ML20085F610

AO AO-18-74:on 740901,primary Coolant Sys Pressurized While Primary Sys Temp Below Tech Spec Limit.Caused by Operator Error &/Or Procedure Deficiency.Procedural Change to Be Initiated

ML20085F610
Person / Time
Site:	Palisades
Issue date:	09/11/1974
From:	Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	US ATOMIC ENERGY COMMISSION (AEC)
References
AO-18-74, NUDOCS 8308230056
Download: ML20085F610 (3)

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Directorate of Licenalng Y/ '"a

, i l0 Docket 50-255 US Atomic Energy Commionion /d."j 73 \iq'h ' Re:License DPR-20 f

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Palianden Plant A0-18-74 Gentlemen:

Attached in Abnormal Occurrence Report A0-18-Th covering pressurization of the primary coolant system with a low system temperature. This violation involved plant procedures and had no adverse errect on plant equipment.

Yours very truly, Ralph B. Sewell (Signed)

DAB /mel Ralph B. Sewell Nuclear Licensing Administrator CC: JGKeppler, USAEC f

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• O O ABNORMAL OCCURRENCE REPORT Palisades Plant

1. Report Number: A0-18-Th, Docket 50-255

2. a. Report Date: September 11, 1974.

b. Occurrence Date: September 1, 1974.

3 Facility: Palisades Plant,

b. Identification of Occurrence: Pressurization of Primary Coolant System (PCS) when below the specified temperature.

5 Conditions Prior to Occurrence: Refueling shutdown.

6. Description of Occurrence: The pressure of the PCS was being increased to perform a leak test. The shift supervisor noted that the primary pressure was about 975 psia while the primary system temperature was only 150 F. Figure 3.1 of the Technical Specifications requires a temperature of 160 F to pressurize above 900 psia. This was, there-fore, a violation of a limiting condition of operation.

7 Designation of Apparent Cause: Operator error and/or procedure deficiency.

The operating procedures tell the operator to refer to the operating curve, prior to pressurization. There is, however, no mechanism to force the operator to follow the curve throughout the pressurization.

8. Analysis of Occurrence: A calculation was performed to demonstrate that the code allowable stress levels were not exceeded. The present vessel fluence was determined to be:

1.82 x 10 nyt 13 72 x 10 MWh p (2540MW x584 Days)*( 1 )*(24 Hours t

Present nyt - 0 70 x 10 6

Where 13.72 x 10 MWh is the cumulative thermal output to date and theratioofnyttoMkdistakenfromtheTechnicalSpecifications basis.

Figure 3.3 of the Technical Specifications shows that at 1.0 x 10 nyt, the increase in NDTT is 60 F. Using this conservative number and al-loving for 10 F temperature indication error, and 10 F for the initial NIyr temperature, the minimum temperature for pressurization at this point in vessel life would be:

, s %l b O O 2

8. Analysis of Occurrence: (Contd) 4 Initial NDTT 10 F NIYPT Shift 60*F Instrument Error 10 F 60 F NDTT Plus 60 lh0*F Thus, no actual vessel limitations have been violated. However, it is

deemed more important that the possibility existed that vessel limits could have been exceeded by the violation of the procedure.

Discussion with the shift supervisor revealed that the procedure manual in the control room was opened to the leak test procedure when he discovered the procedure violation. Step h of the prerequisites clearly specified that Figure Bl.1 was applicable and that Section Bl.2 of Technical Specifications was to.be referenced - via a caution note.

9 Corrective Action: No corrective action is required to the PCS since the limits violated were procedural and calculations have shown that

, physical limits were not exceeded.

To prevent recurrence of this incident, a procedural change will be initiated which will require that while a leak test is being performed, a pressure vs temperature curve will be plotted.

The particular operator and shift supervisor will be reprimanded for this occurrence, and the subject of procedure adherence will be stressed to all operators in a series of shift meetings.

10. Failure Data: Not applicable.

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