ML18031B207
| ML18031B207 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 02/11/1987 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML18031B206 | List: |
| References | |
| TAC-64709, TAC-64710, TAC-64711, NUDOCS 8702240401 | |
| Download: ML18031B207 (23) | |
Text
3.7/4.7 CONTAINMENT SYSTEMS LIMITING CONDITIONS FOR OPERATION 3.7.B.
Standb Gas Treatment S stem SURVEILLANCE REQUIREMENTS 4.7.B.
Standb Gas Treatment
~Ss tern 2.
a.
The results of the in-place cold DOP and halogenated hydrocarbon tests at > 10%
design flow on HEPA filters and charcoal adsorber banks shall show >99%
DOP removal and >997. halogenated hydrocarbon removal when tested in accordance with ANSI N510-1975.
2e ae The tests and sample analysis of Specification 3.7.B.2 shall be performed at least once per operating cycle or once every 18 months whichever occurs first for standby service or after every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of system operation and following significant painting, fire or chemical release in any ventilation zone communicating with the system.
b.
The results of laboratory carbon sample analysis shall show >907 radioactive methyl iodide removal when tested in accordance with ASTM D3803 (130'C, 95'L R,H.).
- b. Cold DOP testing shall be performed after each complete or partial replacement of the HEPA filter bank or after any structural maintenance on the system housing.
c.
System shall be shown to operate within +10'L design flow.
Cs Halogenated hydrocarbon testing shall be performed after each complete or partial replacement of the charcoal adsorber bank or after any structural maintenance on the system housing.
BFN Unit 1, 2, 3
PDR ADOCK 05000259 P
3,7/4.7-14
I ~
3.7/4.7 CONTAINMENT SYSTEMS LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.7.E, Control Room Emer enc Ventilation 4.7.E Control Room Emer enc Ventilation
- 1. Except as specified in Specification 3.7.E.3 below, both control room emergency pressurization systems shall be OPERABLE at all times when any reactor vessel contains irradiated fuel.
- 1. At least once per operating cycle, not to exceed 18 months, the pressure drop across the combined HEPA filters and charcoal adsorber banks shall be demonstrated to to be less than 6 inches of water at system design flow rate
(+ 10%).
- 2. a.
The results of the in-place cold DOP and halogenated hydrocarbon tests at design flows on HEPA filters and charcoal adsorber banks shall show >99'L DOP removal and
>99% halogenated hydrocarbon removal when tested in accordance with ANSI N510-1975.
2e ai The tests and sample analysis of Specification 3.7.E.2 shall be performed at least once per operating cycle or once every 18 months, whichever occurs first for standby service or after every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of system operation and following significant painting, fire, or chemical release in any ventilation zone communicating with the system.
b.
The results of laboratory carbon sample analysis shall show >907 radioactive methyl iodide removal at a velocity when tested in accordance with ASTM D3803 (130 C, 95% R.H,).
- b. Cold DOP testing shall be performed after each complete or partial replacement of the HEPA filter bank or after any structural maintenance on the system housing.
- c. System flow rate shall be shown to be within +10'L design flow when tested in accordance with ANSI N510-1975.
co Halogenated hydrocarbon testing shall be performed after each complete or partial replacement of the charcoal adsorber bank or after any structural maintenance on the system housing.
d.
Each circuit shall be operated at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> every month.
BFN Unit 1, 2, 3
3,7/4.7-19
3.7/4.7 CONTAINMENT SYSTEMS LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.7,F.
Primar Containment Pur e
~Ss tern 4.7.F.
Primar Containment Pur e
~Set em 1.
The primaxy containment shall be normally vented and purged through the primary containment purge system.
The standby gas treatment system may be used when primary containment purge system is INOPERABLE,
- 1. At least once per operating cycle, not to exceed 18 months, the pressure drop across the combined HEPA filters and charcoal adsorber banks shall be demonstrated to be less than 8.5 inches of water at system design flow rate
(+ 10'L).
2.
a.
The results of the in-place cold DOP and halogenated hydrocarbon tests at design flows on HEPA filters and charcoal adsorber banks shall show >99%
DOP removal and
>99'L halogenated hydrocarbon removal when tested in accordance with ANSI N510-1975, 2.
a.
The tests and sample analysis of Specification 3.7.F,2 shall be performed at least once per operating cycle or once every 18 months, whichever occurs first or after 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of system operation and following significant painting, fire, or chemical release in any ventilation zone communicating with the system.
b.
The results of laboratory carbon sample analysis shall show >85% radioactive methyl iodide removal when tested in accordance with ASTM D3803 (130'C 95% R.H.).
c.
System flow rate shall be shown to be within +10% of design flow when tested in accordance with ANSI NS10-1975.
- b. Cold DOP testing shall be performed after each complete or partial replacement of the HEPA filter bank or after any structural maintenance on the system housing.
- c. Halogenated hydrocarbon testing shall be performed after each complete or partial replacement of the charcoal adsorber bank or after any structural maintenance on the system
- housing, BFN Unit 1, 2, 3
=3.7/4.7-21
4 l
3.7/4.7 BASES (Cont'd)
The primary containment leak rate test frequency is based on maintaining adequate assurance that the leak rate remains within the specification.
The leak rate test frequency is based on'he NRC guide for developing leak rate testing and surveillance of reactor containment vessels.
Allowing the test intervals to be extended up to 10 months permits some flexibilityneeded to have the tests coincide with scheduled or unscheduled shutdown periods, The penetration and air purge piping leakage test frequency, along with the containment leak rate tests, is adequate to allow detection of leakage trends.
Whenever a bolted double-gasketed penetration is broken and remade, the space between the gaskets is pressurized to determine that the seals are performing properly. It is expected that the majority of the leakage from valves, penetrations and seals would be into the reactor building.
- However, it is possible that leakage into other parts of the facility could occur.
Such leakage paths that may affect significantly the consequences of accidents are to be minimized, The primary containment is normally slightly pressurized during period of reactor operation.
Nitrogen used for inerting could leak out of the containment but air could not leak in to increase oxygen concentration.
Once the containment is filled with nitrogen to the required concentration, determining the oxygen concentration twice a week serves as an added assurance that the oxygen concentration will not exceed 4 percent.
3.7.B/3.7.C Standb Gas Treatment S stem and Secondar Containment The secondary containment is designed to minimize any ground level release of radioactive materials which might result from a serious accident.
The reactor building provides secondary containment during reactor operation, when the drywell is sealed and in service; the reactor building provides primary containment when the reactor is shutdown and the drywell is open, as during refueling.
Because the secondary containment is an integral part of the complete containment
- system, secondary containment is required at all times that primary containment is required as well as during refueling.
The standby gas treatment system is designed to filter and exhaust the reactor building atmosphere to the stack during secondary containment isolation conditions.
All three standby gas treatment system fans are designed to automatically start upon containment isolation and to maintain the reactor building pressure to the design negative pressure so that all leakage should be in-leakage.
High efficiency particulate air (HEPA) filters are installed before and after the charcoal absorbers to minimize potential release of particulates to the environment and to prevent clogging of the iodine absorbers.
The charcoal absorbers are installed to reduce the potential release of radioiodine to the environment.
The in-place test results should indicate a system leak tightness of less than 1 percent bypass leakage for the charcoal absorbers and a
HEPA efficiency of at least 99 percent removal of DOP particulates.
The laboratory carbon sample test results should indicate a radioactive methyl iodide removal efficiency of at least 90 percent for expected accident conditions. If the efficiencies of the HEPA filters and charcoal absorbers are as specified, the resulting doses will be less than the 10 CFR 100 guidelines for the accidents analyzed.
Operation of the fans significantly different from the design flow will change the removal efficiency of the HEPA filters and charcoal absorbers.
BFN Unit 1, 2
3.7/4,7-47
nt I ~
, ~
3.7/4.7 BASES (Cont'd)
The primary containment leak rate test frequency is based on maintaining adequate assurance that the leak rate remains within the specification.
The leak rate test frequency is based on'he NRC guide for developing leak rate testing and surveillance of reactor containment vessels.
Allowing the test intervals to be extended up to 10 months permits some flexibilityneeded to have the tests coincide with scheduled or unscheduled shutdown periods, The penetration and air purge piping leakage test frequency, along with the containment leak rate tests, is adequate to allow detection of leakage trends.
Whenever a bolted double-gasketed penetration is broken and remade, the space between the gaskets is pressurized to determine that the seals are performing properly. It is expected that the majority of the leakage from valves, penetrations and seals would be into the reactor building.
- However, it is possible that leakage into other parts of the facility could occur.
Such leakage paths that may affect significantly the consequences of accidents are to be minimized.
The primary containment is normally slightly pressurized during period of reactor operation.
Nitrogen used for inerting could leak out of the containment but air could not leak in to increase oxygen concentration, Once the containment is filled with nitrogen to the required concentration, determining the oxygen concentration twice a week serves as an added assurance that the oxygen concentration will not exceed 4 percent.
3.7.B/3.7.C Standb Gas Treatment S stem and Secondar Containment The secondary containment is designed to minimize any ground level release of radioactive materials which might result from a serious accident.
The reactor building provides secondary containment during reactor operation, when the drywell is sealed and in service; the reactor building provides primary containment when the reactor is shutdown and the drywell is open, as during refueling.
Because the secondary containment is an integral part of the complete containment
- system, secondary containment is required at all times that primary containment is required as well as during refueling.
The standby gas treatment system is designed to filter and exhaust the reactor building atmosphere to the stack during secondary containment isolation conditions.
All three standby gas treatment system fans are designed to automatically start upon containment isolation and to'maintain the reactor building pressure to the design negative pressure so that all leakage should be in-leakage.
High efficiency particulate air (HEPA) filters are installed before and after the charcoal absorbers to minimize potential release of particulates to the environment and to prevent clogging of the iodine absorbers, The charcoal absorbers are installed to reduce the potential release of radioiodine to the environment.
The in-place test results should indicate a system leak tightness of less than 1 percent bypass leakage for the charcoal absorbers and a HEPA efficiency of at least 99 percent removal of DOP particulates.
The laboratory carbon sample test results should indicate a radioactive methyl iodide removal efficiency of at least 90 percent for expected accident conditions. If the efficiencies of the HEPA filters and charcoal absorbers are as specified, the resulting doses will be less than the 10 CPR 100 guidelines for the accidents analyzed.
Operation of the fans significantly different from the design flow will change the removal efficiency of the HEPA filters and charcoal absorbers, BFN 3.7/4.7-4S Unit 3
l
3.7/4.7 BASES (Cont'd)
Only two of the three standby gas treatment systems are needed to clean up the reactor building atmosphere upon containment isolation, If one system is found to be inoperable, there is no immedi'ate threat to the containment system performance and reactor operation or refueling operation may continue while repairs are being made.
If more than one train is inoperable, the plant is brought to a condition where the standby gas treatment system is not required.
4.7.B/4,7.C Standb Gas Treatment S stem and Secondar Containment Initiating reactor building isolation and operation of the standby gas treatment system to maintain at least a 1/4 inch of water vacuum within the secondary containment provides an adequate test of the operation of the reactor building isolation valves, leak tightness of the reactor building and performance of the standby gas treatment system.
Functionally testing the initiating sensors and associated trip logic demonstrates the capability for automatic actuation.
Performing these tests prior to refueling will demonstrate secondary containment capability prior to the time the primary containment is opened for refueling.
Periodic testing gives sufficient confidence of reactor building integrity and standby gas treatment system performance capability, The test frequencies are adequate to detect equipment deterioration prior to significant defects, but the tests are not frequent enough to load the filters, thus reducing their reserve capacity too quickly.
That the testing frequency is adequate to detect deterioration was demonstrated by the tests which showed no loss of filter efficiency after two years of operation in
~the ru ed shipboard environment on the US Savannah (ORNL 3726).
Pressure drop across the combined HEPA filters and charcoal adsorbers of less than six inches of water at the system design flow rate will indicate that the filters and adsorbers are not clogged by excessive amounts of foreign matter.
Heater capability, pressure dxop and air distribution should be determined at least once per operating cycle to show system performance capability.
The frequency of tests and sample analysis are necessary to show that the HEPA filters and charcoal adsorbers can perform as evaluated.
Tests of the charcoal adsorbers with halogenated hydrocarbon refrigerant shall be performed in accordance with VSAEC Report DP-1082, Iodine removal efficiency tests shall follow ASTM D3803.
The charcoal adsorber efficiency test procedures should allow for the removal of one adsorber tra, emptying of one bed from the tray, mixing the adsorbent thoroughly and obtaining at least two samples.
Each sample should be at least two inches in diameter and a length equal to the thickness of the bed. If test results are unacceptable, all adsorbent in the system shall be replaced with an adsorbent qualified according to Table 1
The replacement tray for the adsorber tray removed for the test should meet the same adsorbent quality, Tests of the HEPA filters with DOP aerosol shall be performed in accordance to ANSI N510-1975.
Any HEPA filters found defective shall be replaced with filters qualified pursuant to Regulatory Position C,3,d of Regulatory Guide 1.52.
All elements of the heater should be demonstrated to be functional and operable during the test of heater capacity.
Operation of each filter train for a minimum of 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> each month will prevent moisture buildup in the filters and adsorber
- system, BFN Unit 1, 2
3.7/4.7-48
l
3.7/4.7 BASES (Cont'd)
Only two of the three standby gas treatment systems are needed to clean up the reactor building atmosphere upon containment isolation. If one system is found to be inoperable, there is no immediate threat to the containment system performance and reactor operation or refueling operation may continue while repairs are being made. If more than one train is inoperable, the plant is brought to a condition where the standby gas treatment system is not required.
4.7.B/4.7.C Standb
. Gas Treatment S stem and Secondar Containment Initiating reactor building isolation and operation of the standby gas treatment system to maintain at least a 1/4 inch of water vacuum within the secondary containment provides an adequate test of the operation of the reactor building isolation valves, leak tightness of the reactor building and performance of the standby gas treatment system.
Functionally testing the initiating sensors and associated trip logic demonstrates the capability for automatic actuation.
Performing these tests prior to refueling will demonstrate secondary containment capability prior to the time the primary containment is opened for refueling.
Periodic testing gives sufficient confidence of reactor building integrity and standby gas treatment system performance capability.
The test frequencies are adequate to detect equipment deterioration prior to significant defects, but the tests are not frequent enough to load the filters, thus reducing their reserve capacity too quickly.
That the testing frequency is adequate to detect deterioration was demonstrated by the tests which showed no loss of filter efficiency after two years of operation in
~the ru ed shipboard environment on the US Savannah (OidlL 3726).
Pressure drop across the combined HEPA filters and charcoal adsorbers of less than six inches of water at the system design flow rate will indicate that the filters and adsorbers are not clogged by excessive amounts of foreign matter, Heater capability, pressure drop and air distribution should be determined at least once per operating cycle to show system performance capability.
The frequency of tests and sample analysis are necessary to show that the HEPA filters and charcoal adsorbers can perform as evaluated.
Tests of the charcoal,adsorbers with halogenated hydrocarbon refrigerant shall be performed in accordance with USAEC Report DP-1082.
Iodine removal efficiency tests shall follow ASTM D3803.
The charcoal adsorber efficiency test procedures should allow for the removal of one adsorber tra, emptying of one bed from the tray, mixing the adsorbent thoroughly and obtaining at least two samples.
Each sample should be at least two inches in diameter and a length equal to the thickness of the bed. If test results are unacceptable, all adsorbent in the system shall be replaced with an adsorbent qualified according to Table 1
The replacement tray for the adsorber tray removed for the test should meet the same adsorbent quality.
Tests of the HEPA filters with DOP aerosol shall be performed in accordance to ANSI N510-1975.
Any HEPA filters found defective shall be replaced with filters qualified pursuant to Regulatory Position C.3,d of Regulatory Guide 1.52.
All elements of the heater should be demonstrated to be functional and operable during the test of heater capacity.
Operation of each filter train for a minimum of 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> each month will prevent moisture buildup in the filters and adsorber system.
BFN Unit 3 3.7/4.7-46
3.7/4.7 BASES (Cont'd) 3.7.E/4.7.E Control Room Emer enc Ventilation The control room emergency ventilati'on system is designed to filter the control room atmosphere for intake air and/or for recirculation during control room isolation conditions.
The control room emergency ventilation system is designed to automatically start upon control room isolation and to maintain the control room pressure to the design positive pressure so that all leakage should be out leakage, High efficiency particulate absolute (HEPA) filters are installed before the charcoal adsorbers to prevent clogging of the iodine adsorbers.
The charcoal adsorbers are installed to reduce the potential intake of radioiodine to the control room.
The in-place test results should indicate a system leak tightness of less than 1 percent bypass leakage for the charcoal adsorbers and a
HEPA efficiency of at least 99 percent removal of DOP particulates.
The laboratory carbon sample test results should indicate a radioactive methyl iodide removal efficiency of at least 90 percent for expected accident conditions. If the efficiencies of the HEPA filters and charcoal adsorbers are as specified, the resulting doses will be less than the allowable levels stated in Criterion 19 of the General Design Criteria for Nuclear Power
- Plants, Appendix A to 10 CFR Part 50.
Operation of the fans significantly different from the design flow will change the removal efficiency of the HEPA filters and charcoal adsorbers.
If the system is found to be inoperable, there is no immediate threat to the control room and reactor operation or refueling operation may continue for a limited period of time while repairs are being made.
If the system cannot be repaired within seven
- days, the reactor is shutdown and brought to Cold Shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or refueling operations are terminated.
'Pressure drop across the combined HEPA filters and charcoal adsorbers of less than six inches of water at the system design flow rate will indicate that the filters and adsorbers are not clogged by excessive amounts of foreign matter.
Pressure drop should be determined at least once per operating cycle to show system performance capability.
The frequency of tests and sample analysis are necessary to show that the HEPA filters and charcoal adsorbers can perform as evaluated.
Tests of the charcoal adsorbers with halogenated hydrocarbon shall be performed in accordance with USAEC Report-1082.
Iodine removal efficiency tests shall follow ASTM D3803, The charcoal adsorber efficiency test procedures should allow for the removal of one adsorber tray, emptying of one bed from the tray, mixing the adsorbent 'thoroughly and obtaining at least two samples.
Each sample should be at least two inches in diameter and a length equal to the thickness of the bed. If test results are unacceptable, all adsorbent in the system shall be replaced with an adsorbent qualified according to Table 1 of Regulatory Guide 1.52.
The replacement tray for the adsorber tray removed for the test should meet the same adsorbent quality.
Tests of the HEPA filters with DOP aerosol shall be performed in accordance to ANSI N510-1975.
Any HEPA filters found defective shall be replaced with filters qualified pursuant to Regulatory Position C.3.d of Regulatory Guide 1.52.
BFN Unit 1,2 3.7/4.7-51
- 3. 7/4. 7 BASES (Con t')
3.7.E/4.7.E Control Room Emer enc Ventilation The control room emergency ventilati'on system is designed to filter the control room atmosphere for intake air and/or for recirculation during control room isolation conditions.
The control room emergency ventilation system is designed to automatically start upon control room isolation and to maintain the control room pressure to the design positive pressure so that all leakage should be out leakage.
High efficiency particulate absolute
<HEPA) filters are installed before the charcoal adsorbers to prevent clogging of the iodine adsorbers, The charcoal adsorbers are installed to reduce the potential intake of radioiodine to the control room.
The in-place test results should indicate a system leak tightness of less than 1 percent bypass leakage for the charcoal adsorbers and a
HEPA efficiency of at least 99 percent removal of DOP particulates.
The laboratory carbon sample test results should indicate a radioactive methyl iodide removal efficiency of at least 90 percent for expected accident conditions. If the efficiencies of the HEPA filters and charcoal adsorbers are as specified, the resulting doses will be less than the allowable levels stated in Criterion 19 of the General Design Criteria for Nuclear Power
- Plants, Appendix A to 10 CFR Part 50.
Operation of the fans significantly different from the design flow will change the removal efficiency of the HEPA filters and charcoal adsorbers, If the system is found to be inoperable, there is no immediate threat to the control room and reactor operation or refueling operation may continue for a limited period of time while repairs are being made. If the system cannot be
-repaired within seven
- days, the reactor is shutdown and brought to Cold Shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or refueling operations are terminated.
Pressure drop across the combined HEPA filters and charcoal adsorbers of less than six inches of water at the system design flow rate will indicate that the filters and adsorbers are not clogged by excessive amounts of foreign matter.
Pressure drop should be determined at least once per operating cycle to show system performance capability.
The frequency of tests and sample analysis are necessary to show that the HEPA filters and charcoal adsorbers can perform as evaluated.
Tests of the charcoal adsorbers with halogenated hydrocarbon shall be performed in accordance with USAEC Report-1082.
Iodine removal efficiency tests shall follow ASTM D3803, The charcoal adsorber efficiency test procedures should allow for the removal of one adsorber tray, emptying of one bed from the tray, mixing the adsorbent thoroughly and obtaining at least two samples.
Each sample should be at least two inches in diameter and a length equal to the thickness of the bed. If test results are unacceptable, all adsorbent in the system shall be replaced with an adsorbent qualified according to Table 1 of Regulatory Guide 1.52.
The replacement tray for the adsorber tray removed for the test should meet the same adsorbent quality.
Tests of the HEPA filters with DOP aerosol shall be performed in accordance to ANSI N510-1975.
Any HEPA filters found defective shall be replaced with filters qualified pursuant to Regulatory Position C.3.d of Regulatory Guide 1.52, M"t 3 3.7/4.7-49
3.7/4.7 BASES (Cont'd)
Operation of the system for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> every month will demonstrate operability of the filters and adsorber system and remove excessive moisture built up on the adsorber.
If significant painting, fire or chemical release occurs such that the HEPA filter or charcoal adsorber could become contaminated from the fumes, chemicals or foreign materials, the same tests and sample analysis shall be performed as required for operational use.
The determination of significance shall be made by the operator on duty at the time of the incident.
Knowledgeable staff members should be consulted prior to making this determination.
Demonstration of the automatic initiation capability is necessary to assure system performance capability.
3.7.F/4.7.F Primar Containment Pur e
S stem The primary containment purge system is designed to provide air to purge and ventilate the primary containment system.
The exhaust from the primary containment is first processed by a filter train assembly and then channeled through the reactor building roof exhaust system.
During power operation, the primary containment purge and ventilation system is isolated from the primary containment by two isolation valves in series.
HEPA (high efficiency particulate air) filters are installed before the charcoal adsorbers followed by a centrifugal fan.
The in-place test results should indicate a leak tightness of the system housing of not less than 99-percent and a HEPA efficiency of at least 99-percent removal of DOP particulates.
The laboratory carbon sample test results should indicate a
radioactive methyl iodide removal efficiency of at least 85-percent.
Operation of the fans significantly different from the design flow will change the removal efficiency of the HEPA filters and charcoal adsorbers.
If the system is found to be inoperable, the Standby Gas Treatment System may be used to purge the containment.
Pressure drop across the combined HEPA filters and charcoal adsorbers of less than 8.5 inches of water at the system design flow rate will indicate that the filters and adsorbers are not clogged by excessive amounts of foreign matter.
Pressure drop should be determined at least once per operating cycle to show system performance capability.
The frequency of tests and sample analysis are necessary to show that the HEPA filters and charcoal adsorbers can perform as evaluated.
Tests of the charcoal adsorbers with halogenated hydrocarbon shall be performed in accordance with USAEC Report-1082.
Iodine removal efficiency tests shall follow ASTM D3803, The charcoal adsorber efficiency test procedures should allow for the removal of one adsorber tray, emptying of one bed from the tray, mixing the adsorbent thoroughly and obtaining at least two samples.
Each sample should be at least two inches in diameter and a length equal to the thickness of the bed, If test results are unacceptable, all adsorbent in the system shall be replaced with an adsorbent qualified according to Table 1 of Regulatory Guide 1.52.
The replacement tray for the adsorber tray removed BF5 unct 1, 2
3.7/4.7-52
3.7/4.7 BASES (Cont'd)
Operation of the system for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> every month will demonstrate operability of the filters and adsorber system and remove excessive moisture built up on the adsorber, If significant painting, fire or chemical release occurs such that the HEPA filter or charcoal adsorber could become contaminated from the fumes, chemicals or foreign materials, the same tests and sample analysis shall be performed as required for operational use.
The determination of significance shall be made by the operator on duty at the time of the incident.
Knowledgeable staff members should be consulted prior to making this determination.
Demonstration of the automatic initiation capability is necessary to assure system performance capability.
3.7.F/4.7.F Primar Containment Pur e
S stem The primary containment purge system is designed to provide air to purge and ventilate the primary containment system.
The exhaust from the primary containment is first processed by a filter train assembly and then channeled through the reactor building roof exhaust
- system, During power operation, the primary containment purge and ventilation system is isolated from the primary containment by two isolation valves in series.
HEPA (high efficiency particulate air) filters are installed before the charcoal adsorbers followed by a centrifugal fan.
The in-place test results should indicate a leak tightness of the system housing of not less than 99-percent and a
HEPA efficiency of at least 99-percent removal of DOP particulates.
The laboratory carbon sample test results should indicate a
radioactive methyl iodide removal efficiency of at least 85-percent.
Operation of the fans significantly different from the design flow will change the removal efficiency of the HEPA filters and charcoal adsorbers.
If the system is found to be inoperable, the Standby Gas Treatment System may be used to purge the containment.
Pressure drop across the combined HEPA filters and charcoal adsorbers of less than 8.5 inches of water at the system design flow rate will indicate that the filters and adsorbers are not clogged by excessive amounts of foreign matter.
Pressure drop should be determined at least once per operating cycle to show system performance capability, The frequency of tests and sample analysis are necessary to show that the HEPA filters and charcoal adsorbers can perform as evaluated.
Tests of the charcoal adsorbers with halogenated hydrocarbon shall be performed in accordance with USAEC Report-1082.
Iodine removal efficiency, tests shall follow ASTM D3803.
The charcoal adsorber efficiency test procedures should allow for the removal of one adsorber tray, emptying of one bed from the tray, mixing the adsorbent thoroughly and obtaining at least two samples.
Each sample should be at least two inches in diameter and a length equal to the thickness of the bed. If test results are unacceptable, all adsorbent in the system shall be replaced with an adsorbent qualified according to Table 1 of Regulatory Guide 1.52.
The replacement tray for the adsorber tray removed BFN Unit 3 3.7/4.7-50
ENCLOSURE 2
DESCRIPTION AND JUSTIFICATION BROWNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 Descri tion of Chan e
Technical specifications 3.7.B.2.b, 3.7.E.2.b, and 3.7.F.2.b are changed to reference the test method in ASTM D3803 vice ANSI N510-1975 for laboratory tests to demonstrate radioactive methyl iodide removal by carbon filter samples.
The Bases pages are also updated for section 3.7 to reflect these changes.
Reason for Chan e
The change is needed to xeflect the proper test method since ANSI N510-1975 is specifically for new charcoal whereas Regulatory Guide 1.52 refers to ASTM D3803 procedure for laboratory testing of samples of both new and used chaxcoal.
This amendment is required to resolve Inspection and Enforcement Repoxt 85-57.
Justification for Chan e
The proposed amendment to the technical specifications for units 1, 2, and 3
is justified on the basis that it will coxrect a reference to an improper procedure.
By specifying the correct procedure, a more accurate and consexvative determination of the condition of the charcoal filtex's is obtained.
These tests are performed on samples taken from the charcoal filters in the Standby Gas Treatment
- System, Control Room Emergency Ventilation, and Primary Containment Purge System.
The test analyses are used to determine when the charcoal filters in these systems are to be replaced.
Referencing a proper test method will not change any system operations and will clarify and improve the testing requirements.
For these
- reasons, TVA has concluded that this proposed technical specification change will not reduce the margin of nuclear safety.
P
ENCLOSURE 3
DETERMINATXON OF. NO SIGNIFICANT HAZARDS CONSIDERATION BROMNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 Descri tion of Amendment The proposed amendment would modify the technical specifications of BFN units 1, 2, and 3 to reflect the use of a more recent and proper standard, (ASTM 3803 vice ANSX N510-1975) for testing the capability of carbon filters to remove radioactive methyl iodide.
Basis for ro osed No Si nificant Hazards Consideration Determination The Connnission has provided standards for determining whether a significant hazards consider'ation exists as stated in 10 CFR 50.92(c).
A proposed amendment to an operating license involves no significant hazards considerations if operation of the facility in accordance with the proposed amendment would not:
(1) involve a significant increase in the probability or consequences of an accident previously evaluated, or (2) create the possibility of a new or different kind of accident from an accident previously evaluated, or (3) involve a significant reduction in a margin of safety.
This proposed amendment does not efEect the probability or possibility of any accident since it only deals with a test method for laboratory analysis of charcoal filter samples.
No plant equipment or operational procedures will be modified as a result of this amendment.
The proposed amendment will not involve a significant increase in the consequences of an accident since it will only result in more accurate surveillance testing of the iodide removal capabilities oE the charcoal Eilters.
The margin of safety will not be reduced since the technical specifications will only be changed to reference a
proper testing method.which provides more accurate and conservative results.
Since the application Eor amendment involves a proposed change that is encompassed by the criteria Eor which no significant. hazards consideration
- exists, TVA has made a proposed determination that the application involves no significant hazards consideration.