ML20214T634

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Proposed Tech Specs Reflecting Mods to Standby Liquid Control Sys,Per 10CFR50.62(c)(4) Requirements Re ATWS
ML20214T634
Person / Time
Site: Pilgrim
Issue date: 05/29/1987
From:
BOSTON EDISON CO.
To:
Shared Package
ML20214T629 List:
References
NUDOCS 8706100360
Download: ML20214T634 (11)
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Text

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ATTACHMENT 2 4

j REVISED TECHNICAL SPECIFICATION PAGES

P. #95 1
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  1. 99 (deleted)
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i Oog62 888 G70529 P 05000293 ~

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--,a n LlHITING CONDITIONS FOR OPERATION SURVEILLANCE RE0llIREMENTS 3.4 STANDBY LIOUID CONTROL SYSTEM 4.4 STANDBY LIOUID CONTROL SYSTEM Aeolicability: Acolicability:

Applies to the operating status Applies to the surveillance of the Standby Liquid Control requirements of the Standby System.

Liquid Control System.

Objective: Obiective:

To assure the availability of a To verify the operability of the

' system with the capability to Standby Liquid Control System.

shutdown the reactor and maintain the shutdown condition without the use of control rods.

Soecification: SDecification:

A. Normal System Availability 1

A. Normal System Availability

1. During periods when fuel is in the reactor and prior to The operability of the Standby startup from a cold Liquid Control System shall be verified by the performance of condition, the Standby Liquid the following tests:

Control System shall be operable, except as specified 1. At least once per month j

in 3.4.8 below. This system each pump loop shall be need not be operable when the i

reactor is in the Cold functionally tested by j

Shutdown Condition, all recirculating operable control rods are demineralized water to the fully inserted and test tank.

Specif.ication 3.3.A is met. 2. At least once during each

, operating cycle:

.; a. Check that the system

relief valves trip full open at pressures t

less than 1800 psig, and reseat on a falling pressure t greater than 1275 psig,

b. Manually initiate the system, except explosive valves.

Pump boron solution through the recirculation path and back to the Standby Liquid Control Solution Tank. Check l that each pump flow j rate meets or exceeds 39 GPM against a system head c' 1275 psig.

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.. LIM 1 TING CONDITIONS FOR OPERATION SURVEILLANCE REOUIREMENTS 3.4 STANDBY LIOUID CONTROL SYSTEM 4.4 STANDBY LIOUID CONTROL SYSTEM

c. Manually initiate one of the Standby Liquid Control System loops and pump demineralized water into the reactor vessel.

This test checks explosion of the charge associated with the tested loop, proper operation of the valves, and pump operability. The replacement charges to be installed will be selected from the same manufactured batch as the tested charge.

d. Both systems, 4 including both explosive valves, shall be tested in the course of two operating cycles.

B. Ooeration with Inonerable B. Surveillance with Inonerable Comoonents: Components:

1. From and after the date 1. When a component is found that a redundant to be inoperable, its component is made or redundant component shall found to be inoperable, be demonstrated to be Specification 3.4.A.1 operable immediately and shall be considered daily thereafter until the fulfilled and continued inoperable component is r operation permitted repaired. -

provided thtt the cos,ponent is returned to an operable condttien vithin seven days.

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LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.4 STANDBY LIQUID CONTROL SYSTEM 4.4 STANOBY LIQUID CONTROL SYSTEM )

C. Sodium Pentaborate Solution C. Sodium Pentaborate Solution  !

At all times when the Standby The following tests shall be Liquid Control System is performed to verify the required to be operable the availability of the Liquid following conditions shall be Control Solution:

met:

1. Volume: Check at least
1. The net volume - once per day, concentration of the Liquid Control Solution 2. Temperature: Check at in the liquid control least once per day.

tank shall be maintained as required in Figure 3. Concentration: Check at 3.4-1. least once per month.

Also check concentration

2. The temperature of the anytime water or boron is 11guld control solution added to the solution, or shall be maintained above the solution temperature 48'F. If the solution is at or below 48'F.

temperature falls to or below 48'F, the system 4. Enrichment: Check B' will be flow tested to enrichment level by test verify aflow path. anytime boron is added to the solution and during

3. The enrichment of the each refueling outage.

11guld control solution Enrichment analyses shall shall be maintained at a be received within 30 days B'* lsotope enrichment of test performance. If exceeding 54.5 atom not received within 30 percent. days, see Table 6.9.1 for reporting requirements.

D. There are two operational considerations associated with the Standby Liquid Control sodium pentaborate solution requirements. The first consideration involves sodium pentaborate concentration / volume requirements. The second consideration involves B

isotopic enrichment. The related Limiting Conditions for Operation are delineated below:

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. 3.4 STANDBY CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.4 STANDBY LIQUID CONTROL SYSTEM 4.4 STANDBY LIQUID CONTROL SYSTEM D.1 If specification 3.4.A, B, or C.1 or C.2 cannot be met, the reactor shall be placed in a Cold Shutdown Condition with all operable control rods fully inserted within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

D.2 If the enrichment requirements of specification 3.4.C.3 are not met, a check shall be made to ensure that sodium pentaborate solution meets the original design criteria by comparing the enrichment, concentration and volume to established criteria. If the sodium pentaborate solution does not meet the original design criteria, the reactor shall be placed in a Cold Shutdown Condition with all operable control rods fully inserted l within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

D.3 If the sodium pentaborate solution meets the original design criteria, but the enrichment requirements of specification 3.4.C.3 are not met, bring the B' isotopic enrichment to greater than 54.5 atom percent within seven days from the time of receipt of the enrichment report. If after this time period the enrichment requirements of specification 3.4.C.3 are still not met, submit a report to the NRC within seven days and advise them of plans to bring the solution up to a demonstratable 54.5 atom percent B isotopic enrichment.

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Tank Overflow 10 Line of Minimum Sodium 9.5 -- /Pentaborate Weight 9.22 g 8.82 Region of Required Volume -

\ Concentration (Entire Zone) 8.5 -- 8.42

% Sodium Pentaborate l Minimum Minimum Boron Concentration by 8 Concentration Bio Isotope Weight 7.5 .

Line Enrichment

> 54.5 Atom Percent 7

6.5 -- 2068 4696 I  ;

6 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 V. Net Tank Votume (Gallons)

Figure 3.4 - 1 Sodium Pentaborate Solution Volume and Concentration Requirements Amendment No. Page 98

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BASES:

3.4 & 4.4 STANDBY LIQUID CONTROL SYSTEM A. The requirements for SLC capability to shut down the reactor are identified via the station Nuclear Safety Operational Analysis (Appendix G to the FSAR, Special Event 45). If no more than one operable control rod is withdrawn, the basic shutdown reactivity requirement for the core is satisfied and the Standby Liquid Control system is not required. Thus, the basic reactivity requirement for the core is the primary determinant of when the standby liquid control system is required. The design objective of the standby liquid control system is to provide the capability of bringing the reactor from full power to a cold, xenon-free shutdown condition assuming that none of the withdrawn control rods can be inserted. To meet this objective, the Standby Liquid Control system is designed to inject a quantity of boron that produces a concentration equivalent to 700 ppm of natural boron in the reactor core. The 700 ppm equivalent concentration in the reactor core is required to bring the reactor from full power to a three percent 6 k subtritical condition, considering the hot to cold reactivity difference, xenon poisoning etc. The system will inject this boron solution in less than 125 minutes. The maximum time requirement for inserting the boron solution was selected to override the rate of reactivity insertion caused by cooldown of the reactor following the xenon poison peak.

The Str.ndby Liquid Control system is also required to meet 10CFR5J.62 (Requirements for Reduction of Risk from Anticipated Transients Without Scram (ATHS) Events for Light-Water-Cooled Nuclear Power Plants). The Standby Liquid Control system must have the equivalent control capacity (injection rate) of 86 gpm at 13 percent by wt. natural sodium pentaborate for a 251" diameter reactor pressure vessel in order to satisfy 10CFR50.62 requirements. This corresponds to an equivalent control capacity (injection rate) of 66 gpm at 13 percent by wt.

natural sodium pentaborate solution for the PNPS reactor pressure vessel diameter of 218". This equivalency requirement is fulfilled by a combination of concentration, B' enrichment and flow rate of sodium pentaborate solution. A minimum 8.427.

concentration and 54.57. enrichment of B'" isotope at a 39 GPM pump flow rate satisfies the ATHS Rule (10CFR 50.62) equivalency requirement.

Because the concentration / volume curve has been revised to reflect the increased B'" isotopic enrichment, an additional requirement has been added to evaluate the solution's capability to meet the original design shutdown criteria whenever the B'" enrichment requirement is not met.

Experience with pump operability indicates that the monthly test, in combination with the tests during each operating cycle, is sufficient to maintain pump performance. The only practical time to fully test the liquid control system is during a refueling outage. Various components of the system are individually tested periodically, thus making more frequent testing of the entire system unnecessary.

Amendment No. 100

BASES:

l 3.4 & 4.4 STANDBY LIOUID CONTROL SYSTEM (Cont'd) l l The minimum limitation on the relief valve setting is intended to prevent the loss of sodium pentaborate solution via the lifting of a relief valve at too low a pressure. The upper limit on the relief valve settings provides system protection from overpressure.

B. Only one of the two standby liquid control pumping loops is needed for operating the system. One inoperable pumping circuit does not immediately threaten the shutdown capability, and reactor operation can continue while the circuit is being repaired. Assurance that the remaining system will perform its intended function and that the long term average availability i

of the system is not reduced is obtained for a one out of two system by an allowable equipment out of service time of one third of the normal surveillance frequency. This method determines an equipment out of service time of ten days.

Additional conservatism is introduced by reducing the allowable out of service time to seven days, and by increased testing of the operable redundant component.

C. The quantity of B' stored in the Standby Liquid Control System Storage Tank is sufficient to bring the concentration of B'" in the reactor to the point where the reactor will be shutdown and to provide a minimum 25 percent margin beyond the amount needed to shutdown the reactor to allow for possible Imperfect mixing of the chemical solution in the reactor water.

Level indication and alarm indicate whether the solution volume has changed, which might indicate a possible solution concentration change. Test intervals for level monitoring have been established in consideration of these factors.

Temperature and liquid level alarms for the system are annunciated in the control room.

The solution shall be kept at least 10*F above the maximum saturation temperature to guard against boron precipitation.

Minimum solution temperature is 48'F. This is 10*F above the saturation temperature for the maximum allowed sodium pentaborate concentration of 9.22 Ht. Percent.

Each parameter (concentration, pump flow rate, and enrichment) is tested at an interval consistent with the potential for that parameter to vary and also to assure proper equipment performance. Enrichment testing is required when material is received and when chemical addition occurs since change cannot occur by any process other than the addition of new chemicals to the Standby Liquid Control solution tank.

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TABLE 6.9.1 Area Reference Submittal Date

a. Secondary Containment 4.7.C.c Upon completion of Leak Rate Testing (1) each test (2)

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b. (Deleted)
c. (Deleted)
d. Gross Gaseous Release 4.8.B. Ten days after the 0.05 Cl/sec for 48 release occurs Hours
e. Standby Liquid Control 3.4.C.3 Fourteen days after solution enrichment out receipt of a non-of specification complying enrichment report or lack of receipt of such a report within the required thirty days, if enrichment compilance cannot be achieved within seven days.

NOTES: 1. Each integrated leak rate test of the secondary containment shall be the subject of a summary technical report. This report shall include data on the wind speed, wind direction, outside and inside temperatures during the test, concurrent reactor building pressure, and emergency ventilation flow rate. The report shall also include analyses and interpretations of those data which demonstrate compliance with the specified leak rate limits.

2. The report shall be submitted within 90 days after completion of each test. Test periods shall be based on the commercial service data as the starting point.

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