ML20023E257
| ML20023E257 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 06/03/1983 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20023E252 | List: |
| References | |
| NUDOCS 8306150248 | |
| Download: ML20023E257 (10) | |
Text
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ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION REVISIONS BROWNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 TVA BFNP TS 176 SUPPLEMENT 6 M O!kk I
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I UNITS 1 AND 2 e
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LIMITING CONDITIONS FOR OPERATION SURVEII4ANCE REQUIREMENTS 1,'s -
2.
During a complete core removal, the SRM's shall have an initial minimum count rate of 3 cps prior to fuel removal, with all rom
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fully inserted and rendered electrically inoperable. The count rate will diminish during fuel removal. In.fividual control rods outside the periphery of the then existing ibel matrix may be electrically armed and moved for maintenance af ter all fuel in the cell containing (controlled byl that control rod have been removed from the reactor core.
3.10.C Spent Fuel Pool Water 4.10.C Spent Puel Pool Water 1.
Whenever irradiated fuel is 1.
Whenever irradiated fuel is stored in the spent fuel stored in the spent fuel pool, pool, the pool water level the water level and temperature shall be maintained at a shall be recorded daily depth of 8 1/2 feet or greater above the top of the spent fuel. A minimum of 5 -1/2 feet of water shall be maintained over single irradiated fuel l
assemblics during transfer and handling operations.
2.
Whenever irradiate'd fuel is 2.
A sample of fuel pool water in the fuel pool, the pool shall be analyzed in accordance water temperature shall be with the following specifications:
~< 150 F.
a.
At least daily for conductivit 3.
Vuel pool water shall he and chloride ion content.
maintained within the following limits:
b.
At least once por 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for conductivity and chloride conductivity <,10 umhos/cm content when the fuel pool 025'c cleanup system is inoperable.
chlorides < 0.5 ppm i
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UNIT 3 I
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LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 2.
During a complete core removal, the SEM's shall have an initial minimum count rate of 3 con prior to fuel removal. with all rods fully. inserted and rendered electrically inoperable. The
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count rate vill diminish during fuel removal. In.!ividual control rods outr.ide the periphery of the then existang fiu l ina t rix may be electrically anned and moved for maintenance af ter all fuel in the cell containing (controlled byl that control rod have been removed t' rom the reactor core.
3.10.C Spent Fuel Pool Water 4.10.C.Spant Puel Pool Water 1.
Whenever irradiated fuel is 1.
Whenever irradiated fuel is stored in the spent fuel stored in the spent fuel pool, pool, the pool water level the water level and temperature shall be maintained at a shall be recorded daily depth of 8 1/2 feet or greater above the top of the spent fuel. A minimum of 5-1/2 feet of water shall be maintained over singic irradiated fuel assembliss during transfer and handling operations.
2.
Whencver irradiate'd fuel is A sample of fuel pool water 2.
in the fuel pool, the pool shall be analyzed in accordasca vater temperature shall be with the following specificat ions 0
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< 150 7.
a.
At least daily for conductiv!
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3.
Fuel pool water shall be and chlorido ion cor. tent.
maintained within thu following 11cita:
b.
At least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for conductivity and chiarid.
f conductivity ~< 10 u=hos/cm content when the fuel pool I
025'c cleanup system is inoperable l
chlorides < 0.5 ppm l
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ENCLOSURE 2 DESCRIPTION AND JUSTIFICATION OF CHANGES TVA BFNP TS 176 SUPPLEMENT 6 BROWNS FERRY NUCLEAR PLANT The current technical specification 3 10.C.1 requires a minimum of 6-1/2 feet of water be maintained over. single irradiated fuel assemblies during transfer and handling operations. It is proposed to change the limit to 5-1/2 feet of water as a minimum.
Reason for Proposed Change During fuel inspections at Browns Ferry unit 2 for reload 4, the inspectors had to work from the fuel prep machine in a crouching position. By allowing the fuel assembly to be raised higher to maintain 5-1/2 feet of water instead of 6-1/2, feet the inspectors will be able t'o work in a more comfortable position. It is expected that this will reduce the inspection time for a fuel assembly. As discussed in the following Safety Analysis, it is expected that the exposure rate to personnel would not be increased significantly during the Laspection.
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SAFETY ANALYSIS The requirement to maintain 6-1/2 feet of water over single irradiated fuel bundles during transfer and handling operations is overly restrictive in light of the recent unit 2 fuel inspection (ST 8215) and potential future inspections and rod consolidation. The basis for this requirement is not addressed in the FSAR, the basis of the current technical specifications, nor the standardized technical specifications (NUREC-0123, Rev. 3).
- Thus, it cannot be construed to be a safety limit, but rather a health physics requirement to limit exposure of plant personnel.
If it is assumed the exposure due to the bundle can be represented by a point source, the following equation from Reactor Rhieldian for Nuclear Engineers, by N. M. Schaeffer, can be used to estimate the increase in
-ut exposure from the raising of the limit to 5-1/2 feet - W = See 2
4w R
-ut l
-pt, 2
l S*
= Soe 9
9 9 2
2 2
4w R 4w R y
9
[R
,-p G " 1) 2 2
- /6
=
q 2 3 R
C
(
2
)
198.12 cm 6.5 feet =
R
= t
=
g g
i 167.64 cm 5.5 fest l
R
= t
=
=
2 2
p is the linear attenuation coefficient.
From H. Cember's Introduction to Health Physica values of p for water can be found.
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. SAFETY AN ALYSIS (Continued)
For water and x-rays of.1mev, p=
.167 cm-I.
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For water and x-rays of 1mev, p=
.071 cm By raising the limit to 5-1/2 feet the dose rates may be increased by factors of between the following:,
2 Y,.167(30.48) 226.85
=
=
198.12 9 /0 2 1
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(167.64 2
.071(30.48) 12.16
[198.12
=
p #E
=
2 1 I
(167.64 From the previous unit 2 fuel inspection the dose rate experienced was approximately 10 mr/hr which is roughly the dose rate experienced when The portion attributable to the bundle working around the spent fuel pool.
From this the increase in inspection can be estimated at.1 to 1 mr/hr.
exposure due to the higher limit can be estimated between 1 and 226 mr/hr.
The calculation of 226 mr/hr is extremely conservative, Calculations by a different, but equally acceptable, method indicated an expected increase in exposure of.6 to 6 mr/hr.
In either cace, Health Physics l
l requirements will continue to be met by adhering to the requirements of Technical Specification 6.3.D.
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CONCLUSION The overall safety of fuel inspections and rod consolidation can be improved by raising the limit to 5-1/2 feet. This will reduce the possibility of an inspector making an accident and allow the work to proceed more quickly.
The existing inplant Browns Ferry health physics controls and procedures will limit the personnel exposures received by inspection, personnel.
The reduction in fuel inspection time because of the revised assembly level in the pool is expected to result in personnel exposure lower than projected.
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ENCLOSURE 3 SIGNIFICANT HAZARDS CONSIDERATION FOR PROPOSED TECHNICAL SPECIFICATION CHANGE TVA BFNP TS 176 SUPPLEMENT 6 BROWNS FERRY NUCLEAR PLANT 1.
Does the proposed amendment involve a significant increase in s
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the probability or consequences of an accident previously
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' evaluated?
No.
The water level above a single irradiated fuel assembly during transfer and handling will not affect the probability of any accident associated with refueling operations. The basis for this minimum water level is not addressed in the technical specification bases, BWR standard technical specifications, or the FSAR. It is a limit established to limit the exposure to i
personnel during fuel inspections. The safety analysis indicates that the personnel exposure rate may increase slightly from one less foot of water shielding. However, 4
because of a more comfortable working position, it is expected that the inspection will take less time and the resultant total exposure will be reduced.
s 2.
Does the proposed amendment create the probability of a new i
or different -kind of accident from any accident previously evaluated?
No.
The fuel inspection procedure will not change. Only the level of water over the fuel bundle will change. Therefore, the revision will not create the possibility of a new or different kind of accident from any-previously evaluated.
3 Does the proposed amendment involve a significant reduction l
in a margin of. safety?
No.
As stated in (1), the margin of safety will not be reduced
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but may potentially be increased due to the possibility of reducing the time needed to perform the fuel inspection operation.
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