ML20140A847
| ML20140A847 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 05/29/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20140A852 | List: |
| References | |
| NUDOCS 9706050053 | |
| Download: ML20140A847 (1) | |
Text
_ _.. _ _ _ _ _ _ _ _
j !
i These rates are determined by the first-order removal coefficients which, for elemental iodine removal by spray water and deposition on the containment walls, are independent of pH and therefore are not affected by elimination of the pH controlling additive. The same applies to the removal coefficients for particulate iodine, which is controlled by the hydrodynamic characteristics of 3
the spray.
i i
During the recirculation spray phase, coolant from the sump will contain i
dissolved iodine removed from the containment atmosphere during the injection phase.
In a radiation environment this iodine could be desorbed from the l
water and released to the containment atmosphere if the pH of the sump i
solution is too low. Since the long-term pH of the ECCS solution should be no i
less than 7.0, a chemical additive must be utilized to raise the pH of the i
solution in the containment building sump.
The licensee has proposed to control the pH abeve a level of 7.5 by the i
addition of the ECCS recirculation fluid pH controi system. This is a passive j
system that consists of crystalline trisodium phosphate (TSP) stored in three baskets located in the containment sump grea with a total minimum TSP loading of approximately 10,000 pounds (185 feet ).
The TSP baskets are designed to i
Seismic Category 1 standards and would be anchored to the filler slab at an elevation of 105 feet - 6 inches.
In accordance with the proposed ECCS recirculation fluid pH control system TS, the licensee has proposed to verify, during each refueling outage, that the three storage baskets (a) are in place, (b) have maintained their integrity, and (c) are filled with TSP compound such that the level is between the indicated fill marks on the baskets.
l The licensee plans to selectively leave in place or remove the components I
associated with the spray additive system. The blind flanges installed in the eductor lines will meet ASME Code,Section III, Class 2 requirements. The containment spray piping will continue to meet the plant seismic and ASME Code,Section III, Class 2 requirements. The level and flow indicators and hand switches associated with these components will be removed from the main control board and replaced with cover plates.
The sump water must also be maintained in the alkaline condition in order to minimize corrosion of metallic surfaces. Chloride-induced stress corrosion cracking of austenitic stainless steel components is considerably reduced if the pH of the solution is maintained above 7.
During the injection phase, the TSP will begin to dissolve and the pH of the ECCS sump solution will be raised from 4.5 into the range of 7.5 to 10.5. The surfaces sprayed during the injection will be resprayed during the recirculation phase with a high pH solution.
Control of the sump pH is also required to minimize hydrogen generation by corrosion of aluminum and zinc on galvanized surfaces and in the organic coatings on containment surfaces. The proposed change will affect the pH by introducing an initial pH of 4.fg rated water spray) followed by a pH range 9706050053 970529 PDR ADOCK 05000348 P
Itvv' ~
PDR L.
~
7 I
l These rates are determined by the first-order removal coefficients which, for elemental iodine removal by spray water and deposition on the containment walls, are independent of pH and therefore are not affected by elimination of l
the pH controlling additive. The same applies to the removal coefficients for particulate iodine, which is controlled by the hydrodynamic characteristics of the spray.
During the recirculation spray phase, coolant from the sump will contain dissolved iodine removed from the containment atmosphere during the injection phase.
In a radiation environment this iodine could be desorbed from the water and released to the containment atmosphere if the pH of the sump solution is too low. Since the long-term pH of the ECCS solution should be no less than 7.0, a chemical additive must be utilized to raise the pH of the solution in the containment building sump.
Thelicenseehasproposedtocontrd1thepHabovealevelof7.5bythe addition of the ECCS recirculation fluid pH control system. This is a passive system that consists of crystalline trisodium phosphate (TSP) stored in three baskets located in the containment sump grea with a total minimum iSP loading of approximately 10,000 pounds (185 feet ).
The TSP baskets are d w gned to Seismic Category I standards and would be anchored to the filler slab at an i
elevation of 105 feet - 6 inches.
In accordance with the proposed ECM recirculation fluid pH control system TS, the licensee has proposed to verify, during each refueling outage, that the three storage baskets (a) are in pla.ce, (b) have maintained their integrity, and (c) are filled with TSP compound such that the level is between the indicated fill marks on the baskets.
The licensee plans to selectively leave in place or remove the components associated with the spray additive system. The blind flanges installed in the eductor lines will meet ASME Code,Section III, Class 2 requirements. The containment spray piping will continue to meet the plant seismic and ASME Code,Section III, Class 2 requirements. The level and flow indicators and hand switches associated with these components will be removed from the main control board and replaced with cover plates.
l The sump water must also be maintained in the alkaline condition in order to minimize corrosion of metallic surfaces. Chloride-induced stress corrosion
/
cracking of austenitic stainless steel components is considerably reduced if the pH of the solution is maintained above 7.
During the injection phase, the TSP will begin to dissolve and the pH of the ECCS sump solution will be raised from 4.5 into the range of 7.5 to 10.5. The surfaces sprayed during the injection will be resprayed during the recirculation phase with a high pH solution.
J Control of the sump pH is also required to minimize hydrogen generation by corrosion of aluminua and zine on galvanized surfaces and in the organic l
coatings on containment surfaces. The proposed change will affect the pH by introducing an initial pH of 4.5 (borated water spray) followed by a pH range
[hb}
~
~--.
- ....c 4
i i.
These rates are determined by the first-order removal coefficients which, for 3
i elemental iodine removal by spray water and deposition on the containment walls, are independent of pH and therefore are not affected by elimination of the pH controlling additive. The same applies to the removal coefficients for particulate iodine, which is controlled by the hydrodynamic characteristics of the spray.
{
During the recirculation spray phase, coolant from the sump will contain i
dissolved iodine removed from the containment atmosphere during the injection i
phase.
In a radiation environment this iodine could be desorbed from the water and released to the containment atmosphere if the pH of the semp solution is too low. Since the long-tem pH of the ECCS solution should be no less than 7.0, a chemical additive must be utilized to raise the pH of the solution in the containment building sump.
The licensee has proposed to control the pH above a level of 7.5 by the addition of the ECCS recirculation fluid pH control system. This is a passive system that consists of crystalline trisodium phosphate (TSP) stored in three baskets located in the containment sump g)rea with a total minimum TSP loading of approximately 10,000 pounds (185 feet The TSP baskets are designed to Seismic Category I standards and would be anchored to the filler slab at an elevation of 105 feet - 6 inches.
In accordance with the proposed ECCS recirculation fluid pH control system TS, the licensee has proposed to verify, during each refueling outage, that the three storage baskets (a) are in place, (b) have maintained their integrity, and (c are filled with TSP compound such that the level is between the indicated fil marks on the baskets The licensee plans to selectively leave in place or remove the components associated with the spray additive system. The blind flanges installed in the eductor lines will meet ASME Code,Section III, Class 2 requirements. The containment spray piping will continue to meet the plant seismic and ASME Code,Section III, Class 2 requirements. The level and flow indicators and hand switches associated with these components will be removed from the main control board and replaced with cover plates.
The sump water must also be maintained in the alkaline condition in order to minimize corrosion of metallic surfaces. Chloride-induced stress corrosion cracking of austenitic stainless stsel components is considerably reduced if the pH of the solution is maintained dove 7.
During the injection phase, the TSP will begin to dissolve anti the pH of the ECCS sump solution will be raised from 4.5 into the range of 7.5 to 10.5. The surfaces sprayed during the I
injection will be resprayed dt. ring the recirculation phase with a high pH solution.
Control of the sump pH is also required to minimize hydrogen generation by corrosten of aluminum and zine on galvanized surfaces and in the organic coatings on containment surfaces. The proposed change will affect the pH by introducing an initial pH of 4.5 (borated water spray) followed by a pH range N
J
i
{ :
l These rates are determined by tiie first-order removal coefficients which, for elemental iodine removal by spray sater and deposition on the containment f
walls, are independent of pH and therefore are not affected by elimination of the pH controlling additive. The same applies to the removal coefficients for particulate iodine, which is controlled by the hydrodynamic characteristics of the spray.
1 During the recirculation spray phase, coolant from the sump will contain j
dissolved iodine removed from the containment atmosphere during the injection phase.
In a radiation environment this iodine could be desorbed from the i
j water and released to the containment atmosphere if the pH of the sump solution is too low. Since the long-term pH of the ECCS solution should be no i
less than 7.0, a chemical additive must be utilized to raise the pH of the j
solution in the containment building sump.
I l
The licensee has proposed to control the pH above a level of 7.5 by the addition of the ECCS recirculation fluid pH control system. This is a passive system that consists of crystalline trisodium phosphate (TSP) stored in three baskets located in the containment sump g)rea with a total minimum TSP loading i
l of approximately 10,000 pounds (185 feet The TSP baskets are designed to i
Seismic Category I standards and would be anchored to the filler slab at an
{
elevation of 105 feet - 6 inches.
In accordance with the proposed ECCS recirculation fluid pH control system TS, the licensee has proposed to verify, during each refueling outage, that the three storage baskets (a) are in place, (b) have maintained their integrity, and (c) are filled with TSP compound such i
i that the level is between the indicated fill marks on the baskets.
l The licensee plans to selectively leave in place or remove the components associated with the spray additive system. The blind flanges installed in the eductor lines will meet ASME Code,Section III, Class 2 requirements. The i
containment spray piping will continue to meet the plant seismic and ASME j
Code,Section III, Class 2 requirements. The level and flow indicators and i
hand switches associated with these components will be removed from the main control board and replaced with cover plates.
1 The sump water must also be maintained in the alkaline condition in order to minimize corrosion of metallic surfaces. Chloride-induced stress corrosion I
cracking of austenitic stainless steel components is considerably reduced if j
the pH of the solution is maintained above 7.
During the injection phase, the i
TSP will begin to dissolve and the pH of the ECCS sump solution will be raised j
from 4.5 into the range of 7.5 to 10.5. The surfaces sprayed during the i
injection will be resprayed during the recirculation phase with a high pH l
solution.
)
Control of the sump pH is also required to minimize hydrogen generation by corrosion of aluminum and zine on galvanized surfaces and in the organic j
coatings on containment surfaces. The proposed change will affect the pH by introducing an initial pH of 4.5 (borated water spray) followed by a pH range
-