ML18347A523

Transmitting Proposed Technical Specifications, Secondary Water Monitoring and Maximum Primary Coolant Radioactivity

ML18347A523
Person / Time
Site:	Palisades
Issue date:	04/03/1976
From:	Bixel D Consumers Power Co
To:	Purple R Office of Nuclear Reactor Regulation
References
Download: ML18347A523 (12)

Text

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• consumers Power company General Offices: 212 West Michigan Avenue,.Jackson, Michigan 49201

• Area Code 517 788-0550 April 3, 1976

• Director of Nuclear Reactor Regulat Att:

Mr Robert A. PUrple, Chief Operating Reactor Branch No 1 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255, LICENSE DPR PALISADES PLANT. -

PROPOSED TECHNICAL SPECIFICATIONS, SECONDARY WATER MONITORING AND-MAXIMUM PRIMARY COOLANT RADIOACTIVITY By letters* dated January 30, 1976 and March 9, 1976 we have prepared changes

.to the Palisades Plant Technical Specifications related to the steam generators.

Following discussions with members of the Commission staff, we have concluded that additional specification changes are appropriate.

This letter transmits a new specification on secondary water chemistry and a revised specification on primary coolant radioactivity.

David A. Bixel Assistant Nuclear Licensing Administrator CC:

JGKeppler, USNRC

CONSUMERS POWER COMPANY Docket No 50~255 Request for Change to the Technical Specifications License No DPR-20 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in Provisional Operating License No DPR-20, Docket No 50-255, issued to Consumers Power Company on October 16, 1972, be changed as follows:

I.

Changes A.

Add new Section 3.19 as follows:

113.19 Secondary Water Chemistry Requirements Applicability:

Applies to the secondary water chemistry of the steam generator blowdowri during power operation (generator synchronized).

Objective:

• To minimize potential steam generator tube degradation caused by contamination of the secondary coolant.

Specification:

3.19.1 Steam generator water chemistry shall be maintained in accordance with Table 3.19.1 except as specified below.

3.19.2 The limits for pH and sodium specified in Table 3.19.l shall be achieved within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of synchronization of the unit. If these limits are not established within this time, the reactor shall be brought to hot standby condition within an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, 3,19,3 During operation, other than that specified in 3.19.2, the limits for pH and sodium may exceed those specified in Table 3.19.1 for a period of up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If these limits are not restored, the reactor shall be placed in hot standby within an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

11 3.19.4 The limit for specific conductivity specified in Table 3.19.1 shall be achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of synchronization of the unit. If this limit is not established within this time period, then the reactor shall be brought to the hot standby condition within an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

3.19.5 During operation, other than that specified in 3.19.4, the limit for specific conductivity specified ih Table 3.19.1 may be exceeded for a period of up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If these limites are not restored, the reactor shall be placed in hot standby within an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />."

TABLE 3.19.1 Secondary Water Chemistry Contr9l Parameters Sample Point Each Steam Generator Blowdown Basis Specific Conductivity

@ 25°C

7. 0 mnho/cm Sodium 8.0-9.5 0.460 Ppm Contamination of the steam generator secondary coolant can cause potential tube degradation and impair tube integrity, Generally, the most severe contamination results from condenser inleakage impurities that may accum-ulate on the secondary side of the steam generator.

Some of these impu-rities may be caustic forming.

High concentrations of free caustic deposited in the steam generator, or on the Inconal -600 tubes, can lead to the potential for intergranular stress corrosion cracking, Monitoring of the steam generator blowdown total conductivity is an effective means of detecting condenser inleakage.

The conductivity of the steam generator blowdown will indicate when increased blowdown is required to remove the accumulation of potentially caustic forming impurities and the scale forming solids in the steam generator.

Moni-toring the steam generator blowdown sodium concentration will provide adequate insurance that potential caustic forming contaminates in the steam generator are maintained within accepted limits.

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"Monitoring the secondary water within the Technical Specifications limits.will control the potential accumulation of corrosive impurities in the steam generator and minimize tube degradation."

B.

Add new part to Section 4.14 as follows:

"4.14.4 Secondary water chemistry parameters shall be determined to be within the limits of Table 3.19.1 during power operation.

Analysis shall be conducted in accordance with the following schedule.

1.

Daily for pH and specific conductivity.

2.

Three times per week for sodium."

C.

Change Section 3.1.4 in its entirety to read as follows:

"3.1.4 Maximum Primary Coolant Radioactivity Specification:

3.1.4.1 Except as specified below the specific activity of iodine isotopes in the primary coolant shall be limited to < 4.3

µCi/gram 'dose equivalent I-131.'

'Dose equivalent I-131' shall be that concentration of I-131 (µCi/gram) which alone would produce the same thyroid dose as the quantity and isotopic mixture of I-131, I-132, I-133, I-134 and I-135 actually present.

The thyroid dose conversion factors used for this calculation shall be those listed in Table III of TlD-14844, ;'Calculation of Distance Factors for Power and Test Reactor Sites.'

3.1.4.2 With the specific activity of the primary coolant < 4.3

µCi/gram 'dose equivalent I-131' but less than 86 µCi/gram

'dose equivalent I-131' operation may continue for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided that operation under these circumstances shall not exceed 36 days per calendar year.

3.1.4.3 With the specific activity of the primary coolant> 4.3 µCi/gram

'dose equivalent I-131' for more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> during one con-tinuous time interval or exceeding 86 µCi/gram 'dose equivalent I-131, an appropriate power reduction shall be made or be in hot standby within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

3

"3.1.4.4 With the specific activity of the primary coolant > 4.3

µC:i./gram dose equivalent I-131' perform the sampling and analysis requirements of Item 1.3.a of Table 4.2.l until the specific activity of the primary coolant is restored Basis to within its limits.

A reportable occurrence shall be prepared and submitted to the Commission pursuant to Speci-fication 6.9.2.b.

This report shall contain the results of the specific activity analysis together with the following information:

1.

2.

3.

4.

5.

'Reactor power histc>ry starting 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the first sample in which the limit was exceeded, Fuel burnup by core regio'n, Clean-up flow history starting 4a hours prior to the first sample in which the limit was exceeded, History of degassing operation, if any, starting 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the first sample in which the limit was exceeded, and The time duration when the specific activity of the primary coolant exceeded 4.3 iiCi/gram 'dose equivalent I-131. I The maximum specified primary coolant radioactivity is intended to be that which would result from operation with 0.68% fuel defects. (l)

Radiation shielding and the radioactive waste disposal systems were designed to operate with 1% defects( 2 ) and, therefore, with the speci-fied maximum radioactivity, these considerations are not limiting.

The specified limit provides protection to the public against the potential release of primary coolant radioactivity to the atmosphere as demonstrated by the following analysis of a steam generator tube rupture accident. (3 )

References

1.

FSAR, Table ll-1.

2.

FSAR, Section ll.1.1.

3.. FSAR, Section 14.15.

4

. "The maximum potential dose at the site boundary due to this accident, based upon an upper limit calculation, is larger and hence more limiting than the dose that would result from one year of operation with the maximum Unidentified leakage from the primary coolant system allowable by Specification 3,1.5.a.

Rupture of a steam generator tube would cause a reactor and turbine trip and allow primary coolant radioactivity to enter the secondary system.

Calculations indicate that about 9.5% of the total coolant activity at 1% failed fuel is I-131. (l)

For purposes of the accident dose calculation, however, it is conser-vatively assumed that 10% of the iodines are released from that portion of the primary coolant leaking into the secondary system.

Radioactivity would be released until the operator could reduce the primary coolant system pressure below the set point of the secondary system relief valves and could isolate the faulty steam generator.

The accident is considered to be a double-ended break of a single steam generator tube followed by initiation of system cooldown within 30 minutes after the tube break and complete isolation of both steam generators within 3,6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

During this period, approximately one~third of the total primary coolant and its associated radioactivity is.released to the secondary system. ( 3 )

The limiting dose for this case would be due to the iodine because of its low MPC in air, for which the inhalation dose at the site boundary is computed as follows:

Dose (Rem) = C

• V

• B(t)

• X/Q

• DCF

• 10-l Where C = Primary coolant 11dose equivalent I-131' activity (4.3 µCi/gram).

V =Primary coolant volume released (l/3x310 m3 = 103 m3 ).

B(t) =Breathing rate (3.47 x 10-4 m3/s).

X/Q = 2.6 x 10-4 s/m3, 0-2 hour dispersion coefficient at site boundary (677 m) using a building wake coefficient of 1/2.

References Ibid.

5

• "DCF = 1.48x106 Rem/Ci I-131 inhaled.

10-l = Fraction of iodine released to atmosphere.

The 4.3 µCi/gram of 'dose equivalent I-131' activity results in less than 6.0 Rem thyroid dose at the site boundary.

The limitations on the specific activity of the primary coolant ensure that the resulting 2-hour doses at the site boundary will not exceed an appropriately sinall fraction of Part 100 limits following a steam gener-

' ator tube rupture accident.

The statement permitting power operation to continue for limited time periods with the primary coolant's specific activity 4.3 µCi/gram 'dose equivalent I-131,' but less than 86 µCi/gram dose equivalent I-131,' ac-commodates possible iodine spiking phenomenon which may occur following changes in thermal power.

Operation with specific activity levels ex-ceeding 4.3 µCi/gram 'dose equivalent I-131' but less than 86 µCi/gram

'dose equivalent I-131' must be restricted to no more than 10 percent of the unit's yearly operating time since these activity levels could increase the 2-hour thyroid dose at the site boundary by a factor of up to 20 following a postulated steam generator tube rupture.

The 525°F temperature in the specification corresponds to a saturation pressure of 848 psia which is below the 985 psig minimum set point of the secondary system relief valves.

Therefore, potential primary to secondary leakage at temperatures below 525°F could be contained within the steam generator by closing the steam line isolation valve on the defective steam generator.

The surveillance requirements provide adequate assurance that excessive specific activity levels in the primary coolant will be detected in sufficient time to take corrective action.

Information obtained on iodine spiking will be used to assess the parameters associated with spiking phenomena.

A reduction in frequency of isotopic analyses fol-lowing power changes m_ay be permissible if justified by the data obtained. 1' 6

D~

Change Table 4.2.1 as follows:

,]_,

Ch?-nge heading to read:

"Table 4,2.1 Cont."

2.

Delete Item 1 and footnotes (1) and (2) from Page 4-14.

3.

Add new Page 4.13b (Table 4.2.1) as follows:

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Test 1.0 PRIMARY COOLANT SAMPLES 1.1 Gross Activity Determination

1. 2 Isotopic Analysis f'or Dose Equivalent I-131 Concentration 1.3 Isotopic Analysis for Iodine Including I-131, I-133 and I-135 1.4 Chemistry (Cl and o2 )

1.5 Chemistry (Fluoride)

TABLE 4.2.1 MINIMUM FREQUENCY OF SAMPLING TESTS Frequency 3 times per 7 days with a maxi-mum time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> between samples.

1 per 14 days.

a) Once per 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, whenever the dose equivalent I-131 ex-ceeds 4.3 µCi/gram, and b) One sample between 2 and 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> following a thermal power change exceeding 15%

of the rated thermal power within a 1-hour period.

3 times/week.

Monthly.

Modes in Which Sample And Analysis Required Tavg greater than 525°F.

Power operation.

(1)

Tavg greater than 525°F and at thermal power levels above 25% rated power.

Average primary coolant temperature greater than 210°F.

Average primary coolant temperature greater than 210°F.

(1)

Until the specific activity of the primary coolant system is restored within its limits.

FSAR Section Reference None None None None None None

E.

Change the basis of Section 4.2 by replacing the second paragraph "The radiochemical..* turnover rate" with the following:

"The 'dose equivalent.I-131 1 activity of the primary coolant shall be determined to be within the limits by performance of the sampling and analysis program of Table 4.2.1.

The analysis for 'dose equivalent

.I-131 1 will also provide an adequate method of conservatively estimating the whole body dose which could result from the rupture of a steam generator tube."

II. Discussion A & B.

During an evaluation made to determine the most appropriate limits for detecting the presence of condenser water leakage, condensate conductivity was considered.

This review determined that steam generator total conductivity would provide leak detection sensitivity at less than one gallon per minute and that condensate conductivity would not.

This difference is due to the concentrating effect of the steam generators.

We have thus concluded that measurement of steam generator blowdown conductivity is the most appropriate ap-proach to detecting condenser leakage.

Measurement of free hydroxide was also considered and we have con-cluded that the most appropriate method of limiting this parameter is by placing a limit on sodium.

This limit is equivalent to a free hydrodie limit of 1.0 ppm.

The limits proposed are considered appropriate for the Technical Specifications as limiting condition of operation while continuing to allow for some operational flexibility.

Plant operating procedures are much more comprehensive and conservative than those proposed as limiting conditions of qperation.

This method of control will enhance successful long-term operation without unduly restricting plant operation.

C, D & E.

The previously used limit of 75/Eresults in a total body dose of 0.5 Rem as follows:

9

Reference Dose (Rem) =

Where:

E =

A =

v =

X/Q =

1/2 [E

• A

• V/3

• X/Q * (3.7 x 1010 ) * (1.33 x l0-11 )]

Average energy of betas and gannnas per disintegration (MeV).

Primary coolant activity (75/E Ci/m3 -MeV).

Primary coolant volume (310 m3); V/3 is volume of coolant released.

2.6 x 10-4 s/m3, 0-2 hour dispersion coefficient of the site boundary (677 m) using an appropriate building wake coefficient.

3.7 x lOlO dps/Ci 1.33 x 10-ll Rem/MeV/m3 The resulting whole-body dose is 0.5 Rem.

However, since I-131 is about 9.5%,of the total coolant activity(l),

the total coolant activity would be about 31 µCi/gram when the I-131 level is high enough to give 6 Rem to the thyroid.

In order to achieve 0.5 Rem total body dose, 75/E = 31, or E = 2.42.

Since no nuclide mix within the primary coolant is capable of an E as high as 2.42 MeV, iodine dose will be limiting in all instances.

Limiting the dose to 6 Rem to the thyroid is derived by applying 10 CFR 100.ll(a)(l) ratio of thyroid to total body maximum permis-sible dose.

This dose is also essentially identical to that implied in the present Technical Specifications.

Tritium measurements have been deleted as there are no requirements for these measurements.

Fluoride contamination of the primary system ip not likely to occur from contaminated makeup water, or work associated with the primary system when it is.open.

Fluoride levels in the makeup source (lake water) are about a factor of 10 below those for chloride and other sources of fluoride appear to be small compared to that for chloride.

We conclude that a monthly sampling frequency for fluoride will be adequate.

(1)

FSAR, Table 11-1.

10

III.. Conclusion BaseQ on the foregoing, the Palisades Plant Review Committee concluded that this change does not involve an unreviewed safety question.

Time restraints have not permitted a review by the Safety and Audit Review Board.

This review will be conducted and we will advise you should any of these proposed changes be deemed inappropriate.

CONSUMERS POWER COMPANY Date:

April 5, 1976 Sworn and subscribed to before me this 5th day of April 1976.

Syl~J B. Bafi, Notary Public Jackson County, Michigan My commission expires May 18, 1976.

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