ML20236X428
| ML20236X428 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 12/04/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236X426 | List: |
| References | |
| NUDOCS 8712090184 | |
| Download: ML20236X428 (7) | |
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[g UNITED STATES 4
g NUCLEAR REGULATORY COMMISSION g
- j WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 38 TO FACILITY OPERATIFG LICENSE NO. NPF-29 MISSISSIPPI POWER & LIGHT COM.PANY SYSTEM ENERGY RESOURCES, INC.
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SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION GRAND GULF NUCLEAR STATION, UNIT 1
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i DOCKET NO. 50-416 l
1.0 INTRODUCTION
1 By letter dated July 6,1987, as superseded October 23, 1987, and supplemented November 19, 1987, System Energy Resources, Inc.
(SERI or the licensee), requested an amendment to Facility Operating License No. NPF-29 for the Grand Gulf Nuclear Station, Unit 1.
The l;l proposed amendment would provide one time exceptions to Section 3.0.4 in the Technical Specifications (TS) for use during the second refueling outage. The exceptions would allow entry into certain operational conditions without meeting the Limiting Conditions for Operation (LC01,
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provided.the requirements of associated action statements are met. The j
action statements require alternate methods of decay heat removal and j
reactor coolant circulation when the residual heat removal (RHR) system or ECCS subsystems required by the LCOs are inoperable.
The licensee supplemented its application by letter dated November 19, 1987, in response to staff's request for additional information. This
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November 19, 1987 submittal, which provided a more detailed description and analysis of alternate methods for residual heat removal and reactor coolant circulation, did not alter the staff's proposed no significant hazards determination as noticed in the _ Federal Register on November 4, 1987 (52 FR 4?363).
2.0 EVALUATION Section 3.0.4 in the Technical Specifications states:
3.0.4 Entry into an OPERATIONAL CONDITION or other specified J
condition shall not be made unless the conditions for the Limiting Condition for Operation are met without reliance on provisions contained in the ACTION requirements. This I
provision shall not prevent passage through or to OPERATIONAL CONDITIONS as required to comply with ACTION requirements.
Exceptions to these requirements are stated in the individual Specifications.
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The proposed changes to the TS would provide exceptions to Specification 4
3.0.4 during the second refueling outage for the following TS.
The.first proposed change will add a new Action "c" and "**" footnote to Specification 3.4.9.2, Reactor Coolant System - Cold Shutdown, to state that the provisions:of Specification 3.0.4 are not applicable and that the change is applicable until startup from the second refueling outage.
The second proposed change will add a statement to Action "a" of Specification 3.5.2, Emergency Core Cooling System (ECCS) - Shutdown, to state that the provisions of Specification 3.0.4 are not applicable.
A "f" footnote will also be added to state that the change is applicable until startup from the second refueling outage.
The third proposed change will add statements to Actions "b," "c," and "d" of Specification 3.7.1.1, Standby Service Water (SSW) System, to state that the provisions of Specification 3.0.4 are not applicable.
The change to Action "b" will only be applicable for entry into Operational I
Condition 4.
Also added is a "*" footnote to state that the change is applicable-until startup from the second refueling outage.
The fourth and fifth proposed changes will add new Actions "c".to Specifications 3.9.11.1 and 3.9.11.2, Refueling Operations - Residual Heat Removal (RHR) and Coolant Circulation, to state that the provisions of Specification 3.0.4 are not applicable. Also added are "#" footnotes to state that the changes are applicable until startup from the second refueling outage.
During the second refueling outage, presently scheduled to extend from November 6, 1987 through January 8, 1988, various combinations of ECCS systems and RHR trains will be made inoperable to perform required maintenance, surveillance testing and inspections and to make design changes. These activities will require the plant to enter action statements for shutdown cooling and ECCS at various times during the outage.
These proposed changes will provide one-time exceptions to Specification 3.0.4 for these specifications for the second refueling outage only, to allow the plant to enter Operational Conditions 4 and 5 and to allow reactor head tensioning, reactor cavity flooding and reactor cavity draining while in these action statements. With the present TS, these ECCS and RHR maintenance and testing activities would have to be interrupted during head tensioning and reactor cavity flooding and draining in order to make the ECCS and RHR operable as required by the LC0 of the TS. After completing the head tensioning, reactor cavity flooding and reactor cavity draining, the ECCS and RHR systems would again be made inoperable and the action statements entered to complete maintenance and testing ~ activities.
In addition to the TS requirements, the licensee's outage policy is to
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l maintain at least one ECCS system and one fuel pool cooling and cleanup l
system functional at all times. The term " functional" means that the system can perform its intended safety function (i.e., ECCS can inject water into the reactor at rated flow and decay heat removal systems can perform at rated capacity), although some manual actions may be required, such as closing breakers or realigning valves. Also, at least one shutdown cooling mode train of RHR will be functional through-out the outage unless required maintenance or testing activities preclude this. The diesel generator associated with each of the above systems is also required to be functional.
In accordance with this outage policy, the current outage schedule (which will utilize these proposed TS changes) provides for separate outage intervals for the two RHR shutdown cooling trains, ensuring that the time interval when both trains are inoperable is minimized and is scheduled at a time when the reactor cavity is flooded.
By letter dated November 19, 1987, the licensee has described how the proposed exceptions would be used in the second refueling outage and the alternate methods of decay heat remeval and reactor coolant circu-lation which would be used to fulfill action statement requirements. The dates used are based on the current schedule for the second refueling outage and are subject to change.
During the period from November 20 through December 8, 1987, inclusive, Specification 3.9.11.1 would be applicable and would require one RHR shutdown cooling train to be operable and in operation.
Both shutdown cooling trains are scheduled to be inoperable, requiring entry into the action statements of Specification 3.9.11.1.
One action statement requires an alternate method of decay heat removal and the other action statement requires an alternate reactor coolant circulation method.
The alternate method of decay heat removal scheduled is the fuel pool cooling and cleanup (FPCCU) system and the reactor water cleanup (RWCU) system used concurrently. Alternate coolant circulation is achieved by the RWCU system.
For the period from December 8, 1987 through December 23, 1987, inclusive, two RHR shutdown cooling trains are required to be operable with one in operation (Specification 3.9.11.2).
Over this period RHR train B is scheduled to be operable and in operation and RHR train A is scheduled to be inoperable. The RWCU system and the Control Rod Drive (CRD) System (concurrently) would be utilized as an alternate decay beat removal method, as required by the action state-ment of Specification 3.9.11.2.
Exceptions to Specification 3.0.4 are scheduled to be utilized on December 8 and December 22, 1987. On December 8, SERI has scheduled draining of the reactor cavity water level below the 22 feet 8 inch level to decontaminate the cavity, remove vibration instrumentation and replace the reactor vessel head. This requires movement from Specification 3.9.11.1 to Specification 3.9.11.2.
The Limiting Conditions for Operation are not met without relying on the action statement of Specification 3.9.11.2 requiring an exception to j
Specification 3.0.4.
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3 Specification 3.5.2 in conjunction with Specification 3.0.4, requires two ECCS systems to be operable in order to drain the reactor cavity below 22 feet 8 inches. Low pressure coolant injection (LPCI)
Train B is required to be made inoperable after the cavity draining in order to perform maintenance on a valve that cannot be serviced with the cavity flooded. The proposed Specification 3.0.4 exception to Specification 3.5.2 is required to prevent the evolution of declaring LPCI Train B operable to allow cavity draining, then declaring LPCI Train B inoperable to permit valve maintenance.
This valve maintenance will not affect RHR Train B since the valve requiring maintenance can be isolated from the RHR system.
' Additionally, during the cavity draining on December 8, standby service water (SSW) Train A is scheduled to be inoperable for acid cleaning, flushing, and inspection.
Specification 3.9.11.2 requires two RHR trains to be operable, which in turn regrires two SSW systems to be operable by Specification 3.7.1.1.
The Limiting Condition for Operation of Specification 3.7.1.1 will not be met for the inoperable RHR Train described above (Specification 3.9.11.2).
This 3.0.4 exception will be used at this time, since SSW B will be the only operable SSW 1 cop.
A Specification 3.0.4 exception is scheduled for use on December 22.
On this date, reactor head studs are scheduled to be tensioned causing entry into Operational Condition 4.
Specification 3.4.9.2 requires two RHR trains to be operable in Operational Condition 4.
The RHR Train A is scheduled to be inoperable at that time.
The November 19, 1987 letter also provided the results of analyses to demonstrate the adequacy of these alternate methods for decay heat removal and reactor coolant circulation. Decay heat as a function of time after shutdown was computed for the fuel in the reactor and the fuel in the spent fuel pool.
Fuel will be located in the spent fuel pool and the reactor vessel during the periods that alternate methods of decay heat removal will be utilized. When using alternate decay heat removal systems, irradiated fuel is not scheduled to be located in the upper containment pool.
The licensee's analyses show that the heat removal capacities of the scheduled alternate methods of decay heat removal exceed the decay heat loads in the spent fuel pool and the reactor core at the times after reactor shutdown when they would be used.
The reactor water cleanup (RWCU) system is used as an alternate reactor coolant circulation system (drawing water from recirculation lines and injecting it into the feedwater line). The RWCU system takes suction and discharges coolant at the same location as the RHR system when it is operated in the shutdown-cooling mode.
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The licensee has considered steps that could be taken in the event of.
failure of the alternate methods of decay heat removal.
In case of a loss of offsite power, the fuel pool cooling and cleanup (FPCCU) system may be restored to service for cooling spent fuel in the spent fuel pool and the reactor when flooded to 22 feet 8 inches or above, because SERI has' scheduled the emergency diesel generator associated with the one required ECCS and FPCCU train to be functional.
If heat loads are such that FPCCU cannot remove decay heat sufficiently to maintain coolant temperature less than 140*F a " feed and bleed" type decay heat removal-method would be utilized, injecting water into the cavity or reactor and draining excess water to the suppression pool.
If offsite power is available, normal pool makeup.from the condensate and refueling water system or from makeup water treatment system can be used.
In case of a loss'of off site power, control rod drive pumps, ECCS pumps, ECCS jockey pumps, and/or the SSW pumps can be used.
In case of a station blackout, procedures are established for providing water from the diesel. driven fire pump to the pools and/or reactor vessel. Drain paths can be established through normal cavity drains, RWCU, RHR, or other means.- In addition, during the period of November 30.through December 8, RHR Train B will be undergoing tests and surveillance which involve system lineups associated with those tests. These lineups preclude the use of RHR Train B as an operable shutdown cooling subsystem; however, if necessary, RHR Train B can be lined up for shutdown cooling and put into operation (although until the tests and surveillance are completed, it could not be declared operable).
Two tests to demonstrate alternate decay heat removal methods are scheduled for the two reactor cavity levels prior to the use of these methods. The tests will be run with an RHR train secured but operable. The first test will demonstrate that the FPCCU system with the RWCU system can cool the fuel remaining in the vessel and the irradiated fuel in the spent fuel pool, with the reactor head off and upper containment pool flooded up to or above 22 feet 8 inches. This test will utilize the system operating instructions for FPCCU system and RWCU system. Temperature monitors in the spent fuel pool, the reactor water cleanup suction, the reactor head drain and recirculation loop, the upper containment fuel pool, the fuel pool cooling drain tank, and the fuel pool heat exchanger outlet will be utilized for acceptance of the test results. Acceptance will be based on determination that the temperature measured by all of the above temperature monitors is decreasing or stable, and below 140*F.
i The second test.will utilize the RWCU and CRD systems as an alternate decay heat removal method with the reactor head off, the reactor cavity drained, and irradiated fuel moved to the spent fuel pool. This test will also utilize the system operating instructions for the RWCU and CRD systems to demonstrate the capability to remove decay heat from the reactor vessel.
Temperature monitors for the reactor water clean-up suction, the reactor vessel from bottom head drain and the recirculating loop will be utilized
for acceptance of the test results. Acceptance will oe based on a determination that the temperature measured by these temperature monitors is decreasing or stable and below 140*F.
Alternate methods of decay heat removal have been previously demonstrated at Grand Gulf Nuclear Station (GGNS).
The calculated results regarding alternate decay heat removal should bound the test results of alternate decay heat removal. However, the purpose of the calculation is to indicate the point during the outage at which the proposed alternate is capable of removing the required decay heat.
Satisfactory test results will prove the alternate method of decay heat removal capacity before it is put into use.
The NRC staff has reviewed the licensee's submittals requesting ore-time exceptions to Specification 3.0.4 during the second refueling outage. The licensee has planned the outage to minimize the time when the ECCS systems, the RHR trains and the FPCCU trains will be inoperable because of required maintenance or testing. When these systems or trains are inoperable, the licensee will maintain them functional, as much as possible, so they can be used with some manual actions involved in realigning valves or closing breakers. The licensee has analyzed the performance of alternate methods of decay heat removal (RWCU, CRD, and FPCCU systems) to determine when during the outage they have the capability to maintain reactor coolant average temperature and the spent fuel pool temperature less than 140*F, as required by the TS. Tests of heat removal capability will be run for these alternate methods of decay heat removal prior to their use in the l
refueling outage, to demonstrate that the TS limiting temperature of
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140'F can be achieved.
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The use of the proposed exceptions to TS Section 3.0.4 in the manner proposed l
by the licensee will not change the safety margins for shutdown cooling and coolant injection, which would be available without the use of the l
exceptions.
Further, the licensee has planned the outage to utilize the ECCS, the RHR and the FPCCU systems as much as possible, with due consideration for necessary maintenance. Accordingly, the staff concludes that the one-time exceptions to TS Section 3.0.4 proposed by the licensee for use during the 1
second refueling outage at GGNS Unit 1 are acceptable.
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3.0 ENVIRONMENTAL CONSIDERATION
This amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released off site; and that there is no significant increase in individual or cumulative occupational radiation exposure. The Comission has previously issued a proposed finding that this amendment involves no significant hazards consideration, and there has been no public coment on such finding.
Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no i
i environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The Commission made a proposed determination that this amendment involves no significant hazards consideration, which was published in the Federal Register (52 FR 42363) on November 4, 1987, and consulted with the l
State of Mississippi. No public coments or requests for hearing were received and the State of Mississippi did not have any come.ts.
The staff 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, and (2) such activities will be conducted in compliance with the Comission's regulations and the issuance of this amendment will not be inimical to the comon defense and the security, or to the health and safety of the public.
Principal Contributor:
L. L.Kintner Dated: December 4, 1987 1
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