ML17258B198
| ML17258B198 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/26/1981 |
| From: | Maier J ROCHESTER GAS & ELECTRIC CORP. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8109010234 | |
| Download: ML17258B198 (18) | |
Text
REBULAT+ INFORMATION: DISTRIBUTIONeISTEM (RIBS)
ACCESSION NBRe8109010234 DOC ~ DATE ~ 81/08/26 NOTARIZED:
NO DOCKET FACILE:50-244 Robert Emmet Ginna Nuclear >> Planti Unit 1p Rocheste'r G
05000244 AUTH~,NAME!
AUTHOR AFFILIATION MAIER'gJ ~ E',
Rochester Gas 8 Electric Corp+
RECIP ~ NAMEI RECIPIENT AFFILIATION CRUTCHFIELDFD, Operating Reactors Branch 5
SUBJECT:
For wards response to B10526 safety evaluation require'xgnts re. valve inset vice. testing. program.No addi leak testing on Valves 700F701F720 L 721 required.
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e zz ir ROCHESTER GAS AND ELECTRIC CORPORATION o
89 EAST AVENUE, ROCHESTER, N.Y. 14649 JOHN E.
MAILER VICE PRESIDENT TKKKPHONK ARKA COOK Tld 546.2700 August 26, 1981 Director of Nuclear Regulation Attention:
Dennis M. Crutchfield, Chief Operating Reactor Branch 55 U.
S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Inservice Valve Testing Program R.
E. Ginna Nuclear Power Plant Unit 51 Docket No. 50-244
Dear Mr. Crutchfield:
Your letter dated May 26, 1981 granted relief from certain of the American Society of Mechanical Engineers (ASME) Code Section XI valve testing requirements.
The accompanying safety evaluation contained several sections which required a response from RG6E.
The attachment to this letter provides those responses.
Your letter particularly directed our attention to three sections of the safety evaluation, 1.1.1, 1.1.6 and 1.1.8.
We were requested to provide responses to these sections in 90 days, 120 days and 120 days respectively.
Our response to sections 1.1.1 and 1.1.8 are included in the attachment to this letter.
Our response to section 1.1.6 will be delayed,
- however, we agree to provide the technical specification review which you requested.
Although not required, we are also providing a response or clari-fication for sections 1.1.4, 1.1.5, 1.1.9 and 1.1.10 of the safety evaluation.
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Very truly yours, J
n E. Maier Attachment goV>
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RESPONSE
TO SAFETY EVALUATION INSERVICE TESTING PROGRAM VALVES ROCHESTER GAS Sc ELECTRIC CORPORATION R. E.
GINNA NUCLEAR POWER PLANT DOCKET NO. 50-244 August 1981
The responses given in this document are numbered to correspond with the numbering. of the Office of Nuclear Reactor Regulation Safety Evaluation which was sent to Rochestex Gas and Electric with Mr. Dennis Crutchfield's May 26, 1981 letter.
The safety evaluation is repeated here for those sections requiring a response.
1.1.1 Testin of Valves Which Perform a Pressure Isolation Function Several safety, systems connected to the reactor coolant pressure boundary have design pressures below the reactor coolant system operating pressure.
Redundant isolation valves within the Class 1 boundary forming the interface between these high and low pressure systems prevent the low pressure systems from (sic) pressures which exceed their design limit.
In this role, the valves perform a pressure isolati.on function.
We view as important the redundant isolation provided by these valves.
We consider it necessary to assure that the condition of each of these valves is adequate to maintain this redundant isolation and system integrity.
For these
- reasons, we believe that some method, such
'as pressure monitoring, leak testing, radiography and ultrasonic testing should be used to assure (sic) the condition of each valve is satisfactory in maintaining this pressure isolation function.
If leak testing is selected as the appropriate method for achieving this objective, the staff believes that the following valves should be categorized as A or AC and leak tested according to IWV-3420 of Secti,on XI of the applicable edition of the ASME Code.
These valves are:
853A (Core Deluge Check) 853B (Core Deluge Check) 878J (1-B SI Pump to Cold Leg Loop A) 878G (1-A SI Pump to Cold Leg Loop B) 852A (RHR Pump to RX Vessel) 852B (RHR Pump to RX Vessel) 842A (First Check Valve in Loop A ACC Dump Line) 842B (First Check Valve in I,oop B ACC Dump Line) 867A (ACC Dump and SI to Cold I,eg Loop B) 867B (ACC Dump and SI to Cold Leg Loop A) 700 (Suction Stop from Ioop A Hot Leg to RHR Pumps) 701 (Suction Stop from Loop A Hot I,eg to RHR Pumps) 720 (RHR Pump Discharge to Cold Leg Loop B) 721 (RHR Pump Discharge to Cold Leg Loop B) 877A (First Check Valve in Loop B Hot Leg) 878F (Second Check Valve in Loop B Hot Ieg) 877B (First Check Valve in Loop A Hot Leg) 878H (Second Check Valve in Ioop A Hot Ieg)
We have discussed this matter with the licensee and identified the valves listed above.
The licensee agreed to consider testing and catt:gorizing each of these valves with the appropriate designation depending on the testing method selected.
Whatever method the licensee selects for determining the condition of each valve, the licensee will provide to the NRC for evaluation the details of the testing method which clearly demonstrate the condition of each valve.
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The licensee should be aware that some of the above listed valves may be associated with the Event V configuration issue expressed in our letter to the licensee dated February 23, 1980. If the licensee action as a result, of this and other followup NRC letters on this subject matter is to test the valves, then the licensee should identify the valves and provide us the testing method and procedure if they have not already done this.
The February 23, 1980 letter was the initiation on our part to accelerate our effort to begin having licensees testing pressure isolation valves. It is the staff position that all pressure isolation valves identified in this section must be considered for testing.
~Res onse The following valves are covered by Technical Specification 4,3.3.
853A 853B 878J 878G 867A 867B 877A 877B 878F 878H Valves 853A,
- 853B, 878J,
- 878G, 867A and 867B are currently classified as category C valves under the definitions of the ASME Boiler and Pressure Vessel Code Section XI (Section XI) Article IWV-2000.
These valves are tested for leakage after refueling and cold shutdowns, and after maintenance, repair or replacement.
In addition, valves 878G and 878J are tested for leakage after each safety injection flow test. (monthly).
The frequency of testing for 853A,
- 853B, 867A and 867B is appropriate and meets the requirements of Section XI, IWV-3412 for valves which can not be practicably operated during normal operation.
The testing of 878G and 878J meets the quarterly test frequency requirements of IWV-3411.
The leakage from the valves is limited to less than 5
gpm by Technical Specification 4.3.3.
Thus the classification of these valves will be changed in our inservice valve test program to active categories A and C with test frequencies as discussed above.
Valves 877A,
- 877B, 878F and 878H are currently not listed in our valve test program,
- however, a pair of these valves in each hot, leg high head safety injection line (877A and 878F in loop B
hot. leg and 877B and 878H in loop A hot leg) together form one of the two pressure boundaries required to be tested by Technical Specification 4.3.3.3.
Because these valves are normally closed and the piping contains motor operated valves (MOV's) which are also closed and deenergized, the check valves will not move with the possible exception of When the MOVs are required to be opened,
3 to test the check valves.
- Thus, once tested the check valves will remain closed.
An NRC order dated April 20, 1981 established an appropriate test frequency for these valves to be once every 40 months or after each opening of the MOVs.
In the future, these valves will be listed as passive category A valves in our valve testing program with testing required to meet Technical Specification 4.,3.3.3.
Check valves 842A and 842B (accumulator check valves) are currently listed as category C valves in our valve testing pxogram.
The valves cannot and should not be exercised during plant operation.
Exercising of these valves requires that reactor coolant system pressure be reduced to below accumulator pressure.
Therefore we propose to modify our inservice test program to include testing of these valves after refueling and cold shutdowns and after maintenance, repair or replacement.
Leak testing will be per-formed to assure primary system integrity by (1) closing each accumulator motor operated discharge valve, pressurizing the line downstream of the check valves and measuring the upstream
- leakage, or (2) measuring accumulator in-leakage by pressurizing the line downstream of the 842 valves.
Our valve testing program will be revised to'ist these valves as active categories A and C.
MOVs 700,
- 701, 720 and 721 are category B valves which should not and cannot be exercised during plant operation.
The valves are normally closed and in the position required to ful-filltheir safety function during power operation.
The valves are motor operated with valve position indicated in the control room.
After closing these valves, power is removed at the breaker to prevent inadvertent operation.
Valves 700 and 721 are inter-.
locked with RCS pressure to prevent inadvertent opening.
Valves 701 and 720 have key lock switches on the control board to prevent inadvertent opening.
Because of the sizing of the valve operator, it is physically impossible for the valves to be opened with a pressure di,fferential across the valve of 500 psi or more.
Acceptably low leakage through each pair of valves is demonstrated during each system pressure test following refueling.
A relief valve capable of passing 200 gpm provides relief from the lower pressure RHR piping to the pressurizer relief tank.
An increase in leakage through the valves during operation would be detected by discrepancies in makeup and letdown rates, by pressurizer relief tank indications, or by RHR system pressure and temperature indication.
Additional discussion on these RHR valves concerning SEP Topic V-11.A is included in Mr. Dennis M. Crutchfield's letter to Mr. John E. Maier dated July 22, 1981 and in Mr. Maier's letter to Mr. Crutchfield dated June 23, 1981.
WASH 1400 (NUREG-75/014) concluded that piping connections to the reactor coolant system "...have the potential to cause a
LOCA in which the interior of the reactor vessel may communicate to the environment.
All except the LPIS check valve situation...
were dismissed for any or a combination 'of the following reasons:
a.
The multiplicity of barriers that would be required to fail would render the LOCA much less probable than the check valves.
b.
Failure of the barriers would not involve loss of vital safeguards and, the loss of RCS coolant could be accommodated within the design of the interfacing systems through safety and relief provisions, and the coolant loss could be controlled or contained without a core melt occurring.
c.
Failure of the barriers would involve a LOCA into the containment and would, therefore, be covered by previous IOCA event trees."
In addition, testing of these valves on an individual basis would require that test personnel work on these lines at times when the reactor coolant system temperature is greater than 350'F-The valves are open and in service at lower temperatures.
These conditions would subject personnel to high temperature fluid hazards when connecting or disconnecting test equipment and would give them an unnecessary radiation exposure while working in the containment building near the primary loops.
The dose rate near these valves is approximately 100 mr/hour during reactor outages.
Therefore, we have concluded that additional leak testing beyond that already performed on 700,
- 701, 720 and 721 should not be required.
MOVs 852A and 852B are category B valves which should not be exercised during power operation.
These valves provide the second of two boundaries between the reactor coolant system (RCS) and the lower pressure residual heat removal (RHR) system.
The valves are normally closed to fulfilltheir pressure isolation function.
One of the two valves is required tq open to mitigate large LOCAs (>four inch diameter break).
Stroking 852A and 852B during power operation will mean that the boundary between the RCS and the RHR system will be formed by a single check valve.
Thus, stroke testing of 852A and 852B is appropriate only during cold and refueling shutdowns consistent with our current valve testing program.
Valves 852A and 852B are provided with position indication in the control room.
Acceptably low leakage through each pair of valves is demonstrated during each system pressure test following refueling.
A relief valve capable of pasqing 200 gpm provides relief from the lower pressure RHR piping to the pressurizer relief tank.
An increase in leakage through the valves during operation would be detected by discrepancies in makeup and let-down rates, by pressurizer relief tank indications, or by RHR system pressure and temperature indication.
Additional leak testing beyond that already performed should not be required.
Leakage from valves
- 700, 701,
- 720, 721, 852A and 852B may be substantial (up to 200 gpm) without any overpressurization effects upon the RHR system,
- however, Technical Specification 3.1,5 requires a plant shutdown for any leakage which is greater than 10 gpm.
Categorization of these valves as category B in our valve testing program is appropriate because the seat leakage is not limited to a'pecific maximum amount and seat leakage is inconsequential for the fulfillment of their function.
Test procedures for the valves listed in this section will be available for inspection at, Ginna Station.
For those valves which have not previously b'eel required, to,be tested (842A and 842B), procedures gill be available no later than the first test which will be required in accordance with our commitments in this letter.
SER 1.1.4 Test Fre uenc of Check Valves Tested at Cold Shutdowns Thy Code states that, in the case of frequent cold shutdowns, valve testing need not be performed more often than once every three months for Category A
and B valves and once every nine months for Category C valves (check valves only). It 'is our position that Category C valves should be tested on the same schedule as Category A and B valves.
This position is also in agreement with the current edition and addenda of the Code.
The licensee has agreed to this position that valve testing will not be performed more often than once every three (3) months for Category A, B, and C valves.
R~es ense The testing frequency for Category C check valves in our inservice valve testing program is generally once every quarter except where plant conditions make testing not practical during plant operation.
Valves which cannot be practically tested during operation are required to be tested during cold and re-fueling shutdowns.
The testing requirements for type C valves are clearly identified in the valve testing program, Appendix C
to the Quality Assurance Manual.
. We agree that valve testing during cold shutdowns should be on a frequency determined as follows:
for intervals between cold shutdowns of 3 months or longer, exercise during each shutdown; for intervals of less than 3 months, exercising is not required unless 3 months have passed since the last shutdown exercise.
SER 1.1.5 Licensee Re uest for Relief to Test, Valves at Cold Shutdown The Code permits valves to be tested at cold shutdown, and the Code conditions under which this is permitted are noted in Attachment A.
These valves are specifically identified by the licensee and are full-stroke exercised during cold shutdowns; therefore, the licensee is meeting the requirements of the
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ASHE Code and it will not be necessary to grant relief.
However, during our review of the licensee's IST program, we have verified that it was not practical to exercise these valves during power operation and that we agree with the licensee's basis.
It should be noted that the staff diffezentiates for valve testing purposes between the cold shutdown mode and the refueling mode.
That is, for testing purposes the refueling mode is not considered as a cold shutdown.
~Res ense The staff differentiation for valve testing purposes between the cold shutdown mode and the refueling mode is unclear.
A refueling shutdown is defined by Technical Specification 1.2 as Tavg
< 140'F and bK/K reactivity
< - 10%.
Cold shutdown is Tavg
< 200'F and bK/K reactivity 1/.
Thus refueling shutdown conditions are a subset of cold shutdown conditions and all testing done duxing refueling conditions is also considered to have been done at cold shutdown.
SER 1.1.6 Chan es to the Technical S ecification In a November 3.976 letter to the licensee, we provided an attachment entitled "NRC Guidelines for Excluding Exercising (Cycling) Tests of Certain Valves During Plant Operation."
The attachment stated that when one train of a redundant system such as in the Emergency Core Cooling System (ECCS) is inoperable, nonredundant valves in the remaining train should not be cycled if their failure in a non-safe position would cause a loss of total system function.
For example, during power operation in some plants, there are stated minimum requirements for systems which allow certain limiting con-ditions for operation to exist at any one mme and if the system is not restored to meet the requirements within tAe time period specified in a plant's Technical Specifications (T.S.),.the reactor is required to be put in some other mode.
Furthermore, prior to initiating reports, all valves and interlocks in the system that provide a duplicate function are required to be tested to demonstrate operability immediately and periodically thereafter during power operation.
For such plants this situation could be contrary to the NRC guideline as stated in the document mentioned above.
It should be noted that reduction in redundancy is not a basis for a T.S.
change nor is it by itself a basis for relief from exercising in accordance with Section XI.
The licensee has agreed to review the plant's T.S.
and to consider the need to propose T.S.
change which would have the effect of precluding such testing.
After making this review, if the licensee determines that the T.S. should be changed because the guidelines are applicable, the licensee will submit to the NRC in conjunction with the proposed T.S.
- change, the inoperable condition for each system that is affected which demonstrates that the valve's failure would cause a loss of system function.
Conversely, if the licensee determines that the T,S. should not be changed because the guidelines are not applicable or cannot be followed, the licensee will submit the reasons that led to their determination for each potentially affected section of the T,S.
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~Res onse We will review the plant technical specifications and consider the need for changes to preclude undesixeable testing.
- However, our review and technical specification changes which may result from the review will not, be completed within 120 days as suggested in the SER cover letter.
Due to the press of other work, the review will probably not be completed before the end of 1981.
SER 1.1.8 Valve Testin at Cold Shutdown Inservice valve testing at cold shutdown is acceptable when the following conditions are met. It is understood that the licensee is t'o commence testing within two hours after cold shutdown condition, is achieved but not later than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after shutdown and continue until complete or plant is ready to return to power.
Completion, of all valve testing is not a prerequisite to return to power.
Any testing not.completed at one cold shutdown should be performed during any subsequent cold shutdowns that may occur before refueling to meet the Code-specified testing frequency.
For planned cold shutdowns, where the licensee will complete all the valves identified in his IST program for testing in the cold shutdown mode, exceptions to the 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> may be taken.
The licensee has agreed to consider testing in accordance with these requirements.
~Res onse The testing of valves required at cold shutdown and refueling outages will normally take four (4) days to complete.
When cold shutdowns are of a shorter duration (2-3 days), test personnel attempt to test as many valves as possible without holding up the startup of the unit with testing beginning no longer than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after the plant reaches cold shutdown (as defined in Technical Specification 1.2).
For very short cold shutdowns (less than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />), it is impossible to mobilize test personnel to implement the testing program under the required procedural controls, therefore no valves are required to be tested.
It is possible that, during a four (4) day cold shutdown, the work load on test personnel may preclude their completion of all the required valve tests prior to startup.
Valve testing during cold shutdowns need not be more frequent than one test per quarter for each valve in the test program.
A requirement for testing at cold shutdown no later than two hours after reaching cold shutdown and no later than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after shutdown is impractical and may be impossible in some circumstances.
The plant may not be in cold shutdown within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of shutdown on some occasions.
Test, personnel may not. be available within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after reaching cold shutdown if'the cooldown is rapid.
Our commitment to begin testing no longer than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after the plant reaches cold shutdown is appropriate.
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SER 1.1.9 Cate or A Valve I,eak Check Re uirements for Containment Isolation Valves (CIV)
All CIVs shall be classifi'ed as Category A valves.
The Category A valve leak rate test requirements of IWV-3420 (a-e) have been superseded by Appendix J requirements for CIVs.
The staff has concluded that the applicable leak test procedures and requirements for CIVs are determined by 10 CFR 50 Appendix J.
Relief from paragraph IWV-,3420 (a-e) for CIVs presents no safety problem since the intent of IWV-3420,(a-e),', 'w'hich is to demonstrate,,theak'ightness of the valves, is met by Appendix,J requirements.
The licensee shall -comply with Sections f and g of IWV-3420 until relief is requested from these paragraphs.
It should be, noted that these paragraphs are only applicable 'where a Type C Appendix J leak test "is performed.
Based on the considerations discussed
- above, the staff concludes that the alternate testing proposed above will give the reasonable assurance of valve operability intended by the Code and that the relief thus granted will not endanger life or property or the common defense and security of the public.
R~es onse Sections f and g of IWV-3420 re ferred to above are apparently paragraphs in the 1974 version of the ASME code.
Our current valve testing program is based upon the 1977 version of the code with addenda through Summer 1978. It is correct that the require-ments of IWV-3420 (a-e) have been superceded by Appendix J to 10 CFR Part 50.
The leakage limits and repair requirements of the 1974 IWV-3420 sections f and g are superceded by the more recent code and Technical Specification 4.4.2.
A relief request from 1974 IWV-3420 sections f and g is not applicable.
SER 1.1,10 A lication of A endix J Testin to the IST Pro ram The Appendix J review for this plant is completely separate review from the IST program review.
However, the determinations made by that review are directly applicable to the IST program.
Our review has determined that the current IST program as submitted by the licensee correctly reflects our inter-pretation of Section XI vis-a-vis Appendix J.
The licensee has agreed that, should the Appendix J program be amended, they will amend their IST program accordingly.
~Res onse Appropriate amendments to the inservice test program will be considered if the Appendix J program is revised.
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