ML18057A628
| ML18057A628 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/07/1990 |
| From: | Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18057A629 | List: |
| References | |
| TAC-76806, NUDOCS 9012130049 | |
| Download: ML18057A628 (6) | |
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POW ERi Nii MICHlliAN'S PROliRESS Palisades Nuclear Plant:
27780 Blue Star Memorial Highway, Coven, Ml 49043 December 7, 1990 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
GB Slade General Manager TECHNICAL SPECIFICATIONS CHANGE REQUEST - SAFETY INJECTION TANK (SIT)
MINIMUM LEVEL (TAC NO. 76806) REVISION 2.
Enclosed is a revised proposed change to the Palisades Technical Specifications to reduce the required minimum boron solution level in the safety injection tanks from 186 inches to 174 inches and increase the maximum
- boron solution level from 198 inches to 200 inches. This Revision 2 supersedes Revision 1, dated November 9, 1990, adds a change to the allowed maximum SIT level and adds a surveillance requirement to check the SIT high and low level alarms.
Previous revision of this proposed change did not consider the +/- 2 inch uncertainty inherent in the SIT level alarm system.
The previously proposed minimum level of 174 inches is not changed since alarm level uncertainty can be accounted for by modifying the instrumentation.
The instrumentation for high alarm indication cannot be modified to all-0w for the uncertainty. Therefore, in consideration of the level alarm uncertainty and in view of analysis results (Attachment 3) which consider maximum level up to 202 inches, we are proposing to raise the maximum level allowed by_Jechnic~l Specifi'cations from 198 to 200 inches.
- - contains the proposed changed Technical Specification pages; is existing Technical Specifications pages marked up to show the proposed changes; Attachment 3 is a letter report from Advanced Nuclear Fuels which is used to justify our conclusion that this proposed change involves no unreviewed safety questions or significant hazards; Attachment 4 is the ANF Report, ANF 88-107, Revision 1, which is the current LOCA analysis of record; and Attachment 5 is a letter from ANF showing a comparison of calculated event times using the existing and proposed minimum SIT levels.
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The hardware to provide proposed SIT level alarms is being installed during the current refueling outage; therefore, Consumers Power Company requests approval of this proposed change before startup.
CC Administrator, Region Ill, USNRC NRC Resident Inspector - Palisades
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CONSUMERS POWER COMPANY
________ Docket-50-255--- - -
Request for Change to the Technical Specifications License DPR-20 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in the Provisional Operating License DPR-20, Docket 50-255, issued to Consumers Power Company on October 16, 1972, for the Palisades Plant be changed as described in Section I below:
I. Changes A.
Change Specification 3.3.1.b to read as follows:
"All four Safety Injection Tanks are operable and pressurized to at least 200 psig with a tank liquid level of at least 174 inches and maximum level of 200 inches with a boron concentration of at least 1720 ppm but not more than 2000 ppm."
B.
Change the fourth paragraph of Section 3.3 Basis as follows:
"The limits for the Safety Injection Tank pressure and volume assure the required amount of water injection during*an accident and are based on values used for the accident 'analyses (3,4).
The minimum 174-inch* level corresponds to a volume of 1040 ft3 and the maximum 200-inch level corresponds to a voltime of 1176 ft3."
C.
Add the following to
References:
."(3)
FSAR,- Section 14.17 (4)
Letter, H. G. Shaw (ANF) to R. J. Gerling (CPCo),
"Standard Review Plan Chapter 15,_Disposition of Events Review for Changes to Technical Specification Limits on Palisades Safety Injection Tank Liquid Levels", April 11, 1990.
D.
Add Survei 11 arice Function "c." to Item -13 on Table 4.1. 2 to require performance, at lease once per 18 months, of a functional check on the SIT high and low level alarms.
I I. Discussion The above proposed Technical Specifications change is requested to broaden the operating band of the Safety Injection Tanks (SITs).
The four SITs are used to flood the core with borated water following a depressurization of the primary coolant system. Three of the four tanks will provide sufficient coolant to recover the core following a LOCA.
This change to the SIT level range is considered necessary to reduce the risk of Technical Specifications violations made possible by periodic surveillance and correction of boron concentration.
When sampling the SITs to verify boron concentration, it is necessary to drain the tanks sufficiently to obtain an accurate sample.
While performing this 1
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task, Technical Specifications Section 3.3.2.a is in effect and limits the non:.Q_per_alDJJty __ p_L_on_e tank_to. one-hour--.---BeGause-a--- - -
---- sigififlcanr-amount of water must be drained from the tank to obt~in a representative sample, the possibility exists that proper level may not be restored within the one hour time period. This procedure places demands on the Operations staff which would be minimized if the operating band of the tanks were broadened.
The effect of the reduced minimum SIT inventory on the available suction source for Safety Injection during long term recirculation from the containment sump has been considered.
The reduction (1885 gal) in required mini mum inventory is a very sma 11 fraction of the total available inventory (approx. 380,000 gal) considering the vast inventory contribution from the four SITs and the SIRW Tank; and, therefore, will have a negligible effect on the operation of the safety injection pumps or the containment temperature and pressure response.
The boron concentration in the
_tanks will be unchanged and the slight reduction in total inventory will not have a significant effect on the sump boron concentration during the recirculation phase of the accident.
Additionally, this change will not significantly effect the time before hot leg injection is requi~ed to prevent precipitation of boron.
2 The small increase in allowable maximum inventory does not significantly effect the probability of tank overfill or the level of possible containment flooding.
When filled to the proposed new maximum level, the SITs remain qualified to applicable seismic criteria.
The proposed functional check on the SIT high and low level alarms will ensure the alarm system is operable.
III.. Analysis of No Significant Hazards Consideration Consumers Power Company finds that activities associated with this proposed Tech~ical Specifications change involve nQ ~ignificant hazards.
The following evaluation supports that fin~ing.
- 1.
Will the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Neither the probability nor the consequences of an accident previously evaluated will be significantly increased because the probability of a LOCA, the accident of concern, is independent of the liquid level in the Safety Injection Tanks (SITs) and the effect of a slightly reduced or increased total liquid volume in the SIT's was evaluated by Advanced Nuclear Fuels Corporation (ANF), the fuel vendor for the Palisades Plant.
The ANF analysis indicates that the proposed change in SIT inventory will not significantly affect the results of the current licensing basis LOCA analysis and that the current analysis remains bounding.
Because the change involves a relatively small increase in the maximum amount of water
3 stored in the SIT's, the probability of overfilling,
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events are not significantly increased.
- 2.
Will the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
- 3.
This change does not create the possibility of a new or different kind of accident from any accident previously evaluated because in-the event of a LOCA, the only type of accident involved, the entire boron solution content of the SITs is injected into the primary coolant system (PCS) when the PCS pressure is reduced below that of the SlTs and their elevation head~ Therefore, the proposed change in the liquid level required by the Technical Specifications does not change the function of the SITs nor does it affect the interface between the SITs and other Piant systems. Analysis by ANF concludes that for a large break LOCA, reduction of minimum SIT level does not change the result of the event.
Will the proposed change involve a significant reduction in the margin of safety?
-This change does not involve a significant reduction in.
the margin of safety because the peak cladding temperature (PCT) is not raised, containment pressure remains within design criteria,-and the amount of borated water for safety injection recirculation is not significantly reduced.
The SIT's are a system that has the function of discharging its entire content_ of borated water into the primary coolant system (PCS) when the PCS pressure drops below a specified amount.
This function is independent of the initial level of the SIT's~ If a wo~st case LOCA were to occur with the SIT's at the proposed minimum level, the total_ volume of coolant available for addition to tha PCS is reduced by an insignificant amount in view of the total volume of the PCS, the SIT's and the Safety Injection Refueling Water Tank (SIRWT).
Analysis shows that when the contents of the SIT's are at the proposed lower level and after a LOCA, the SIT's do not empty until after the PCT is reached and until after high pressure and low pressure safety injection are actuated.
At the time the SIT's do empty, the cladding temperature continues to decrease.
In addition, the LOCA containment analysis, which conservatively did not take credit for SIT injection, shows that peak containment pressure during this event stays below the design pressure.
4 I I I. Canel us ion
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-rhe--PaTiSades-PTa-nt-Re-view Committee has reviewed this Technical Specification Change Request and has d~termined that this change does not involve an unreviewed safety question.
Further, this change involves no significant hazards. This change has been reviewed by the Nuclear Safety Services Department.
A copy of this Technical Specification Change Request has been sent to the State of Michigan official designated to receive such Amendments to the Operating License.
CONSUMERS POWER COMPANY To the best of my knowledge, informatia*n and belief, the contents of this Technical.Specification Change Request are truthful and complete~
David nt Sworn and subscribed to before me thisJch day of De?e.ra J,C'r--1990.
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Notary Public.
c.A.Jv.flnAJ..-dA./\\ County, Michigan
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