ML092730349

Task Interface Agreement (TIA) - Unacceptable Preconditioning of Safety-Related Pressure Switches During Required Surveillance Testing at Monticello (TIA 2009-006)

ML092730349
Person / Time
Site:	Monticello
Issue date:	09/30/2009
From:	Shear G Division Reactor Projects III
To:	Blount T Division of Policy and Rulemaking
References
tia 2009-006
Download: ML092730349 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION REGION III 2443 WARRENVILLE ROAD, SUITE 210 LISLE, IL 60532-4352 September 30, 2009 MEMORANDUM TO: Thomas B. Blount, Deputy Director Division of Policy and Rulemaking Office of Nuclear Reactor Regulation FROM: Gary L. Shear, Deputy Director /RA/

Division of Reactor Projects Region III

SUBJECT:

TASK INTERFACE AGREEMENT (TIA) - UNACCEPTABLE PRECONDITIONING OF SAFETY-RELATED PRESSURE SWITCHES DURING REQUIRED SURVEILLANCE TESTING AT MONTICELLO (TIA2009-006)

This Task Interface Agreement (TIA) documents the regulatory position as determined by Region III and the Office of Nuclear Reactor Regulation regarding the unacceptable preconditioning of safety-related pressure switches during Technical Specification required surveillance testing at the Monticello Nuclear Generating Plant.

On July 7, 2008, the Monticello resident inspectors observed a surveillance which tests and calibrates the pressure switches for the Main Steam Low Press Group I isolation. These pressure switches are normally pressurized (>815#), with open contacts. To test the pressure switches, the technician:

• isolated the pressure switch from the pressure source;

• uncapped the test connection [which depressurizes the pressure switch and causes the pressure switch contacts to close];

• hooked up the test pressure source to the test fitting;

• increased test pressure until the pressure switch resets [contacts open];

• recorded the RESET test data;

• bled off the test pressure until the pressure switch trips [contacts close];

• recorded the AS-FOUND trip setpoint; and

• removed test equipment and restored pressure switch to operation.

CONTACT: Christian Scott, Reactor Engineer, Region III (630) 829-9838 Christopher Thomas, Senior Resident Inspector, Monticello (763) 295-2066

T. Blount On July 9, 2008, the resident inspectors observed a surveillance which tests and calibrates the pressure switches associated with the Turbine Control Valve Fast Closure function. These pressure switches are normally pressurized (approximately 250#), with closed contacts. To test the pressure switches, the technician:

• isolated the pressure switch from the pressure source;

• uncapped the test connection [which depressurizes the pressure switch and causes the pressure switch contacts to open];

• hooked up the test pressure source to the test fitting;

• increased test pressure until the pressure switch resets [contacts closed];

• recorded the RESET test data;

• bled off the test pressure until the pressure switch trips [contacts open];

• recorded the AS-FOUND trip setpoint; and

• removed test equipment and restored pressure switch to operation.

During each of the surveillances, the pressure switch was fully cycled before the AS-FOUND trip setpoint data was recorded. Further evaluation of the issue by the inspectors revealed that this method of testing pressure switches, which resulted in fully cycling the pressure switches prior to obtaining AS-FOUND test data, was common at Monticello and potentially impacted approximately 30 pressure switches that were required by technical specifications.

Licensee Position:

Since first being presented with this issue in July 2008, the licensees engineering evaluations have led them to several positions. These positions have included that it is not preconditioning and that it is acceptable preconditioning. The licensee has benchmarked several other licensees pressure switch testing methodologies and has not reached a consensus on the preconditioning question. The licensees current position is that the issue is potentially a generic industry issue and should be addressed as such in regulatory space.

Applicable Regulatory Position:

The limited regulatory guidance on the topic of preconditioning resides primarily in Information Notice 97-16, Preconditioning of Plant Structures, Systems, and Components Before ASME Code Inservice Testing of Technical Specification Surveillance Testing and Inspection Manual Chapter 9900, Maintenance - Preconditioning of Structures, Systems and Components Before Determining Operability.

The current pressure switch testing methodology affects approximately 30 pressure switches, which are relied upon to initiate technical specification required safety functions. These technical specification required functions include:

• condenser low vacuum scram [Technical Requirements Manual (TRM) 3.3.1.1];

• HPCI turbine steam supply low pressure isolation [TS 3.3.6.1, Table 3.3.6.1-1];

• RCIC turbine steam supply low pressure isolation [TS 3.3.6.1, Table 3.3.6.1-1];

• low reactor pressure pump start permit [TS 3.3.5.1, Table 3.3.5.1-1];

• LPCI recirculation loop select interlock [TS 3.3.5.1, Table 3.3.5.1-1];

T. Blount

• reactor high pressure shutdown cooling isolation [TS 3.3.6.1, Table 3.3.6.1-1];

• low reactor pressure ECCS valve permit [TS 3.3.5.1, Table 3.3.5.1-1];

• main steam line low pressure isolation [TS 3.3.6.1, Table 3.3.6.1-1]; and

• turbine control valve fast closure scram [TS 3.3.1.1, Table 3.3.1.1-1].

The existing licensee pressure switch testing methodology ensures operability of the pressure switches subsequent to the performance of the applicable surveillance procedure since the required AS-LEFT pressure switch setpoint is adjusted (if required) prior to the completion of the surveillance. The problem with the current pressure switch testing methodology is that it potentially masks existing conditions (sticking contacts, mechanical binding, setpoint drift, etc.),

which could mask existing operability because the pressure switch being tested is fully cycled prior to obtaining AS-FOUND trip setpoint data.

Inspection Manual Chapter 9900 states, in part, that unacceptable preconditioning is defined as the alteration, variation, manipulation, or adjustment of the physical condition of a Structure, System, and Component (SSC) before or during technical specification surveillance or ASME Code testing that will alter one or more of an SSCs operational parameters which results in acceptable test results. Such changes could mask the actual as-found condition of the SSC and possibly result in an inability to verify the operability of the SSC. In addition, unacceptable preconditioning could make it difficult to determine whether the SSC would perform its intended function during an event in which the SSC might be needed.

Therefore, the applicable regulatory position, in the absence of an appropriate licensee engineering evaluation which justifies the preconditioning as acceptable, is that a surveillance testing methodology which cycles a pressure switch prior to obtaining AS-FOUND trip setpoint data constitutes unacceptable preconditioning of the pressure switch.

==

Conclusion:==

The licensees surveillance testing methodology, which cycles a pressure switch prior to obtaining AS-FOUND trip setpoint data, constitutes unacceptable preconditioning of the pressure switch. Absent an engineering evaluation, the current surveillance testing methodology is unacceptable and must be changed so that the applicable pressure switches are not cycled prior to obtaining AS-FOUND trip setpoint data.

Docket: 50-263 DISTRIBUTION:

See next page

Memo to T. Blount from G. Shear dated September 30, 2009

SUBJECT:

TASK INTERFACE AGREEMENT (TIA) - UNACCEPTABLE PRECONDITIONING OF SAFETY-RELATED PRESSURE SWITCHES DURING REQUIRED SURVEILLANCE TESTING AT MONTICELLO (TIA2009-006)

DISTRIBUTION:

RidsOgcMailCenter RidsNrrMailCenter RidsRgn1MailCenter RidsRgn2MailCenter RidsRgn3MailCenter RidsRgn4MailCenter RidsNrrDpr RidsNrrDprPspb RidsNrrDirsItsb RidsNrrDeEicb RidsNrrDirsIrib S. West S. Rosenberg, C/NRR/PSPB E. Bowman, PM/NRR/PSPB C. Schulten, NRR/ITSB P. Tam C. Thomas L. Haeg N. Shah C. Scott

T. Blount

• reactor high pressure shutdown cooling isolation [TS 3.3.6.1, Table 3.3.6.1-1];

• low reactor pressure ECCS valve permit [TS 3.3.5.1, Table 3.3.5.1-1];

• main steam line low pressure isolation [TS 3.3.6.1, Table 3.3.6.1-1]; and

• turbine control valve fast closure scram [TS 3.3.1.1, Table 3.3.1.1-1].

The existing licensee pressure switch testing methodology ensures operability of the pressure switches subsequent to the performance of the applicable surveillance procedure since the required AS-LEFT pressure switch setpoint is adjusted (if required) prior to the completion of the surveillance. The problem with the current pressure switch testing methodology is that it potentially masks existing conditions (sticking contacts, mechanical binding, setpoint drift, etc.),

which could mask existing operability because the pressure switch being tested is fully cycled prior to obtaining AS-FOUND trip setpoint data.

Inspection Manual Chapter 9900 states, in part, that unacceptable preconditioning is defined as the alteration, variation, manipulation, or adjustment of the physical condition of a Structure, System, and Component (SSC) before or during technical specification surveillance or ASME Code testing that will alter one or more of an SSCs operational parameters which results in acceptable test results. Such changes could mask the actual as-found condition of the SSC and possibly result in an inability to verify the operability of the SSC. In addition, unacceptable preconditioning could make it difficult to determine whether the SSC would perform its intended function during an event in which the SSC might be needed.

Therefore, the applicable regulatory position, in the absence of an appropriate licensee engineering evaluation which justifies the preconditioning as acceptable, is that a surveillance testing methodology which cycles a pressure switch prior to obtaining AS-FOUND trip setpoint data constitutes unacceptable preconditioning of the pressure switch.

==

Conclusion:==

The licensees surveillance testing methodology, which cycles a pressure switch prior to obtaining AS-FOUND trip setpoint data, constitutes unacceptable preconditioning of the pressure switch. Absent an engineering evaluation, the current surveillance testing methodology is unacceptable and must be changed so that the applicable pressure switches are not cycled prior to obtaining AS-FOUND trip setpoint data.

Docket: 50-263 DISTRIBUTION:

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