ML20206C015
| ML20206C015 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/22/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20206C013 | List: |
| References | |
| NUDOCS 9904300155 | |
| Download: ML20206C015 (4) | |
Text
4 p te k UNITED STATES y
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NUCLEAR REGULATORY COMMISSION 1
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 219 AND 200 TO FACILITY OPERATING LICENSE NOS. NPF-4 AND NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY
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NORTH ANNA POVER STATION. UNITS NO.1 AND NO. 2
1.0 INTRODUCTION
By letter dated July 28,1998, Virginia Electric and Power Company (VEPCO, the licensee) submitted proposed Technical Specification changes that would revise the testing acceptance
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criteria for the casing cooling and outside recirculation spray pumps for North Anna Power Station, j
Units 1 and 2. Specifically, the proposed changes will delete the current Surveillance Requirement 4.6.2.2.1.b and instead incorporate the Inservice Testing Program surveillance requirements for the casing cooling and outside recirculation spray pumps. The proposed changer will revise the current acceptance criteria to be consistent with the acceptance criteria specifieJ in the Standard Technical Specifications for Westinghouse plants (NUREG-1431).
The NRC's basis for approving the proposed changes to the Technical Specifications is given below.
2.0 TECHNICAL SPECIFICATION CHANGE The current operability requirements for the Casing Cooling and Recirculation Spray Systems include measurement of discharge pressure and verificatien that recirculation flow discharge pressure is above specific pressure head values established in the Technical Specifications.
The Surveillance Requirement 4.6.2.2.1.b for both Units 1 and 2 reads:
Verifying, that on recirculation flow, each outside recirculation pump develops a discharge pressure of a 115 psig and each casing cooling pump develops a discharge pressure of 2 58 psig (*) when tested pursuant to Specification 4.0.5.
(*) 46 psig for Unit 2 The licensee proposes to replace the current Surveillance Requirement 4.6.2.2.1.b for both Units 1 and 2 with the following:
Verify each RS and casing cooling pump's developed head at the flow test point is greater than or equal to the required developed head. The frequency shall be in accordance with the Inservice Testing Prograi.i s
9904300155 990422 PDR ADOCK 05000338 P
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' 2.1 Bases for Acceptance The containment Recirculation Spray (RS) System, along with the Containment Quench Spray System, is designed to limit post-accident pressure and temperature in the containment to less than the design values and depressurize the containment to subatmospheric pressures. Two RS pumps are located inside the containment and two are located outside. Following a Loss of Coolant Accident (LOCA), the water accumulated in the containment sump provides a suction supply for the RS pumps. The Casing Cooling suh km which is considered a part of the outside RS subsystem, cools the water on the suction side of the RS pumps to increase their net positive suction head.
The current Technical Specificat'?ns Surveillance Requirements require that each outside RS pump develops a discharge pressure head equal to or greater than 115 psig and that each Casing Cooling pump develops a discharge pressure head equal to or greater than 58 psig for Unit 1 and 46 psig for Unit 2, when tested pursuant to TS 4.0.5.
The proposed changes verify that the developed head at the flow test points for the Casing Cooling and outside RS pumps is greater than or equal to the required developed head that is in agreement witn the vendor's pump curves used in the system calculation.
Instead of verifying the discharge pressure head against specific values which are currently stated in the TS, the licensee's proposed surveillance requirement verifies that the developed head is consistent with the system design basis calculations. These calculations indicate the pump discharge pressure necessary to assure the capability of the system to mitigate the consequences of a design basis accident.
10 CFR 50.36(c)(2)(ii) provides four criteria for determining whether a TS limiting condition for operation is required for an item. These criteria are:
Criterion 1.
Installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal deCradation of the reactor coolant system pressure boundary.
Criterion 2.
A process variable, design feature, or operating restriction that is an initial condition of a design basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
Criterion 3.
A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
Criterion 4.
A structure, syste.n, or component which operating experience cr probabilistic risk assessment nas shown to be significant to public health and safety.
Operability of the RS and Casing Cooling systems meets Cnierion 3.
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. The licensee's proposed changes provide a more accurate assessment of the pump performance and are consistent with the acceptance criteria specified in NUREG-1431, which requires the verification of each RS and Casing Cooling pump's developed head at the flow test point to be greater than or equal to the required head.
The licensee's proposed changes are acceptable since (1) the pump performance data obtained with the periodic test procedures are in agreement with the vendor's pump curves and (2) use of the proposed acceptance criteria during periodic testing will demonstrate that the systems are capable of supplying the requireo design basis flow to the containment in a post accident situation.
TS 4.0.5 states that Surveillance Requirements for Inservice inspection and Inservice Testing of ASME Code Class 1,2, and 3 components shall be performed in accordance with Section XI of the ASME Code and applicable addenda as required by 10 CFR 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i).
The proposed changes to the TS refer to the Inservice Testing Program for testing frequency, and the Inservice Testing of ASME Code Class 1,2, and 3 components is performed in accordance with Section XI of the ASME Code.
3.0 STATE CONSULTA'QN in accordance with the Cu.n ilssion's regulations, the Virginia State official was notified of the proposed issuance of the amendments. The State official had no comment.
4.0 ENVIRONMENTAL CONSIDERATION
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These amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined i'110 CFR Part 20 and change a j
surveillance requirement. The NRC staff has determined (1) that the amendments involve no significant increase in the amounts and no significant change in the types of any effluent that may be released offsite and (2) that there is no significant in::rease in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration, and there has been no public comment on such finding (63 FR 48272). Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The proposed Technical Specifications changes described in the licensee's submittal of July 28,1998, are acceptable since the pump performance data obtained with the periodic test procedures are in agreement with the ventior's pump curves and the changes are consistent with the acceptance criteria in NUREG-1441.
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' The Commission has concluded, based on the considerations discussed above, that: (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 issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: T. Cerovski Date: April 22,1999 i
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