ML17188A084
| ML17188A084 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 03/06/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17188A082 | List: |
| References | |
| NUDOCS 9803180283 | |
| Download: ML17188A084 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. *20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 167 TO FACILITY OPERATING LICENSE NO. DPR-19.
AMENDMENT NO. 162 TO FACILITY OPERATING LICENSE NO. DPR-25.
. AMENDMENT NO. 180 TO FACILITY OPERATING LICENSE NO. DPR-29
- AND AMENDMENT NO. 178 TO FACILITY OPERATING LICENSE NO. DPR-30 COMMONWEALTH EDISON COMPANY AND MIDAMERICAN ENERGY COMPANY DRESDEN NUCLEAR POWER STATION. UNITS 2 AND 3. AND QUAD CITIES NUCLEAR POWER STATION. UNITS 1AND2 DOCKET NOS. 50-237. 50-249. 50-254 AND 50-265
1.0 INTRODUCTION
By letter dated October 27, 1997, Commonwealth Edison Company (ComEd, the licensee) submitted a request for changes to the Dresden and Quad Cities Technical Specifications (TS).
The proposed amendments would change the TS to clarify the applicability, action and surveillance requirements for the standby liquid control system (SLCS). The proposed changes would make the current TS requirements for the SLCS consistent with *the Improved Standard Technical Specifications (ISTS) contained in NUREG-1433, "Standard Technical Specifications General Electric Plants, BWR/4."
2.0 EVALUATION The purpose of the SLCS is to provide the capability for bringing the reactor from full power to a
- cold, xenon-free shutdown assuming that none of the withdrawn control rods can be inserted. It is designed to inject a quantity of boron which is required to bring the reactor from full power to 3 percent delta k/k, where k is equal to reactivity, or a more subcritical condition, considering the hot to cold reactivity swing and xenon poisoning. Additional margin is provided to compensate for possible losses and imperfect mixing of the chemical solution in the reactor water. The SLCS satisfies the requirements of 1 O CFR 50.62 on anticipated transient without scram.
The licensee has proposed to change the current SLCS TS to bring them more in alignment with the ISTS contained in NUREG-1433. The first requested TS change would remove the requirement for the SLCS to be operable in OPERATIONAL CONDITION 5 (refueling) when any control rod is withdrawn. In OPERATIONAL CONDITION 5, the reactor is shut down with the
- control rods fully inserted in any core cells that have fuel assemblies as required by Section 3.10 llJ 1
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- of the Dresden and Quad Cities TS. The one-rod-out interfock associated with the refuel position of the reactor mode switch provides protection against inadvertent criticality while the reactor is in OPERATIONAL CONDITION 5. Specifically, the reactor mode switch will be in the Refuel position (and locked) and this initiates the refuel position one-rod-out interfock which will prevent the selection of a second control rod for movement when any other control rod is not fully inserted. The reactor core is designed such that adequate shutdown margin (SOM) is maintained with one control rod fully withdrawn.
Additional protection against inadvertent criticality is also achieved in OPERATIONAL CONDITION 5 because in accordance with the TS and procedural controls, the amount of
. reactivity present in the reactor core will be constantly reduced during.core off loading. This will result in the SOM of the core being the same or greater than its initial value during the entire core off loading process. The SOM is analytically determined prior to fuel being reloaded into the reactor vessel. The calculated SOM is the acceptance criterion used in TS 3.3.A. If a control rod is withdrawn in OPERATIONAL CONDITION 5 and the SOM can not be demonstrated (i.e.,*
during reload) additional restrictions are placed on plant operations by the TS. Specifically, if adequate SOM has not been demonstrated, at least two source range monitor channels must be
- operable with the shorting links removed from the reactor protective system (RPS) circuitry prior to and any time one control rod is withdrawn from the core. In the extremely unlikely event that an inadvertent criticality occurs during this time, these additional restrictions assure that the control rod system will be automatically actuated by the RPS.
The proposed TS APPLICABILITY section has adopted the san:ie operational condition applicability for the SLCS as the ISTS. The SLCS shall be operable in modes 1 and 2 only.
The staff finds that the SLCS does not have to be operable in OPERATIONAL CONDITION 5 when any control.rod is withdrawn since adequate SDM in conjunction with the TS requirements
.for operability of the one-rod-out interfock will assure that an inadvertent criticality event will not occur during refueling operations. The staff finds this proposed change to the applicability section of the SLCS TS is acceptable.
The licensee also proposed to change the surveillance requirement section of the SLCS TS.
- The proposed change would be_to adopt the ISTS surveillance requirements. The requested changes will provide more flexibility with respect to verifying that the SLCS is operable and can perform its intended function. The proposed changes will only adopt the ISTS wording and will not eliminate any surveillance currently required by the TS.
Surveillance Requirement 4.4.A.1.c is proposed to be changed from "The heat tracing circuit is
. OPERABLE by determining the temperature of the pump suction piping to be greater than or equal to 83 ° F" to u The temperature of the pump suction piping to be greater than or equal to 83 °F." Heat trace operability is adequately encompassed by the daily verification that the pump suction is within the temperature limits. The proposed change eliminates the reference to heat tracing circuit operability and adopts wording similar to the ISTS. The proposed TS refers to the temperature of the pump suction piping as the only parameter in TS Section 4.4.A.1.c required to be monitored to determine the operability of SLCS. Ensuring that the pump suction piping temperature is greater than or equal to 83 degrees Fahrenheit will assure that the boron remains in solution and does not precipitate out into the suction piping. The temperature of 83 degrees Fahrenheit ensures that a 10 degree margin is maintained above the boron solution saturation temperature. Heat trace circuit operability will be assured by the daily verification that the pump suction is within the temperature limits. The staff finds the proposed change acceptable.
- Surveillance Requirement 4.4.A.2.c is proposed to be changed from "Verifying that each valve, manual, power operated or automatic, in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct positionD to "Verifying that each valve, manual, power operated or automatic, in the flow path that is not locked, sealed or o.therwise secured in position, is in the correct position, or can be aligned to the correct position. II The proposed allowance is added because SLCS is a manually actuated system. Operator action to realign the system provides a system initiation consistent with the safety analysis contained in the Updated Final Safety Analysis {UFSAR). The SLCS is manually in.itiated from the main control room, as directed by the emergency operating procedures, if the operator believes the reactor can not be shutdown, or kept shut down, with the control rods. The SLCS is used in the event that enough control rods can not be inserted to accomplish shutdown and cooldown in the normal manner.
The SLCS injects borated water into the reactor core to add negative reactivity to compensate for all of the various reactivity effects that could occur during plant operations. 'Verifying the correct alignment for manual, power operated, and automatic valves in the SLCS flow path provides assurance that the proper flow paths will exist for system operation. A valve is also allowed to be in the nonaccident position provided it can be aligned to the accident position from the control room, or locally by a dedicated operator at the valve control. This is acceptable since the SLCS is a manually initiated system. This surveillance also does not apply to valves that are locked, sealed, or otherwise secured in position since they are verified to be in the correct position prior to locking, sealing, or securing. This verification of valve alignment does not require any testing or valve manipulation; rather, it involves verification that those valves capable of being mispositioned are in the correct position. This SR does not apply to valves that can not be inadvertently misaligned, such as check valves. The proposed TS has adopted the STS wording and required verifications to assure proper SLCS alignment. The staff finds the proposed change to the TS acceptable.
Surveillance Requirement 4.4.A.4.a is proposed to be changed from "initiating one of the standby liquid control subsystems, including an explosive valve, and verifying that a flow path from the pumps to the reactor pressure vessel is available by pumping demineralized water into the reactor vessel. The replacement charge for the explosive valve shall be from the same manufactured batch as the one fired or from another batch which has been certified by having one of that batch successfully fired. Both injection loops shall be tested in 36 monthsD to "Initiating one of the standby liquid control subsystems, including an explosive valve, and verifying that a flow path from the pumps to the reactor pressure vessel is available. Both injection loops shall be tested in 36 months." Details* of the methods for performing the TS surveillance are currently located in the plant surveillance procedures. The design features and system operation which dictate the surveillance methods are contained in the UFSAR. Changes to the UFSAR are controlled by the provisions of 1 O CFR 50.59. Changes to procedures are controlled by administrative controls in accordance with TS 6.8.A.
The proposed TS adopts the wording of the ISTS and does not eliminate any current TS required surveillance or test. This surveillance ensures that there is a functioning flow path from the boron solution storage tank to the RPV, including the firing of an explosive valve. The details of.
the methods for performing the surveillance are iocated in the plant surveillance procedure and are administratively controlled. This information is more appropriately located in plant surveillance procedures and not in the TS.
. Section 182a of the Atomic Energy Act requires applicants for nuclear power plant operating licenses to include TS as a part of the license. The Commission's regulatory requirements related to the contents of the TS are set forth in 10 CFR 50.36. The regulation requires that the TS include items in five specific categories, including {1) safety limits, limiting safety system
.~ settings and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls. Surveillance requirements are related to test, calibration, or inspection to assure that the necessary quality of systems is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met. The staff has detennined that the detailed infonnation relating to the perfonnance of surveillance requirements does not fall within any of the above criteria. The removal of this infonnation does not affect the current TS surveillance requirements. In addition, the staff finds that sufficient regulatory controls exist under the licensee's administrative controls required by TS 6.8.A to control the details that are being removed, and which are included in the plant surveillance procedures to assure continued protection of public heath and safety.
Therefore, the removal of the procedure in the TS prescribing the testing of the SLCS in TS Section 4.4.A.4.a from the TS is acceptable.
Surveillance Requirement 4.4.A.4.b is proposed to be deleted from the TS. TS 4.4.A.4.b currently states: "Demonstrating that the pump relief valve set point is between 1455 and 1545 psig and verifying that the relief valve does not actuate during recirculation to the test tank at nonnal system* pressures.* This surveillance is currently perfonned every 18 months.
Verification of the relief valve proper operation and set point is also conducted in accordance with the plant's lnservice Test Program (IST). TS 4.0.E requires that an IST program shall be established in accordance with Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) as required by 10 CFR 50.55a. The SLCS is required by TS 4.0.E to be in the ISTprogram. Therefore the relief valve is required to be tested in accordance with 10 CFR 50.55a as implemented by TS 4.0.E. Repeating these requirements in the current SLCS TS is unnecessary. Individual relief valve proper operation and set point testing is currently, and will continue to be, conducted in accordance with the plant's IST program. The staff finds the proposed change acceptable.
Surveillance Requirement 4.4.A.4.c is proposed to be changed from "Demonstrating that the pump suction line from the storage tank is not plugged by manually initiating the system, except the explosive valves, and pumping solution in the recirculation path" to "Demonstrating that the pump suction line from the storage tank is not plugged." The proposed change adopts the wording of the ISTS and does not change the current TS surveillance requirements.. Details of the methods for perfonning surveillance are located in plant surveillance procedures, which are administratively controlled. The design features and system operation which dictate the methods are described in the UFSAR Changes to the UFSAR and the surveillance procedures are controlled by the provisions of 10 CFR 50.59.
- The proposed TS adopts the wording of the ISTS and does not eliminate any current TS required surveillance or test. This surveillance ensures that there is a functioning flow path from the boron solution storage tank through the suction piping to the SLCS pumps. The details of the methods for perfonning surveillances are located in the plant surveillance procedures and are administratively controlled. This infonnation is more appropriately located in plant surveillance procedures.
Section 182a of the Atomic Energy Act requires applicants for nuclear power plant operating licenses to include TS as part of the license. The Commission's regulatory requirements related to the contents of the TS are set forth in 10 CFR 50.36, the regulation requires that the TS include items in five specific categories, including (1) safety limits, limiting safety system settings and limiting control settings; (2) limiting conditions for operation: (3) surveillance requirements; (4) design features; and (5) administrative controls. Surveillance requirements are related to test, calibration, or inspection to assure that the necessary quality of systems is maintained, that
- facility operation will be within safety limits, and that the limiting conditions for operation will be met. The staff has determined that the detailed information relating to the performance of surveillance requirements does not fall within any of the above criteria. The removal of this information does not affect the current TS surveillance requirements. In addition, the staff finds that sufficient regulatory controls exist under the licensee's adminfstrative controls required by TS 6.8.A to control the details that are being removed, and which are included in the plant surveillance procedures to assure continued protection of the public heath and safety.
Therefore, the removal of the procedure in the TS prescribing the verification of unblocked SLCS suction piping-is acceptable.
3.0 STATE CONSULTATION
In accordance. with the Commission's regulations, the Illinois State official was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 1 O CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (63 FR 2277). Accordingly, the 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 Commission has concluded, based on the considerations ~iscussed 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 Contributor: John F. Stang Date: March 6, 1998