ML20214M861

Proposed Tech Specs,Changing Section 3/4 11.2, Gaseous Effluents,Dose Rate, to Provide More Accurate Indication of Activity Inside Containment

ML20214M861
Person / Time
Site:	Sequoyah
Issue date:	05/22/1987
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20214M845	List: ML20214M842 ML20214M861
References
TAC-R00126, TAC-R00127, TAC-R126, TAC-R127, NUDOCS 8706010452
Download: ML20214M861 (8)

Text

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ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-87-11)

PROPOSED AMENDMENT TO SECTION 3/4 11.2 CASEOUS EFFLUENTS, DOSE RATE 4

LIST OF AFFECTED PACES Unit 1 3/4 11-13 Unit 2 3/4 11-11

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- i TABLE 4.11-2 (Continued)

,y TABLE NOTATION '

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b. Sampling and analysis shall also be perf reed following shutdown, startup, or a thermal power change exc ding 15% of rated thermal power within I hour unless (1) analys shows that the dose equiva- R46 lent I-131 concentration in the pri ry coolant has not increased more than a factor of 3 and (2) the noble gas activity monito shows that the Offh=t =tivity has not increased by more than a f ctor of 3.

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c. Tritium grab samples shall be taken at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when the refueling canal is flooded.

d. Samples shall be changed at least once per 7 days and analyses shall '

be completed within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after changing (or after removal from sampler). Sampling shall also be performed at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for at least 2 days following each shutdown from 215% RATED THERMAL * .

POWER, startup of 215% RATED THERMAL POWER or THERMAL POWER change exceeding 15% of RATED THERMAL POWER in one hour and analyses shall be completed within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of changing. .When samples collected for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> are analyzed, the corresponding LLD's may be increased

, by a factor of 10.

. e. Tritium grab samples shall be taken at least once per 7 days from B

' the ventilation exhaust from the' spent fuel pool area, whenever spent fuel is in the spent fuel pool,

f. The ratio of the sample flow rate to the sampled stream flow rate shall be known for the time period covered by each dose or dose rate calculation made in accordance with Specifications 3.11.2.1, 3.11.2.2 and 3.11.2.3.

g. The principal gamma emitters for which the LLD specification applies exclusively are the following radionuclides: Kr-87, Kr-88, Xe-133, Xe-133m, Xe-135, and Xe-138 for noble gases and Mn-54, Fe-59, I-131, Co-58, Co-60, 2n-65, Mo-99, Cs-134 Cs-137, Ce-141 and Ce-144 for particulate principal gamma emitters. This list does not mean that R46 only these nuclides are to be detected and reported. Other gamma peaks which are measureable and identifiable, together with the above nuclides, shall also be analyzed and reported in the Semi-annual Radioactive Effluent Release Report pursuant to Specification 6.9.1.12.

h. During releases via this exhaust system.

i. Purging - Apolicable in MODES 1, 2, 3 and 4, the upper and lower com-partments of the containment shall be sampled prior to PURGING. Prior to breaking containment integrity in MODE 5 or 6, the upper and lower compartments of the containment shall be sampled. The incore instru. R46 ment room purge sample shall be obtained at the shield building exhaust

. between 20 and 25 minutes following initiation of the incore instrument room purge.

January 14, 1986 SEQUOYAH - UNIT 1 3/4 11-13 Amendment No. 42 R46 A

TABLE 4.11-2 (Continued)

TABLE NOTATION a.

The LLD is defined, for the purposes of these specifications, as the smallest concentration of radioactive material in a sample that will yield a net count above system background that will be detected with 95% probability a34 with only a 5% probability of falsely concluding that a blank observation represents a "real" signal.

For a particular measurement system (which may include radiochemical separation):

4.66 s O* E V 2.22x10' Y exp (-A at) R34 Where:

LLD is the "a priori" lower limit of detection as defined above in microcurie per unit mass or volume, 83' s d u is the standard 'eviation of the background counting rate or of tile counting rate of a blank sample as appropriate (as counts per minute),

E is the counting efficiency as counts per disintegrat.fon, g3c V is the sample size in units of mass or volume, 2.22 x 10s is the number of disintegrations per minute per microcurie, Y is the fractional radiochemical yield (when applicable),

A is the radioactive. decay constant for the particular radionuclide, and At for plant effluents is the elapsed time between midpoint of sample p34 collection and time of counting (midpoint).

It should be noted that the LLD is defined as an a priori (before the fact) limit representing the capability of a measurement system and g34 not as an a posteriori (after the fact) Ifmit for a particular measurement.

f b.

Sampling and analysis shall also be per,bormed following shutdown, startup, or a thermal power change excdeding 15% of rated thermal powerwithin1hourunless(1)analys/sshowsthatthedoseequiva-lentI-131concentrationinthepriprycoolanthasnotincreased more than a factor of 3 and (2) the noble gas activity monitor 5 shows that the effhent-eetMty has not increased by more than factor of 3. s2' &bse M dy (ff-@-/86 x ff-fD-//2)

January 14, I '

SEQU0YAH - UNIT 2 3/4 11-11 AmendmentNo.g6 R34

ENCLOSURE 2 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2

DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-87-11)

DESCRIPTION AND JUSTIFICATION FOR THE PROPOSED AMENDMENT TO SECTION 3/4 11.2 GASEOUS EFFLUENTS, DOSE RATE t

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l ENCLOSURE 2 Description of channe I The proposed amendment would affect the following modification to Section 3/4 11.2, " Gaseous Effluents, Dose Rate," for both the unit 1 -

and unit 2 technical specifications:

- Footnote b of table 4.11-2 of surveillance requirement (SR) 4.11.2.1.2 to limiting condition for operation (LCO) 3.11.2.1 would be modified to require sampling to be performed using upper and lower containment noble gas activity monitors rather than the Shield Building stack monitor as is currently called for in the subject footnote.

Reason for Chante The proposed amendment will provide for both a more accurate radiological evaldation of activity levels in containment atmosphere and a'more timely notification to the plant operators of an increase in activity level in containment atmosphere following the events for which SR 4.11.2.1.2 is applicable.

Justification for Change The justification for the change that would be affected by the proposed amendment is as follows:

- The purpose of footnote b of table 4.11-2 is to initiate sampling of specified effluent pathways when increases in reactor coolant and containment atmosphere activity are r

noted. Footnote b of table 4.11-2 currently identifies

" effluent activity" as being representative of containment atmosphere activity. The " effluent activity" is monitored at the Shield Building stack. During normal operations, flow rate through the Shield Building stack is low; activity i

measurements made at this location will not necessarily be an accurate or timely indication of containment atmosphere activity.

- The use of radiation monitors sampling from inside containment would provide for prompt detection and operator alert of high levels of activity in the containment atmosphere. Two such monitors are available for this purpose; one sampling from in the containment lower i compartment, designated RE-90-106, and one sampling from in i the containment upper compartment, designated RE-90-112.

l Both instruments continuously sample the upper and lower compartments and are interconnected by stainless I

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s; .a steeltubingtoensurecbntinuouscontainrrentmonitoring, should one of the monitor assemblies malfunction.

Thus, the use of containment radiation monitors will provide for both the accurate evaluation of activity in the containment atmosphere and -

N 'a timely notification to the operators of any increase in the level

'of containment atmosphere activity.

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ENCLOSURE 3 PROPOSED TECHNICAL SPECIFICATION CHANCE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-87-11)

DETERMINATION OF NO SIGNIFICANT HAZARD CONSIDERATIONS FOR THE PROPOSED AMENDMENT TO SECTION 3/4 11.2 GASEOUS EFFLUENTS, DOSE RATE w

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I ENCLOSURE 3 SIGNIFICANT HAZARDS CONSIDERATION j 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

No. The proposed amendment would provide for a more accurate and timely evaluation of the need to perform a sampling and analysis of the containment atmosphere following shutdown, startup, or a thermal power change exceeding 15 percent of rated thermal power. The basis for the evaluation would be obtained using existing radiation monitoring instrumentation. The proposed amendment does not change plant hardware, plant operating setpoints or limits, or plant operating procedures. Thus, the proposed amendment involves no i.; increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed amendment create the possibility of a new or different kind of" accident from any accident previously evaluated?

No. As previously stated, the proposed amendment does not change plant hardware, plant operating setpoints or limits, or plant operating procedures. The proposed amendment would only utilize i existing instrumentation that will provide both a representative and timely evaluation of containment atmosphere activity. Thus, the proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

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3. Does the proposed amendment involve a significant reduction in the margin of safety?

No. Again, as previously stated, the proposed amendment does not change plant hardware, plant operating setpoints or limits, or plant operating procedures. The proposed amendment would, however, result in the utilization of existing instrumentation that will provide both

, a representative and timely evaluation of containment atmosphere I activity.' Thus, the proposed amendment would involve no reduction in the margin of safety, but rather increases the margin of safety.

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