ML20209A978
| ML20209A978 | |
| Person / Time | |
|---|---|
| Issue date: | 03/27/1987 |
| From: | Zech L NRC COMMISSION (OCM) |
| To: | Markey E HOUSE OF REP., ENERGY & COMMERCE |
| Shared Package | |
| ML20209A941 | List: |
| References | |
| NUDOCS 8704280328 | |
| Download: ML20209A978 (8) | |
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kg UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C. 20555 3 "* :. p
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' CHAIRMAN March 27, 1987 The Honorable Edward J. Markey Committee on Energ.y and Commerce United States House of Representatives Washington, D. C. 20515
Dear Congressman Markey:
I am forwarding the. responses .to the questions in your . letter dated January 21, 1987. Those questions addressed.a perceived inconsistency in stated NRC plans concernino acquisition of required experimental data for BAW reactors. I.believe the enclosed responses satisfactorily explain the facts of the matter.
. Commissioner Asselstine disagrees with this response and will provide his views in a separate letter.
Sincerely, (N. d.
Lando W. Ze h,-Jr
Enclosure:
As Stated cc: Rep. Philip Sharp 870422 NRCC (h7042 DR Et4CE PDR CORRE
J QUESTION 1. Please provide a detailed-explanation of the apparent discrepancy between Mr. Stello's memorandum and the Commission's response several weeks earlier to subcommittee questions.
ANSWER.
There are no inconsistencies between Mr. Stello's memorandum and the Commission's response several weeks earlier to Subcommittee questions. The Nuclear Regulatory Commission still believes that additional experimental data is required to assess the capability of best estimate computer codes to accurately predict complex transients in R&W plants. This belief _was indicated in both the April 15, 1986 NRC response and Mr. Stello's April 30, 1986 memorandum.
The April 15, 1986 response indicated an overall need for additional B&W data and stated that NRC planned to obtain the required data. Subsequent to this letter, a detailed plan was developed as discussed below.
Mr. Stello's April 30, 1986 memorandum indicated that because of funding problems, a major piece of this planned research could not be completed as planned. This specific program was the upgrade of the Multi Loop Integral Systems Test (MIST) facility power. The NRC had included funding in the budget for testing in MIST with upgraded power and had been seeking industry support for this additional testing since December 1984 In early 1986, however, it had become apparent that industry was not willing to commit to help support additional testing. Lack of industry support, combined with budget reductions, required that.the staff reevaluate their plans to find a way to obtain the needed data without an upgrade to the MIST power.
During this period, the NRC staff was actively revising the plan in order to obtain the needed data within available funding.
This plan was designed to provide continuity with the existing MIST program and thus initiate testing as soon as possible. The time for completion of the plan would, however, depend on whether or not additional funding could be obtained from industry. Work has already been initiated on several elements of this plan. Key points of this plan and the current status of the elements of the plan are summarized below.
l QUESTION 1 (Continued) -?-
- 1. The current MIST program, jointly funded by NRC and industry, is being conducted at-less cost than originally estimated. This has allowed some additional tests to be added to the current program.
- 2. A more modest follow-on program without a power upgrade, funded by-NRC, has been planned to immediately follow the current program. The contracting process for this additional testing has already been initiated with a-goal of having a new program in place in March or April when the existing test program is completed.- While we are pursuing this follow-on program assuming only government funding, we are still seeking industry support and expect that at least some support will be provided by EPRI.
- 3. In order to fully address all thermal-hydraulic technical issues for R&W plants, the total B&W experimental plan includes integral tests from the current and follow-on MIST programs, two ma,ior separate effects tests of the B&W Once Through Steam Generator (OTSG), and an integral test facility of improved design to provide additional safety information on accidents and other operational problems being experienced in-B&W plants. Scoping tests to be used to design the OTSG Low Pressure Segment Facility (OTSG-LPSF) are underway at the Idaho National Engineering Laboratory. Facility construction would start in FY 1988 with testing completed in FY 1989. The second required separate effects test, OTSG Full Power Operation (OTSG FPO),
will be delayed until after the completion of the MIST follow-on since it will be more cost effective to make use of the MIST steam generator. This test would have been unnecessary if the MIST facility had been upgraded to full power as originally planned. This is the delay discussed in the April 30, 1986 Stello memorandum. Design studies for-the Improved Scale Integral Facility are planned through FY88. A final decision on technical scope is expected at that time after a careful review of accumulated experimental data, industry plans and code assessment requirements.
As indicated by the above discussion, the NRC staff has~
already started to implement a plan to obtain the required
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QUESTION 1-(Continued)' B&W experimental data. -This plan-was modified in the April 1986 period due to lack of industry support. .It:should be noted-that:a recent report.on NRC's;research by the-National. Academy of' Science (NAS)" recommended that industry fund more of this~research. We have actively. sought support' by industry -but industry has rejected ~ funding of this program. The Commission will continue to actively seek industry support for appropriate aspects of research.
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.t OUESTION 2. In light of the absence of experiments needed to validate.the codes in question, and since few such experiments appear to be planned in the near future, should B&W reactors be shut down or their operating levels limited until the computer codes necessary to understand their behavior under accident conditions can be either. verified or rewritten? Please provide a detailed description of the reasons for your answer.
ANSWER.
' Licensing of the B&W plants was based upon the plant safety analyses, contained in the Final Safety Analysis Reports (FSARs),
which were performed.for a range of design basis events. The consequences, such as peak pressure, departure from nucleate boiling, and peak cladding temperature, of these events were obtained using conservative computer codes. That is, the assumptions for these codes were chosen to maximize the consequences. Thus, while continuing experimental and code verification activities will enhance the NRC's ability to better understand and predict B&W plant behavior under accident conditions, the current plant safety analyses are conservative and sufficient to conclude that continued plant operation poses no undue risk to the public health and safety. Therefore, shutdown of the B&W plants, or limitations en their operating power levels, is unnecessary while experimental data is obtained to verify the NRC's best estimate computer codes.
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l 1 l Questions 3.-- Why was'thefinformation~ contained in the Stello=
memorandum not released to' B&W plant' intervenors?_ Why shouldn't relevant;proceedinas which have: terminated be. reopened at-the r'equest i of intervenors, if.the intervenors can present-persuasive evidence that this_information would
?: have ma'terially influenced their ability to argue their position (s)?
i ANSWER There are currently no on-going proceedings involving B&W' plants in which there is any activity,.although there.are two
, open proceedings on the ASLBP docket. .One is.the Three. Mile i Island Unit 1 License. Amendment proceeding concerning the NRC i staff's denial of.a request to use degraded' steam generator tubes, in which the licensee has requested termination of the proceeding. The other involves an application to license Washington Public Power Supply System,-Unit 1, which has-been suspended pending a determination by the applicant on whether 3- to proceed.
The Staff is unaware of any requests from intervenors for.
4 information on the NRC generic research activities with respect i to'B&W plants. Under Commission precedent, reopening of any proceeding because of new information must be in accordance with specified criteria. The criteria for reopening a closed
- proceeding are
- 1. The request to reopen must be timely;
- 2. The' request must present a significant safety or environmental issue, and; I 3. The requestor must show that a different result'might
, have been reached had the newly proffered material been considered initially.
The staff does not view the information in Mr. Stello's' April
, 30, 1986 memorandum as altering the staff conclusions in relevant proceedings concerning B&W plants.
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OVESTION 4. Please provide a detailed description -of the.
current schedule for tests necessary to validate the B&W codes -- including reference to any.
schedule uncertainties that may preclude or delay such experiments.
ANSWER.
A detailed tentative experimental schedule for obtaining the required B&W test data for assessing best estimate codes is attached. Testing has already started and the plan calls for completion of all separate effects testing in FY 1989, with integral testing and analyses conducted in FY 1991. Ma,ior uncertainties in the schedule are as follows: the OTSG-FP0 could be accelerated if significant industry support for the plan is obtained and the OTSG-LPSF cost and schedule are only estimates since the detailed facility design will not be determined until after the completion of the scoping studies being conducted in FY 1987. As mentioned above, detailed plans for the Improved Scale Integral Facility are still being formulated with construction expected to start in FY 89.
_ g- Attach'ont to O.4 TENATIVE SCHEDULE i
_ A tentative schedule to obtain the necessary experimental data is shown
, below. The MIST IV program should be initiated in FY 87 immediately following the MIST III program and completed by the early part of FY 89. MIST' analysis activities would be completed by FY 90. Either the MIST V or the OTSG-FP0 is needed to obtain the necessary thermal hydraulic data for transients initiated from full power. The OTSG visual experiment should be completed in FY 87, followed by the construction and testing of the OTSG-LPSF in FY 88 and FY 89 respectively. Due to,the magnitude of the improved scaled integral fact-lity for the B&W reactor design program, it require an early start. Scaling re-
- view and some preliminary design related work should be completed by FY 88, with construction and shakedown testing scheduled for the next two years. According to this schedule, all MIST- related activities would be completed by the end of FY 90. It provides an acceptable time frame to resolve currently identified 88W technical issues, plus a long term ISIF program to position NRC for prompt reso-lution of future B&W issues. !
EXPERIMENTAL FACILITIES AND SUPPORT PROGRAMS :
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- 1. Thermal Hydraulic Technical Integration Center l
- 2. OTSG Visual Loop " !
- 3. MIST Analysis
- 4. MIST-IV
- 5. OTSG Full Power Operation (OTSG-FPO)
- 6. OTSG Low Pressure Segment Facility (OTGS-LPSF)
- 7. Improved Scaled Integral Facility
- 8. (NEL Site Upgrade "
. 9. UMCP 2x4 Loop j 10. ANL Modelling of Two-Phase Flow
- 11. MIST-V l
SCHEDULE FY 87 FY 88 FY 89 FY 90 Total :
Estimated l Cost MIST-IV xxxxxxxxxxxxxxxxxxxxx $2.1M
, MIST-V or OTSG-FP0 xxxxxxxxxxxxxxxxxxxxx $10.1M or $3.0M 3
MIST Analysis xxxxxxxxxxxxxxxxxxxxxxxxxxxxx $3.5M OTSG Visual Experiment xxxxx $0.5M INEL Site Upgrade xxxxxxxxxxxxx $6.0M OTSG-LPSF xxxxxxxxxxxxxxxxxxxxx $11.8M a
ISIF xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx $1.4M TIC xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx $5.7M I UMCP 2x4 Loop xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx $1.2M 1
ANL xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx $1.1M l
- a. for scaling review and preliminary design related work only i
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