ML20153C581

Proposed Tech Specs Re Standby Liquid Control Sys

ML20153C581
Person / Time
Site:	FitzPatrick
Issue date:	08/24/1988
From:	POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:
Shared Package
ML20153C455	List: JPN-88-045, Forwards Application for Amend to License DPR-59,changing Tech Specs as Result of Mods to Standby Liquid Control Sys to Ensure Min Flow Capacity & Boron Content Equivalent to 86 Gpm ML20153C458 ML20153C581
References
NUDOCS 8809010189
Download: ML20153C581 (14)

Text

• JAFNPP LIST OF FIGURES Figure Title Eage.

3.1-1 Manual Flow Control 47a 3.1-2 Operating Limit MCPR versus 47b 4.1-1 Graphic Aid in the Selection of an Adequate Interval Between Tests 48 4.2-1 Test Interval vs. Probability of System Unavailability 87 3.4-1 Sodium Pentaborate Solution 34.7 B-10 Atom % Enriched l Volume-Concentration Requirements 110 3.4-2 Saturation Temperature of Enriched Sodium Pentaborate l Solution 111 3.5-1~ Thermal Power and Core Flow Limits of Specifications 3.5.J.1 and 3.5.J.2 134 3.5-6 (Deleted) 135d 3.5-7 (Deleted) 135e 3.5-8 (Deleted) 135f 3.5-9 MAPLHGR Versus Planar Average Exposure Reload 4, P8DRB284L 135g 3.5-10 MAPLHGR Versus Planar Average Exposure Reloads 4 & 5, P8DRB299 135h 3.5-11 MAPLHGR Versus Planar Average Exposure Reload 6, BP8DRB299 1351 3.6-1 Reactor Vessel Pressure-Temperature Limits 163 4.6-1 Chloride Stress Corrosion Test Results at 500'F 164 6.1-1 Management Organization Chart 259 6.2-1 Plant Staff Organization -260 Amendment No. )d, f, pf, fd, 7$, }4, W, }Hf,1l v11 8809010189 880824-PDR ADOCK 05000333 P PNU

JAFNPP ,"

3.4 LIMIIING CONDITIONS FOR OPERATION 4.4 SURVEILLANCE REOUIREMENTS ,'

3.4 STANDBY LIOUID CONTROL SYSTEM 4.4 SIANDBY LIOUID CONTROL SYSTEM:

Applicability: Applicability: -

Applies to the operating status of the Standby Liquid Applies to the periodic testing requirements for the Control System. Standby Liquid Control System.

Objective: Objective To assure the availability of a system with the To verify the operability of the Standby Liquid capability to shut down the reactor and maintain the Control System.

shutdown condition without control rods.

Specifications Specification:

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

except as specified in 3.4.B below. This system need not be operable when the reactor is in the 1. At least once par month -

cold condition, all rods are fully inserted and Specification 3.3.A is met. Demineralized water shall be recycled to the-test tank. Pump minimum flow rate of 50 gpm l shall be verified against a system head of JE-1,275 psig.

2. At least once durino each operatino cycle Manually initiate the system, except the explosive valves and Amendment No.

/ 105 m._ __ _ _ _ _ _ _ _ _ . _ - --

JAFNPP .

3.4 (Cont'd) 4.4 (Cont'd) .

C. Sodium Pentaborate Solution C. Sodium Pentaborate Solution The standby liquid control solution tank shall The availability of the proper boroa bearing contain a boron bearing solution with a minimum solution shall be verified by performance of the I enrichment of 34.7 atom percent of B-10 that following tests:

satisfies the volume-concentration requirements -

of Fig. 3.4-1 at all times when the Standby 1. g least once par snonth -

Liquid Control System is required to be operable and the solution temperature including that in Boron concentration shall be' determined. In the pump suction piping shall not be less than addition, the boron concentration shall be the temperature presented in Fig. 3.4-2. Tank determined any time water or enriched sodium I heater and the heat tracing system shall be operable whenever the SLCS is required in order pentaborate is added or if the solution temperature drops below the limits specified to maintain solution temperature in accordance by Fig. 3.4-2.

with Fig. 3.4-2.

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2. M least once par day -

Solution volume and the solution temperature shall be checked.

3. M Jga_si pnca per operatino cycle -

a. The temperature and level elements shall be calibrated.

b. Enrichment of B-10 (in atom percent) shall be checked.

D. If specifications 3.4.A through C are not met, the reactor shall be in the cold condition within ~

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Amendment No.

107

JAFNPP .'

3.4 and 4.4 BASES The technical specifications assure that the minimum injecting time for the SLC Systesa is 44 A. Normal Operation minutes and maximum injection time 96 minutes, thus meeting the plant design basis. In addition

• The design objective of the Standby Liquid to meeting its original design basis, the system Control System is to bring the reactor from must also satisfy the Anticipated Transient Without Scram (ATWS) Rule, 10 CFR 50.62 paragraph full power to cold, xenon-free shutdown assuming that no control rods can be (c) (4).

inserted. To do this, the Standby Liquid Control System is designed to inject a The ATWS Rule requires a minimum flow capacity quantity of boron which produces a minimum and boron content equivalent in control capacity concentration equivalent to 660 ppm of to 86 gallons per minute of 13 weight percent natural boron in the reactor core. Six sodium pentaborate solution. The "equivalent in hundred and sixty ppm boron concentration in control ~ capacity" wording was clarified in the reactor core is required to bring the Generic Letter 85-03. Equivalence can be reactor from full pc-er to a subcritical obtained by increasing the flow, boron condition considering: concentration, or boron enrichment. For the FitzPatrick plant, the rule is met by using boron o the reactivity insertion due to temperature enriched to 34.7 atom perc9nt boron-10 and a decrease caused by changing water dentity, pumping rate of 50 gpm. The method used to show o decay of renon poisoning equivalence with 10 CFR 50.62 is described in o uncertainties and biases in the analyses and NEDE - 31096 - P-A :

o 25% margin for potentially imperfect mixing of the sodium pentaborate solution in the E/19.8 x C/13 x M251/M x O/86 21 1 reactor water.

where The design basis of the SLCS requires that injection be completed in a time period no 2 = boron enrichment = 34.7 atom %

less than 23 minutes and no greater than 125 0 = SLCS flow rate = 50 gpm minutes. The upper time limit (125 min) for M= mass of water in reactor vessel and complete injection of the sodium pentaborate recirculation system at hot rated condition solution was selected to override the rate of 491,700 lbs. for FitzPatrick plant reactivity insertion due to cooldown of the M251 = mass of water in vessel and recirculation reactor following the zenon poison peak. T'a e system at hot rated condition (628,300 lower time limit (23 min) is bo;;O un the Ibs.) for 251 - inch diameter vessel' plant need to allow adequate mixing, so the boron C= sodium pentaborate solution concentration does not circulate in uneven concentrations (weight percent) greater than or equal to that could cause local power fluctuations. 10 percent Amendment No. 34",

108

JAFNPP ,

ATWS requirements are satisfied at all The relief valves in the Stindby Liquid Control .

concentrations above 10 weight percent for a System protect the tystem piping and positive ,

minimum enrichment of 34.7 atom percent of B-10. displacement pumps, ehich are nominally designed for 1,500 psig, from overpressure. The pressure Figure 3.4-1 shows the permissible region of relief valves discharge back to the standby operation on a sodium pentaborate solution volume liquid control pump suction line, versus concentration graph. This curve was developed for 34.7% enriched B-10 and a pumping B. Operation _with Inoperable Components rate of 50 gpm. Each point on this curve provides a minimum of 660 ppm of equivalent Only one of two standby liquid control pumping natural boron in the reactor vessel upon circuits is needed for operation. If one circuit injection of SLC solution. At a solution volume is inoperable, there is no immediate threat to of 2200 gallons, a weight concentration of 13% shutdown capability, aid reactor operation may sodium pentaborate, enriched to 34.7% boron-10 is continue during repairs. Assurance that the needed to meet shutdown requirements. The remaining system will perform its function and maximum storage volume of the solution is 4780 that reliability is good is obtained by gallons which is the net overflow volume in the demonstrating pump operation in the operable SLC tank. circuit at least daily.

Boron concentration, isotopic enrichment of C. Sodium Pentaborate Solution boron-10, solution temperature, and volume are checked on a frequency adequate to assure a high To guard against precipitation, the solution, reliability of operation of the system should it including that in the pump suction piping, is ever be required. Experience with pump kept at least 10*F above saturation temperature.

operability indicates that monthly testing is Figure 3.4-2 shows the saturation temperature adequate to detect if failures have occurred. including 100F margin as a function of sodium pentaborate solution concentration. Tank heater The only pr actical time to test the Standby and heat tracing system are provided to assure Liquid Control System is during a refueling compliance with this requirement. The set points outage and by initiation from local stations. for the automatic actuation of the tank heater Components of the system are checked periodically and heat tracing system are established based on as described above and make a functional test of the solution concentration. Temperature and the entire system on a frequency of more than liquid level alarms for the system annunciate in once each refueling outage unnecessary. A test the control room. Pump operability is checked on of explosive charges from one manufacturing batch a frequency to assure a high reliability of is made to assure that the charges are operation of the system should it ever be satisfactory. A continuous check of the firing required.

circuit continuity is provided by pilot lights in the control room.

Amendment No. 38', 7 109 '

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__ _ - - __ _ _ _ /

JAFNPP .'

Once the solution is prepared, boron concentration -

does not vary, unless more enriched sodium penta- .

borate or more water is added. Level indications and alarms indicate whether the solution volume has changed which might indicate a possible '

solution concentration change. The test interval has been established considering these factors.

Boron enrichment (B-10 atom percent) does not vary with the addition of enriched sodium pentaborate material or water to the SLC tank provided 34.7% enriched (B-10 atom percent) is added. Therefore, a check once per operating cycle is adequate to ensure proper enrichment.

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ATTACHMENT II TO JPN SAFETY EVALUATION FOR PROPOSED TECHNICAL SPECIFICATION CHANGES REGARDING STANDBY LIOUID CONTROL SYSTEM (JPTS-88-08)-

NEW YORK POWER AUTHORITY i JAMES A. FITZPATRICK NUCLEAR POWER PLANT DOCKET NO. 50-333 DPR-59 l

Attachment II to JPN SAFETY EVALUATION Page 1 of 5 I. DESCRIPTION OF THE PROPOSED CHANGEE The proposed changes to the James A. FitzPatrick Technical Specifications revise Sections 3.4 and 4.4 and their associated Bases:

(a) On page vii, the titles of Figures 3.4-1 and-3.4-2.are revised.

(b) On page 105, in Specification 4.4.A.1, the flow rate is changed from 39 to 50 gpm.

(c) On page 107, in Specification 3.4.C, the phrase, "with a minimum enrichment of 34.7 atom percent of B-10," is added. Also, the phrase "tank heaters" is replaced with "tank heater and the heat tracing system."

(d) On page 107, in Specification 4.4.C.1, the word "boron" is replaced with "enriched sodium pentaborate."

(e) Specification 4.4.C.3 is revised on page 107. It reads:

3. At least once ner operatina cycle -

a. The temperature and level elements shall be calibrated.

b. Enrichment of B-10 (in atom percent) shall be checked.

(f) On pages 108, 109, and new page 109a, the Bases have been rewritten for clarity and to reflect the change from 600 ppm of natural boron to 660 ppm of equivalent natural boron and the changes resulting from application of Anticipated Transient Without Scram (ATHS) requirements.

(g) On page 110, replace Fig. 3.4-1, "Sodium Pentaborate Solution Volume - Concentration Requirements" with new Fig. 3.4-1, "Sodium pentaborate Solution 34.7 Atom %

Enriched Volume Concentration Requirements." This figure is revised to indicate the changes in the region required for volume and concentration of enriched sodium pentaborate solution.

(h) On page 111, replace Fig. 3.4-2, "Saturation Temperature of Sodium pentaborate Solution", with new Fig. 3.4-2, "Saturation Temperature of Enriched Sodium Pentaborate Solution (Includes 100F Margin)."

Attachment II to JPN SAFETY EVALUATION Page 2 of 5 II. PURPOSE OF THE PROPOSED CHANGE 10 CFR 50.62 paragraph (c) (4) requires that:

"Each boiling water reactor must have a standby liquid control system (SLCS) with a minimum flow capacity and boron content equivalent in control capacity to 86 gallons per minute of 13 weight percent sodium pentaborate solution."

This requirement is intended to provide prompt injection '

of negative reactivity in the event of an ATWS event.

This equivalency will be obtained at the FitzPatrick plant by changing to a SLC solution which is enriched to 34.7 atom percent boron - 10 (B10).

In addition to meeting 10 CFR 50.62 requirements, to permit an increase in reload enrichment and energy content in future core design reloads, the final in-vessel boron concentration following injection of standby liquid control solution is being increased from 600 ppm of natural boron to 660 ppm of equivalent natural boron.

III. IMPACT OF THE PROPOSED CHANGE The ATWS Rule (10 CFR 50.62) requires that the SLCS has a minimum equivalent control capacity of 86 gallons per minute (gpm) of 13 weight percent sodium pentaborate solution.

NRC Generic Letter 85-03 clarifies "equivalent control capacity." It can be provided by increasing flow rate, boron concentration, or B-10 enrichment. The 86 gallons per minute and 13 weight percent sodium pentaborate were values used in NEDE-24222, "Assessment of BWR Mitigation of ATWS, Volumes I and II," December 1979, for BWR/4,-

BWR/5, and BWR/6 plants with a 251 inch vessel inside diameter. Different values are applicable to the Fitzpatrick plant because inside vessel diameter is 218 inches. The existing SLCS is required to pump 39 gpm into the reactor vessel but has a tested capability of 52 gpm with either of the two pumps. The new required flow rate will be 50 gpm minimum. The existing tank solution is typically 13 weight percent sodium pentaborate with natural boron. Natural boron is 19.8 atom percent B-10 isotope. B-10 is the isotope which provides the necessary negative reactivity to shutdown the reactor if the SLCS

l

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Attachment II to JPN )

SAFETY EVALUATION Page 3 of 5 )

is actuated. For the Fitzpatrick plant the rule will be met by increasing B-10 enrichment and taking credit for 50 gpm pumping capacity. The modified tank solution will typically contain an 11.5 weight percent sodium pentaborate made up from boron enriched to 34.7 atom percent B-10 isotope. That this provides the required "equivalent control capacity" was verified by a calculation performed in accordance with NRC's "Safety Evaluation of Topical Report (NEDE-31096-P)

"Anticipated Transient Without Scram; Response to ATWS Rule, 10 CFR 50.62" which was attached to NRC letter to NYPA, "ATWS Rule (10 CFR 50.62): Plant Specific Reviews", dated January 8, 1987. This change increases the negative reactivity insertion of the SLCS.

Furthermore, the final in-vessel boron concentration following injection of standby liquid control solution is being increased from 600 ppm of natural boron to 660 ppm of equivalent. natural boron. The additional margin permits increases in reload enrichment and energy content in future reload core designs. Actual shutdown margin for reload cores is determined during the reload core design and analysis process and must meet appropriate design and licensing criteria.

The existing (unmodified) SLCS typically has a 13 weight percent sodium pentaborate solution which requires heat tracing to ensure that the solution temperature stays above-the boron precipitation temperature of 580F. The new tank solution will be typically 11.5 weight percent concentration which has a precipitation temperature of 520F, Since the minimum room temperature for the SLCS is 650F, this concentration reduces the need for the tank heater and the heat tracing system, thus increasing system reliability and enhancing the overall safety for the system. .The setpoints for the tank heater and heat tracing system will be reduced consistent with the new precipitation temperature.

The SLCS, including the SLC Tank, is a seismic Category I design. The change in tank contents will not affect that design. The new solution is slightly less dense due to the reduction in sodium pentaborate weight percent concentration.

This difference is in the conservative direction but is small and not really significant.

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Attachment II-to JPN SAFETY EVALUATION Page 4 of 5 IV. EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATION Operation of the FitzPatrick plant in accordance with the proposed amendment would not involve a significant hazards consideration as stated in 10 CFR 50.92, since it would not:

1.- Involve a significant increase in the probability or consequences of an accident previously evaluated. The change involves an increase in B-10 enrichment in the solution in the SLC Tank and an increase in required pumping capacity. Although the modification involves decreasing the concentration of sodium pentaborate in the SLC Tank, the increased enrichment of B-10 and increased solution pumping rate-result in an'overall increase in the injection rate of B-10 isotope ~into the reactor vessel. As a result of the increased amount of B-10 isotope in the SLC tank, the final in-vessel boron concentration following injection of SLC solution is being increased from 600 ppm of natural boron to 660 ppm of equivalent natural boron.

The increased boron concentration in the reactor vessel will allow future core reloads to utilize higher energy content fuel without decreasing present shutdown margin. Furthermore, operation of the SLCS with the proposed changes will merely provide a backup to other safety related systems in accordance with 10-CFR 50.62 requirements.- Also, the reduced need for a-tank heater and the heat tracing system contributes to the overall reliability of the system.

2. Create the possibility of a new or different kind of accident from any accident previously evaluated. The ATWS changes proposed and the accompanying plant modifications only serve as backups to already ,

existing safety-related systems. The proposed changes '

will ensure that the SLCS is maintained such that it is capable of fulfilling the operability requirements l of 10 CFR 50.62. As stated above, the proposed changes increase the shutdown margin in the unlikely 1

j event that SLCS should be needed to shut down the reactor. No new or different kinds of accidents result from improving the effectiveness of the SLCS.

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v Attachment II to JPN SAFETY EVALUATION Page 5 of 5

3. Involve a significant reduction in a margin of safety. On the contrary, this change increases the negative reactivity inserted by the SLCS, and, therefore, enhances the safety margin for the plant.

The proposed changes are in accordance with the requirements of 10 CFR 50.62, and provide additional assurance that the SLCS is capable of safely shutting down the plant in the unlikely event that its use is required. SLCS operability does not decrease the margin of safety since it serves as backup to other safety-related systems.

V. IMPLEMEuTATION OF THE PROPOSED CHANGE Implementation of the proposed changes will not impact the ALARA or Fire Protection programs at the FitzPatrick plant, nor will the changes impact the environment.

VI. CONCLUSlQE The ch6nge, as proposed, does not constitute an unreviewed safety question as defined in 10 CFR 50.59. That is, it:

a. will not change the probability nor the consequences of an accident or malfunction of equipment important to safety as previously evaluated in the Safety Analysis Report;

b. will not increase the possibility of an accident or malfunction of a type different from any previously evaluated in the Safety Analysis Report;

c. will not reduce the margin of safety as defined in the basis for any Technical Specification;

d. does not constitute an unreviewed safety question; and

e. involves no significant hazards consideration, as defined in 10 CFR 50.92.

VII. REFERENCES

1. James A. FitzPatrf.ck Nuclear Power Plant Updated l Final Safety Analysis Report, Sections 3.9.3, 3.9.4, 14.5.11.

2. James A. Fitzpatrick Nuclear Power Plant Safety Evaluation Report (SER).

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