05000400/LER-1998-002, :on 980121,determined Ssps (P-11 Permissive) Testing Deficiency.Caused by Inadequate Review of Initial Ts.Will Revise & Perform Surveillance Test Procedures to Verify Operability of P-11 Permissive
| ML18016A406 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 04/30/1998 |
| From: | Verrilli M CAROLINA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML18016A405 | List:
|
| References | |
| LER-98-002, LER-98-2, NUDOCS 9805050234 | |
| Download: ML18016A406 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(x) |
| 4001998002R00 - NRC Website | |
text
NRC FORM 366 (4 95(
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
(See reverse for required number of digits/characters for each block)
APPROVED BY OMB NO. 3150 0104 EXPIRES 04/30/96 ESTIMATED BURDEN PER
RESPONSE
TO COMPLY NTH THIS MANDATORY INfORMATION COHECTION REOUES: 500 HRS.
REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSING PROCESS ANO FEO BACK TO INDUSTRY.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO tHE INFORMATION ANO RECORDS MAHAGEMENT BRANCH IT 6 F33). U.S. NUCLEAR REGULATORY COMMISSION, WASHIHGTON, OC 205550001, AND TO THE PAPERWORK REDUCTION PROJECT 0150.
OI04L OffICE OF MANAGEMENTANO BUDGET, WASHINGTON. OC 20503.
FACILITYNAME (11 Harris Nuc(ear Plant Unit-1 DOCKET NUMBER (2) 50-400 PAGE (3I 1 OF 3 TITLE (41 Solid State Protection System (P-11 Permissive) Testing Deficiency EVENT DATE (5)
MONTH OAY YEAR 1
21 98 LER NUMBER (6)
REPORT DATE (7)
YEAR SEOUENTML REVIS 0 MONTH NUMBER NUMBER 98
002
01 04 OAY YEAR 30 98 FACILITYNAME FACiLITY NAME OTHER FACILITIES INVOLVED(6)
DOCKET NUMBER DOCKET NUMBER 05000 OPERATING MODE (9)
POWER LEVEL (10) 100%
THIS REPORT IS SUBMITTED PUR SUANT TO THE REQUIREMENTS OF 10 CFR B: (Check one o 50.73(a) (2) (i) 50.73(a)(2)(ii) 20.2201 (b) 20.2203(a) (1) 20.2203(a)(2) (v) 20.2203(a) (3) (i) 50.73(a)(2)(iii) 50.73(a)(2) (iv) 20.2203(a) (3) (ii) 20.2203(a) (4) 20.2203(a) (2) (i) 20.2203(a) (2) (ii) 50.73(a)(2)(v) 50.36(c) (1) 20.2203(a)(2)(iii) 50.73(a)(2)(vii) 50.36(c) (2) 20.2203(a)(2)(iv)
LICENSEE CONTACT FOR THIS LER (12) r moro) (11) 50.73(a)(2)(viii) 50.73(a)(2)(x) 73.71 OTHER Specify in Abstract below or in NRC Form 366A NAME TELEPHONE NUMBER (Iee(ude Aiee Code(
Michael Verrilli Sr. Analyst - Licensing (9191 362-2303 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPROS
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPROS SUPPLEMENTAL REPORT EXPECTED (14)
YES (II yes, comple(e EXPECTED SUBMISSION DATE).
X NO EXPECTED SUBMISSION DATE (15)
MONTH OAY YEAR ABSTRACT (Limi(Io 1400 spaces, i.e., approxima(ely 15 single-spaced Typewritten lines) (16)
On January 21, 1998, with the plant at approximately 100% power in Mode I, Harris Plant Engineering personnel determined that Westinghouse Nuclear Safety Advisory Letter (NSAL)97-011 was applicable to thc HNP Solid State Protection System (SSPS).
This NSAL notified the industry that the current SSPS design did not allow'for complete overlap testing of the P-11 (Pressurizer Low Pressure)
Permissive function at power.
The P-11 Permissive provides the following functions below 2000 psig; (1) allows low pressurizer safety injection to be blocked, (2) allows steamline low pressure safety injection to be blocked, (3) blocks automatic operation of the pressurizer ower operated relief valves, (4) blocks the automatic open signal for the safety injection accumulators,
- 5) enables Main Steam Isolation on high steam pressure rate decrease.
NSAL 97-011 explained that the capability to test the P-11 Permissive from the process protection system at power is limited to the setpoint and does not include the overlap to the SSPS logic input relay since the bistable test switch is opened prior to testing the channel.
Opening the bistable test switch is required by the SSPS system design to satisfy the test logic for safety injection.
Since the SSPS input relay is de-energized above 2000 psig pressurizer, opening of the bistable test switch does not allow the input relay to change state during bistable setpoint verification; and tl)erefore, complete overlap testing for the SSPS input relay is not accomplished.
This condition constitutes a TS surveillance testing violation.
This condition was caused by an inadequate review of initial Tcchnical Specifications for consistency and the capability for testing SSPS permissive signals at power.
This revision provides new planned corrective actions, which will include revising and perl'orming surveillance test procedures to verify the operability of the P-11 Permissive.
9805050234 980430 PDR ADQCK 05000400 S
P TTP
NRC EORM 366A (4 95)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACILITYNAME (I)
Shearon Harris Nuclear Plant
~ Unit 41 DOCKET 50.400 LER NUMBER (6)
YEAR SEQUENTIAL NUMBER 98 002 REVISION NUMBER 01 PAGE (3) 2 OF 3
TEXT illmoce spocois ceooied. ose eddied)osl copies ol ill)CArm 3SQI (IT)
EVENT DESCRIPTION
On January 21, 1998, with the plant at approximately 100% power in Mode 1, Harris Plant Engineering personnel determined that Westinghouse Nuclear Safety Advisory Letter (NSAL)97-011 was applicable to the HNP Solid State Protection System (SSPS).
This NSAL notified the industry that the current SSPS design did not allow for complete overlap testing of the P-11 (Pressurizer Low Pressure)
Permissive.
Specifically, the monthly Analog Channel Operational Test (ACOT) required by Technical Specification (TS) 4.3.2.1 Table 4.3-2 Item 10a for the P-11 function could not be adequately performed at power.
The P-11 Permissive provides the following functions below 2000 psig; (1) allows low pressurizer safety injection to be blocked, (2) allows steamline low pressure safety injection to be blocked, (3) blocks automatic operation of the pressurizer power operated relief valves, (4) blocks the automatic open signal for the safety injection accumulators, (5) enables Main Steam Isolation on high steam pressure rate decrease.
NSAL 97-011 explained that the capability to test the P-11 Permissive from the process protection system at power is limited to the setpoint and does not include the overlap to the SSPS logic input relay since the bistable test switch is opened prior to testing the channel.
Opening the bistable test switch is required by the SSPS system design to satisfy the test logic for safety injection.
Since the SSPS input relay is de-energized above 2000 psig pressurizer, opening of the bistable test switch does not allow the input relay to change state during bistable setpoint verification; and therefore, complete overlap testing for the SSPS input relay is not accomplished.
At 1025 hours0.0119 days <br />0.285 hours <br />0.00169 weeks <br />3.900125e-4 months <br /> on January 21, 1998, this condition was determined to be a violation of TS surveillance requirement 4.3.2.1 due to inadequate past testing of the P-ll Permissive.
TS 4.0.3 was entered at this time to allow proper P-11 testing. NSAL 97-011 recommended that a Technical Specification change be initiated to revise the ACOT surveillance frequency to "Refueling" based on relay reliability and consistency with other Reactor Protection System permissive signals.
Alternately, a modification was also recommended to allow failing of the P-11 function low for testing.
HNP initially elected to revise the surveillance procedure to fail the P-11 low by lifting transmitter leads.
However, during a Harris Plant Engineering review of the proposed procedure changes intended to implement the recommended testing, a potential unreviewed safety question was identified per 10CFR50.59.
This potential unreviewed safety question was related to the failure to comply with single failure criterion of IEEE Standard 338(1971), while in the temporary test configuration.
Based on this concern, it became apparent that testing would not be completed within the allotted 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> per TS 4.0.3; therefore, P-11 was declared inoperable.
After further review, HNP determined that lifting the transmitter leads to fail the P-11 function low was not an unreviewed safety question, provided pressurizer pressure is greater than 2000 psig during the test.
Therefore, HNP will revise surveillance test procedures MST-10122, MST-10123, and MST-10124 to lift the transmitter leads to fail the P-11 function low when testing is performed with pressurizer pressure greater than 2000 psig (normal operating pressurizer pressure is approximately 2235 psig).
Successful completion of these MSTs will restore operability of the P-11 Permissive.
A comprehensive TS surveillance procedure review project is currently in progress to support HNP's conversion to the new Westinghouse Improved Standard Technical Specifications.
This project had not reviewed the surveillance procedures associated with P-11 testing when this condition was identified.
Review of this section of TS and the corresponding surveillance procedures are currently scheduled to begin in mid 1998.
CAUSE
This condition was caused by an inadequate review of initial Technical Specifications for consistency with other permissive signals and the capability for testing SSPS permissive signals at power.
N M
(4 I(4.99)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION u.s. NUCLEAR REGULATORY COMM)ss(ON FACILITY NAME (I)
Shearon Harris Nuclear. Plant
~ Unit PI BUCKET 50 400 LER NUMBER (6)
YEAR SEOU(NNAL BEY)SION NUMBER NUMBER 98 002 01 PAGE(3) 3 OF 3
TEXT N specs spsceis seevied. vse odditdsool copies o/NRC fores 3664! ((1)
SAFETY SIGNIFICANCE
There. were no actual safety consequences associated with the failure to provide complete overlap testing for the P-11 permissive function.
The inability to completely test the P-11 function above 2000 psig pressurizer pressure would potentially cause an inoperable SSPS input relay to remain undetected until pressurizer pressure drops below-2000 psig. Ifthis inoperability existed, the operators would not be able to manually block safety injection. This would be an operational concern, but not a safety issue.
Additionally, the reliability of the SSPS input relays has been excellent.
There have been no failures. of the 258 input relays in 10 years of operation.
This event is being reported as a condition prohibited by TS per 10CFR50.73.a.2.i.B.
PREVIOUS SIMILAREVENTS
LER 97-24 was submitted to the NRC on December 18, 1997.
This LER also reported a SSPS testing deficiency, but was specifically related to a logic card failure scenario.
Therefore, the corrective actions completed for LER 97-24 would not have been expected to identify the P-11 overlap testing issue.
CORRECTIVE ACTIONS PLANNED:
1.
Surveillance test procedures MST-10122, MST-I0123, and MST-I0124 will be revised to include overlap testing of the P-11 Permissive..This will be completed by June 29, 1998.
2.
Surveillance test procedures MST-I0122, MST-I0123, and MST-I0124 will be subsequently performed to restore operability of the P-11 permissive.
This willbe completed by July 22, 1998.