ML13333B130

Second Surveillance Rept for SONGS Unit 1 Intake Structure (Cycle X Refueling Outage)

ML13333B130
Person / Time
Site:	San Onofre
Issue date:	03/13/1989
From:	Miller R Southern California Edison Co
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ML13333B129	List: ML13333B128 ML13333B130 ML13333B131
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NUDOCS 9008240045
Download: ML13333B130 (75)

Text

SECOND SURVEILLANCE REPORT FOR SONGS UNIT 1 INTAKE STRUCTURE (CYCLE X REFUELING OUTAGE)

SOUTHERN CALIFORNIA EDISON COMPANY APPROVED BY:

AUTHOR DATE ENG INQ fkGROUPLEADER DATE S PE DATE SUPRVISING CIVIL E GINEER DATE 900:3240045 9:008:-,14 PDR ADOC-K 05000206 p

PDC

Page 2 EXECUTIVE

SUMMARY

SCE has committed to the NRC that the Unit 1 intake structure will be inspected every refueling outage in accordance with the NRC approved surveillance program.

As a part of this surveillance program, the struc ture was inspected in 1986, and the '1 Report of First Surveillance for SONGS Unit 1 Intake Structure (Cycle IX)"1, dated May 1986, is on file.

The intake structure was reinspected in December 1988. The latter inspection results indicate that the corrosion process continues and differs in portions of the structure. It was determined based on the inspection and evaluation of structural margins that the structure maintains its ability to withstand a 0.67g Modified Housner seismic event. However, to ensure the future ability of the structure to maintain its integrity, a crossover section of

-the north wall (approximately 1O'x9' high) was recommended to be repaired because of the numerous indications of corrosion that appeared since the previous inspections. The repair will ensure the continued structural integrity of the intake structure and its ability to withstand a design seismic event until at least the Cycle XI surveillance.

Page 3 TABLE OF CONTENTS Page No.

1.0 Introduction 4

2.0 Visual Observations 5

3.0 Half-Cell Measurements 10 4.0 Structural Evaluations 11 5.0 Repairs 13 6.0 Conclusions 14 7.0 References 15 Appendices A. Visual Observation Field Notes First Surveillance Second Surveillance B.

Silver-Silver Chloride Half-Cell Measurements Drawings C.

Visual Inspection Drawings

Page 4

1.0 INTRODUCTION

The intake structure is a reinforced concrete structure which provides the structural transition from the pipes that collect and discharge sea water for condenser cooling and safety related salt water cooling. The intake structure also supports the safety related salt water cooling pumps.

In June 1984, exposed reinforcing steel bars and local concrete spalls were found at the north stop gate slot.

Subsequent dewatering and inspection of the intake structure showed that some of the reinforcing steel near the concrete surfaces in cotact with sea water were corroded. In order to define the extent of corrosion and its effect on the structure, a coring and chipping program was undertaken. Additional tests and examinations performed had included half-cell testing, petrographic examinations, and chemical testing for chloride content. The investigation concluded that a repair program was required.

The repair program included bolting strap plates to designated areas of the screen and pump wells. Design of the plates was based on the conservative assumption that the inside reinforcement was non-existent in the repaired areas. The strap plates were prdtected against corrosion with a coal tar epoxy coating and sacrificial zinc anode cathodic protection.

The investigation and evaluation of the structure established that intrusion of chloride ions was the cause of the structural deterioration, which had primarily occurred to the interior reinforcing steel in the screen well areas of the structure. It was also concluded that the condition of the structure would be monitored through a regular surveillance program. For details of the evaluation and repair, see Reference 1.

In February-May 1986, the First Surveillance (Cycle IX refueling outage) was performed as committed to by SCE based on the guidelines approved by the NRC (References 5 and 6). The surveillance is documented in Reference

2. It was found that the repairs of 1984 were in very good condition. The inspection of 1986 revealed that the corrosion process was continuing. The only new concentration of rust spots was found on the northeast section of the intake tunnel ceiling approaching the screen well. During the interval between the 1984 and 1986 inspections the quantity of corrosion products was not as extensive as observed in 1984 which indicated that the corrosion process was not progressing rapidly.

The 1986 inspection also indicated a lack of systematic corrosion.

Page 5 1.1 The purpose of this report is to document the results of the surveillance activities which were performed in December 1988 (Cycle X refueling outage).

1.2 SCOPE In preparation for the surveillance activities the unrepaired concrete structural elements (those areas not repaired in 1984) of the intake structure were reevaluated to determine reinforcement requirements to maintain the operability of the safety related salt water cooling system during a DBE. The areas evaluated were the north and south walls of the intake tunnel including the ceiling, screen well walls, concrete beams, and the transition portion. All other areas were either repaired in 1984 with strap plates or classified as Quality Class NSR because their failure would not affect the 4% minimum salt water flow to the salt water cooling pumps. The analysis identified the portions of walls and ceilings that would require repair if the rebars are corroded beyond acceptable limits, and the areas where the concrete strength without inside face rebar is sufficient (Calculation ISR-CC-01). The areas of potential repair (Figure 1) included the north wall between the stop gate slot and the recirculation gate MOV-9, the ceiling between MOV-9 and the turning vanes, the lower portion of the east screen well, and the north and south walls of the upper screen well areas.

The repair for the above areas was designed based on the conservative assumption that the layer of rebars closest to salt water (inside face) was completely corroded and the concrete cover was delaminated. Repair details are shown in DCP 1-3440.OBC and DCP 3078.01BC.

The surveillance of the intake structure consisted of underwater visual inspection and half-cell measurements with silver-silver chloride half-cell using divers. The surveillance was conducted in accordance with Station Maintenance Procedures (References 7 and 8). The surveillance activities concentrated on the areas of potential repair where more detailed inspections were performed with hydroblasting and hammer tapping.

2.0 VISUAL OBSERVATIONS The visual observations recorded the evident signs of corrosion in the intake structure. The visual observations were documented on the Visual Inspection drawings in Appendix C. The numbered circles on the drawings correspond to the First Surveillance Visual Observations Field Notes with numbers 1 through 141,

REPAIRS ARE NEEDED OC AREA REPAIRED IN 1989 REB MORET D50%

mov-9SCREEN WELL STOP GATE CIRCULATING WATER PUMP SCREEN WASH PUMP SALT WATER COOLING PUMP I INTAKE REPAIRS ARE NEEDED IF MORE THAN 25%

REBARS CORRODED PUMP WELL ELEVATION INTAKE STRUCTURE Legend

-AREA THAT M4AY mL NEED REPAIRS

Page 7 and the numbered squares correspond to the Second Surveillance Visual Observation Field Notes with Notes are given in Appendix A. The visual observations were-used as the primary basis for determining the extent of material deterioration (concrete and reinforcing steel).

The visual inspection of the intake structure was conducted underwater by divers. The divers were directed by SCE and Bechtel engineering personnel via a remote video monitor. The inspection was documented on videotapes as well.

The 1984 repaired areas and the areas where the layer of rebars closest to seawater could corrode without compromising the structural integrity of the intake structure were inspected for major deficiencies such as exposed rebars and deep concrete spalls. The strap plates were inspected for integrity of the coating, presence of corrosion products, condition of the anodes, and tightness of the nuts.

The visual examination identified characteristics similar to those observed in 1986 such as small rust spots, shallow spalls, localized concrete surface discoloration and staining. With one exception, as discussed below, there was no evidence of any increase in the size of the rust spots which were described in the previous inspections (1984 and 1986). Corrosion indications were not uniform throughout the intake structure and varied from one area to another without any discernible pattern.

The only substantial increase in the number of rust spots was observed on the north wall crossover between the stop gate slot and the MOV-9 recirculation gate slot (above Elevation (-)

11'). This area exhibited heavy staining in combination with rust spots and two hollow sounding areas. This portion of the wall was not sounded in 1986 because hammer sounding of concrete elements is not required by the surveillance procedures and the number of indications on the wall was insignificant. Since almost no corrosion products were observed in 1986, it is concluded that the hollow sounding areas are largely due to progressive rebar corrosion and subsequent delamination of the concrete cover. The north wall crossover was analyzed to determine its structural capacity without rebars.

The moment capacity of the wall without rebars was determined to be less than the moment produced by the design loading conditions ( M utimate = 8.18 k-ft

< M actual = 8.65 k-ft). Since the uture possibility of rebar loss exists in this area, the wall was

Page 8 repaired with strap plates in January 1989. The repair is similar to the repair program perforemed in 1984 during the Return to Service effort. Seific underwater repair details are given in DCP 1-3440.OBC.

2.1 UNDERWATER VISUAL OBSERVATIONS Nort-h Screen -Well The north wall and the south wall (intermediate wall between screen wells) were repaired with the strap plates in 1984. The strap plates extend up to approximate Elevations (-)

10' and (-)

4' respectively.

In 1986, numerous rust spots with discoloration of concrete were observed on the nortA wall to spread randomly over the surface of the wall, mostly in its lower portion within the previously repaired area.

During the second surveillance inspection in 1986 several new rust spots were found in the lower portion of the wall adjacent to and above the strap plates. No signs of delamination were noticed. Two spalled areas in the middle section of the wall were found. The depth of the spalls does not exceed 1/8. The spalled areas approximately coincide with areas chipped and repaired in 1984.

Approximately 10 new rust spots were found on the intermediate wall, seven of them are located above the existing strap plates and were randomly located.

However, for the intermediate wall the calculated moments are smaller than the unreinforced moment capacity of the wall. Therefore, its structural integrity is not compromised.

All the strap plates in the north screen well showed no sign of distress. The nuts attaching the strap plates to the anchor bolts were checked for looseness. None of the nuts could be turned by hand. The coal tar epoxy coatings were not damaged and no corrosion products were observed. Anodes showed little corrosion and are acceptable.

East wall of the screen well was inspected and three rust spots and one strip of reddish brown rust were found underwater. No signs of delamination were present.

West wall of the screen well was not inspected in detail because the calculated moments for this wall are less than the unreinforced concrete moment capacity. No major deficiencies were noticed on the wall. Therefore, its structural integrity is not compromised.

Page 9

South Screen Well The south wall ard the north wall (intermediate wall between screen wells) have strap plates up to approximate Elevations (-)

6' and (-)

4 respectively only one new rust spot on the southwall with a hollow sounding area around it was found near the abandoned pump stop gate slot. The area was repaired with the strap plates in 1984. The rust spot coupled with the hollow sounding area is not a structural concern because the existing strap plates repairs do not rely on the internal layer of rebars and concrete cover.

On the intermediate wall a number (approximately 17) of new rust spots and small cracks were found. Most of these deficiencies are concentrated along the abandoned pump stop gate slot and the traveling screen slot on the line of a concrete construction joint. However, the calculated moments for the intermediate wall are smaller than the unreinforced moment capacity.

Therefore, its structural integrity is not compromised.

North and South Pump Bays The walls and the ceiling of the pump bays were repaired with the strap plates in 1984. The strap plates, bolts, nuts, and coating showed no ej~gns of distress or deficiencies. The pump bays showed a few new rust spots which were randomly located. Overall, the pump bays showed little change from the previous surveillance.

Transition Section As in 1986, this portion of the structure was accessible for inspection. The two old diagonal cracks and minor spalling on the floor which were observed in 1986 showed no further deterioration.

Tsunami Gate Structure The roof of the tsunami gate structure shows signs of continued rusting of the sheet metal which was used for forming the concrete slab.

CrosoeSeto The inspection was performed on the intake tunnel and discharge sides of the crossover. The north wall has two hollow sounding areas (one area is 4 feet in diameter and the other is 2 feet high by 5 feet long),

several rust spots and a crack. During the 1986 surveillance, this area of the wall was not sounded and only three rust spots were observed. All these

Page 10 indications in combination with rust'staining on the wall indicate possible rebar corrosion and concrete cover delamination. This area had signs of accelerated deterioration.

The crossover tunnel was also inspected but not videotaped because it is a non-safety related portion of the structure. A number of rust spots were observed on the walls of the non-safety related tunnel. The overall condition of the tunnel is satisfactory.

MOV-9 No major deficiencies were found in the gate slot.

Intake Tunnel between Tsunami Gate Slot and Screen Well The north wall of the intake tunnel below the crossover area showed five new randomly located rust spots with exuding rust products and a crack along the recirculation gate slot in addition to two rust spots which were found in 1986. This area was hydroblasted for closer inspection. However, no additional indications were found. The area sounded as solid concrete. The portion of the north wall between the recirculation gate MOV-9 and the screen well showed no signs of further corrosion.

on the south wall between the tsunami gate slot andthe screen well the divers observed no substantial indications of continued corrosion and no spalls.

The ceiling of the intake tunnel was cleaned from marine growth by hydroblasting and showed no new rust spots or any other signs of concrete deterioration.

Flow vanes were briefly inspected and no major deficiencies were noticed by the divers.

3.0 HALF-CELL MEASUREMENTS 3.1 General Since the First Surveillance performed in 1986, the half-cell measurement procedure was revised and the spacing between the grid points was increased from 4' to 8' (Reference 7). The spacing was increased with the provision that additional measurements would be taken in the areas where the readings differed by more than

0. lv.

During the Second Surveillance only silver-silver chloride half-cells were used underwater by the divers.

Page I No copper-copper sulphate half-cells were used for the dewatered areas of the screen wells.

All the half-cell measurements were performed with the Plant Cathodic Protection System shut of f.

3.2 Half--Cel Measuemnt The half-cell readings obtained in 1988 were generally more negative than those recorded in 1986 when the plant cathodic protection system was shut off (the readings differed on the average of between 0.05v and 0.15v). The readings were also more negative towards the transition and the east wall of the pump well and lower in the screen well. As in 1986 the readings were more negative (absolute value) near the bottom of the structure. It was noticed that though the cathodic protection system was shut offt the readings taken several days apart in the same or adjacent areas shifted. The reference half-cell readings also varied and are noted in Appendix B. The reference half-cell readings were taken in the vicinity of the stop gate slot by the intermediate wall in the north screen well.

Thus, the readings were biased by some external source.

The half-cell readings were taken to determine the areas of highest potential for rebar corrosion and also to attempt to establish a correlation between the half cell readings and the rebar corrosion rate. A review of the data and the comparison with similar data obtained in 1986 have failed to produce any trends of corrosion or to detect any localied areas of greater than normal corrosion. The obtained data is inconclusive and was not used during the structural evaluation of the intake structure.

The half-cell readings at the Unit 1 intake structure are not a reliable tool for indicating areas with a higher probability for corrosion. The pattern of half cell readings does not correlate with the areas where an increase in the number of corrosion indications was observed during visual inspection. Since the readings do not provide any reliable data, the half-cell readings should be discontinued for future surveillances of the intake structure.

4.0 STRUCTURAL EVALUATION 4.1 Introduction Prior to the Second Surveillance the areas of the intake structure, which were not repaired in 1984 during the Return to Service effort, were evaluated for their moment capacity. The areas described in Section

Page 12 1.2 were determined to require repairs if the rebars had corroded beyond their acceptable limits.

4.2 Methods Employed The intake structure was evaluated as a part of the Balance of Plant Seismic Reevaluation Program (Reference 1). The results of those analyses form the basis of the design loads in the structure.

The moment capacity of the structural concrete elements was calculated (Reference 9) assuming various rebar percentages, such as 100%, 75%, 50%, 25%, and 0%. (A rebar is considered acceptable if less than 5% of the rebar cross-sectional area is corroded with no concrete delamination.) The reinforced concrete elements were conservatively evaluated using one-way slab analysis.

In addition, the moment capacity of the uncracked concrete section was calculated. Those moment capacities were then compared with the design moments in their respective areas of the intake structure. For each of the areas, the maximum moment for the governing design condition from the Seismic Reevaluation Program was used. These values formed the basis for determining the structure's integrity because they represent the most severe condition to which the structure will be subjected under operating or DBE conditions.

si Results Obtained It was determined that the areas shown in Figure 1 may require repairs based on the evaluation of the structural margins. In addition, Figure 1 shows the percentages of reinforcement area required. The other evaluated areas do not require steel reinforcement at the concrete face exposed to seawater.

The crossover area of the north wall above Elevation

(-)

111-011 was additionally reanalyzed as a two-way unreinforced concrete wall. This evaluation was performed because potentially excessive rebar deterioration was observed. The moment capacity of the wall without rebars was determined to be less than the moment produced by the postulated design loading conditions (8.18 k-ft < 8.65 k-ft). Since the future possibility of excessive rebar loss in this area exists, this area was recommended to be repaired. The north wall crossover was repaired per DCP l-3440.OBC with two horizontal strap plates. The repairs were performed in January 1989. The repairs are similar to the strap plate repair performed in 1984.

The lower portion (between Elevations (-)21-311 and

Page 13

(-) 7'-9") of the east screen well wall was determined to require repairs if more than 50% of rebars corrode beyond acceptable limits.

The intake tunnel ceiling slab at Elevation (-) l1'-o" between the MOV-9 and the screen well was determined to require repairs if more than 50% of rebars corrode beyond acceptable limits.

The north wall portion below Elevation (-) 14'-0" between the tsunami gate slot wall and the MOV-9 gate slot wall was determined to require repairs if more than 25% of rebars corrode beyond the acceptable limits.

The surveillance results indicate that the level of corrosion in the latter three areas is such that the design margins are not compromised. This conclusion is based on insignificant changes in the amount and size of rust spots and their pattern as well as other corrosion indications.

Based on the findings of the 1984 and 1986 investigations, the 1988 surveillance data did not provide corrosion indications which were significant enough to require repairs or further investigation except for the north wall crossover. The size and characteristics of the rust spots, the number of spots and their location were such that had similar observations been made in 1984 further investigation would not have been necessary and that portion of the structure would have been considered suitable to return to service. The observed rust spots were not concentrated, but they were randomly spaced and did not display a distinct pattern as in 1984. The diameter of the rust spots and the concrete discoloration did not change measurably from the 1986 observations. Only minor concrete spalling was observed with no indication of concrete delamination. Thus, the change in the condition of the intake structure is insignificant except for the north wall crossover area.

5.0 REPAIRS The repairs of the north wall crossover were performed underwater by divers in January 1989. The repairs consisted of two horizontal 7'-3" long plates (plate material is steel ASTM A-588 with minimum F =50 ksi) attached to the wall with monel anchor studX. The plates were placed at Elevations (-) 5'-0 1/2" and

(-) 9'-0 1/2". The 1-1/4" diameter holes for the anchor studs were core drilled and then roughened with a drill. Sikadur 36 by Sika Corporation was used for anchoring the 1" diameter anchor studs.

Page 14 6.0 CONCLUsIONS.

The intake structure was visually inspected and half pcedreads Itr isk concluetquired per surveillance c

ue t p concluded that the structure will aote the nextom its safety related functions until at least the next surveillance for the Cycle XI refueling outage because no significant changes in the condition of the structure were observed except for the north wall crossover which was repaired in January 1989.

The north wall crossover was suspected of undergoing the process of accelerated corrosidn based on the visual inspection and was repaired.

Visual observations of the intake structure reveal that the structure has numerous rust spots with concrete surface discoloration and exuding rust products.

However, except for the north wall crossover, there were no significnt changes in the structure's condition since it was inspected in 1986.

The half-cell readings were inconclusive and were not used for evaluation of the intake structure. No correlation between the readings and the raNe of corrosion was established. The half-cell readings will be evaluated for exclusion from the scope of future, surveillances.

The repairs which were performed in 1984 showed no sign of distress or deficiencies.

Page 15

7.0 REFERENCES

1.

Letter to D.M. Crutchfield (NRC) from K.P. Baskin, dated December 8, 1981; Subject Docket No. 50-206 SEP Topic 111-6 Seismic Design Consideration, and "Balance of Plant Structures Seismic Reevaluation Program"

2.

Letter to G.J. Stawniczy from P.J. Speidel (BPC),

dated June 11, 1986;

Subject:

Intake Structure Surveillance Report, and "Report of First Surveillance for SONGS Unit 1 Intake Structure"

3.

Letter to W.A. Paulson (NRC) from M.O. Medford, dated October 18, 1984;

Subject:

Intake Structure Degradation Repair. Structural Evaluation and Repair of SONGS Unit 1 Intake Structure, BPC, Revision 1, October 2, 1984

4.

Surveillance Guidelines for SONGS Unit 1 Intake Structure, BPC, January, 1986

5.

Letter to J.A. Zwolinski (NRC) from M.O. Medford, dated October 4, 1985;

Subject:

Intake Structure Surveillance Guidelines. Surveillance Guidelines for SONGS Unit 1 Intake Structure, BPC, October, 1985

6.

Letter to K.P. Baskin from T.M. Novak (NRC), dated July 11, 1986;

Subject:

Long-Term Service (LTS)

Seismic Reevaluation Program.

Enclosure:

Safety Evaluation Relating to the Long Term Service Seismic Reevaluation Program, Docket No. 50-206

7.

Intake Structure -

Diver Half Cell Potential Measurements and Surveillance Inspection, Maintenance Procedure S01-I-2.55, SCE

8.

Intake Structure Core Sample Drilling, Inspection and Chloride Content Testing, Maintenance Procedure S01-I-2.56, SCE

9.

Calculations CWIS-CC-01, -02, ISR-CC-01 with Supplement.

(II)

APPENDIX A

Page 2 of 33 APPENDIX A --

VISUAL OBSERVATION FIELD NOTES The following areas were selected during he underwater visual inspection process as points of interest on basis of visual signs of distress and are described below, in the video tapes, and on the drawings where they are identified by corresponding numbers.

The reference at the end of each item is to indicate where the item is shown on the video tape and drawings.

The areas are defined as follows:

1.

The transition from circular pipe to square box (transition section), just west of the tsunami &ate, has a large crack in the floor at the centerline varying in width from 6" to 2" which extends diagonally southeastward from the-interface with the pipe for about 7 ft, can be probed to about 2 1/2" depth with a pointed rod of about 3/16" diameter. There is a triangular piece of concrete missing from the apex of this crack with item 2 (below) that is about 8 inches in length.

No rust products are evident in this crack system and no concrete remains in the crack.

Based on conversations with the diver, this crack and item 2 are evidently cracks that have been present for a period of years and were seen in previous (diving) inspections.

(Ref. Tape No. 1 and Figure

8)

2.

In the transition section a second crack starting at the pipe interface at floor centerline at the point of start of item 1 extends about 4 feet diagonally north east and is about 14" wide can be probed about 1 1/2" in depth.

Has same characteristics as crack of item 1. (Ref. Tape No. 1 and Figure 8)

3.

In the transition section ceiling a crack, 1/8 " wide 2 feet in length and probing to about 1" in depth is located 5 feet west of the tsunami gate 4 feet south of the centerline.

There is no rust color or rust products associated with this crack.

(Ref. Tape No. 1 and Figure 9)

4.

In the floor of the tunnel immediately below the tsunami gate, there is a copper plate embedded.

Immediately west of the plate the concrete is spalled away to a maximum of 8" and depth of about 1/2".

The concrete is stained with black corrosion products and the plate is stained blue-green.

(Ref. Tape No. 1 and Figure 8)

5.

This item is the same as item 4 but occurs on the eastern boundary of the copper embedded plate and concrete floor.

(Ref. Tape No. 1 and Figure 8)

Page 3 of 33

6.

The copper embedded guide in the north tsunami gate slot is hanging loose in the slot supported at only a few anchors.

The edges of the embed are corroding.

The condition of the gate is much.the same as it appeared in previous inspections.

The retaining anchors which were added in the past to correct the loose hanging conditions have corroded away.

(Ref. Tape No. 1 and Figure 10)

7.

On the north wall up in the tsunami gate.cavity, there is a 5" by 2" area of spalled concrete which is 5" from the edge of the gate slot 6 feet above the tunnel ceiling.

(Ref.

Tape No..1 and Figure 10)

8.

In the tsunami gate cavity about 1 foot below the ledge that supported the gate operators, the walls have a 7" deep strip, around the perimeter, of unconsolidated concrete that appears to be a construction joint.

The strip has heavy rust stains on the concrete which appear to come from steel that is corroding above this area.

(Ref. Tape No. 1 and Figure 10)

9.

The ledge which forms the ceiling of the tsunami gate cavity has a large area of delaminated concrete that has broken away from the first layer of reinforcing steel exposing 9 bars that run east and west.

The bars are corroded through the entire diameter. The three inches of concrete cover over the bars has deteriorated and spalled off. Bars are about 1 ft apart.

A steel plate that may have been used as the underside of the forms for this ledge and apparently left in place is corroded away.

The severe corrosion and loss of concrete cover makes it reasonable to conclude that this deterioration has been occurring over the years but was not noted in the 1984 inspection because at that time the tsunami gate was in position and the structure was dewatered.

This condition left no access to the cavity for visual inspection.

(Ref. Tape No. 1 and Figures 9, 10)

10.

The south gate slot for the tsunami gate contains an imbedded copper liner which is hanging loose, with its edges corroding and the anchors added in the past to correct the loss of support have corroded.

In places, the plate is hanging about an inch away from the concrete.

(Ref. Tape No. 1 and Figure 11)

11.

The east side of the tsunami gate slot at the south wall there is an area of spalled concrete that extends from the floor to about 2 ft above the floor and is about 3 1/2" wide.

The concrete is stained with red rust color and contains soft black rust products.

(Ref. Tape No. 1 and Figure 11)

Page 4 of 33

12.

In the heat treat cross over area between MOV 9 and the tsunami gate in the east wall 5" above the ceiling of the tunnel there is a system of cracks that extend across the north south length of the wall.

The cracks are discolored by rust products with red and orange stains at the surface with black rust products evident below the surface of the cracks.

The concrete adjacent to the slot easily spalls to about 1/2" depth.

(Ref. Tape No. 1 and Figure 10)

13.

The south wall 5 ft east of east edge of MOV 11 there are 4 rust spots in a vertical line down the wall.

a) The first spot is 18" down from ceiling level, about 1 1/2" in diameter and protrudes 3/4" from the surface of orange rust color.

b) At 5 1/2 ft down from ceiling also 5' east of MOV 11 a rust spot of 1 1/2" diameter protrudes 1/2" from surface of orange rust color within a larger rust stain of 6" diameter.

c) At 5" above the floor and also 5' east of MOV 11 there is a third rust spot 3" diameter of dark reddish brown rust stain.

d) Also 5' above the floor but 6' east of MOV 11 there is a rust stain that is 6" long by 2" wide. Also see item 134.

(Ref. Tape No. 1, Tape No. 5 and Figure 11)

14.

North gate slot of MOV 9 at 4 ft below the ceiling west edge of the slot is spalled in an area of 14" x 3" and concrete is of normal color.

Also a rust spot 2" diameter of orange and reddish rust color is in the north west corner of the slot.

(Ref. Tape No. 2 and Figure 10)

Note:

MOV 9 was removed at this time for installation of gate stops allowing access to the slot.

15.

Also in the north gate slot of MOV 9 at 18" below the ceiling in the center of the slot there is an area of spalled concrete about 3/14" deep and 6" long by 3" high.

(Ref. Tape No. 2 and Figure 10)

16.

In the north gate slot of MOV 9 there is a 3" x 1/14" rust spot of dark red rust color 6" above the ceiling level.

(Ref. Tape No. 2 and Figure 10)

17.

In the north gate slot of MOV 9 there is a 2 ft long by 2" wide rust streak in the east corner just above ceiling level.

(Ref. Tape No. 2 and Figure 10)

Page 5 of 33

18.

In the ceiling of the tunnel at HOV 9'the gate opening there is a 2" diameter spall of normal color 1" deep at 6" above ceiling level 18" south of the north wall on the west face of the opening.

(Ref. Tape No. 2 and Figure 9)

19.

Also in the ceiling opening for MOV 9 at 3 1/2" south of the north wall there is a 2 1/2" diameter dark red and light orange rust colored spot about 6" above ceiling level on the west face of opening.

(Ref. Tape No. 2 and Figure 9)

20.

MOV 9 ceiling opening on the west face on the corner with the ceiling there is a 1" diameter dark red rust colored spot at 18" north of the south wall.

(Ref. Tape No. 2 and Figure 9)

21.

The MOV 9 ceiling opening east face has a corner with 1" of concrete spalled away at 12" south of the north wall.

(Ref.

Tape No. 2 and Figure 9)

22.

The MOV 9 ceiling opening east face at 2' south of north wall just above ceiling level there is a 5" long 2" wide dark and light red rust colored spot with some spalling of concrete.

(Ref. Tape No. 2 and Figure 9)

23.

MOV 9 ceiling opening east face about 5 ft south of north wall at 1 1/2 ft about ceiling level there is a 2" diameter rust spot of dark rust color protruding 1/14" from the surface of soft texture rust products.

(Ref. Tape No. 2 and Figure 9)

24.

MOV 9 ceiling opening east face at 7 ft south of north wall and 7" above ceiling level there is a 2" diameter rust spot and an S shaped spot about 2" long of spalled concrete with heavy rust stains in the spall.

(Ref. Tape No. 2 and Figure

9)

25.

MOV 9 ceiling opening east face at 4 ft north of the south wall at 7" above ceiling level there is a 3" diameter orange rust colored spot.

(Ref. Tape No. 2 and Figure 9)

26.

In the same area as item 25 there is a 3" diameter rust spot that protrudes 1/14" of soft textured 'orange rust products.

(Ref. Tape No. 2 and Figure 9)

27.

MOV 9 at 6" above ceiling level at the south slot in the east face there is a 1 1/2" diameter light orange rust spot with spalling concrete extending up the gate slot.

(Ref.

Tape No. 2 and Figure 9)

28.

MOV 9 at 6" above ceiling 6" north of south wall there is a spalled area 3" long by 1 1/2" wide with dark brown and black rust stains.

(Ref. Tape No. 2 and Figure 9)

Page 6 of 33

29.

MOV 9 south gate slot 4 ft above floor there is a 2 ft long crack in the silicon-bronze liner in the east corner of the slot.

(Ref. Tape No. 2 and Figure 11)

30.

MOV 9 south gate slot 4 ft from the floor level there is a 2 ft long 4" wide bright orange colored rust spot in the concrete at the corner of the slot.

(Ref. Tape No. 2 and Figure 11)

31. -NOV 9 south gate slot 12" above floor level there is a 12" long 1 1/2" wide orange rust colored spot in the east corner of the slot.

(Ref. Tape No. 2 and Figure 11)

32.

North wall of cross-over 2 ft east of the tsunami gate and 10 ft above the floor level there is a 12" long 1/2" wide rust spot with rust products deposited on the wall.

(Ref.

Tape No. 3 and Figure 10)

33.

North wall of cross-over 6" east of the tsunami gate about 10 ft above floor level there is a 6" long 4" wide oblong rust spot of dark reddish rust color and a spot that extends from there to the ceiling. This is evidently the boundary between the first pour of concrete at the block out for the gate slot and the second pour which formed the gate slot.

(Ref. Tape No. 3 and Figure 10)

34.

South wall of cross-over 1 ft east of the tsunami gate and 2 ft above floor level there is a light orange and dark reddish rust colored spot that appears to be spalling of concrete that can be probed, at separation, to 1/2" depth with a visible separation of 3/4" that extends at a shallow angle into the depth of the wall.

The crack is 7" long.

(Ref. Tape No. 3 and Figure 11)

35.

South wall of cross-over 5 ft east of tsunami gate there is spalling of concrete plus three rust spots of 3" diameter in an area of 3' diameter.

The spots are of dark and light rust coloration.

The area is about 3 ft above floor level.

(Ref. Tape No. 3 and Figure 11)

36.

South wall of cross-over 12 ft west of NOV 9 and 4 ft above floor level a rust spot of 3" diameter of dark red rust color also has a 2" diameter black spot within the larger spot of black rust coloration with spalling of concrete in the black spot.

(Ref. Tape No. 3 and Figure 11)

37.

South wall of cross-over 2 1/2 ft west of MOV 9 at 1 ft above floor level there is a T shaped rust spot that is 6" long by 3" wide of brown and reddish rust color.

(Ref. Tape No. 3 and Figure 11)

Page 7 of 33

38.

South wall of cross-over 3 ft west of MOV 9 and 2" above floor level there is a 2" wide 5" long dark rust stain that can be easily gouged to 1/14" deep of dark rust products.

Spalling of concrete is evident within this spot.

(Ref.

Tape No. 3 and Figure 11)

39.

South wall 2" west of MOV 9 and 2 1/2 feet above floor level there is a protruding rust spot of light red rust color with the center protruding 1/8" beyond the concrete surface of dark rust color with black rust products beneath surface crust.

(Ref. Tape No. 3 and Figure 11)

40.

South wall is covered with barnacles which protrude individually.about 1" from the surface. There is a 1/8" thick growth of algae which covers approximately 60S of the surface area.

This is somewhat typical of the north wall and the rest of the interior of the intake structure.

(Ref.

Tape 3 and Figure 11)

41.

Core Drill No. 15 and repaired area --

The color and appearance of these items give no sign of interaction or activity between the old concrete and reinforcing steel and the repaired area.

(Ref. Tape No. 3 and Figure 10)

42.

North wall 6" east of MOV 9 there is at 18" above floor level a 1 ft diameter rust spot with a 2" diameter center that protrudes 1/2" from the surface.

There is a crack that can be probed to 1/2" depth that runs from this spot to MOV 9 gate slot.

There is also a spalling crack that runs from the floor to the ceiling through this spot.

The crack is probably the edge of a blockout that was later filled when the gate slot was formed.

(Ref. Tape No. 3 and Figure 10)

43.

North wall 15 ft east of MOV 9 there appears to be a spalling crack from floor to ceiling that can be probed to 1/2" depth.

There is no discoloration associated with this crack.

The. crack appears to be either a construction joint or a form joint with only the edges of the joint spalling.

(Ref. Tape No. 3 and Figure 10)

44.

South wall 1" west of MOV 11 opening 5 ft above floor level there is a 5 ft long 1/8 " wide crack that can be probed 1/4" with.no discoloration.

Also 5" east of MOV 9 at 1/4" above floor level there is a 1" long rust spot.

(Ref. Tape No. 3 and Figure 11)

45.

MOV 11 --

The gate itself has a crack pattern that exudes white material to highlight the cracks. The cracks are much as appeared in 1984 and are not considered to be significant.

(Ref. Tape No. 3 and Figure 11)

Page 8 of 33

46.

North wall in tunnel approaching screen well --

There is a 1" diameter orange rust colored spot that protrudes rust about 1/4" beyond wall surface 6" above the floor and even with east nose of flow vane.

(Ref. Tape No. 3 and Figure

10)

47.

North wall 6" above floor level 1 ft east of east nose of flow vane there is a 1" diameter rust spot of dark red rust color.

(Ref. Tape No. 3 and Figure 10)

48.

North flow vane --

The north side of the north flow vane has no significant spots or cracks to report.

The west nose of the flow vane has a crack system (as seen in 1984) that runs the full height df the vane that varies in width from 1/8" to 2" and about 1/4" in depth by probing.

Intermittent dark rust discolors the crack system.

The south side of the north flow vane has random minor pitting and spalling.

(Ref. Tape No. 3 and Figure 8)

49.

On the north flow vane --

east nose, a crack pattern exists which runs the full height and varies to a maximum of 1" in width and allows probes to 1" depth along with intermittent rust stains and protruding rust along the cracks-(appears much as it did in 1984).

(Ref. Tape No. 3 and Figure 8)

50.

Repair of chipped area R and R-1.

There was no sign of interaction or distress between repaired area and old concrete.

(Ref. Tape No. 3 and Figure 10)

51.

North wall of north screen well --

There is a 6" to 8" wide reddish rust spot 10" east of gate slot that extends from 1 ft above floor level to 11 ft above floor level where it ends abruptly -

10 ft long rust spot.

(Ref. Tape No. 3 and Figure 10)

52.

North wall repaired gate slot.

The new concrete looks good but old concrete east of the bar screen slot is heavily rust colored.

There appears to be no adverse reaction between old and new concrete. The rust stains on this wall appear to be migrating from above and this as well as other spots on the north wall may be forming from the migrating rust.

The ladder anchors above are contributing to much of the rust stains.

(Ref. Tape No. 3 and Figure 10)

53.

All strap plates in north screen well appear in good condition none of the nuts appear to have loosened.

(Ref.

Tape No. 3 and Figure 10)

Page 9 of 33

54.

North screen.well south wall (intermediate wall) -- There is a 2" diameter orange rust colored spot which protrudes rust 1/4I" from the surface 6 ft above floor level 8"1 west Of stop gate slot.

The discoloration easily breaks away and is of soft texture-.

(Ref. Tape No. 3 and Figure 13)

55.

South wall of north screen well --

There is a 2" wide 4" long rust spot protruding 1/2" from surface of reddish rust color which is black rust products beneath surface that is located 10" west of stop gate slot 10 ft above floor level.

The rust products are easily broken away to about 1/4" depth.

(Ref. Tape No. 3 and Figure 13)

56.

South wall of north screen well --

An expansion anchor bolt for a core drill remains in place in a rust spot that is 3 ft below the tunnel ceiling 1 ft west of the stop gate slot.

(Ref. Tape No. 3 and Figure 13)

57.

South wall of north screen well --

a rust spot in the gate slot 5 ft below the tunnel ceiling.

Spot is 1" diameter of orange and black rust color.

Rust is easily penetrated to 1/4" depth.

(Ref. Tape No. 3 and Figure 13)

58.

South wall of north screen well has a rust spot in the stop gate slot of 3" diameter, 8 ft above floor level that protrudes 1/2" of rust color.

(Ref. Tape No. 3 and Figure

13)

59.

South wall of north screen well -- The gate slot and the surface just west of slot has numerous intermittent protruding rust spots and cracks up and down the full height of the slot.

Rust protrudes up to 1" beyond surface of concrete.

(Ref. Tape No. 3 and Figure 13)

60.

South wall of north screen well --

The strap plates look good with no rusting but black coating is peeling away in places.

(Ref. Tape No. 3 and Figure 13)

61.

North wall of north pump bay just east of strap plate No. 4 and 6 ft below the ceiling there is a rust spot of 6" diameter of light rust color which protrudes 1" beyond the concrete surface. Strap plates No. 1 through 4 look good.

(Ref. Tape No. 3 and Figure 10)

62.

North wall of north pump bay just east of strap plate No. 5 there is a 6" diameter rust spot 6 ft below the ceiling with light rust coloration and rust protruding 1 ft beyond concrete surface. Strap No. 5 looks good.

(Ref. Tape No. 3 and Figure 10) 63A. North wall of north pump bay 1" east of strap No. 6 there is a 2n diameter reddish rust colored spot of rust protruding 1" beyond the concrete surface of soft black rust texture.

(Ref. Tape No. 3 and Figure 10)

Page 10 of 33 63B. Straps No. 6 through 13 look good.

Strap No. 14 also looks good.

Along the east wall of north pump bay straps No. 15 through 18 look good.

(Ref. Tape No. 3 and Figures 10 and 63C. The concrete surface in the ceiling beam west of the north circulating water pump looks good with no rust or discoloration evident, however visibility here is not good.

(Ref. Tape No. 3, Figure 9) 63D.

Strap No.

23 in the north intermediate wall looks good but there is a rust spot of 2" diameter 2 ft west of strap plate No.

23 of orange rust color 1 ft below the ceiling that protrudes rusts 1/2" beyond surface., (Ref. Tape No. 3 and Figure 13) 63E. Strap No. 24 looks good.

(Ref. Tape No. 3 and Figure 13) 63F. Ceiling strap No. 31 looks good.

A general inspection of the north pump bay, ceiling indicates a few random rust spots, however, this inspection was limited by poor visibility.

(Ref. Tape No. 3 and Figure 9)

64.

North wall of north screen well --

The bar screen slot has intermittent heavy rust spots up and down its height.

(Ref.

Tape No. 4 and Figure 10)

65.

North wall of north screen well 1 1/2 ft east of bar screen slot that extends from 2 1/2 ft above floor level to 12 ft above floor level varies in width from 4 " to 12" and of light rust color.

(Ref. Tape No. 4 and Figure 10)

66.

North wall of north screen well light colored rust spot 4" to 12" wide 2 1/2 ft long broken and then 10' long starts 1 1/2 ft above floor level tapers towards east upward located about 3 1/2 ft east of bar screen slot.

Spot tapers into strap plate.

Strap plate is in good condition.

(Ref. Tape No. 4 and Figure 10)

67.

North wall of north screen well 5 ft east of bar screen slot there is a 1 1/2" diameter rust spot 4 ft above floor level.

(Ref. Tape No. 4 and Figure 10)

68.

North wall of north screen well rust stain starts at the bar screen slot about 3 ft above floor level goes upward west of slot extends to 2 ft below water surface and is about 2" wide.

(Ref. Tape No. 4 and Figure 10)

69.

North wall of north screen well --

There is a protruding rust spot 3 ft west of bar screen slot which protrudes about 1/2" of rust.

(Ref.

Tape No.

4 and Figure 10)

Page 11 of 33

70.

North wall of north screen well at 11 ft above floor level and 5 ft west of traveling screen there is a 5" long by e wide strip of rust discoloration on the concrete surface that appears to run under strap plate.

Strap plate is not rusted or stained.

(Ref. Tape No. 4 and Figure 10)

71.

In the west corner of the north wall of north screen well 6 ft above tunnel ceiling level there is a 1/4" protrusion of rust product of light and dark rust color that is 1" high by 1" wide.

The bar screen slot has intermittent rust spots in it up and down its full height.

(Ref. Tape No. 4 and Figure

10)

Note:

Items 71 through 83 are abovp the new concrete of the repaired area.

72.

The stop gate slot in the north wall of the north screen well has a 1" x 3" rust spot of light and dark rust color with rust protruding 1/2" at 4 ft above the tunnel ceiling level.

(Ref. Tape No. 4 and Figure 10)

73.

The stop gate slot in north wall of north screen well has rust spots and spalling with rust protruding 1/2".

Spall is 1/4" deep in a 3 1/2" diameter.

Rust spot of 3 ft length of light and dark rust color varies in width from 1/2" to 3" and begins at 4 ft above tunnel ceiling level and extends upward for its 3 ft length.

(Ref. Tape No. 4 and Figure 10)

74.

Strap No. 68 in the north wall is rust stained for the top 10" of length.

This stain, however, is coming from rust spot on concrete above the strap plate.

Concrete above is stained in a 6" strip that runs upward to 3 ft above the strap plate.

There are protruding rust spots within the stained strip that protrude from 1/2" to 1" beyond concrete surface.

Strap No. 68 is in good condition.

(Ref. Tape No.

4 and Figure 10)

Note:

The rust spots and rust stains for items 74 and 75 are evidently migrating from above where anchors for the ladder and the ladder itself is corroding.

75.

North wall of north screen well at 1 ft east of stop gate slot there is a dark and light rust colored strip that is about 6 ft long and 6" to 8" in width. Within this strip there is a protrusion of rust products that is 8" high by 2" wide with 1/2" of protrusion.

The rust strip begins at 3 ft below top of strap plate and extends to 3 ft above top of strap plate.

(Ref. Tape No. 4 and Figure 10)

76.

North wall north screen well at 3 ft east of bar screen slot and 6 ft above tunnel ceiling there ar6 two protruding rust spots each one ft long with protrusions of 1/4".

(Ref. Tape No. 4 and Figure 10)

Page 12 of 33

77.

North wall of north screen well at 3 ft west of traveling screen and 5 ft above tunnel ceiling there is a 1" x 1" light and dark rust colored spot that protrudes 1/8".

(Ref.

Tape No. 4 and Figure 10)

78.

North wall of north screen well at 1 ft east of bar screen slot there are three light and dark rust colored spots with rust protruding 1/4" to 1/2".

One spot is 6 ft above

. ceiling level of 3" width by 4" length.

Another spot is 6 1/2 ft above ceiling level is 6 to 8" wide and 2 ft long.

A third spot is 12 ft above ceiling level of 6" by 1" size.

(Ref. Tape No. 4 and Figure 10)

79.

North wall north screen well at thebar screen slot 12 ft a -.

above tunnel ceiling level there is a 2 ft by 3 ft rust spot with protruded areas inside the rust spot.

One protrusion of 1/4" is 6" wide by 14" high and another protrudes 1/8" is 2" x 1".

Light and dark rust coloration.

(Ref. Tape No. 4 and Figure 10)

80.

North wall of north screen well at 6" east of stop gate slot and 12 ft above tunnel ceiling level there is a light and dark rust colored spot that is 1 ft long and 3" wide with areas of rust protruding 1/14" from the surface of the concrete.

(Ref. Tape No. 4 and Figure 10)

81.

North wall of north screen well.

Rust spot 1 ft long and 6" wide narrows to 1" wide where 1/2" diameter of rust products protrudes 1/2" located 1 ft west of stop gate slot 12 ft above ceiling level.

Rust also surrounds pipe support bracket in this location.

(Ref. Tape No. 4 and Figure 10)

82.

North wall of north screen well has a 8" x 14" light and dark rust colored area of spalled and pitted concrete surface behind plastic pipe 13 ft above tunnel ceiling level.

(Ref.

Tape No. 4 and Figure 10)

83.

North wall of north screen well 6" west of stop gate slot 14' above tunnel ceiling level a rust spot 6" long by 1 to 3" wide protrudes 1/4" of rust.

(Ref.-Tape No. 4 and Figure

10)

84.

Ceiling of tunnel in approach to screen well contains several rust spots in an area 18" x 8" of light and dark rust coloration that protrudes 1/4" to 4" from the concrete surface. This area is located 3 ft south of the north wall and 4 ft west of east edge of the ceiling.

(Ref. Tape No. 4 and Figure 9)

85.

Ceiling of tunnel in approach to screen well a rust protrusion of 1/2" x 1/2" area protrudes 1/2" from concrete surface located 15" south from north wall 4 ft west of east edge of ceiling.

(Ref. Tape No. 4 and Figure 9)

Page 13 of 33

86.

Ceiling of tunnel in approach to screen well contains a n" x 2" light and dark rust colored spot that protrudes 1 1/2" from the surface located 4 ft south of north wall and 5 ft west of the east edge of the ceiling.

(Ref. Tape No. 4 and Figure 9)

87.

South wall of south screen well at 6" east of the west corner and 3 ft above the tunnel ceiling there is an oblong 6" by 8" protruding rust spot that protrudes light and dark rust colored corrosion 4" beyond concrete surface.

Just

-next to this spot is a 1/2" x 1/2" rust spot that protrudes 1/2" from the concrete surface.

(Ref. Tape No. 4 and Figure

88.

The stop gate slot in the south walli exudes rust products, contains cracks also exuding rust, and shows signs of concrete spalling intermittently all up and down its height.

(Ref. Tape No. 4 and Figure 11)

89.

In the south wall of the south screen well there are an additional 12 rust spots of up to 2" diameter each located randomly in the wall from floor level to about 6 ft above the floor level.

The steel strap plates are in good condition in this wall.

The bar screen slot has exuding rust spots throughout its height.

(Ref. Tape No. 4 and Figure 11)

90.

The north wall (intermediate wall) of the south screen well in the area between the stop gate slot and the traveling screen contains no significant rust discoloration or signs of distress.

Just west of the stop gate slot at 2 1/2 ft above floor level there is a pipe support bracket with completely corroded anchor bolts and a rust spot protruding from 1" to 3" beyond the concrete surface.

The concrete surface behind the vertical pipe run has excessive corrosion products discoloring the concrete from floor to ceiling.

Just east of the nose of the intermediate wall there is a 6 ft long vertical crack, discolored with rust products, extending from 6 ft above floor level to 12 ft above floor level.

This crack appears to be the interface between repairs done in 1984 and the original concrete. The steel strap plates in the wall are in good condition.

Brackets for the vertical run of pipe in this area are corroded away at 15 ft above floor level.

(Ref. Tape No. 4 and Figure 12)

91.

The nose of the intermediate wall contains several rust spots.

There is a 3/4" diameter rust spot 4 ft above floor level.

There are 3 rust spots within 6" above floor level with a 1 ft long vertical crack, starting at these spots, protruding 1/2" of rust products of light and dark rust color which easily breaks away.

All these spots and cracks are in the nose of the intermediate wall.

(Ref. Tape No. 4 and Figure 12)

Page 14 of 33

92.

South wall (intermediate wall) of the north screen well at 1 ft west of the gate slot a vertical crack starts at floor level, runs*8 ft up the wall, has a 18" break then begins again and continues to 6 ft above the tunnel ceiling level.

Width of the crack allows a knife blade to be inserted.

Heavy rust products protrude from 1/8 " to 3" from the crack.

(Ref. Tape No. 4 and Figure 13)

93.

South wall of the north screen well there is a protruding rust stain 2 1/2" x 2" which protrudes 1/2" of light and dark colored rust located 1 1/2" ft east of the gate slot at the tunnel ceiling level.

At 3 ft above ceiling level just east of the gate slot there are 2 more rust spots that are 10" long by 5" wide of dark and light rust coloration and protrudes rust products 1/2" beyond'the concrete surface.

(Ref. Tape No. 4 and Figure 13)

At 8 ft above ceiling level and just east of the gate slot there is a 16" x 7" rust colored area that protrudes rust 1/2" from the concrete surface.

(Ref. Tape No. 4 and Figure

13)

There are protruding rust spots that protrude 1/4 to 3/4" intermittently up and down the length of the gate slot.

(Ref. Tape No. 4 and Figure 13)

Brackets from the supports for the vertical plastic pipe are missing (corroded away).

(Ref. Tape No. 4 and Figure 13)

The bar screen slot has intermittent protruding rust spots up and down the full height.

(Ref. Tape No. 4 and Figure

13)

94.

South wall of the north screen well at 6 ft east of bar screen slot and 8" above floor level there is a 2 1/2" x 2" spot of protruding rust, protrudes 1/2" from the concrete surface.

(Ref. Tape No. 4 and Figure 13) 2 1/2 ft above the floor at this location there is a 8" x 4" dark rust spot that protrudes rust 1" from the concrete surface. A third spot at 3 ft above floor level of 3" x 2" also protrudes rust.

(Ref. Tape No. 4 and Figure 13)

.95.

Ceiling of tunnel east of MOV 9 in area of flow vanes at 8" west of the east edges these is a 4" x 6" rust spot that protrudes 1" of rust of light and dark rust color located at 6 ft south of the centerline.

(Ref. Tape No. 4 and Figure

9)

96.

Ceiling of tunnel at 6 ft west of the east edge of ceiling and 4 ft south of the north wall there is a 6" x 3" light and dark rust colored spot that protrudes rust 2".

(Ref.

Tape No. 4 and Figure 9)

Page 15 of 33

97.

The cross-over area between the tsunami gate and MOV 9 the ceiling was scanned with nothing of significance found.

Ceiling looks good.

(Ref. Tape No. 4 and Figure 9)

98.

The cross-over area north wall -

visibility was poor.

One rust area of 3" x 2" was found but overall the wall appears in good condition.

(Ref. Tape No. 4 and Figure 10)

99.

South pump bay south wall at 8" east of strap plate 83 at 18" above floor level there is a 4" diameter light and dark rust colored spot that protrudes 1/2" from the concrete surface.

(Ref. Tape No. 5 and Figure 11) 100. South pump bay south wall at 8" east, of strap plate 83 and 7 ft above floor level there is a 1/2" diameter rust spot.

(Ref. Tape No. 5 and Figure 11) 101. South wall of south screen well at 8" east of strap plate 83 and 24 ft above floor level there is a 2" diameter rust spot.

Strap plate 83 is in good condition.

(Ref. Tape No.

5 and Figure 11) 102. South wall of south pump bay at 14" west of strap plate 59 and 5 ft below ceiling level there is a 1/2" diameter black and red rust spot.

(Ref. Tape No. 5 and Figure 11) 103. South wall of south pump bay at 1/2" east of strap plate 59 there is a 3" by 1" orange, yellow and black rust spot that protrudes 1/4" located 7 ft below ceiling level.

(Ref. Tape No. 5 and Figure 11) 104. South wall of south pump bay between strap plates 58 and 59 there is at 10 ft below the ceiling a 2" diameter rust spot that protrudes 1/2" with a 1/8" diameter hole through the center which penetrates into the concrete.

Strap 59 is in good condition.

(Ref. Tape No. 5 and Figure 11) 105. South wall the south pump stop gate slot has intermittent rust spots up and down its height. The slots are just east of the traveling screens and were abandoned for use as stop gate slots.

(Ref. Tape No. 5 and Figure 11) 106. South wall in south pump bay at 18" below the top edge of strap 58 there is a 12" diameter area containing 4 rust spots of 2" diameter each which protrude from 1/2 to 1" of orange red rust.

Strap plate 58 is in good condition.

(Ref. Tape No. 5 and Figure 11) 107. South wall of south pump bay at 5 ft above floor level a rust spot extends from beneath strap plate 57 to 2" west of the strap and is about 2" wide of red rust color that can be penetrated to a black interior of 1/8" depth into concrete.

Strap plate 57 is in good condition.

(Ref. Tape No. 5 and Figure 11)

Page 16 of 33 108. South wall of south pump bay at 6" east of strap 57 at 5 ft above floor level there is a 6" dark red rust spot with a 3 diameter hole into the concrete and a 1/2" diameter light orange spot with a 1/4" diameter hole that penetrates 1/41 into concrete.

Straps No. 55 and 56 are in good condition with no discolored concrete adjacent to strap 56.

(Ref.

Tape No. 5 and Figure 11) 109. In the south wall at 3" below the ceiling and 2" east of strap 55 there is a 1" diameter bright orange rust spot that protrudes 1/4" of yellow and black rust products about 1/8" deep.

(Ref. Tape No. 5 and Figure 11) 110. In the south wall at 5 ft above floor level and 6" east Of strap 55 there is a bright orange and yellow rust spot of 6" 0 which protrudes, in spots, from 1/4" to 1/2".- (Ref.

Tape No. 5 and Figure 11) 111. In the south wall at 5 ft from floor level and 6" west of strap 55 there is an 18" long and 4" high strip of yellow and red rust color with spots within this strip of 2" diameter and 6" diameter rust protruding 1/8" from surface.

(Ref. Tape No. 5 and Figure 11) 112. In the south wall of the south pump bay at 5 ft above floor level and 6" west of strap No. 54 there is a 6" diameter bright red rust spot.

(Ref. Tape No. 5 and Figure 11) 113. In the south wall of the south pump bay 8" east of strap No.

54 and 5 ft above floor level there is a 5" by 2" wide strip of yellow and bright orange rust that protrudes 1" from the concrete surface.

(Ref. Tape No. 5 and Figure 11) 114. Running from under strap No. 54 there is a 4" diameter protruding rust spot at 15 ft above floor level with a'4" protrusion of bright orange and red rust.

Strap 54, however, is in good condition.

(Ref. Tape No. 5 and Figure 115. Also 20" east of strap No. 54 at 2 ft below ceiling level there is a 2" orange rust spot that protrudes 1/2" from the surface.

(Ref. Tape No. 5 and Figure 11) 116. On the south wall of the south pump bay at 5 ft above floor level and 3" east of strap No. 53 there is a 4" diameter bright red and orange rust spot that protrudes 4".

There is a reddish rust stain on the anode at this location. Straps No. 52 and 53 are in good condition.

(Ref. Tape No. 5 and Figure 11) 117. South wall of south pump bay at 3" west of strap No. 51 and 12" below ceiling level a 1" diameter rust spot protrudes 1/4" of bright red rust.

Strap No. 51 is in good condition.

(Ref. Tape No. 5 and Figure 11)

Page 17 of 33 118.

South wall of south pump bay at 18" east of strap No.

50 and 12 ft above floor level there is a 2" diameter rust spot that protrudes 1/8" from the surface.

Straps No.

45 throu 50 are in good condition.

(Ref.

Tape No.

5 and Figure 11) 119. East wall of south pump bay 18" south of strap 45 and 18" below the ceiling a 1/2" diameter rust spot protrudes 1/4" of bright orange red rust. Straps No. 42 through 45 are in good condition. Visibility too poor to inspect concealed beam in ceiling east of south circulating water pump.

(Ref.

Tape No. 5 and Figure 12)

And in the north wall of the south pump bay straps No. 35 through 38 and strap No. 66 are in good condition.

(Ref.

Tape No. 5 and Figure 12) 120. In the north wall of the south pump bay at 18" west of strap No. 35 and 5 ft above floor level there are 2 rust spots, a 6" diameter and a 3" diameter that protrude 1/2" to 1" of bright red and orange rust.

(Ref. Tape No. 5 and Figure 12) 121. In the north-wall of south pump bay 18" east of strap No.

35 and 15 ft above floor level in an area about 2 ft high there are 5 rust spots of bright orange red rust color of 3" to 4" diameter that protrude 1" to 1 1/2" of rust from the surface.

(Ref. Tape No. 5 and Figure 12) 122. North wall of south pump bay 4" east of strap No. 34 and 5 ft above floor level there is a 1 1/2" diameter bright red orange rust spot that protrudes 1/2" from the concrete surface.

(Ref. Tape No. 5 and Figure 12) 123. North pump stop gate slot for the south pump bay has intermittent rust spots that protrude up to 3" up and down the height of the slot. The slot is immediately east of the traveling screen and have been abandoned for use as pump stop gate slots.

(Ref. Tape No. 5 and Figure 12) 124. North wall of south pump bay 6" east of strap No. 82 and 10 ft above floor level there is an 8".long by 4" wide rust spot that protrudes 2" of bright orange red rust.

(Ref.

Tape No. 5 and Figure 12) 125. At 6" east of strap No. 82 at 4 ft above ceiling level there is a 4" diameter bright orange rust spot that protrudes 1/4" from the concrete surface. Strap No. 82 is in good condition.

(Ref. Tape No. 5 and Figure 12) 126. At 8" east of strap No. 82 and 9 ft above ceiling level there is a 1 1/2" diameter bright orange rust spot that protrudes 1/4" from the surface.

(Ref. Tape No. 5 and Figure 12)

Page 18 of 33 In accordance with section 6.2 of Maintenance Procedure S01-I-2.55, the following items are recorded:

127. Paragraph 6.2.4.4 --

Video indicates panning of stop gate slot in north screen well.

Rust previously noted on strap plate No. 68 is from rust stain on concrete above. Strap plate and coating is intact and in good condition.

(Ref.

Tape No. 6 and Figure 10) 128. Paragraph 6.2.4.3 --

Concealed beam in the north wall of the north screen well is shown in the video tape.

(Ref. Tape No. 6 and Figure 10) 129. Paragraph 6.2.4.2 --

Repaired area in the north wall of north screen well.

Area around the'repair appears rust colored and stained with protruding rust.

(Ref. Tape No. 6 and Figure 10) 130. Video tape of top portion of strap plate No. 68.

(Ref. Tape No. 6 and Figure 10) 131. Ceiling of tunnel approaching screen well.

Cluster of exuding rust spots.

(Ref. Tape No. 6 and Figure 9) 132. Paragraph 6.2.4.1 --

Ceiling of tunnel at approach to the intermediate wall of screen well.

(Ref. Tape No. 6 and Figure 9) 133. Paragraph 6.2.1 --

Crossover north wall between the tsunami gate and MOV 9. (Ref. Tape No. 6 and Figure 10) 134. (Also see item #13) South wall 4 ft east of MOV 11 shows four rust spots:

a) At 18" below tunnel ceiling.

b) A 1 1/2" diameter orange rust spot protruding 1/4" in a 6" diameter rust stain at 4 ft below ceiling level.

c) A 3" diameter dark reddish rust spot at 5 " above floor level.

d) A 6" long 2" wide rust spot that is 6 ft east of MOV 11 and 3" above floor level.

(Ref. Tape No. 6 and Figure 11) liIe

Page 19 of 33 135. Paragraphs 6.2.2 and 6.2.4.5 --

Concealed beam in ceiling of north pump bay indicating the following:

o A 1/2" diameter hole in concrete that is rust stained at 3 ft south of north wall.

o A 1/2" diameter rust stained hole in the concrete at 4 ft south of the north wall and a 1/4" diameter hole.

o Rust spot 2 1/2" diameter east of strap No. 33 2 1/2" ft north of the south wall and another rust spot just east of this spot.

o Rust spots (2) of 1" diameter protruding 1/4" of dark rust 6n north of south wall.

(Ref. Tape No. 6, Figure 9 and Items 63C and 63F) 136. Paragraph 6.2.4.3 --

North wall of north pump bay area between strap plates No. 8 and 9. At 5 ft below ceiling:

o 3" diameter dark reddish rust spot that protrudes 1/2" from the surface.

o 1" diameter rust spot.

o 2 protruding rust spots of 3" diameter that protrudes 1 1/2" of rust from the surface.

o Large rust stain of 18" by 9" of reddish orange rust color with protrusions of rust of 1" from the concrete surface.

(Ref. Tape No. 6, Figure 10 and Items 63A and 63B) 137. Paragraph 6.2.4.3 --

Pump stop gate slot for the north pump bay scanning from bottom to top.

(Ref. Tape No. 6 and Figure 10)

The following observations were made while the upper portion of the south screen well was dewatered:

138. On the north wall of the south screen well at 1 ft above the top of the strap plates in elevation and 4 ft east of the stop gate slot there is a 2" diameter rust spot which is exuding rust products to the surface of the concrete.

139. North wall of south screen well at 6 ft east of the stop gate slot and 10 ft above the top of the strap plates there is a 3" diameter rust stain on the concrete surface.

140. North wall of the south screen well there is a 1 1/2" diameter rust stain on the concrete located at 2 ft west of the traveling screen at 10 1/2 ft above the top of strap plate level.

Page 20 of 33 141.

North wall of the south screen well at 5 ft east of the stop gate slot and 8 ft below the level of the top of strap plates there is an exuding rust spot 4" long by 2" wide which protrudes 1" of rust products from the surface of the concrete.

Page 21 of 33 VISUAL OBSERVATION FIELD NOTES TAKEN DURING SECONDS SURVEILLANCE 12/20/88 NORTH WALL 142.

Crack at construction joint, extending across the vail at ceiling level (El. -14) from east wall to west wall in the north wall of the crossover section. (Visual only).

Has numerous rust spots above and below the joint with hollow sounding across the joint. Joint is generally covered with rust stains.

143.

Crack that extends diagonally down 4 ft. from the construction joint in the north wall at elevation-14 then runs horizontal for 2 feet and then diagonally upward to rejoin the construction joint at the east wall of elevation-14. Crack can be penetrated to 3/16 inch depth.

144.

Crack, 2 ft. long horizontal at center of wall 6 ft. above ceiling of tunnel below pitting and rust spots of dark orange and red. Hollow sounding from 6 inches to 15 inches wide along the crack.

145.

Rust spot, 2 inches dia. of orange and red rust 5 ft. above ceiling level at center of wall rust exuding holes around this area, hole dia.

1/2 inch. In the north wall of crossover area.

146.

Hollow sounding area, light orange stained 6 ft. west of east wall 5 ft. above ceiling of tunnel below, area of 4' diameter in the north wall of the crossover section.

147.

Area of dark orange rust exuding holes, hollow sounding, in north wall of upper crossover area located 4 ft. west of the east wall and 3 ft.

below the uppermost ceiling.

148.

Discolored hollow sounding area 2 ft. vertical height by 5 ft.

horizontal length, heavily orange rust discolored starts at the west wall of the uppermost north wall of the crossover area and extends 5 feet to the east centered 5' above construction joint at tunnel roof.

149.

Spalled concrete from north gate slot of gate #9 at 9 ft. above the floor vest side of slot. Spall is 2 by 3' in size and approximately 1/8 inch deep. Seen also in 1986.

150.

Rust spot in lower north wall of crossover area 3 ft. below the tunnel ceiling and 6 ft. west of gate #9.

151.

Vertical crack and spall area 6 wide by 10 high located 8 ft east of tsunami gate and 3 ft. above the floor of the north wall of the crossover area. Area is rust stained and has soft concrete surface.

A small area in the center of spot, about 6 inch diameter sounds hollow.

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Page 22 of 33 Rust spot, 8 ft. east of Tsunami gate runs 3 ft. vertically and 1-1/2 ft. wide starts three ft. above the floor on the north wall of the crossover area.

Sounds hollow at center area of 6 inch diameter.

152.

Soft spotof concrete to depth of 3/4 inch with no discoloration of 6 inch diameter located 9 ft. east of tsunami gate 7 ft. above the floor on the north wall in the crossover area.

153.

Crack runs diagonally for 3 ft. length located 6 inches below the tunnel ceiling and 4 inches west of gate 9 slot, in the north wall of crossover section. Sounds hollow along the crack.

154.

Rust spot of 1-1/2" diameter located at the tunnel ceiling 3 ft east of west wall in the north wall of the crossover area.

155.

Rust spot of 1-1/2 inch diameter red surface black rust at-depth located in the north wall of crossover area 3 inches above tunnel roof and 3-1/2 ft. east of west wall.

NORTH WALL OF NORTH SCREEN WELL 156.

Rust spot corresponds to item 71 of previous surveillance, 1/2 diameter black rust.

157.

Rust spot, 1-1/2 inch diameter of dark red with orange perimeter protrudes 1/2 inch of rust from wall surface located on the north wall of north screen well 11 inches vest of west gate slot 8 ft. above the floor.

Previous No. 81.

158.

Rust spot, 5 inches long and 1-1/2 inches wide of dark orange rust with small area of hollow sound located on the north wall of north screen well 1-1/2 ft. east of west gate slot 3 ft. above top of steel plate. See No. 75 of previous surveillance.

159.

Rust spot, 2 inch diameter; also a strip 2 inches wide and 8 inches vertical length of dark red rust with penetration of 1 inch into concrete located in the north wall of the north screen well 4-1/2 ft.

above the top of steel plate and 6 inches east of west gate slot.

160.

Rust spot of 2 inch diameter 6 ft. above steel plate. See previous

1. 79.

161.

Rust spot in north wall of north screen well located 8 ft. above steel plate and 4 inches east of west gate slot size of 1-1/2 inch diameter protruding 5/8 inch out from 4urface of bright orange rust. See No.

80 of previous survey.

162.

Red spot 1 inch diameter of red rust on the north wall of north screen well 10 ft. above top of steel plate and 5 inches east of west gate slot.

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Page 23 of 33 Rust spot, 2" diameter heavy orange rust surface stain located in the north vail of north screen veil 7 ft. above the floor and 1 ft. east of the traveling bar screen. See previous No. 65.

164.

Soft concrete surface, 3 ft. diameter located on north vall of north screen well starting 3 ft. above the floor extending to 6 ft. above the floor and 1 ft. east of the traveling bar screen. Spot is rust stained on surface but clear within and solid.

165.

Rust spot located 7 ft. above floor between strap plates 70 and 71.

166.

Rust stains over wide area with 50 diameter hollow area within; located in the north wall of north screen well 12 ft. above the floor between strap plates 72 and 73.

167.

Rust stains -

orange rust on surface in area of north vall of north screen well 15 ft. above floor between strap plates 69 and 70.

168.

Rust stains orange rust on surface over an area of north wail of north screen well 15 ft. above the floor between strap plates 70 and 71.

169.

Extensive surface rust stains between strap plates 69 and 70.

170.

Spalled concrete area, 5 ft. x 3 ft. red and orange surface rust color with black rust color immediately below surface. Spall appears to be 1hdeep and surface breaks away easily with white chalky color below 1/8c desounds hollow in a 6 inch diameter area within total area.

ay be from previous chipped area #Y which was patched with different material than original. Located 3 ft. east of west bar screen 4 ft.

above strap plate in north wall of north screen well.

171.

Spall area, 2-1/2 ft. by 3 ft. length to depth of 1/8 inch orange rust surface color located in north vail of north screen well 12 ft. above strap plates and 6 ft. west of east traveling screen. Sounds solid.

Does not appear significant.

172.

orange stains widespread - light 15 ft. above strap plates - no other irregularity. North wall of north screen well.

NORTH WALL NORTH SCREEN WELL-BETWEEN TRAVELING SCREEN AND EAST SCREEN WELL WWALL.

173.

Heavy rust spot, 2 inch diameter protruding 1-1/2" above surface located 14 inches above ledge which is at elevation 7 ft. and 13 inches west of east wall in north wall of north screen well.

Heavy red rust spot, 6" triangular shape at ledge at elevation-7 and 7 inches west of east wall on north wall of north screen well.

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Page 24 of 33 Rust spot, 1" diameter of red and black rust 14 inches above ledge at elevation-7 and 2-1/2 inches east of gate slot on north wall of north screen well.

174.

Red rust spot, 1-1/2 inch diameter located 5 ft. above ledge at elevation-7 and 5 inches west of east wall on north wall of north screen well.

Rust spot, red and black rust 1-1/2 inches in diameter protrudes rust 3/4 inches from surface 2 inches east of east gate slot and 5 ft.

above ledge at elevation-7 on north wall of north screen well.

175.

Rebar exposed and heavily rusted located west side of strap plate

1. 34:

One bar at 36 inches below ceiling and other 20 inches below ceiling. Must be steel transported from elsekhere.

SOUTH PUMP BAY 176.

Orange to red rust spot located 5 ft. above the floor 1-1/2 ft. vest of strap plate #35.

Spot runs 6 inches vertically by 3 inches high and protrudes rust at about 2 inches from surface. This corresponds to previous survey note No. 120 in the north wall of south pump bay.

177.

2 ft. x 5 inch x 3 inch concrete piece was removed from the floor of south pump bay. Piece came from the center piece of double slot of traveling screen.

178.

Rust spot, 2-1/2 ft. long vertically by up to 5 inches wide of dark red and black rust color located in the north wall of the south pump bay at 3 inches west of strap plate #36 and 8 ft. above the floor.

179.

Rust spot, 3-1/2 inches diameter protruded 1-1/2 inches from surface 1 inch eat of strap plate #48 and 3-1/2 ft. above floor on south wall of south pump bay.

180.

Rust spot, 3 inches diameter 3 inches below the ceiling 20 inches west of strap plate #50 on south wall of south pump bay.

181.

Rust stains and rust deposits in and around the grout at the top of strap plate #51 on south wall of south pump bay.

182.

Rust spot of 1-1/2 inch diameter 1 ft. below ceiling and 1 inch west of strap plate #51 on south wall of south pump bay corresponding to previous survey note #117.

183.

Rust spot running 8 inches vertically by 5 inches wide 15 inches east of strap plate #54, 2 ft. below the ceiling corresponding to previous survey note #114 on south wall of south pump bay.

184.

Rust spot, 2" diameter just east of strap plate #55 at 8 ft. below the ceiling on south wall of south pump bay.

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Page 25 of 33 185.

Rust spot - 1 inch diameter at the top of strap plate #57 on south wall of south pump bay.

186.

Rust spot, 3 inch diameter located 10 inches above the floor just east of strap plate #59 on south wall of south pump bay.

EAST WALL OF SCREEN WELLS 187.

Rust spots up to 3 inches in diameter and several cracks in the west face of ledge all along the west face of ledge that is between elevation-7 and -11 ft. at east wall of south screen well.

188.

White chalky deposit running up from the ledge at elevation-7 ft.

extending upward 6 ft. at the south corner on the east wall of the south screen well.

189.

Rust spot, 1-1/2 inches diameter 4 ft. above the ledge at elevation-?

and 6 ft. north of south wall on the east wall of the south screen well.

190.

Rust spot, 4 inches diameter of red and brown rust 5-1/2 ft. above ledge at elevation-7 and 6 ft. south of north wall on the east wall of the south screen well.

191.

Strip of reddish brown rust 1 ft. long and 1-1/2 inches wide 6-1/2 ft.

above ledge of elevation-7 and 7 ft. south of north wall on east wall of south screen well.

192.

Two rust spots of 1-1/2 inches diameter each 9 ft. above ledge at elevation-7 and 6 ft. north of south wall on the east wall of the south screen well.

193.

Rust spots and cracks along the west face of the ledge at elevation-7 on the east wall of the north screen well.

194.

Rust spot, 1 inch diameter at corner with ledge 9 inches north of south wall on the east wall of the north screen well.

195.

Crack diagonally down and to the south from 3-1/2 ft. above the ledge and 2 ft. from the north wall on the east wall of the north screen well. Crack is clean of rust and sounds solid.

SOUTH WALL OF NORTH SCREEN WELL 196.

Two rust spots - 1 inch diameter each and of dark reddish rust located 2 ft. west of east gate slot and 11 ft. above the ledge at elevation

-7 on the south wall of the North screen well.

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Page 26 of 33 197.

Rust spot, 5 inches vertically by 3 inches wide located 10 inches west of east gate slot at 11 ft. above the ledge at elevation-7 on the south vall of the north screen well.

198.

Rust spot in corner 1 inch wide by 4 inches long runs vertically up corner from 16 inches above ledge at elevation-7 ft. on north wall of south screen well in corner with east wall.

SOUTH SCREEN WELL 199.

Rust strip, 3/4 inch width by 2-1/2 inches long located 2-1/2 ft above ledge at elevation-7 4-1/2 inches from east wall on the north wall of the south screen well.

200.

Crack with dark red to black rust stains 4 inches long runs to east wall from 3-1/2 inches east of gate slot located 3-1/2 ft. above ledge at elevation-7 ft. on north wall of south screen well.

201.

Rust spot at east gate slot 3 inches vertically by 2-1/2 inches width located 5-1/2 ft.. above the elevation-7 ft. ledge.

202.

Rust spot, 3 inch diameter 2 inches east of east gate slot and 8-1/2 ft. above the elevation-7 ft. ledge.

203.

Rust spot, 3 inches wide by 6 inches long located 1 ft. west of traveling screen slot and 5-1/2 above elevation-7 ft. ledge on the north wall of south screen well.

204.

Rust spot, 3 inches wide by 7 inches long located 10 inches west of screen slot 4 ft. above the elevation-7 ft. ledge 10 inches west of east gate slot on the north wall of the south screen well.

205.

Rust spot, 4 inches wide, 6 inches long located 10 inches west from traveling screen slot and 5-1/2 ft. above elevation-7 ft. ledge on the north wall of the south screen well.

206.

Rust spot - hollow sounding 1-1/2 ft. wide by 2" high located 15 inches above strap plates 1-1/2 ft. east of bar screen on north wall of south screen well.

207.

Rust spot, 2 inches diameter located 18 inches west of traveling screen slot and 9-1/2 ft. above elevation-7 ft. ledge on the north wall of south -screen well.

208.

Rust spot, 2 inches diameter 20 inches east of traveling screen double slot and 8 ft. above elevation-7 ft. ledge on north wall of south screen well.

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Page 27 of 33 209.

Rust spot, 2 inches diameter located 4 ft. east of traveling screen double slot and 10 ft. above elevation-7 ft. ledge on north wall of south screen vell.

210.

Rust strip, 20 inches high and varies in width from 2 inches to 4 inches located 8-1/2 ft. above elevation-7 ft. ledge and 2-1/2 ft.

west of east gate slot in the north wall of south screen well. Hollow sound along the strip.

211.

Two rust spots - one of 2-1/2 inch diameter, one 12 inches wide by 6 inches high located 6 inches west of east gate slot 8 ft. above elevation-7 ft. ledge on north wall of south screen well. Hollow sound.

212.

Rust spot, 8 inches high by 3-1/2 inches wide located 3 inches vest of east gate slot 8 inches below elevation-11 ft. (bottom of ledge) on south wall of south screen well. Some hollow sounding.

213.

Rust spot - same as previous survey note #101.

214.

Rust spot, 3 inches diameter located 2 ft. east of west wall and 2 ft.

above strap plates in north wall of south screen well.

215.

Crack, 3-1/2 inches long, orange rust color located 5 ft. above strap plates 2-1/2 inches east of west gate slot on north wall of south screen well.

SOUTH WALL OF NORTH SCREEN WELL 216.

Rust spot, 2 inches diameter located 1 ft. above strap plates just east of west gate slot in south wall of north screen well.

217.

Rust spot, 2-1/2 inch diameter located 3 ft. above strap plates, 18 inches east of west wall on the south wall of north screen well.

218.

Rust spot, 1-1/2 inch diameter located 2-1/2 ft. above the floor 5 inches east of traveling bar screen on the south wall of north screen well.

219.

Rust spot, 3 inches diameter of bright orange with yellow rust exuding located 2-1/2 ft. above floor and 3 ft. east of strap plate No. 77 on south wall of north screen well.

220.

Rust spot, 3 inches diameter orange and exuding yellow rust located 5 ft. above the floor and 1-1/2 ft. east of strap plate No. 77.

Light orange stains throughout this area of wall on south wall of north screen well.

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Page 28 of 33 221.

Rust spot, 1/2 inch diameter, exuding bright orange rust located 3-1/2 ft. west of east screen, 25 ft. above floor on south wall of north screen well.

222.

Three rust spots 3 inch diameter each and dark rust stains over area located 3 ft. east of west bar screen and 1 - ft. above strap plates.

Sounds solid on south wall of north screen well.

223.

Rust spot, 2 inch diameter, located 5 ft. east of west bar screen, 10 ft. above strap plates on south wall of north screen well.

CEILING OF CROSSOVER 224.

Rust spot, 2-1/2 inch diameter upper ceiling of crossover section 12 ft. south of north wall in corner with west wall located in upper ceiling of crossover.

225.

Hairline crack, upper ceiling of crossover 12 ft. south of north wall and 5 ft. east of west wall.

NORTH WALL OF NORTH PUMP WELL 226.

Rust spot of bright orange with bright yellow rust exuding from the center; 3 inch diameter and 1-1/2 inches protruding from the surface located 4 inches east of strap plate no. 2 at 4 feet above the floor on the north wall of the north pump well.

227.

Rust spot of bright orange; 3 inch diameter located at the east edge of strap plate no. 3 and 10 feet above the floor on the north wall of the north pump well.

228.

Rust spot of orange color; 1 foot vertical length and 6 inches wide and projecting 1 inch from the wall surface located 2 feet east of strap plate no. 3 and 10 feet above the floor on the north wall of the north pump well.

229.

Crack in the concrete, 6-1/2 inches horizontal length and up to 1/4 inch wide located 8 inches east of strap plate no. 3 and 9 feet above the floor on the north wall of the north pump well.

230.

Rust spot, 1 inch in diameter located at the west edge of strap plate no. 4 and 10 feet above the floor on the north wall of the north pump well.

231.

Rust spot, 3 inches diameter located at the west edge of strap plate No. 4 and 9-1/2 feet above the floor on the north wall of the north pump well.

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Page 29 of 33 232.

Rust spot of orange with yellow center; of 2-1/2 inches diameter and projecting 2 inches from wall surface located 2 inches east of strap plate No. 5 and 11 feet above the floor on the north wall of the north pump well.

233.

Rust spot, 2 inches diameter, located 14 inches east of strap plate No. 5 and 11 feet above the floor on the north wall of the north pump well.

234.

Rust spot, 1-1/2 inches diameter of orange color projecting 1 inch from the wall surface located 4 inches east of strap plate no. 6 and 5 feet below the ceiling on the north wall of the north pump well.

235.

Rust stains of 6 inches in diameter; when surface is chipped concrete is clean underneath; located 3 inches east ofestrap plate No. 6 and 10 feet above the floor on the north wall of the north pump well (see previous 63A).

236.

Rust spot of 3 inches by 2 inches projecting 1-1/2 inches from wall surface located 4 inches west of strap plate No. 7 and 11 feet above the floor on the north wall of north pump well.

237.

Rust spot of 4-1/2 inches diameter projecting 1 inch from wall surface located 10 inches west of strap plate No. 7 and 2 feet above the floor on the north wall of the north pump well.

238.

Rust spot of orange color; 3-3/4 inches diameter projecting 1 inch from wall surface located 9 inches east of strap plate No. 7 and 11 feet above the floor on the north wall of north pump well.

239.

Rust spot along form line of 3 inches diameter and 1-1/2 inch projection from wall surface located 21 inches east of strap plate No.

7 and 10 feet above the floor on the north wall of north pump well.

240.

Rust spot, 4 inches by 2-1/2 inches and projecting 2 inches from wall surface located 13 inches east of strap plate No. 8 and 5 feet below the ceiling on the north wall of the north pump well.

241.

Rust spot and spall 1/2 inch by 1 inch with hole in center of 1 inch depth of orange rust; opened hole to 3 inches diameter with black rust deposit in hole with bubbles escaping from hole; located 17 inches east of strap plate No. 8 and 10 feet above the floor. Sounded solid.

242.

Rust stain, orange, and heavy rust spot of 11 inches long by 6 inches wide projecting 1-3/4 inches from wall surface located 18 inches west of strap plate No. 9 and 5 feet above the floor on the north wall of north pump well.

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Page 30 of 33 243.

Rust spot, 3 inches by 1-1/2 inches, orange with yellow center and yellow at depth, located 19 inches east of strap plate No. 10 and 6 inches above the floor on the north wall of the north pump well.

EAST WALL OF NORTH PUMP WELL 244.

Rust spot, 6 inches by 5 inches and projecting 3 inches from wall surface of bright orange and brownish yellow located 2 feet south of strap plate No. 15 and 10 feet above the floor on the east wall of the north pump well.

245.

Rust spot, 1 inch diameter and projecting 1/2 inch from wall surface located 1 inch south of strap plate No. 16 an1 3 feet above the floor on the east wall of the north pump well.

SOUTH WALL OF NORTH PUMP WELL 246.

Rust spot, 2 inch diameter and projecting 1/2 inch from wall surface, orange rust, located 6 inches east of strap plate No. 26 and 4 feet above the floor on the south wall of the north pump well.

247.

Rust spot, 3-1/2 inches by 2-1/2 inches projecting 1 inch from wall surface, orange with yellow center located 3 inches west of strap plate No. 26 and 5 feet above the floor on the south wall of north pump well.

248.

Rust spot, 3-1/2 inches by 2-1/2 inches projecting 1/4 inch from wall surface located 2 inches west of strap plate No. 26 and 10 feet above the floor on the south wall of the north pump well.

249.

Rust spots -

(4) in a horizontal line, all 8 feet above the floor as follows:

o 3 inch diameter and projecting 1-1/2 inches from wall surface o

3 inch diameter and projecting 1 inch from wall surface o

2-1/2 inch diameter and projecting 1/4 inch from wall surface o

7-1/2 inches by 4-1/2 inches projecting 2 inches from wall surface located in a horizontal line from 1/2 inches west of strap plate no.

25 to 21 inches west of strap plate no. 25 and all 8 feet above the floor on the south wall of the north pump well.

250.

Rust spot, 2 inches diameter and projecting 1/2 inch from wall surface, located 12 inches east of strap plate no. 25 and 9 feet above the floor on the south wall of the north pump well.

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Page 31 of 33 251.

Rust spot, 2 inch diameter and 1/2 inch projecting from wall surface located 3 feet east of strap plate No. 25 and 2-1/2 feet above the floor on the south wall of the north pump well.

252.

Rust spot, 1-1/2 inch diameter and projecting 3/4 inch from wall surface located 3 feet east of strap plate No. 25 and 5 inches above the floor on the south wall of north pump well.

253.

Rust spot, 2 inches diameter projecting 1 inch from wall surface located 5 feet east of strap plate No. 25, 2-1/2 feet above the floor on the south wall of north pump well.

254.

Rust spot, orange, 2 inch diameter projecting 1/2 inch from wall surface located 2 feet west of strap plate No. 24 and 4 feet above the floor on the south wall of north pump well.

255.

Rust spot, orange 2-1/4 inch diameter and projecting 1 inch from wall surface located 1-1/2 feet west of strap plate No. 24 and 10 feet above the floor on the south wall of north pump well.

256..

Rust spot, orange, 1 inch diameter projecting 3/4 inch from wall surface located 2 feet west of strap plate No. 24 and 1-1/2 foot below the ceiling on the south wall of the north pump well.

257.

Rust spot, 6 inches by 3 inches and projecting 2 inches from wall surface located 1-1/2 feet east of strap plate No. 24 and 1 foot below the ceiling on the south wall of the north pump well (see previous 63D).

258.

Rust spot, bright orange, 2 inch diameter projecting 1 inch from wall surface located 2-1/2 feet east of strap plate No. 23 and 8-1/2 feet above floor on south wall of north pump well.

259.

Rust stain over the surface of the wall in an area east of strap plate No. 23 on the south wall of north pump well.

260.

Rust spot, orange, 4 inches by 3 inches and projecting 1-1/2 inches from wall surface located 2 inches west of strap plate No. 22 and 10 feet above floor on south wall of north pump well.

261.

Rust spot, 6-1/2 inches by 6 inches projecting 1-1/2 inches from wall surface located at the east edge of strap plate No. 22 and 10 feet above the floor on the south wall of north pump well.

262.

Rust spot, bright orange, 6-1/2 inches diameter projecting 2 inches from wall surface located 1-1/2 feet east of strap plate No. 22 and 11 feet above the floor on south wall of north pump well.

263.

Rust spot, 7 inches by 5 inches projecting 2 inches from wall surface located 1-3/4 feet east of strap plate No. 22 and 11 feet above the floor (adjacent to no. 262 above) on the south wall of north pump well.

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Page 32 of 33 264.

Rust spot, orange rust, 3 inches diameter projecting 1-1/4 inches from wall surface located 1-1/2 feet east of strap plate No. 22 and 1 foot below the ceiling on south wall of north pump well.

265.

Rust spot, orange, 2 inch diameter and projecting 1 inch from wall surface located 2 feet east of strap plate No. 21 and 8 feet above the floor on south wall of north pump well.

266.

Rust spot, 4 inches by 6 inches projecting 1 inch from wall surface located 3 feet east of strap plate No. 21 and 8 feet above the floor on the south wall of north pump well.

267.

Rust spot, 2 inches diameter located 5 inches east of strap plate No.

21 and 4 feet above the floor on the south wall of north pump well.

268.

Rust spot of orange rust, 6 inches by 2-1/2 inches projecting-1-1/2 inches from wall surface located 9 inches west of strap plate No. 21 and 3 feet above the floor on the south wall of the north pump well.

269.

Rust spot, 2 inches diameter projecting 1 inch from wall surface located 5 inches east of strap plate No. 21 and 9 inches above the floor on the south wall of the north pump well.

270.

Rust spot, orange rust, 2 inches diameter projecting 2 inches from wall surface located 1 foot east of strap plate No. 20 and 8 inches above the floor on the south wall of north pump well.

271.

Rust spot, 6 inches diameter projecting 1-1/2 inches from wall surface, located 15 inches west of strap plate No. 20 and 6 feet above the floor on the south wall of the north pump well.

272.

Rust spot, 3 inches by 1 inch projecting 1/2 inch from wall surface located 3 inches east of strap plate No. 19 and 5 feet below the ceiling on the south wall of north pump well.

273.

Rust spot, orange rust, 5 inches by 2 inches projecting 1-1/2 inches from wall surface located 3 inches east of strap plate No. 19 and 7 feet above the floor on the south wall of the north pump well.

EAST WALL OF NORTH PUMP WELL 274.

Rust spot, bright orange rust, 3 inches diameter projecting 1-1/2 inches from the wall surface located 2 feet north of strap plate No.

18, 10 feet above the floor on the east wall of the north pump well.

275.

Rust spot, orange rust, 1-1/2 inches diameter projecting 1/2 inch from wall surface located 2 inches north of strap plate No. 17 and 12 feet above the floor on the east wall of the north pump well.

OPDSO754

Page 33 of 33 276.

Rust stain over the surface of the east vall directly behind the circulating vaterpump in the north pump well.

NORTH WALL 277.

Bright orange rust spot, 4" dia., 3-1/2 ft. above floor, 3 ft. west of gate No. 9 slot in North wall at crossover. (Visual only).

278.

Bright red rust spot, 4" dia., 3 ft. above floor, 4 ft. vest of gate No. 9 slot in North wall at crossover. (Visual only).

279.

Rust spot, 18" 0, 10 ft. west of Gate No. 9 slot 2' above floor; area of previous core drill No. 15.

(Visual only),

280.

Crack from floor extends vertically up for 2 ft. on vest side of Gate No. 9 slot in the North wall.

0 OPDSO7 54

APPENDIX B

REFERENCE HALF-CELL READINGS. SECOND SURVEILLANCE.

Page DAT OF

REFERENCE HALF*CELL :

0AT OFmLOCATION READING

MEASUREMENTS:

OF HALF-CELL MEASUREMENTS 12/3/88 BASE SLAB. INTAKE TUNNEL

0.468

---

-I.......

12/20/88 BASE SLAB. NORTH PULP WELL

-0.491

""8.....*..--*--------..........

12/3/88 BASE SLAB. SOUTH PUMP WELL

-0.4725 12/3/88 ROOF SLAB.

INTAKE TUNNEL

-0.466 12/20/88 ROOF SLAB. NORTH PUMP WELL

-0.490 12/3/88 FLOOR SLAB. SOUTH PUMP WELL

-0.4725 12/3/88 NORTH WALL.

INTAKE TUNNEL

-0.465 UP TO SCREEN WELL 12/4/88 NORTH WALL.

LOWER PORTION

-0.464 OF SCREEN WELL 12/3/88 NORTH WALL.

UPPER PORTION

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PUMP WELL

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PUMP WELL AND

-0.4725 SCREEN WELL 12/5/88 INTERMEDIATE WALL. SOUTH FACE

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Page 2 REFERENCE HALF-CELL READINGS. SECOND SURVEILLANCE.

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