AECM-83-0696, Suppl to Monthly Operating Rept for Sept 1983
| ML20114C513 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 09/30/1983 |
| From: | MISSISSIPPI POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20114C478 | List:
|
| References | |
| FOIA-84-444 AECM-83-0696, AECM-83-696, NUDOCS 8501300331 | |
| Download: ML20114C513 (9) | |
Text
9#3 Atts:rrent tc AECM-83/0696 Page ; cf 9 OPERATING DATA REPORT d
SUPPLEMENTAL INFORMATION
' Major Changes to Radioactive Waste Treatment Systems 1.
Design Change Package (DCP) -82/651, Condensate Phase Separator o
System.
A.
Summ:ry of 10CFR 50.59 Considerations The probability of an occurrence or the consequence of an accident, or malfunction of equipment important to safety as previously evaluated in the Final Safety Analysis Report was not increased because: The design change as described be;ow, did not affect a direct safety function or system important.
to safety, previously evaluated in the FSAR. Therefore, the probability of an occurrence or the consequence of a malfunction of equipment important to safety was not increased.
The postulated worst case failures (radwaste tank rupture and piping leaks) analyzed in FSAR Sections 15.7.2 and 15.7.3 encompass the occurrence and consequence of postulated accidents due to this design change.
Therefore, the
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probability of an occurrence or the consequence of an accident was not increased.
The possibility for an accident or malfunction of a different type ^than those previously evaluated in the Final Safety Analysis Report was not created because: All potentially radioactive portions of the condensate phase separator system are located within the radwaste building and designs were developed in accordance with the'related guidance in Branch Technical Position ETSB 11-1 of NRC Standard Review Plan 11.2.
Theref ore, use of the condensate phase separator system does nct result in releases which differ from those previously predicted in FSAR Section 15.7.2 and 15.7.3 nor is there a change to the maximum exposure to an individual in the unrestricted area.
t The margin of safety, as defined in the basis for the Technical Specification was not reduced because:
The design change did not change the limiting conditions for operation, applicability, actions, or surveillance requirements as defined-in the basis for Technical Specifications 3/4.11.1, 6.12, 6.13, and 6.15.
B.
Reason for Change The Condensate Precoat Filters backwash to the Condensate Clean Waste Tank (CCWT) in the Turbine Building beneath the filters. The CCWT is sized to contain one backwash.
During a plant startup, frequent filter backwashes will be required for short periods of time (about 12 backwashes in a 24-hour s l 9501300331 840709 PDR FOIA SCM.EIFE54-444 PDR
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As originally designed, these backwashed wastes would be pumped from the CCWT to the Waste Surge Tanks and then processed in small batches through the Waste Holding Tanks.
This processing scheme presented two problems.
- First, processing the precoat filter backwashes through the Waste Surge Tanks introduced large quantities of powdered resin filter mas.erial into the Liquid Radwaste Systee.
This r:dicactive filter material would accumulate as a sludge which was difficult to remove from the surge tanks and wtald require additional radwaste filter processing time.
Second, the surge tanks were needed as surge volume for the floor drain system.
C.
Detailed Description of the Change DCP-82/651 provided for the addition of a Condensate Phase Separator subsystem for the Liquid Radwaste System.
The design consisted of two tanks, each sized to contain the solids from five decanted backwashes plus the water and solids from one complete backwash of the Condensate Precoat Filters.
The tanks and associated shield walls were located in the drum storage area adjacent to the shipping bay in the Radwaste Building. The pumps and valves associated with the phase separator tanks were located in shielded compartments in the adjacent area previously occupied by the silica tank and -
concrete hopper of.the now abandoned Radwaste Solidification System.
The tanks will receive slurried wastes from the CCWT.
During stcrtup, wastes will be alternatively directed to one tank, then the other in order to maximize the time available for decanting the excess water.
Decanted liquid will nor= ally be utree:ed to the RW~C Phase Separators, since the liquid may still be turbid.
The liquid may be directed to the Waste Surge Tanks if the RWCU separators are full or if an inadequate decanting period exists.
The sludges in the tanks will be slurriel, recirculated and a representative sample will be pumped to the Waste Holding Tanks for sampling and processing. The remainder of the slurry will then be pumped to the solidification station. The tanks are equipped with an eductor-type sparger for mixing and a spray ring for decontamination.
The tanks are fitted with vent lines to the
-Radwaste Tank Ventilation System, overflow lines with loop seals, and decanting lines at_three levels.
The tanks, piping, and pumps of the system can be flushed with condensate and blown out with service air. Design changes were developed in accordance with applicable ALARA guidelines.
The following design features have been provided by this change:
1.
Two tanks of stainless steel, each with a volume of 15,000 gallons.
2.
Sparger for each tank for fluidizing a settled bed of material prior to discharge.
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_1 AECM-83/0696 Page 3 of 9
't Internal tank spray systems to facilitate tank cleaning or for dilution of the contents.
4.
Sensors to. determine interface level of settled filter precoat material.
5.
High water level sensor and trip signal.
6.
Water _ level sensor with high and low level trip signals.
7.
Tank overflows with loop seals.
8.
Vent with-extern-1 basket strainer for each tank.
9.
Flush. connection. :hich can be canually or automatically sequenced -'with. service air input of air purging as required.
10.
Condensate phase separator pumps each with casing flush capability.
11.
Pump suction and ' discharge. cross - connects provided to enable sharing.of pumps if necessary.
12.
Gravity' decant path from each tank to either the RWCU phase separator tanks or to the waste surge tanks.
13.
. Discharge path from'each tank to either the waste holdup tanks.or to the mobile solidification system with flow rate indication and throttling capability.
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- 14.
' Capability to transfer contents of each tank to the S ':
other.
15.
Top head and shell manholes for tank maintenance.
16.
Curbs to direct.-leakage or loss of tank contents to "draltis fh ' subsequent containment.
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D.
Response to_GGNS Technical Specification 6.15.(1.d), (1.e),
(1.f), and (1.g).
Q Since this change. involved'only waste storage and transfer considerations'and did not i= pact waste trocercing capabilities or effluent releases; predicted releases of radioactive materials :in liquid and. gaseous effluents and/or solid waste quantities'did not differ as a result of this change. Accordingly, expected caximum exposures to an
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--individual-in the unrestricted area and to the general 4
population were also-unaffected by this change._ Since~this subsystem is. contained within the radwaste building, the potential for radiological consequences due to tank failure is encompassed by the-existing, and still' limiting,-tank failure 3
-analyses presented in the FSAR.
Shielding design of components and routing of associated; piping is consistent with
_the~ design radiation zones-and ALARA principles.
Use of this
' subsystem, with enhanced tank mixing capabilities, will incur an'overall reduction _in exposures to plantioperating personnel
-by-virtue of eliminating the potential for filter sludge
' buildup,~and need for subsequent decontamination'in the tanks
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originally' designed to accommodate this waste-stream.
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-Design Change Package (DCP) -82/607, Modification of the Liquid Radwaste System to Increase Discharge Flow Rate.
A.
Summary of 10CFR'50.59 Considerations The probability of an recurrence or the consequence of an accident, or malfunction of equipment important to safety previously evaluated in the Final Safety Analysis Report was not increased becaust:
The design charge as described below, did not affect a dir2ct safety function or system important to safety, previously evaluated in the FSAR.
Therefore, the probability of an occurrence or the consequence of a malfunction of equipment important to safety was not increased.
The postulated worst case failures (radwaste tank rupture and piping leaks) analyzed in FSAR Sections 15.7.2 and 15.7.3 envelope the occurrence and consequence of postulated accidents due to the discharge isolation valve / sample station relocation described below.
Since this design change did not impact previous design capabilities, predicted releases and exposures did not change.
Therefore, the probability of an occurrence or the consequence of an accident was not increased.
The possibility for an accident or malfunction of a different type than those previously evaluated in the FSAR was not created because:
The discharge isolation valve / sample station design change is located within the radwaste building and designs were developed in accordance with the related guidance in Branch Technical Position ETSB 11-1 of NRC Standard Review Plan 11.2.
Therefore, use of the discharge isolation valve / sample station does not result in releases which differ from those.previously predicted in FSAR Section 15.7.2 and 15.7.3.
The margin of safety, as defined in the basis for the Technical. Specification was not reduced because:
The design change did not change the limiting conditions for operation, applicability, actions, or surveillance requirements as defined in the basis for, Technical Specifications 3/4.11.1, 6.12, 6.13, 6.14, and 6.'15.
B.
Reason for Change Previously, the liquid radwaste system, G17, discharged through flow control valve, F565, and discharge isolation valve, F355.
The discharge isolation valve could only be opened manually with the hand switch.
The valve would close if any of the following conditions occur:
Hand switch turned to "Close".
Cooling tower blowdown flow (Unit 1~and 2) fell below the minimum required for proper dilution of the liquid effluent.
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AE C.'!-E 3 / 0696 Page 5 of 9 The liquid radwaste sample station detected "high" radioactivity in the liquid effluent.
The liquid effluent flowrate exceeded the maximum flow of 35 gpm established for minimum dilution conditions.
The liquid radwaste system, G17, processes large volumes of wastes of very low activity.
The maximum flow limit of 35 gpm on the liquid effluent discharge line unnecessarily limited the ability to discharge this waste.
Additionally, the isolation valve and the sampling point were not optimally located to isolate the liquid effluent released following detection of "high" radioactivity at the sampling point.
C.
Detailed Description of the Change DCP-82/607 provided for the following modifications:
(1) The "high" flow close condition for the isolation valve on the effluent discharge line was changed from 35 gpm to 100 gpm. Appropriate administrative controls will be utilized to determine the effluent discharge flow rate.
The effluent flow rate (0-100 gpm) setpoint will be based on the actual cooling tower (s) blowdown flow available for dilution and the actual activity of the effluent stream as' determined by analysis of the contents of the associated sample tank.
(2) The discharge isolation valve was relocated farther downstream in the 5-inch discharge line, and the discharge sample rack was moved closer to the sample p: f r.t.
This provides a more rapid sample station response time and the ability to isolate the effluent strear 'in the event high radioactivity is detected.
D.
Response to GGNS Technical Specification 6.15, (1.d), (i.e),
(1.f), and (1.g).
This change incorporated the operational flexibility allowed by the station radiological effluent technical specifications by using the Offsite Dose Calculation Manual (ODCM) methodology and parameters to establish alarm and trip setpoints for liquid releases. The predicted releases and exposures to an individual in the unrestricted area and to the-general population, which are presented in the FSAR, demonstrate the capability to meet the requirements of 10CFR 20 and 100FR 50, Appendix I.
Since the change did not impact
. design capabilities, predicted releases and exposures did not change.
Furthermore, this change had no impact on plant operating personnel radiation exposure levels.
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- 3.
Design Change Package (DCP) -83/0028, Installation of a Temporary Radwaste Solidification System
-A.
Summary of 10CFR 50.59 Considerations The probability of an occurrence or the consequence of an accident, or malfunction of equipment important to safety previously evaluated in the Final Safety Analysis Report was no; increased becausc:
The design change as described below, did not affect a direct safety function or system important to safety, previously evaluated in the FSAR. Therefore, the probability of an occurrence or the consequence of a malfunction of equipment important to safety was not increased.
The postulated worst case failures (radwaste tank rupture and piping leaks) analyzed in.the FSAR Sections 15.7.2 and 15.7.3 encompass the occurrence and consequences of postulated accidents due to the design change.
Therefore, the probability of an occurrence or the consequence of an accident was not increased.
The possibility for an accident or malfunction of a different type than any previously evaluated in the Final Safety Analysis Report was not created because: All potentially radioactive portions of the mobile / portable solidification system are located within the radwaste building and designs were developed in accordance with the related guidance in Branch Technical Position ETSB 11-3 of NRC Standard Review Plan 11.~4.
Therefore, use of-the mobile / portable solidification system ioes not result in releases which differ from those_previously predicted in FSAR' Sections 15.7.2 and 15.7.3 nor.will.there be a change to the maximum expcsure to can individual in the unrestricted area.
T..; r,argin of safety, as defined in the basis for any Technical' Specification was not reduced because:
The design change did not change the limiting' conditions for operation, applicability, actions, or surveillance requirements as defined.in the basis for Technical Specifications'3/4.11.3, 6.12, 6.13, and 6.15.
B.
Reason for Change-The vendor which supplied the permanent radwaste solidification ~ system recommended design changes which could notLbe implemented in time -for scheduled startup of the GGNS Unit #1..To support plant operations in.the interim,
~
DCP-83/0028 provided a temporary mobile / portable solidification system.
The~ system, as supplied by a.
contractor, was installed in'the'radwaste building rail / truck bay (Elevation'113'-0", Area 27) to provide solidification services for. receiving, processing, and packaging solid radwaste. lui associated DCP-82/650, which is ~ discussed later, provided' process piping and valves for transferring waste input from the evaporator bottoms tanks, the RWCU phase CE6'
c Attachment tc 3rc"-53/0696 Page 7 of 9 separator and decay tanks, the condensate phase separator tanks, the waste holding tanks, and the spent resin tank to the vendor connection station located in the radwaste building rail / truck bay. DCP-82/650 also provided a vendor decant return line to the RWCU phase separator and decay tanks.
The temporary Mobile Solidification System (MSS), as provided under this DCP-83/0028, interfaces with the vendor connection station.
C.
Detailed Description of the Change The MSS was installed in the radwaste building rail / truck bay.
Operator platforms were provided to provide access to the vendor connection station.
Permanent plant interfaces (service air, service water, electrical, and ventilation) were provided'for the operation of contractor supplied equipment.
The condensate and service air flush lines, inrtalled by DCP-82/650, were interfaced to valve and flange connections to provide service air and water.
Electrical interfaces were supplied for the contractor supplied equipment.
A vent connection from the MSS (located at the vendor connection station) was provided to the radwaste ta.nk ventilation system.
Curbing (encompassing the MSS equipment) is provided to contain the release of radioactive wastes due to line breaks, overflows, or equipment failures. Ramps are provided (approximately 12' in width) across the curbing to permit fork-lift / truck access.
In ccnjunctica with the MSS operation, the licitations on the radwaste overhead crane bridge travel did not provide the required access to the rail / truck bay to permit MSS operation.
The bridge travel was extended by relocation of the bridge travel limit switches and bridge bumper stops to provide the maximum possible access to the radwaste rail / truck bay.
The design changes were, developed in accordance with applicable ALARA guidelines.
D.
Response to GGNS Technical Specification 6.15, (1.d), (1.e),
(1.f), and (1.g).
This. change provided the capability to use mobile solidification equipment in place of the installed solidification system described in the FSAR.
The potentially radioactive portions of the mobile system were located within the radwaste building.
Curbing to contain spills and ventilation interfaces were installed in accordance with the applicable portions of Branch Technical Position ETSB 11-3 of NRC Standard Review Plan 11.4.
Predicted releases of radioactive materials in liquid and gaseous effluents do not differ ~from those previously predicted in the'FSAR.
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AECM-83/06h Page 8 of 9 Furthermore, the predicted quantity of solid waste does not differ from that which was previously predicted in the FSAR.
Accordingly, expected maximum exposures to an individual in the unrestricted area and to the general population are also unaffected by this change.
Since a mobile system inherently requires more personnel contact than the remotely operated, original system described in the FSAR, some additional e::posurc to centractor or plant operating personnel can be anticipated.
Based on information from mobile solidification system contractors and utilizing temporary shielding as necessary, less than 250 mr/ month gross additional exposure is anticipated.
Considering potential deficiencies in the original system and potential maintenance incurred exposures, a net reduction in exposure to plant operating personnel can result from use of a mobile solidification system.
4.
Design Change Package (DCP) 82/650, Radwaste Transfer Lines from Liquid Radwaste to Vendor Connection Station.
A.
Summary of 10CFR 50.59 Considerations The probability of an occurrence or the consequence of an accident or malfunction of equipment important to safety previously evaluate.d in the Final Safety Analysis Report was not increased because:
The design change as described below, did not affect a direct safety function or system important to safety, previously evaluated in the FSAR.
Therefore, the probability of an occurrence or the consequence of a tilfunction of equipment irportant to s:fety was not tineressed.
The postulated verrt case failures (radwaste tank rupture and piping leaks) analyzed in the FSAR Sections 15.7.2 and 15.7.3 enveloped the occurrence and consequence of postulated accidents due to the design change.
Therefore, the probability of an occurrence or the consequence of an accident was not increased.
The possibility for an accident or malfunction of a different Ltype than those previously evaluated in the Final Safety Analysis Report was not created because: All potentially radioactive ' portions of the radwaste transfer line system are
' located within the radwaste building and designs were developed in accordance with the related guidance in Branch Technical Position ETSB 11-1 of NRC Standard Review Plan 11.2.
Therefore, use of the radwaste transfer lines does not result in releases which differ from those previously predicted in FSAR Sections 15.7.2 and 15.7.3 nor is there a change to the maximum exposure to an individual in the unrestricted area.
The margin of safety, as~ defined in the basis for the Technical Specification was not reduced because:
The design change did not change the limiting conditions for operation, CES p
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applicability, action or surveillance requirements as defined n
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in the basis for Technical Specifications 3/4.11.1, 3/4.11.3, j
6.12, 6.13, and 6.15.
3 B.
Reason for Change i
e The vendor, which supplied the permanent radwaste i
solidification system, recommended design changes which could not be implemented in time for schedulec startup cf tne GGNS i
g Unit #1.
To support plant operations in the interim, a 1
7 temporary mobile / portable solidification system, as provided by a contractor, was installed in the radwaste building
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rail / truck bay (Elevation 133'-0", Area 27) to provide
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L solidification services for receiving, processing, and L
packaging solid radwaste. Flexible hoses associated with a j
contractor's portable radwaste solidifcation system required replacement, to the extent possible, with permanently 3
L installed piping using ALARA considerations.
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C.
Detailed Description of Change i
1, 7
This design change package (DCP) required modification of the L
existing solid radwaste (GIS) and liquid radwaste (G17) 3 a
systems such that liquid radwaste could be transferred 1
directly to a vendor processing station in the radwaste
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rail / truck bay.
Waste will be transferred from the evaporator j
5 bottoms tank, the waste holdup tank, the RWCU phase separators, the new Condensate Phase Separator (CPS) tanks, 1
and the spent resin tank.
Further, the system design provided s
r for decantation from vendor equipment to the RWCU phase F-reparators cnd previded service sir and coadensate :c j
5 backflush the effluent lines.
This deci;n change alsc E
i provided for the heat tracing and insulating of the lines from l
E' the waste holding tank and the evascrator bottoms tar.:. to prevent crystallization of waste solids.
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E D.
Response to GGNS Technical Specification 6.15, (1.d), (1.e),
k (1.f), and (1.g).
j I
5 Since this change involved only interface piping for transfer p
of waste and did not impact waste processing capabilities i
e (except to increase flexibility) or effluent releases, i
g predicted releases of radioactive materials in liquid and i_
gaseous effluents and/or solid waste quantities do not differ E
as a result of this change.
Accordingly, expected maximum j
exposures to an individual in the unrestricted area and to the s
general population are also unaffected by this change.
Since all of the transfer piping is contained within the radwaste E
a building, any potential for radiological consequences due to spills is encompassed by the existing tank failure analyses j
presented in the FSAR.
The piping routing design was consistent with the design radiation zones and ALARA 2
principles such that no additional exposure to plant operating e
E personnel resulted from this change.
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