ML051990514

Improved Technical Specifications, Volume 16, Revision 0, ITS Chaper 4.0, Design Features.

ML051990514
Person / Time
Site:	Monticello
Issue date:	06/29/2005
From:	Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML051990514 (20)

Text

IMPROVED TECHNICAL SPECIFICATIONS MONTICELLO NUCLEAR GENERATING PLANT VOLUME 16 ITS Chapter 4.0, Design Features Commhted to Nudear ExcellIv7

Attachment 1, Volume 16, Rev. 0, Page 1 of 19 ATTACHMENT 1 VOLUME 16 MONTICELLO IMPROVED TECHNICAL SPECIFICATIONS CONVERSION ITS CHAPTER 4.0 DESIGN FEATURES Revision 0 Attachment 1, Volume 16, Rev. 0, Page 1 of 19

Attachment 1, Volume 16, Rev. 0, Page 2 of 19 LIST OF ATTACHMENTS

1. ITS Chapter 4.0 Attachment 1, Volume 16, Rev. 0, Page 2 of 19

, Volume 16, Rev. 0, Page 3 of 19 ATTACHMENT I ITS Chapter 4.0, Design Features A6 , Volume 16, Rev. O.Page 3 of 19

Attachment 1, Volume 16, Rev. 0, Page 4 of 19 Current Technical Specification (CTS) Markup and Discussion of Changes (DOCs)

Attachment 1, Volume 16, Rev. 0, Page 4 of 19

K C C 0 ITS Chapter 4.0 ITS 4.0 5.0 DESIGN FEATURES 4.1 5.1 Site ID CD Minnesota 0 4.1.1 A. a reactor ce i fslocated at odxlmate 850,810 feet North and 3620

, feet East as detemined

<fThe eestsite Boun ao mate feet S 30'W of the reactor center Jh~iadh .,

CD exclusion area Isdefined by the minimum fenced area shown In FSAR Figure 2.2.2a. Due to the prevalliwnd pattern, the (A.1 CD PO direction of mnaxnum integrated dosas E. The southern property le ner y follows the no m boundamy of the ri htoof-way for the Burlin ton em Railway. More details on the property Uines can be und In USAR Figure 2.2-1.

0 4.2 5.2 Reactor 34 Add proposed ITS 4.1.2 A M 0

4.2.1 A. The reactor core shall consist of not more than 484 fuel assemblies. Add proposed details of fuel assemblies ED 0' a, 4.2.2 B. The reactor core shall contain 121 cruclform-shaped control rods whose design has been reviewed and approved for BWR use CD by an NRC Safetv Evaluation Report. The control rod material shall be boron carbidelpowder (94) cormnproxima e CD 170% densitylor hafnium.

0 5.3 Reactor Vessel (D A. The a vessel shall be designed for a pre 150 psig and a temperature of 562RF. The cools rLation system CD obedesigned for a pressure of l148 ucioneldeofpump and 1248 psI at pump dis . Theapplicabledesign 3 codes shan be as described in s4.2.3 and 4.3.1 of the Monticello Final Safety An epor.

to U2 CD 5.4 Containment/ CA 0 A. The prima arinment shaebe of the pressure su tyontype having a drywe" and an absorption chd m bered vf 0

-9 steel e drywell shall have a volume of app tely 134,200 03 and Is designed to conform to ASker and Pressure CO 0 2 psIg at 281 F. The

.A.4 ssel Code Section 111 Class B for an in pressure of 56 psg at 281 F and an external pres to absorption chamber shall have aptvolume of approxmately250 176.250 V.

5.0 230 11125/87 Amendment No. 4a, 28, 4 54 Page 1 of 2

C C 0 ITS Chapter 4.0 ITS It Is designed to conform to E Boller and Pressure Vessel Code Ionll Class B for an Internal pressure of 56 psig at 281 'F and an external p sure of 2 psig at 281 "F.

B. Penetrations add the primary containment shall be de ed in accordance with standards set forth In Secti 52.2.3 o Final Safety ysis Report. Piping passing through s penetrations shall have isolation valves in accord ce wih stand set forth iection 5.2.2.4 of the Final Safety Anal Report.

Su C. reactor building, standby gas treatmen tem and stack shall comprise a secondary contai nt in such fashion to 0) w nclose the primary containment in ord o provide for controlled elevated release of the rea r building atmosphere under accIdent conditions. 0 a

CD 0 0 4.3 5.5 Fu~el Storagp, 4.3.1. 2.a, A. I Normal stg e for unirradiated fuel assemblies is In criticallv-A uel 'storae racks In the reactor building stora ult. ) C 0

4.3.1. 2-b). Fuel shall be stored in arrays such that the Keff dry Is less than 0.90 and flooded is less than 0.95. Inorder to meet these limits, 4.3.1., ?.C new fuel assemblies shall have an Infinite lattice multiplication factor less than or equal to 1.31.

< Ad rpse T 4.3.1.2.d and ITS4..:: 3) 0 0) 4.3.1.1 .a, B. The Keff of the spent fuel storage pool shall be less than or equal to 0.95. In order to meet this limit, fuel assemblies stored In F 4.3.1.1 .b this pool shall have an infinite lattice multiplication factor less than or equal to 1.33. [Add proposed ITS 4.3.1.1.c and ITS 4.3.1.1.d M.4 0 a

5CD 5.6 Seismic Design 0)

-L All Class I stares and equipment were analyzed to tha safe shutdown can be made during gro n of 0.12g (Ma Earthquake). Dynamic analysis wa o determine the earthquake acceleration applic e various elevations In - >

-U

.. th-e reactor building.

Q am t)

CD (0 0) 0)

0D CD Add proposed ITS 4.3.2 4

Y DM (0 t

proposed I I S 4.3.J 1 l

i \

D3 5.0 231 10/8/85 Amendment No. 34 Page 2 of 2

Attachment 1, Volume 16, Rev. 0, Page 7 of 19 DISCUSSION OF CHANGES ITS CHAPTER 4.0, DESIGN FEATURES ADMINISTRATIVE CHANGES A.1 In the conversion of the Monticello Current Technical Specifications (CTS) to the plant specific Improved Technical Specifications (ITS), certain changes (wording preferences, editorial changes, reformatting, revised numbering, etc.) are made to obtain consistency with NUREG-1433, Rev. 3, "Standard Technical Specifications General Electric Plants, BWR/4" (ISTS).

These changes are administrative changes and are acceptable because they do not result in technical changes to the CTS.

MORE RESTRICTIVE CHANGES M.1 CTS 5.1 does not specify the boundary requirements for the low population zone.

ITS 4.1.2 states that the low population zone is all the land within a one mile radius circle as shown in Chapter 15, Figure ND-95208 of the USAR. This changes the CTS by specifying the additional Design Feature for the Low Population Zone.

The purpose of ITS 4.1.2 is to specify the low population zone. ITS 4.1.2 specifies the low population zone required for the radiological considerations of 10 CFR 100. This change is acceptable because it identifies an additional design feature required in assuring radiological doses from postulated accidents will be acceptably low. This change is more restrictive because the ITS specifies a Design Feature not specified in the CTS.

M.2 CTS 5.2.A states that the reactor core shall consist of not more than 484 fuel assemblies. ITS 4.2.1 contains a similar statement but provides a description of acceptable assemblies. This changes the CTS by specifying the types of fuel assemblies that can be placed into the reactor core.

The purpose of CTS 5.2.A is to limit the number of fuel assemblies that can be loaded into the core. ITS 4.2.1 continues to provide this limitation, but it also describes acceptable fuel assemblies. Specifically, each assembly shall consist of a matrix of Zircalloy fuel rods with an initial composition of natural or slightly enriched uranium dioxide (U02) as fuel material and water rods. Some fuel rods may consist of a Zircalloy base and a zirconium inner liner. Fuel assemblies shall be limited to those fuel designs that have been analyzed with NRC staff approved codes and methods and have been shown by tests or analyses to comply with all safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions. This change is acceptable because the description of the fuel assemblies is consistent with the USAR description. This change is more restrictive because a description is provided that limits the type of fuel assemblies that can be loaded into the core.

M.3 CTS 5.5.A does not specify the required keff for the new fuel storage when moderated under optimum moderator conditions and does not specify the center to center distance between fuel assemblies in the new fuel storage racks.

ITS 4.3.1 .2.d specifies the kefr value under optimum moderator conditions and Monticello Page 1 of 5 Attachment 1, Volume 16, Rev. 0, Page 7 of 19

Attachment 1, Volume 16, Rev. 0, Page 8 of 19 DISCUSSION OF CHANGES ITS CHAPTER 4.0, DESIGN FEATURES ITS 4.3.1 .2.e specifies a minimum center to center distance between fuel assemblies placed in storage racks. This changes the CTS by specifying two additional design features for the new fuel storage rack that do not currently exist.

The purpose of ITS 4.3.1.2.d is to specify a value for kff under optimum moderator conditions. The purpose of ITS 4.3.1.2.e is to specify a minimum center to center distance between fuel assemblies placed in the storage racks.

This change is acceptable because the values are consistent with the current limits analyzed in the USAR. Also, this change is consistent with the requirements of 10 CFR 50.36 to specify design features of the facility which, if altered or modified, would have a significant effect on safety and is not covered in any other Technical Specification. This change is more restrictive because the ITS specifies design features not specified in the CTS.

M.4 CTS 5.5.B does not specify the ketf value for the original fuel rack if fully flooded with unborated water and does not specify the spacing requirements for the fuel assemblies in the original or high density spent fuel storage racks. ITS 4.3.1.1 .c state the value of keff for the original fuel rack if fully flooded with unborated water and ITS 4.3.1.1.d specifies the spacing requirements of the fuel assemblies within the storage racks and the spacing requirements between the two types of storage racks. This changes the CTS by specifying two additional design features for the spent fuel storage racks that do not currently exist.

The purpose of ITS 4.3.1.1 .c is to limit the ken for the original fuel rack if fully flooded with unborated water. The purpose of ITS 4.3.1.1.d is to specify the spacing limits for fuel assemblies placed in the storage racks. This change is acceptable because it provides values consistent with the current limits assumed in the USAR. Also, this change is consistent with the requirements of 10 CFR 50.36 to specify design features of the facility which, if altered or modified, would have a significant effect on safety and is not covered in any other Technical Specification. This change is more restrictive because the ITS specifies design feature not specified in the CTS.

M.5 CTS 5.0 does not specify the elevation to which, by design, the spent fuel storage pool could be inadvertently drained. ITS 4.3.2 specifies the elevation that the spent fuel storage pool could be inadvertently drained to due to design.

This changes the CTS by specifying the additional design feature for the spent fuel storage pool inadvertent drainage level.

The purpose of ITS 4.3.2 is to specify the elevation that the spent fuel storage pool could be inadvertently drained to due to design. This change is acceptable because it specifies the lowest elevation to which the spent fuel storage pool can be drained with the gates not installed (which is the normal condition of the spent fuel storage pool during refueling operations). At the lowest design elevation, the fuel will remain'covered as required by Regulatory Guide 1.13, Revision 1. This change is more restrictive because the ITS specifies a design feature not specified in the CTS.

M.6 CTS 5.0 does not specify the spent fuel storage pool design capacity limitations for fuel assemblies. ITS 4.3.3 specifies that the spent fuel storage pool is Monticello Page 2 of 5 Attachment 1, Volume 16, Rev. 0, Page 8 of 19

Attachment 1, Volume 16, Rev. 0, Page 9 of 19 DISCUSSION OF CHANGES ITS CHAPTER 4.0, DESIGN FEATURES designed and shall be maintained with a storage capacity limited to no more than 2237 fuel assemblies. This changes the CTS by specifying the additional design feature for the spent fuel storage pool fuel assembly capacity.

The purpose of ITS 4.3.3 is to specify the design fuel assembly capacity limit of the spent fuel storage pool. This change is acceptable because it specifies the maximum design capacity for fuel assemblies in the spent fuel storage pool.

Also, this change is consistent with the requirements of 10 CFR 50.36 and specifies a design feature of the facility which, if altered or modified, would have a significant effect on safety and is not covered in any other Technical Specification. This change is more restrictive because the ITS specifies a design feature not specified in the CTS.

RELOCATED SPECIFICATIONS None REMOVED DETAIL CHANGES LA.1 (Type 1 - Removing Details of System Design and System Description, Including Design Limits) CTS 5.1 provides details describing the site location and property lines. The ITS does not contain these details. This changes the CTS by moving the details of the site location and property to the USAR.

The removal of these details, which are related to the site location and the site and exclusion area boundaries, from the Technical Specifications, is acceptable because this type of information is not necessary to be included in the Technical Specifications to provide adequate protection bf public health and safety.

ITS 4.1.1 retains the Design Features of the site and exclusion area boundaries.

Also, this change is acceptable because the removed information will be adequately controlled in the USAR. Any changes to the USAR are made under 10 CFR 50.59 or 10 CFR 50.71(e), which ensures changes are properly evaluated. This change is a less restrictive removal of detail change because information relating to system design is being removed from the Technical Specifications.

LA.2 (Type 1- Removing Details of System Design and System Description, Including Design Limits) CTS 5.2.B states that the control rod material shall be boron carbide 'powder (B4 C) compacted to approximately 70% of theoretical density" or hafnium. ITS 4.2.2 states the control material shall be boron carbide or hafnium metal as approved by the NRC. This changes the CTS by moving the detailed description of the boron carbide control rod material to the USAR.

The removal of these details, which are related to system design, from the Technical Specifications is acceptable because this type of information is not necessary to be included in the Technical Specifications to provide adequate protection of public health and safety. The ITS still retains requirements on boron carbide control rod material. Also, this change is acceptable because the Monticello Page 3 of 5 Attachment 1, Volume 16, Rev. 0, Page 9 of 19

Attachment 1, Volume 16, Rev. 0, Page 10 of 19 DISCUSSION OF CHANGES ITS CHAPTER 4.0, DESIGN FEATURES removed information will be adequately controlled in the USAR. Any changes to the USAR are made under 10 CFR 50.59 or 10 CFR 50.71(e), which ensures changes are properly evaluated. This change is a less restrictive removal of detail change because information relating to system design is being removed from the Technical Specifications.

LA.3 (Type 1 - Removing Details of System Design and System Description, Including Design Limits) CTS 5.3 includes some design details of the reactor pressure vessel and the reactor recirculation system. The ITS does not contain this information. This changes the CTS by moving the description of the design details of the reactor pressure vessel and the reactor recirculation system to the USAR.

The removal of these details, which are related to system design, from the Technical Specifications is acceptable because this type of information is not necessary to be included in the Technical Specifications to provide adequate protection of public health and safety. The ITS still retains requirements on reactor pressure vessel and the reactor recirculation system in ITS Section 3.4.

Also, this change is acceptable because the removed information will be adequately controlled in the USAR. Any changes to the USAR are made under 10 CFR 50.59 or 10 CFR 50.71(e), which ensures changes are properly evaluated. This change is a less restrictive removal of detail change because information relating to system design is being removed from the Technical Specifications.

LA.4 (Type I - Removing Details of System Design and System Description, Including Design Limits) CTS 5.4 describes the various design features of the primary and secondary containments. The ITS does not contain this information. This changes the CTS by moving the description of the design feature of the containment to the USAR.

The removal of these details, which are related to system design, from the Technical Specifications is acceptable because this type of information is not necessary to be included in the Technical Specifications to provide adequate protection of public health and safety. The ITS still retains requirements on primary and secondary containments OPERABILITY in ITS Section 3.6. Also, this change is acceptable because the removed information will be adequately controlled in the USAR. Any changes to the USAR are made under 10 CFR 50.59 or 10 CFR 50.71(e), which ensures changes are properly evaluated. This change is a less restrictive removal of detail change because information relating to system design is being removed from the Technical Specifications.

LA.5 (Type I - Removing Details of System Design and System Description, Including Design Limits) CTS 5.5.A states, in part, that normal storage for unirradiated fuel assemblies is in critically-safe new fuel storage racks in the reactor building storage vault. The ITS does not contain this information. This changes the CTS by moving the detail of the location where normal storage for unirradiated fuel assemblies is stored to the USAR.

Monticello Page 4 of 5 Attachment 1, Volume 16, Rev. 0, Page 10 of 19

Attachment 1, Volume 16, Rev. 0, Page 11 of 19 DISCUSSION OF CHANGES ITS CHAPTER 4.0, DESIGN FEATURES The removal of these details, which are related to system design, from the Technical Specifications is acceptable because this type of information is not necessary to be included in the Technical Specifications to provide adequate protection of public health and safety. The ITS still retains requirements for keff and k-infinity for the storage of new fuel. Also, this change is acceptable because the removed information will be adequately controlled in the USAR.

Any changes to the USAR are made under 10 CFR 50.59 or 10 CFR 50.71 (e),

which ensures changes are properly evaluated. This change is a less restrictive removal of detail change because information relating to system design is being removed from the Technical Specifications.

LA.6 (Type I - Removing Details of System Design and System Description, Including Design Limits) CTS 5.6 describes certain general seismic design requirements for Class 1 structures and equipment. The ITS does not contain this information.

This changes the CTS by moving the description of these general seismic design requirements to the USAR.

The removal of these details, which are related to system design, from the Technical Specifications is acceptable because this type of information is not necessary to be included in the Technical Specifications to provide adequate protection of public health and safety. The ITS still retains OPERABILITY requirements for various Class 1 structures, systems, and components. Also, this change is acceptable because the removed information will be adequately controlled in the USAR. Any changes to the USAR are made under 10 CFR 50.59 or 10 CFR 50.71(e), which ensures changes are properly evaluated. This change is a less restrictive removal of detail change because information relating to system design is being removed from the Technical Specifications.

LESS RESTRICTIVE CHANGES None Monticello Page 5 of 5 Attachment 1, Volume 16, Rev. 0, Page 11 of 19

Attachment 1, Volume 16, Rev. 0, Page 12 of 19 Improved Standard Technical Specifications (ISTS) Markup and Justification for Deviations (JFDs)

Attachment 1, Volume 16, Rev. 0, Page 12 of 19

Attachment 1, Volume 16, Rev. 0, Page 13 of 19 Design Features 4.0 5.0 4.0 DESIGN FEATURES 5.1 4.1 Site Location 5.1 A I[ Text descrip jofsite locatior i. -. (

-1 5.2A 4.2 Reactor Core 5.2A 4.2.1 Fuel Assemblies 4 -7 5.2A The reactor shall contain fuel assemblies. Each assembly shall consist of a matrix of Zircalloy o Lfuel rods with an initial composition of natural or '

slightly enriched uranium dioxide (UO2 ) as fuel material and iwater rods3. Limited J {

ubstitution o zirconiumalloy orst inlesssteel illerrods tor uel ro in ccordanc with approved appli ons of fuel rod configurations. ma be used[INSERT 2 Fuel assemblies shall be limited to those fuel designs that have been analyzed with NRC staff approved codes and methods and have been shown by tests or analyses to comply with all safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions.

5.2.B

• 4.2.2 Control Rod Assemblies - Et7 5.2.6 The reactor core shall contain 1 cruciform shaped control rod assemblies.

The control material shall begboron carbidediafnium metaQ as approved by the 0D NRC.

s.s 4.3 Fuel Storage 5.5.B 4.3.1 Criticality 5.5.B 4.3.1.1 The spent fuel storage racks are designed and shall be maintained with: ~. E 6.5.B a. Fuel assemblies having a maximumrik-infinity of 1 in the normal reactor core configuration at cold condition a e 0 I U-235 enrimatomfj4Tweight percentag kef"~09_ for ~high d~ensity fuel ~racks} m 5.5.6 b. kl

• 0.9 if fully flooded with unborated water, which includes an U allowance for uncertainties as described insection iJf t 2 )e DOC M.4 4MSA 4,i3 t3i DOC M.4 . A nominal[.5 inc center to center distance between fuel (E)ix J assemblie ced in th storage ra ck  ;

hig hdens_

5.5.A 4.3.1.2 The new fuel storage racks are designed and shall be maintained with:

BWR/4 STS 4.0-1 Rev. 3.0, 03/31/04 Attachment 1, Volume 16, Rev. 0, Page 13 of 19

Attachment 1, Volume 16, Rev. 0, Page 14 of 19 4.0 Q INSERT 1.

4.1.1 Site and Exclusion Area Boundaries The site area and exclusion area boundaries are as shown in Chapter 15, Figure ND-95208 of the USAR.

4.1.2 Low Population Zone The low population zone is all the land within a I mile radius circle as shown in Chapter 15, Figure ND-95208 of the USAR.

Q INSERT 2 Some fuel rods may consist of a Zircalloy base and a zirconium inner liner.

Q0 INSERT3

c. kef

• 0.90 for original fuel rack if fully flooded with unborated water, which includes an allowance for uncertainties as described in Section 10.2.1 of the USAR; and Q INSERT 4 a 6.625 center to center distance between fuel assemblies placed in the original storage rack, and a two inch gap between the high density racks and the original rack.

Page 4.0-1 Attachment 1, Volume 16, Rev. 0, Page 14 of 19

Attachment 1, Volume 16, Rev. 0, Page 15 of 19 Design Features 4.0 CTS 4.0 DESIGN FEATURES 5.5 4.3 Fuel Storage (continued)

a. Fuel assemblies having amaximumk-infinityofRI.3l0inthe 1 5.5.A normal reactor core configuration at cold conditionDIas l 1 I U-235 enri . weight percenta 5.5.A 5.5A .kff g 0.95 if fully flooded with unborated water, which includes an allowance for uncertainties as described inASection bf the (.)

lunderoptimum moderator conditions 4 DOC M.3 -fh. kif

• 0.98 if moderate ueous foam, which includes an allowance for uncertainties as described in ISection o-f theio i i)

@F*SAFj land 2 DOC M.3 E. A nin.0 inccenter to center distance between fuel ( O assemblies placed in storage rack>..

DOC M.5 4.3.2 Drainage The spent fuel storage pool is designed and shall be maintained to prevent inadvertent draining of the pool below elevation ft]l. 0 K-, DOC M.6 4.3.3 Capacity The spent fuel storage pool is designed and shall be maintained with a storage capacity limited to no more than fuel assemblies. 0 BWR/4 STS 4.0-2 Rev. 3.0, 03/31/04 Attachment 1, Volume 16, Rev. 0, Page 15 of 19

Attachment 1, Volume 16, Rev. 0, Page 16 of 19 4.0 0 INSERT 5

b. keff < 0.90 if dry; 0 INSERT 6 within a row and a minimum 10 inch center to center distance between fuel assemblies placed in storage racks between rows Page 4.0-2 Attachment 1, Volume 16, Rev. 0, Page 16 of 19

Attachment 1, Volume 16, Rev. 0, Page 17 of 19 JUSTIFICATION FOR DEVIATIONS ITS CHAPTER 4.0, DESIGN FEATURES

1. The brackets have been removed and the proper plant specific information/value has been provided.

2. These punctuation corrections have been made consistent with the Writers Guide for the Improved Standard Technical Specifications, NEI 01-03, Section 5.1.3.

3. ISTS 4.3.1.1.b (ITS 4.3.1.1.b) has been revised to clarify that the value for keff is for high density fuel racks and ITS 4.3.1.1 .c has been added to reflect the keff value for the original fuel racks. This is consistent with USAR Section 10.2.1.2. Subsequent Specifications have been renumbered to reflect this change. In addition, ISTS 4.3.1.1.c (ITS 4.3.1.1.d) has been modified to reflect the appropriate distance for both types of fuel racks.

4. ITS 4.3.1 .2.b has been added to include the new fuel storage requirement for Kff if the vault is dry, consistent with current licensing basis. Subsequent Specifications have been renumbered to reflect this change. In addition, ISTS 4.3.1.2.c (ITS 4.3.1.2.b) has been modified to provide the current licensing basis keff limit and to delete the specific type of moderation (i.e., aqueous foam) and replace it with a more generic term (i.e., under optimum moderator conditions), consistent with the USAR analysis.

5. The fuel assembly description has been modified to be consistent with the USAR.

Monticello Page 1 of I Attachment 1, Volume 16, Rev. 0, Page 17 of 19

Attachment 1, Volume 16, Rev. 0, Page 18 of 19 Specific No Significant Hazards Considerations (NSHCs)

Attachment 1, Volume 16, Rev. 0, Page 18 of 19

Attachment 1, Volume 16, Rev. 0, Page 19 of 19 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATIONS ITS CHAPTER 4.0, DESIGN FEATURES There are no specific NSHC discussions for this Specification.

Monticello Page 1 of 1 Attachment 1, Volume 16, Rev. 0, Page 19 of 19