ML20011D406

Proposed Tech Specs Re Limiting Conditions for Operation for Chemical & Vol Control Sys

ML20011D406
Person / Time
Site:	Fort Calhoun
Issue date:	12/20/1989
From:	OMAHA PUBLIC POWER DISTRICT
To:
Shared Package
ML20011D403	List: ML20011D402 ML20011D405 ML20011D406
References
NUDOCS 8912270130
Download: ML20011D406 (11)

Text

. __ _

ft '

jggge:3

• 2.0 2 LIMITING-C04DITIONS'FOR OPERATION 2.2. Chemical and Volume Control System l

Acolicability Applies to the operational status of the chemical and volume control system.

Obiective To' define those conditions of the chemical and volume control system necessary to assure safe reactor operation.

Soecifications (1) When fuel is in the reactor, there shall be at least one-flow path

-to the core for boric acid injection. This flow path may be from the SIRWT, with at least 10,000 gals. available at refueling baron concentration or from a BAST which meets the requirements of Figure 2-11 for a SIRWT boron concentration at the technical specification

' limit.

(2) The reactor shall not be made critical unless all the following minimum requirements are met:

a. At least two charging pumps shall- be operable,

b. - One boric acid transfer pump shall be operable,

c. The minimum volume of borated water contained in the concentrated boric acid tank (s) is dependent on the boric acid .

storage tank (BAST) and SIRW tank boron concentrations. The minimum required volume curve is shown in Figure 2-11.

Depending on the flow paths available, this volume of borated .

water can be either the combined volume of the two BASTS, or the minimum in each BAST, or can be contained in a specific BAST. The BAST is defined as the tank, gravity feed valve, pump and associated piping. The ambient temperaturc of the boric acid tank solution CH-11A and CH-118 shall mee+ the temperature requirements of Figure 2-12.

d. System piping and valves shall be operable such that one of the following four conditions will be satisfied. If piping or valves become inoperable and a condition change is required, six (6) hours are allowed when changing from one condition listed below to another condition' listed below.

dl. The required BAST volume of Figure 2-11 can be combined between CH-11A and CH-llB when both tanks are operable.

d2. When LCV-218-3 is inoperable or the SIRWT volume is below Technical Specification minimum, then each BAST must be l operable and contain the required volume of Figure 2-11 l corresponding to the requirements of the SIRWT Technical  ;

Specification boron concentration.  !

- 2-17 8912270130 891220 PDR ADOCK 05000.285 P._ _. _ ppg _ __ ,, _

e y i

\

'250 LIMITING CONDITIONS FOR OPERATION 2.2= Chemical and Volume _ Control System (Continued) d3. - When BAST CH-llB is inoperable, then BAST CH-llA must be.

operable and contain the required volume of Figure 2-11 and LCV-218-3 must be operable. l d4. When BAST CH-11A is inoperable, then BAST CH-11B must be

_ operable and contain the required volume of Figure 2 '

and LCV-218-3 must be operable,

e. Both level.' instruments on the concentrated boric acid tanks shall be operable.

(3) Modification of Minimum Requirements During power operation, the minimum requirements may be modified to allow any one of the following conditions to exist at any one time.

'if the system is not restored to meet the minimum requirements within-the time period specified, the reactor will be placed in a hot shutdown condition in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. If the minimum requirements are not satisfied within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, a co?d shutdown shall be initiated.

a. -One of the operable charging pumps may be removed- from service provided.two charging pumps are operable within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. '

b. Both boric acid pumps may be out of service for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided that both BASTS meet the requirements of. Figure 2-11. 3

c. One level instrument channel on each inservice concentrated boric acid tank may be out of service for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Basis The chemical.

coolant systemand volume boron control l( ystem inventory. provides This is control normally of the reactor accomplished by using any one of the three charging pumps in series with one of the two boric acid pumps. An alternate method of boration will be to use-the charging pumps directly from the SIRW-storage tank. A third method will be to depressurize and use the safety injection pumps. There are two sources of borated water available for injection through three different paths.

(1) The boric acid pumps can deliver the concentrated boric acid tank ,

contents (2.5-4.5 weight percent concentration of boric acid) to the i charging pumps. The tanks are located above the charging pumps so that the boric acid will flow by gravity without being pumped.

(2) The safety injection pumps can take suction from the SIRW tank which i maintains a boric acid concentration greater than the required i refueling concentration.

(3) The charging pumps can take their suctions by gravity from either the boric acid tanks or the SIRW tank.

5 Amendment No. M //J N 2-18

P4 MIED,,

t

~ 2.0 LIMITING CONDITIONS FOR OPERATION 2.2 .GF3mical and Volume Control System (Continued)

Each concentrated boric acid tank containing 2.5-4.5 weight-percent boric !

acid has sufficient boron to bring the plant to a cold shutdown .

condition. Boric acid pumps are each of sufficient capacity to feed all three charging pumps at their maximum capacity.

The concentrated boric' acid storage tank is sized for 2.5-4.5 weight percent bcric acid solution and is capable of storing solution up to 4.5 -

weight percent solution. All components of the system are capable of maintaining 4.5 weight perecnt solution. The elevation of the I concentrated boric acid tank is sufficiently above the charging pump suction so as to provide adequate gravity flow to the charging pumps.

Figure 2-1? contains a'10'F bias to account for temperature measurement uncertainty. -The operation of an inservice BAST, in accordance with 2.2.

(3).c, with only an alarm channel is permitted.

The SIRW tank contents are sufficient +o borate the reactor coolant in order to reach cold shutdown at any time during core life.

The limits on component operability and the time periods for inoperability were selected on the basis of the redundancy indicated above and engineering judgment.-

References (1) USAR, Section 9.2 2-19 .

I 1

7,' ...

. l

'S-

7pggB. ,

+

100 ,

90 4 g 80 W- N\

I '70 '

s a y x' x -

- N

e. 50 'N N N 40 '

w N '

N N

\ 3

\

.m g 30 x w s NXx g -

N 2;

E 20 N x '

x

'; \

. , 'J 1 ,

10 0 ' '

2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 - 4.5 STORED BAST CONC (WT % BORIC ACID)

A 1800 PPM e 1900 PPM + 2000 PPM

• 2150 PPM + 2300 PPM IN SIRWT IN SIRWT IN S;RWT IN SIRWT IN SIRWT FORT CALHOUN MIN BAST LEVEL OMAHA PUBLIC POWER DISTRICT FIGURE vs STOFIED BAST CONCENTRATION FORT CALHOUN STATION-UNIT 1 2-11

^

• - :.* . -?.. >

f)

.. i

~11 10 /

l l [' )

!; /

8

/

NOT ACCEPTABLE l

• /

~

-6 u /

/

N 5 --

4 /

~ / ACCEPTABLE

_ / .

2 -

1 0 ' ' ' ' ' '

30 40 50 60 70 80 90 100 110 120 130 140 TEMPERATURE (DEGREES F)

~

OMAHA PUBLIC POWER DISTRICT FIGURE BORIC ACID SOLUBILITY IN WATER FORT CALHOUN STATION-UNIT 1 2-t?

-- ,- -.. ~ .7 p

• .I Q T "

r; ;m TABI.E 3-2 (cont.inued) -

!.117!II:lt1 F E!:QUE:!CIES FOR Cl!ECES, CA!.TIPjnTIO IS A!!D TESTII!G OP

"lGillEE!ED SAFim FEATilliF3 , I:;5RGEITATIO:I AllD COI:TiiOLS Survei1 lance ,

Cira nne ! Dese r i pt. i on Func t. i ' n Freqocncy Surve111ance 14e Lod Ih. (continued) b. Calibrate R b. Enown pressure and differential pressure applied. to pressure and level sensors.

15 Boric Acid "'ank Level a. Check L a. Compare two independent sensors.

b. Test R b. Pump tank below low-level -

alarm point to verify switch

,/

operation, y e. Calibrate R- c. Known differential pressure applied to_ level y sensora. At least three points in indicator range vill be obtained-high,' middle-of-range, and low s'near alarm set-point).

16. Boric Acid lient Tracing a. Check D a. Observe temperature devices for proper readings.

17 Steam Generator Lov a. Check S a. Compare four independent pres-

,g Pressure Signal (SGLS) sure indientions.

> :r

1. S' jS b. Test  !!(2) b. Simulated signal.

>o i

y c. Calibrate R e. Known pressure applied to sen-1- sors to verify i. rip points, logic 4 geration,iblock permissive, auto reset and valve closures.

1 g

p

. -, w,.ima s M.-.m_. m_.m.--wh j-n ad %t.a.mti..- _.'- ..a-]E<

rra,.---- --

__y g'n - 2 .h.-p ams-h. w. .. m.,-- _ _ .a

.gj c _ .

..hl2Oftf5Eb..

TABLE 3-2.~ (contirmed)

MINDuf FRBOUENCIES FOR OIECES, CATT%"TWS AND TESTDC OF DGINEERED SAFEIY FEMURES, INST 1DIENIATION AND CONIBOIS Surveillance diarnel Description Ibnctim Freauency Surveillance Method

14. (continued) b. Calibrate R b. K.un prt.m ard differential ptwunwe j a g lied to pream ne and level sensors.

15. Boric Acid Tank Invel a. Q1eck D' a. Wre two indic, Rimas.

b. Test R b. Punp tank below low-level a] arm point to verify switd1 operation.

c. Calibrate R c. Rhown differential pressure applied to level' 1

sensors. At least three points in indicator range will be obtained-high, miMle-of-range, and low (near alarm set-point).

Y Boric Acid Tank Tenperature O 16. a. dieck D a. Observe teobne devices for proper Indication Imdings.

17. Steam Generator Iow Pressure 4. dieck S a. Ocupare four lime:L pressure Signal (SGIE) indications.

b. Test M(2) b. Sin 11ated signal.

c. Calibrate R c. Known pres-sare a@ lied to sensors to verify tri;, points, logic operation, block pav=Mive, auto reset and valve closures.

e 6

e 1

.+ - < - - - -_ . _ . _ _ _ _ _ . . . - _ _ . - - _ - - _ _ _ _ - - - - . . <

. - . .. - .-. .,_n.-

~~

g #.' g

.-8 --g 8 .J '.

' 9' .

. . e t 3

6' <

f [

4 .

1

' ') ?

14 s b

=,4 6

?

o ATTACHMENT B i

4 '

t y

b 1

T 4

.,w - ,-r- - -- ----- - e

t y. *,

• 1.~ Basis for No Sionificant Hazards Considerations The proposed change to Section 2.2, Chemical and Volume Control System will revise Technical S 2.2.(3).d, 2 J (3)pecifications

.e and 2.2.(3).f,2.2.(2).c, add Figure 2.2.(2).d, 2-11, and2.2.(2).e, amend the2.2.(3).c, basis and reference.

The specifications define: (1) the volume and concentration of boric acid to be maintained in the Safet Acid Storage ianks (BAST)for y injection cooldownRefueling Water of the plant; and Tank (SIRWT)

(2) the and Boric flow paths from the BAST to the reactor coolant system during the various modes of plant operation. .

. Technical Specification Section 2.2.(2).c and 2.2.(2).d specify the minimum tank levels and system flow paths to ensure that an adequate source of boric acid-is available to provide a 4.0% delta k/k shutdown margin during a plar.t cooldown. The flow path available will determine if the required volume of borated water can be either the combined volume of the two BASTS, or the minimum in each BAST, or can be contained in a specific BALT. The most conservative cooldown requirements have been utilized in tne determination of "

the minimum BAST level along with application of appropriate biases and uncertainties for level indication, vortex generation, and auxiliary spray u:,ago. Single failure requirements with operator action have been identified

to ensure the ability of the boric acid system to perform its safety function t

of plant cooldown. Credit is not taken in any of the safety analyses including the LOCA analysis for concentrated boric acid injection to mitigate an accident or anti-ipated operational occurrence.

Technical Specification Section 2.2.(2).e is deleted as heat tracing of the boric acid system is no longer required to prevent precipitation of boric acid from solution. The reduction of the concentration range to De maintained in one or both BASTS is specified in Figure'2-11. The new Figure 2-11 will represent the minimum required volume at a given concentration of boric acid to be maintained. The proposed change will allow this volume to be maintained as a combined volume in either or both of the BASTS. The concentration is in the range of approximv ely 2.5 to 4.5 weight percent boric acid. Figure 2-11 incorporates four curves which represent the minimum boric acid vclume required from BASTS for a given SIRWT concentratien. The minimum ambient temperature in -

the auxiliary building is sufficient to prevent boric acid precipitation.

Technical Specification Section 2.2.(3).c and 2.2.(3).d are deleted since they specify the minimum system configuration requirements for the equipment during operation. The system flow paths have been established in Section 2.2.(2).d to ensure suffi::ient boric acid is available for injection to the RCS. The proposed change will require that both the gravity feed and the boric acid transfer pumps be operable. There is one gravity feed path and one boric acid pump path from each BAST. If the combined volume of boric acid required is contained as a combined volume between the two BASTS, then the proposed change will require both gravity feed paths and both boric acid transfer pump paths be operable. If the minimum boric acid requirements are being satisfied by one BAST, then the proposed change will require only the gravity feed path and boric acid pump path from that tank to be operable.

v . .

3.. .; q Y TechnicalSpecificationSection2.2.(3).eisdeletedasitspecifiesthe minimum heat tracing operability. The reduction of the concentration range to i be maintained in one or both BASTS is specified in Figure 2-11. The new Figure 2-11 will represent the minimum required volume at a given concentration of

, boric acid to be maintained. The proposed change will allow this volume to be maintained as a combined volume in either or both of the BASTS. The concentration is in the range of approximately 2.5 to 4.5 weight percent boric acid. Figure 2-4A incorporates four curves which represent the minimum boric acid volume required from BASTS for a given SIRWT concentration. The minimum ambient temperature in the auxiliary building is sufficient to prevent boric acid precipitation.

Technical Specification Section 2.2.(3).f has been changed to 2.2.(3).c for consistency in numbering for the section.

-Figure 2-11 specifies the minimum required boric acid tank volume as a function-of concentration to maintain the shutdown margin of 4.0% delta k/k at all times during a cooldown to 210'F. To set the minimum BAST volume corresponding to the various BAST and SIRWT concentrations a parametric analysis was completed to calculate the required boric acid concentration to maintain the 4.0% delta k/k shutdown margin for vario:!s BAST and SIRWT level versus RCS temperature.

The basis of Technical Specification Section 2.2 has been amended to reflect the proposed change as described in the justification and discussion evaluation. This is consistent with the proposed changes described above.

The reference "FSAR, Section 9.2" has been changed to "USAR, Section 9.2" as the FSAR has been replaced by the USAR. This is an administrative change and does not have any impact on the Technical Specification.

The proposed amendment to the Technical Specification does not involve a significant-hazards consideration because the operation of the Fort Calhoun Station in accordance with this amendment would not:

(1) Involve a significant increase in the probability of occurrence or consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report. The boric acid system is not utilized in the safety analysis report to mitigate the consequences of an accident or malfunction. From the standpoint of reactivity control, the BAST and SIRWT concentrations ensure that a minimum of 4.0% shutdown margin is maintained during a cooldown from hot standby to cold shutdown as described in the safe shutdown scenario described below.

The plant is in hot standby and has been held at hot zero power conditions with the most reactive rod stuck in the full out position for 23.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> following a power reduction from 100% to 0%. (TheXenonpeak after shutdown will have decayed back to the 100% power equilibrium Xenon level. Further Xenon deca cure during the plant cooldown.)yNo will add was credit positive takenreactivity to the for the negative reactivity effects of the Xenon concentration peak following the power reductica. At 23.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> offsite power is lost and the plant goes into natural circulation. All non-safety grade plant equipment and components are lost. During the natural circulation cooldown the RCS average temperature initially rises 25'F due to decay heat in the core.

The initial temperature at the start of the cooldown is 557'F.

. .. 1, ,

e .

Approximately 0.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> later, at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the' operators commence a cooldowntocoldshutdown(210*F). The proposed volume and flow path requirem3nts will ensure that the plant can be brought to cold shutdown conditions assuming letdown is unavailable, in conjunction with the loss of offsite power, and assuming the limiting single failure.' Therefore, the proposed change does not increase the probability or consequences of an accident or malfunction of equipment important to safety.

(2) Create the possibility for an accident or malfunction of a new or different type than previously evaluated in the safety analysis report,.

The proposed change does not physically alter the configuration of the plant and no new or different mode of operation has been implemented.

Therefore, the possibility of an accident or malfunction of a new or different type'than any previously evaluated in the safety analysis report.

(3) Involve a signif'icant reduction in the margin of safety as defined in the basis for any Technical Specification. The proposed change

. maintains the basis of the safety enalysis. In addition, the more restrictive requirements of boron flow paths effectively ensure that the plant cc.n be brought to cold shutdown in the limiting sate shutdown scenario. Therefore, the margin of safety as defined in the basis for the Technical Specification is not reduced.

Based on the above considerations, OPPD does not believe that this amendment involves a significant hazards consideration as defined by 10CFR50.92 and the proposed changes will not result in a condition which significantly alters the impact of the. station on the environment. Thus, the proposed changes meet-the eligibility criteria for categorical exclusion set forth in 10CFR51.22(e)(9) and pursuant to 10CFR51.22(b) no environmental impact or environmental assessment need be prepared.

q.  %; 3 6 ' e

,, BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION

'In the Matter of ' ) .

i

)

8 Omaha Public Power District Docket No. 50-285 b' (Fort Calhoun Station Unit No. 1) i . APPLICATION FOR AMENDMENT  !

0F <

OPERATING LICENSE  !

t

(

Pursuant to Section -50.90 of the regulations of the U. S. Nuclear Regulatory Commission ("the Commission"),' Omaha Public Power District, holder of f acility Operating License No. DPR _40, herewith requests.that the. Technical Specifications set forth in Appendix A to that License be amended to reflect changes to' the Limiting Conditions for Operations for the Chemical and Volume Control System.

The proposed changes in Technical Specifications are discussed in Attachment A to this Application. A discussion, Justification and no Significant Hazards Consideration Analysis, which demonstrates that the proposed changes do not involve significant hazards considerations is appended in Attachment B. The proposed changes in specifications would not authorize

,, any change in the types or any increase in the amounts of . effluents or a change in 'the authorized power level of the facility.

WHEREFORE, Applicant respectfully requests that the definitions and Sections 2 and 3 of Appendix A to Facility Operating License No. DPR-40 be

. amended in the form attached hereto as Attachment A.

-$T:6 2 2. 7 [ l. 2 P [

pg .

m i , i ", :,

k

.g.

-j A copy of this Application, including its' attachments, has been submitted I to the Director - Nebraska State Division of Radiological Health, as required by 10 CFR 50.91.

OMAHA PUBLIC POWER DISTRICT  !

By e dbionManrger Nuclear. Operations l

I  ;

Subscribed and sworn to before me this 2/)r# day of December,1989.

Y bnK Notary Public d

GENERhl h01hRY St.1*r of g;:ra$ga J.T. CLEASON N  % CCW!L IJP July 2E 12 9

.-._4