ML20245H885
| ML20245H885 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 02/28/1989 |
| From: | Keuter D SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Knighton G NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20245H889 | List: |
| References | |
| AGM-NPP-89-029, AGM-NPP-89-29, NUDOCS 8903060073 | |
| Download: ML20245H885 (12) | |
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)sMun SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street. P.o. Box 15830, Sacramento CA 95852-1830,(916) 452-3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA FEB 2 81989 !
AGM/NPP 89-029 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Hashington, DC 20555 Docket No. 50-312 Rancho Seco Nuclear Generating Station License No. DPR-54 PROPOSED AMENDMENT NO. 130. REVISION 1 Attention: George Knighton Based on NRC comments and in accordance with 10 CFR 50.90, the Sacramento Municipal Utility District has revised Proposed Amendment No.130, originally submitted June 21, 1988. Proposed Amendment No. 130, Revision 1 replaces the original submittal in its entirety.
By letter dated December 4, 1984, the Commission issued its SER confirming the ability of the 12-inch equalization valves to close against the buildup of Containment pressure in the event of a DBA/LOCA. Proposed Amendment No. 130 Revision 1 adds operating requirements to the Technical Specifications which are designed to provide proper limitations and conditions on Reactor Building pressure equalization operations during power operation. Proposed Amendment No.130, Revision 1 also modifies an existing purge system operation requirement.
Attachment I contains the Safety Analysis Report and the No Significant Hazards Consideration for the changes made by Proposed Amendment No. 130, Revision 1. Attachmeret II contains the Technical Specification pages affected by Proposed Amendment No. 130, Revision 1.
Pursuant to 10 CFR 50.51(b)(1), the Radiological Health Branch of the California State Depart lnent of Health Services has been informed of this proposed amendment by mailed copy of this submittal.
Since this submittal is a revision to Proposed Amendment No. 130, no additional license fees are required. It is requested that this proposed amendment be made effective within 30 days following receipt of the approved amendment by the District.
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RANCHO SECO NUCLEAR GENERATING STATloN O 1444o Twin Cities Road, Herald, CA 95638-9799;(209) 333-2935
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George Knighton AGM/NPP-89-029
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Members of your staff with questions requiring additional information or clarification may contact Mr. Richard Mannheimer at. (209) 333-2935,-
extension 4919.
State of Californi& (elf 9
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SACRAMENTO COUNTY County of Sacramento lMY'c0MM.EXP.NOV. 20, 1992 Dan R. Keuter, being first duly sworn, deposes and says: that he is Assistant General Manager, Nuclear Plant Manager of Sacramento Municipal Utility District'(SMUD), the licensee herein; that he has executed the foregoing document; that the statements made in this document are true and correct to the best of his knowledge, information, and belief, and that he is authorized to execute this document on behalf of said licensee.
QC Dan R. Keuter Assistant General Manager Nuclear Plant Manager Subscribed and affirmed to before me on this day of 244e4a/ , 1989.
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&cLab/JK ElJ/abeth L. Gandy No':ary Public [
Attachments cc: J.'B'. Martin, NRC, Halnut Creek A. D'Angelo, NRC, Rancho Seco J. S. McGurk, State of California I
ATTACHMENT I Safety Analysis Report and No Significant Hazards Consideration i
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PROPOSED AMENDMENT NO. 130, Revision 1 LOG NO. 649, Rev. 1 Safety Analysis PAGE l'of 9 SAFETY ANALYSIS REPORT Description of Chanae Effect Technical Specification changes to address operation of the 12-inch j Reactor Building pressure equalization valves when the plant is in the -
" Power Operation" mode (>2% of rated power as defined by Technical '
Specification 1.2.5).. Also, effect Technical Specification changes to appropriately define the purge system operation requirements. l 1
Add referencs to Reactor Building equalization isolatian in Technical l Specificatica 1.ble 3.5.1-1, Process Instrumentation, item 9. j Remove the t cold shutdown or refueling" operator action statement in Table 3.5.1-1, Process Instrumentation, item 9, column.(C). Modify the action statement to ensure the equalization valves and the purge valves are properly addressed in relation to high-range Reactor Building area radiation monitor operability and provide consistency and proper cross-referencing within the Technical Specifications. Change the Minimum Channels Operable requirement in column (B) of Table 3.5.1-1 for the high-range Reactor Building area radiation monitors from 1 to 2.
Add reference to Reactor Building pressure equalization valves to Technical Specification 3.6.8.
Modify Technical Specification Section 3.8, Fuel Loading and Refueling, to provide appropriate refueling restrictions on the operability of the Reactor Building purge system and the Reactor Building Stack radiation monitor.
Technical Specification 3.8.10 is modified. Existing Technical Specification 3.8.11 is renumbered 3.8.13. A new refueling Technical Specification is added and numbered 3.8.11.
Decrease the required surveillance interval for the Reactor Building equalization valves from 6 months to 3 months in Technical Specification 4.4.1.2.3(d) and (e).
Add reference to Reactor Building equalization and add the term " Vent" to Table 4.22-1, item B.
Reason for Chanae By letter dated December 27, 1983, the District provided information to the NRC enabling completion of their review concerning the operability of the 12-inch pressure equalization valves. The District demonstrated the ability of the 12-inch pressure equalization valves to close against the buildup of Containment pressure in the event of a DBA.
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1 PROPOSED AMENDMENT NO. 130, Revision 1 LOG NO. 649 Rev. 1 '
Safety Analysis PAGE 2 of 9 1
By letter dated December 4,1964, the.NRC issued their SER entitled i
" Demonstration of Containment Purge and Vent Valve Operability." The SER j acknowledged the ability of the 12-inch pressure equalization valves to close during a DBA. In addition, grior to approving the use of the 12-inch pressure equalization valves to equalize Rtactor. Building pressure during reactor operation (>2% rated power), the NRC required the following two items to be i implemented:
- 1. Install'a high-range monitor on the Reactor Building purge line (Reactor Building Stack). Make the monitor operational to meet NUREG-0737, Item II.F.1.
- 2. Revise the Rancho Seco Technical Speci Deations. Reduce the leak testing interval for the 12-inch pressure equalization valves from 6 months to 3 months.
Item 1 is complete. Radiation monitor R-15044 has been installed to meet NUREG-0737 Item II.F.1. Proposed Amendment No. 130 meets the NRC requirement stated in item 2 above. In addition to the Technical Specification changes required by item 2, other changes are proposed which will properly reference and control Reactor Building equalization at power operation.
The existing "at cold shutdown or refueling" operator action statement in Table 3.5.1-1, item 9, column (C) represents an unnecessary restriction on purging operations. When the plant is in cold shutdown, no condition should be placed on the purge valves with regard to operability of the Reactor Building high-range area radiation monitors. Also, a refueling restriction on the purge valves in Table 3.5.1-1 is unnecessary and inappropriately placed.
Technical Specification Section 3.8 is modified to ensure appropriate refueling operation requirements are placed on the Reactor Building purge system.and the Reactor Building Stack radiation monitor. Table 3.5.1-1 is designed to apply only during reactor startup and power operation.
Adding reference to Reactor Building equalization isolation in Table 3.5.1-1, item 9 is necessary to establish conditions on Reactor Building equalization operations during reactor power operations.
A new operator action statement is added to Table 3.5.1-1, Process Instrumentation, item 9, column'(C) to address purging and equalization in relation to high-range Reactor Building area monitor operability during reactor operation and provide consistency with Technical Specification 3.6.7, 3.6.8, and Table 3.5.5-1. The Minimum Channels Operable requirement in Table 3.5.1-1, column (B) is increased from 1 to 2 in accordt.nce with the NUREG-0737 Standard Technical Specifications (Generic Letter 83-37 dated November 1, 1983) for the high-range Reactor Building area radiation monitors.
The Reactor Building pressure equalization valves are included in Technical Specification 3.6.8 to complement a Containment integrity requirement which ;
exists on the Reactor Building purge valves. The operability requirements of t Table 3.5.1-1 which address both purging and equalization are cross-referenced in Technical Specification 3.6.8.
PROPOSED AMENDMENT NO.'130, Revision 1 LOG NO. 649, Rev. 1 Safety Analysis PAGE 3 of 9 Operability requirements on the high-range Reactor Building area radiation monitors for purging operations during cold shutdown and refueling are inappropriately placed in Table 3.5.1-1, item 9. Technical Specification Section 3.8 is modified to place appropriate restrictions on the opereoility of the Reactor Building purge system and the. Reactor Building Stack radiation monitor during refueling operations. The changes proposed to the refueling Technical Specifications (Section 3.8) and Table 3.5.1-1 are in accordance with the B&H Standard Technical Specifications (NUREG-0103, Section 3.9.9, page 3/4 9-10) and the NUREG-0737 Technical Specifications for all PHR licensees (Generic Letter No. 83-37; NUREG-0737, item II.F.1.3, Containment High-Range Radiation Monitor).
Technical Specification 4.4.1.2.3(d) is rewritten to address the NRC j requirement of a 3-month Reactor Building pressure equalization valve leak i rate. testing surveillance interval. Technical Specification 4.4.1.2.3(e) is changed to reflect-the same 3-month surveillance requirement on the equalization valves.
The radioactive gaseous waste sample and analysis requirement of Table 4.22-1 is modified and clarified to include Reactor Building equalization operations specifically, and Reactor Building venting in general, thereby assuring all significant Reactor Building gaseous releases are properly sampled and analyzed prior to release.
For a negative Reactor Building pressure, an equalization operation will cause air outside the Reactor Building to flow into the Containment. To preclude the possibility of an unanalyzed release through the Reactor Building Stack (e.g., if the Containment pressure should shift from negative to positive during an equalization operation), a grab sample analysis of the Containment atmosphere and a release permit is required by procedure prior to initiation of equalization.
EVALUATION AND BASIS FOR SAFETY FINDINGS Systems. Subsystems. and Components Affected The purge system and pressure equalization system are affected by the proposed changes. A high-range radiation monitor (R-15044) was installed in the Reacter Building Stack to meet the NUREG-0737, Item II.F.1 requirement and an NRC condition on using the equalization valves during reactor power i operation.
Safety Functions of Affected Systems / Components The purge system consists of the Reactor Building purge air supply and exhaust units installed outside the Reactor Building, with penetration ducts, isolation valves and controls. The supply unit consists of a fan, electric heating coil, and ;;re-filter. The exhaust unit consists of a fan, pre-filter, high efficiency filter, and charcoal filter. Exhaust air is discharged to the atmosphere through the Reactor Building Stack and diluted by the addition of j
PROPOSED AMENDMENT N0. 130, Revision 1 LOG NO. 649, Rev. 1 I Safety Analysis PAGE 4 of 9 outside air. The discharge is monitored by the Reactor Building Stack monitor R-15044. The monitor activates an alarm system in the event of excessive radioactivity. On a high radiation signal from the Reactor Building Stack monitor, the Reactor Building purge fans are automatically tripped, thus terminating a purge vent operation. The fans are operated remotely from the Control Room.
The purge system is provided with motor-operated isolation valves inside the Reactor Building and pneumatically activated valves outside the Reactor Building in both the supply and discharge ducts. These valves are closed durir.g reactor operation and will open only for purging during cold shutdown or refueling. The purge valves are operated remotely from the Control Room. .
Testing of the isolation valves is accomplished each time the purge system is I operated.
The pressure equalization system provides a method for equalizing pressures between the Reactor Building interior and the outside environment. The system consists of a separate penetration to the Reactor Building interior and is connected to the purge system supply and discharge ducts outside the Reactor '.
Building. The 12-inch diameter penetration is equipped with two isolation valves, a motor-operated valve inside, and a pneumatically actuated valve ,
outside the Reactor Building. Connections to the purge supply and exhaust ducts are equipped with two check valves and one pneumatically operated '
equalizing auxiliary valve (also known as the equalization block valve). The valves function as follows:
A. Under normal operating conditions the purge isolation valves are closed, while the equalizing auxiliary valve (block valve) and the equalizing penetration isolation valves are also closed.
B. When the Reactor Building is under positive pressure, Reactor Building air is allowed to bleed gradually through the equalization valves while the Reactor Building exhaust fan is running. From the equalizing line the Reactor Building air flows to the inlet of the purge exhaust filters, then to the Reactor Building Stack and radiation monitor, and into the atmosphere.
C. When the Reactor Building is under negative pressure, the air bleeds into the purge system through the purge supply unit filters and is further conveyed into the building through the pressure equalizing line.
D. For the purging operation, the purge isolation valves are opened while all pressure equalization valves and the equalizing auxiliary valves are closed. For the mini-purge operation, the equalizing line is used to slowly purge the Reactor Building.
E. All purge and equalizing isolation valves close automatically on a SFAS signal. Also, the two safety features equalizing valves will isolate on a high Reactor Building high-range area radiation monitor signal.
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. l PROPOSED AMEN 0 MENT NO.:130. Revision 1 LOG NO. 649, Rev. 1' i Safety Analysis PAGE 5 of 9 F. - When equalization is in progress, the equalizing block' valve.will
- automatically close on a high radiation signal from the Reactor Building Stack monitor.
Effect 'on Safety Functions and- Analysis: 1 During ' cold shutdown, current' Technical . Specifications can require the purge-valves'to be closed even though the much larger personnel hatch and equipment hatch are permitted to be'open. Purging while in cold shutdown causes air.to .
l flow into the Reactor Building through the personnel and/or' equipment hatch.
Tripping the purge ~ fans and closing the purge valves would terminate airflow out of the' Reactor-' Building through the purge system, but would_'not block _the '
- air- path .out of the' Reactor' Building via: the equipment and/or' personnel hatches. Thus, the potential exists for an unmoni'ored and unfiltered release. If the purge valves are allowed to be open at 'all times = with the.
exhaust. fan running-during cold shutdown, a constant inflow of air .through the-equipment and/or. personnel hatch can be' maintained and an inadvertent airborne _
radioactive release'inside Containment would at worst be filtered and monitored through the purge system and Reactor Building Stack.' The proposed
. Technical Specification. changes involving the purge system are designed to
~ assure a monitored and filtered release path for the' Containment atmosphere is maintained when-Containment integrity is not required (i.e., cold ' shutdown).
During cold shutdown, the Reactor Building Stack radiation moriitor is-controlled by.the operability requirements of Table' 3.16-1 and 'is considered-the controlling cold shutdown monitor for purging operations. Table 3.5.1-l'-
-is designed to apply during startup and power operation. The' Accident:
' Monitoring Table 3.5.5-1 applies only for. operating modes above cold shutdown. Limitations placed on the-purge valves during cold shutdown that I are_ based on.the operability of the high-range Reactor-Building area monitors.
.are unnecessary. NRC Generic Letter No. 83-37 states that high-range Reactor-Building area radiation monitors?are not required to.be operable during cold shutdown and refueling operations'. The proposed Technical Specification changes will ensure that the appropriate cold shutdown requirements on the purge valves are in place.
During refueling periods, Technical Specification Section 3.8 governs the Reactor' Building purge system and Reactor Building Stack radiation; monitor ,
operability requirements. Technical Specification Section 3.8 is modified to ensure the Reactor Building purge system and Reactor, Building Stack radiation j monitor' operability requirements during refueling operations are consistent ;
I with NUREG-0737 and the B&H Standard Technical Specifications (NUREG-0103).
The operability requirements and corresponding actions ~ recommended in the !
above' referenced documents are incorporated in the Rancho Seco Technical Specifications in this proposed amendment. During refueling operations, if the Reactor Building purge system or the Reactor. Building. Stack radiation monitor becomes inoperable, the proposed Technical Specification changes will ,
require each purge system Reactor Building penetration to be closed.
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PROPOSED AMENDHENT'NO. 130, Revision 1 LOG NO. 649. Rev. 1 Safety Analysis PAGE 6 of 9 i
The accident analysis of USAR Chapter 14 contains no postulated cold shutdown !
accidents in the Reactor Building. The limiting USAR cold shutdown accident with regard to gaseous releases -is a fuel handling accident in the Spent Fuel Pool Building. This accident, analyzed in Chapter 14 of the USAR, bounds a similar accident in the. Reactor Building.
The Reactor Building Stack radiation monitor has a much lower setpoint than the high-range Reactor Building area radiation monitors. If a fuel handling accident should occur in -the Reactor Building during refueling, the Reactor Building stack monitor would function to terminate a release through the purge system by shutting off the purge supply and exhaust fans. The high-range Reactor Building area monitors are accident monitors designed to automatically close both the purge and equalization isolation valves to mitigate an accident which may occur at power operation. Having a high-range Reactor Building area monitor operability requirement on the purge valves during refueling is unnecessary and is unlikely to provide any additional radioactive release protection than is provided by Technical Specification Section-3.8 and the changes proposed to it.
Decreasing the leak test surveillance interval on the equalization valves from 6 months to 3 months will give greater assurance that the equalization isolation valves will provide Containment isolation under accident conditions. Decreasing the surveillance interval meets an NRC requirement for allowing equalization at power operation, as stated in the cover letter to the t
NRC's SER on operability of the 12-inch Containment equalization valves, dated December 4, 1984.
Failure Modes The changes made in this proposed amendment incorporate proper and reasonable operability requirements for a purge vent operation at cold shutdown and during refueling, and include consideration for Reactor Building equalization at power operation. In the present Technical Specifications, purge valves are required to be operable or closed during cold shutdown even though Containment integrity is not required and the much larger Reactor Building equipment and personnel hatches are pern'itted to be open. This proposed amendment would require the purge valves to be closed only when the plant is above cold shutdown (when Containment integrity is required), or operable or closed when refueling operations are under way inside Containment. The probability that radioactive gases may escape from the Reactor Building is not affected by this proposed amendment.
Reactor Building equalization is part of Rancho Seco's original Design Basis.
The USAR Chapter 14 accident analysis considers Reactor Building equalization system operation at power. The Technical Specification changes proposed provide Reactor Building equalization operating requirements which are designed to adequately control equalization operations. No new failure modes are introduced by this proposed Technical Specification change. Consistency between the various related Technical Specifications is provided by this change.
Hardware and Control Room instrumentation are not affected by this proposed Technical Specification amendment.
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PROPOSED AMENDMENT NO. 130, Revision 1 LOG NO. 649, Rev. 1 Safety Analysis PAGE 7 of 9 Summary Technical Specification changes are made which fulfill NRC requirements for allowing Reactor Building pressure equalization during power operation and provide for adequate control of Reactor Building pressure equalization during power operation. In addition, changes are made which alleviate the restrictiveness of purge valve operation during cold shutdown and maintain a controlled release path through the Containment when Containment integrity is j not required. Technical Specification Section 3.8 is modified to ensure the refueling requirements on the purge system and Reactor Building Stack radiation monitor are adequate and in conformance with the NUREG-0737 and NUREG-0103 Standard Technical Specifications. The probability that radioactive gases may escape from the Reactor Building is not affected by this proposed amendment. No new failure modes are introduced by the proposed changes.
UNREVIEHED SAFETY QUESTION DETERMINATION l
e "The probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the SAR will not be increased because. . ."
The Containment purge valves will not be required to be closed during cold shutdown when the high-range area monitors are inoperable and Containment integrity is not required. The maximum radiological condition which is analyzed and postulated to occur in the Reactor Building during cold shutdown or refueling is not expected to trip the high-range Reactor Building area radiation monitors. The Reactor Building Stack radiation monitor is the controlling cold shutdown and refueling monitor. This proposed amendment reduces the potential for an unmonitored, unfiltered release when Containment integrity is not required. The changes proposed to Technical Specification Section 3.8 control purge system operation during refueling operations in accordance with regulatory guidance.
Reactor Building pressure equalization at power operation is part of the plant's Licensing Design Basis. The USAR accident analysis considers Reactor Building pressure equalization operation.
- "The possibility for an accident or malfunction of a different type than any evaluated previously in the SAR will not be created because. . ."
The Containment purge valves are required to be closed during power operation.
When the plant is in cold shutdown and Containment integrity is not required, it is advantageous to provide a filtered and monitored pathway through the Reactor Building Stack instead of allowing a pathway through the equipment and/or personnel hatch. This proposed amendment does not reduce the actions required during startup and power operation modes, and enhances the refueling requirements provided in Technical Specification Section 3.8.
l PROPOSED AMENDMENT NO. 130, Revision 1 LOG NO. 649, Rev. 1
' Safety Analysis- PAGE 8 of 9 Reactor Building pressure equalization at power operation is part of the plant's Licensing Design Basis. The USAR accident analysis considers Reactor Building pressure equalization operation, e- "The margin of safety as defined in the basis for any technical specification is not reduced because. . ."
The proposed changes to Technical Specifications 3.5.1, 3.6.8, 3.8, 4.4.1.2.3' and 4.22 do not adversely impact the provisions stated in the bases for the affected Technical Specifications. Hinor editorial changes are made to the bases of the affected Technical Specifications.
Based on the above discussion, Proposed Amendment No.130, Revision 1 does not involve an Unreviewed Safety Question.
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PROPOSED AMENDMENT NO. 130, Revision 1 LOG NO. 649, Rev. I Safety Analysis PAGE 9 of 9 >
NO SIGNIFICANT HAZARDS CONSIDERATION The District has reviewed the proposed changes against each of the criterion of 10 CFR 50.92, and based on the discussion in the above safety analysis the District has concluded that:
- A significant increase in the probability or consequences of an accident previously evaluated in the SAR will not be created because. . .
Containment integrity will be maintained during those times when it is required by the Technical Specifications. Reactor Building pressure equalization at power operation is considered in the accident analysis of the SAR.
- The proposed amendment will not create the possibility of a new or different type of accident previously evaluated in the SAR because. . .
Requiring the purge valves to be closed during cold shutdown when the high-range Reactor Building area radiation monitors are inoperable and Containment integrity is not required allows for the possibility of an unmonitored, unfiltered release through the equipment and/or personnel hatches. Deleting this requirement will remove the possibility of an unmonitored, unfiltered release under the conditions described above. The proposed Technical Specification amendment is clearly bounded by the previous analysis which allows the equipment hatch and/or personnel hatch to be open during cold shutdown.
Providing limitations on Reactor Building pressure equalization operations will assure that the SAR accident analyses that consider equalization at power will also remain bounding for pressure equalization operations.
- The proposed amendment will not involve a significant reduction in the margin of safety because. . .
Containment integrity is maintained at all appropriate times, such as during refueling and when the reactor is above cold shutdown. The changes proposed do not compromise any of the bases for the affected Technical Specifications.
Based on the above discussion, the District concludes that the proposed changes do not constitute any significant hazard to the public, and in no way endanger the public's health and safety.
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