agus 6 flooding executive brief

8/3/2019 Agus 6 Flooding Executive Brief

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MEMORANDUM

FOR : A. F. SUEZO, JR.

OIC-VP, Mindanao Generation

SUBJECT : Fact Finding Report Re Agus 6 HEP Sump Pit Flooding

I. Administrative Basis:A. Memo Order 20121-0029 dated 23 August 2011B. Memo for Mr. A. F. SUEZO, JR. Dated 23 & 26 September 2011-10-11C. Memo for Mr. J. S. PATES, Jr. Dated 03 October 2011


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Executive Brief:

I. Background:On the basis of the spot report dated August 21, 2011 received at the Office of the VP

regarding the plant shutdown of Agus 6 units 3, 4 and 5 due to excessive flooding at the

sump pit area, the OIC VP created a Task Force through Memo Order No, 2011-0029 dated

August 23, 2011 with a mandate to:

a. Determine the root cause of the flooding at the sump pit at Agus 6 HEP;b. Determine the administrative liability of anyone, if there is any; andc. Submit report and recommend corrective action on the incident to then OIC VP Atty. E.

L. Ramirez.

II. Factual Findings:An ocular inspection was conducted by the task force at the Agus 6 sump pit for units 3, 4 &

5 last September 23, 2011. The inspection disclosed the following:

1. Water seepages from turbine pits/shaft seals of units 3, 4 & 5 were noted. Units 3 & 4discharges were observed to be strong while unit no. 5 was moderate. Other sources of

seepages were also noted coming from the draft tubes of units 3, 4,& 5 and the

upstream side wall of the basement floor.

2. One (1) out of the three (3) sump pumps were found without electric motor.3. The centrifugal pump was also without electric motor.4. One (1) unit submersible pump which was reported to be coming from Agus 2 HEP was

still inplace at sump pit and operating.5. The two (2) regularly installed submersible pumps at the sump pit were not in-place.6. One (1) sump pump was operating.7. The two (2) jet pumps at the jet pit were operational at the time of the inspection.An Interview with the operations personnel (Mr. Macario M. Zabate, Equipment Operator D,

Rogelio M. Ambito, Equipment Operator C and was conducted last September 26, 2011 at

Agus 7 HEP conference room. The interview disclosed the following:

1. At the main sump pit there were three (3) sump pumps (2 units at 300 GPM and 1 unitat 600 GPM); one (1) unit centrifugal pump at 40 GPM; two (2) submersible pumps ( 1

unit at 112GPM and the other is 160 GPM).

2. At the jet pit, there were installed two (2) jet pumps at 300 GPM each.3. Of the three sump pumps one unit was pulled out before the incident and of the

remaining two units, one that was supposedly functioning but found later had defective

impeller and the other unit was not functioning.

4. The centrifugal pump was functional but the capacity was not sufficient to control thewater level at the sump pit. But according to Messrs. Ambito and Sinal, they suspected

that this pump was defective even before the incident.


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5. Of the two submersible pumps,One unit was defective and the other unit wasoperational but can not be used due to detached discharge hose. According to Mr. Sinal

he operated the operational submersible pump but it failed to actuate/ operate.

6. Of the two jet pumps, one was operational according to Mr. Zabate and the other onewas not operational. However, the operational one was later found out to have clogged

suction pipe.Mr. Zabate attempted to manipulate the control valve of Jet Pump No. 2 to

no avail.

An interview on October 5, 2011 at OVP conference room with Mr. Alfredo Q. Andaloc,

Operations Superintendent-on-duty at the time of incident disclosed the conditions of the

water pumps before the incident were as follows:

1. Weeks before the incident, there was already an observation wherein the sump pit hadan abnormal rising of water level.

2. The discharge hose of the submersible pump that was operational was detached fromthe unit for reason that it had traversed through the turbine floor to the tailrace area

and it did not look good during the conduct of IMS audit by TUV SUD auditors. The said

hose was not reinstalled back to the unit making the unit inutile after it was removed onAugust 6, 2011.

3. He noted that during his conduct of the patrol check at 3 PM of August 20, 2011, thecentrifugal pump was operational.

4. Jet pump no. 1 was operational but with leakage making it ineffective to be relied with.The other pump was operational but later bogged down due to clogging.

5. The centrifugal pump was functional but the suction pipe was damaged. Mr. Andalocsuspected that when the pump was operated the gate valve was probably at closed

position which resulted to that damage.

6. The condition of the two (2) submersible pumps were such that one unit was defectiveand the other unit was operational but can not be used for dewatering due to detached

discharge hose.7. The defects noted on the condition of the water pumps were not recorded nor reported

in the Patrol Check List and likewise were not issued with Corrective Maintenance Work

Order (CMWO) for appropriate corrective action. The recorded issuance of CMWO were

last December 2010 yet (CIP: CMWO No. AG63-10-0051 for sump pump no. 3 and

CMWO No. AG63-10-0049 on jet pump no. 1.

To balance the course of the investigation, an interview with the maintenance personnel

(Jose S. Pates, Jr., Plant O/M Manager, Manuel A. Manuta, Mechanical Superintendent, Edwin L.

Tadulan, I&C Maintenance Superintendent and Abraham C. Acoba, Electrical Maintenance

Superintendent ) was also conducted last October 5, 2011 at OVP conference room. The task force was

informed of the following:

1. The float switches at the sump pit and jet pit were not operational, including its alarm system.2. On the status of the water pumps: three (3) sump pumps were all operational. Records show

that there were no adverse findings noted in the implementation of PMWO No. AG63-11-0566

that was implemented on July 11, 2011 for sump pump no. 2; PMWO No. AG61-11-0532 for

sump pump motor no. 1 that was implemented on July 12, 2011; PMWO No. AG61-11-0527 that

was implemented for Portable Dewatering Pump motor on July 12, 2011; PMWO No. AG61-11-

0526 that was implemented on July 11, 2011 for Sump pump motor no. 2; PMWO No. AG63-11-


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0397 that was implemented on May 10, 2011 for Sump Pump Motor No. 3 (submersible);

PMWO No. AG63-11-390 that was impemented on May 10, 2011 for Sump Pump Motor No. 1

(centrifugal); PMWO No. AG61-11-0004 that was implemented on April 21, 2011 for Sump Pump

Motor No. 1; PMWO No. AG61-11-0044 that was implemented on January 17, 2011 for Portable

Dewatering Pump Motor; PMWO No. AG61-11-0043 that was implemented January 18, 2011 for

Sump Pump Motor No. 2; PMWO No. AG63-11-0041 that was implemented last January 21,

2011 for Sump Pump Motor No. 2. PMWO Nos. AG63-11-0455 and AG63-11-0203 that were

implemented on June 6, 2011 and March 7, 2011, respectively for the cleaning of strainer of Jet

Pump No. 1.

a. Root Causeb. Administrative Liability

III. RecommendationsIV.

agus 6 flooding executive brief

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