, and it takes some time in order to arrange for one of the two qualified vendors to provide personnel and equipment on site.

Another potential scenario is the discovery of a common-mode failure problem that affects a significant amount of the charcoal in both filter banks, such as a manufacturing flaw discovered by the vendor after previous shipments had been installed. It would take well over a week to resolve this problem. Assuming that replacement charcoal could be received quickly (normal charcoal delivery is a few weeks), and based on reasonable durations for maintenance, planning and scheduling, a total time of 9~ days is estimated. Since the work may take approximately 50 percent of the LCO time (i.e.,

proposed 14 days for two inoperable trains of filtration) to complete, this would still allow for recovery time should any of the above items run into problems, and would allow for a planned/controlled down power if required.

Filters fail because of charcoal:

Problem identification - ~ day

Planning Work Orders & Ordering charcoal -1day

Receiving Charcoal - 4 days

Health Physics setup/support - 1 day

Removing old charcoal - 1 day

Installing new charcoal - 1 to 3 days

Post-maintenance testing - ~ day

Restoration- clearing tags and placing in service - ~ day Total time = 9~ days

09-034A Docket Nos. 50-338/339 Attachment 1 Page 10 of 17 Based on the above discussion of estimated diagnosis and repair times, the following proposed Required Actions and Completion Times are being requested.

Basis for Extended Completion Time - One Train Inoperable With one ECCS PREACS train inoperable due to loss of its filtration capability, action must be taken within one hour to determine if the filtration capability is required (Action B.1.1). This is determined based on comparing the most recent ECCS system operational leakage log value against design basis unfiltered leakage assumptions. The leakage log is always maintained current by Operations as part of the walkdowns which are performed at least once per shift by the on-shift reactor operators. If the current total ECCS leakage is less than the maximum allowable unfiltered leakage assumed in the design bases, then the filtration capability of ECCS PREACS is not required and an extended period to restore operability can be applied. During this time, both trains remain operable to perform the ventilation exhaust/cooling function.

The proposed action to restore the inoperable train's filtration function to operable status within 30 days (Action B.1.3) is reasonable, consistent with:

(a) the dose analysis shows that no filtration is required when ECCS leakage is less than the maximum allowable unfiltered leakage, (b) significant margin exists between operating limits and actual dose limits, (c) the time necessary to complete repairs on the filter assembly and/or associated dampers may be significant, and (d) the other train of ECCS filtration remains operable to perform its intended safety function if needed.

In addition, the proposed change includes a surveillance requirement that requires ECCS leakage operating parameters to be monitored by walking down the areas every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months in order to determine whether or not filtration capability is required (Action B.1.2). Establishing monitoring on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency is based on operating history, which indicated that a sudden change in ECCS leakage is not expected, and the conservatisms in the design basis dose calculations.

If total ECCS leakage is equal to or greater than the maximum allowable unfiltered leakage limit then the filtration capability of ECCS PREACS is required and actions must be taken to restore Operability of the filter within seven days (Action B.2) consistent with an inoperable PREACS train for any other reason.

Basis for Extended Completion Time - Two Trains Inoperable Both trains of ECCS PREACS may be made inoperable without affecting the ventilation exhaust (cooling) function by potential problems such as an inoperable bypass damper or a charcoal adsorber issue. The proposed change requires action be taken within one hour to determine if the filtration capability is required (Action C.1.1). This is determined

09-034A Docket Nos. 50-338/339 Attachment 1 Page 11 of 17 based on comparing the most recent EGGS system operational leakage log value against design basis unfiltered leakage assumptions. The leakage log is always maintained current by Operations as part of the walkdowns which are performed at least once per shift by the on-shift reactor operators. If the current total EGGS leakage is less than the maximum allowable unfiltered leakage, then the filtration capability of EGGS PREAGS is not immediately required and an extended period to restore operability can be applied. During this time, both trains remain operable to perform the ventilation exhaust/cooling function.

If the filtration capability of EGGS PREAGS is not required, actions to restore the filtration function and restore at least one inoperable train to operable status within the proposed 14 days (Action G.1.3) are reasonable, consistent with:

(a) the dose analysis shows that no filtration is required when EGGS leakage is less than the maximum allowable unfiltered leakage, (b) significant margin exists between operating limits and actual dose limits, (c) operating history indicates that a sudden change in EGGS leakage to greater than the maximum allowable unfiltered leakage is not expected, (d) the time necessary to complete repairs on the filter assembly and/or associated dampers may be significant, and (e) unnecessary two-unit shutdown has associated risks.

In addition, the proposed change includes a surveillance requirement that requires EGCS leakage operating parameters to be monitored by walking down the areas every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months in order to determine whether or not filtration capability is required (Action C.1.2). Establishing monitoring on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency is based on operating history, which indicated that a sudden change in ECCS leakage is not expected, and the conservatisms in the design basis dose calculations.

If total ECCS leakage is equal to or greater than the maximum allowable unfiltered leakage limit then the filtration capability of ECCS PREACS is required and actions must be taken to restore Operability of at least one train (Action C.2). This must be done within one hour, consistent with the dose analysis which has no filtration for the first 60 minutes following an accident.

Basis for Extended Completion Time - Pump Room Boundary Breaching an EGCS pump room boundary would affect the filtration function of both trains of ECCS PREACS, since the exhaust system may not be able to maintain a negative pressure on the boundary. However, the ventilation/cooling function would not be affected since the charging pump motors have internal fans that provide design cooling requirements without reliance on the central exhaust fans and the Safeguards Area boundaries are to the exterior atmosphere. Since the inlet to the exhaust ductwork in each pump cubicle in Safeguards is located just above the motor, cooler outside air

09-034A Docket Nos. 50-338/339 Attachment 1 Page 12 of 17 entering through a breach in a cubicle or the building general area (e.g., the outside door), would eventually be drawn into the cubicle, and out by the exhaust system.

Thus, the ventilation and cooling function will not be affected by boundary breaches.

The proposed change requires action be taken within one hour to determine if the filtration capability is required (Action 0.1.1). This is determined based on the Unit's operational ECCS leakage. The leakage log is always maintained current by Operations as part of the walkdowns which are performed at least once per shift by the on-shift reactor operators. If the current total ECCS leakage is less than the maximum allowable unfiltered leakage, then the filtration capability of ECCS PREACS is not immediately required and an extended period to restore operability can be applied.

Ouring this time, the ability to perform the ventilation exhaust/cooling function remains unaffected.

If the filtration capability of ECCS PREACS is not required, actions to restore the filtration function and restore the boundary to operable status within 14 days (Action 0.1.3) are reasonable, consistent with:

(a) the dose analysis shows that no filtration is required when ECCS leakage is less than the maximum allowable unfiltered leakage, (b) significant margin exists between operating limits and actual dose limits, (c) operating history indicates that a sudden change in ECCS leakage to greater than the maximum allowable unfiltered leakage is not expected, and (d) the time necessary to complete repairs and perform required testing may be significant.

In addition, the proposed change includes a surveillance requirement that requires ECCS leakage operating parameters to be monitored by walking down the areas every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months in order to determine whether or not filtration capability is required (Action 0.1.2). Establishing monitoring on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency is based on operating history, which indicated that a sudden change in ECCS leakage is not expected, and the conservatisms in the design basis dose calculations.

If total ECCS leakage is equal to or greater than the maximum allowable unfiltered leakage limit then the filtration capability of ECCS PREACS is required and actions must be taken to restore Operability of the pump room boundary (Action 0.2). This must be done within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , consistent with the existing Condition and the intent of GOC-1 9 to have compensatory measures provided to protect the operators from radioactive contamination.

09-034A Docket Nos. 50-338/339 Attachment 1 Page 13 of 17 5.0 Regulatory Safety Analysis No Significant Hazards Consideration The proposed changes will add new Conditions Band C with associated Action Statements and Completion Times to TS 3.7.12 and modify Conditions A and 0 to specifically address the filtration function of ECCS PREACS and to be more consistent with the associated design analysis. Dominion has evaluated whether or not a significant hazards consideration is involved with the proposed changes by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of Amendment" as discussed below:

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

The proposed changes do not adversely affect accident initiators or precursors and do not alter the design assumptions, conditions, or configuration of the facility. The new conditions only affect the filtration function of ECCS PREACS, which is an accident mitigation function, so accident initiation probability is not impacted. Regarding significance of the proposed changes relative to the accident consequences, the new conditions remain consistent with existing design assumptions (i.e., dose calculations show that the filtration function is not required when ECCS leakage is less than the maximum allowable unfiltered leakage) and filtration is required to be operable as required to support the design analysis assumptions.

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

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

The addition of the new Conditions Band C with associated Action Statements and Completion Times to TS 3.7.12 and modification of Condition 0 to address the filtration function of ECCS PREACS does not impact the accident analysis or associated assumptions. The new conditions only address actions to be taken when portions of ECCS PREACS (an accident mitigation system) is out-of-service.

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

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

09-034A Docket Nos. 50-338/339 Attachment 1 Page 14 of 17 The proposed changes do not alter the manner in which safety limits, limiting safety system settings, or limiting conditions for operation are determined. The proposed new conditions recognize that there may be limited leakage situations when filtration is not required to meet the accident analysis assumptions.

Allowing safety equipment to be inoperable while it is not required is not reducing the analyzed margin of safety.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Based upon the above, Dominion concludes that the proposed changes represent 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.

Regulatory Requirements The proposed changes will add new Conditions Band C with associated Action Statements and Completion Times to TS 3.7.12 and modify Conditions A and D to specifically address the filtration function of ECCS PREACS and to be more consistent with the associated design analysis. The filtration function of ECCS PREACS serves to limit both on-site and off-site dose. As described in UFSAR Chapter 15, the only accident in which ECCS PREACS is credited is the Loss-of-Coolant Accident. UFSAR Section 15.4.1.8.8 shows that calculated dose results for both on-site and off-site are less than the regulatory limits of 10 CFR 50.67 and of GDC 19. Since the proposed changes will add new conditions that require ECCS leakage to be within the limits established in UFSAR Chapter 15 assuming no credit for ECCS PREACS filtration, it is concluded that the proposed changes comply with all regulatory requirements.

General Conformance with General Design Criteria (GDC)

North Anna was originally designed to meet the draft GDC published in 1967.

Construction permits for Units 1 and 2 were issued on February 19, 1971. The GDC, Appendix A to 10 CFR 50, were published February 20, 1971. Dominion attempted to comply with the intent of the newer criteria to the extent practical, recognizing previous design commitments. As a result, the NRC review assessed the plant design against the GDC published in 1971 and concluded that the design conformed to the newer criteria. The North Anna Safety Evaluation Report (NUREG-0053) was issued in June 1976.

Criterion 19 - Control Room The control room habitability systems include radiation shielding, redundant emergency air filtering and air conditioning systems, radiation monitoring, lighting, and fire protection equipment.

09-034A Docket Nos. 50-338/339 Attachment 1 Page 15 of 17 The North Anna control room is common to both units. Sanitary facilities and potable water are located in the control room, and food can be brought to the control room as needed. Radiation protection is provided by shielding (walls and slabs), radiation monitoring, emergency filtration, and separate and independent control room isolation and pressurization systems.

The control room is designed to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions. Adequate radiation protection has been provided to ensure that radiation exposures to personnel occupying the control room during the 30-day period following a DBA will not exceed 5 rem Total Effective Dose Equivalent (TEDE).

Evaluations of the LBLOCA and Fuel Handling accidents, using Alternate Source Term, demonstrate that North Anna meets the GOC 19 criterion of 5 rem TEOE, with unfiltered inleakage into the control room envelope at 250 cfm for LOCA and 400 cfm for fuel handling accident. A submittal of DBA analyses using the AST methodology was approved by the NRC on June 15, 2005 in amendments 240 and 241 [Reference 8] for North Anna Units 1 and 2, respectively. The Large Break LOCA is the limiting radiological event. As described in Section 3, the LOCA alternate source term dose analysis was modified to account for changes associated with the GOTHIC re-analysis of containment [References 6 & 7]. The design basis accidents, dose analyses, and consequences are described in Chapter 15 of the UFSAR.

The proposed change to the TS will ensure that compliance with requirements equivalent to 10 CFR 50, Appendix A, GOC 19 is maintained. 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 Commission's 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.

6.0 Environmental Assessment This amendment request meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) as follows:

(i) The amendment involves no significant hazards consideration.

As described above in Section 5.0, the proposed changes involve no significant hazards consideration.

(ii) There is no significant change in the types or significant increase in the amounts of any effluents that may be released off-site.

09-034A Docket Nos. 50-338/339 Attachment 1 Page 16 of 17 The proposed changes do not involve the installation of any new equipment, or the modification of any equipment that may affect the types or amounts of effluents that may be released off-site. Therefore, there is no significant change in the types or significant increase in the amounts of any effluents that may be released off-site.

(iii) There is no significant increase in individual or cumulative occupation radiation exposure.

The proposed changes do not involve physical plant changes. Therefore, there is no significant increase in individual or cumulative occupation radiation exposure. Although the new conditions may lead to an increase relative to the current practice in the dose consequence of an accident (if an accident were to occur while the system is in an action statement), the effect is not adverse in that dose will still be well within the design and licensing limits.

Based upon the above, Dominion concludes that the proposed changes meet the criteria specified in 10 CFR 51.22 for a categorical exclusion from the requirements of 10 CFR 51.22 relative to requiring a specific environmental assessment by the Commission.

7.0 Conclusion This evaluation demonstrates that the proposed changes to the Technical Specifications and the Bases are appropriate. The ECCS PREACS remains capable of performing its intended safety function.

09-034A Docket Nos. 50-338/339 Attachment 1 Page 17 of 17 8.0 References The following references support the accuracy of the proposed Technical Specifications and Bases changes and the evaluation in this document:

1. Technical Specifications (TS), Section 3.7.12, Emergency Core Cooling System (ECCS) Pump Room Exhaust Air Cleanup System (PREACS), Amendments 231/212

2. Technical Specifications Bases, Section B 3.7.12, Emergency Core Cooling System (ECCS) Pump Room Exhaust Air Cleanup System (PREACS), Revision 20.

3. UFSAR Section 9.4.8, "Auxiliary Building HEPA/Charcoal Filter Loops"

4. UFSAR Section 12.2, "Ventilation"

5. UFSAR Section 15.4.1, "Loss of Reactor Coolant From Ruptured Pipes or From Cracks in Large Pipes Including Double Ended Rupture That Actuates the Emergency Core Cooling System (Large Break Loss of Coolant Accident)"

6. Dominion letter Serial No.06-849, "Virginia Electric and Power Company North Anna Units 1 and 2 Proposed Technical Specification Change and Supporting Safety Analysis Revision to Address Generic Safety Issue 191," dated October 3, 2006

7. NRC letter, North Anna Power Station Units 1 and 2, Issuance of Amendments regarding Technical Specification Change per Generic Safety Issue (GSI) 191 (TAC Nos. MD3197 and 3198), dated March 13,2007

8. NRC letter, Issuance of Amendment Nos. 240 and 221 on Implementation of Alternate Source Term (TAC Nos. MC0776 and MC0777) - North Anna Power Station Units 1 and 2, dated June 15, 2005

9. Dominion letter Serial No.09-003, "Virginia Electric and Power Company North Anna Units 1 and 2 Updated Supplemental Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage On Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated February 27,2009

10. Dominion letter Serial No. 04-494A, "Virginia Electric and Power Company (Dominion) North Anna Power Station Units 1 and 2 Response to Request for Additional Information Proposed Technical Specification Changes Implementation of Alternate Source Term Revised Dose Analysis and Technical Specification Changes," dated November 3, 2004

Attachment 2 (Serial No. 09-034A)

Marked-up Technical Specifications Changes North Anna Power Station Units 1 and 2 Virginia Electric and Power Company (Dominion)

ECCS PREACS 3.7.12 3.7 PLANT SYSTEMS 3.7.12 Emergency Core Cooling System (EeeS) Pump Room Exhaust Air Cleanup System (PREACS)

LCO 3.7.12 Two ECCS PREACS trains shall be OPERABLE.

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

The ECeS pump room boundary openings not open by design may be opened intermittently under administrative control.

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

ACTIONS REQUIRED ACTION A. One EC REACS train A.I Restore ECCS PREACS inoperable. train to OPERABLE status.

B. Two ECCS PREACS trains 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months inoperable due to inoperable ECCS pump room boundary.

C. Required Actio nd C.1 Be in MODE 3.

associated mpletion Time n met. AND C.2 Be in MODE 5.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.12.1 Operate each EeCS PREACS train for 31 days

~ 10 continuous hours with the heaters operating.

North Anna Units 1 and 2 3.7.12-1 Amendments 231/212

PROPOSED ACTIONS FOR TS 3.7.12 (bold/italicized indicate changes)

ACTIONS

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

Separate Condition entry is allowed for each Function.

CONDITION REQUIRED ACTION COMPLETION TIME A. One ECCS PREACS A.1 Restore ECCS PREACS train to 7 days train inoperable for OPERABLE status.

reasons other than Condition 8.

B. One ECCS PREACS 8.1.1 Verify EeCS leakage log is less 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months train inoperable due than the maximum allowable to inoperable unfiltered leakage.

filtration capability.

AND B.1.2 Verify by field walkdown that Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months EeeS leakage is less than the thereafter maximum allowable unfiltered leakage.

AND B.1.3 Restore EeCS PREACS train to 30 days OPERABLE status.

OR B.2 Restore EeCS PREACS train to 7 days OPERABLE status.

C. Two ECCS PREACS C.1.1 Verify EeCS leakage log is less 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months trains inoperable than the maximum allowable due to inoperable unfiltered leakage.

filtration capability.

AND C.1.2 Verify by field walkdown that Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months EeeS leakage is less than the thereafter maximum allowable unfiltered leakage.

AND C.1.3 Restore at least one ECeS 14 days PREACS train to OPERABLE status.

OR C.2 Restore at least one ECeS PREACS train to OPERABLE 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months status.

D. Two EGGS PREAGS 0.1.1 Verify ECCS leakage log is less 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months trains inoperable due than the maximum allowable to inoperable ECGS unfiltered leakage.

pump room boundary AND affecting filtration capability. D.1.2 Verify by field walkdown that Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ECCS leakage is less than the thereafter maximum allowable unfiltered leakage.

AND D.1.3 Restore ECCS pump room 14 days boundary to OPERABLE status.

OR D.2 Restore EGCS pump room 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months boundary to OPERABLE status.

e. Required Action and £.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 AND met.

E.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months 2

Attachment 3 (Serial No. 09-034A)

Proposed Technical Specifications Changes North Anna Power Station Units 1 and 2 Virginia Electric and Power Company (Dominion)

ECCS PREACS 3.7.12 3.7 PLANT SYSTEMS 3.7.12 Emergency Core Cooling System (ECCS) Pump Room Exhaust Air Cleanup System (PREACS)

LCO 3.7.12 Two ECCS PREACS trains shall be OPERABLE.

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

The ECCS pump room boundary openings not open by design may be opened intermittently under administrative control.

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

ACTIONS

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

Separate Condition entry is allowed for each Function.

CONDITION REQU I RED ACTI ON COMPLETION TIME A. One ECCS PREACS train A.l Restore ECCS PREACS 7 days inoperable for reasons train to OPERABLE other than Condition B. status.

North Anna Units 1 and 2 3.7.12-1 Amendments

ECCS PREACS 3.7.12 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. One ECCS PREACS train B.1.1 Verify EeCS leakage 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months inoperable due to log is less than the inoperable filtration maximum allowable capability. unfiltered leakage.

AND B.1.2 Verify by field Once per walkdown that ECCS 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months leakage is less than thereafter the maximum allowable unfiltered leakage.

AND B.1.3 Restore ECCS PREACS 30 days train to OPERABLE status.

OR B.2 Restore ECCS PREACS 7 days train to OPERABLE status.

North Anna Units 1 and 2 3.7.12-2 Amendments

Eces PREACS 3.7.12 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME C. Two ECCS PREACS trains C.1.1 Verify ECCS leakage 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months inoperable due to log is less than the inoperable filtration maximum allowable capability. unfiltered leakage.

AND C.1.2 Verify by field Once per walkdown that ECCS 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months leakage is less than thereafter the maximum allowable unfiltered leakage.

AND C.1.3 Restore at least one 14 days ECCS PREACS train to OPERABLE status.

OR C.2 Restore at least one 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months ECCS PREACS train to OPERABLE status.

North Anna Units 1 and 2 3.7.12-3 Amendments

ECCS PREACS 3.7.12 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME D. Two ECCS PREACS trains D.1.1 Verify ECCS leakage 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months inoperable due to log is less than the inoperable ECCS pump room maximum allowable boundary affecting unfiltered leakage.

filtration capability.

AND 0.1.2 Verify by field Once per walkdown that ECCS 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months leakage is less than thereafter the maximum allowable unfiltered leakage.

AND D.1.3 Restore ECCS pump room 14 days boundary to OPERABLE status.

OR D.2 Restore ECeS pump room 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months boundary to OPERABLE status.

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 not met. AND E.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.12.1 Operate each ECCS PREACS train for 31 days 2 10 continuous hours with the heaters operating.

North Anna Units 1 and 2 3.7.12-4 Amendments

ECCS PREACS 3.7 .12 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.12.2 Actuate each ECCS PREACS train by aligning 31 days Safeguards Area exhaust flow and Auxiliary Building Central exhaust flow through the Auxiliary Building HEPA filter and charcoal adsorber assembly.

SR 3.7.12.3 Perform required ECCS PREACS filter testing In accordance in accordance with the Ventilation Filter wi th the VFTP Testing Program (VFTP).

SR 3.7.12.4 Verify Safeguards Area exhaust flow is 18 months diverted and each Auxiliary Building filter bank is actuated on an actual or simulated actuation signal.

SR 3.7.12.5 Verify one ECCS PREACS train can maintain a 18 months on a negative pressure relative to adjacent STAGGERED TEST areas during post accident mode of BASIS operation.

North Anna Units 1 and 2 3.7.12-5 Amendments

Attachment 4 (Serial No. 09-034A)

Marked-up Technical Specifications Bases Changes (For Information Only)

North Anna Power Station Units 1 and 2 Virginia Electric and Power Company (Dominion)

ECCS PREACS B 3.7.12 B 3.7 PLANT SYSTEMS B 3.7.12 Emergency Core Cooling System (ECeS) Pump Room Exhaust Air Cleanup System (PREACS)

BASES BACKGROUND The ECCS PREACS filters air from the area of the active ECCS components during the recirculation phase of a loss of coolant accident (LOCA). The ECCS PREACS, in conjunction with other normally operating systems, also provides environmental control of temperature in the ECCS pump room areas.

~

The fCCS PREACS consists of two subsystems, the Safeguards Area Ventilation subsystem and the Auxiliary Building Central Exhaust subsystem. There are two redundant trains in the Safeguards Area Ventilation subsystem. Each train of the Safeguards Area Ventilation subsystem consists of one Safeguards Area exhaust fan, prefilter, and high efficiency particulate air (HEPA) filter and charcoal adsorber assembly for removal of gaseous activity (principally iodines)

(shared with the other unit), and controls for the Safeguards Area exhaust filter and bypass dampers. Ductwork, valves or dampers, and instrumentation also form part of the subsystem. The subsystem automatically initiates filtered ventilation of the safeguards pump room following receipt of a Containment Hi-Hi signal from the affected unit.

The Auxiliary Building Central exhaust subsystem consists of the following: three redundant central area exhaust fans (shared with other unit), two redundant filter banks consisting of HEPA filter and charcoal adsorber assembly for removal of gaseous activity (principally iodines) (shared with the other unit), and two redundant trains of controls for the Auxiliary Building Central exhaust subsystem filter and bypass dampers (shared with the other unit). Ductwork~

valves or dampers, and instrumentation also form part of the subsystem. The subsystem initiates filtered ventilation of the charging pump cubicles following manual actuation.

The Auxi 1i ary Buildi ng fi Her banks are shared by the Safeguards Area Ventilation subsystem and the Auxiliary Building Central Exhaust subsystem. Either Auxiliary Building filter bank may be aligned to either ECCS PREACS train. These filter banks are also used by the Auxiliary (continued)

North Anna Units 1 and 2 B 3.7.12-1 Revision 0

INSERT FOR PAGE B 3.7.12-1 The charging/high head safety injection pump motors have internal fans that provide design cooling requirements without reliance on the central exhaust fans. The associated equipment in the Safeguards Building, Low Head Safety Injection (LHSI) and Outside Recirculation Spray (OSRS) pumps, remain operable for at least 60 minutes without the safeguards exhaust fans in service.

4

- NUCLEAR DESIGN INFORMATION PORTAL-fees PREACS B 3.7.12 BASES BACKGROUND Building General area exhaust, fuel building exhaust, (continued) decontamination building exhaust, and containment purge exhaust.

One Safeguards Area exhaust fan 1S normally operating and dampers are aligned to bypass the HEPA filters and charcoal adsorbers. During emergency operations. the Eees PREACS dampers are realigned to begin filtration. Upon receipt of the actuating Engineered Safety Feature Actuation System si9nal(5), normal air discharges from the Safeguards Area room are diverted through the filter banks. Two Auxiliary Building Central Exhaust fans are normally operating. Air discharges from the Auxiliary Building Central Exhaust area are manually diverted through the filter banks. Required Safeguards Area and Auxiliary Building Central Exhaust area fans are manually actuated if they are not already operating. The prefilters remove any large particles in the air to prevent excessive loading of the HEPA filters and charcoal adsorbers.

The fecs PREACS is discussed in the UFSAR, Section 9.4 (Ref. 1) and it may be used for normal. as well as post accident, atmospheric cleanup functions. The primary purpose of the heaters is to maintain the relative humidity at an acceptable level during normal operations. generally consistent with iodine removal efficiencies per Regulatory Guide 1.52 (Ref. 3). The heaters are not required for ------------------

post-accident conditions. J \f !Sees ~\(f,-e.

)(~~N

,r;..-:.....-- ~)

APPLICABLE The design basis of the Eecs PREACS ;s establish SAFETY ANALYSES large break LOCA. The system evaluation assumes outside containment. such as safety injection mp leakage, during the recirculation mode. In such a case. the system limi~radioactive release to within the control room operator dose limits of 10 CFR 50. Appendix A, GOC-19 (Ref. 4) for alternative source terms. The analysis of the effects and consequences of a large break LOCA is presented in Reference 2. The ECCS PREACS also may actuate following a small break LOCA, in those cases where the ECeS goes into the recirculation mode of long tenm cooling. to clean up releases of smaller leaks, such as from valve stem packing.

The analyses assume the filtration by the ECCS PREACS does not begin for 60 minutes following an accident.

The ECeS PREACS satisfies Criterion 3 of 10 CFR 50.36(c) (2) (i i).

North Anna Units 1 and 2 B 3.7.12-2 Revision 20

ECCS PREACS B 3.7.12 BASES lCO Two redundant trains of the EC S PREACS are required to be OPERABIFto ensure that at lea t one is available. Total system failure could result in exceeding the control room operator dose limits of 10 eFR 50, Appendix A, GDC-19 (Ref. 4) for alternative source terms.

ECCS PREACS is considered OPERABLE when the individual components necessary to maintain the [CCS pump room

___~~A~tjOn are OPERABLE in both trains.

C\leA;\~--Y An EeCS PREACS train is considered OPERABLE when its associated:

a. Safeguards Area exhaust fan is OPERABLE;

b. One Auxiliary Building HEPA filter and charcoal adsorber assembly (shared with the other unit) is OPERABLE;

c. One Auxiliary Building Central exhaust system fan (shared with other unit) is OPERABLE;

d. Controls for the Auxiliary Building Central exhaust system filter and bypass dampers (shared with the other unit) are OPERABLE;

e. HEPA filter and charcoal adsorbers are not excessively restricting flow. and are capable of performing their filtration functions; and

f. Ductwork, valves, and dampers are OPERABLE.

Portions of ECCS PREACSmay be removed from service (e.g.,

tag out fans, open ductwork, etc.). in order to perform required testing and maintenance. The system is OPERABLE in this condition if it can be restored to service and perform its function within 60 minutes following dn accident.

In addition, the required Safeguards Area and charging pump cubicle boundaries for charging pumps not isolated from the Reactor Coolant System must be maintained, including the integrity of the walls, floors, ceilings, ductwork, and access doors, except for those openings which are left open by design, including charging pump ladder wells.

(continued)

North Anna Units 1 and 2 B 3.7.12-3 Revision 34

- NUCLEAR DESIGN INFORMATION PORTAL-ECCS PREACS B 3.7.12 BASES LCO The LCO is modified by a Note allowing the ECCS pump room (continued) boundary openings not open by design 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 ECCS pump room isolation is indicated.

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

In MODE 5 or 6, the ECCS PREACS is not required to be OPERABLE since the ECCS is not ~re~q~u~i!r~ed~~~~EillWl~ ~ __

fb~ ~()'N5 G"\'l'~ 1'J\1\--,.J \"\l\Ql"o? R -

(~ ~f\E) \~S'1M~~ ~\J\.~

ACTIONS A* 1 ','K.\\t-"\l51> fl.~ ~)

With one Eces PREACS train inoperabl , action must be taken to restore OPERABLE status within 7 ys. During this time, the remaining OPERABLE train is adequate to perform the ECCS PREACS function.

( .---ru~ ~f...~ R.....OLl,}l' 1~~'N~~~~ The 7 day Completion Time is appropriate because the risk I ~~ (,CC$ ~Ul"f fU)b'ft'~ contribution is less han that for the ECeS (72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 1\.",Sf'\'-\ L"M\£ Ie p~ Completion Time), and ~Ais systeffi is Aet d direct s~ppeft sYite~ fer the ECCS. he 7 day Completion Time is based on

-f\S ~~. the low probability of a Design Basis Accident (DBA)

\ Cb6UNG-occurring during this time period, and ability of the remaining train to~ovide the required capability. ,~o~~~ ~ ~s~~~

W\~ ar+.1!!R"""N'1'N ~"'I~tl COACI:I1"f'eAt hntAf'~ eitwo EC~S. PREACS trainsiW6'll:H-G--f'eo!;..l,l-I-1~V--- c <no '1:>>

~~e +9&& 9f ~R~p<----- .. ~abll't~, therefore t LCO 3.0.3 must be entered immediately.

If t~e ~ccs ~tlm~ room boundary is iAe~erablet t~e EGGS PREACS trai r:1S car:1r:1Qt ~el form tne; r i AteAded fUAeti BAS. Aeti DRS ~1:I5t be takeR to restore aA OPERAgLE ECCS p~mp foom bgYRdar¥

~(ithiR 24 h~~r~. BtlriA~ the ~erlad that the ECCS pump room boundary is inoperable, appropriate compensatory measures consistent with the intent of GOC 19 should be utilized to (continued)

North Anna Units 1 and 2 B 3.7.12-4 Revision 0

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- NUCLEAR DESIGN INFORMATION PORTAL-ECCS PREACS B 3.7.12 BASES ACTIONS

~

~ (continued) *

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protect control room operators from potential hazards such as radioactive contamination. 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 OBA 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 feeS pump room C£g~l and ~2~

bQIHNary.

If the ECCS PREACS train(s) or Eees pump room 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.

SURVEILLANCE SR 3.7.12.1 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 a month provides an* adequate check on this

. system. Monthly heater operations dry out any moisture that may have accumulated in the charcoal and HEPA filters from humidity 1n the ambient air. The system must be operated

~ 10 continuous hours with the heaters energized. The 31 day Frequency is based on the known reliability of equipment and the two train redundancy available.

SR 3.7.12.2 This SR verifies that Safeguards Area exhaust flow and Auxiliary Building Central EXhaust subsystem flow, when actuated from the control room. diverts flow through the Auxiliary Building HEPA filter and charcoal adsorber .J assembly for the operating train. Exhaust flow is diverted "

(continued) t-:

North Anna Units 1 and 2 B 3.7.12-5 Revision 0

INSERT FORPAGEB 3.7.12-4 ACTIONS B.l.l, B.1.2 and B.1.3 With one ECCS PREACS train inoperable due to loss of its filtration capability, action must be taken within one hour to determine if the filtration capability is required (Action B.l.l). This is determined based on comparing the most recent ECCS system operational leakage log value against design basis unfiltered leakage assumptions. If the current total ECCS leakage is less than the maximum allowable unfiltered leakage assumed in the design bases, then the filtration capability of ECCS PREACS is not required and an extended period to restore operability can be applied. The value for "maximum allowable unfiltered ECCS leakage" is documented in the UFSAR (reference 6). During this time, both trains remain operable to perform the ventilation exhaust/cooling function.

(For example, a problem with the filter itself or its housing affects a single train, and both trains remain operable to perform the ventilation function using either the flow path of the remaining filter or the flow path of the bypass ductwork.)

The action to restore the inoperable train's filtration function to operable status within 30 days (Action B.1.3) is reasonable, consistent with:

(a) the dose analysis shows that no filtration is required when ECCS leakage is less than the maximum allowable unfiltered leakage, (b) significant margin exists between operating limits and actual dose limits, (c) the time necessary to complete repairs on the filter assembly and/or associated dampers may be significant, and (d) the other train of ECCS filtration remains operable to perform its intended safety function if needed.

In addition, ECCS leakage is required to be monitored by walking down the areas every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months in order to determine whether or not filtration capability is required (Action B.1.2). Establishing monitoring on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency is based on operating history, which indicated that a sudden change in ECCS leakage is not expected, and the conservatisms in the design basis dose calculations.

If total ECCS leakage is equal to or greater than the maximum allowable unfiltered leakage limit then the filtration capability of ECCS PREACS is required and actions must be taken to restore Operability of the filter within seven days consistent with an inoperable PREACS train for any other reason.

C.l.l, C.1.2, and C.1.3 If two ECCS PREACS trains are inoperable due to loss of their filtration capability, action must be taken within one hour to determine if the filtration capability is required (Action C.l.1). This is determined based on the Unit's operational ECCS leakage. If the current total ECCS leakage is less than the maximum allowable unfiltered leakage, then the filtration capability of ECCS PREACS is not immediately required and an extended period to restore operability can be applied. During this time, both trains remain operable to perform the ventilation exhaust/cooling function. Both trains of ECCS PREACS may be made inoperable without affecting the ventilation exhaust function by potential problems such as an inoperable bypass damper or a charcoal adsorber issue.

If the filtration capability of ECCS PREACS is not required, actions to restore the filtration function and restore at least one inoperable train to operable status within 14 days (Action C.I.3) are reasonable, consistent with; (a) the dose analysis shows that no filtration is required when ECCS leakage is less than the maximum allowable unfiltered leakage, (b) significant margin exists between operating limits and actual dose limits, (c) operating history indicates that a sudden change in ECCS leakage to greater than the maximum allowable unfiltered leakage is not expected, (d) the time necessary to complete repairs on the filter assembly and/or associated dampers may be significant, and (e) unnecessary two-unit shutdown has associated risks.

In addition, ECCS leakage is required to be monitored by walking down the areas every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months in order to determine whether or not filtration capability is required (Action C.1.2). Establishing monitoring on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency is based on operating history, which indicated that a sudden change in ECCS leakage is not expected, and the conservatisms in the design basis dose calculations.

If total ECCS leakage is equal to or greater than the maximum allowable unfiltered leakage limit then the filtration capability ofECCS PREACS is required and actions must be taken to restore Operability of at least one train within sixty minutes, consistent with the dose analysis. The analysis assumes the filtration by PREACS does not begin for sixty minutes following an accident (see Applicable Safety Analyses).

D.Ll, D.1.2, and D.1.3 Breaching an ECCS pump room boundary would affect the filtration function of both trains of ECCS PREACS, since the exhaust system may not be able to maintain a negative pressure on the boundary. However, the ventilation/cooling function would not be affected since the charging pump motors have internal fans that provide design cooling requirements without reliance on the central exhaust fans, and the Safeguards Area boundaries are to the exterior atmosphere. Since the inlet to the exhaust ductwork in each pump cubicle in Safeguards is located just above the motor, cooler outside air entering through a breach in a cubicle or the building general area (e.g., the outside door),

would eventually be drawn into the cubicle, and out by the exhaust system. Thus, the ventilation and cooling function will not be affected by boundary breaches.

If two ECCS PREACS trains are inoperable due to loss of the pump room boundary, action must be taken within one hour to determine if the filtration capability is required (Action D.l.l). This is determined based on the Unit's operational ECCS leakage. If the current total ECCS leakage is less than the maximum allowable unfiltered leakage, then the filtration capability of ECCS PREACS is not immediately required and an extended period to restore operability can be applied. During this time, the ability to perform the ventilation exhaust/cooling function remains unaffected.

If the filtration capability of ECCS PREACS is not required, actions to restore the filtration function and restore the boundary to operable status within 14 days (Action D.l.3) are reasonable, consistent with:

(a) the dose analysis shows that no filtration is required when ECCS leakage is less than the maximum allowable unfiltered leakage, (b) significant margin exists between operating limits and actual dose limits, 2

(c) operating history indicates that a sudden change in ECCS leakage to greater than the maximum allowable unfiltered leakage is not expected, and (d) the time necessary to complete repairs and perform required testing may be significant.

In addition, ECCS leakage is required to be monitored by walking down the areas every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months in order to determine whether or not filtration capability is required (Action D.l.2). Establishing monitoring on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency is based on operating history, which indicated that a sudden change in BeCS leakage is not expected, and the conservatisms in the design basis dose calculations.

If total ECCS leakage is equal to or greater than the maximum allowable unfiltered leakage limit then the filtration capability ofECCS PREACS is required and actions must

[be taken to restore an operable EeCS pump room boundary within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . During the period ... ] (r'RO~ 9"l>~. e '$.'1 .\'2 ~"")

3

ECCS PREACS B 3.7.12 BASES REFERENCES 2. UFSAR, Section 15.4.

(continued)

3. Regulatory Guide 1.52 (Rev. 2).

4. 10 CFR 50, Appendix A.

5. NUREG-0800, Rev. 2, July 1981.

t.. ~~ ... 'lt I ~'b"<<'~ \$,,-\_,,0 North Anna Units 1 and 2 B 3.7.12-7 Revision 0

v t e Letter Sequence Request
TAC:ME2414, (Approved, Closed) TAC:ME2413, (Approved, Closed)
Initiation Request, Request Acceptance Administration Questions 11 March 2010 26 April 2010 Answers 8 April 2010 Results Approval Other: ML111730070
MONTHYEAR2010-03-11 [Table View]

ML092730468

Text

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